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Sample records for aerobic growth defect

  1. Media for the aerobic growth of campylobacter

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of agar and sodium bicarbonate (NaHCO3) concentration on aerobic growth of Campylobacter in a fumarate-pyruvate medium was examined. The broth medium was supplemented with 0.0 to 0.2% agar and inoculated with 106 CFU/ml of Campylobacter coli 33559, Campylobacter fetus 27349, Campylobacter...

  2. Growth of Campylobacter Incubated Aerobically in Media Supplemented with Peptones

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Growth of Campylobacter cultures incubated aerobically in media supplemented with peptones was studied, and additional experiments were conducted to compare growth of the bacteria in media supplemented with peptones to growth in media supplemented with fumarate-pyruvate-minerals-vitamins (FPMV). A b...

  3. Aerobic and anaerobic growth of Paracoccus denitrificans on methanol.

    PubMed

    Bamforth, C W; Quayle, J R

    1978-10-01

    1. The dye-linked methanol dehydrogenase from Paracoccus denitrificans grown aerobically on methanol has been purified and its properties compared with similar enzymes from other bacteria. It was shown to be specific and to have high affinity for primary alcohols and formaldehyde as substrate, ammonia was the best activator and the enzyme could be linked to reduction of phenazine methosulphate. 2. Paracoccus denitrificans could be grown anaerobically on methanol, using nitrate or nitrite as electron acceptor. The methanol dehydrogenase synthesized under these conditions could not be differentiated from the aerobically-synthesized enzyme. 3. Activities of methanol dehydrogenase, formaldehyde dehydrogenase, formate dehydrogenase, nitrate reductase and nitrite reductase were measured under aerobic and anaerobic growth conditions. 4. Difference spectra of reduced and oxidized cytochromes in membrane and supernatant fractions of methanol-grown P. denitrificans were measured. 5. From the results of the spectral and enzymatic analyses it has been suggested that anaerobic growth on methanol/nitrate is made possible by reduction of nitrate to nitrite using electrons derived from the pyridine nucleotide-linked dehydrogenations of formaldehyde and formate, the nitrite so produced then functioning as electron acceptor for methanol dehydrogenase via cytochrome c and nitrite reductase. PMID:718372

  4. C4-Dicarboxylate Utilization in Aerobic and Anaerobic Growth.

    PubMed

    Unden, Gottfried; Strecker, Alexander; Kleefeld, Alexandra; Kim, Ok Bin

    2016-06-01

    C4-dicarboxylates and the C4-dicarboxylic amino acid l-aspartate support aerobic and anaerobic growth of Escherichia coli and related bacteria. In aerobic growth, succinate, fumarate, D- and L-malate, L-aspartate, and L-tartrate are metabolized by the citric acid cycle and associated reactions. Because of the interruption of the citric acid cycle under anaerobic conditions, anaerobic metabolism of C4-dicarboxylates depends on fumarate reduction to succinate (fumarate respiration). In some related bacteria (e.g., Klebsiella), utilization of C4-dicarboxylates, such as tartrate, is independent of fumarate respiration and uses a Na+-dependent membrane-bound oxaloacetate decarboxylase. Uptake of the C4-dicarboxylates into the bacteria (and anaerobic export of succinate) is achieved under aerobic and anaerobic conditions by different sets of secondary transporters. Expression of the genes for C4-dicarboxylate metabolism is induced in the presence of external C4-dicarboxylates by the membrane-bound DcuS-DcuR two-component system. Noncommon C4-dicarboxylates like l-tartrate or D-malate are perceived by cytoplasmic one-component sensors/transcriptional regulators. This article describes the pathways of aerobic and anaerobic C4-dicarboxylate metabolism and their regulation. The citric acid cycle, fumarate respiration, and fumarate reductase are covered in other articles and discussed here only in the context of C4-dicarboxylate metabolism. Recent aspects of C4-dicarboxylate metabolism like transport, sensing, and regulation will be treated in more detail. This article is an updated version of an article published in 2004 in EcoSal Plus. The update includes new literature, but, in particular, the sections on the metabolism of noncommon C4-dicarboxylates and their regulation, on the DcuS-DcuR regulatory system, and on succinate production by engineered E. coli are largely revised or new. PMID:27415771

  5. Assessment of Aerobic and Respiratory Growth in the Lactobacillus casei Group

    PubMed Central

    Zotta, Teresa; Ricciardi, Annamaria; Ianniello, Rocco G.; Parente, Eugenio; Reale, Anna; Rossi, Franca; Iacumin, Lucilla; Comi, Giuseppe; Coppola, Raffaele

    2014-01-01

    One hundred eighty four strains belonging to the species Lactobacillus casei, L. paracasei and L. rhamnosus were screened for their ability to grow under aerobic conditions, in media containing heme and menaquinone and/or compounds generating reactive oxygen species (ROS), in order to identify respiratory and oxygen-tolerant phenotypes. Most strains were able to cope with aerobic conditions and for many strains aerobic growth and heme or heme/menaquinone supplementation increased biomass production compared to anaerobic cultivation. Only four L. casei strains showed a catalase-like activity under anaerobic, aerobic and respiratory conditions and were able to survive in presence of H2O2 (1 mM). Almost all L. casei and L. paracasei strains tolerated menadione (0.2 mM) and most tolerated pyrogallol (50 mM), while L. rhamnosus was usually resistant only to the latter compound. This is the first study in which an extensive screening of oxygen and oxidative stress tolerance of members of the L. casei group has been carried out. Results allowed the selection of strains showing the typical traits of aerobic and respiratory metabolism (increased pH and biomass under aerobic or respiratory conditions) and unique oxidative stress response properties. Aerobic growth and respiration may confer technological and physiological advantages in the L. casei group and oxygen-tolerant phenotypes could be exploited in several food industry applications. PMID:24918811

  6. Influence of bovine lactoferrin on the growth of selected probiotic bacteria under aerobic conditions.

    PubMed

    Chen, Po-Wen; Ku, Yu-We; Chu, Fang-Yi

    2014-10-01

    Bovine lactoferrin (bLf) is a natural glycoprotein, and it shows broad-spectrum antimicrobial activity. However, reports on the influences of bLf on probiotic bacteria have been mixed. We examined the effects of apo-bLf (between 0.25 and 128 mg/mL) on both aerobic and anaerobic cultures of probiotics. We found that bLf had similar effects on the growth of probiotics under aerobic or anaerobic conditions, and that it actively and significantly (at concentrations of >0.25 mg/mL) retarded the growth rate of Bifidobacterium bifidum (ATCC 29521), B. longum (ATCC 15707), B. lactis (BCRC 17394), B. infantis (ATCC 15697), Lactobacillus reuteri (ATCC 23272), L. rhamnosus (ATCC 53103), and L. coryniformis (ATCC 25602) in a dose-dependent manner. Otherwise, minimal inhibitory concentrations (MICs) were 128 or >128 mg/mL against B. bifidum, B. longum, B. lactis, L. reuteri, and L. rhamnosus (ATCC 53103). With regard to MICs, bLf showed at least four-fold lower inhibitory effect on probiotics than on pathogens. Intriguingly, bLf (>0.25 mg/mL) significantly enhanced the growth of Rhamnosus (ATCC 7469) and L. acidophilus (BCRC 14065) by approximately 40-200 %, during their late periods of growth. Supernatants produced from aerobic but not anaerobic cultures of L. acidophilus reduced the growth of Escherichia coli by about 20 %. Thus, bLf displayed a dose-dependent inhibitory effect on the growth of most probiotic strains under either aerobic or anaerobic conditions. An antibacterial supernatant prepared from the aerobic cultures may have significant practical use. PMID:24916115

  7. Effect of bicarbonate concentration on aerobic growth of campylobacter in a fumarate-pyruvate medium

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The purpose of the present study was to examine the effect of sodium bicarbonate (NaHCO3) concentration on aerobic growth of Campylobacter in a fumarate-pyruvate medium. Fumarate-pyruvate broth medium was supplemented with 0.00 to 0.10% NaHCO3 and inoculated with Campylobacter coli 33559, Campyloba...

  8. Enhancing Aerobic Growth of Campylobacter in Media Supplemented with Organic Acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of agar and sodium bicarbonate (NaHCO3) concentration on aerobic growth of Campylobacter in was determined. A fumarate-pyruvate medium was supplemented with 0.0 to 0.2% agar and inoculated with Campylobacter coli, Campylobacter fetus, or Campylobacter jejuni. Portions of the inoculated me...

  9. Aerobic glycolysis in the primate brain: reconsidering the implications for growth and maintenance.

    PubMed

    Bauernfeind, Amy L; Barks, Sarah K; Duka, Tetyana; Grossman, Lawrence I; Hof, Patrick R; Sherwood, Chet C

    2014-07-01

    Glucose metabolism produces, by oxidative phosphorylation, more than 15 times the amount of energy generated by aerobic glycolysis. Nonetheless, aerobic glycolysis remains a prevalent metabolic pathway in the brain. Here we review evidence suggesting that this pathway contributes essential molecules to the biomass of the brain. Aerobic metabolism is the dominant metabolic pathway during early postnatal development when lipids and proteins are needed for the processes of axonal elongation, synaptogenesis, and myelination. Furthermore, aerobic metabolism may continue into adulthood to supply biomolecules for activity-related changes at the synapse and turnover of constituent structural components of neurons. Conversely, oxidative phosphorylation appears to be the main metabolic support for synaptic transmission, and, therefore, this pathway seems to be more dominant in brain structures and at time points in the lifespan that are characterized by increased synaptic density. We present the case for differing relationships between aerobic glycolysis and oxidative phosphorylation across primates in association with species-specific variation in neurodevelopmental trajectories. In doing so, we provide an alternative interpretation for the assessment of radiolabeled glucose positron emission tomography studies that regularly attribute increases in glucose uptake to neural activity alone, and propose a new model for the contribution of metabolic pathways for energetic demand and neural tissue growth. We conclude that comparative studies of metabolic appropriation in the brain may contribute to the discussion of human cognitive evolution and to the understanding of human-specific aging and the etiology of neuropsychiatric diseases. PMID:24185460

  10. Role of phosphate solubilizing bacteria on rock phosphate solubility and growth of aerobic rice.

    PubMed

    Panhwar, Q A; Radziah, O; Zaharah, A R; Sariah, M; Razi, I Mohd

    2011-09-01

    Use of phosphate-solubilizing bacteria (PSB) as inoculants has concurrently increased phosphorous uptake in plants and improved yields in several crop species. The ability of PSB to improve growth of aerobic rice (Oryza sativa L.) through enhanced phosphorus (P) uptake from Christmas island rock phosphate (RP) was studied in glasshouse experiments. Two isolated PSB strains; Bacillus spp. PSB9 and PSB16, were evaluated with RP treatments at 0, 30 and 60 kg ha(-1). Surface sterilized seeds of aerobic rice were planted in plastic pots containing 3 kg soil and the effect of treatments incorporated at planting were observed over 60 days of growth. The isolated PSB strains (PSB9 and PSB16) solubilized significantly high amounts of P (20.05-24.08 mg kg(-1)) compared to non-inoculated (19-23.10 mg kg(-1)) treatments. Significantly higher P solubilization (24.08 mg kg(-1)) and plant P uptake (5.31 mg plant(-1)) was observed with the PSB16 strain at the highest P level of 60 kg ha(-1). The higher amounts of soluble P in the soil solution increased P uptake in plants and resulted in higher plant biomass (21.48 g plant(-1)). PSB strains also increased plant height (80 cm) and improved root morphology in aerobic rice. The results showed that inoculation of aerobic rice with PSB improved phosphate solubilizing activity of incorporated RP. PMID:22319876

  11. Fatigue crack growth testing of sub-clad defects

    SciTech Connect

    Jones, D.P.; Leax, T.R.

    1998-04-01

    Fatigue crack growth tests were performed on four point bend specimens with crack like defects intentionally placed in A302B low-alloy pressure vessel steel clad with 308/309L weld deposited stainless steel. The defects were placed in the base metal under the cladding by machining a cavity from the side opposite the cladding, electric-discharge machining a very sharp flaw, fatigue pre-cracking the flaw, and then filling up the cavity by a weld repair process. The specimens were stress relieved before fatigue testing. The specimens were fatigue cycled at positive load ratios until the defects broke through to the surface. The specimens were then fractured at liquid nitrogen temperatures to reveal the fracture surfaces. Seven different sub-clad flaw specimens were tested in room temperature air and each test provides a record of cycles to defect break-through. Changes in defect size and shape as a function of applied load cycles were obtained by benchmarking the crack at various stages of the load history. The results provide a set of embedded defect data which can be used for qualifying fatigue crack growth analysis procedures such as those in Section XI of the ASME Boiler and Pressure Vessel Code. A comparison between calculated and measured values shows that the ASME B and PV Section XI fatigue crack growth procedures conservatively predict cycles to defect break-through for small sub-clad defects.

  12. Investigation of plasmid-induced growth defect in Pseudomonas putida.

    PubMed

    Mi, Jia; Sydow, Anne; Schempp, Florence; Becher, Daniela; Schewe, Hendrik; Schrader, Jens; Buchhaupt, Markus

    2016-08-10

    Genetic engineering in bacteria mainly relies on the use of plasmids. But despite their pervasive use for physiological studies as well as for the design and optimization of industrially used production strains, only limited information about plasmid induced growth defects is available for different replicons and organisms. Here, we present the identification and characterization of such a phenomenon for Pseudomonas putida transformants carrying the pBBR1-derived plasmid pMiS1. We identified the kanamycin resistance gene and the transcription factor encoding rhaR gene to be causal for the growth defect in P. putida. In contrast, this effect was not observed in Escherichia coli. The plasmid-induced growth defect was eliminated after introduction of a mutation in the plasmid-encoded rep gene, thus enabling construction of the non-toxic variant pMiS4. GFP reporters construct analyses and qPCR experiments revealed a distinctly lowered plasmid copy number for pMiS4, which is probably the reason for alleviation of the growth defect by this mutation. Our work expands the knowledge about plasmid-induced growth defects and provides a useful low-copy pBBR1 replicon variant. PMID:27287537

  13. By reducing hexokinase 2, resveratrol induces apoptosis in HCC cells addicted to aerobic glycolysis and inhibits tumor growth in mice

    PubMed Central

    Xia, Yujing; He, Lei; Chen, Kan; Li, Jingjing; Li, Sainan; Liu, Tong; Zheng, Yuanyuan; Wang, Jianrong; Lu, Wenxia; Zhou, Yuqing; Yin, Qin; Abudumijiti, Huerxidan; Chen, Rongxia; Zhang, Rong; Zhou, Li; Zhou, Zheng; Zhu, Rong; Yang, Jing; Wang, Chengfen; Zhang, Huawei; Zhou, Yingqun; Xu, Ling; Guo, Chuanyong

    2015-01-01

    Cancer cells exhibit an altered metabolic phenotype known as the aerobic glycolysis. The expression of HK2 changes the metabolic phenotype of cells to support cancerous growth. In the present study, we investigated the inhibitory effect of resveratrol on HK2 expression and hepatocellular carcinoma (HCC) cell glycolysis. Aerobic glycolysis was observed in four HCC cell lines compared to the normal hepatic cells. Resveratrol sensitized aerobic glycolytic HCC cells to apoptosis, and this effect was attenuated by glycolytic inhibitors. The induction of mitochondrial apoptosis was associated with the decrease of HK2 expression by resveratrol in HCC cells. In addition, resveratrol enhanced sorafenib induced cell growth inhibition in aerobic glycolytic HCC cells. Combination treatment with both reagents inhibited the growth and promoted apoptosis of HCC-bearing mice. The reduction of HK2 by resveratrol provides a new dimension to clinical HCC therapies aimed at preventing disease progression. PMID:25938543

  14. A performance evaluation of three membrane bioreactor systems: aerobic, anaerobic, and attached-growth.

    PubMed

    Achilli, A; Marchand, E A; Childress, A E

    2011-01-01

    Water sustainability is essential for meeting human needs for drinking water and sanitation in both developing and developed countries. Reuse, decentralization, and low energy consumption are key objectives to achieve sustainability in wastewater treatment. Consideration of these objectives has led to the development of new and tailored technologies in order to balance societal needs with the protection of natural systems. Membrane bioreactors (MBRs) are one such technology. In this investigation, a comparison of MBR performance is presented. Laboratory-scale submerged aerobic MBR (AMBR), anaerobic MBR (AnMBR), and attached-growth aerobic MBR (AtMBR) systems were evaluated for treating domestic wastewater under the same operating conditions. Long-term chemical oxygen demand (COD) and total organic carbon (TOC) monitoring showed greater than 80% removal in the three systems. The AnMBR system required three months of acclimation prior to steady operation, compared to one month for the aerobic systems. The AnMBR system exhibited a constant mixed liquor suspended solids concentration at an infinite solids retention time (i.e. no solids wasting), while the aerobic MBR systems produced approximately 0.25 g of biomass per gram of COD removed. This suggests a more economical solids management associated with the AnMBR system. Critical flux experiments were performed to evaluate fouling potential of the MBR systems. Results showed similar critical flux values between the AMBR and the AnMBR systems, while the AtMBR system showed relatively higher critical flux value. This result suggests a positive role of the attached-growth media in controlling membrane fouling in MBR systems. PMID:22049730

  15. Physiological activities associated with biofilm growth in attached and suspended growth bioreactors under aerobic and anaerobic conditions.

    PubMed

    Naz, Iffat; Seher, Shama; Perveen, Irum; Saroj, Devendra P; Ahmed, Safia

    2015-01-01

    This research work evaluated the biofilm succession on stone media and compared the biochemical changes of sludge in attached and suspended biological reactors operated under aerobic and anaerobic conditions. Stones incubated (30±2°C) with activated sludge showed a constant increase in biofilm weight up to the fifth and seventh week time under anaerobic and aerobic conditions, respectively, where after reduction (>80%) the most probable number index of pathogen indicators on ninth week was recorded. Reduction in parameters such as biological oxygen demand (BOD) (47.7%), chemical oxygen demand (COD, 41%), nitrites (60.2%), nitrates (105.5%) and phosphates (58.9%) and increase in dissolved oxygen (176.5%) of sludge were higher in aerobic attached growth reactors as compared with other settings. While, considerable reductions in these values were also observed (BOD, 53.8%; COD, 2.8%; nitrites, 28.6%; nitrates, 31.7%; phosphates, 41.4%) in the suspended growth system under anaerobic conditions. However, higher sulphate removal was observed in suspended (40.9% and 54.9%) as compared with biofilm reactors (28.2% and 29.3%). Six weeks biofilm on the stone media showed maximum physiological activities; thus, the operational conditions should be controlled to keep the biofilm structure similar to six-week-old biofilm, and can be used in fixed biofilm reactors for wastewater treatment. PMID:25609155

  16. Atypical defects resulting in growth hormone insensitivity.

    PubMed

    Wit, Jan M; de Luca, Francesco

    2016-06-01

    Besides four well-documented genetic causes of GH insensitivity (GHI) (GHR, STAT5B, IGF1, IGFALS defects), several other congenital and acquired conditions are associated with GHI. With respect to its anabolic actions, GH induces transcription of IGF1, IGFBP3 and IGFALS through a complex regulatory cascade including GH binding to its receptor (GHR), activation of JAK2 and phosphorylation of STAT5b, which then trafficks to the nucleus. GH also activates the MAPK and PI3K pathways. The synthesis of GHR can be reduced by estrogen deficiency or corticosteroid excess, and is possibly decreased in African pygmies. An increased degradation of GHRs because of overexpression of cytokine-inducible SH2-containing protein (CIS) was suggested for some children with idiopathic short stature. Effects on several downstream components of GH signaling were observed for FGF21, cytokines, sepsis, fever and chronic renal failure. In Noonan syndrome and other "rasopathies" the activation of the RAS-RAF-MAPK-ERK pathway leads to inhibition of the JAK/STAT pathway. In contrast, fibroblasts from tall patients with Sotos syndrome showed a downregulation of this axis. Experimental and clinical evidence suggests that the NF-κB pathway plays a role in GH signaling. In a patient with an IκBα mutation presenting with short stature, GHI, severe immune deficiency and other features, NF-κB nuclear transportation and STAT5 and PI3K expression and activity were reduced. A patient with a mosaic de novo duplication of 17q21-25 presented with several congenital anomalies, GHI and mild immunodeficiency. Studies in blood lymphocytes showed disturbed signaling of the CD28 pathway, involving NF-κB and related proteins. Functional studies on skin fibroblasts revealed that NF-κB activation, PI3K activity and STAT5 phosphorylation in response to GH were suppressed, while the sensitivity to GH in terms of MAPK phosphorylation was increased. The expression of one of the duplicated genes, PRKCA, was

  17. A TatABC-Type Tat Translocase Is Required for Unimpaired Aerobic Growth of Corynebacterium glutamicum ATCC13032

    PubMed Central

    Oertel, Dan; Schmitz, Sabrina; Freudl, Roland

    2015-01-01

    The twin-arginine translocation (Tat) system transports folded proteins across the cytoplasmic membrane of bacteria and the thylakoid membrane of plant chloroplasts. Escherichia coli and other Gram-negative bacteria possess a TatABC-type Tat translocase in which each of the three inner membrane proteins TatA, TatB, and TatC performs a mechanistically distinct function. In contrast, low-GC Gram-positive bacteria, such as Bacillus subtilis, use a TatAC-type minimal Tat translocase in which the TatB function is carried out by a bifunctional TatA. In high-GC Gram-positive Actinobacteria, such as Mycobacterium tuberculosis and Corynebacterium glutamicum, tatA, tatB, and tatC genes can be identified, suggesting that these organisms, just like E. coli, might use TatABC-type Tat translocases as well. However, since contrary to this view a previous study has suggested that C. glutamicum might in fact use a TatAC translocase with TatB only playing a minor role, we reexamined the requirement of TatB for Tat-dependent protein translocation in this microorganism. Under aerobic conditions, the misassembly of the Rieske iron-sulfur protein QcrA was identified as a major reason for the severe growth defect of Tat-defective C. glutamicum mutant strains. Furthermore, our results clearly show that TatB, besides TatA and TatC, is strictly required for unimpaired aerobic growth. In addition, TatB was also found to be essential for the secretion of a heterologous Tat-dependent model protein into the C. glutamicum culture supernatant. Together with our finding that expression of the C. glutamicum TatB in an E. coli ΔtatB mutant strain resulted in the formation of an active Tat translocase, our results clearly indicate that a TatABC translocase is used as the physiologically relevant functional unit for Tat-dependent protein translocation in C. glutamicum and, most likely, also in other TatB-containing Actinobacteria. PMID:25837592

  18. Aerobic training stimulates growth and promotes disease resistance in Atlantic salmon (Salmo salar).

    PubMed

    Castro, Vicente; Grisdale-Helland, Barbara; Helland, Ståle J; Kristensen, Torstein; Jørgensen, Sven Martin; Helgerud, Jan; Claireaux, Guy; Farrell, Anthony P; Krasnov, Aleksei; Takle, Harald

    2011-10-01

    Improving fish robustness is of utmost relevance to reducing fish losses in farming. Although not previously examined, we hypothesized that aerobic training, as shown for human studies, could strengthen disease resistance in Atlantic salmon (Salmo salar). Thus, we exercised salmon pre-smolts for 6 weeks at two different aerobic training regimes; a continuous intensity training (CT; 0.8bls(-1)) and an interval training (IT; 0.8bl s(-1) 16h and 1.0bl s(-1) 8h) and compared them with untrained controls (C; 0.05bl s(-1)). The effects of endurance training on disease resistance were evaluated using an IPN virus challenge test, while the cardiac immune modulatory effects were characterized by qPCR and microarray gene expression analyses. In addition, swimming performance and growth parameters were investigated. Survival after the IPN challenge was higher for IT (74%) fish than for either CT (64%) or C (61%) fish. While both CT and IT groups showed lower cardiac transcription levels of TNF-α, IL-1β and IL-6 prior to the IPN challenge test, IT fish showed the strongest regulation of genes involved in immune responses and other processes known to affect disease resistance. Both CT and IT regimes resulted in better growth compared with control fish, with CT fish developing a better swimming efficiency during training. Overall, interval aerobic training improved growth and increased robustness of Atlantic salmon, manifested by better disease resistance, which we found was associated with a modulation of relevant gene classes on the cardiac transcriptome. PMID:21726657

  19. Growth characteristics of freeze-tolerant baker's yeast Saccharomyces cerevisiae AFY in aerobic batch culture.

    PubMed

    Ji, Meng; Miao, Yelian; Chen, Jie Yu; You, Yebing; Liu, Feilong; Xu, Lin

    2016-01-01

    Saccharomyces cerevisiae AFY is a novel baker's yeast strain with strong freeze-tolerance, and can be used for frozen-dough processing. The present study armed to clarify the growth characteristics of the yeast AFY. Aerobic batch culture experiments of yeast AFY were carried out using media with various initial glucose concentrations, and the culture process was analyzed kinetically. The growth of the yeast AFY exhibited a diauxic pattern with the first growth stage consuming glucose and the second growth stage consuming ethanol. The cell yield decreased with increasing initial glucose concentration in the first growth stage, and also decreased with increasing initial ethanol concentration in the second growth stage. In the initial glucose concentration range of 5.0-40.0 g/L, the simultaneous equations of Monod equation, Luedeking-Piret equation and pseudo-Luedeking-Piret equation could be used to describe the concentrations of cell, ethanol and glucose in either of the two exponential growth phases. At the initial glucose concentrations of 5.0, 10.0 and 40.0 g/L, the first exponential growth phase had a maximal specific cell growth rate of 0.52, 0.98 and 0.99 h(-1), while the second exponential growth phase had a maximal specific cell growth rate of 0.11, 0.06 and 0.07 h(-1), respectively. It was indicated that the efficiency of the yeast production could be improved by reducing the ethanol production in the first growth stage. PMID:27186467

  20. Correlation of growth of aerobic blood cultures in hypertonic broth with antibiotic therapy.

    PubMed Central

    Eng, J; Maeland, A

    1982-01-01

    The aim of this study was to elucidate the mechanisms by which sucrose improves growth in a hypertonic medium for isolating aerobes from blood. Clinical blood cultures were made routinely in duplicate in plain broth consisting of brain heart infusion broth with sodium polyanetholesulfonate, gelatin, and penicillinase and the same broth with 20% sucrose added. The growth patterns of Staphylococcus aureus and Enterobacteriaceae from plain and from hypertonic broth were correlated with the presence or absence of antimicrobial therapy in patients when the blood cultures were collected. In S. aureus bacteremias, 58.7% of the positive cultures collected during treatment of patients with beta-lactam antibiotics showed earlier growth or growth only in hypertonic broth, compared with 16.7% of the cultures taken during treatment with other antimicrobial agents (P less than 0.05) and 17.6% of the cultures made in antibiotic-free intervals (P less than 0.01). In the group of cultures yielding growth of Enterobacteriaceae, growth occurred earlier or solely in hypertonic broth in 28.9% of the cultures taken during treatment with beta-lactam antibiotics, compared with 15.7% of the cultures taken during treatment with other antimicrobial agents and 21.6% of the cultures collected in antibiotic-free intervals (differences not statistically significant). It is concluded that treatment with beta-lactam antibiotics is an important reason for the improved growth of S. aureus from hypertonic broth, but other factors are also involved. PMID:7153339

  1. Growth defects in thick ion-plated coatings

    NASA Technical Reports Server (NTRS)

    Spalvins, T.

    1975-01-01

    Industrial ion plating conditions were selected to deposit metallic coatings such as copper, gold, and chromium 2 micrometer thick on metal and glass substrates. The surface finishes of 304 stainless steel, copper, and brass were utilized with mechanically and electrolytically polished surfaces. Nodular growth occurred in these coatings during ion plating as revealed by scanning electron microscopy. Surface irregularities such as scratches, steps, ledges, and so forth are responsible for outward growth, the typical cone type, whereas surface contaminants and loosely settled foreign particles are responsible for lateral growth; namely, the extreme localized surface outgrowths. These defect crystallographic features create porosity in the coatings when subjected to stresses and strains.

  2. Aerobic growth of Anoxybacillus pushchinoensis K1(T): emended descriptions of A. pushchinoensis and the genus Anoxybacillus

    NASA Technical Reports Server (NTRS)

    Pikuta, Elena; Cleland, David; Tang, Jane

    2003-01-01

    In this work, corrections are made to the descriptions of the species Anoxybacillus pushchinoensis corrig. and the genus ANOXYBACILLUS: Experiments to determine the relationship of A. pushchinoensis K1(T) to oxygen showed that it was capable of aerobic growth, but preferred to grow anaerobically. During aerobic growth, the redox indicator resazurin was reduced as a result of hydrogen gas production. The facultatively anaerobic nature of K1(T) was ascertained by cultivation in aerobic liquid medium, where growth began at the bottom of the tube. The anaerobic nature of K1(T) was also indicated by a negative catalase reaction. This work is submitted to correct the description of the species A. pushchinoensis from obligate anaerobe to aerotolerant anaerobe and to emend the description of the genus Anoxybacillus from obligate anaerobes or facultative anaerobes to aerotolerant anaerobes or facultative anaerobes.

  3. Influence of Partial Denitrification and Mixotrophic Growth of NOB on Microbial Distribution in Aerobic Granular Sludge.

    PubMed

    Winkler, Mari-K H; Le, Quan H; Volcke, Eveline I P

    2015-09-15

    In aerobic granular sludge (AGS), the growth of nitrite oxidizing bacteria (NOB) can be uncoupled from the nitrite supply of ammonia oxidizing bacteria (AOB). Besides, unlike for conventional activated sludge, Nitrobacter was found to be the dominant NOB and not Nitrospira. To explain these experimental observations, two possible pathways have been put forward in literature. The first one involves the availability of additional nitrite from partial denitrification (nitrite-loop) and the second one consists of mixotrophic growth of Nitrobacter in the presence of acetate (ping-pong). In this contribution, mathematical models were set up to assess the possibility of these pathways to explain the reported observations. Simulation results revealed that both pathways influenced the nitrifier distribution in the granules. The nitrite-loop pathway led to an elevated NOB/AOB ratio, while mixotrophic growth of Nitrobacter guaranteed their predominance among the NOB population. Besides, mixotrophic growth of Nitrobacter could lead to NO emission from AGS. An increasing temperature and/or a decreasing oxygen concentration led to an elevated NOB/AOB ratio and increased NO emissions. PMID:26248168

  4. Characterization of defect growth structures in ion plated films by scanning electron microscopy

    NASA Technical Reports Server (NTRS)

    Spalvins, T.

    1979-01-01

    Gold and copper films (0.2-2 micron thick) are ion plated on very smooth stainless steel 304 and mica surfaces. The deposited films are examined by SEM to identify the morphological growth of defects. Three types of coating defects are distinguished: nodular growth, abnormal or runaway growth, and spits. The potential nucleation sites for defect growth are analyzed to determine the cause of defect formation. It is found that nuclear growth is due to inherent surface microdefects, abnormal or runaway growth is due to external surface inclusions, and spits are due to nonuniform evaporation and ejection of droplets. All these defects have adverse effects on the coatings.

  5. Aerobic Degradation of Trichloroethylene by Co-Metabolism Using Phenol and Gasoline as Growth Substrates

    PubMed Central

    Li, Yan; Li, Bing; Wang, Cui-Ping; Fan, Jun-Zhao; Sun, Hong-Wen

    2014-01-01

    Trichloroethylene (TCE) is a common groundwater contaminant of toxic and carcinogenic concern. Aerobic co-metabolic processes are the predominant pathways for TCE complete degradation. In this study, Pseudomonas fluorescens was studied as the active microorganism to degrade TCE under aerobic condition by co-metabolic degradation using phenol and gasoline as growth substrates. Operating conditions influencing TCE degradation efficiency were optimized. TCE co-metabolic degradation rate reached the maximum of 80% under the optimized conditions of degradation time of 3 days, initial OD600 of microorganism culture of 0.14 (1.26 × 107 cell/mL), initial phenol concentration of 100 mg/L, initial TCE concentration of 0.1 mg/L, pH of 6.0, and salinity of 0.1%. The modified transformation capacity and transformation yield were 20 μg (TCE)/mg (biomass) and 5.1 μg (TCE)/mg (phenol), respectively. Addition of nutrient broth promoted TCE degradation with phenol as growth substrate. It was revealed that catechol 1,2-dioxygenase played an important role in TCE co-metabolism. The dechlorination of TCE was complete, and less chlorinated products were not detected at the end of the experiment. TCE could also be co-metabolized in the presence of gasoline; however, the degradation rate was not high (28%). When phenol was introduced into the system of TCE and gasoline, TCE and gasoline could be removed at substantial rates (up to 59% and 69%, respectively). This study provides a promising approach for the removal of combined pollution of TCE and gasoline. PMID:24857922

  6. Aerobic degradation of trichloroethylene by co-metabolism using phenol and gasoline as growth substrates.

    PubMed

    Li, Yan; Li, Bing; Wang, Cui-Ping; Fan, Jun-Zhao; Sun, Hong-Wen

    2014-01-01

    Trichloroethylene (TCE) is a common groundwater contaminant of toxic and carcinogenic concern. Aerobic co-metabolic processes are the predominant pathways for TCE complete degradation. In this study, Pseudomonas fluorescens was studied as the active microorganism to degrade TCE under aerobic condition by co-metabolic degradation using phenol and gasoline as growth substrates. Operating conditions influencing TCE degradation efficiency were optimized. TCE co-metabolic degradation rate reached the maximum of 80% under the optimized conditions of degradation time of 3 days, initial OD600 of microorganism culture of 0.14 (1.26×10⁷ cell/mL), initial phenol concentration of 100 mg/L, initial TCE concentration of 0.1 mg/L, pH of 6.0, and salinity of 0.1%. The modified transformation capacity and transformation yield were 20 μg (TCE)/mg (biomass) and 5.1 μg (TCE)/mg (phenol), respectively. Addition of nutrient broth promoted TCE degradation with phenol as growth substrate. It was revealed that catechol 1,2-dioxygenase played an important role in TCE co-metabolism. The dechlorination of TCE was complete, and less chlorinated products were not detected at the end of the experiment. TCE could also be co-metabolized in the presence of gasoline; however, the degradation rate was not high (28%). When phenol was introduced into the system of TCE and gasoline, TCE and gasoline could be removed at substantial rates (up to 59% and 69%, respectively). This study provides a promising approach for the removal of combined pollution of TCE and gasoline. PMID:24857922

  7. Determination of growth value thresholds for BACTEC PLUS aerobic blood culture vials.

    PubMed

    McGowan, J E; Metchock, B G

    1992-04-01

    Growth value thresholds used to identify positive blood culture vials can be defined by users for each BACTEC NR-660 bacteremia detection instrument. Growth values were compared with the recovery of organisms from vials flagged as positive during the testing of 3.056 high-volume vials containing aerobic (BACTEC PLUS 26) medium over a 2-month period. Results showed that optimal threshold values for our use of these vials varied from those recommended by the manufacturer; if the thresholds defined from these data had been used during the study period, total vials flagged as positive from which no organisms were recovered (false alarms) would have been reduced from 181 (5.9/100 vials tested) to 71 (2.3/100 vials tested), with a minimal decrease in the identification of vials containing usual or occasional pathogens (hits). Adjustments of growth value thresholds by the individual user can make the use of BACTEC instruments more efficient by decreasing further processing of vials from which no organisms are recovered. PMID:1572964

  8. Growth and defect chemistry of amorphous hydrogenated silicon

    NASA Astrophysics Data System (ADS)

    Scott, Bruce A.; Reimer, Jeffrey A.; Longeway, Paul A.

    1983-12-01

    Magnetic resonance (NMR,EPR) and infrared studies are presented of amorphous hydrogenated silicon (a-Si:H) films prepared by homogeneous chemical vapor deposition (HOMOCVD) and rf plasma decomposition using silane and disilane. Hydrogen incorporation occurs with a small activation energy (˜0.06 eV) for all films, while the barrier for changes in spin defect density is almost an order of magnitude larger and comparable to that measured in defect annealing studies. Films deposited by rf(Si2H6) plasma exhibit the greatest hydrogen contents, followed by HOMOCVD and rf(SiH4) plasma material. NMR measurements suggest that HOMOCVD films are less disordered than plasma-deposited a-Si:H. Previous work and recent kinetic studies of plasma and thermal environments are extensively analyzed, along with thermodynamic and kinetic data, to determine a a-Si:H growth mechanisms most consistent with the experimental results. The model presented to explain compositional and defect changes with substrate temperature emphasizes plasma deposition by monoradical precursors and HOMOCVD growth by diradicals, resulting initially in a similar surface-bound intermediate in all cases. Plasma growth from Si2H6 involves the surface attachment of longer radical chains, compared to SiH4, while oligomeric diradicals could be present in HOMOCVD. The possibility that reactions at the hot reactor wall, as well as in the gas, create monoradicals in HOMOCVD is also explored in detail. Finally, film dehydrogenation and crosslinking reactions are examined, and experiments proposed to determine the channels most relevant for each deposition environment.

  9. Growth of Aerobic Ripening Bacteria at the Cheese Surface Is Limited by the Availability of Iron

    PubMed Central

    Back, Alexandre; Irlinger, Françoise

    2012-01-01

    The microflora on the surface of smear-ripened cheeses is composed of various species of bacteria and yeasts that contribute to the production of the desired organoleptic properties. The objective of the present study was to show that iron availability is a limiting factor in the growth of typical aerobic ripening bacteria in cheese. For that purpose, we investigated the effect of iron or siderophore addition in model cheeses that were coinoculated with a yeast and a ripening bacterium. Both iron and the siderophore desferrioxamine B stimulated the growth of ripening bacteria belonging to the genera Arthrobacter, Corynebacterium, and Brevibacterium. The extent of stimulation was strain dependent, and generally, the effect of desferrioxamine B was greater than that of iron. Measurements of the expression of genes related to the metabolism of iron by Arthrobacter arilaitensis Re117 by real-time reverse transcription-PCR showed that these genes were transcribed during growth in cheese. The addition of desferrioxamine B increased the expression of two genes encoding iron-siderophore ABC transport binding proteins. The addition of iron decreased the expression of siderophore biosynthesis genes and of part of the genes encoding iron-siderophore ABC transport components. It was concluded that iron availability is a limiting factor in the growth of typical cheese surface bacteria. The selection of strains with efficient iron acquisition systems may be useful for the development of defined-strain surface cultures. Furthermore, the importance of iron metabolism in the microbial ecology of cheeses should be investigated since it may result in positive or negative microbial interactions. PMID:22367081

  10. Mathematical model for the aerobic growth of saccharomyces cerevisiae with a saturated respiratory capacity

    SciTech Connect

    Barford, J.P.; Hall, R.J.

    1981-08-01

    A mathematical model for the aerobic growth of Saccharomyces cerevisiae in both batch and continuous culture is described. It was based on the experimental observation that the respiratory capacity of this organism may become saturated and exhibit a maximum specific oxygen uptake rate after suitable adaptation. This experimental observation led to the possibility that transport into and out of the mitochondrion was of major importance in the overall metabolism of S. cerevisiae and was subject to long-term adaptation. Consistent with this observation a distributed model was proposed which, as its basis, assumed the control of respiration and fermentation to be the result of saturation of respiration without any specific repression or inhibition of the uptake rates of other substrates. No other regulation of fermentation and respiration was assumed. The model provided a suitable structure allowing precise quantification of the changes in rate and stoichiometry of energy production. The model clearly indicated that growth under the wide range of experimental conditions reported could not be predicted using constant values for the maximum specific respiratory rate or constant values of Yatp (g biomass/mol ATP) and PO ratio of (mol ATP/atom oxygen). The causes of the variation in the respiratory rate were not determined and it was concluded that a more detailed analysis (reported subsequently) was required. The variation of Y atp and PO ratio with specific growth rate implied that the efficiency of ATP generation or ATP utilization decreased with increasing specific growth rate. It was concluded that it was not possible to quantify the individual effect of Yatp and PO ratio until independent means for their reliable estimation is available. (Refs. 84).

  11. Effects of aerobic exercise on ectopic lipids in patients with growth hormone deficiency before and after growth hormone replacement therapy

    PubMed Central

    Christ, Emanuel R.; Egger, Andrea; Allemann, Sabin; Buehler, Tania; Kreis, Roland; Boesch, Chris

    2016-01-01

    Growth hormone replacement therapy (GHRT) increases exercise capacity and insulin resistance while it decreases fat mass in growth hormone-deficient patients (GHD). Ectopic lipids (intramyocellular (IMCL) and intrahepatocellular lipids (IHCL) are related to insulin resistance. The effect of GHRT on ectopic lipids is unknown. It is hypothesized that exercise-induced utilization of ectopic lipids is significantly decreased in GHD patients and normalized by GHRT. GHD (4 females, 6 males) and age/gender/waist-matched control subjects (CS) were studied. VO2max was assessed on a treadmill and insulin sensitivity determined by a two-step hyperinsulinaemic-euglycaemic clamp. Visceral (VAT) and subcutaneous (SAT) fat were quantified by MR-imaging. IHCL and IMCL were measured before and after a 2 h exercise at 50–60% of VO2max using MR-spectroscopy (∆IMCL, ∆IHCL). Identical investigations were performed after 6 months of GHRT. VO2max was similar in GHD and CS and significantly increased after GHRT; GHRT significantly decreased SAT and VAT. 2 h-exercise resulted in a decrease in IMCL (significant in CS and GHRT) and a significant increase in IHCL in CS and GHD pre and post GHRT. GHRT didn’t significantly impact on ∆IMCL and ∆IHCL. We conclude that aerobic exercise affects ectopic lipids in patients and controls. GHRT increases exercise capacity without influencing ectopic lipids. PMID:26792091

  12. Production of wax esters during aerobic growth of marine bacteria on isoprenoid compounds

    PubMed

    Rontani; Bonin; Volkman

    1999-01-01

    This paper describes the production of isoprenoid wax esters during the aerobic degradation of 6,10,14-trimethylpentadecan-2-one and phytol by four bacteria (Acinetobacter sp. strain PHY9, Pseudomonas nautica [IP85/617], Marinobacter sp. strain CAB [DSMZ 11874], and Marinobacter hydrocarbonoclasticus [ATCC 49840]) isolated from the marine environment. Different pathways are proposed to explain the formation of these compounds. In the case of 6,10, 14-trimethylpentadecan-2-one, these esters result from the condensation of some acidic and alcoholic metabolites produced during the biodegradation, while phytol constitutes the alcohol moiety of most of the esters produced during growth on this isoprenoid alcohol. The amount of these esters formed increased considerably in N-limited cultures, in which the ammonium concentration corresponds to conditions often found in marine sediments. This suggests that the bacterial formation of isoprenoid wax esters might be favored in such environments. Although conflicting evidence exists regarding the stability of these esters in sediments, it seems likely that, under some conditions, bacterial esterification can enhance the preservation potential of labile compounds such as phytol. PMID:9872783

  13. Atomic and electronic structure of twin growth defects in magnetite

    PubMed Central

    Gilks, Daniel; Nedelkoski, Zlatko; Lari, Leonardo; Kuerbanjiang, Balati; Matsuzaki, Kosuke; Susaki, Tomofumi; Kepaptsoglou, Demie; Ramasse, Quentin; Evans, Richard; McKenna, Keith; Lazarov, Vlado K.

    2016-01-01

    We report the existence of a stable twin defect in Fe3O4 thin films. By using aberration corrected scanning transmission electron microscopy and spectroscopy the atomic structure of the twin boundary has been determined. The boundary is confined to the (111) growth plane and it is non-stoichiometric due to a missing Fe octahedral plane. By first principles calculations we show that the local atomic structural configuration of the twin boundary does not change the nature of the superexchange interactions between the two Fe sublattices across the twin grain boundary. Besides decreasing the half-metallic band gap at the boundary the altered atomic stacking at the boundary does not change the overall ferromagnetic (FM) coupling between the grains. PMID:26876049

  14. Activity and growth of anammox biomass on aerobically pre-treated municipal wastewater.

    PubMed

    Laureni, Michele; Weissbrodt, David G; Szivák, Ilona; Robin, Orlane; Nielsen, Jeppe Lund; Morgenroth, Eberhard; Joss, Adriano

    2015-09-01

    Direct treatment of municipal wastewater (MWW) based on anaerobic ammonium oxidizing (anammox) bacteria holds promise to turn the energy balance of wastewater treatment neutral or even positive. Currently, anammox processes are successfully implemented at full scale for the treatment of high-strength wastewaters, whereas the possibility of their mainstream application still needs to be confirmed. In this study, the growth of anammox organisms on aerobically pre-treated municipal wastewater (MWW(pre-treated)), amended with nitrite, was proven in three parallel reactors. The reactors were operated at total N concentrations in the range 5-20 mg(N)∙L(-1), as expected for MWW. Anammox activities up to 465 mg(N)∙L(-1)∙d(-1) were reached at 29 °C, with minimum doubling times of 18 d. Lowering the temperature to 12.5 °C resulted in a marked decrease in activity to 46 mg(N)∙L(-1)∙d(-1) (79 days doubling time), still in a reasonable range for autotrophic nitrogen removal from MWW. During the experiment, the biomass evolved from a suspended growth inoculum to a hybrid system with suspended flocs and wall-attached biofilm. At the same time, MWW(pre-treated) had a direct impact on process performance. Changing the influent from synthetic medium to MWW(pre-treated) resulted in a two-month delay in net anammox growth and a two to three-fold increase in the estimated doubling times of the anammox organisms. Interestingly, anammox remained the primary nitrogen consumption route, and high-throughput 16S rRNA gene-targeted amplicon sequencing analyses revealed that the shift in performance was not associated with a shift in dominant anammox bacteria ("Candidatus Brocadia fulgida"). Furthermore, only limited heterotrophic denitrification was observed in the presence of easily biodegradable organics (acetate, glucose). The observed delays in net anammox growth were thus ascribed to the acclimatization of the initial anammox population or/and the development of a side

  15. Proteasome dysfunction induces muscle growth defects and protein aggregation

    PubMed Central

    Kitajima, Yasuo; Tashiro, Yoshitaka; Suzuki, Naoki; Warita, Hitoshi; Kato, Masaaki; Tateyama, Maki; Ando, Risa; Izumi, Rumiko; Yamazaki, Maya; Abe, Manabu; Sakimura, Kenji; Ito, Hidefumi; Urushitani, Makoto; Nagatomi, Ryoichi; Takahashi, Ryosuke; Aoki, Masashi

    2014-01-01

    ABSTRACT The ubiquitin–proteasome and autophagy–lysosome pathways are the two major routes of protein and organelle clearance. The role of the proteasome pathway in mammalian muscle has not been examined in vivo. In this study, we report that the muscle-specific deletion of a crucial proteasomal gene, Rpt3 (also known as Psmc4), resulted in profound muscle growth defects and a decrease in force production in mice. Specifically, developing muscles in conditional Rpt3-knockout animals showed dysregulated proteasomal activity. The autophagy pathway was upregulated, but the process of autophagosome formation was impaired. A microscopic analysis revealed the accumulation of basophilic inclusions and disorganization of the sarcomeres in young adult mice. Our results suggest that appropriate proteasomal activity is important for muscle growth and for maintaining myofiber integrity in collaboration with autophagy pathways. The deletion of a component of the proteasome complex contributed to myofiber degeneration and weakness in muscle disorders that are characterized by the accumulation of abnormal inclusions. PMID:25380823

  16. Interface stability and defect formation during crystal growth

    SciTech Connect

    Fabietti, L.M.R.

    1991-01-08

    Unidirectional solidification experiments have been carried out in organic crystals with the aim of improving our knowledge on the effects of constraints on the interface morphology and to increase our understanding of the growth of anisotropic materials. The experimental information shows that lateral constraints such as a sharp change in the cross-sectional area in the solid liquid interface path, can produce important changes in the microstructure if the interface morphology is planar, cellular or dendritic. The study of anisotropic materials cover several topics. It is first shown that slight anisotropy does not influence the dendrite tip selection criterion. This conclusion is obtained from the analysis of the relationship between tip radius and velocity for dendrites growing under the steady state condition for two different materials, CBr{sub 4} and C{sub 2}Cl{sub 6}, which have different surface energy anisotropy values. The values of the dendrite operating parameters {sigma}* are compared with the predictions of the solvability theory and the morphological stability theory. The experiments show better agreement with the latter theory. Critical experiments have been designed and carried out to find the response functions which determine the composition and temperature of the interface as a function of velocity in faceted materials. The experiments, carried out in Napthalene-Camphor system, indicate a strong temperature dependence of the planar interface growth which can be correlated with the step growth mechanism. Experiments on the interface instability show an important dependence on the crystallographic orientation. Unidirectional solidification experiments in zone refined Napthalene confined in very thin cells (gap size {le} 50 {mu}m) have proven to be a good method to study the defect production at the solid liquid interface. 118 refs., 90 figs., 5 tabs.

  17. Growth, defect structure, and THz application of stoichiometric lithium niobate

    NASA Astrophysics Data System (ADS)

    Lengyel, K.; Péter, Á.; Kovács, L.; Corradi, G.; Pálfalvi, L.; Hebling, J.; Unferdorben, M.; Dravecz, G.; Hajdara, I.; Szaller, Zs.; Polgár, K.

    2015-12-01

    Owing to the extraordinary richness of its physical properties, congruent lithium niobate has attracted multidecade-long interest both for fundamental science and applications. The combination of ferro-, pyro-, and piezoelectric properties with large electro-optic, acousto-optic, and photoelastic coefficients as well as the strong photorefractive and photovoltaic effects offers a great potential for applications in modern optics. To provide powerful optical components in high energy laser applications, tailoring of key material parameters, especially stoichiometry, is required. This paper reviews the state of the art of growing large stoichiometric LiNbO3 (sLN) crystals, in particular, the defect engineering of pure and doped sLN with emphasis on optical damage resistant (ODR) dopants (e.g., Mg, Zn, In, Sc, Hf, Zr, Sn). The discussion is focused on crystals grown by the high temperature top seeded solution growth (HTTSSG) technique using alkali oxide fluxing agents. Based on high-temperature phase equilibria studies of the Li2O-Nb2O5-X2O ternary systems (X = Na, K, Rb, Cs), the impact of alkali homologue additives on the stoichiometry of the lithium niobate phase will be analyzed, together with a summary of the ultraviolet, infrared, and far-infrared absorption spectroscopic methods developed to characterize the composition of the crystals. It will be shown that using HTTSSG from K2O containing flux, crystals closest to the stoichiometric composition can be grown characterized by a UV-edge position of at about 302 nm and a single narrow hydroxyl band in the IR with a linewidth of less than 3 cm-1 at 300 K. The threshold concentrations for ODR dopants depend on crystal stoichiometry and the valence of the dopants; Raman spectra, hydroxyl vibration spectra, and Z-scan measurements prove to be useful to distinguish crystals below and above the photorefractive threshold. Crystals just above the threshold are preferred for most nonlinear optical applications apart

  18. Characterization of defect growth structure in ion plated films by scanning electron microscopy

    NASA Technical Reports Server (NTRS)

    Spalvins, T.

    1979-01-01

    Copper and gold films (0.2 to 2 microns) were ion plated onto polished 304-stainless-steel surfaces. These coatings were examined by scanning electron microscopy for coating growth defects. Three types of defects were distinguished: nodular growth, abnormal or runaway growth, and spits. The cause and origin for each type of defect was traced. Nodular growth is primarily due to inherent substrate microdefects, abnormal or runaway growth is due to external surface inclusions, and spits are due to nonuniform evaporation. All these defects have adverse effects on the coatings. They induce stresses and produce porosity in the coatings and thus weaken their mechanical properties. Friction and wear characteristics are affected by coating defects, since the large nodules are pulled out and additional wear debris is generated.

  19. The effect of aerobic exercise and starvation on growth performance and postprandial metabolic response in juvenile southern catfish (Silurus meridionalis).

    PubMed

    Li, Xiu-Ming; Liu, Li; Yuan, Jian-Ming; Xiao, Yuan-Yuan; Fu, Shi-Jian; Zhang, Yao-Guang

    2016-03-01

    To investigate the effects of aerobic exercise and starvation on growth performance, postprandial metabolic response and their interaction in a sedentary fish species, either satiation-fed or starved juvenile southern catfish (Silurus meridionalis) were exercised at 25 °C under three water velocities, i.e., nearly still water (control), 1 body length (bl) s(-1) and 2 bl s(-1), for eight weeks. Then, the feed intake (FI), food conversion efficiency (FCE), specific growth rate (SGR), morphological parameters, resting ṀO2 (ṀO2rest) and postprandial ṀO2 responses of the experimental fish were measured. Exercise at a low velocity (1 bl s(-1)) showed no effect on any growth performance parameter, whereas exercise at a high velocity (2 bl s(-1)) exhibited higher FI but similar SGR due to the extra energy expenditure from swimming and consequent decreased FCE. Starvation led to a significant body mass loss, whereas the effect intensified in both exercise groups. Exercise resulted in improved cardio-respiratory capacity, as indicated by increased gill and heart indexes, whereas it exhibited no effect on resting and postprandial metabolism in S. meridionalis. The starved fish displayed significantly larger heart, gill and digestive tract indexes compared with the feeding fish, suggesting selective maintenance of cardio-respiratory and digestive function in this fish species during starvation. However, starved fish still exhibited impaired digestive performance, as evidenced by the prolonged duration and low postprandial metabolic increase, and this effect was further exacerbated in both the 1 and 2 bl s(-1) exercise groups. These data suggest the following: (1) aerobic exercise produced no improvement in growth performance but may have led to the impairment of growth under insufficient food conditions; (2) the mass of different organs and tissues responded differently to aerobic exercise and starvation due to the different physiological roles they play; and (3

  20. Growth dynamics of specific spoilage organisms and associated spoilage biomarkers in chicken breast stored aerobically

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was performed to identify and quantify selected volatile spoilage biomarkers in a headspace over chicken breast using solid phase microextraction (SPME) combined with gas chromatography-mass spectrometry-flame ionization detectors (GC-MS/FID). The chicken breast samples were aerobically s...

  1. Growth, defect structure, and THz application of stoichiometric lithium niobate

    SciTech Connect

    Lengyel, K.; Péter, Á.; Kovács, L.; Corradi, G.; Dravecz, G.; Hajdara, I.; Szaller, Zs.; Polgár, K.; Pálfalvi, L.; Unferdorben, M.; Hebling, J.

    2015-12-15

    Owing to the extraordinary richness of its physical properties, congruent lithium niobate has attracted multidecade-long interest both for fundamental science and applications. The combination of ferro-, pyro-, and piezoelectric properties with large electro-optic, acousto-optic, and photoelastic coefficients as well as the strong photorefractive and photovoltaic effects offers a great potential for applications in modern optics. To provide powerful optical components in high energy laser applications, tailoring of key material parameters, especially stoichiometry, is required. This paper reviews the state of the art of growing large stoichiometric LiNbO{sub 3} (sLN) crystals, in particular, the defect engineering of pure and doped sLN with emphasis on optical damage resistant (ODR) dopants (e.g., Mg, Zn, In, Sc, Hf, Zr, Sn). The discussion is focused on crystals grown by the high temperature top seeded solution growth (HTTSSG) technique using alkali oxide fluxing agents. Based on high-temperature phase equilibria studies of the Li{sub 2}O–Nb{sub 2}O{sub 5}–X{sub 2}O ternary systems (X = Na, K, Rb, Cs), the impact of alkali homologue additives on the stoichiometry of the lithium niobate phase will be analyzed, together with a summary of the ultraviolet, infrared, and far-infrared absorption spectroscopic methods developed to characterize the composition of the crystals. It will be shown that using HTTSSG from K{sub 2}O containing flux, crystals closest to the stoichiometric composition can be grown characterized by a UV-edge position of at about 302 nm and a single narrow hydroxyl band in the IR with a linewidth of less than 3 cm{sup −1} at 300 K. The threshold concentrations for ODR dopants depend on crystal stoichiometry and the valence of the dopants; Raman spectra, hydroxyl vibration spectra, and Z-scan measurements prove to be useful to distinguish crystals below and above the photorefractive threshold. Crystals just above the threshold are

  2. Growth parameters of escherichia coli O157:H7, salmonella and listeria monocytogenes and aerobic mesophilic bacteria of apple cider amended with nisin-EDTA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of nisin (0 or 300 IU), Ethylenediamine Tetraacetic Acid (EDTA, 20 mM) and (nisin 300 IU+ EDTA 20 mM) on growth parameters; including lag period (LP) and growth rate (GR) of Escherichia coli O157:H7, L. monocytogenes and Salmonella spp. in the presence or absence of aerobic mesophilic bac...

  3. Reduced expression of cytochrome oxidases largely explains cAMP inhibition of aerobic growth in Shewanella oneidensis

    PubMed Central

    Yin, Jianhua; Meng, Qiu; Fu, Huihui; Gao, Haichun

    2016-01-01

    Inhibition of bacterial growth under aerobic conditions by elevated levels of cyclic adenosine 3′,5′-monophosphate (cAMP), first revealed more than 50 years ago, was attributed to accumulation of toxic methylglyoxal (MG). Here, we report a Crp-dependent mechanism rather than MG accumulation that accounts for the phenotype in Shewanella oneidensis, an emerging research model for the bacterial physiology. We show that a similar phenotype can be obtained by removing CpdA, a cAMP phosphodiesterase that appears more effective than its Escherichia coli counterpart. Although production of heme c and cytochromes c is correlated well with cAMP levels, neither is sufficient for the retarded growth. Quantities of overall cytochromes c increased substantially in the presence of elevated cAMP, a phenomenon resembling cells respiring on non-oxygen electron acceptors. In contrast, transcription of Crp-dependent genes encoding both cytochromes bd and cbb3 oxidases is substantially repressed under the same condition. Overall, our results suggest that cAMP of elevated levels drives cells into a low-energetic status, under which aerobic respiration is inhibited. PMID:27076065

  4. The Peroxiredoxin Tpx1 Is Essential as a H2O2 Scavenger during Aerobic Growth in Fission Yeast

    PubMed Central

    Jara, Mónica; Vivancos, Ana P.; Calvo, Isabel A.; Moldón, Alberto; Sansó, Miriam

    2007-01-01

    Peroxiredoxins are known to interact with hydrogen peroxide (H2O2) and to participate in oxidant scavenging, redox signal transduction, and heat-shock responses. The two-cysteine peroxiredoxin Tpx1 of Schizosaccharomyces pombe has been characterized as the H2O2 sensor that transduces the redox signal to the transcription factor Pap1. Here, we show that Tpx1 is essential for aerobic, but not anaerobic, growth. We demonstrate that Tpx1 has an exquisite sensitivity for its substrate, which explains its participation in maintaining low steady-state levels of H2O2. We also show in vitro and in vivo that inactivation of Tpx1 by oxidation of its catalytic cysteine to a sulfinic acid is always preceded by a sulfinic acid form in a covalently linked dimer, which may be important for understanding the kinetics of Tpx1 inactivation. Furthermore, we provide evidence that a strain expressing Tpx1.C169S, lacking the resolving cysteine, can sustain aerobic growth, and we show that small reductants can modulate the activity of the mutant protein in vitro, probably by supplying a thiol group to substitute for cysteine 169. PMID:17409354

  5. Method of controlling defect orientation in silicon crystal ribbon growth

    NASA Technical Reports Server (NTRS)

    Leipold, M. H. (Inventor)

    1978-01-01

    The orientation of twinning and other effects in silicon crystal ribbon growth is controlled by use of a starting seed crystal having a specific (110) crystallographic plane and (112) crystallographic growth direction.

  6. The preferential growth of branched GDGT source microorganisms under aerobic conditions in peat revealed by stable isotope probing experiments

    NASA Astrophysics Data System (ADS)

    Huguet, Arnaud; Meador, Travis B.; Laggoun-Défarge, Fatima; Könneke, Martin; Derenne, Sylvie; Hinrichs, Kai-Uwe

    2016-04-01

    Branched glycerol dialkyl glycerol tetraether (brGDGTs) membrane lipids are widely distributed in aquatic and terrestrial environments and are being increasingly used as temperature proxies. Nevertheless, little is known regarding the microorganisms that produce these lipids, which are found in especially high abundance in the anaerobic horizons of peat bogs. We initiated stable isotope probing incubations of peat samples from a Sphagnum-dominated peatland (Jura Mountains, France) to measure the incorporation of (D)-D2O and 13C-labeled dissolved inorganic carbon (DIC) into brGDGTs, and thus gauge the activity, growth, and turnover times of their source organisms. Peat samples were collected from two adjacent sites with contrasting humidity levels (hereafter called "fen" and "bog" sites). For each site, samples from the surficial aerobic layer (acrotelm) and deeper anaerobic layer (catotelm) were collected and were incubated under both anaerobic and aerobic conditions for the acrotelm samples and only anaerobic conditions for the catotelm. The incubations were performed at 12 ° C, consistent with the mean summer air temperature at the sampling site. After two months of incubation, there was no incorporation of 13C label in brGDGTs for samples incubated under either aerobic or anaerobic conditions, showing that brGDGT-producing bacteria are heterotrophic microorganisms, as previously observed in organo-mineral soils (Weijers et al., 2011). Similarly, little to no deuterium incorporation was observed for brGDGTs isolated from anaerobically-incubated deep samples. In contrast, in the aerobic incubations of acrotelm samples from bog and fen, the weighted average δD of brGDGT core lipids (CLs) increased by up to 3332‰ and 933‰ after two months, respectively, indicating that fresh brGDGT CLs were biosynthesized at the peat surface. D incorporation into brGDGT CLs converted to production rates ranging from 30-106 ng cm‑3y‑1 in the aerobic acrotelm from bog and

  7. Chemolithotrophic growth of the aerobic hyperthermophilic bacterium Thermocrinis ruber OC 14/7/2 on monothioarsenate and arsenite.

    PubMed

    Härtig, Cornelia; Lohmayer, Regina; Kolb, Steffen; Horn, Marcus A; Inskeep, William P; Planer-Friedrich, Britta

    2014-12-01

    Novel insights are provided regarding aerobic chemolithotrophic growth of Thermocrinis ruber OC14/7/2 on the electron donors arsenite and monothioarsenate. Thermocrinis ruber is a hyperthermophilic bacterium that thrives in pH-neutral to alkaline hot springs and grows on hydrogen, elemental sulfur, and thiosulfate. Our study showed that T. ruber can also utilize arsenite as sole electron donor producing arsenate. Growth rates of 0.024 h(-1) were lower than for oxidation of thiosulfate to sulfate (μ = 0.247 h(-1)). Fast growth was observed on monothioarsenate (μ = 0.359 h(-1)), comprising different abiotic and biotic redox interactions. The initial dominant process was abiotic transformation of monothioarsenate to arsenate and elemental sulfur, followed by microbial oxidation of sulfur to sulfate. Elevated microbial activity during stationary growth of T. ruber might be explained by microbial oxidation of thiosulfate and arsenite, both also products of abiotic monothioarsenate transformation. However, the observed rapid decrease of monothioarsenate, exceeding concentrations in equilibrium with its products, also indicates direct microbial oxidation of arsenic-bond S(-II) to sulfate. Free sulfide was oxidized abiotically too fast to play a role as electron donor for T. ruber. Our present laboratory and previous field studies suggest that thioarsenates can either indirectly or directly be used by (hyper)thermophiles in arsenic-sulfidic environments. PMID:25251939

  8. Method for the growth of large low-defect single crystals

    NASA Technical Reports Server (NTRS)

    Powell, J. Anthony (Inventor); Neudeck, Philip G. (Inventor); Trunek, Andrew J. (Inventor); Spry, David J. (Inventor)

    2008-01-01

    A method and the benefits resulting from the product thereof are disclosed for the growth of large, low-defect single-crystals of tetrahedrally-bonded crystal materials. The process utilizes a uniquely designed crystal shape whereby the direction of rapid growth is parallel to a preferred crystal direction. By establishing several regions of growth, a large single crystal that is largely defect-free can be grown at high growth rates. This process is particularly suitable for producing products for wide-bandgap semiconductors, such as SiC, GaN, AlN, and diamond. Large low-defect single crystals of these semiconductors enable greatly enhanced performance and reliability for applications involving high power, high voltage, and/or high temperature operating conditions.

  9. Nitrogen effects on silicon growth, defects, and carrier lifetime

    SciTech Connect

    Ciszek, T.F.; Wang, T.H.; Burrows, R.W.

    1995-08-01

    Silicon crystal or multicrystal growth in N{sub 2} or partial-N{sub 2} atmospheres can provide mechanical strengthening, lower purge-gas costs (nitrogen from liquid sources is about a factor of 4 less expensive than argon from liquid sources), and reduce swirl-type microdefect formation in dislocation-free (DF) crystals. There is not much literature on electrical effects of N in Si, including lifetime effects. We studied the effects of Si growth in atmospheres containing N{sub 2} on minority charge carrier lifetime E using the float-zone (FZ) crystal growth method. Ingots were grown with purge gases that ranged from pure argon (99.9995%) to pure N{sub 2} (99-999%). We found that multicrystalline silicon ingot growth in a partial or total nitrogen ambient has a negligible effect on {tau}. Values of 40 {mu}s < {tau} < 100 {mu}s were typical regardless of ambient. For DF growth, the degradation of {tau} is minimal and {tau} values above 1000 {mu}s are obtained if the amount of N{sub 2} in the purge gas is below the level at which nitride compounds form in the melt and disrupt DF growth.

  10. Growth of and defect reduction in nanoscale materials

    DOEpatents

    Jensen, Kenneth J.; Mickelson, William E.; Zettl, Alex K.

    2011-01-04

    Methods by which the growth of a nanostructure may be precisely controlled by an electrical current are described here. In one embodiment, an interior nanostructure is grown to a predetermined geometry inside another nanostructure, which serves as a reaction chamber. The growth is effected by a catalytic agent loaded with feedstock for the interior nanostructure. Another embodiment allows a preexisting marginal quality nanostructure to be zone refined into a higher-quality nanostructure by driving a catalytic agent down a controlled length of the nanostructure with an electric current. In both embodiments, the speed of nanostructure formation is adjustable, and the growth may be stopped and restarted at will. The catalytic agent may be doped or undoped to produce semiconductor effects, and the bead may be removed via acid etching.

  11. Does the aerobic capacity of fish muscle change with growth rates?

    PubMed

    Pelletier, D; Guderley, H; Dutil, J D

    1993-08-01

    To ascertain whether growth rate modifies the oxidative capacity of fish white muscle, we examined the effects of individual growth rate on the activities of four mitochondrial enzymes in white muscle of the fast growing Atlantic cod,Gadus morhua. Growth rates were individually monitored in cod held at three acclimation temperatures during experiments repeated in four seasons. The size dependence of citrate synthase (CS), cytochrome C oxidase (CCO) and β-hydroxyacyl CoA dehydrogenase (HOAD) activities was established using wild cod ranging from 115 to 17,350 g. Given their negative allometry, CS and CCO activities in the experimental cod were corrected to those expected for a 1.2 kg animal. HOAD activities did not change with size. The specific activities of CCO and CS were positively correlated with growth rate. However, for both enzymes, season explained more of the variability than growth rate or temperature. Season was the only factor to significantly affect the activity of HOAD, while temperature and season interacted to determine glutamate dehydrogenase activity. CS activity was positively correlated with the initial condition of the cod, which differed among the seasons. The other enzymes did not show this relationship. The independent changes of these enzymes suggest that mitochondria undergo qualitative modifications with changes in growth rate, season and size. Although growth rate and the activities of CCO and CS are positively correlated, the activity of the mitochondrial enzymes is more affected by size, physical condition and season. PMID:24202687

  12. Defects in silicon effect on device performance and relationship to crystal growth conditions

    NASA Technical Reports Server (NTRS)

    Jastrzebski, L.

    1985-01-01

    A relationship between material defects in silicon and the performance of electronic devices will be described. A role which oxygen and carbon in silicon play during the defects generation process will be discussed. The electronic properties of silicon are a strong function of the oxygen state in the silicon. This state controls mechanical properties of silicon efficiency for internal gettering and formation of defects in the device's active area. In addition, to temperature, time, ambience, and the cooling/heating rates of high temperature treatments, the oxygen state is a function of the crystal growth process. The incorporation of carbon and oxygen into silicon crystal is controlled by geometry and rotation rates applied to crystal and crucible during crystal growths. Also, formation of nucleation centers for oxygen precipitation is influenced by the growth process, although there is still a controversy which parameters play a major role. All these factors will be reviewed with special emphasis on areas which are still ambiguous and controversial.

  13. Ability of Cecal Cultures to Inhibit Growth of Salmonella Typhimurium during Aerobic Incubation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction: Poultry can serve as reservoirs for Salmonella; however, chicks provided cultures of cecal bacteria develop resistance to colonization by Salmonella. Research has indicated that cecal bacteria metabolize organic acids to produce substances that inhibit Salmonella growth. Purpose: The...

  14. Growth and Printability of Multilayer Phase Defects on EUV MaskBlanks

    SciTech Connect

    Liang, Ted; Ultanir, Erdem; Zhnag, Guojing; Park, Seh-Jin; Anderson, Erik; Gullikson, Eric; Naulleau, Patrick; Salmassi, Farhad; Mirkarimi, Paul; Spiller, Eberhard; Baker, Sherry

    2007-06-10

    The ability to fabricate defect-free mask blanks is a well-recognized challenge in enabling extreme ultraviolet lithography (EUVL) for semiconductor manufacturing. Both the specification and reduction of defects necessitate the understanding of their printability and how they are generated and grow during Mo-Si multilayer (ML) deposition. A ML phase defect can be depicted by its topographical profile on the surface as either a bump or pit, which is then characterized by height or depth and width. The complexity of such seemingly simple phase defects lies in the many ways they can be generated and the difficulties of measuring their physical shape/size and optical effects on printability. An effective way to study phase defects is to use a programmed defect mask (PDM) as 'model' test sample where the defects are produced with controlled growth on a ML blank and accurate placement in varying proximity to absorber patterns on the mask. This paper describes our recent study of ML phase defect printability with resist data from exposures of a ML PDM on the EUV micro-exposure tool (MET, 5X reduction with 0.3NA).

  15. Macrovoid Defect Growth during Evaporative Casting of Polymeric Membranes

    NASA Technical Reports Server (NTRS)

    Greenberg, A. R.; Khare, V. P.; Zartman, J.; Krantz, W. B.; Todd, P.

    2003-01-01

    Macrovoid (MV) formation is a significant problem in evaporatively cast polymeric membranes. MVs are large, elongated or teardrop-shaped pores (10-50 micron) that can impair membrane structural integrity. Although MVs have been extensively studied, there is no general agreement on the mechanisms governing MV growth. Recently, our research group has formulated the solutocapillary convection (SC) hypothesis, which contends that MV growth involves three principal forces: a Marangoni force generated by surface tension gradients within the MV interface, a viscous drag force, and a gravitationally induced body force. Two sets of complementary experiments were conducted to test the SC hypothesis. Ground-based videomicroscopy flow-visualization (VMFV) was utilized to measure the flow velocities at the MV-casting solution interface and deep within the casting solution. The measurements were performed with casting solutions containing 10 wt% cellulose acetate (CA), 30 wt% H2O, 60 wt% acetone, and 200- ppm TiO2 particles for flow visualization, and the surface tension was controlled by surfactant addition. Qualitatively, the experiments indicated that MV growth occurs in three distinct phases: (1) a very rapid initial growth period, (2) a much slower growth phase, and (3) absorption of selected MVs into the expanding demixed region. The presence of tracer particles inside the MVs suggests the presence of a convective flow, which transfers the particles from the bulk solution to the MV interior. Although the VMFV experiments did not establish any surfactant effect on the interfacial velocities, a statistically significant effect on the MV number density was observed. In the second set of experiments, membranes were cast aboard a KC-135 aircraft under 0-g and 2-g conditions. Despite careful attention to the design and fabrication of the membrane casting apparatus (MCA), several problems were encountered, the most significant of which was the contamination of the casting

  16. Identification and Quantification of Volatile Chemical Spoilage Indexes Associated with Bacterial Growth Dynamics in Aerobically Stored Chicken.

    PubMed

    Mikš-Krajnik, Marta; Yoon, Yong-Jin; Ukuku, Dike O; Yuk, Hyun-Gyun

    2016-08-01

    Volatile organic compounds (VOCs) as chemical spoilage indexes (CSIs) of raw chicken breast stored aerobically at 4, 10, and 21 °C were identified and quantified using solid phase microextraction (SPME) combined with gas chromatography-mass spectrometry (GC-MS). The growth dynamics of total viable count (TVC), psychrotrophs, Pseudomonas spp., lactic acid bacteria (LAB), Brochothrix thermosphacta and H2 S producing bacteria were characterized based on maximum growth rates (μmax ), maximal microbial concentration (Nmax ) and at the moment of microbial shelf life (Svalues ), calculated from Gompertz-fitted growth curves. Pseudomonas spp. was predominant species, while B. thermosphacta was characterized by the highest μmax . The microbiological and sensory shelf lives were estimated based on TVC, Pseudomonas spp., and B. thermosphacta counts and sensory evaluation, respectively. Among 27 VOCs identified by GC-MS in spoiled chicken samples, ethanol (EtOH), 1-butanol-3-methyl (1But-3M), and acetic acid (C2 ) achieved the highest Pearson's correlation coefficients of 0.66, 0.61, and 0.59, respectively, with TVC, regardless of storage temperature. Partial least squares (PLS) regression revealed that the synthesis of 1But-3M and C2 was most likely induced by the metabolic activity of B. thermosphacta and LAB, while EtOH was attributed to Pseudomonas spp. The increase in concentration of selected volatile spoilage markers (EtOH, 1But-3M, and C2 ) in the headspace over spoiled chicken breast was found to be statistically significant (P < 0.05) with TVC growth. These findings highlight the possibility of analyzing the combination of 3 selected spoilage markers: EtOH, 1But-3M, and C2 as rapid evaluation for poultry quality testing using SPME-GC-MS. PMID:27332555

  17. X-ray topographic study of growth defects of trans-stilbene crystals grown from solutions

    NASA Astrophysics Data System (ADS)

    Klapper, Helmut; Zaitseva, Natalia; Carman, Leslie

    2015-11-01

    Single crystals of trans-stilbene, C14H12, with properties suitable for high-energy neutron detection were grown from solution in anisole and toluene by the temperature reduction method with growth rates up to 6 mm/day. From these crystals, slices of appropriate orientation and thickness of 2-4 mm were cut and studied by X-ray diffraction topography applying the Lang method using CuKα radiation. The topographs exhibit growth defects such as liquid inclusions, dislocations, striations, and faulty growth-sector boundaries. These defects occur in the same typical arrangements and geometries as is observed in all kinds of crystals grown on habit faces from solution. Besides growth dislocations originating from inclusions and propagating with the growth front, many plastic glide dislocations in the shape of loops or half-loops emitted from inclusions by stress relaxation are observed. The glide system underlying this plasticity is discussed.

  18. Dyskeratosis Congenita Dermal Fibroblasts are Defective in Supporting the Clonogenic Growth of Epidermal Keratinocytes

    PubMed Central

    Buckingham, Erin M.; Goldman, Frederick D.; Klingelhutz, Aloysius J.

    2012-01-01

    Telomere shortening is associated with cellular senescence and aging. Dyskeratosis congenita (DC) is a premature aging syndrome caused by mutations in genes for telomerase components or telomere proteins. DC patients have very short telomeres and exhibit aging-associated pathologies including epidermal abnormalities and bone marrow failure. Here, we show that DC skin fibroblasts are defective in their ability to support the clonogenic growth of epidermal keratinocytes. Conditioned media transfer experiments demonstrated that this defect was largely due to lack of a factor or factors secreted from the DC fibroblasts. Compared to early passage normal fibroblasts, DC fibroblasts express significantly lower transcript levels of several genes that code for secreted proteins, including Insulin-like Growth Factor 1 (IGF1) and Hepatocyte Growth Factor (HGF). Aged normal fibroblasts with short telomeres also had reduced levels of IGF1 and HGF, similar to early passage DC fibroblasts. Knockdown of IGF1 or HGF in normal fibroblasts caused a reduction in the capacity of conditioned media from these fibroblasts to support keratinocyte clonogenic growth. Surprisingly, reconstitution of telomerase in DC fibroblasts did not significantly increase transcript levels of IGF1 or HGF or substantially increase the ability of the fibroblasts to support keratinocyte growth, indicating that the gene expression defect is not readily reversible. Our results suggest that telomere shortening in dermal fibroblasts leads to reduction in expression of genes such as IGF1 and HGF and that this may cause a defect in supporting normal epidermal proliferation. PMID:23251848

  19. Improved Czochralski growth and activator efficiency of cerium doped yttrium aluminum garnet by defect engineering

    NASA Astrophysics Data System (ADS)

    Haven, Drew Thomas

    The past several decades have seen a genuine surge in development of scintillator materials for use in a multitude of applications ranging from high energy physics to medical imaging. Despite the rapid materials discovery that has been undertaken in the search for better scintillators, a host of defects still limit scintillator performance in many promising materials. Thus the key to tapping into a scintillators full potential lies in understanding and modifying their defect structure through a process known as defect engineering. One such promising visible light scintillator is cerium doped yttrium aluminum garnet (Ce:YAG). Despite characteristics that make Ce:YAG an excellent yellow phosphor that see it commonly used in fluorescent lights and while light LEDs, performance hindering defects severely limited its potential as a bulk scintillator, a critical defect being that of UV defect luminescence. By successfully building a new Czochralski (CZ) furnace, samples could be grown with careful control over growth conditions to study and reduce these defects. All samples were grown in similar conditions by the CZ method with a (111) oriented undoped YAG seed. Several original approaches were developed in this study to reduce defects or mitigate their influence. The first method of solving the problem relied on recognizing that what many in the past identified as visible scintillation light was in fact UV defect luminescence. By using multiple photodetectors it was demonstrated that when higher cerium doping levels are involved in Ce:YAG, luminescence is not decreased due to self-absorption as previously thought, but rather UV defect emission is quenched in favor of visible emission. Once established, new avenues of research became available. Another study demonstrates Ce:YAG grown by the Czochralski method in alumina rich conditions is an effective method for reducing the number of UV producing yttrium antisite defects. This culminated in record energy resolution of

  20. Amorphous carbon film growth on Si: Correlation between stress and generation of defects into the substrate

    SciTech Connect

    Brusa, R.S.; Macchi, C.; Mariazzi, S.; Karwasz, G.P.; Laidani, N.; Bartali, R.; Anderle, M.

    2005-05-30

    Amorphous carbon films of several thicknesses were prepared by graphite sputtering on crystalline silicon substrate. The samples were depth profiled with positron annihilation spectroscopy for open-volume measurements and characterized for their residual internal stress. It was found that after film growth the substrate presents vacancy-like defects decorated by oxygen in a layer extending in the substrate by several tens of nanometers beyond the film/Si interface. The width of the defected layer and the decoration of vacancy-like defects are directly and inversely proportional to the measured intensity of the residual stress, respectively. These findings indicate the existence of a relaxation mechanism of the stress in the films that involves deeply the substrate. The decorated vacancy-like defects are suggested to be bounded to dislocations induced in the substrate by the stress relaxation.

  1. Irradiation-induced grain growth and defect evolution in nanocrystalline zirconia with doped grain boundaries.

    PubMed

    Dey, Sanchita; Mardinly, John; Wang, Yongqiang; Valdez, James A; Holesinger, Terry G; Uberuaga, Blas P; Ditto, Jeff J; Drazin, John W; Castro, Ricardo H R

    2016-06-22

    Grain boundaries are effective sinks for radiation-induced defects, ultimately impacting the radiation tolerance of nanocrystalline materials (dense materials with nanosized grains) against net defect accumulation. However, irradiation-induced grain growth leads to grain boundary area decrease, shortening potential benefits of nanostructures. A possible approach to mitigate this is the introduction of dopants to target a decrease in grain boundary mobility or a reduction in grain boundary energy to eliminate driving forces for grain growth (using similar strategies as to control thermal growth). Here we tested this concept in nanocrystalline zirconia doped with lanthanum. Although the dopant is observed to segregate to the grain boundaries, causing grain boundary energy decrease and promoting dragging forces for thermally activated boundary movement, irradiation induced grain growth could not be avoided under heavy ion irradiation, suggesting a different growth mechanism as compared to thermal growth. Furthermore, it is apparent that reducing the grain boundary energy reduced the effectiveness of the grain boundary as sinks, and the number of defects in the doped material is higher than in undoped (La-free) YSZ. PMID:27282392

  2. Spontaneous, Defect-Free Kinking via Capillary Instability during Vapor-Liquid-Solid Nanowire Growth.

    PubMed

    Li, Yanying; Wang, Yanming; Ryu, Seunghwa; Marshall, Ann F; Cai, Wei; McIntyre, Paul C

    2016-03-01

    Kinking, a common anomaly in nanowire (NW) vapor-liquid-solid (VLS) growth, represents a sudden change of the wire's axial growth orientation. This study focuses on defect-free kinking during germanium NW VLS growth, after nucleation on a Ge (111) single crystal substrate, using Au-Ge catalyst liquid droplets of defined size. Statistical analysis of the fraction of kinked NWs reveals the dependence of kinking probability on the wire diameter and the growth temperature. The morphologies of kinked Ge NWs studied by electron microscopy show two distinct, defect-free, kinking modes, whose underlying mechanisms are explained with the help of 3D multiphase field simulations. Type I kinking, in which the growth axis changes from vertical [111] to ⟨110⟩, was observed in Ge NWs with a nominal diameter of ∼20 nm. This size coincides with a critical diameter at which a spontaneous transition from ⟨111⟩ to ⟨110⟩ growth occurs in the phase field simulations. Larger diameter NWs only exhibit Type II kinking, in which the growth axis changes from vertical [111] directly to an inclined ⟨111⟩ axis during the initial stages of wire growth. This is caused by an error in sidewall facet development, which produces a shrinkage in the area of the (111) growth facet with increasing NW length, causing an instability of the Au-Ge liquid droplet at the tip of the NW. PMID:26837774

  3. Chitosan conduits combined with nerve growth factor microspheres repair facial nerve defects

    PubMed Central

    Liu, Huawei; Wen, Weisheng; Hu, Min; Bi, Wenting; Chen, Lijie; Liu, Sanxia; Chen, Peng; Tan, Xinying

    2013-01-01

    Microspheres containing nerve growth factor for sustained release were prepared by a compound method, and implanted into chitosan conduits to repair 10-mm defects on the right buccal branches of the facial nerve in rabbits. In addition, chitosan conduits combined with nerve growth factor or normal saline, as well as autologous nerve, were used as controls. At 90 days post-surgery, the muscular atrophy on the right upper lip was more evident in the nerve growth factor and normal sa-line groups than in the nerve growth factor-microspheres and autologous nerve groups. physiological analysis revealed that the nerve conduction velocity and amplitude were significantly higher in the nerve growth factor-microspheres and autologous nerve groups than in the nerve growth factor and normal saline groups. Moreover, histological observation illustrated that the di-ameter, number, alignment and myelin sheath thickness of myelinated nerves derived from rabbits were higher in the nerve growth factor-microspheres and autologous nerve groups than in the nerve growth factor and normal saline groups. These findings indicate that chitosan nerve conduits bined with microspheres for sustained release of nerve growth factor can significantly improve facial nerve defect repair in rabbits. PMID:25206635

  4. Chitosan conduits combined with nerve growth factor microspheres repair facial nerve defects.

    PubMed

    Liu, Huawei; Wen, Weisheng; Hu, Min; Bi, Wenting; Chen, Lijie; Liu, Sanxia; Chen, Peng; Tan, Xinying

    2013-11-25

    Microspheres containing nerve growth factor for sustained release were prepared by a compound method, and implanted into chitosan conduits to repair 10-mm defects on the right buccal branches of the facial nerve in rabbits. In addition, chitosan conduits combined with nerve growth factor or normal saline, as well as autologous nerve, were used as controls. At 90 days post-surgery, the muscular atrophy on the right upper lip was more evident in the nerve growth factor and normal sa-line groups than in the nerve growth factor-microspheres and autologous nerve groups. physiological analysis revealed that the nerve conduction velocity and amplitude were significantly higher in the nerve growth factor-microspheres and autologous nerve groups than in the nerve growth factor and normal saline groups. Moreover, histological observation illustrated that the di-ameter, number, alignment and myelin sheath thickness of myelinated nerves derived from rabbits were higher in the nerve growth factor-microspheres and autologous nerve groups than in the nerve growth factor and normal saline groups. These findings indicate that chitosan nerve conduits bined with microspheres for sustained release of nerve growth factor can significantly improve facial nerve defect repair in rabbits. PMID:25206635

  5. Proline biosynthesis augments tumor cell growth and aerobic glycolysis: involvement of pyridine nucleotides

    PubMed Central

    Liu, Wei; Hancock, Chad N.; Fischer, Joseph W.; Harman, Meredith; Phang, James M.

    2015-01-01

    The metabolism of the nonessential amino acid proline contributes to tumor metabolic reprogramming. Previously we showed that MYC increases proline biosynthesis (PB) from glutamine. Here we show MYC increases the expression of the enzymes in PB at both protein and mRNA levels. Blockade of PB decreases tumor cell growth and energy production. Addition of Δ1-pyrroline-5-carboxylate (P5C) or proline reverses the effects of P5C synthase knockdown but not P5C reductases knockdown. Importantly, the reversal effect of proline was blocked by concomitant proline dehydrogenase/oxidase (PRODH/POX) knockdown. These findings suggest that the important regulatory contribution of PB to tumor growth derives from metabolic cycling between proline and P5C rather than product proline or intermediate P5C. We further document the critical role of PB in maintaining pyridine nucleotide levels by connecting the proline cycle to glycolysis and to the oxidative arm of the pentose phosphate pathway. These findings establish a novel function of PB in tumorigenesis, linking the reprogramming of glucose, glutamine and pyridine nucleotides, and may provide a novel target for antitumor therapy. PMID:26598224

  6. Beta-nerve growth factor promotes neurogenesis and angiogenesis during the repair of bone defects

    PubMed Central

    Chen, Wei-hui; Mao, Chuan-qing; Zhuo, Li-li; Ong, Joo L.

    2015-01-01

    We previously showed that the repair of bone defects is regulated by neural and vascular signals. In the present study, we examined the effect of topically applied β-nerve growth factor (β-NGF) on neurogenesis and angiogenesis in critical-sized bone defects filled with collagen bone substitute. We created two symmetrical defects, 2.5 mm in diameter, on either side of the parietal bone of the skull, and filled them with bone substitute. Subcutaneously implanted osmotic pumps were used to infuse 10 μg β-NGF in PBS (β-NGF + PBS) into the right-hand side defect, and PBS into the left (control) defect, over the 7 days following surgery. Immunohistochemical staining and hematoxylin-eosin staining were carried out at 3, 7, 14, 21 and 28 days postoperatively. On day 7, expression of β III-tubulin was lower on the β-NGF + PBS side than on the control side, and that of neurofilament 160 was greater. On day 14, β III-tubulin and protein gene product 9.5 were greater on the β-NGF + PBS side than on the control side. Vascular endothelial growth factor expression was greater on the experimental side than the control side at 7 days, and vascular endothelial growth factor receptor 2 expression was elevated on days 14 and 21, but lower than control levels on day 28. However, no difference in the number of blood vessels was observed between sides. Our results indicate that topical application of β-NGF promoted neurogenesis, and may modulate angiogenesis by promoting nerve regeneration in collagen bone substitute-filled defects. PMID:26330843

  7. Defective minor spliceosome mRNA processing results in isolated familial growth hormone deficiency

    PubMed Central

    Argente, Jesús; Flores, Raquel; Gutiérrez-Arumí, Armand; Verma, Bhupendra; Martos-Moreno, Gabriel Á; Cuscó, Ivon; Oghabian, Ali; Chowen, Julie A; Frilander, Mikko J; Pérez-Jurado, Luis A

    2014-01-01

    The molecular basis of a significant number of cases of isolated growth hormone deficiency remains unknown. We describe three sisters affected with severe isolated growth hormone deficiency and pituitary hypoplasia caused by biallelic mutations in the RNPC3 gene, which codes for a minor spliceosome protein required for U11/U12 small nuclear ribonucleoprotein (snRNP) formation and splicing of U12-type introns. We found anomalies in U11/U12 di-snRNP formation and in splicing of multiple U12-type introns in patient cells. Defective transcripts include preprohormone convertases SPCS2 and SPCS3 and actin-related ARPC5L genes, which are candidates for the somatotroph-restricted dysfunction. The reported novel mechanism for familial growth hormone deficiency demonstrates that general mRNA processing defects of the minor spliceosome can lead to very narrow tissue-specific consequences. Subject Categories Genetics, Gene Therapy ' Genetic Disease; Metabolism PMID:24480542

  8. Defect-phase-dynamics approach to statistical domain-growth problem of clock models

    NASA Technical Reports Server (NTRS)

    Kawasaki, K.

    1985-01-01

    The growth of statistical domains in quenched Ising-like p-state clock models with p = 3 or more is investigated theoretically, reformulating the analysis of Ohta et al. (1982) in terms of a phase variable and studying the dynamics of defects introduced into the phase field when the phase variable becomes multivalued. The resulting defect/phase domain-growth equation is applied to the interpretation of Monte Carlo simulations in two dimensions (Kaski and Gunton, 1983; Grest and Srolovitz, 1984), and problems encountered in the analysis of related Potts models are discussed. In the two-dimensional case, the problem is essentially that of a purely dissipative Coulomb gas, with a sq rt t growth law complicated by vertex-pinning effects at small t.

  9. Reconstructing jaw defects with MSCs and PLGA-encapsulated growth factors.

    PubMed

    Tee, Boon Ching; Desai, Kashappa Goud H; Kennedy, Kelly S; Sonnichsen, Brittany; Kim, Do-Gyoon; Fields, Henry W; Mallery, Susan R; Schwendeman, Steven P; Sun, Zongyang

    2016-01-01

    Cell and growth factor-based tissue engineering has shown great potentials for skeletal regeneration. This study tested its feasibility in reconstructing large mandibular defects and compared the efficacy of varied construction materials and sealing methods. Bilateral mandibular critical-size (5-cm(3)) defects were created on six 4-month-old domestic pigs, and grafted with β-tricalcium phosphate (βTCP) only (Group-A), βTCP with autologous bone marrow-derived mesenchymal stem cells (BM-MSCs) (Group-B), and βTCP with BM-MSCs and biodegradable poly(lactic-co-glycolic acid) (PLGA) microspheres containing bone morphogenetic protein-2 (BMP-2) and vascular endothelial growth factor (VEGF) (Group-C). The buccal sides of Groups-B/-C were either sealed by fibrin sealant or by a biodegradable PLGA barrier membrane before soft-tissue closure. Computed tomography (CT), microCT and histology analyses were performed 12 weeks postoperatively. In vitro data demonstrated that BM-MSCs, with MSC properties confirmed, remained vital after integration with βTCP; and PLGA microspheres exhibited an initial burst followed by slow and continuous release of growth factors over a period of 28 days. In vivo data demonstrated that Group-B/-C sites had significantly greater gap obliteration, higher tissue mineral densities and more residual βTCP granules (p<0.05, Kruskal-Wallis tests). Qualitatively, Group-B/-C defect sites had started remodeling while Group-A sites were mainly forming new bone to bridge the gaps. Furthermore, βTCP degradation was not mediated by macrophages or osteoclasts, and was significantly slowed down by sealing the defects with barrier membrane. Combined, these data present a promising formulation composed of βTCP granules, autologous MSCs, controlled-release growth factors and biodegradable PLGA barrier membrane for the reconstruction of critical-size mandibular defects. PMID:27398152

  10. Reconstructing jaw defects with MSCs and PLGA-encapsulated growth factors

    PubMed Central

    Tee, Boon Ching; Desai, Kashappa Goud H; Kennedy, Kelly S; Sonnichsen, Brittany; Kim, Do-Gyoon; Fields, Henry W; Mallery, Susan R; Schwendeman, Steven P; Sun, Zongyang

    2016-01-01

    Cell and growth factor-based tissue engineering has shown great potentials for skeletal regeneration. This study tested its feasibility in reconstructing large mandibular defects and compared the efficacy of varied construction materials and sealing methods. Bilateral mandibular critical-size (5-cm3) defects were created on six 4-month-old domestic pigs, and grafted with β-tricalcium phosphate (βTCP) only (Group-A), βTCP with autologous bone marrow-derived mesenchymal stem cells (BM-MSCs) (Group-B), and βTCP with BM-MSCs and biodegradable poly(lactic-co-glycolic acid) (PLGA) microspheres containing bone morphogenetic protein-2 (BMP-2) and vascular endothelial growth factor (VEGF) (Group-C). The buccal sides of Groups-B/-C were either sealed by fibrin sealant or by a biodegradable PLGA barrier membrane before soft-tissue closure. Computed tomography (CT), microCT and histology analyses were performed 12 weeks postoperatively. In vitro data demonstrated that BM-MSCs, with MSC properties confirmed, remained vital after integration with βTCP; and PLGA microspheres exhibited an initial burst followed by slow and continuous release of growth factors over a period of 28 days. In vivo data demonstrated that Group-B/-C sites had significantly greater gap obliteration, higher tissue mineral densities and more residual βTCP granules (p<0.05, Kruskal-Wallis tests). Qualitatively, Group-B/-C defect sites had started remodeling while Group-A sites were mainly forming new bone to bridge the gaps. Furthermore, βTCP degradation was not mediated by macrophages or osteoclasts, and was significantly slowed down by sealing the defects with barrier membrane. Combined, these data present a promising formulation composed of βTCP granules, autologous MSCs, controlled-release growth factors and biodegradable PLGA barrier membrane for the reconstruction of critical-size mandibular defects. PMID:27398152

  11. Making consistent contacts to graphene: effect of architecture and growth induced defects.

    PubMed

    Krishna Bharadwaj, B; Nath, Digbijoy; Pratap, Rudra; Raghavan, Srinivasan

    2016-05-20

    The effects of contact architecture, graphene defect density and metal-semiconductor work function difference on the resistivity of metal-graphene contacts have been investigated. An architecture with metal on the bottom of graphene is found to yield resistivities that are lower, by a factor of four, and most consistent as compared to metal on top of graphene. Growth defects in graphene film were found to further reduce resistivity by a factor of two. Using a combination of method and metal used, the contact resistivity of graphene has been decreased by a factor of 10 to 1200 ± 250 [Formula: see text] using palladium as the contact metal. While the improved consistency is due to the metal being able to contact uncontaminated graphene in the metal on the bottom architecture, lower contact resistivities observed on defective graphene with the same metal are attributed to the increased number of modes of quantum transport in the channel. PMID:27070858

  12. Making consistent contacts to graphene: effect of architecture and growth induced defects

    NASA Astrophysics Data System (ADS)

    Krishna Bharadwaj, B.; Nath, Digbijoy; Pratap, Rudra; Raghavan, Srinivasan

    2016-05-01

    The effects of contact architecture, graphene defect density and metal–semiconductor work function difference on the resistivity of metal–graphene contacts have been investigated. An architecture with metal on the bottom of graphene is found to yield resistivities that are lower, by a factor of four, and most consistent as compared to metal on top of graphene. Growth defects in graphene film were found to further reduce resistivity by a factor of two. Using a combination of method and metal used, the contact resistivity of graphene has been decreased by a factor of 10 to 1200 ± 250 {{Ω }}μ {{m}} using palladium as the contact metal. While the improved consistency is due to the metal being able to contact uncontaminated graphene in the metal on the bottom architecture, lower contact resistivities observed on defective graphene with the same metal are attributed to the increased number of modes of quantum transport in the channel.

  13. In-growth of an electrically active defect in high-purity silicon after proton irradiation

    SciTech Connect

    Nylandsted Larsen, A.; Juul Pedersen, H.; Christian Petersen, M.; Privitera, V.; Gurimskaya, Y.; Mesli, A.

    2013-12-14

    Defect-related energy levels in the lower half of the band gap of silicon have been studied with transient-capacitance techniques in high-purity, carbon and oxygen lean, plasma-enhanced chemical-vapor deposition grown, n-and p-type silicon layers after 2-MeV proton irradiations at temperatures at or just below room temperature. The in-growth of a distinct line in deep-level transient spectroscopy spectra, corresponding to a level in the band gap at E{sub V} + 0.357 eV where E{sub V} is the energy of the valence band edge, takes place for anneal temperatures at around room temperature with an activation energy of 0.95 ± 0.08 eV. The line disappears at an anneal temperature of around 450 K. The corresponding defect is demonstrated not to contain boron, carbon, oxygen, or phosphorus. Possible defect candidates are discussed.

  14. Controlled growth of a line defect in graphene and implications for gate-tunable valley filtering

    NASA Astrophysics Data System (ADS)

    Chen, J.-H.; Autès, G.; Alem, N.; Gargiulo, F.; Gautam, A.; Linck, M.; Kisielowski, C.; Yazyev, O. V.; Louie, S. G.; Zettl, A.

    2014-03-01

    Atomically precise tailoring of graphene can enable unusual transport pathways and new nanometer-scale functional devices. Here we describe a recipe for the controlled production of highly regular "5-5-8" line defects in graphene by means of simultaneous electron irradiation and Joule heating by applied electric current. High-resolution transmission electron microscopy reveals individual steps of the growth process. Extending earlier theoretical work suggesting valley-discriminating capabilities of a graphene 5-5-8 line defect, we perform first-principles calculations of transport and find a strong energy dependence of valley polarization of the charge carriers across the defect. These findings inspire us to propose a compact electrostatically gated "valley valve" device, a critical component for valleytronics.

  15. Numerical simulation of point defect transport in floating-zone silicon single crystal growth

    NASA Astrophysics Data System (ADS)

    Larsen, T. L.; Jensen, L.; Lüdge, A.; Riemann, H.; Lemke, H.

    2001-08-01

    This work compares simulations of intrinsic point defect transport for a 0.8″ crystal for two different values of the point defect recombination factor, thereafter utilizing the model for two more commercially relevant 4″ crystals, grown with the needle-eye technique. Using this approach to study defect transport in floating-zone configurations is the novelty of this work. The simulation of the thin 0.8″ crystal is compared to the qualitative Voronkov model and DLTS experiments, to give some insights on the applied recombination factors. The work concludes that for large crystals, grown in the vacancy region, the influence of an uncertain recombination factor is not as significant as for smaller crystals grown with a near critical growth parameter.

  16. A Comparison Study of Creep-Fatigue Defect Growth Evaluations for a SFR IHTS Piping

    NASA Astrophysics Data System (ADS)

    Park, Chang-Gyu; Kim, Jong-Bum; Lee, Jae-Han

    A defect behavior is one of the principal concerns to be dealt with for a structural integrity since defects may lead to the failure of a SFR(Sodium-cooled Fast Reactor) structure under high temperature loading conditions. A thin-walled and large diametric piping is adopted for the IHTS (Intermediate Heat Transport System) piping system of a SFR to enhance the system's economy and to reduce the thermal stress level. The structural material for the piping is Type 316 austenitic stainless steel. In this study, a defect growth evaluation of IHTS piping was performed for a semi-elliptical surface defect subjected to a combined mechanical loading and thermal loading of a high temperature above 500°C including a cyclic loading condition corresponding to a reactor refueling cycle. The creep-fatigue defect behavior evaluations were carried out by following the French Assessment Procedure A16, the UK Assessment Procedure R5 and the JNC procedure. The results were compared with each other and their strong and weak points were discussed. Also the degree of conservatism of each procedure was reviewed.

  17. Stochastic growth dynamics and composite defects in quenched immiscible binary condensates

    NASA Astrophysics Data System (ADS)

    Liu, I.-K.; Pattinson, R. W.; Billam, T. P.; Gardiner, S. A.; Cornish, S. L.; Huang, T.-M.; Lin, W.-W.; Gou, S.-C.; Parker, N. G.; Proukakis, N. P.

    2016-02-01

    We study the sensitivity of coupled condensate formation dynamics on the history of initial stochastic domain formation in the context of instantaneously quenched elongated harmonically trapped immiscible two-component atomic Bose gases. The spontaneous generation of defects in the fastest condensing component, and subsequent coarse-graining dynamics, can lead to a deep oscillating microtrap into which the other component condenses, thereby establishing a long-lived composite defect in the form of a dark-bright solitary wave. We numerically map out diverse key aspects of these competing growth dynamics, focusing on the role of shot-to-shot fluctuations and global parameter changes (initial state choices, quench parameters, and condensate growth rates), with our findings also qualitatively confirmed by realistic finite-duration quenches. We conclude that phase-separated structures observable on experimental time scales are likely to be metastable states whose form is influenced by the stability and dynamics of the spontaneously emerging dark-bright solitary wave.

  18. Theory of inception mechanism and growth of defect-induced damage in polyethylene cable insulation

    NASA Astrophysics Data System (ADS)

    Serra, S.; Montanari, G. C.; Mazzanti, G.

    2005-08-01

    We have investigated theoretically the inception mechanism and growth of the damage inside the insulation system of a polymeric cable under working conditions. We focused, in particular, our attention on damage originating from microscopic defects such as voids. In order to clarify the implications of these defects for cable failure, we have developed a theoretical model based on the theory of electrical avalanche solving numerically its basic equations. Calculations of the ionization rates of atmospheric gas filling the voids are done as a function of the applied electric stress and void dimensions. Estimates of the energy release and local damage in polyethylene produced by the resulting hot-electron discharge are given. The developed physical model of damage growth compares reasonably well with known experimental data.

  19. The TIP GROWTH DEFECTIVE1 S-Acyl Transferase Regulates Plant Cell Growth in ArabidopsisW⃞

    PubMed Central

    Hemsley, Piers A.; Kemp, Alison C.; Grierson, Claire S.

    2005-01-01

    TIP GROWTH DEFECTIVE1 (TIP1) of Arabidopsis thaliana affects cell growth throughout the plant and has a particularly strong effect on root hair growth. We have identified TIP1 by map-based cloning and complementation of the mutant phenotype. TIP1 encodes an ankyrin repeat protein with a DHHC Cys-rich domain that is expressed in roots, leaves, inflorescence stems, and floral tissue. Two homologues of TIP1 in yeast (Saccharomyces cerevisiae) and human (Homo sapiens) have been shown to have S-acyl transferase (also known as palmitoyl transferase) activity. S-acylation is a reversible hydrophobic protein modification that offers swift, flexible control of protein hydrophobicity and affects protein association with membranes, signal transduction, and vesicle trafficking within cells. We show that TIP1 binds the acyl group palmitate, that it can rescue the morphological, temperature sensitivity, and yeast casein kinase2 localization defects of the yeast S-acyl transferase mutant akr1Δ, and that inhibition of acylation in wild-type Arabidopsis roots reproduces the Tip1− mutant phenotype. Our results demonstrate that S-acylation is essential for normal plant cell growth and identify a plant S-acyl transferase, an essential research tool if we are to understand how this important, reversible lipid modification operates in plant cells. PMID:16100337

  20. Transforming Growth Factor Beta 1 Augments Calvarial Defect Healing and Promotes Suture Regeneration

    PubMed Central

    Shakir, Sameer; MacIsaac, Zoe M.; Naran, Sanjay; Smith, Darren M.; Bykowski, Michael R.; Cray, James J.; Craft, Timothy K.; Wang, Dan; Weiss, Lee; Campbell, Phil G.; Mooney, Mark P.; Losee, Joseph E.

    2015-01-01

    Background: Repair of complex cranial defects is hindered by a paucity of appropriate donor tissue. Bone morphogenetic protein 2 (BMP2) and transforming growth factor beta 1 (TGFβ1) have been shown separately to induce bone formation through physiologically distinct mechanisms and potentially improve surgical outcome for cranial defect repair by obviating the need for donor tissue. We hypothesize that a combination of BMP2 and TGFβ1 would improve calvarial defect healing by augmenting physiologic osteogenic mechanisms. Methods/Results: Coronal suturectomies (3×15 mm) were performed in 10-day-old New Zealand White rabbits. DermaMatrix™ (3×15mm) patterned with four treatments (vehicle, 350 ng BMP2, 200 ng TGFβ1, or 350 ng BMP2+200 ng TGFβ1) was placed in suturectomy sites and rabbits were euthanized at 6 weeks of age. Two-dimensional (2D) defect healing, bone volume, and bone density were quantified by computed tomography. Regenerated bone was qualitatively assessed histologically. One-way analysis of variance revealed significant group main effects for all bone quantity measures. Analysis revealed significant differences in 2D defect healing, bone volume, and bone density between the control group and all treatment groups, but no significant differences were detected among the three growth factor treatment groups. Qualitatively, TGFβ1 treatment produced bone with morphology most similar to native bone. TGFβ1-regenerated bone contained a suture-like tissue, growing from the lateral edge of the defect margin toward the midline. Unique to the BMP2 treatment group, regenerated bone contained lacunae with chondrocytes, demonstrating the presence of endochondral ossification. Conclusions/Significance: Total healing in BMP2 and TGFβ1 treatment groups is not significantly different. The combination of BMP2+TGFβ1 did not significantly increase bone healing compared with treatment with BMP2 or TGFβ1 alone postoperatively at 4 weeks. We highlight the

  1. Revealing growth defects in non-linear borate single crystals by chemical etching

    NASA Astrophysics Data System (ADS)

    Péter, Á.; Polgár, K.; Beregi, E.

    2000-01-01

    Inorganic cyclic borates such as β-BaB 2O 4 (BBO), LiB 3O 5 (LBO), CsLiB 6O 10 (CLBO) and Li 2B 4O 7 (LTB) are excellent non-linear optical (NLO) materials, particularly in the ultraviolet region. Another type of borate is YAl 3(BO 3) 4 (YAB) which is utilized as a laser host and for self-frequency doubling. Growth imperfections causing scattering and absorption of laser beams affect the performance and the use of borate single crystals. Defects, like inclusions, twins, grain boundaries and dislocations form readily in crystals grown by both the high temperature top-seeded solution growth (HTTSSG) method (BBO, LBO, YAB) and the Czochralski technique (CLBO, LTB). Chemical etching methods have been developed on various planes of the different borate crystals, in order to reveal the nature and the distribution of these defects. These methods have successfully been used to characterize NLO borate crystals. The origins of lattice defect formation are discussed in terms of the growth parameters.

  2. Growth and energy metabolism in aerobic fed-batch cultures of Saccharomyces cerevisiae: Simulation and model verification

    SciTech Connect

    Pham, H.T.B.; Larsson, G.; Enfors, S.O.

    1998-11-20

    Some yeast species are classified as being glucose sensitive, which means that they may produce ethanol also under aerobic conditions when the sugar concentration is high. A kinetic model of overflow metabolism in Saccharomyces cerevisiae was used for simulation of aerobic fed-batch cultivations. An inhibitory effect of ethanol on the maximum respiration of the yeast was observed in the experiments and included in the model. The model predicts respiration, biomass, and ethanol formation and the subsequent ethanol consumption, and was experimentally validated in fed-batch cultivations. Oscillating sugar feed with resulting oscillating carbon dioxide production did not influence the maximum respiration rate, which indicates that the pyruvate dehydrogenase complex is not involved as a bottleneck causing aerobic ethanol formation.

  3. The Role of Structural Defects and Interfacial Instabilities in the Growth Behaviour of Paracetamol

    NASA Astrophysics Data System (ADS)

    Ristic, R. I.

    The role of structural defects and interfacial instabilities in the growth behaviour of small paracetamol crystals grown from pure aqueous solution and in the presence of p-acetoxy acetanalide (PAA) were investigated. The average growth rates obtained from growth rate distributions were used to predict morphological behaviour of an assembly of small crystals versus supersaturation. It was shown that columnar shape was formed in regions of low supersaturation while a plate like form prevailed at high supersaturations. An addition of PAA led to the development of columnar crystals with an aspect ratio which varied with impurity level. Using modern optical microscopy and X-ray topography it was shown that phenomena such as interfacial instabilities accompanied by formation of inclusions and dislocations in the {110} growth sectors are the key issues for defining particle morphology, size distribution and crystal purity.

  4. Influence of mechanical disintegration on the microbial growth of aerobic sludge biomass: A comparative study of ultrasonic and shear gap homogenizers by oxygen uptake measurements.

    PubMed

    Divyalakshmi, P; Murugan, D; Sivarajan, M; Saravanan, P; Lajapathi Rai, C

    2015-11-01

    Wastewater treatment plant incorporates physical, chemical and biological processes to treat and remove the contaminants. The main drawback of conventional activated sludge process is the huge production of excess sludge, which is an unavoidable byproduct. The treatment and disposal of excess sludge costs about 60% of the total operating cost. The ideal way to reduce excess sludge production during wastewater treatment is by preventing biomass formation within the aerobic treatment train rather than post treatment of the generated sludge. In the present investigation two different mechanical devices namely, Ultrasonic and Shear Gap homogenizers have been employed to disintegrate the aerobic biomass. This study is intended to restrict the multiplication of microbial biomass and at the same time degrade the organics present in wastewater by increasing the oxidative capacity of microorganisms. The disintegrability on biomass was determined by biochemical methods. Degree of inactivation provides the information on inability of microorganisms to consume oxygen upon disruption. The soluble COD quantifies the extent of release of intra cellular compounds. The participation of disintegrated microorganism in wastewater treatment process was carried out in two identical respirometeric reactors. The results show that Ultrasonic homogenizer is very effective in the disruption of microorganisms leading to a maximum microbial growth reduction of 27%. On the other hand, Shear gap homogenizer does not favor the sludge growth reduction rather it facilitates the growth. This study also shows that for better microbial growth reduction, floc size reduction alone is not sufficient but also microbial disruption is essential. PMID:25866205

  5. Diffusion model of the formation of growth microdefects: A new approach to defect formation in crystals (Review)

    NASA Astrophysics Data System (ADS)

    Talanin, V. I.; Talanin, I. E.

    2016-03-01

    Theoretical studies of defect formation in semiconductor silicon play an important role in the creation of breakthrough ideas for next-generation technologies. A brief comparative analysis of modern theoretical approaches to the description of interaction of point defects and formation of the initial defect structure of dislocation-free silicon single crystals has been carried out. Foundations of the diffusion model of the formation of structural imperfections during the silicon growth have been presented. It has been shown that the diffusion model is based on high-temperature precipitation of impurities. The model of high-temperature precipitation of impurities describes processes of nucleation, growth, and coalescence of impurities during cooling of a crystal from 1683 to 300 K. It has been demonstrated that the diffusion model of defect formation provides a unified approach to the formation of a defect structure beginning with the crystal growth to the production of devices. The possibilities of using the diffusion model of defect formation for other semiconductor crystals and metals have been discussed. It has been shown that the diffusion model of defect formation is a platform for multifunctional solution of many key problems in modern solid state physics. Fundamentals of practical application of the diffusion model for engineering of defects in crystals with modern information technologies have been considered. An algorithm has been proposed for the calculation and analysis of a defect structure of crystals.

  6. Aerobic growth of campylobacter in media supplemented with a-ketoglutaric, lactic, and/or fumaric acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A study was conducted to examine the ability of Campylobacter spp. to grow aerobically in media supplemented with selected organic acids. Basal broth media composed of tryptose, yeast extract, and a mineral-vitamin solution was supplemented with a-ketoglutaric, lactic, and/or fumaric acids. The fina...

  7. A study of void size growth in nonequilibrium stochastic systems of point defects

    NASA Astrophysics Data System (ADS)

    Kharchenko, Dmitrii O.; Kharchenko, Vasyl O.; Bashtova, Anna I.

    2016-05-01

    We study properties of voids growth dynamics in a stochastic system of point defects in solids under nonequilibrium conditions (sustained irradiation). It is shown that fluctuations of defect production rate (external noise) increase the critical void radius comparing to a deterministic system. An automodel regime of void size growth in a stochastic system is studied in detail. Considering a homogeneous system, it is found that external noise does not change the universality of the void size distribution function; the mean void size evolves according to classical nucleation theory. The noise increases the mean void size and spreads the void size distribution. Studying dynamics of spatially extended systems it was shown that vacancies remaining in a matrix phase are able to organize into vacancy enriched domains due to an instability caused by an elastic lattice deformation. It is shown that dynamics of voids growth is defined by void sinks strength with void size growth exponent varying from 1/3 up to 1/2.

  8. A biomimetic growth factor delivery strategy for enhanced regeneration of iliac crest defects.

    PubMed

    Huri, Pinar Yilgor; Huri, Gazi; Yasar, Umit; Ucar, Yurdanur; Dikmen, Nurten; Hasirci, Nesrin; Hasirci, Vasif

    2013-08-01

    The importance of provision of growth factors in the engineering of tissues has long been shown to control the behavior of the cells within the construct and several approaches were applied toward this end. In nature, more than one type of growth factor is known to be effective during the healing of tissue defects and their peak concentrations are not always simultaneous. One of the most recent strategies includes the delivery of a combination of growth factors with the dose and timing to mimic the natural regeneration cascade. The sequential delivery of bone morphogenetic proteins BMP-2 and BMP-7 which are early and late appearing factors during bone regeneration, respectively, was shown in vitro to enhance osteoblastic differentiation of bone marrow derived mesenchymal stem cells. In the present study, the aim was to study the effectiveness of this delivery strategy in a rabbit iliac crest model. 3D plotted poly(ε-caprolactone) scaffolds were loaded with BMP carrying nanoparticles to achieve: (a) single BMP-2 or BMP-7 delivery, and (b) their combined delivery in a simultaneous or (c) sequential (biomimetic) fashion. After eight weeks of implantation, computed tomography and biomechanical tests showed better mineralized matrix formation and bone-implant union strength at the defect site in the case of sequential delivery compared to single or simultaneous delivery modes. Bone mineral density (BMD) and push-out stress were: 33.65±2.25 g cm(-3) and 14.5±2.28 MPa, respectively, and almost 2.5 fold higher in comparison to those without growth factors (BMD: 14.14±1.21 g cm(-3); PS: 6.59±0.65 MPa). This study, therefore, supports those obtained in vitro and emphasizes the importance of mimicking the natural timing of bioavailability of osteogenic factors in improving the regeneration of critical-sized bone defects. PMID:23782488

  9. Radiative defects in GaN nanocolumns: Correlation with growth conditions and sample morphology

    SciTech Connect

    Lefebvre, P.; Fernandez-Garrido, S.; Grandal, J.; Ristic, J.; Sanchez-Garcia, M.-A.; Calleja, E.

    2011-02-21

    Low-temperature photoluminescence is studied in detail in GaN nanocolumns (NCs) grown by plasma-assisted molecular beam epitaxy under various conditions (substrate temperature and impinging Ga/N flux ratio). The relative intensities of the different emission lines, in particular those related to structural defects, appear to be correlated with the growth conditions, and clearly linked to the NC sample morphology. We demonstrate, in particular, that all lines comprised between 3.10 and 3.42 eV rapidly lose intensity when the growth conditions are such that the NC coalescence is reduced. The well-known line around 3.45 eV, characteristic of GaN NC samples, shows, however, a behavior that is exactly the opposite of the other lines, namely, for growth conditions leading to reduced NC coalescence, this line tends to become more prominent, thus proving to be intrinsic to individual GaN NCs.

  10. Defect initiation/growth and energy dissipation induced by deformation and fracture

    NASA Astrophysics Data System (ADS)

    Dickinson, J. T.

    1993-01-01

    Based on our capabilities to (1) detect and characterize particle release from surfaces on fast time scales, (2) to measure rapid electrical transients, and (3) to obtain high resolution topographical information utilizing scanning tunneling and atomic force microscopy, we present new results on the time sequence of events leading up to defect initiation and growth which ultimately leads to fracture. We employ dynamic methods as well as post-fracture examination in polymers, ceramics, metals, and interfaces. We emphasize mechanisms, with interpretation and connections between these results and the creation and evolution of defects in materials under mechanical stress. In many cases, the information we are acquiring has important implications concerning dissipation of energy (e.g., plastic deformation, microcracking, crack branching, and crack deflection) which play critical roles in controlling the strength and toughness of materials.

  11. Prediction and Verification of Ductile Crack Growth from Simulated Defects in Strength Overmatched Butt Welds

    NASA Technical Reports Server (NTRS)

    Nishioka, Owen S.

    1997-01-01

    Defects that develop in welds during the fabrication process are frequently manifested as embedded flaws from lack of fusion or lack of penetration. Fracture analyses of welded structures must be able to assess the effect of such defects on the structural integrity of weldments; however, the transferability of R-curves measured in laboratory specimens to defective structural welds has not been fully examined. In the current study, the fracture behavior of an overmatched butt weld containing a simulated buried, lack-of-penetration defect is studied. A specimen designed to simulate pressure vessel butt welds is considered; namely, a center crack panel specimen, of 1.25 inch by 1.25 inch cross section, loaded in tension. The stress-relieved double-V weld has a yield strength 50% higher than that of the plate material, and displays upper shelf fracture behavior at room temperature. Specimens are precracked, loaded monotonically while load-CMOD measurements are made, then stopped and heat tinted to mark the extent of ductile crack growth. These measurements are compared to predictions made using finite element analysis of the specimens using the fracture mechanics code Warp3D, which models void growth using the Gurson-Tvergaard dilitant plasticity formulation within fixed sized computational cells ahead of the crack front. Calibrating data for the finite element analyses, namely cell size and initial material porosities are obtained by matching computational predictions to experimental results from tests of welded compact tension specimens. The R-curves measured in compact tension specimens are compared to those obtained from multi-specimen weld tests, and conclusions as to the transferability of R-curves is discussed.

  12. Osteogenic BMPs promote tumor growth of human osteosarcomas that harbor differentiation defects.

    PubMed

    Luo, Xiaoji; Chen, Jin; Song, Wen-Xin; Tang, Ni; Luo, Jinyong; Deng, Zhong-Liang; Sharff, Katie A; He, Gary; Bi, Yang; He, Bai-Cheng; Bennett, Erwin; Huang, Jiayi; Kang, Quan; Jiang, Wei; Su, Yuxi; Zhu, Gao-Hui; Yin, Hong; He, Yun; Wang, Yi; Souris, Jeffrey S; Chen, Liang; Zuo, Guo-Wei; Montag, Anthony G; Reid, Russell R; Haydon, Rex C; Luu, Hue H; He, Tong-Chuan

    2008-12-01

    Osteosarcoma (OS) is the most common primary malignancy of bone. Here, we investigated a possible role of defective osteoblast differentiation in OS tumorigenesis. We found that basal levels of the early osteogenic marker alkaline phosphatase (ALP) activity were low in OS lines. Osteogenic regulators Runx2 and OSX, and the late marker osteopontin (OPN) expressed at low levels in most OS lines, indicating that most OS cells fail to undergo terminal differentiation. Furthermore, OS cells were refractory to osteogenic BMP-induced increases in ALP activity. Osteogenic BMPs were shown to upregulate early target genes, but not late osteogenic markers OPN and osteocalcin (OC). Furthermore, osteogenic BMPs failed to induce bone formation from human OS cells, rather effectively promoted OS tumor growth in an orthotopic OS model. Exogenous expression of early target genes enhanced BMP-stimulated OS tumor growth, whereas osteogenic BMP-promoted OS tumor growth was inhibited by exogenous Runx2 expression. These results suggest that alterations in osteoprogenitors may disrupt osteogenic differentiation pathway. Thus, identifying potential differentiation defects in OS tumors would allow us to reconstruct the tumorigenic events in osteoprogenitors and to develop rational differentiation therapies for clinical OS management. PMID:18838962

  13. Influence of growth temperature on AlGaN multiquantum well point defect incorporation and photoluminescence efficiency

    NASA Astrophysics Data System (ADS)

    Armstrong, A.; Allerman, A. A.; Henry, T. A.; Crawford, M. H.

    2011-04-01

    The dependence of (Al)GaN/AlGaN multiquantum well (MQWs) optical efficiency and defect incorporation on the growth temperature (Tg) of the optically active region was investigated. Marked increase in MQW photoluminescence (PL) intensity was observed for increasing Tg. Correspondingly, increasing Tg also significantly reduced point defect incorporation under QW growth conditions, as determined by deep level optical spectroscopy. It is suggested that enhanced MQW PL with increasing Tg resulted from improved nonradiative lifetime through reduced nonradiative defect density in the MQW region.

  14. Postnatal growth defects in mice with constitutive depletion of central serotonin.

    PubMed

    Narboux-Nême, Nicolas; Angenard, Gaelle; Mosienko, Valentina; Klempin, Friederike; Pitychoutis, Pothitos M; Deneris, Evan; Bader, Michael; Giros, Bruno; Alenina, Natalia; Gaspar, Patricia

    2013-01-16

    Although the trophic actions of serotonin (5-HT) are well established, only few developmental defects have been reported in mouse strains with constitutive hyposerotonergia. We analyzed postnatal growth and cortical development in three different mutant mouse strains with constitutive reductions in central 5-HT levels. We compared two previously published mouse strains with severe (-95%) depletions of 5-HT, the tryptophan hydroxylase (Tph) 2(-/-) mouse line and VMAT2(sert-cre) mice, with a new strain, in which VMAT2 deletion is driven by Pet1 (VMAT2(pet1-cre)) in 5-HT raphe neurons leading to partial (-75%) reduction in brain 5-HT levels. We find that normal embryonic growth and postnatal growth retardation are common features of all these mouse strains. Postnatal growth retardation varied from mild to severe according to the extent of the brain 5-HT reduction and gender. Normal growth was reinstated in VMAT2(sert-cre) mice by reconstituting central 5-HT stores. Growth abnormalities could not be linked to altered food intake or temperature control. Morphological study of the cerebral cortex over postnatal development showed a delayed maturation of the upper cortical layers in the VMAT2(sert-cre) and Tph2(-/-) mice, but not in the VMAT2(pet1-cre) mice. No changes in layer-specific gene expression or morphological alterations of barrel cortex development were found. Overall, these observations sustain the notion that central 5-HT signaling is required for the preweaning growth spurt of mouse pups. Brain development appeared to be immune to severe central 5-HT depletion for its overall growth during prenatal life, whereas reduced brain growth and delayed cortical maturation development occurred during postnatal life. Reduced developmental 5-HT signaling during postnatal development might modulate the function and fine structure of neural circuits in ways that affect adult behavior. PMID:23336056

  15. Growth parameters of Escherichia coli O157:H7, Salmonella spp., Listeria monocytogenes, and aerobic mesophilic bacteria of apple cider amended with nisin-EDTA.

    PubMed

    Ukuku, Dike O; Zhang, Howard; Huang, Lihan

    2009-05-01

    The effect of nisin (0 or 300 IU/mL), ethylenediamine tetraacetic acid (EDTA, 20 mM), and nisin (300 IU)-EDTA (20 mM) on growth parameters, including lag period (LP) and generation time, of Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella spp. in the presence or absence of aerobic mesophilic bacteria of apple cider during storage at 5 degrees C for up to 16 days or 23 degrees C for 16 h was investigated. The growth data were analyzed and fitted to the modified Gompertz model. The LP values for aerobic mesophilic bacteria of apple cider (control) and those amended with EDTA and nisin during storage at 5 degrees C were 1.61, 1.76, and 5.45 days, respectively. In apple cider stored at 23 degrees C for 16 h, the LP values for the same bacteria and treatment were 3.24, 3.56, and 5.85 h, respectively. The LP values for E. coli O157:H7 determined in the presence of aerobic mesophilic bacteria of apple cider stored at 23 degrees C for 16 h was 1.48 h, while populations for L. monocytogenes and Salmonella in the same cider declined. In sterile apple cider left at 23 degrees C for 16 h, the LP values for E. coli O157:H7, Salmonella, and L. monocytogenes averaged 2.74, 2.37, and 3.16 h, respectively. The generation time for these pathogens were 0.402, 0.260, and 0.187 log (CFU/mL)/h, respectively. Addition of nisin and EDTA combination caused a decline in lag phase duration and the populations for all pathogens tested, suggesting possible addition of this additive to freshly prepared apple cider to enhance its microbial safety and prevent costly recalls. PMID:19415973

  16. Growth of Campylobacter incubated aerobically in fumarate-pyruvate media or media supplemented with dairy, meat, or soy extracts and peptones.

    PubMed

    Hinton, Arthur

    2016-09-01

    The ability of Campylobacter to grow aerobically in media supplemented with fumarate-pyruvate or with dairy, meat, or soy extracts or peptones was examined. Optical densities (OD) of Campylobacter cultured in basal media, media supplemented with fumarate-pyruvate or with 1.0, 2.5, 5.0, or 7.5% beef extract was measured. Growth was also compared in media supplemented with other extracts or peptones. Finally, cfu/mL of Campylobacter recovered from basal media or media supplemented with fumarate-pyruvate, casamino acids, beef extract, soytone, or beef extract and soytone was determined. Results indicated that OD of cultures grown in media supplemented with fumarate-pyruvate or with 5.0 or 7.5% beef extract were higher than OD of isolates grown in basal media or media supplemented with lower concentrations of beef extract. Highest OD were produced by isolates grown in media supplemented with beef extract, peptone from meat, polypeptone, proteose peptone, or soytone. Also, more cfu/mL were recovered from media with fumarate-pyruvate, beef extract, soytone, or beef extract-soytone than from basal media or media with casamino acids. Findings indicate that media supplemented with organic acids, vitamins, and minerals and media supplemented with extracts or peptones containing these metabolites can support aerobic growth of Campylobacter. PMID:27217355

  17. Terminal Oxidases of Bacillus subtilis Strain 168: One Quinol Oxidase, Cytochrome aa3 or Cytochrome bd, Is Required for Aerobic Growth

    PubMed Central

    Winstedt, Lena; von Wachenfeldt, Claes

    2000-01-01

    The gram-positive endospore-forming bacterium Bacillus subtilis has, under aerobic conditions, a branched respiratory system comprising one quinol oxidase branch and one cytochrome oxidase branch. The system terminates in one of four alternative terminal oxidases. Cytochrome caa3 is a cytochrome c oxidase, whereas cytochrome bd and cytochrome aa3 are quinol oxidases. A fourth terminal oxidase, YthAB, is a putative quinol oxidase predicted from DNA sequence analysis. None of the terminal oxidases are, by themselves, essential for growth. However, one quinol oxidase (cytochrome aa3 or cytochrome bd) is required for aerobic growth of B. subtilis strain 168. Data indicating that cytochrome aa3 is the major oxidase used by exponentially growing cells in minimal and rich medium are presented. We show that one of the two heme-copper oxidases, cytochrome caa3 or cytochrome aa3, is required for efficient sporulation of B. subtilis strain 168 and that deletion of YthAB in a strain lacking cytochrome aa3 makes the strain sporulation deficient. PMID:11073895

  18. Defect structures before steady-state void growth in austenitic stainless steels

    NASA Astrophysics Data System (ADS)

    Yoshiie, T.; Sato, K.; Cao, X.; Xu, Q.; Horiki, M.; Troev, T. D.

    2012-10-01

    In the radiation damage process of austenitic stainless steels, there exists an incubation period before steady-state void growth, and the defect formation behaviors during that period strongly depend on alloy composition. Using the technique of positron annihilation lifetime measurement, the evolution of defect clusters during the incubation period in neutron, electron, and H-ion irradiations was studied for a variety of austenitic stainless steels including commercial and model alloys. The lifetime measurements indicated that in fission neutron irradiation to 0.2 dpa at 363 K, single vacancies were predominantly formed in the commercial alloys, SUS316L and Ti added, modified SUS316, while large voids were formed in Ni and Fe-Cr-Ni. After neutron irradiation at 573 K, stacking fault tetrahedra and/or precipitates were detected in the commercial alloys, while large voids were detected in the model alloys. In the 30 MeV electron irradiation to a dose of 0.012 dpa, the effect of alloying elements on lifetime data was less significant at 353 K, but a significant difference was found between model alloys and commercial alloys at 573 K. The H-ion irradiation at 2 MeV was also performed at room temperature. Defect evolution during the incubation period is discussed on the basis of the neutron, electron and H-ion irradiation results.

  19. The Detached Bridgman Process: Application for the Growth of Low-Defect Germanium Crystals

    NASA Technical Reports Server (NTRS)

    Schweizer, M.; Volz, M. P.; Cobb, S. D.; Croell, A.; Dold, P.; Szofran, F. R.; Curreri, Peter A. (Technical Monitor)

    2002-01-01

    During crystal growth in the vertical Bridgman process, both the melt and the growing crystal are in contact with the ampoule wall. The different thermal coefficients of expansion of the crystal and the ampoule wall can lead to stresses, crystal defects, and not rarely to cracks and/or polycrystalline growth in the crystal. The detached Bridgman process is characterized by the fact that the melt meniscus frees itself from the ampoule wall and the crystal can be grown without wall contact with the ampoule. After the effect of detachment was observed due to the reduced force of gravity during the early experiments under microgravity conditions, in the past few years the Bridgman process likewise has been successfully used to grow at least partially detached under 1g-condition. If the requirements for detaching the melt meniscus from the ampoule wall are not fulfilled by the material-specific parameters (like e.g. wetting behavior between ampoule and melt and the growth angle of the crystal), detachment can be obtained also by the imposition of suitable pressure ratios in the growth ampoule. In the context of this paper, the growth of germanium by the detached and vertical Bridgman processes in pyrolytic boron nitride crucibles will be reported, Typical gap widths between ampoule wall and detached grown crystals are approximately 10-50 microns. Compared to the crystals grown with wall contact, a reduction of the etch pit density of approximately two orders of magnitude could be obtained by growing with the detached process.

  20. Deletion of the carbonic anhydrase-like gene NCE103 of the yeast Saccharomyces cerevisiae causes an oxygen-sensitive growth defect.

    PubMed

    Götz, R; Gnann, A; Zimmermann, F K

    1999-07-01

    The yeast protein Nce103p encoded by the gene NCE103 (YNL036w) was described by Cleves et al. (1996) as a substrate of the non-classical export pathway which acts independently of the classical pathway through the ER and the Golgi compartments. However, the predicted amino acid sequence of Nce103p shows high levels of identities to carbonic anhydrases of pro- and eukaryotes. A nce103-Delta deletion strain did not grow on a rich peptone-yeast extract-glucose medium under normal aerobic conditions at pH values of 3.0-8.0, but grew like wild-type in an oxygen-free nitrogen or oxygen-reduced atmosphere over this pH range, and was more sensitive to H(2)O(2) than wild-type. No carbonic anhydrase activity could be detected in crude extracts prepared from wild-type, nce103-Delta mutants or in strains transformed with a multicopy plasmid carrying the NCE103 gene. Expression of the Medicago sativa carbonic anhydrase gene (Coba de la Peña et al., 1997), in a yeast expression cassette on a multicopy plasmid, complemented the growth defects caused by the nce103-Delta deletion and carbonic anhydrase activity could be readily detected in the crude extract. The ability of the nce103-Delta deletion strain to grow like wild-type under anaerobic conditions suggests that the protein encoded by NCE103 is required for protection against certain products of an oxidative metabolism and can be replaced in this function by the Medicago sativa carbonic anhydrase. A NCE103 promoter-LacZ fusion in a wild-type background showed that NCE103 is poorly transcribed under aerobic conditions and at an undetectable level under anaerobic conditions. PMID:10407265

  1. Study of defect management in the growth of semipolar (11-22) GaN on patterned sapphire

    NASA Astrophysics Data System (ADS)

    Vennéguès, P.; Tendille, F.; De Mierry, P.

    2015-08-01

    This work describes, using mainly transmission electron microscopy as an investigation tool, the nature and behaviour of the crystalline defects which are present in (11-22) semipolar GaN films grown epitaxially on patterned r-sapphire substrates using a 3 step growth process. The microstructure at these different growth stages is described. The independent 3D-crystallites nucleated on the substrate surface contain threading dislocations resulting from the epitaxy on c-sapphire facets and basal stacking faults (BSFs), mainly in the  -c-wings. These defects are concentrated in a few hundred nanometre wide stripe-like regions emerging on the top facet of the islands. By a careful choice of the growth conditions, these defective regions may be overgrown by defect-free material, blocking their propagation towards the coalesced surface. However, when the 3D crystals coalesce, new dislocations together with very few BSFs are created at the coalescence boundaries. These coalescence defects propagate to the surface of the films in (0001) planes. In summary, the control of the nucleation and propagation of the crystalline defects allows obtaining large area semipolar films with very low defect densities: 7   ×   107 cm-2 for TDs and 70 cm-1 for BSFs.

  2. Development of a predictive model for the growth kinetics of aerobic microbial population on pomegranate marinated chicken breast fillets under isothermal and dynamic temperature conditions.

    PubMed

    Lytou, Anastasia; Panagou, Efstathios Z; Nychas, George-John E

    2016-05-01

    The aim of this study was the development of a model to describe the growth kinetics of aerobic microbial population of chicken breast fillets marinated in pomegranate juice under isothermal and dynamic temperature conditions. Moreover, the effect of pomegranate juice on the extension of the shelf life of the product was investigated. Samples (10 g) of chicken breast fillets were immersed in marinades containing pomegranate juice for 3 h at 4 °C following storage under aerobic conditions at 4, 10, and 15 °C for 10 days. Total Viable Counts (TVC), Pseudomonas spp and lactic acid bacteria (LAB) were enumerated, in parallel with sensory assessment (odor and overall appearance) of marinated and non-marinated samples. The Baranyi model was fitted to the growth data of TVC to calculate the maximum specific growth rate (μmax) that was further modeled as a function of temperature using a square root-type model. The validation of the model was conducted under dynamic temperature conditions based on two fluctuating temperature scenarios with periodic changes from 6 to 13 °C. The shelf life was determined both mathematically and with sensory assessment and its temperature dependence was modeled by an Arrhenius type equation. Results showed that the μmax of TVC of marinated samples was significantly lower compared to control samples regardless temperature, while under dynamic temperature conditions the model satisfactorily predicted the growth of TVC in both control and marinated samples. The shelf-life of marinated samples was significantly extended compared to the control (5 days extension at 4 °C). The calculated activation energies (Ea), 82 and 52 kJ/mol for control and marinated samples, respectively, indicated higher temperature dependence of the shelf life of control samples compared to marinated ones. The present results indicated that pomegranate juice could be used as an alternative ingredient in marinades to prolong the shelf life of chicken. PMID:26742613

  3. Atomically flat areas on silicon (001) and (111): Fabrication by evaporation or growth and defect characterization

    NASA Astrophysics Data System (ADS)

    Lee, Doohan

    As the dimensions of devices such as field effect transistors, optical devices and layered quantum well structures are decreased, it may be critical to have surfaces and interfaces that are extremely smooth and have no atomic steps at those locations on a wafer where devices will be fabricated and to understand the characteristics of those surfaces. For this work, we have eliminated the atomic steps on Si(111) and Si(001) vicinal surfaces by high temperature annealing and epitaxial growth in the step flow regime on patterned Si substrates with ridges and mesas respectively. In both the annealing and growth cases, the characteristics of the step clearing process as well as the stability of the step free areas are different for Si(111) and Si(001). It is more difficult to make step free regions on Si(001) than on Si(111) mainly due to the smaller adatom diffusivity on Si(001). Excessive annealing (or growth) on large step free areas leads to the formation of circular vacancy pits (or adatom islands). Anisotropic surface diffusion and stress on Si(001) due to the (1 x 2) and (2 x 1) reconstructions lead to interesting step distributions on quenched and slowly cooled Si(001) surfaces which are initially step free. Quenching experiments can give information about the nature and concentrations of point defects on the step free terraces. The result of the quenching experiments are very dependent on quenching conditions such as quenching rate, applied stress, and temperature from which the samples are quenched. The quenched Si(111) surfaces may exhibit some degree of disorder in the reconstructed regions or island formation. A series of experiments have been performed to try to relate the room temperature observations to the defect characteristics at high temperature.

  4. Structural defect induced peak splitting in gold-copper bimetallic nanorods during growth by single particle spectroscopy.

    PubMed

    Thota, Sravan; Chen, Shutang; Zhou, Yadong; Zhang, Yong; Zou, Shengli; Zhao, Jing

    2015-09-21

    A single particle level study of bimetallic nanoparticle growth provides valuable information that is usually hidden in ensemble measurements, helping to improve the understanding of a reaction mechanism and overcome the synthetic challenges. In this study, we use single particle spectroscopy to monitor the changes in the scattering spectra of Au-Cu alloy nanorods during growth. We found that the unique features of the single particle scattering spectra were due to atomic level geometric defects in the nanorods. Electrodynamics simulations have demonstrated that small structural defects of a few atomic layers split the scattering peaks, giving rise to higher order modes, which do not exist in defect-free rods of similar geometry. The study shows that single particle scattering technique is as sensitive as high-resolution electron microscopy in revealing atomic level structural defects. PMID:26268683

  5. Structural defect induced peak splitting in gold-copper bimetallic nanorods during growth by single particle spectroscopy

    NASA Astrophysics Data System (ADS)

    Thota, Sravan; Chen, Shutang; Zhou, Yadong; Zhang, Yong; Zou, Shengli; Zhao, Jing

    2015-08-01

    A single particle level study of bimetallic nanoparticle growth provides valuable information that is usually hidden in ensemble measurements, helping to improve the understanding of a reaction mechanism and overcome the synthetic challenges. In this study, we use single particle spectroscopy to monitor the changes in the scattering spectra of Au-Cu alloy nanorods during growth. We found that the unique features of the single particle scattering spectra were due to atomic level geometric defects in the nanorods. Electrodynamics simulations have demonstrated that small structural defects of a few atomic layers split the scattering peaks, giving rise to higher order modes, which do not exist in defect-free rods of similar geometry. The study shows that single particle scattering technique is as sensitive as high-resolution electron microscopy in revealing atomic level structural defects.A single particle level study of bimetallic nanoparticle growth provides valuable information that is usually hidden in ensemble measurements, helping to improve the understanding of a reaction mechanism and overcome the synthetic challenges. In this study, we use single particle spectroscopy to monitor the changes in the scattering spectra of Au-Cu alloy nanorods during growth. We found that the unique features of the single particle scattering spectra were due to atomic level geometric defects in the nanorods. Electrodynamics simulations have demonstrated that small structural defects of a few atomic layers split the scattering peaks, giving rise to higher order modes, which do not exist in defect-free rods of similar geometry. The study shows that single particle scattering technique is as sensitive as high-resolution electron microscopy in revealing atomic level structural defects. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr03979g

  6. Defective Ca2+ metabolism in Duchenne muscular dystrophy: effects on cellular and viral growth.

    PubMed Central

    Fingerman, E; Campisi, J; Pardee, A B

    1984-01-01

    Normal fibroblasts in medium containing 0.02 mM CaCl2 arrested growth within 24 hr, whereas Duchenne muscular dystrophy fibroblasts continued to grow for 5 days, albeit at 40% of their rate in standard medium (1.8 mM CaCl2). Moreover, Duchenne cells in calcium-deficient medium showed an enhanced rate of protein synthesis (60% over the rate in standard medium), whereas normal cells were unaffected. Previously we described a general assay for detection of mutant cells by using herpes simplex virus I replication as a probe of cellular function. By altering the growth medium, one can elicit changes in viral DNA replication that depend upon cellular differences. Duchenne fibroblasts in calcium-deficient low-serum (0.5%) medium supported viral replication at a rate 7- to 10-fold greater than did normal cells infected under the same conditions. Using this viral assay, we have successfully identified all 10 samples of a blind coded set of Duchenne muscular dystrophy, normal, and heterozygote cells. In addition, differences of a lower magnitude were found between these cell strains as measured by cellular growth or protein synthesis. Therefore, a cell's ability to grow and support viral replication in calcium-deficient medium can be used to readily distinguish Duchenne muscular dystrophy fibroblasts from normal ones. These results suggest that the viral assay could be used as a prenatal diagnostic test. A defect related to calcium metabolism may be fundamental to this disease. PMID:6095311

  7. THE BISPHOSPHONATE ZOLEDRONIC ACID DECREASES TUMOR GROWTH IN BONE IN MICE WITH DEFECTIVE OSTEOCLASTS*

    PubMed Central

    Hirbe, Angela C.; Roelofs, Anke J.; Floyd, Desiree H.; Deng, Hongju; Becker, Stephanie N.; Lanigan, Lisa G.; Apicelli, Anthony J.; Xu, Zhiqiang; Prior, Julie L.; Eagleton, Mark C.; Piwnica-Worms, David; Rogers, Michael J.; Weilbaecher, Katherine

    2009-01-01

    Bisphosphonates (BPs), bone targeted drugs that disrupt osteoclast function, are routinely used to treat complications of bone metastasis. Studies in preclinical models of cancer have shown that BPs reduce skeletal tumor burden and increase survival. Similarly, we observed in the present study that administration of the Nitrogen-containing BP (N-BP), zoledronic acid (ZA) to osteolytic tumor-bearing Tax+ mice beginning at 6 months of age led to resolution of radiographic skeletal lesions. N-BPs inhibit farnesyl diphosphate (FPP) synthase, thereby inhibiting protein prenylation and causing cellular toxicity. We found that ZA decreased Tax+ tumor and B16 melanoma viability and caused the accumulation of unprenylated Rap1a proteins in vitro. However, it is presently unclear whether N-BPs exert anti-tumor effects in bone independent of inhibition of osteoclast (OC) function in vivo. Therefore, we evaluated the impact of treatment with ZA on B16 melanoma bone tumor burden in irradiated mice transplanted with splenic cells from src-/- mice, which have non-functioning OCs. OC-defective mice treated with ZA demonstrated a significant 88% decrease in tumor growth in bone compared to vehicle-treated OC-defective mice. These data support an osteoclast-independent role for N-BP therapy in bone metastasis. PMID:19442620

  8. The influence of defects and impurities on the nucleation and growth of oriented films by evaporation

    NASA Technical Reports Server (NTRS)

    Green, A. K.

    1973-01-01

    The influence of substrate imperfections on the nucleation and growth of fcc metals on alkali halides is discussed. Films deposited on well characterized substrated under well defined vacuum evaporation conditions are investigated. The experimental results of this work are correlated with similar work by other investigators. Models which have been proposed by various authors to explain experimental results are critically examined and areas of difficulty are pointed out. The influence of defects on nucleation rate and the orientation of the film is emphasized. Specific examples of impurity effects, irradiation effects and the influence of amorphous layers are discussed in detail. Evidence is shown that the formation of multiply twinned particles is a result of coalescence and growth. The only consistent model for the orienting influence of impurities is shown to be a chemical reaction effect. It is demonstrated that an alkali metal impurity is very likely responsible for the orienting influence of both water vapor exposure and irradiation. A negative result is found for the reported possibility of an orienting influence being transmitted through an amorphous layer.

  9. Structural gene for beta-nerve growth factor not defective in familial dysautonomia.

    PubMed Central

    Breakefield, X O; Orloff, G; Castiglione, C; Coussens, L; Axelrod, F B; Ullrich, A

    1984-01-01

    The developmental loss of neurons in sympathetic, sensory, and some parasympathetic ganglia in familial dysautonomia suggests an inherited defect in the action of beta-nerve growth factor (beta-NGF). The role of this growth factor in dysautonomia has been difficult to resolve as there is no known source of authentic human beta-NGF. The availability of a cloned DNA probe for the human beta-NGF gene has allowed identification of some copies of the gene (alleles) in six affected families. Alleles differ in the length of restriction endonuclease fragments that hybridize to DNA probes for the gene. In two families, affected children did not inherit the same two alleles at the beta-NGF locus. Since this disease is transmitted in an autosomal recessive manner, affected children must share the same alleles at the locus causing the disease. This analysis excludes the beta-NGF gene region as the cause of this neurologic disease but does not eliminate other genes involved in beta-NGF action, such as those coding for processing enzymes, receptors, or other subunits of the NGF complex. Images PMID:6330750

  10. Defective Kernel 1 (DEK1) is required for three-dimensional growth in Physcomitrella patens

    PubMed Central

    Perroud, Pierre-François; Demko, Viktor; Johansen, Wenche; Wilson, Robert C; Olsen, Odd-Arne; Quatrano, Ralph S

    2014-01-01

    Orientation of cell division is critical for plant morphogenesis. This is evident in the formation and function of meristems and for morphogenetic transitions. Mosses undergo such transitions: from two-dimensional tip-growing filaments (protonema) to the generation of three-dimensional leaf-like structures (gametophores). The Defective Kernel 1 (DEK1) protein plays a key role in the perception of and/or response to positional cues that specify the formation and function of the epidermal layer in developing seeds of flowering plants. The moss Physcomitrella patens contains the highly conserved DEK1 gene. Using efficient gene targeting, we generated a precise PpDEK1 deletion (Δdek1), which resulted in normal filamentous growth of protonema. Two distinct mutant phenotypes were observed: an excess of buds on the protonema, and abnormal cell divisions in the emerging buds resulting in developmental arrest and the absence of three-dimensional growth. Overexpression of a complete PpDEK1 cDNA, or the calpain domain of PpDEK1 alone, successfully complements both phenotypes. These results in P. patens demonstrate the morphogenetic importance of the DEK1 protein in the control of oriented cell divisions. As it is not for protonema, it will allow dissection of the structure/function relationships of the different domains of DEK1 using gene targeting in null mutant background. PMID:24844771

  11. An Alginate-based Hybrid System for Growth Factor Delivery in the Functional Repair of Large Bone Defects

    PubMed Central

    Kolambkar, Yash M.; Dupont, Kenneth M.; Boerckel, Joel D.; Huebsch, Nathaniel; Mooney, David J.; Hutmacher, Dietmar W.

    2010-01-01

    The treatment of challenging fractures and large osseous defects presents a formidable problem for orthopaedic surgeons. Tissue engineering/regenerative medicine approaches seek to solve this problem by delivering osteogenic signals within scaffolding biomaterials. In this study, we introduce a hybrid growth factor delivery system that consists of an electrospun nanofiber mesh tube for guiding bone regeneration combined with peptide-modified alginate hydrogel injected inside the tube for sustained growth factor release. We tested the ability of this system to deliver recombinant bone morphogenetic protein-2 (rhBMP-2) for the repair of critically-sized segmental bone defects in a rat model. Longitudinal μ-CT analysis and torsional testing provided quantitative assessment of bone regeneration. Our results indicate that the hybrid delivery system resulted in consistent bony bridging of the challenging bone defects. However, in the absence of rhBMP-2, the use of nanofiber mesh tube and alginate did not result in substantial bone formation. Perforations in the nanofiber mesh accelerated the rhBMP-2 mediated bone repair, and resulted in functional restoration of the regenerated bone. μ-CT based angiography indicated that perforations did not significantly affect the revascularization of defects, suggesting that some other interaction with the tissue surrounding the defect such as improved infiltration of osteoprogenitor cells contributed to the observed differences in repair. Overall, our results indicate that the hybrid alginate/nanofiber mesh system is a promising growth factor delivery strategy for the repair of challenging bone injuries. PMID:20864165

  12. Delivery of growth factors using a smart porous nanocomposite scaffold to repair a mandibular bone defect.

    PubMed

    Liu, Xian; Zhao, Kun; Gong, Tao; Song, Jian; Bao, Chongyun; Luo, En; Weng, Jie; Zhou, Shaobing

    2014-03-10

    Implantation of a porous scaffold with a large volume into the body in a convenient and safe manner is still a challenging task in the repair of bone defects. In this study, we present a porous smart nanocomposite scaffold with a combination of shape memory function and controlled delivery of growth factors. The shape memory function enables the scaffold with a large volume to be deformed into its temporal architecture with a small volume using hot-compression and can subsequently recover its original shape upon exposure to body temperature after it is implanted in the body. The scaffold consists of chemically cross-linked poly(ε-caprolactone) (c-PCL) and hydroxyapatite nanoparticles. The highly interconnected pores of the scaffold were obtained using the sugar leaching method. The shape memory porous scaffold loaded with bone morphogenetic protein-2 (BMP-2) was also fabricated by coating the calcium alginate layer and BMP-2 on the surface of the pore wall. Under both in vitro and in vivo environmental conditions, the porous scaffold displays good shape memory recovery from the compressed shape with deformed pores of 33 μm in diameter to recover its porous shape with original pores of 160 μm in diameter. In vitro cytotoxicity based on the MTT test revealed that the scaffold exhibited good cytocompatibility. The in vivo micro-CT and histomorphometry results demonstrated that the porous scaffold could promote new bone generation in the rabbit mandibular bone defect. Thus, our results indicated that this shape memory porous scaffold demonstrated great potential for application in bone regenerative medicine. PMID:24467335

  13. Early defect of transforming growth factor β1 formation in Huntington’s disease

    PubMed Central

    Battaglia, Giuseppe; Cannella, Milena; Riozzi, Barbara; Orobello, Sara; Maat-Schieman, Marion L; Aronica, Eleonora; Busceti, Carla Letizia; Ciarmiello, Andrea; Alberti, Silvia; Amico, Enrico; Sassone, Jenny; Sipione, Simonetta; Bruno, Valeria; Frati, Luigi; Nicoletti, Ferdinando; Squitieri, Ferdinando

    2011-01-01

    Abstract A defective expression or activity of neurotrophic factors, such as brain- and glial-derived neurotrophic factors, contributes to neuronal damage in Huntington’s disease (HD). Here, we focused on transforming growth factor-β (TGF-β1), a pleiotropic cytokine with an established role in mechanisms of neuroprotection. Asymptomatic HD patients showed a reduction in TGF-β1 levels in the peripheral blood, which was related to trinucleotide mutation length and glucose hypometabolism in the caudate nucleus. Immunohistochemical analysis in post-mortem brain tissues showed that TGF-β1 was reduced in cortical neurons of asymptomatic and symptomatic HD patients. Both YAC128 and R6/2 HD mutant mice showed a reduced expression of TGF-β1 in the cerebral cortex, localized in neurons, but not in astrocytes. We examined the pharmacological regulation of TGF-β1 formation in asymptomatic R6/2 mice, where blood TGF-β1 levels were also reduced. In these R6/2 mice, both the mGlu2/3 metabotropic glutamate receptor agonist, LY379268, and riluzole failed to increase TGF-β1 formation in the cerebral cortex and corpus striatum, suggesting that a defect in the regulation of TGF-β1 production is associated with HD. Accordingly, reduced TGF-β1 mRNA and protein levels were found in cultured astrocytes transfected with mutated exon 1 of the human huntingtin gene, and in striatal knock-in cell lines expressing full-length huntingtin with an expanded glutamine repeat. Taken together, our data suggest that serum TGF-β1 levels are potential biomarkers of HD development during the asymptomatic phase of the disease, and raise the possibility that strategies aimed at rescuing TGF-β1 levels in the brain may influence the progression of HD. PMID:20082658

  14. Identification and Control of Gravity Related Defect Formation During Melt Growth of Bismuth-Silicate (Bi12SiO20)

    NASA Technical Reports Server (NTRS)

    Zheng, Y.; Witt, A. F.

    1999-01-01

    In the light of strong indications that a majority of critical defects formed in bismuth silicon oxide (BSO) during growth from the melt is related directly or indirectly to gravitational interference, it is suggested to use the reduced gravity environment of outer space for experimentation directed at the identification and control of these defects. The results of these experiments are expected to lead to advances in our understanding of crystal growth related defect formation in general and will establish a basis for effective defect engineering, the approach to efficient achievement of defect related, application specific properties in opto-electronic materials

  15. Growth, nutritional, and gastrointestinal aspects of ankyloblepharon-ectodermal defect-cleft lip and/or palate (AEC) syndrome

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ankyloblepharon-ectodermal defect-cleft lip and/or palate (AEC), is a rare genetic disorder due to mutations in the TP63 gene. In the present study, we characterized the pattern of growth and body composition, and the nutritional and gastrointestinal aspects of children and adults (n = 18) affected ...

  16. Growth Retardation, DNA Repair Defects, and Lack of Spermatogenesis in BRCA1-Deficient Mice

    PubMed Central

    Cressman, Victoria L.; Backlund, Dana C.; Avrutskaya, Anna V.; Leadon, Steven A.; Godfrey, Virginia; Koller, Beverly H.

    1999-01-01

    BRCA1 is a nuclear phosphoprotein expressed in a broad spectrum of tissues during cell division. The inheritance of a mutant BRCA1 allele dramatically increases a woman’s lifetime risk for developing both breast and ovarian cancers. A number of mouse lines carrying mutations in the Brca1 gene have been generated, and mice homozygous for these mutations generally die before day 10 of embryonic development. We report here the survival of a small number of mice homozygous for mutations in both the p53 and Brca1 genes. The survival of these mice is likely due to additional unknown mutations or epigenetic effects. Analysis of the Brca1−/− p53−/− animals indicates that BRCA1 is not required for the development of most organ systems. However, these mice are growth retarded, males are infertile due to meiotic failure, and the mammary gland of the female mouse is underdeveloped. Growth deficiency due to loss of BRCA1 was more thoroughly examined in an analysis of primary fibroblast lines obtained from these animals. Like p53−/− fibroblasts, Brca1−/− p53−/− cells proliferate more rapidly than wild-type cells; however, a high level of cellular death in these cultures results in reduced overall growth rates in comparison to p53−/− fibroblasts. Brca1−/− p53−/− fibroblasts are also defective in transcription-coupled repair and display increased sensitivity to DNA-damaging agents. We show, however, that after continued culture, and perhaps accelerated by the loss of BRCA1 repair functions, populations of Brca1−/− p53−/− fibroblasts with increased growth rates can be isolated. The increased survival of BRCA1-deficient fibroblasts in the absence of p53, and with the subsequent accumulation of additional growth-promoting changes, may mimic the events that occur during malignant transformation of BRCA1-deficient epithelia. PMID:10490643

  17. Effect of semisynthetic extracellular matrix-like hydrogel containing hepatocyte growth factor on repair of femoral neck defect in rabbits.

    PubMed

    Liu, Pengfei; Guo, Lin; Huang, Lanfeng; Zhao, Dewei; Zhen, Ruixin; Hu, Xiaoning; Yuan, Xiaolin

    2015-01-01

    Using tissue engineering technology research to develop organized artificial bone, then repair bone defect. This work aims to investigate the role of semisynthetic extracellular matrix-like hydrogel (sECMH) containing hepatocyte growth factor (HGF) on repair of femoral neck defect in rabbits. 18 New Zealand rabbits were used in this study. According to autologous paired comparison method, the left and right sides of rabbit were used as control and experimental side, respectively. The models of bilateral femoral neck bone defect were established. In experimental side, sECMH containing HGF was implanted in the defect area. In control side, no material was implanted in the defect area. At the 2nd, 4th and 8th week after surgery, the gross observation, histological examination and molybdenum target (Mo-target) X-ray examination were performed on the specimens to study the repair of femoral neck defect. In gross observation, there was no macroscopic difference of femoral neck specimen between the 2nd and 4th postoperative week. At the 8th week, the defect orifice was closed with immature cortical bone, with unblocked marrow cavity. HE staining results showed that, at the 4th week, there were more new vessels in defect area of experimental side, compared with control side. At the 8th week, in experimental side there was immature cortical bone connecting the fracture end in defect area, with visible bone marrow cells. Mo-target X-ray examination found that, at the 8th week, the bone tissue repair in experimental side was better than control side. As a new drug delivery system, sECMH containing HGF has good application prospect in bone tissue repair. PMID:26221278

  18. Stable Pseudohyphal Growth in Budding Yeast Induced by Synergism between Septin Defects and Altered MAP-kinase Signaling

    PubMed Central

    Kim, Junwon; Rose, Mark D.

    2015-01-01

    Upon nutrient limitation, budding yeasts like Saccharomyces cerevisiae can be induced to adopt alternate filament-like growth patterns called diploid pseudohyphal or invasive haploid growth. Here, we report a novel constitutive pseudohyphal growth state, sharing some characteristics with classic forms of filamentous growth, but differing in crucial aspects of morphology, growth conditions and genetic regulation. The constitutive pseudohyphal state is observed in fus3 mutants containing various septin assembly defects, which we refer to as sadF growth (septin assembly defect induced filamentation) to distinguish it from classic filamentation pathways. Similar to other filamentous states, sadF cultures comprise aggregated chains of highly elongated cells. Unlike the classic pathways, sadF growth occurs in liquid rich media, requiring neither starvation nor the key pseudohyphal proteins, Flo8p and Flo11p. Moreover sadF growth occurs in haploid strains of S288C genetic background, which normally cannot undergo pseudohyphal growth. The sadF cells undergo highly polarized bud growth during prolonged G2 delays dependent on Swe1p. They contain septin structures distinct from classical pseudo-hyphae and FM4-64 labeling at actively growing tips similar to the Spitzenkörper observed in true hyphal growth. The sadF growth state is induced by synergism between Kss1p-dependent signaling and septin assembly defects; mild disruption of mitotic septins activates Kss1p-dependent gene expression, which exacerbates the septin defects, leading to hyper-activation of Kss1p. Unlike classical pseudo-hyphal growth, sadF signaling requires Ste5, Ste4 and Ste18, the scaffold protein and G-protein β and γ subunits from the pheromone response pathway, respectively. A swe1 mutation largely abolished signaling, breaking the positive feedback that leads to amplification of sadF signaling. Taken together, our findings show that budding yeast can access a stable constitutive pseudohyphal growth

  19. Stable Pseudohyphal Growth in Budding Yeast Induced by Synergism between Septin Defects and Altered MAP-kinase Signaling.

    PubMed

    Kim, Junwon; Rose, Mark D

    2015-12-01

    Upon nutrient limitation, budding yeasts like Saccharomyces cerevisiae can be induced to adopt alternate filament-like growth patterns called diploid pseudohyphal or invasive haploid growth. Here, we report a novel constitutive pseudohyphal growth state, sharing some characteristics with classic forms of filamentous growth, but differing in crucial aspects of morphology, growth conditions and genetic regulation. The constitutive pseudohyphal state is observed in fus3 mutants containing various septin assembly defects, which we refer to as sadF growth (septin assembly defect induced filamentation) to distinguish it from classic filamentation pathways. Similar to other filamentous states, sadF cultures comprise aggregated chains of highly elongated cells. Unlike the classic pathways, sadF growth occurs in liquid rich media, requiring neither starvation nor the key pseudohyphal proteins, Flo8p and Flo11p. Moreover sadF growth occurs in haploid strains of S288C genetic background, which normally cannot undergo pseudohyphal growth. The sadF cells undergo highly polarized bud growth during prolonged G2 delays dependent on Swe1p. They contain septin structures distinct from classical pseudo-hyphae and FM4-64 labeling at actively growing tips similar to the Spitzenkörper observed in true hyphal growth. The sadF growth state is induced by synergism between Kss1p-dependent signaling and septin assembly defects; mild disruption of mitotic septins activates Kss1p-dependent gene expression, which exacerbates the septin defects, leading to hyper-activation of Kss1p. Unlike classical pseudo-hyphal growth, sadF signaling requires Ste5, Ste4 and Ste18, the scaffold protein and G-protein β and γ subunits from the pheromone response pathway, respectively. A swe1 mutation largely abolished signaling, breaking the positive feedback that leads to amplification of sadF signaling. Taken together, our findings show that budding yeast can access a stable constitutive pseudohyphal growth

  20. An in vivo study on the effect of scaffold geometry and growth factor release on the healing of bone defects.

    PubMed

    Yilgor, P; Yilmaz, G; Onal, M B; Solmaz, I; Gundogdu, S; Keskil, S; Sousa, R A; Reis, R L; Hasirci, N; Hasirci, V

    2013-09-01

    The hypothesis of this study was that the extent of bone regeneration could be enhanced by using scaffolds with appropriate geometry, and that such an effect could be further increased by mimicking the natural timing of appearance of bone morphogenetic proteins BMP-2 and BMP-7 after fracture. Bioplotted poly(ε-caprolactone) (PCL) disks with four different fibre organizations were used to study the effect of 3D scaffold architecture on the healing of bone defects in a rat pelvis model. Moreover, one PCL construct was further modified by introducing a nanoparticulate sequential BMP-2/BMP-7 delivery system into this scaffold. Scaffolds and functionalized construct along with free nanocapsules were implanted using a rat iliac crest defect model. Six weeks post-implantation, the defects were evaluated by CT scan and histology. Analysis revealed that the basic architecture, having the highest pore volume for tissue ingrowth, presented the highest bone formation as determined by the bone mineral density (BMD) within the defect (144.2 ± 7.1); about four-fold higher than that of the empty defect (34.9 ± 10.7). It also showed the highest histological analysis scores with a high amount of bone formation within the defect, within the scaffold pores and along the outer surfaces of the scaffold. The basic scaffold carrying the BMP-2/BMP-7 delivery system showed significantly higher bone formation than the growth factor-free basic scaffold at 6 weeks (BMD 206.8 ± 15.7). Histological analysis also revealed new bone formation in close to or in direct contact with the construct interface. This study indicates the importance of open and interconnecting pore geometry on the better healing of bone defects, and that this effect could be further increased by supplying growth factors, as is the case in nature. PMID:22396311

  1. Influence of growth temperature and temperature ramps on deep level defect incorporation in m-plane GaN

    NASA Astrophysics Data System (ADS)

    Armstrong, A. M.; Kelchner, K.; Nakamura, S.; DenBaars, S. P.; Speck, J. S.

    2013-12-01

    The dependence of deep level defect incorporation in m-plane GaN films grown by metal-organic chemical vapor deposition on bulk m-plane GaN substrates as a function of growth temperature (Tg) and Tg ramping method was investigated using deep level optical spectroscopy. Understanding the influence of Tg on GaN deep level incorporation is important for InGaN/GaN multi-quantum well (MQW) light emitting diodes (LEDs) and laser diodes (LDs) because GaN quantum barrier (QB) layers are grown much colder than thin film GaN to accommodate InGaN QW growth. Deep level spectra of low Tg (800 °C) GaN films grown under QB conditions were compared to deep level spectra of high Tg (1150 °C) GaN. Reducing Tg, increased the defect density significantly (>50×) through introduction of emergent deep level defects at 2.09 eV and 2.9 eV below the conduction band minimum. However, optimizing growth conditions during the temperature ramp when transitioning from high to low Tg substantially reduced the density of these emergent deep levels by approximately 40%. The results suggest that it is important to consider the potential for non-radiative recombination in QBs of LED or LD active regions, and tailoring the transition from high Tg GaN growth to active layer growth can mitigate such non-radiative channels.

  2. Study on micro-crystallization, growth, optical properties and defects of a nonlinear optical crystal: MnHg(SCN) 4

    NASA Astrophysics Data System (ADS)

    Liu, Xitao; Wang, Xinqiang; Sun, Zhihua; Lin, Xiaojing; Zhang, Guanghui; Xu, Dong

    2011-02-01

    High optical quality single crystals of a nonlinear optical material, manganese mercury thiocyanate, MnHg(SCN) 4 (MMTC), with dimensions up to 21×14×13 mm 3 have been grown by the solvent evaporation method. The growth habit of MMTC crystal crystallized under different conditions was investigated by means of micro-crystallization method. Two typical growth morphologies of the crystal were indexed and compared with the morphology deduced from the single crystal structure data. The results show that two novel {1 0 0} and {1 1 2} facets appear during the crystal growth. Powder second harmonic generation and spectral transmittance measurements were also performed. The results indicate that MMTC is phase-matchable and the UV transparency cutoff occurs at 373 nm. Various defects were found in MMTC crystal. Their formation mechanisms and the methods to eliminate these defects are discussed.

  3. Effect of growth temperature on defects in epitaxial GaN film grown by plasma assisted molecular beam epitaxy

    SciTech Connect

    Kushvaha, S. S. Pal, P.; Shukla, A. K.; Joshi, Amish G.; Gupta, Govind; Kumar, M.; Singh, S.; Gupta, Bipin K.; Haranath, D.

    2014-02-15

    We report the effect of growth temperature on defect states of GaN epitaxial layers grown on 3.5 μm thick GaN epi-layer on sapphire (0001) substrates using plasma assisted molecular beam epitaxy. The GaN samples grown at three different substrate temperatures at 730, 740 and 750 °C were characterized using atomic force microscopy and photoluminescence spectroscopy. The atomic force microscopy images of these samples show the presence of small surface and large hexagonal pits on the GaN film surfaces. The surface defect density of high temperature grown sample is smaller (4.0 × 10{sup 8} cm{sup −2} at 750 °C) than that of the low temperature grown sample (1.1 × 10{sup 9} cm{sup −2} at 730 °C). A correlation between growth temperature and concentration of deep centre defect states from photoluminescence spectra is also presented. The GaN film grown at 750 °C exhibits the lowest defect concentration which confirms that the growth temperature strongly influences the surface morphology and affects the optical properties of the GaN epitaxial films.

  4. Measuring the Ablative Richtmyer-Meshkov Growth of Isolated Defects on Plastic Capsules

    NASA Astrophysics Data System (ADS)

    Loomis, Eric; Braun, Dave; Batha, Steve; Sedillo, Tom; Evans, Scott; Sorce, Chuck; Landen, Otto

    2010-11-01

    To achieve thermonuclear ignition at Megajoule class laser systems such as the NIF using inertially confined plasmas, targets must be designed with high in-flight aspect ratios (IFAR) resulting in low shell stability. Recent simulations and experiments have shown that isolated features on the outer surface of an ignition capsule can profoundly impact capsule performance by leading to material jetting or mix into the hotspot. Unfortunately, our ability to accurately predict these effects is uncertain due to disagreement between equation of state (EOS) models. In light of this, we have begun a campaign to measure the growth of isolated defects due to ablative Richtmyer-Meshkov in CH capsules to validate these models. Face- on transmission radiography has been used to measure the evolution of Gaussian bump arrays in plastic targets. Targets were indirectly-driven using Au halfraums to radiation temperatures near 65-75 eV at the Omega laser (Laboratory for Laser Energetics, University of Rochester, NY) simultaneous with x-ray backlighting from a saran (Cl) foil. Shock speed measurements were also made to determine drive conditions in the target. The results from these experiments will aid in the design of ignition drive pulses that minimize bump amplitude at the time of shell acceleration.

  5. ADAM12-deficient zebrafish exhibit retardation in body growth at the juvenile stage without developmental defects.

    PubMed

    Tokumasu, Yudai; Iida, Atsuo; Wang, Zi; Ansai, Satoshi; Kinoshita, Masato; Sehara-Fujisawa, Atsuko

    2016-05-01

    ADAM (a disintegrin and metalloprotease) constitutes a family of multi-domain proteins that are involved in development, homeostasis, and disease. ADAM12 plays important roles in myogenesis and adipogenesis in mice; however, the precise physiological mechanisms are not known, and the function of this gene in other vertebrates has not been examined. In this study, we used a simple model vertebrate, the zebrafish, to investigate the functions of ADAM12 during development. Zebrafish adam12 is conserved with those of mammals in the synteny and the amino-acid sequence. We examined adam12 expression in zebrafish embryos by whole mount in situ hybridization and the promoter activity of the adam12 upstream sequence. We found that adam12 is strongly expressed in the cardiovascular system, erythroid progenitors, brain, and jaw cartilage during zebrafish development, and adam12-knockout zebrafish exhibited reduced body size in the juvenile stage without apparent morphological defects. Taken together, these results suggest that adam12 plays a significant role in the regulation of body growth during juvenile stage in zebrafish, although the precise molecular mechanisms await further study. PMID:27185351

  6. Novel Therapy to Treat Corneal Epithelial Defects: A Hypothesis with Growth Hormone.

    PubMed

    Wirostko, Barbara; Rafii, MaryJane; Sullivan, David A; Morelli, Julia; Ding, Juan

    2015-07-01

    Impaired corneal wound healing that occurs with ocular surface disease, trauma, systemic disease, or surgical intervention can lead to persistent corneal epithelial defects (PCED), which result in corneal scarring, ulceration, opacification, corneal neovascularization, and, ultimately, visual compromise and vision loss. The current standard of care can include lubricants, ointments, bandage lenses, amniotic membranes, autologous serum eye drops, and corneal transplants. Various inherent problems exist with application and administration of these treatments, which often may not result in a completely healed surface. A topically applicable compound capable of promoting corneal epithelial cell proliferation and/or migration would be ideal to accelerate healing. We hypothesize that human growth hormone (HGH) is such a compound. In a recent study, HGH was shown to activate signal transducer and activators of transcription-5 (STAT5) signaling and promote corneal wound healing by enhancing corneal epithelial migration in a co-culture system of corneal epithelial cells and fibroblasts. These effects require an intact communication between corneal epithelia and fibroblasts. Further, HGH promotes corneal wound healing in a rabbit debridement model, thus demonstrating the effectiveness of HGH in vivo as well. In conclusion, HGH may represent an exciting and effective topical therapeutic to promote corneal wound healing. PMID:26045234

  7. Erratic Dislocations within Funnel Defects in AlN Templates for AlGaNEpitaxial Layer Growth

    SciTech Connect

    Hawkridge, Michael E; Liliental-Weber, Zuzanna; Jin Kim, Hee; Choi, Suk; Yoo, Dongwon; Ryou, Jae-Hyun; Dupuis, Russel D

    2009-03-13

    We report our transmission electron microscopy observations of erraticdislocation behavior within funnel-like defects in the top of AlN templates filled withAlGaN from an overlying epitaxial layer. This dislocation behavior is observed inmaterial where phase separation is also observed. Several bare AlN templates wereexamined to determine the formation mechanism of the funnels. Our results suggest that they are formed prior to epitaxial layer deposition due to the presence of impuritiesduring template re-growth. We discuss the erratic dislocation behavior in relation to thepresence of the phase-separated material and the possible effects of these defects on the optoelectronic properties.

  8. Endochondral Growth Defect and Deployment of Transient Chondrocyte Behaviors Underlie Osteoarthritis Onset in a Natural Murine Model

    PubMed Central

    Staines, K. A.; Madi, K.; Mirczuk, S. M.; Parker, S.; Burleigh, A.; Poulet, B.; Hopkinson, M.; Bodey, A. J.; Fowkes, R. C.; Farquharson, C.; Lee, P. D.

    2016-01-01

    Objective To explore whether aberrant transient chondrocyte behaviors occur in the joints of STR/Ort mice (which spontaneously develop osteoarthritis [OA]) and whether they are attributable to an endochondral growth defect. Methods Knee joints from STR/Ort mice with advanced OA and age‐matched CBA (control) mice were examined by Affymetrix microarray profiling, multiplex polymerase chain reaction (PCR) analysis, and immunohistochemical labeling of endochondral markers, including sclerostin and MEPE. The endochondral phenotype of STR/Ort mice was analyzed by histologic examination, micro–computed tomography, and ex vivo organ culture. A novel protocol for quantifying bony bridges across the murine epiphysis (growth plate fusion) using synchrotron x‐ray computed microtomography was developed and applied. Results Meta‐analysis of transcription profiles showed significant elevation in functions linked with endochondral ossification in STR/Ort mice (compared to CBA mice; P < 0.05). Consistent with this, immunolabeling revealed increased matrix metalloproteinase 13 (MMP‐13) and type X collagen expression in STR/Ort mouse joints, and multiplex quantitative reverse transcriptase–PCR showed differential expression of known mineralization regulators, suggesting an inherent chondrocyte defect. Support for the notion of an endochondral defect included accelerated growth, increased zone of growth plate proliferative chondrocytes (P < 0.05), and widespread type X collagen/MMP‐13 labeling beyond the expected hypertrophic zone distribution. OA development involved concomitant focal suppression of sclerostin/MEPE in STR/Ort mice. Our novel synchrotron radiation microtomography method showed increased numbers (P < 0.001) and mean areal growth plate bridge densities (P < 0.01) in young and aged STR/Ort mice compared to age‐matched CBA mice. Conclusion Taken together, our data support the notion of an inherent endochondral defect that is linked to growth dynamics and

  9. Adenoma-linked barrier defects and microbial products drive IL-23/IL-17-mediated tumour growth

    PubMed Central

    Grivennikov, Sergei I.; Wang, Kepeng; Mucida, Daniel; Stewart, C. Andrew; Schnabl, Bernd; Jauch, Dominik; Taniguchi, Koji; Yu, Guann-Yi; Osterreicher, Christoph H.; Hung, Kenneth E.; Datz, Christian; Feng, Ying; Fearon, Eric R.; Oukka, Mohamed; Tessarollo, Lino; Coppola, Vincenzo; Yarovinsky, Felix; Cheroutre, Hilde; Eckmann, Lars; Trinchieri, Giorgio; Karin, Michael

    2013-01-01

    Approximately 2% of colorectal cancer is linked to pre-existing inflammation known as colitis-associated cancer, but most develops in patients without underlying inflammatory bowel disease. Colorectal cancer often follows a genetic pathway whereby loss of the adenomatous polyposis coli (APC) tumour suppressor and activation of β-catenin are followed by mutations in K-Ras, PIK3CA and TP53, as the tumour emerges and progresses1,2. Curiously, however, ‘inflammatory signature’ genes characteristic of colitis-associated cancer are also upregulated in colorectal cancer3,4. Further, like most solid tumours, colorectal cancer exhibits immune/inflammatory infiltrates5, referred to as ‘tumour elicited inflammation’6. Although infiltrating CD4+ TH1 cells and CD8+ cytotoxic T cells constitute a positive prognostic sign in colorectal cancer7,8, myeloid cells and T-helper interleukin (IL)-17-producing (TH17) cells promote tumorigenesis5,6, and a ‘TH17 expression signature’ in stage I/II colorectal cancer is associated with a drastic decrease in disease-free survival9. Despite its pathogenic importance, the mechanisms responsible for the appearance of tumour-elicited inflammation are poorly understood. Many epithelial cancers develop proximally to microbial communities, which are physically separated from immune cells by an epithelial barrier10. We investigated mechanisms responsible for tumour-elicited inflammation in a mouse model of colorectal tumorigenesis, which, like human colorectal cancer, exhibits upregulation of IL-23 and IL-17. Here we show that IL-23 signalling promotes tumour growth and progression, and development of a tumoural IL-17 response. IL-23 is mainly produced by tumour-associated myeloid cells that are likely to be activated by microbial products, which penetrate the tumours but not adjacent tissue. Both early and late colorectal neoplasms exhibit defective expression of several barrier proteins. We propose that barrier deterioration induced by

  10. [NiFe]-hydrogenase is essential for cyanobacterium Synechocystis sp. PCC 6803 aerobic growth in the dark

    PubMed Central

    De Rosa, Edith; Checchetto, Vanessa; Franchin, Cinzia; Bergantino, Elisabetta; Berto, Paola; Szabò, Ildikò; Giacometti, Giorgio M.; Arrigoni, Giorgio; Costantini, Paola

    2015-01-01

    The cyanobacterium Synechocystis sp. PCC 6803 has a bidirectional [NiFe]-hydrogenase (Hox hydrogenase) which reversibly reduces protons to H2. This enzyme is composed of a hydrogenase domain and a diaphorase moiety, which is distinctly homologous to the NADH input module of mitochondrial respiratory Complex I. Hox hydrogenase physiological function is still unclear, since it is not required for Synechocystis fitness under standard growth conditions. We analyzed the phenotype under prolonged darkness of three Synechocystis knock-out strains, lacking either Hox hydrogenase (ΔHoxE-H) or one of the proteins responsible for the assembly of its NiFe active site (ΔHypA1 and ΔHypB1). We found that Hox hydrogenase is required for Synechocystis growth under this condition, regardless of the functional status of its catalytic site, suggesting an additional role beside hydrogen metabolism. Moreover, quantitative proteomic analyses revealed that the expression levels of several subunits of the respiratory NADPH/plastoquinone oxidoreductase (NDH-1) are reduced when Synechocystis is grown in the dark. Our findings suggest that the Hox hydrogenase could contribute to electron transport regulation when both photosynthetic and respiratory pathways are down-regulated, and provide a possible explanation for the close evolutionary relationship between mitochondrial respiratory Complex I and cyanobacterial [NiFe]-hydrogenases. PMID:26215212

  11. WASP suppresses the growth defect of Saccharomyces cerevisiae las17Delta strain in the presence of WIP.

    PubMed

    Rajmohan, Rajamuthiah; Meng, Lei; Yu, Shangjuan; Thanabalu, Thirumaran

    2006-04-01

    Wiskott-Aldrich syndrome is caused by alterations in the Wiskott-Aldrich syndrome protein (WASP) and several of these mutations affect WASP's interaction with WIP (WASP-interacting protein), suggesting that loss of interaction between WASP and WIP is causal to the disease. Las17p is the yeast homologue of WASP and las17Delta strain is unable to grow at 37 degrees C. We show that Human WASP suppresses the growth defect of Saccharomyces cerevisiae las17Delta strain, only in the presence of WIP. WIP mediates cortical localisation of WASP as well as stabilise WASP in yeast cells. Mutations which affected WASP-WIP interaction abolished WASP's ability to suppress the growth defect of las17Delta strain. We have demonstrated that WASP-WIP is an active complex and WASP's ability to suppress the growth defect of las17Delta strain is dependent on the presence of a functional Arp2/3 activating domain of WASP and also the Verprolin domain (V) of WIP. PMID:16488394

  12. Posttranscriptional Control of T Cell Effector Function by Aerobic Glycolysis

    PubMed Central

    Chang, Chih-Hao; Curtis, Jonathan D.; Maggi, Leonard B.; Faubert, Brandon; Villarino, Alejandro V.; O’Sullivan, David; Huang, Stanley Ching-Cheng; van der Windt, Gerritje J.W.; Blagih, Julianna; Qiu, Jing; Weber, Jason D.; Pearce, Edward J.; Jones, Russell G.; Pearce, Erika L.

    2013-01-01

    SUMMARY A “switch” from oxidative phosphorylation (OXPHOS) to aerobic glycolysis is a hallmark of T cell activation and is thought to be required to meet the metabolic demands of proliferation. However, why proliferating cells adopt this less efficient metabolism, especially in an oxygen-replete environment, remains incompletely understood. We show here that aerobic glycolysis is specifically required for effector function in T cells but that this pathway is not necessary for proliferation or survival. When activated T cells are provided with costimulation and growth factors but are blocked from engaging glycolysis, their ability to produce IFN-γ is markedly compromised. This defect is translational and is regulated by the binding of the glycolysis enzyme GAPDH to AU-rich elements within the 3′ UTR of IFN-γ mRNA. GAPDH, by engaging/disengaging glycolysis and through fluctuations in its expression, controls effector cytokine production. Thus, aerobic glycolysis is a metabolically regulated signaling mechanism needed to control cellular function. PMID:23746840

  13. Lymphocyte dysfunction in cartilage hair hypoplasia. II. Evidence for a cell cycle specific defect in T cell growth

    PubMed Central

    Pierce, G. F.; Polmar, S. H.

    1982-01-01

    Defects of in vitro B and T lymphocyte function and impaired delayed type hypersen-sitivity reactions, as well as an increased risk of lethal viral infections have been reported in cartilage hair hypoplasia (CHH), an autosomal recessive form of short limbed dwarfism. We have previously found an intrinsic proliferative defect that affected several cell types from CHH individuals. In order to further evaluate it we developed continuous T cell lines (CTCL) from CHH and normal individuals. The T cells from cultures of CHH and normal individuals were indistinguishable with respect to cell surface antigens characteristic of fully differentiated T cells, as defined by monoclonal antibody analysis. However, CHH T cells produced significantly less interleukin 2 (IL2) than normal T cells and the growth of CHH CTCL in response to exogenously supplied IL2 was markedly diminished (cell cycle 120-165 hr) compared to normal CTCL (cell cycle 48-60 hr). Furthermore, the exogenous IL2 was not absorbed from growth medium by CHH CTCL at the same rate as normal CTCL. Both production and utilization of IL2 are cell cycle specific events that occur during G1 phase before the onset of DNA synthesis (S phase). Thus, CHH T lymphocytes appear to have a defect related to G1 phase that results in a longer cell cycle for individual cells, and leads to decreased proliferation of the population. We postulate that this G1 phase defect is present in multiple cell types in CHH and that analysis of continuous T cell lines from CHH individuals may permit the identification of this defect. PMID:6984669

  14. Influence of growth temperature and temperature ramps on deep level defect incorporation in m-plane GaN

    SciTech Connect

    Armstrong, A. M.; Kelchner, K.; Nakamura, S.; DenBaars, S. P.; Speck, J. S.

    2013-12-02

    The dependence of deep level defect incorporation in m-plane GaN films grown by metal-organic chemical vapor deposition on bulk m-plane GaN substrates as a function of growth temperature (T{sub g}) and T{sub g} ramping method was investigated using deep level optical spectroscopy. Understanding the influence of T{sub g} on GaN deep level incorporation is important for InGaN/GaN multi-quantum well (MQW) light emitting diodes (LEDs) and laser diodes (LDs) because GaN quantum barrier (QB) layers are grown much colder than thin film GaN to accommodate InGaN QW growth. Deep level spectra of low T{sub g} (800 °C) GaN films grown under QB conditions were compared to deep level spectra of high T{sub g} (1150 °C) GaN. Reducing T{sub g}, increased the defect density significantly (>50×) through introduction of emergent deep level defects at 2.09 eV and 2.9 eV below the conduction band minimum. However, optimizing growth conditions during the temperature ramp when transitioning from high to low T{sub g} substantially reduced the density of these emergent deep levels by approximately 40%. The results suggest that it is important to consider the potential for non-radiative recombination in QBs of LED or LD active regions, and tailoring the transition from high T{sub g} GaN growth to active layer growth can mitigate such non-radiative channels.

  15. Simulating Interface Growth and Defect Generation in CZT – Simulation State of the Art and Known Gaps

    SciTech Connect

    Henager, Charles H.; Gao, Fei; Hu, Shenyang Y.; Lin, Guang; Bylaska, Eric J.; Zabaras, Nicholas

    2012-11-01

    This one-year, study topic project will survey and investigate the known state-of-the-art of modeling and simulation methods suitable for performing fine-scale, fully 3-D modeling, of the growth of CZT crystals at the melt-solid interface, and correlating physical growth and post-growth conditions with generation and incorporation of defects into the solid CZT crystal. In the course of this study, this project will also identify the critical gaps in our knowledge of modeling and simulation techniques in terms of what would be needed to be developed in order to perform accurate physical simulations of defect generation in melt-grown CZT. The transformational nature of this study will be, for the first time, an investigation of modeling and simulation methods for describing microstructural evolution during crystal growth and the identification of the critical gaps in our knowledge of such methods, which is recognized as having tremendous scientific impacts for future model developments in a wide variety of materials science areas.

  16. Influence of substrate surface defects on the homoepitaxial growth of GaN (0001) by metalorganic vapor phase epitaxy

    NASA Astrophysics Data System (ADS)

    Zhou, Kun; Liu, Jianping; Ikeda, Masao; Zhang, Shuming; Li, Deyao; Zhang, Liqun; Zeng, Chang; Yang, Hui

    2015-04-01

    Surface morphology of homoepitaxial GaN (0001) grown by metalorganic vapor phase epitaxy was studied. Selective growth was observed on the homoepitaxial GaN layer grown on as-received GaN substrate and was attributed to the existence of substrate surface defects. The steps were pinned by defects and meandered. Due to the pinning effect, the step pattern developed to a wavy surface with a strip-like feature along the [ 11 2 bar 0] direction during the subsequent growth of a thick n-GaN layer. Because of the surface undulations, the emission of InGaN/GaN multiple quantum wells grown on the n-GaN layer was inhomogeneous. The surface defects on GaN substrate could be removed by dry etching and the homoepitaxial layer on the etched substrate showed a smooth morphology and straight atomic steps. As a result, the emission of the InGaN/GaN MQWs became homogeneous.

  17. Repair of osteochondral defects with adipose stem cells and a dual growth factor-releasing scaffold in rabbits.

    PubMed

    Im, Gun-Il; Lee, Jin Ho

    2010-02-01

    The purpose of this work was to evaluate the in vivo effectiveness of a TGF-beta(2) and bone morphogenetic protein (BMP)-7-immobilized porous polycaprolactone (PCL)/F127 scaffold to enhance the healing of cartilage defect. An osteochondral defect was created on the patellar groove of the right distal femur of 12 rabbits and managed by one of the following methods: filling it with the scaffold only (Group I); the scaffold seeded with adipose stem cells (ASCs) (Group II); a TGF-beta(2) and BMP-7-immobilized scaffold (Group III); and a TGF-beta(2) and BMP-7-immobilized scaffold seeded with ASCs (Group IV). Each group had three rabbits. Nine weeks after the implantation, the implanted scaffolds were filled with yellowish, dense tissue, and had distinct margins with adjacent normal cartilage. The histological findings showed infiltration of foreign-body giant cells and blood vessel, more prominently in Groups III and IV. The presence of growth factor significantly increased the ICRS Macroscopic Score (p = 0.045) while the presence of ASC did not. The ICRS Visual Histological Score was not significantly affected by the presence of either growth factors or ASCs, showing similar values in all groups. In conclusion, the use of TGF-beta(2) and BMP-7-immobilized PCL/F127 scaffolds improved gross appearances of the osteochondral defects while not actually leading to better histological results and induced a greater degree of foreign body reaction. PMID:19957354

  18. Effects of local defect growth in direct-drive cryogenic implosions on OMEGA

    SciTech Connect

    Igumenshchev, I. V.; Shmayda, W. T.; Harding, D. R.; Sangster, T. C.; Goncharov, V. N.; Meyerhofer, D. D.

    2013-08-15

    Spherically symmetric, low-adiabat (adiabat α ≲ 3) cryogenic direct-drive-implosion experiments on the OMEGA laser [T. R. Boehly et al., Opt. Commun. 133, 495 (1995)] yield less than 10% of the neutrons predicted in one-dimensional hydrodynamic simulations. Two-dimensional hydrodynamic simulations suggest that this performance degradation can be explained assuming perturbations from isolated defects of submicron to tens-of-micron scale on the outer surface or inside the shell of implosion targets. These defects develop during the cryogenic filling process and typically number from several tens up to hundreds for each target covering from about 0.2% to 1% of its surface. The simulations predict that such defects can significantly perturb the implosion and result in the injection of about 1 to 2 μg of the hot ablator (carbon-deuterium) and fuel (deuterium-tritium) materials from the ablation surface into the targets. Both the hot mass injection and perturbations of the shell reduce the final shell convergence ratio and implosion performance. The injected carbon ions radiatively cool the hot spot, reducing the fuel temperature, and further reducing the neutron yield. The negative effect of local defects can be minimized by decreasing the number and size of these defects and/or using more hydrodynamically stable implosion designs with higher shell adiabat.

  19. Teaching Aerobic Fitness Concepts.

    ERIC Educational Resources Information Center

    Sander, Allan N.; Ratliffe, Tom

    2002-01-01

    Discusses how to teach aerobic fitness concepts to elementary students. Some of the K-2 activities include location, size, and purpose of the heart and lungs; the exercise pulse; respiration rate; and activities to measure aerobic endurance. Some of the 3-6 activities include: definition of aerobic endurance; heart disease risk factors;…

  20. Growth defects in the dorsal pallium after genetically targeted ablation of principal preplate neurons and neuroblasts: a morphometric analysis

    PubMed Central

    Fisher, Robin; Xie, Yuan-Yun

    2010-01-01

    The present study delineates the large-scale, organic responses of growth in the dorsal pallium to targeted genetic ablations of the principal PP (preplate) neurons of the neocortex. Ganciclovir treatment during prenatal development [from E11 (embryonic age 11) to E13] of mice selectively killed cells with shared S-phase vulnerability and targeted expression of a GPT [golli promoter transgene; GPT linked to HSV-TK (herpes simplex virus-thymidine kinase), τ-eGFP and lacZ reporters] localized in PP neurons and their intermediate progenitor neuroblasts. The volume, area and thickness of the pallium were measured in an E12–P4 (postnatal age 4) longitudinal study with comparisons between ablated (HSV-TK+/0) and control (HSV-TK0/0) littermates. The extent of ablations was also systematically varied, and the effect on physical growth was assessed in an E18 cross-sectional study. The morphological evidence obtained in the present study supports the conclusion that genetically targeted ablations delay the settlement of the principal PP neurons of the dorsal pallium. This leads to progressive and substantial reductions of growth, despite compensatory responses that rapidly replace the ablated cells. These growth defects originate from inductive cellular interactions in the proliferative matrix of the ventricular zone of the pallium, but are amplified by subsequent morphogenic and trophic cellular interactions. The defects persist during the course of prenatal and postnatal development to demonstrate a constrained dose–response relationship with the extent of specific killing of GPT neurons. The defects propagate simultaneously in both the horizontal and vertical cytoarchitectural dimensions of the developing pallium, an outcome that produces a localized shortfall of volume in the telencephalic vesicles. PMID:20957077

  1. Identification and Control of Gravity Related Defect Formation During Melt Growth of Electro-Optic Single Crystals Bismuth Silicate(Bi12SiO20)

    NASA Technical Reports Server (NTRS)

    Becia, Piotr; Wiegel, Michaela E. K.

    2004-01-01

    A research carried out under Award Number NAG8-1487 was aimed at to the design, conduct and analysis of experiments directed at the identification and control of gravitational effects on crystal growth, segregation and defect formation in the Sillenite system: bismuth silicate (Bi(12)SiO(20)). Correlation analyses was conducted in order to establish the influence of gravity related defects introduced during crystal growth on critical, application specific properties. Achievement of the states objective was conducted during the period from Feb. 01, 1998 to Dec. 31, 2003 with the following anticipated milestones: 1. Establishment of capabilities for (a) reproducible Czochralski and Bridgman-type growth of BSO single crystals and (b) for comprehensive analysis of crystalline and chemical defects as well as for selective property characterization of grown crystals (year 1). 2. Design and execution of critical space growth experiment(s) based on analyses of prefatory space results (experiments aimed at establishing the viability of planned approaches and procedures) and on unresolved issues related to growth, segregation and defect formation associated with conventional growth in Bridgman geometries. Comparative analysis of growth under conventional and under mu-g conditions; identification of gravity related defect formation during conventional Bridgman growth and formulation of approaches for their control (years 2 and 3). Development of charge confinement system which permits growth interface demarcation (in a mu-g environment) as well as minimization of confinement related stress and contamination during growth; design of complementary mu-g growth experiments aimed at quantitative mu-g growth and segregation analyses (year 4). 3. Conduct of quantitative mu-g growth experiments directed at: (a) identification and control of gravity related crystalline and chemical defect formation during single crystal growth of Bi(12)SiO(20) and at (b) defect engineering -the

  2. Expression of Moloney Murine Leukemia Virus RNase H Rescues the Growth Defect of an Escherichia coli Mutant

    PubMed Central

    Campbell, Andrew G.

    2001-01-01

    A 157-amino-acid fragment of Moloney murine leukemia virus reverse transcriptase encoding RNase H is shown to rescue the growth-defective phenotype of an Escherichia coli mutant. In vitro assays of the recombinant wild-type protein purified from the conditionally defective mutant confirm that it is catalytically active. Mutagenesis of one of the presumptive RNase H-catalytic residues results in production of a protein variant incapable of rescue and which lacks activity in vitro. Analyses of additional active site mutants demonstrate that their encoded variant proteins lack robust activity yet are able to rescue the bacterial mutant. These results suggest that genetic complementation may be useful for in vivo screening of mutant viral RNase H gene fragments and in evaluating their function under conditions that more closely mimic physiological conditions. The rescue system may also be useful in verifying the functional outcomes of mutations based on protein structural predictions and modeling. PMID:11390625

  3. Cellular growth defects triggered by an overload of protein localization processes

    PubMed Central

    Kintaka, Reiko; Makanae, Koji; Moriya, Hisao

    2016-01-01

    High-level expression of a protein localized to an intracellular compartment is expected to cause cellular defects because it overloads localization processes. However, overloads of localization processes have never been studied systematically. Here, we show that the expression levels of green fluorescent proteins (GFPs) with localization signals were limited to the same degree as a toxic misfolded GFP in budding yeast cells, and that their high-level expression caused cellular defects associated with localization processes. We further show that limitation of the exportin Crm1 determined the expression limit of GFP with a nuclear export signal. Although misfolding of GFP with a vesicle-mediated transport signal triggered endoplasmic reticulum stress, it was not the primary determinant of its expression limit. The precursor of GFP with a mitochondrial targeting signal caused a cellular defect. Finally, we estimated the residual capacities of localization processes. High-level expression of a localized protein thus causes cellular defects by overloading the capacities of localization processes. PMID:27538565

  4. Cellular growth defects triggered by an overload of protein localization processes.

    PubMed

    Kintaka, Reiko; Makanae, Koji; Moriya, Hisao

    2016-01-01

    High-level expression of a protein localized to an intracellular compartment is expected to cause cellular defects because it overloads localization processes. However, overloads of localization processes have never been studied systematically. Here, we show that the expression levels of green fluorescent proteins (GFPs) with localization signals were limited to the same degree as a toxic misfolded GFP in budding yeast cells, and that their high-level expression caused cellular defects associated with localization processes. We further show that limitation of the exportin Crm1 determined the expression limit of GFP with a nuclear export signal. Although misfolding of GFP with a vesicle-mediated transport signal triggered endoplasmic reticulum stress, it was not the primary determinant of its expression limit. The precursor of GFP with a mitochondrial targeting signal caused a cellular defect. Finally, we estimated the residual capacities of localization processes. High-level expression of a localized protein thus causes cellular defects by overloading the capacities of localization processes. PMID:27538565

  5. A comparison of the distribution of extracellular proteins produced by the protease-secreting organism Aeromonas salmonicida during aerobic and anaerobic growth.

    PubMed

    Fyfe, L; Coleman, G; Munro, A L

    1986-01-01

    Aeromonas salmonicida was grown aerobically and anaerobically in supplemented 3% (w/v) tryptone soya broth medium for 24 h at 25 degrees C. Although the bacterial density achieved was 4.9 times higher in the aerobic culture, the exoprotein produced per unit of bacterial dry weight was only 1.9 times higher than in the anaerobic culture. However, the protease activity of the exoprotein showed a marked reduction anaerobically, being only one-tenth of that of the exoprotein produced aerobically. This finding was consistent with the differing SDS-PAGE patterns of the extracellular proteins from the two cultures, which also showed marked loss and reinforcement of other, as yet unidentified extracellular products. PMID:3322167

  6. Theoretical study of defect formation during the initial stages of native-oxide growth on GaSb (001)

    SciTech Connect

    Bermudez, V. M.

    2014-04-07

    The formation of defects during the initial stages of native-oxide growth on the GaSb (001)-α(4 × 3) surface has been studied computationally using spin-unrestricted density functional theory. It is found that insertion into a Ga-Sb adatom dimer to form a peroxo Ga-O-O-Sb bridge is the most energetically favorable process with insertion into Ga-Sb back-bonds being somewhat less so. A Ga-O-O-Ga bridge between dimers is also favorable, but Sb-O-O-Sb bridges show little if any stability. In the course of analyzing molecular adsorption, a particularly reactive site has been identified that leads to O{sub 2} dissociation with little or no barrier. This process is initiated in the vicinity of an Sb-Sb dimer in the terminating layer and leads to sub-surface Ga and Sb defect sites (i.e., coordinatively unsaturated atoms) and to strained Ga-Sb bonds that may be susceptible to further O{sub 2} attack. However, the defects formed in these reactions do not produce states in the gap.

  7. Defect, Kinetics and Heat Transfer of CDTE Bridgman Growth without Wall Contact

    NASA Technical Reports Server (NTRS)

    Larson, D. J., Jr.; Zhang, H.

    2003-01-01

    A detached growth mechanism has been proposed, which is similar to that proposed by Duffar et al. and used to study the current detached growth system. From numerical results, we can conclude that detached growth will more likely appear if the growth and wetting angles are large and meniscus is flat. Detached thickness is dependent on growth angle, wetting angle, and gap width and shape of the fins. The model can also explain why the detached growth will not happen for metals in which the growth angle is almost zero. Since the growth angle of CdZnTe cannot be changed, to promote detached growth, the number density of the fins should be low and the wetting angle should be high. Also, a much smaller gap width of the fins should be used in the ground experiment and the detached gap width is much smaller. The shape of the fins has minor influence on detached growth. An integrated numerical model for detached solidification has been developed combining a global heat transfer sub-model and a wall contact sub-model. The global heat transfer sub-model accounts for heat and mass transfer in the multiphase system, convection in the melt, macro-segregation, and interface dynamics. The location and dynamics of the solidification interface are accurately tracked by a multizone adaptive grid generation scheme. The wall contact sub-model accounts for the meniscus dynamics at the three-phase boundary. Simulations have been performed for crystal growth in a conventional ampoule and a designed ampoule to understand the benefits of detached solidification and its impacts on crystalline structural quality, e.g., stoichiometry, macro-segregation, and stress. From simulation results, both the Grashof and Marangoni numbers will have significant effects on the shape of growth front, Zn concentration distribution, and radial segregation. The integrated model can be used in designing apparatus and determining the optimal geometry for detached solidification in space and on the ground.

  8. Effects of hydraulic retention time on aerobic granulation and granule growth kinetics at steady state with a fast start-up strategy.

    PubMed

    Liu, Yong-Qiang; Zhang, Xing; Zhang, Rui; Liu, Wen-Tso; Tay, Joo-Hwa

    2016-01-01

    A hydraulic retention time (HRT) of 4, 6, and 8 h was employed, respectively, in three reactors to study the effects of HRT on granulation with a newly developed fast granulation strategy, i.e., a strategy by combining strong hydraulic selection pressure with high organic loading rate (OLR). Granules with clear boundary appeared within 24 h after reactor start-up and all reactors reached a pseudo steady state after 6-day operation. A 4-h HRT resulted in a relatively higher increasing rate in terms of granule size during granule development period, i.e., 208 μm day(-1), and the bigger granule size and the higher sludge volume index at the pseudo steady state. For HRT of 6 or 8 h, no obvious difference was observed. However, it was found that HRT influenced sludge retention time (SRT) and kinetics significantly. A HRT changing from 4 to 8 h led to an increased SRT from 3 to 21 days, a decreased observed specific biomass growth rate (μ obs) and an decreased observed biomass yield (Y obs) of stable granules from 0.37 to 0.062 days(-1), and 0.177 to 0.055 g MLVSS g(-1) COD, respectively. Both μ obs and Y obs had a linear relationship with the reciprocal of HRT. In addition, the great difference of microbial community between seed sludge, sludge retained in the reactors, and sludge washed out indicated a strong microbial selection for fast granulation within 24 h. However, during the granule development period from day 1 to 6, no more microbial selection was observed except an adjustment of microbial community. Little influence of HRT on microbial population in granular sludge indicated a minor role of HRT played for granulation with the fast start-up strategy adopted in this study. The results demonstrated that hydraulic selection pressure for granulation was mainly from short settling time, which led to strong microbial selection during the granulation period. Meanwhile, although HRT did not affect granulation with the fast start-up strategy, it played an

  9. Signaling through the Phosphatidylinositol 3-Kinase (PI3K)/Mammalian Target of Rapamycin (mTOR) Axis Is Responsible for Aerobic Glycolysis mediated by Glucose Transporter in Epidermal Growth Factor Receptor (EGFR)-mutated Lung Adenocarcinoma*

    PubMed Central

    Makinoshima, Hideki; Takita, Masahiro; Saruwatari, Koichi; Umemura, Shigeki; Obata, Yuuki; Ishii, Genichiro; Matsumoto, Shingo; Sugiyama, Eri; Ochiai, Atsushi; Abe, Ryo; Goto, Koichi; Esumi, Hiroyasu; Tsuchihara, Katsuya

    2015-01-01

    Oncogenic epidermal growth factor receptor (EGFR) signaling plays an important role in regulating global metabolic pathways, including aerobic glycolysis, the pentose phosphate pathway (PPP), and pyrimidine biosynthesis. However, the molecular mechanism by which EGFR signaling regulates cancer cell metabolism is still unclear. To elucidate how EGFR signaling is linked to metabolic activity, we investigated the involvement of the RAS/MEK/ERK and PI3K/AKT/mammalian target of rapamycin (mTOR) pathways on metabolic alteration in lung adenocarcinoma (LAD) cell lines with activating EGFR mutations. Although MEK inhibition did not alter lactate production and the extracellular acidification rate, PI3K/mTOR inhibitors significantly suppressed glycolysis in EGFR-mutant LAD cells. Moreover, a comprehensive metabolomics analysis revealed that the levels of glucose 6-phosphate and 6-phosphogluconate as early metabolites in glycolysis and PPP were decreased after inhibition of the PI3K/AKT/mTOR pathway, suggesting a link between PI3K signaling and the proper function of glucose transporters or hexokinases in glycolysis. Indeed, PI3K/mTOR inhibition effectively suppressed membrane localization of facilitative glucose transporter 1 (GLUT1), which, instead, accumulated in the cytoplasm. Finally, aerobic glycolysis and cell proliferation were down-regulated when GLUT1 gene expression was suppressed by RNAi. Taken together, these results suggest that PI3K/AKT/mTOR signaling is indispensable for the regulation of aerobic glycolysis in EGFR-mutated LAD cells. PMID:26023239

  10. Pharmacologic rescue of axon growth defects in a human iPSC model of hereditary spastic paraplegia SPG3A.

    PubMed

    Zhu, Peng-Peng; Denton, Kyle R; Pierson, Tyler Mark; Li, Xue-Jun; Blackstone, Craig

    2014-11-01

    Hereditary spastic paraplegias are a large, diverse group of neurological disorders (SPG1-71) with the unifying feature of prominent lower extremity spasticity, owing to a length-dependent axonopathy of corticospinal motor neurons. The most common early-onset form of pure, autosomal dominant hereditary spastic paraplegia is caused by mutation in the ATL1 gene encoding the atlastin-1 GTPase, which mediates homotypic fusion of ER tubules to form the polygonal ER network. We have identified a p.Pro342Ser mutation in a young girl with pure SPG3A. This residue is in a critical hinge region of atlastin-1 between its GTPase and assembly domains, and it is conserved in all known eukaryotic atlastin orthologs. We produced induced pluripotent stem cells from skin fibroblasts and differentiated these into forebrain neurons to generate a human neuronal model for SPG3A. Axons of these SPG3A neurons showed impaired growth, recapitulating axonal defects in atlastin-1-depleted rat cortical neurons and impaired root hair growth in loss-of-function mutants of the ATL1 ortholog rhd3 in the plant Arabidopsis. Both the microtubule cytoskeleton and tubular ER are important for mitochondrial distribution and function within cells, and SPG3A neurons showed alterations in mitochondrial motility. Even so, it is not clear whether this change is involved in disease pathogenesis. The SPG3A axon growth defects could be rescued with microtubule-binding agents, emphasizing the importance of tubular ER interactions with the microtubule cytoskeleton in hereditary spastic paraplegia pathogenesis. The prominent alterations in axon growth in SPG3A neurons may represent a particularly attractive target for suppression in screens for novel pharmacologic agents. PMID:24908668

  11. Control of the growth of Microthrix parvicelle by using an aerobic selector--results of pilot and full scale plant operation.

    PubMed

    Lebek, M; Rosenwinkel, K H

    2002-01-01

    A two-stage wastewater treatment plant experiences bulking sludge problems in winter, correlating with Microthixparvicella abundance. Pilot and full-scale studies of the use of an aerobic selector to control M. parvicella had little success, probably resulting from long chain fatty acid retention in foam at the tank surface. Initial pilot studies with reduced foam retention showed better results. PMID:12216674

  12. Transforming growth factor-beta reverses a posttranscriptional defect in elastin synthesis in a cutis laxa skin fibroblast strain.

    PubMed Central

    Zhang, M C; Giro, M; Quaglino, D; Davidson, J M

    1995-01-01

    Skin fibroblasts from two cases of autosomal recessive cutis laxa (CL), having insignificant elastin production and mRNA levels, were challenged with transforming growth factor beta-1 (TGF-beta 1). Elastin production was brought from undetectable values to amounts typical of normal human skin fibroblasts in a dose-dependent fashion. Basic fibroblast growth factor (100 ng/ml) alone or in combination with TGF-beta 1 reduced elastin production and mRNA expression in CL skin fibroblasts more extensively than in normal cells. In situ hybridization showed that these effects were at the transcript level. One of the CL strains was examined in detail. Transcription rates for elastin were similar in normal and CL and unchanged by TGF-beta 1 or TGF-beta 2 (10 ng/ml), while in CL elastin mRNA half-life was increased > 10-fold by TGF-beta 2 and reduced 6-fold after TGF-beta 2 withdrawal, as compared with a control strain. Cycloheximide partially reversed elastin mRNA instability. These data are consistent with a defect in elastin mRNA stability that requires synthesis of labile factors or intact translational machinery, resulting in an extremely low steady state level of mRNA present in this strain of CL. Furthermore, TGF-beta can relieve elastin mRNA instability in at least one CL strain and elastin production defects in both CL strains. Images PMID:7884000

  13. The Nexus of Prematurity, Birth Defects, and Intrauterine Growth Restriction: A Role for Plac1-Regulated Pathways

    PubMed Central

    Fant, Michael E.; Fuentes, Juan; Kong, Xiaoyuan; Jackman, Suzanne

    2013-01-01

    Epidemiological studies have demonstrated an increased prevalence of birth defects and intrauterine growth restriction (IUGR) among infants born prematurely suggesting they share common biological determinants. The identification of key regulatory pathways contributing to this nexus is essential to ongoing efforts to develop effective intervention strategies. Plac1 is a paternally imprinted and X-linked gene that conforms to this paradigm. Examination of a mutant mouse model has confirmed that Plac1 is essential for normal placental development and function. Moreover, it is expressed throughout the developing embryo indicating that it also has broad relevance to embryogenesis. Most notably, its absence in the developing embryo is associated with abnormal brain development and an increased risk of lethal, postnatal hydrocephalus identifying it as a novel, X-linked determinant of brain development. The essential and non-redundant roles of Plac1 in placental and neurological development represent a novel regulatory paradigm for embryonic growth and pregnancy maintenance. Regulatory pathways influenced, in part, by Plac1 are likely to contribute to the observed nexus of IUGR, prematurity, and birth defects. PMID:24600606

  14. In β-actin knockouts, epigenetic reprogramming and rDNA transcription inactivation lead to growth and proliferation defects.

    PubMed

    Almuzzaini, Bader; Sarshad, Aishe A; Rahmanto, Aldwin S; Hansson, Magnus L; Von Euler, Anne; Sangfelt, Olle; Visa, Neus; Farrants, Ann-Kristin Östlund; Percipalle, Piergiorgio

    2016-08-01

    Actin and nuclear myosin 1 (NM1) are regulators of transcription and chromatin organization. Using a genome-wide approach, we report here that β-actin binds intergenic and genic regions across the mammalian genome, associated with both protein-coding and rRNA genes. Within the rDNA, the distribution of β-actin correlated with NM1 and the other subunits of the B-WICH complex, WSTF and SNF2h. In β-actin(-/-) mouse embryonic fibroblasts (MEFs), we found that rRNA synthesis levels decreased concomitantly with drops in RNA polymerase I (Pol I) and NM1 occupancies across the rRNA gene. Reintroduction of wild-type β-actin, in contrast to mutated forms with polymerization defects, efficiently rescued rRNA synthesis underscoring the direct role for a polymerization-competent form of β-actin in Pol I transcription. The rRNA synthesis defects in the β-actin(-/-) MEFs are a consequence of epigenetic reprogramming with up-regulation of the repressive mark H3K4me1 (monomethylation of lys4 on histone H3) and enhanced chromatin compaction at promoter-proximal enhancer (T0 sequence), which disturb binding of the transcription factor TTF1. We propose a novel genome-wide mechanism where the polymerase-associated β-actin synergizes with NM1 to coordinate permissive chromatin with Pol I transcription, cell growth, and proliferation.-Almuzzaini, B., Sarshad, A. A. , Rahmanto, A. S., Hansson, M. L., Von Euler, A., Sangfelt, O., Visa, N., Farrants, A.-K. Ö., Percipalle, P. In β-actin knockouts, epigenetic reprogramming and rDNA transcription inactivation lead to growth and proliferation defects. PMID:27127100

  15. [Research advances in denitrogenation characteristics of aerobic denitrifiers].

    PubMed

    Liang, Shu-Cheng; Zhao, Min; Lu, Lei; Zhao, Li-Yan

    2010-06-01

    The discovery of aerobic denitrifiers is the enrichment and breakthrough of traditional denitrification theory. Owing to their unique superiority in denitrogenation, aerobic denitrifiers have become a hotspot in the study of bio-denitrogenation of waste water. Under aerobic conditions, the aerobic denitrifiers can utilize organic carbon sources for their growth, and produce N2 from nitrate and nitrite. Most of the denitrifiers can also proceed with heterotrophic nitrification simultaneously, transforming NH4(+)-N to gaseous nitrogen. In this paper, the denitrogenation characteristics and action mechanisms of some isolated aerobic denitrifiers were discussed from the aspects of electron theory and denitrifying enzyme system. The effects of the environmental factors DO, carbon sources, and C/N on the denitrogenation process of aerobic denitrifiers were analyzed, and the screening methods as well as the present and potential applications of aerobic denitrifiers in wastewater treatment were described and discussed. PMID:20873638

  16. Impact of ArcA loss in Shewanella oneidensis revealed by comparative proteomics under aerobic and anaerobic conditions

    SciTech Connect

    Yuan, Jie; Wei, Buyun; Lipton, Mary S.; Gao, Haichun

    2012-06-01

    Shewanella inhabit a wide variety of niches in nature and can utilize a broad spectrum of electron acceptors under anaerobic conditions. How they modulate their gene expression to adapt is poorly understood. ArcA, homologue of a global regulator controlling hundreds of genes involved in aerobic and anaerobic respiration in E. coli, was shown to be important in aerobiosis/anaerobiosis of S. oneidensis as well. Loss of ArcA, in addition to altering transcription of many genes, resulted in impaired growth under aerobic condition, which was not observed in E. coli. To further characterize the impact of ArcA loss on gene expression on the level of proteome under aerobic and anaerobic conditions, liquid-chromatography-mass-spectrometry (LC-MS) based proteomic approach was employed. Results show that ArcA loss led to globally altered gene expression, generally consistent with that observed with transcripts. Comparison of transcriptomic and proteomic data permitted identification of 17 high-confidence ArcA targets. Moreover, our data indicate that ArcA is required for regulation of cytochrome c proteins, and the menaquinone level may play a role in regulating ArcA as in E. coli. Proteomic-data-guided growth assay revealed that the aerobic growth defect of ArcA mutant is presumably due to impaired peptide utilization.

  17. Fibroblast Growth Factor-2 Isoform (Low Molecular Weight/18 kDa) Overexpression in Preosteoblast Cells Promotes Bone Regeneration in Critical Size Calvarial Defects in Male Mice

    PubMed Central

    Xiao, Liping; Ueno, Daisuke; Catros, Sylvain; Homer-Bouthiette, Collin; Charles, Lyndon; Kuhn, Liisa

    2014-01-01

    Repair of bone defects remains a significant clinical problem. Bone morphogenetic protein 2 (BMP2) is US Food and Drug Administration–approved for fracture healing but is expensive and has associated morbidity. Studies have shown that targeted overexpression of the 18-kDa low-molecular-weight fibroblast growth factor 2 isoform (LMW) by the osteoblastic lineage of transgenic mice increased bone mass. This study tested the hypotheses that overexpression of LMW would directly enhance healing of a critical size calvarial bone defect in mice and that this overexpression would have a synergistic effect with low-dose administration of BMP2 on critical size calvarial bone defect healing. Bilateral calvarial defects were created in LMW transgenic male mice and control/vector transgenic (Vector) male mice and scaffold with or without BMP2 was placed into the defects. New bone formation was assessed by VIVA-computed tomography of live animals over a 27-week period. Radiographic and computed tomography analysis revealed that at all time points, healing of the defect was enhanced in LMW mice compared with that in Vector mice. Although the very low concentration of BMP2 did not heal the defect in Vector mice, it resulted in complete healing of the defect in LMW mice. Histomorphometric and gene analysis revealed that targeted overexpression of LMW in osteoblast precursors resulted in enhanced calvarial defect healing due to increased osteoblast activity and increased canonical Wnt signaling. PMID:24424065

  18. Growth mechanisms and defects in boronated CVD diamond as identified by scanning tunneling microscopy

    SciTech Connect

    Kreutz, T.J.; Clausing, R.E.; Heatherly, L. Jr.; Warmack, R.J.; Thundat, T.; Feigerle, C.S.; Wandelt, K.

    1995-05-15

    Boron-doped CVD-diamond films were grown in a simple hot filament reactor. A set of samples grown using various methane-in-hydrogen concentrations has been examined by scanning tunneling microscopy in air. On the diamond (111) crystal faces monoatomic steps could be observed giving evidence for layer growth. At low CH{sub 4} concentrations the layers form triangular growth spirals. Screw dislocations in the middle of the spirals serve as continuous sources of steps for the layer growth producing (111) faces of high crystal perfection. At higher methane concentrations the crystal perfection declines and the (111) crystal faces exhibit a mosaic structure. The size of the subgrains in the mosaic pattern decreases with increasing CH{sub 4} concentration. Nucleation of new layers takes place at the subgrain boundaries. The topography of (001) crystal faces did not significantly change with the methane-in-hydrogen concentration and did not allow the determination of the underlying growth mechanism.

  19. Nucleation and growth of intragranular defect and insoluble atom clusters in nuclear oxide fuels

    NASA Astrophysics Data System (ADS)

    Garcia, P.; Martin, G.; Sabathier, C.; Carlot, G.; Michel, A.; Martin, P.; Dorado, B.; Freyss, M.; Bertolus, M.; Skorek, R.; Noirot, J.; Noirot, L.; Kaitasov, O.; Maillard, S.

    2012-04-01

    Uranium and plutonium oxides are subjected to high levels of radiation damage due to the slowing of fission fragments. In addition the composition of the material evolves over time as a result of fission events. Rare gases which constitute an abundant class of fission products are particularly insoluble and therefore tend either to be released from the fuel or form small nanometre size clusters. Bubbles are liable to grow and become trapping sites for migrating defects or other insoluble atoms. Interactions between migrating atoms, defects and existing clusters will determine the rate and extent to which clusters grow. Because the transfer of gas from within the grain to the grain boundaries is thought of as being the rate limiting process for fission gas release, a review of phenomena occurring on the sub-grain scale is carried out. The microstructural modifications induced by neutron irradiations of UO2 fuels are discussed with an emphasis on their relation to fission gas release. Based mainly on TEM studies, the phenomena which are usually taken into account in fission gas behaviour models are looked at and the limitations of these models outlined. More recent experimental and modelling approaches involving ion-irradiation experiments and atomic scale modelling are presented. It is shown that combining these approaches may lead, despite the complexity inherent to the system, to a better understanding of basic radiation induced microstructural changes, clustering events, and rare gas behaviour.

  20. The Mycobacterium tuberculosis H37Ra gene MRA_1916 causes growth defects upon down-regulation.

    PubMed

    Singh, Kumar Sachin; Singh, Sudheer Kumar

    2015-01-01

    D-amino acid oxidases play an important role in converting D-amino acids to their corresponding α-keto acids. MRA_1916 of Mycobacterium tuberculosis H37Ra (Mtb-Ra) is annotated to be a D-amino acid oxidase (DAO). However, not much information is available about its physiological role during Mtb-Ra growth and survival. The present study was taken-up to understand the role of DAO during different stages of growth and effect of its down-regulation on growth. Recombinant Mtb-Ra strains with DAO and GlcB (malate synthase: MRA_1848) gene knockdown were developed and their growth was studied using Microtiter Alamar Blue Assay (MABA) with glycerol, acetate and glycine as a carbon source. Ethyl bromopyruvate (BrP) was used as an inhibitor of GlcB. MABA study showed inhibition of wild-type (WT) and knockdowns in the presence of BrP (2.5mM). However, growth inhibition of WT was less noticeable at lower concentrations of BrP. Mtb-Ra with DAO knockdown showed poor utilization of glycine in the presence of BrP. The DAO localization study showed its prominent distribution in cytosolic fraction and to some extent in cell wall and membrane fractions. Growth profile of WT under oxygen and nutritional stress showed changes in expression of DAO, GlcB, PckA (phosphoenolpyruvate carboxykinase: MRA_0219) and GlyA1 (serine hydroxymethyltransferase: MRA_1104). PMID:26531045

  1. The Mycobacterium tuberculosis H37Ra gene MRA_1916 causes growth defects upon down-regulation

    PubMed Central

    Singh, Kumar Sachin; Singh, Sudheer Kumar

    2015-01-01

    D-amino acid oxidases play an important role in converting D-amino acids to their corresponding α-keto acids. MRA_1916 of Mycobacterium tuberculosis H37Ra (Mtb-Ra) is annotated to be a D-amino acid oxidase (DAO). However, not much information is available about its physiological role during Mtb-Ra growth and survival. The present study was taken-up to understand the role of DAO during different stages of growth and effect of its down-regulation on growth. Recombinant Mtb-Ra strains with DAO and GlcB (malate synthase: MRA_1848) gene knockdown were developed and their growth was studied using Microtiter Alamar Blue Assay (MABA) with glycerol, acetate and glycine as a carbon source. Ethyl bromopyruvate (BrP) was used as an inhibitor of GlcB. MABA study showed inhibition of wild-type (WT) and knockdowns in the presence of BrP (2.5mM). However, growth inhibition of WT was less noticeable at lower concentrations of BrP. Mtb-Ra with DAO knockdown showed poor utilization of glycine in the presence of BrP. The DAO localization study showed its prominent distribution in cytosolic fraction and to some extent in cell wall and membrane fractions. Growth profile of WT under oxygen and nutritional stress showed changes in expression of DAO, GlcB, PckA (phosphoenolpyruvate carboxykinase: MRA_0219) and GlyA1 (serine hydroxymethyltransferase: MRA_1104). PMID:26531045

  2. Aerobic microbial enhanced oil recovery

    SciTech Connect

    Torsvik, T.; Gilje, E.; Sunde, E.

    1995-12-31

    In aerobic MEOR, the ability of oil-degrading bacteria to mobilize oil is used to increase oil recovery. In this process, oxygen and mineral nutrients are injected into the oil reservoir in order to stimulate growth of aerobic oil-degrading bacteria in the reservoir. Experiments carried out in a model sandstone with stock tank oil and bacteria isolated from offshore wells showed that residual oil saturation was lowered from 27% to 3%. The process was time dependent, not pore volume dependent. During MEOR flooding, the relative permeability of water was lowered. Oxygen and active bacteria were needed for the process to take place. Maximum efficiency was reached at low oxygen concentrations, approximately 1 mg O{sub 2}/liter.

  3. Role of defects in the process of graphene growth on hexagonal boron nitride from atomic carbon

    SciTech Connect

    Dabrowski, J. Lippert, G.; Schroeder, T.; Lupina, G.

    2014-11-10

    Hexagonal boron nitride (h-BN) is an attractive substrate for graphene, as the interaction between these materials is weak enough for high carrier mobility to be retained in graphene but strong enough to allow for some epitaxial relationship. We deposited graphene on exfoliated h-BN by molecular beam epitaxy (MBE), we analyzed the atomistic details of the process by ab initio density functional theory (DFT), and we linked the DFT and MBE results by random walk theory. Graphene appears to nucleate around defects in virgin h-BN. The DFT analysis reveals that sticking of carbon to perfect h-BN is strongly reduced by desorption, so that pre-existing seeds are needed for the nucleation. The dominant nucleation seeds are C{sub N}C{sub B} and O{sub N}C{sub N} pairs and B{sub 2}O{sub 3} inclusions in the virgin substrate.

  4. Reversal of axonal growth defects in an extraocular fibrosis model by engineering the kinesin–microtubule interface

    PubMed Central

    Minoura, Itsushi; Takazaki, Hiroko; Ayukawa, Rie; Saruta, Chihiro; Hachikubo, You; Uchimura, Seiichi; Hida, Tomonobu; Kamiguchi, Hiroyuki; Shimogori, Tomomi; Muto, Etsuko

    2016-01-01

    Mutations in human β3-tubulin (TUBB3) cause an ocular motility disorder termed congenital fibrosis of the extraocular muscles type 3 (CFEOM3). In CFEOM3, the oculomotor nervous system develops abnormally due to impaired axon guidance and maintenance; however, the underlying mechanism linking TUBB3 mutations to axonal growth defects remains unclear. Here, we investigate microtubule (MT)-based motility in vitro using MTs formed with recombinant TUBB3. We find that the disease-associated TUBB3 mutations R262H and R262A impair the motility and ATPase activity of the kinesin motor. Engineering a mutation in the L12 loop of kinesin surprisingly restores a normal level of motility and ATPase activity on MTs carrying the R262A mutation. Moreover, in a CFEOM3 mouse model expressing the same mutation, overexpressing the suppressor mutant kinesin restores axonal growth in vivo. Collectively, these findings establish the critical role of the TUBB3-R262 residue for mediating kinesin interaction, which in turn is required for normal axonal growth and brain development. PMID:26775887

  5. A mutation affecting carbon catabolite repression suppresses growth defects in pyruvate carboxylase mutants from Saccharomyces cerevisiae.

    PubMed

    Blázquez, M A; Gamo, F J; Gancedo, C

    1995-12-18

    Yeasts with disruptions in the genes PYC1 and PYC2 encoding the isoenzymes of pyruvate carboxylase cannot grow in a glucose-ammonium medium (Stucka et al. (1991) Mol. Gen. Genet. 229, 307-315). We have isolated a dominant mutation, BPC1-1, that allows growth in this medium of yeasts with interrupted PYC1 and PYC2 genes. The BPC1-1 mutation abolishes catabolite repression of a series of genes and allows expression of the enzymes of the glyoxylate cycle during growth in glucose. A functional glyoxylate cycle is necessary for suppression as a disruption of gene ICL1 encoding isocitrate lyase abolished the phenotypic effect of BPC1-1 on growth in glucose-ammonium. Concurrent expression from constitutive promoters of genes ICL1 and MLS1 (encoding malate synthase) also suppressed the growth phenotype of pyc1 pyc2 mutants. The mutation BPC1-1 is either allelic or closely linked to the mutation DGT1-1. PMID:8543050

  6. Collagen Hydrogel Scaffold and Fibroblast Growth Factor-2 Accelerate Periodontal Healing of Class II Furcation Defects in Dog

    PubMed Central

    Momose, Takehito; Miyaji, Hirofumi; Kato, Akihito; Ogawa, Kosuke; Yoshida, Takashi; Nishida, Erika; Murakami, Syusuke; Kosen, Yuta; Sugaya, Tsutomu; Kawanami, Masamitsu

    2016-01-01

    Objective: Collagen hydrogel scaffold exhibits bio-safe properties and facilitates periodontal wound healing. However, regenerated tissue volume is insufficient. Fibroblast growth factor-2 (FGF2) up-regulates cell behaviors and subsequent wound healing. We evaluated whether periodontal wound healing is promoted by application of collagen hydrogel scaffold in combination with FGF2 in furcation defects in beagle dogs. Methods: Collagen hydrogel was fabricated from bovine type I collagen with an ascorbate-copper ion cross-linking system. Collagen hydrogel was mingled with FGF2 and injected into sponge-form collagen. Subsequently, FGF2 (50 µg)/collagen hydrogel scaffold and collagen hydrogel scaffold alone were implanted into class II furcation defects in dogs. In addition, no implantation was performed as a control. Histometric parameters were assessed at 10 days and 4 weeks after surgery. Result: FGF2 application to scaffold promoted considerable cell and tissue ingrowth containing numerous cells and blood vessel-like structure at day 10. At 4 weeks, reconstruction of alveolar bone was stimulated by implantation of scaffold loaded with FGF2. Furthermore, periodontal attachment, consisting of cementum-like tissue, periodontal ligament-like tissue and Sharpey’s fibers, was also repaired, indicating that FGF2-loaded scaffold guided self-assembly and then re-established the function of periodontal organs. Aberrant healing, such as ankylosis and root resorption, was not observed. Conclusion: FGF2-loaded collagen hydrogel scaffold possessed excellent biocompatibility and strongly promoted periodontal tissue engineering, including periodontal attachment re-organization. PMID:27583044

  7. Loss of the Serine/Threonine Kinase Fused Results in Postnatal Growth Defects and Lethality Due to Progressive Hydrocephalus

    PubMed Central

    Merchant, Mark; Evangelista, Marie; Luoh, Shiuh-Ming; Frantz, Gretchen D.; Chalasani, Sreedevi; Carano, Richard A. D.; van Hoy, Marjie; Ramirez, Julio; Ogasawara, Annie K.; McFarland, Leanne M.; Filvaroff, Ellen H.; French, Dorothy M.; de Sauvage, Frederic J.

    2005-01-01

    The Drosophila Fused (Fu) kinase is an integral component of the Hedgehog (Hh) pathway that helps promote Hh-dependent gene transcription. Vertebrate homologues of Fu function in the Hh pathway in vitro, suggesting that Fu is evolutionarily conserved. We have generated fused (stk36) knockout mice to address the in vivo function of the mouse Fu (mFu) homologue. fused knockouts develop normally, being born in Mendelian ratios, but fail to thrive within 2 weeks, displaying profound growth retardation with communicating hydrocephalus and early mortality. The fused gene is expressed highly in ependymal cells and the choroid plexus, tissues involved in the production and circulation of cerebral spinal fluid (CSF), suggesting that loss of mFu disrupts CSF homeostasis. Similarly, fused is highly expressed in the nasal epithelium, where fused knockouts display bilateral suppurative rhinitis. No obvious defects were observed in the development of organs where Hh signaling is required (limbs, face, bones, etc.). Specification of neuronal cell fates by Hh in the neural tube was normal in fused knockouts, and induction of Hh target genes in numerous tissues is not affected by the loss of mFu. Furthermore, stimulation of fused knockout cerebellar granule cells to proliferate with Sonic Hh revealed no defect in Hh signal transmission. These results show that the mFu homologue is not required for Hh signaling during embryonic development but is required for proper postnatal development, possibly by regulating the CSF homeostasis or ciliary function. PMID:16055717

  8. Management of aerobic vaginitis.

    PubMed

    Tempera, Gianna; Furneri, Pio Maria

    2010-01-01

    Aerobic vaginitis is a new nonclassifiable pathology that is neither specific vaginitis nor bacterial vaginosis. The diversity of this microbiological peculiarity could also explain several therapeutic failures when patients were treated for infections identified as bacterial vaginosis. The diagnosis 'aerobic vaginitis' is essentially based on microscopic examinations using a phase-contrast microscope (at ×400 magnification). The therapeutic choice for 'aerobic vaginitis' should take into consideration an antibiotic characterized by an intrinsic activity against the majority of bacteria of fecal origin, bactericidal effect and poor/absent interference with the vaginal microbiota. Regarding the therapy for aerobic vaginitis when antimicrobial agents are prescribed, not only the antimicrobial spectrum but also the presumed ecological disturbance on the anaerobic and aerobic vaginal and rectal microbiota should be taken into a consideration. Because of their very low impact on the vaginal microbiota, kanamycin or quinolones are to be considered a good choice for therapy. PMID:21051843

  9. Point Defect Distributions in ZnSe Crystals: Effects of Gravity Vector Orientation During Physical Vapor Transport Growth

    NASA Technical Reports Server (NTRS)

    Su, Ching-Hua; Feth, S.; Hirschfeld, D.; Smith, T. M.; Wang, Ling Jun; Volz, M. P.; Lehoczky, S. L.

    1999-01-01

    ZnSe crystals were grown by the physical vapor transport technique under horizontal and vertical (stabilized and destabilized) configurations. Secondary ion mass spectroscopy and photoluminescence measurements were performed on the grown ZnSe samples to map the distributions of [Si], [Fe], [Cu], [Al] and [Li or Na] impurities as well as Zn vacancy, [V (sub Zn)]. Annealings of ZnSe under controlled Zn pressures were studied to correlate the measured photoluminescence emission intensity to the equilibrium Zn partial pressure. In the horizontal grown crystals the segregations of [Si], [Fe], [Al] and [V (sub Zn)] were observed along the gravity vector direction whereas in the vertically stabilized grown crystal the segregation of these point defects was radially symmetrical. No apparent pattern was observed on the measured distributions in the vertically destabilized grown crystal. The observed segregations in the three growth configurations were interpreted based on the possible buoyancy-driven convection in the vapor phase.

  10. The growth of Paracoccus halodenitrificans in a defined medium

    NASA Technical Reports Server (NTRS)

    Hochstein, L. I.; Tomlinson, G. A.

    1984-01-01

    A synthetic medium, consisting of inorganic salts and any of a number of carbon sources, supported the aerobic growth of Paracoccus halodenitrificans when supplemented with thiamine. The same medium plus a nitrogenous oxide supported anaerobic growth when additionally supplemented with methionine. The observation that vitamin B12 or betaine replaced methionine suggested that P. halodenitrificans had a defect in the cobalamin dependent pathway for methionine biosynthesis, as well as the inability to synthesize betanine when growing anaerobically.

  11. The growth of paracoccus halodenitrificans in a defined medium

    NASA Technical Reports Server (NTRS)

    Hochstein, L. I.; Tomlinson, G. A.

    1983-01-01

    A synthetic medium, consisting of inorganic salts and any of a number of carbon sources, supported the aerobic growth of Paracoccus halodenitrificans when supplemented with thiamine. The same medium plus a nitrogenous oxide supported anaerobic growth when additionally supplemented with methionine. The observation that vitamin B12 or betaine replaced methionine suggested that P. halodenitrificans had a defect in the cobalamin dependent pathway for methionine biosynthesis, as well as the inability to synthesize betaine when growing anaerobically.

  12. Deletion of the cardiolipin-specific phospholipase Cld1 rescues growth and life span defects in the tafazzin mutant: implications for Barth syndrome.

    PubMed

    Ye, Cunqi; Lou, Wenjia; Li, Yiran; Chatzispyrou, Iliana A; Hüttemann, Maik; Lee, Icksoo; Houtkooper, Riekelt H; Vaz, Frédéric M; Chen, Shuliang; Greenberg, Miriam L

    2014-02-01

    Cardiolipin (CL) that is synthesized de novo is deacylated to monolysocardiolipin (MLCL), which is reacylated by tafazzin. Remodeled CL contains mostly unsaturated fatty acids. In eukaryotes, loss of tafazzin leads to growth and respiration defects, and in humans, this results in the life-threatening disorder Barth syndrome. Tafazzin deficiency causes a decrease in the CL/MLCL ratio and decreased unsaturated CL species. Which of these biochemical outcomes contributes to the physiological defects is not known. Yeast cells have a single CL-specific phospholipase, Cld1, that can be exploited to distinguish between these outcomes. The cld1Δ mutant has decreased unsaturated CL, but the CL/MLCL ratio is similar to that of wild type cells. We show that cld1Δ rescues growth, life span, and respiratory defects of the taz1Δ mutant. This suggests that defective growth and respiration in tafazzin-deficient cells are caused by the decreased CL/MLCL ratio and not by a deficiency in unsaturated CL. CLD1 expression is increased during respiratory growth and regulated by the heme activator protein transcriptional activation complex. Overexpression of CLD1 leads to decreased mitochondrial respiration and growth and instability of mitochondrial DNA. However, ATP concentrations are maintained by increasing glycolysis. We conclude that transcriptional regulation of Cld1-mediated deacylation of CL influences energy metabolism by modulating the relative contribution of glycolysis and respiration. PMID:24318983

  13. Pravastatin ameliorates placental vascular defects, fetal growth, and cardiac function in a model of glucocorticoid excess.

    PubMed

    Wyrwoll, Caitlin S; Noble, June; Thomson, Adrian; Tesic, Dijana; Miller, Mark R; Rog-Zielinska, Eva A; Moran, Carmel M; Seckl, Jonathan R; Chapman, Karen E; Holmes, Megan C

    2016-05-31

    Fetoplacental glucocorticoid overexposure is a significant mechanism underlying fetal growth restriction and the programming of adverse health outcomes in the adult. Placental glucocorticoid inactivation by 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2) plays a key role. We previously discovered that Hsd11b2(-/-) mice, lacking 11β-HSD2, show marked underdevelopment of the placental vasculature. We now explore the consequences for fetal cardiovascular development and whether this is reversible. We studied Hsd11b2(+/+), Hsd11b2(+/-), and Hsd11b2(-/-) littermates from heterozygous (Hsd11b(+/-)) matings at embryonic day (E)14.5 and E17.5, where all three genotypes were present to control for maternal effects. Using high-resolution ultrasound, we found that umbilical vein blood velocity in Hsd11b2(-/-) fetuses did not undergo the normal gestational increase seen in Hsd11b2(+/+) littermates. Similarly, the resistance index in the umbilical artery did not show the normal gestational decline. Surprisingly, given that 11β-HSD2 absence is predicted to initiate early maturation, the E/A wave ratio was reduced at E17.5 in Hsd11b2(-/-) fetuses, suggesting impaired cardiac function. Pravastatin administration from E6.5, which increases placental vascular endothelial growth factor A and, thus, vascularization, increased placental fetal capillary volume, ameliorated the aberrant umbilical cord velocity, normalized fetal weight, and improved the cardiac function of Hsd11b2(-/-) fetuses. This improved cardiac function occurred despite persisting indications of increased glucocorticoid exposure in the Hsd11b2(-/-) fetal heart. Thus, the pravastatin-induced enhancement of fetal capillaries within the placenta and the resultant hemodynamic changes correspond with restored fetal cardiac function. Statins may represent a useful therapeutic approach to intrauterine growth retardation due to placental vascular hypofunction. PMID:27185937

  14. Correlation of growth temperature with stress, defect states and electronic structure in an epitaxial GaN film grown on c-sapphire via plasma MBE.

    PubMed

    Krishna, Shibin; Aggarwal, Neha; Mishra, Monu; Maurya, K K; Singh, Sandeep; Dilawar, Nita; Nagarajan, Subramaniyam; Gupta, Govind

    2016-03-21

    The relationship of the growth temperature with stress, defect states, and electronic structure of molecular beam epitaxy grown GaN films on c-plane (0001) sapphire substrates is demonstrated. A minimum compressively stressed GaN film is grown by tuning the growth temperature. The correlation of dislocations/defects with the stress relaxation is scrutinized by high-resolution X-ray diffraction and photoluminescence measurements which show a high crystalline quality with significant reduction in the threading dislocation density and defect related bands. A substantial reduction in yellow band related defect states is correlated with the stress relaxation in the grown film. Temperature dependent Raman analysis shows the thermal stability of the stress relaxed GaN film which further reveals a downshift in the E2 (high) phonon frequency owing to the thermal expansion of the lattice at elevated temperatures. Electronic structure analysis reveals that the Fermi level of the films is pinned at the respective defect states; however, for the stress relaxed film it is located at the charge neutrality level possessing the lowest electron affinity. The analysis demonstrates that the generated stress not only affects the defect states, but also the crystal quality, surface morphology and electronic structure/properties. PMID:26916430

  15. Lack of correlation between natural killer activity and tumor growth control in nude mice with different immune defects.

    PubMed

    Fodstad, O; Hansen, C T; Cannon, G B; Statham, C N; Lichtenstein, G R; Boyd, M R

    1984-10-01

    To elucidate the in vivo role of natural killer (NK) cells, the growth of several murine and human tumors was studied in four variants of athymic, nude mice with different levels of NK activity. Beige-nude mice, homozygous for both the beige and the nude genes, had very low levels of NK activity, and their response to the B-cell mitogen, bacterial lipopolysaccharide, was lower than that of high-NK, adult NIH nude mice. Young and adult NIH nudes had different NK levels and showed different response in assays for K-cell, T-cell, and B-cell activity. The B-cell-defective NIH-II mice had slightly lower NK levels than adult NIH animals, but much lower response in the antibody-dependent cell-mediated cytotoxicity assay. No correlation was found between host NK activity and the s.c. growth of various human (LOX, CEM, K562) and murine (YAC-1) tumor cells. Low NK activity was not associated with increased lung colony formation in a metastasis model using i.v.-injected human (LOX) and murine (B16F10) melanoma cells. No relationship was found between host NK activity and the rate of elimination of i.v.-injected 5-iodo-2'-deoxyuridine-labeled LOX, B16F10, and YAC-1 cells from lungs, liver, or spleen. The results fail to support the view that NK cells exert significant direct effects on tumor cells in vivo. PMID:6467201

  16. The repair of full-thickness articular cartilage defects. Immune responses to reparative tissue formed by allogeneic growth plate chondrocyte implants

    SciTech Connect

    Kawabe, N.; Yoshinao, M. )

    1991-07-01

    Growth plate cartilage cultivated in vitro was attached with a fibrin clot to a full-thickness articular cartilage defect on knee joints in allogeneic New Zealand rabbits. The healing of the defects was assessed by gross examination, light microscopy, and immunologic analysis for 24 weeks. Immunologic assessment of cell-mediated immunity, cytotoxicity of a humoral antibody by a 51 chromium release assay, and immunofluorescence studies were carried out. During the first two weeks following grafting, healing was excellent in 11 of the 17 defects. From three to 24 weeks, 11 of 42 defects examined had good results. Host lymphocytes had accumulated around the allograft at two to 12 weeks. Most of the implanted cartilage grown in vitro died and was replaced by fibrous tissue. The immunologic studies suggested that the implanted cartilage began to degenerate two to three weeks after implantation partially because of a humoral immune response but more importantly because of cell-mediated cytotoxicity.

  17. Is Growth Differentiation Factor 11 a Realistic Therapeutic for Aging-Dependent Muscle Defects?

    PubMed

    Harper, Shavonn C; Brack, Andrew; MacDonnell, Scott; Franti, Michael; Olwin, Bradley B; Bailey, Beth A; Rudnicki, Michael A; Houser, Steven R

    2016-04-01

    This "Controversies in Cardiovascular Research" article evaluates the evidence for and against the hypothesis that the circulating blood level of growth differentiation factor 11 (GDF11) decreases in old age and that restoring normal GDF11 levels in old animals rejuvenates their skeletal muscle and reverses pathological cardiac hypertrophy and cardiac dysfunction. Studies supporting the original GDF11 hypothesis in skeletal and cardiac muscle have not been validated by several independent groups. These new studies have either found no effects of restoring normal GDF11 levels on cardiac structure and function or have shown that increasing GDF11 or its closely related family member growth differentiation factor 8 actually impairs skeletal muscle repair in old animals. One possible explanation for what seems to be mutually exclusive findings is that the original reagent used to measure GDF11 levels also detected many other molecules so that age-dependent changes in GDF11 are still not well known. The more important issue is whether increasing blood [GDF11] repairs old skeletal muscle and reverses age-related cardiac pathologies. There are substantial new and existing data showing that GDF8/11 can exacerbate rather than rejuvenate skeletal muscle injury in old animals. There is also new evidence disputing the idea that there is pathological hypertrophy in old C57bl6 mice and that GDF11 therapy can reverse cardiac pathologies. Finally, high [GDF11] causes reductions in body and heart weight in both young and old animals, suggestive of a cachexia effect. Our conclusion is that elevating blood levels of GDF11 in the aged might cause more harm than good. PMID:27034276

  18. Pancreatic ductal adenocarcinoma mice lacking mucin 1 have a profound defect in tumor growth and metastasis.

    PubMed

    Besmer, Dahlia M; Curry, Jennifer M; Roy, Lopamudra D; Tinder, Teresa L; Sahraei, Mahnaz; Schettini, Jorge; Hwang, Sun-Il; Lee, Yong Y; Gendler, Sandra J; Mukherjee, Pinku

    2011-07-01

    MUC1 is overexpressed and aberrantly glycosylated in more than 60% of pancreatic ductal adenocarcinomas. The functional role of MUC1 in pancreatic cancer has yet to be fully elucidated due to a dearth of appropriate models. In this study, we have generated mouse models that spontaneously develop pancreatic ductal adenocarcinoma (KC), which are either Muc1-null (KCKO) or express human MUC1 (KCM). We show that KCKO mice have significantly slower tumor progression and rates of secondary metastasis, compared with both KC and KCM. Cell lines derived from KCKO tumors have significantly less tumorigenic capacity compared with cells from KCM tumors. Therefore, mice with KCKO tumors had a significant survival benefit compared with mice with KCM tumors. In vitro, KCKO cells have reduced proliferation and invasion and failed to respond to epidermal growth factor, platelet-derived growth factor, or matrix metalloproteinase 9. Further, significantly less KCKO cells entered the G(2)-M phase of the cell cycle compared with the KCM cells. Proteomics and Western blotting analysis revealed a complete loss of cdc-25c expression, phosphorylation of mitogen-activated protein kinase (MAPK), as well as a significant decrease in nestin and tubulin-α2 chain expression in KCKO cells. Treatment with a MEK1/2 inhibitor, U0126, abrogated the enhanced proliferation of the KCM cells but had minimal effect on KCKO cells, suggesting that MUC1 is necessary for MAPK activity and oncogenic signaling. This is the first study to utilize a Muc1-null PDA mouse to fully elucidate the oncogenic role of MUC1, both in vivo and in vitro. PMID:21558393

  19. Teaching Aerobic Lifestyles: New Perspectives.

    ERIC Educational Resources Information Center

    Goodrick, G. Ken; Iammarino, Nicholas K.

    1982-01-01

    New approaches to teaching aerobic life-styles in secondary schools are suggested, focusing on three components: (1) the psychological benefits of aerobic activity; (2) alternative aerobic programs at nonschool locations; and (3) the development of an aerobics curriculum to help maintain an active life-style after graduation. (JN)

  20. Effect of insulin-like growth factor-1 and hyaluronic acid in experimentally produced osteochondral defects in rats

    PubMed Central

    Alemdar, Celil; Yücel, İstemi; Erbil, Barış; Erdem, Havva; Atiç, Ramazan; Özkul, Emin

    2016-01-01

    Background: The common purpose of almost all methods used to treat the osteochondral injuries is to produce a normal cartilage matrix. However current methods are not sufficient to provide a normal cartilage matrix. For that reason, researchers have studied to increase the effectiveness of this methods using chondrogenic and chondroprotective molecules in recent experimental studies. Insulin-like growth factor-1 (IGF-1) and hyaluronic acid (HA) are two important agents used in this field. This study compared the effects of IGF-1 and HA in an experimental osteochondral defect in rat femora. Materials and Methods: The rats were divided into three groups (n = 15 per group) as follows: The IGF-1 group, HA group, and control group. An osteochondral defect of a diameter of 1.5 mm and a depth of 2 mm was created on the patellar joint side of femoral condyles. The IGF-1 group received an absorbable gelatin sponge soaked with 15 μg/15 μl of IGF-1, and the HA group received an absorbable gelatin sponge soaked with 80 μg HA. The control group received only an absorbable gelatin sponge. Rats were sacrificed at the 6th week, and the femur condyles were evaluated histologically. Results: According to the total Mankin scale, there was a statistically significant difference between IGF-1 and HA groups and between IGF-1 and control groups. There was also a significant statistical difference between HA and control groups. Conclusion: It was shown histopathologically that IGF-1 is an effective molecule for osteochondral lesions. Although it is weaker than IGF-1, HA also strengthened the repair tissue. PMID:27512224

  1. Aerobic Conditioning Class.

    ERIC Educational Resources Information Center

    Johnson, Neil R.

    1980-01-01

    An aerobic exercise class that focuses on the conditioning of the cardiovascular and muscular systems is presented. Students complete data cards on heart rate, pulse, and exercises to be completed during the forty minute course. (CJ)

  2. Hyperactive transforming growth factor-β1 signaling potentiates skeletal defects in a neurofibromatosis type 1 mouse model.

    PubMed

    Rhodes, Steven D; Wu, Xiaohua; He, Yongzheng; Chen, Shi; Yang, Hao; Staser, Karl W; Wang, Jiapeng; Zhang, Ping; Jiang, Chang; Yokota, Hiroki; Dong, Ruizhi; Peng, Xianghong; Yang, Xianlin; Murthy, Sreemala; Azhar, Mohamad; Mohammad, Khalid S; Xu, Mingjiang; Guise, Theresa A; Yang, Feng-Chun

    2013-12-01

    Dysregulated transforming growth factor beta (TGF-β) signaling is associated with a spectrum of osseous defects as seen in Loeys-Dietz syndrome, Marfan syndrome, and Camurati-Engelmann disease. Intriguingly, neurofibromatosis type 1 (NF1) patients exhibit many of these characteristic skeletal features, including kyphoscoliosis, osteoporosis, tibial dysplasia, and pseudarthrosis; however, the molecular mechanisms mediating these phenotypes remain unclear. Here, we provide genetic and pharmacologic evidence that hyperactive TGF-β1 signaling pivotally underpins osseous defects in Nf1(flox/-) ;Col2.3Cre mice, a model which closely recapitulates the skeletal abnormalities found in the human disease. Compared to controls, we show that serum TGF-β1 levels are fivefold to sixfold increased both in Nf1(flox/-) ;Col2.3Cre mice and in a cohort of NF1 patients. Nf1-deficient osteoblasts, the principal source of TGF-β1 in bone, overexpress TGF-β1 in a gene dosage-dependent fashion. Moreover, Nf1-deficient osteoblasts and osteoclasts are hyperresponsive to TGF-β1 stimulation, potentiating osteoclast bone resorptive activity while inhibiting osteoblast differentiation. These cellular phenotypes are further accompanied by p21-Ras-dependent hyperactivation of the canonical TGF-β1-Smad pathway. Reexpression of the human, full-length neurofibromin guanosine triphosphatase (GTPase)-activating protein (GAP)-related domain (NF1 GRD) in primary Nf1-deficient osteoblast progenitors, attenuated TGF-β1 expression levels and reduced Smad phosphorylation in response to TGF-β1 stimulation. As an in vivo proof of principle, we demonstrate that administration of the TGF-β receptor 1 (TβRI) kinase inhibitor, SD-208, can rescue bone mass deficits and prevent tibial fracture nonunion in Nf1(flox/-) ;Col2.3Cre mice. In sum, these data demonstrate a pivotal role for hyperactive TGF-β1 signaling in the pathogenesis of NF1-associated osteoporosis and pseudarthrosis, thus implicating the TGF

  3. Growth temperature dependence of Si doping efficiency and compensating deep level defect incorporation in Al{sub 0.7}Ga{sub 0.3}N

    SciTech Connect

    Armstrong, Andrew M. Moseley, Michael W.; Allerman, Andrew A.; Crawford, Mary H.; Wierer, Jonathan J.

    2015-05-14

    The growth temperature dependence of Si doping efficiency and deep level defect formation was investigated for n-type Al{sub 0.7}Ga{sub 0.3}N. It was observed that dopant compensation was greatly reduced with reduced growth temperature. Deep level optical spectroscopy and lighted capacitance-voltage were used to understand the role of acceptor-like deep level defects on doping efficiency. Deep level defects were observed at 2.34 eV, 3.56 eV, and 4.74 eV below the conduction band minimum. The latter two deep levels were identified as the major compensators because the reduction in their concentrations at reduced growth temperature correlated closely with the concomitant increase in free electron concentration. Possible mechanisms for the strong growth temperature dependence of deep level formation are considered, including thermodynamically driven compensating defect formation that can arise for a semiconductor with very large band gap energy, such as Al{sub 0.7}Ga{sub 0.3}N.

  4. Influence of defects in the output power of c- and a-axis growth Nd:YVO4 single laser crystals

    NASA Astrophysics Data System (ADS)

    Shawley, Charles R.; Wang, Cai-Lin; Lynn, Kelvin G.

    2006-06-01

    The differences in the output powers of a- and c-axis growth neodymium-doped yttrium orthovanadate (Nd:YVO4) crystals grown by the Czochralski method were investigated. It was found that the differences in the output powers are due to crystal defects, such as veils and grain boundaries, which lead to changes in the thermal and optical properties of Nd:YVO4 and reduce the quality of the laser beam. To relieve internal stresses introduced by the crystal growth process, boules form grain boundaries and other thermodynamically favorable defects in the boule. Because c-axis grown Nd:YVO4 crystals do not contain a slip system, no grain boundaries or ghost veils can form. As a result, c-axis grown boules are highly vulnerable to thermal and stress fractures and require careful growth parameter selection to overcome these defects. However, a-axis grown crystal contain a slip system and can form thermodynamically stable defects including grain boundaries, scatter centers, and ghost veils. In this paper, data are presented showing that properly grown c-axis growth crystal, having no grain boundaries or veils, is more suited for high output power applications than a-axis grown one.

  5. [Research advances in aerobic denitrifiers].

    PubMed

    Wang, Wei; Cai, Zu-cong; Zhong, Wen-hui; Wang, Guo-xiang

    2007-11-01

    This paper reviewed the varieties and characteristics of aerobic denitrifiers, their action mechanisms, and the factors affecting aerobic denitrification. Aerobic denitrifiers mainly include Pseudomonas, Alcaligenes, Paracoccus and Bacillus, which are either aerobic or facultative aerobic, and heterotrophic. They can denitrify under aerobic conditions, with the main product being N2O. They can also convert NH4+ -N to gas product. The nitrate reductase which catalyzes the denitrification is periplasmic nitrate reductase rather than membrane-bound nitrate reductase. Dissolved oxygen concentration and C/N ratio are the main factors affecting aerobic denitrification. The main methods for screening aerobic denitrifiers, such as intermittent aeration and selected culture, were also introduced. The research advances in the application of aerobic denitrifiers in aquaculture, waste water processing, and bio-degradation of organic pollutants, as well as the contributions of aerobic denitrifiers to soil nitrogen emission were summarized. PMID:18260473

  6. Structural study of growth, orientation and defects characteristics in the functional microelectromechanical system material aluminium nitride

    SciTech Connect

    Hrkac, Viktor Schürmann, Ulrich; Kienle, Lorenz; Kobler, Aaron; Kübel, Christian; Marauska, Stephan; Wagner, Bernhard; Petraru, Adrian; Kohlstedt, Hermann; Kiran Chakravadhanula, Venkata Sai; Duppel, Viola; Lotsch, Bettina Valeska

    2015-01-07

    The real structure and morphology of piezoelectric aluminum nitride (AlN) thin films as essential components of magnetoelectric sensors are investigated via advanced transmission electron microscopy methods. State of the art electron diffraction techniques, including precession electron diffraction and automated crystal orientation mapping (ACOM), indicate a columnar growth of the AlN grains optimized for piezoelectric application with a (0 0 0 1) texture. Comparing ACOM with piezoresponse force microscopy measurements, a visual correlation of the structure and the piezoelectric properties is enabled. With a quantitative analysis of the ACOM measurements, a statistical evaluation of grain rotations is performed, indicating the presence of coincidence site lattices with Σ7, Σ13a, Σ13b, Σ25. Using a geometric phase analysis on high resolution micrographs, the occurrence of strain is detected almost exclusively at the grain boundaries. Moreover, high resolution imaging was applied for solving the atomic structure at stacking mismatch boundaries with a displacement vector of 1/2 〈1 0 -1 1〉. All real structural features can be interpreted via simulations based on crystallographic computing in terms of a supercell approach.

  7. SCID dogs: similar transplant potential but distinct intra-uterine growth defects and premature replicative senescence compared with SCID mice.

    PubMed

    Meek, Katheryn; Jutkowitz, Ari; Allen, Lisa; Glover, Jillian; Convery, Erin; Massa, Alisha; Mullaney, Tom; Stanley, Bryden; Rosenstein, Diana; Bailey, Susan M; Johnson, Cheri; Georges, George

    2009-08-15

    We have previously described DNA-dependent protein kinase (DNA-PKcs) mutations in horses and dogs that result in deficits in V(D)J recombination, DNA repair, and SCID. In this paper, we document substantial developmental growth defects in DNA-PKcs-deficient dogs that are not apparent in SCID mice. Fibroblast cell strains derived from either fetal or adult SCID dogs proliferate poorly in culture and undergo premature replicative senescence, somewhat reminiscent of cells derived from Ku-deficient mice. A limited number of animals have been immune reconstituted (by bone marrow transplantation) so that they can be maintained in a normal environment for long periods. Several of these animals have developed conditions associated with premature ageing at 2-3 years of age, roughly 20% of their expected lifespan. These conditions include intestinal malabsorption and primary neural cell neoplasia. These results suggest that DNA-PKcs deficiency is not tolerated equally in all species, perhaps providing insight into why DNA-PKcs deficiency has not been observed in humans. Finally, this study demonstrates the feasibility of maintaining SCID dogs for extended periods of time and documents their utility for bone marrow transplantation studies and as hosts for the propagation of xenografts. In sum, SCID dogs may present researchers with new possibilities for the development of animal models of human disease. PMID:19635917

  8. Cadmium-induced neural tube defects and fetal growth restriction: Association with disturbance of placental folate transport.

    PubMed

    Zhang, Gui-Bin; Wang, Hua; Hu, Jun; Guo, Min-Yin; Wang, Ying; Zhou, Yan; Yu, Zhen; Fu, Lin; Chen, Yuan-Hua; Xu, De-Xiang

    2016-09-01

    Previous studies found that maternal Cd exposure on gestational day (GD)9 caused forelimb ectrodactyly and tail deformity, the characteristic malformations. The aim of the present study was to investigate whether maternal Cd exposure on GD8 induces fetal neural tube defects (NTDs). Pregnant mice were intraperitoneally injected with CdCl2 (2.5 or 5.0mg/kg) on GD8. Neither forelimb ectrodactyly nor tail deformity was observed in mice injected with CdCl2 on GD8. Instead, maternal Cd exposure on GD8 resulted in the incidence of NTDs. Moreover, maternal Cd exposure on GD8 resulted in fetal growth restriction. In addition, maternal Cd exposure on GD8 reduced placental weight and diameter. The internal space of maternal and fetal blood vessels in the labyrinth layer was decreased in the placentas of mice treated with CdCl2. Additional experiment showed that placental PCFT protein and mRNA, a critical folate transporter, was persistently decreased when dams were injected with CdCl2 on GD8. Correspondingly, embryonic folate content was markedly decreased in mice injected with CdCl2 on GD8, whereas Cd had little effect on folate content in maternal serum. Taken together, these results suggest that maternal Cd exposure during organogenesis disturbs transport of folate from maternal circulation to the fetuses through down-regulating placental folate transporters. PMID:27417525

  9. Enhanced photo/electroluminescence properties of Eu-doped GaN through optimization of the growth temperature and Eu related defect environment

    NASA Astrophysics Data System (ADS)

    Zhu, W.; Mitchell, B.; Timmerman, D.; Uedono, A.; Koizumi, A.; Fujiwara, Y.

    2016-05-01

    The influence of growth temperature on the surface morphology and luminescence properties of Eu-doped GaN layers grown by organometallic vapor phase epitaxy was investigated. By using a Eu source that does not contain oxygen in its molecular structure, and varying the growth temperature, the local defect environment around the Eu3+ ions was manipulated, yielding a higher emission intensity from the Eu3+ ions and a smoother sample surface. The optimal growth temperature was determined to be 960 °C and was used to fabricate a GaN-based red light-emitting diode with a significantly higher output power.

  10. Aerobic biodegradation of trichloroethene without auxiliary substrates.

    PubMed

    Schmidt, Kathrin R; Gaza, Sarah; Voropaev, Andrey; Ertl, Siegmund; Tiehm, Andreas

    2014-08-01

    Trichloroethene (TCE) represents a priority pollutant and is among the most frequently detected contaminants in groundwater. The current bioremediation measures have certain drawbacks like e.g. the need for auxiliary substrates. Here, the aerobic biodegradation of TCE as the sole growth substrate is demonstrated. This new process of metabolic TCE degradation was first detected in groundwater samples. TCE degradation was stable in an enriched mixed bacterial culture in mineral salts medium for over five years and repeated transfers of the culture resulting in a 10(10) times dilution of the original groundwater. Aerobic TCE degradation resulted in stoichiometric chloride formation. Stable carbon isotope fractionation was observed providing a reliable analytical tool to assess this new biodegradation process at field sites. The results suggest that aerobic biodegradation of TCE without auxiliary substrate could be considered as an option for natural attenuation or engineered bioremediation of contaminated sites. PMID:24793109

  11. Summary report on the aerobic degradation of diesel fuel and the degradation of toluene under aerobic, denitrifying and sulfate reducing conditions

    SciTech Connect

    Coyne, P.; Smith, G.

    1995-08-15

    This report contains a number of studies that were performed to better understand the technology of the biodegradation of petroleum hydrocarbons. Topics of investigation include the following: diesel fuel degradation by Rhodococcus erythropolis; BTEX degradation by soil isolates; aerobic degradation of diesel fuel-respirometry; aerobic degradation of diesel fuel-shake culture; aerobic toluene degradation by A3; effect of HEPES, B1, and myo-inositol addition on the growth of A3; aerobic and anaerobic toluene degradation by contaminated soils; denitrifying bacteria MPNs; sulfate-reducing bacteria MPNs; and aerobic, DNB and SRB enrichments.

  12. The relationship between crystal growth and defect structure: a study of potassium hydrogen phthalate using x-ray topography and atomic force microscopy

    NASA Astrophysics Data System (ADS)

    Ester, G. R.; Price, R.; Halfpenny, P. J.

    1999-05-01

    An investigation of the defect structure of crystals of potassium hydrogen phthalate (KAP) and its relationship to the crystallization behaviour has been carried out using x-ray diffraction topography and atomic force microscopy (AFM). Crystals of KAP grown from aqueous solution were found to exhibit very low defect densities in the range 5 to 15 cm-2 and remarkably low levels of strain. The character and distribution of the dominant growth dislocation types were determined using x-ray topography. The most significant features of the dislocation structure were a tendency for certain dislocation types to nucleate in pairs and at growth sector boundaries. X-ray topography revealed sectorial variations in solvent inclusions and the complementary use of AFM has shown the relationship of this to growth spiral anisotropy on the (010) face of KAP crystals. Changes in KAP crystal morphology have been observed which result from extreme variations in dislocation density, leading to either spiral growth or, in the case of dislocation-free growth sectors, a two-dimensional nucleation mechanism. The bending of dislocations from one growth sector to another and the tendency of dislocations in this material to nucleate in pairs are discussed in the context of size-dependent crystal growth rates.

  13. Effect of combined administration of transforming growth factor-b1 and insulin-like growth factor I on the mechanical properties of a patellar tendon defect model in rabbits.

    PubMed

    Lyras, Dimitrios N; Kazakos, Konstantinos; Verettas, Dionysios; Chronopoulos, Efstathios; Folaranmi, Semiu; Agrogiannis, George

    2010-06-01

    The aim of this study was to test the hypothesis that combined administration of TGF-b1 and IGF-I in a patellar tendon defect model could enhance the mechanical properties of the healed tendon. Twenty four New Zealand white rabbits were used for this purpose. In each animal, the right knee was used for the application of the growth factors, whereas the left knee served as an untreated control. The growth factors were mixed with fibrin sealant as a delivery vehicle. Two groups of rabbits were sacrificed after 2 weeks and 6 weeks respectively. Application of the growth factors resulted in a significant increase in force at failure, ultimate stress, stiffness, and energy uptake at 2 weeks, whereas none of the parameters revealed any significant difference between the two groups at 6 weeks. This study provides valuable information on the effect of the two growth factors on this patellar tendon defect model. PMID:20698461

  14. Surface defect free growth of a spin dimer TlCuCl3 compound crystals and investigations on its optical and magnetic properties

    NASA Astrophysics Data System (ADS)

    Ryu, Gihun; Son, Kwanghyo

    2016-05-01

    A defect-free high quality single crystal of spin dimer TlCuCl3 compound is firstly synthesized at the optimal growth temperature using the vertical Bridgman method. In this study, we clearly found that the cupric chloride is easily decomposed into the Cl- deficient composition at ≥470 °C. The Cl-- related gas phase at the high temperature region also always gives rise to a pinhole-like surface defect at the surface of crystal. Therefore, we clearly verified an exotic anisotropic magnetic behavior (anisotropic ratio of Mb/M(201) at 2 K, 7 T=10) using the defect-free TlCuCl3 crystals in this three-dimensional spin dimer TlCuCl3 compound, relatively stronger magnetic ordering in the H//b than that of H//(201) direction at above the transition magnetic field.

  15. Defect formation during the initial stage of physical vapor transport growth of 4H-SiC in the [ 11 2 bar 0 ] direction

    NASA Astrophysics Data System (ADS)

    Ohshige, Chikashi; Takahashi, Tatsuya; Ohtani, Noboru; Katsuno, Masakazu; Fujimoto, Tatsuo; Sato, Shinya; Tsuge, Hiroshi; Yano, Takayuki; Matsuhata, Hirofumi; Kitabatake, Makoto

    2014-12-01

    Defect formation during the initial stage of physical vapor transport (PVT) growth of 4H-SiC in the [ 11 2 bar 0 ] direction has been investigated by x-ray reciprocal space mapping (RSM), defect-selective etching, and low-voltage scanning electron microscopy. RSM studies showed that 4H-SiC crystals grown in the [ 11 2 bar 0 ] direction showed a significant degradation of crystalline quality during the initial stage of PVT growth, compared with crystals grown in the [ 000 1 bar ] direction; the growth in the [ 11 2 bar 0 ] direction resulted in a misoriented domain structure near the grown crystal/seed interface. At the interface, high densities of basal plane dislocations, extending parallel to the interface, and threading edge dislocations along the c-axis were observed. The former caused a tilt domain boundary around an axis parallel to [ 1 1 bar 00 ]. Based on the results, the paper discusses the defect formation mechanism during the initial stage of PVT growth in the [ 11 2 bar 0 ] direction and points to the difference in nitrogen concentration between the seed and the grown crystal as a cause of the observed domain and dislocation structure at the grown crystal/seed interface.

  16. A Longitudinal Study of Growth and Development and the Incidence of Physical Defects at Ages 9 and 10. A Progress Report to the Bernard van Leer Foundation on the Growth and Development Study of the Mt. Druitt Longitudinal Study.

    ERIC Educational Resources Information Center

    Clark, Anne; O'Brien, Peter

    A longitudinal comparative study was made of the physical growth and development of Australian fourth-grade students from low, medium, and high socioeconomic groups. Specific questions addressed were (1) Do children differing in socioeconomic status differ in anthropometric characteristics and incidence of physical defects? (2) What is the…

  17. Female predisposition to cranial neural tube defects is not because of a difference between the sexes in the rate of embryonic growth or development during neurulation.

    PubMed Central

    Brook, F A; Estibeiro, J P; Copp, A J

    1994-01-01

    The susceptibility of females to anencephaly is well established and has been suggested to result from a slower rate of growth and development of female embryos during cranial neurulation. We have tested this hypothesis by measuring the rates of growth and development, both in utero and in vitro, of male and female embryos of the curly tail (ct) mutant mouse strain, in which cranial neural tube defects occur primarily in females. Embryonic growth was assessed by increase in protein content, while development progression was judged from increase in somite number and morphological score. Embryos were sexed by use of the polymerase chain reaction to amplify a DNA sequence specific to the Y chromosome, and by sex chromatin analysis. We find that, during neurulation (between 8.5 and 10.5 days of gestation), males are advanced in growth and development relative to their female litter mates, but that the rates of growth and development do not differ between the sexes during this period. We conclude that rate of embryonic growth and development is unlikely to determine susceptibility to cranial neural tube defects. It seems more likely that male and female embryos differ in some specific aspect(s) of the neurulation process that increases the susceptibility of females to development of anencephaly. Images PMID:8064816

  18. Effects of concomitant use of fibroblast growth factor (FGF)-2 with beta-tricalcium phosphate ({beta}-TCP) on the beagle dog 1-wall periodontal defect model

    SciTech Connect

    Anzai, Jun; Kitamura, Masahiro; Nozaki, Takenori; Nagayasu, Toshie; Terashima, Akio; Asano, Taiji; Murakami, Shinya

    2010-12-17

    Research highlights: {yields} Concomitant use of FGF-2 and {beta}-TCP (an osteo-conductive scaffold) significantly promotes periodontal regeneration in the severe periodontitis model (1-wall defect model) of beagle dog. {yields} FGF-2 enhanced new bone formation via {beta}-TCP at the defects. {yields} In particular, FGF-2 dramatically regenerated new periodontal ligament and cementum formations at the defects, that is one of the most important healing outcomes during the process of periodontal regeneration. {yields} Epithelial downgrowth (undesirable wound healing) was decreased by administration of FGF-2. {yields} This manuscript indicates for the first time that concomitant use of FGF-2 and {beta}-TCP is efficacious in regenerating periodontal tissue following severe destruction of the tissue by progression of periodontitis. -- Abstract: The effects of concomitant use of fibroblast growth factor-2 (FGF-2) and beta-tricalcium phosphate ({beta}-TCP) on periodontal regeneration were investigated in the beagle dog 1-wall periodontal defect model. One-wall periodontal defects were created in the mesial portion of both sides of the mandibular first molars, and 0.3% FGF-2 plus {beta}-TCP or {beta}-TCP alone was administered. Radiographic evaluation was performed at 0, 3, and 6 weeks. At 6 weeks, the periodontium with the defect site was removed and histologically analyzed. Radiographic findings showed that co-administration of FGF-2 significantly increased bone mineral contents of the defect sites compared with {beta}-TCP alone. Histologic analysis revealed that the length of the regenerated periodontal ligament, the cementum, distance to the junctional epithelium, new bone height, and area of newly formed bone were significantly increased in the FGF-2 group. No abnormal inflammatory response or ankylosis was observed in either group. These findings indicate the efficacy of concomitant use of FGF-2 and {beta}-TCP as an osteoconductive material for periodontal

  19. Dance--Aerobic and Anaerobic.

    ERIC Educational Resources Information Center

    Cohen, Arlette

    1984-01-01

    This article defines and explains aerobic exercise and its effects on the cardiovascular system. Various studies on dancers are cited indicating that dance is an anaerobic activity with some small degree of aerobic benefit. (DF)

  20. GSK3 inactivation is involved in mitochondrial complex IV defect in transforming growth factor (TGF) {beta}1-induced senescence

    SciTech Connect

    Byun, Hae-Ok; Jung, Hyun-Jung; Seo, Yong-Hak; Lee, Young-Kyoung; Hwang, Sung-Chul; Seong Hwang, Eun; Yoon, Gyesoon

    2012-09-10

    Transforming growth factor {beta}1 (TGF {beta}1) induces Mv1Lu cell senescence by persistently producing mitochondrial reactive oxygen species (ROS) through decreased complex IV activity. Here, we investigated the molecular mechanism underlying the effect of TGF {beta}1 on mitochondrial complex IV activity. TGF {beta}1 progressively phosphorylated the negative regulatory sites of both glycogen synthase kinase 3 (GSK3) {alpha} and {beta}, corresponding well to the intracellular ROS generation profile. Pre-treatment of N-acetyl cysteine, an antioxidant, did not alter this GSK3 phosphorylation (inactivation), whereas pharmacological inhibition of GSK3 by SB415286 significantly increased mitochondrial ROS, implying that GSK3 phosphorylation is an upstream event of the ROS generation. GSK3 inhibition by SB415286 decreased complex IV activity and cellular O{sub 2} consumption rate and eventually induced senescence of Mv1Lu cell. Similar results were obtained with siRNA-mediated knockdown of GSK3. Moreover, we found that GSK3 not only exists in cytosol but also in mitochondria of Mv1Lu cell and the mitochondrial GSK3 binds complex IV subunit 6b which has no electron carrier and is topologically located in the mitochondrial intermembrane space. Involvement of subunit 6b in controlling complex IV activity and overall respiration rate was proved with siRNA-mediated knockdown of subunit 6b. Finally, TGF {beta}1 treatment decreased the binding of the subunit 6b to GSK3 and subunit 6b phosphorylation. Taken together, our results suggest that GSK3 inactivation is importantly involved in TGF {beta}1-induced complex IV defects through decreasing phosphorylation of the subunit 6b, thereby contributing to senescence-associated mitochondrial ROS generation.

  1. An Intracellular Iron Chelator Pleiotropically Suppresses Enzymatic and Growth Defects of Superoxide Dismutase-Deficient Escherichia coli

    PubMed Central

    Maringanti, Sujatha; Imlay, James A.

    1999-01-01

    Mutants of Escherichia coli that lack cytoplasmic superoxide dismutase (SOD) exhibit auxotrophies for sulfur-containing, branched-chain, and aromatic amino acids and cannot catabolize nonfermentable carbon sources. A secondary-site mutation substantially relieved all of these growth defects. The requirement for fermentable carbon and the branched-chain auxotrophy occur because superoxide (O2−) leaches iron from the [4Fe-4S] clusters of a family of dehydratases, thereby inactivating them; the suppression of these phenotypes was mediated by the restoration of activity to these dehydratases, evidently without changing the intracellular concentration of O2−. Cloning, complementation, and sequence analysis identified the suppressor mutation to be in dapD, which encodes tetrahydrodipicolinate succinylase, an enzyme involved in diaminopimelate and lysine biosynthesis. A block in dapB, which encodes dihydrodipicolinate reductase in the same pathway, conferred similar protection. Genetic analysis indicated that the protection stems from the intracellular accumulation of tetrahydro- or dihydrodipicolinate. Heterologous expression in the SOD mutants of the dipicolinate synthase of Bacillus subtilis generated dipicolinate and similarly protected them. Dipicolinates are excellent iron chelators, and their accumulation in the cell triggered derepression of the Fur regulon and a large increase in the intracellular pool of free iron, presumably as a dipicolinate chelate. A fur mutation only partially relieved the auxotrophies, indicating that Fur derepression assists but is not sufficient for suppression. It seems plausible that the abundant internal iron permits efficient reactivation of superoxide-damaged iron-sulfur clusters. This result provides circumstantial evidence that the sulfur and aromatic auxotrophies of SOD mutants are also directly or indirectly linked to iron metabolism. PMID:10368155

  2. Isolation of NAD cycle mutants defective in nicotinamide mononucleotide deamidase in Salmonella typhimurium.

    PubMed

    Cheng, W; Roth, J

    1995-12-01

    The NAD or pyridine nucleotide cycle is the sequence of reactions involved in the breakdown of NAD to nicotinamide mononucleotide (NMN) and regeneration of NAD. This cycle is fivefold more active during aerobic growth of Salmonella typhimurium and under this condition breaks down half of the NAD pool every 90 min. DNA ligase is known to convert NAD to NMN but is only a minor contributor to the NAD cycle during aerobic growth. The dominant aerobic route of NMN formation is otherwise uncharacterized. Accumulated NMN generated by either of these routes is potentially dangerous in that it can inhibit the essential enzyme DNA ligase. The reactions which recycle NMN to NAD may serve to minimize the inhibition of ligase and other enzymes by accumulated NMN. The predominant recycling reaction in S. typhimurium appears to be NMN deamidase, which converts NMN directly to the biosynthetic intermediate nicotinic acid mononucleotide. Mutants defective in this recycling step were isolated and characterized. By starting with a ligase-deficient (lig mutant) parent strain that requires deamidase to assimilate exogenous NMN, two classes of mutants that are unable to grow on minimal NMN media were isolated. One class (pncC) maps at 83.7 min and shows only 2% of the wild-type levels of NMN deamidase. Under aerobic conditions, a lig+ allele allows a pncC mutant to grow on NMN and restores some deamidase activity. This growth ability and enzyme activity are not found in lig+ strains grown without oxygen. This suggests that the existence of a second NMN deamidase (pncL) dependent on ligase and stimulated during aerobic growth. The second class of mutants (pncD) gains a requirement for isoleucine plus valine with growth in the presence of exogenous NMN. We propose that pncD mutations reduce the activity of an ilv biosynthetic enzyme that is naturally sensitive to inhibition by NMN. PMID:7592458

  3. Aerobic Anoxygenic Phototrophic Bacteria

    PubMed Central

    Yurkov, Vladimir V.; Beatty, J. Thomas

    1998-01-01

    The aerobic anoxygenic phototrophic bacteria are a relatively recently discovered bacterial group. Although taxonomically and phylogenetically heterogeneous, these bacteria share the following distinguishing features: the presence of bacteriochlorophyll a incorporated into reaction center and light-harvesting complexes, low levels of the photosynthetic unit in cells, an abundance of carotenoids, a strong inhibition by light of bacteriochlorophyll synthesis, and the inability to grow photosynthetically under anaerobic conditions. Aerobic anoxygenic phototrophic bacteria are classified in two marine (Erythrobacter and Roseobacter) and six freshwater (Acidiphilium, Erythromicrobium, Erythromonas, Porphyrobacter, Roseococcus, and Sandaracinobacter) genera, which phylogenetically belong to the α-1, α-3, and α-4 subclasses of the class Proteobacteria. Despite this phylogenetic information, the evolution and ancestry of their photosynthetic properties are unclear. We discuss several current proposals for the evolutionary origin of aerobic phototrophic bacteria. The closest phylogenetic relatives of aerobic phototrophic bacteria include facultatively anaerobic purple nonsulfur phototrophic bacteria. Since these two bacterial groups share many properties, yet have significant differences, we compare and contrast their physiology, with an emphasis on morphology and photosynthetic and other metabolic processes. PMID:9729607

  4. Aerobic Dance in Public Schools.

    ERIC Educational Resources Information Center

    Chiles, Barbara Ann; Moore, Suzanne

    1981-01-01

    Aerobic dance offers a challenging workout in a social atmosphere. Though some physical education instructors tend to exclude dance units from the curriculum, most could teach aerobic dance if they had a basic knowledge of aerobic routines. The outline for a unit to be used in the class is presented. (JN)

  5. Managing for Improved Aerobic Stability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aerobic deterioration or spoilage of silage is the result of aerobic microorganisms metabolizing components of the silage using oxygen. In the almost 40 years over which these silage conferences have been held, we have come to recognize the typical pattern of aerobic microbial development by which s...

  6. Differential sensitivity of aerobic gram-positive and gram-negative microorganisms to 2,4,6-trinitrotoluene (TNT) leads to dissimilar growth and TNT transformation: Results of soil and pure culture studies

    SciTech Connect

    Fuller, M.E.; Manning, J.F. Jr.

    1996-07-30

    The effects of 2,4,6-trinitrotoluene (TNT) on indigenous soil populations and pure bacterial cultures were examined. The number of colony-forming units (CFU) appearing when TNT-contaminated soil was spread on 0.3% molasses plates decreased by 50% when the agar was amended with 67 {mu}g TNT mL{sup -1}, whereas a 99% reduction was observed when uncontaminated soil was plated. Furthermore, TNT-contaminated soil harbored a greater number of organisms able to grow on plates amended with greater than 10 {mu}g TNT mL{sup -1}. The percentage of gram-positive isolates was markedly less in TNT-contaminated soil (7%; 2 of 30) than in uncontaminated soil (61%; 20 of 33). Pseudomonas aeruginosa, Pseudomonas corrugate, Pseudomonasfluorescens and Alcaligenes xylosoxidans made up the majority of the gram-negative isolates from TNT-contaminated soil. Gram-positive isolates from both soils demonstrated marked growth inhibition when greater than 8-16 {mu}g TNT mL{sup -1} was present in the culture media. Most pure cultures of known aerobic gram-negative organisms readily degraded TNT and evidenced net consumption of reduced metabolites. However, pure cultures of aerobic gram-positive bacteria were sensitive to relatively low concentrations of TNT as indicated by the 50% reduction in growth and TNT transformation which was observed at approximately 10 {mu}g TNT mL{sup -1}. Most non-sporeforming gram-positive organisms incubated in molasses media amended with 80 {mu}g TNT mL{sup -1} or greater became unculturable, whereas all strains tested remained culturable when incubated in mineral media amended with 98 {mu}g TNT mL{sup -1}, indicating that TNT sensitivity is likely linked to cell growth. These results indicate that gram-negative organisms are most likely responsible for any TNT transformation in contaminated soil, due to their relative insensitivity to high TNT concentrations and their ability to transform TNT.

  7. Low Probability of Initiating nirS Transcription Explains Observed Gas Kinetics and Growth of Bacteria Switching from Aerobic Respiration to Denitrification

    PubMed Central

    Hassan, Junaid; Bergaust, Linda L.; Wheat, I. David; Bakken, Lars R.

    2014-01-01

    In response to impending anoxic conditions, denitrifying bacteria sustain respiratory metabolism by producing enzymes for reducing nitrogen oxyanions/-oxides (NOx) to N2 (denitrification). Since denitrifying bacteria are non-fermentative, the initial production of denitrification proteome depends on energy from aerobic respiration. Thus, if a cell fails to synthesise a minimum of denitrification proteome before O2 is completely exhausted, it will be unable to produce it later due to energy-limitation. Such entrapment in anoxia is recently claimed to be a major phenomenon in batch cultures of the model organism Paracoccus denitrificans on the basis of measured e−-flow rates to O2 and NOx. Here we constructed a dynamic model and explicitly simulated actual kinetics of recruitment of the cells to denitrification to directly and more accurately estimate the recruited fraction (). Transcription of nirS is pivotal for denitrification, for it triggers a cascade of events leading to the synthesis of a full-fledged denitrification proteome. The model is based on the hypothesis that nirS has a low probability (, h−1) of initial transcription, but once initiated, the transcription is greatly enhanced through positive feedback by NO, resulting in the recruitment of the transcribing cell to denitrification. We assume that the recruitment is initiated as [O2] falls below a critical threshold and terminates (assuming energy-limitation) as [O2] exhausts. With  = 0.005 h−1, the model robustly simulates observed denitrification kinetics for a range of culture conditions. The resulting (fraction of the cells recruited to denitrification) falls within 0.038–0.161. In contrast, if the recruitment of the entire population is assumed, the simulated denitrification kinetics deviate grossly from those observed. The phenomenon can be understood as a ‘bet-hedging strategy’: switching to denitrification is a gain if anoxic spell lasts long but is a waste of energy if anoxia

  8. Multiple Mechanisms Contribute to the Cell Growth Defects Imparted by Human Telomerase Insertion in Fingers Domain Mutations Associated with Premature Aging Diseases.

    PubMed

    Chu, Tsz Wai; MacNeil, Deanna Elise; Autexier, Chantal

    2016-04-15

    Normal human stem cells rely on low levels of active telomerase to sustain their high replicative requirements. Deficiency in telomere maintenance mechanisms leads to the development of premature aging diseases, such as dyskeratosis congenita and aplastic anemia. Mutations in the unique "insertion in fingers domain" (IFD) in the human telomerase reverse transcriptase catalytic subunit (hTERT) have previously been identified and shown to be associated with dyskeratosis congenita and aplastic anemia. However, little is known about the molecular mechanisms impacted by these IFD mutations. We performed comparative functional analyses of disease-associated IFD variants at the molecular and cellular levels. We report that hTERT-P721R- and hTERT-R811C-expressing cells exhibited growth defects likely due to impaired TPP1-mediated recruitment of these variant enzymes to telomeres. We showed that activity and processivity of hTERT-T726M failed to be stimulated by TPP1-POT1 overexpression and that dGTP usage by this variant was less efficient compared with the wild-type enzyme. hTERT-P785L-expressing cells did not show growth defects, and this variant likely confers cell survival through increased DNA synthesis and robust activity stimulation by TPP1-POT1. Altogether, our data suggest that multiple mechanisms contribute to cell growth defects conferred by the IFD variants. PMID:26887940

  9. Characteristics of aerobic granulation at mesophilic temperatures in wastewater treatment.

    PubMed

    Cui, Fenghao; Park, Seyong; Kim, Moonil

    2014-01-01

    Compact and structurally stable aerobic granules were developed in a sequencing batch reactor (SBR) at mesophilic temperatures (35°C). The morphological, biological and chemical characteristics of the aerobic granulation were investigated and a theoretical granulation mechanism was proposed according to the results of the investigation. The mature aerobic granules had compact structure, small size (mean diameter of 0.24 mm), excellent settleability and diverse microbial structures, and were effective for the removal of organics and nitrification. The growth kinetics demonstrated that the biomass growth depended on coexistence and interactions between heterotrophs and autotrophs in the granules. The functions of heterotrophs and autotrophs created a compact and secure layer on the outside of the granules, protecting the inside sludge containing environmentally sensitive and slow growing microorganisms. The mechanism and the reactor performance may promise feasibility and efficiency for treating industry effluents at mesophilic temperatures using aerobic granulation. PMID:24211486

  10. Mitochondrial NAD Dependent Aldehyde Dehydrogenase either from Yeast or Human Replaces Yeast Cytoplasmic NADP Dependent Aldehyde Dehydrogenase for the Aerobic Growth of Yeast on Ethanol

    PubMed Central

    Mukhopadhyay, Abhijit; Wei, Baoxian; Weiner, Henry

    2013-01-01

    Background In a previous study, we deleted three aldehyde dehydrogenase (ALDH) genes, involved in ethanol metabolism, from yeast S. cerevisiae and found that the triple deleted yeast strain did not grow on ethanol as sole carbon source. The ALDHs were NADP dependent cytosolic ALDH1, NAD dependent mitochondrial ALDH2 and NAD/NADP dependent mitochondrial ALDH5. Double deleted strain ΔALDH2+ΔALDH5 or ΔALDH1+ΔALDH5 could grow on ethanol. However, the double deleted strain ΔALDH1+ΔALDH2 did not grow in ethanol. Methods Triple deleted yeast strain was used. Mitochondrial NAD dependent ALDH from yeast or human was placed in yeast cytosol. Results In the present study we found that a mutant form of cytoplasmic ALDH1 with very low activity barely supported the growth of the triple deleted strain (ΔALDH1+ΔALDH2+ΔALDH5) on ethanol. Finding the importance of NADP dependent ALDH1 on the growth of the strain on ethanol we examined if NAD dependent mitochondrial ALDH2 either from yeast or human would be able to support the growth of the triple deleted strain on ethanol if the mitochondrial form was placed in cytosol. We found that the NAD dependent mitochondrial ALDH2 from yeast or human was active in cytosol and supported the growth of the triple deleted strain on ethanol. Conclusion This study showed that coenzyme preference of ALDH is not critical in cytosol of yeast for the growth on ethanol. PMID:23454351

  11. Response of aerobic rice to Piriformospora indica.

    PubMed

    Das, Joy; Ramesh, K V; Maithri, U; Mutangana, D; Suresh, C K

    2014-03-01

    Rice cultivation under aerobic condition not only saves water but also opens up a splendid scope for effective application of beneficial root symbionts in rice crop unlike conventional puddled rice cultivation where water logged condition acts as constraint for easy proliferation of various beneficial soil microorganisms like arbuscular mycorrhizal (AM) fungi. Keeping these in view, an in silico investigation were carried out to explore the interaction of hydrogen phosphate with phosphate transporter protein (PTP) from P. indica. This was followed by greenhouse investigation to study the response of aerobic rice to Glomusfasciculatum, a conventional P biofertilizer and P. indica, an alternative to AM fungi. Computational studies using ClustalW tool revealed several conserved motifs between the phosphate transporters from Piriformospora indica and 8 other Glomus species. The 3D model of PTP from P. indica resembling "Mayan temple" was successfully docked onto hydrogen phosphate, indicating the affinity of this protein for inorganic phosphorus. Greenhouse studies revealed inoculation of aerobic rice either with P. indica, G. fasciculatum or both significantly enhanced the plant growth, biomass and yield with higher NPK, chlorophyll and sugar compared to uninoculated ones, P. indica inoculated plants being superior. A significantly enhanced activity of acid phosphatase and alkaline phosphatase were noticed in the rhizosphere soil of rice plants inoculated either with P. indica, G. fasciculatum or both, contributing to higher P uptake. Further, inoculation of aerobic rice plants with P. indica proved to be a better choice as a potential biofertilizer over mycorrhiza. PMID:24669667

  12. Anaerobic and aerobic transformation of TNT

    SciTech Connect

    Kulpa, C.F.; Boopathy, R.; Manning, J.

    1996-12-31

    Most studies on the microbial metabolism of nitroaromatic compounds have used pure cultures of aerobic microorganisms. In many cases, attempts to degrade nitroaromatics under aerobic conditions by pure cultures result in no mineralization and only superficial modifications of the structure. However, mixed culture systems properly operated result in the transformation of 2,4,6-trinitrotoluene (TNT) and in some cases mineralization of TNT occurs. In this paper, the mixed culture system is described with emphasis on intermediates and the characteristics of the aerobic microbial process including the necessity for a co-substrate. The possibility of removing TNT under aerobic/anoxic conditions is described in detail. Another option for the biodegradation of TNT and nitroaromatics is under anaerobic, sulfate reducing conditions. In this instance, the nitroaromatic compounds undergo a series of reductions with the formation of amino compounds. TNT under sulfate reducing conditions is reduced to triaminotoluene presumably by the enzyme nitrite reductase, which is commonly found in many Desulfovibrio spp. The removal of nitro groups from TNT is achieved by a series of reductive reactions with the formation of ammonia and toluene by Desulfovibrio sp. (B strain). These metabolic processes could be applied to other nitroaromatic compounds like nitrobenzene, nitrobenzoic acids, nitrophenols, and aniline. The data supporting the anaerobic transformation of TNT under different growth condition are reviewed in this report.

  13. Evaluation of skeletal tissue repair, part 1: assessment of novel growth-factor-releasing hydrogels in an ex vivo chick femur defect model.

    PubMed

    Smith, E L; Kanczler, J M; Gothard, D; Roberts, C A; Wells, J A; White, L J; Qutachi, O; Sawkins, M J; Peto, H; Rashidi, H; Rojo, L; Stevens, M M; El Haj, A J; Rose, F R A J; Shakesheff, K M; Oreffo, R O C

    2014-10-01

    Current clinical treatments for skeletal conditions resulting in large-scale bone loss include autograft or allograft, both of which have limited effectiveness. In seeking to address bone regeneration, several tissue engineering strategies have come to the fore, including the development of growth factor releasing technologies and appropriate animal models to evaluate repair. Ex vivo models represent a promising alternative to simple in vitro systems or complex, ethically challenging in vivo models. We have developed an ex vivo culture system of whole embryonic chick femora, adapted in this study as a critical size defect model to investigate the effects of novel bone extracellular matrix (bECM) hydrogel scaffolds containing spatio-temporal growth factor-releasing microparticles and skeletal stem cells on bone regeneration, to develop a viable alternative treatment for skeletal degeneration. Alginate/bECM hydrogels combined with poly (d,l-lactic-co-glycolic acid) (PDLLGA)/triblock copolymer (10-30% PDLLGA-PEG-PDLLGA) microparticles releasing VEGF, TGF-β3 or BMP-2 were placed, with human adult Stro-1+ bone marrow stromal cells, into 2mm central segmental defects in embryonic chick femurs. Alginate/bECM hydrogels loaded with HSA/VEGF or HSA/TGF-β3 demonstrated a cartilage-like phenotype, with minimal collagen I deposition, comparable to HSA-only control hydrogels. The addition of BMP-2 releasing microparticles resulted in enhanced structured bone matrix formation, evidenced by increased Sirius red-stained matrix and collagen expression within hydrogels. This study demonstrates delivery of bioactive growth factors from a novel alginate/bECM hydrogel to augment skeletal tissue formation and the use of an organotypic chick femur defect culture system as a high-throughput test model for scaffold/cell/growth factor therapies for regenerative medicine. PMID:24937137

  14. Analysis of defect structure in silicon. Silicon sheet growth development for the large area silicon sheet task of the Low-Cost Solar array Project

    NASA Technical Reports Server (NTRS)

    Natesh, R.; Mena, M.; Plichta, M.; Smith, J. M.; Sellani, M. A.

    1982-01-01

    One hundred ninety-three silicon sheet samples, approximately 880 square centimeters, were analyzed for twin boundary density, dislocation pit density, and grain boundary length. One hundred fifteen of these samples were manufactured by a heat exchanger method, thirty-eight by edge defined film fed growth, twenty-three by the silicon on ceramics process, and ten by the dendritic web process. Seven solar cells were also step-etched to determine the internal defect distribution on these samples. Procedures were developed or the quantitative characterization of structural defects such as dislocation pits, precipitates, twin & grain boundaries using a QTM 720 quantitative image analyzing system interfaced with a PDP 11/03 mini computer. Characterization of the grain boundary length per unit area for polycrystalline samples was done by using the intercept method on an Olympus HBM Microscope.

  15. The effect of AlN buffer growth parameters on the defect structure of GaN grown on sapphire by plasma-assisted molecular beam epitaxy

    NASA Astrophysics Data System (ADS)

    Wong, Yuen-Yee; Chang, Edward Yi; Yang, Tsung-Hsi; Chang, Jet-Rung; Chen, Yi-Cheng; Ku, Jui-Tai; Lee, Ching-Ting; Chang, Chun-Wei

    2009-03-01

    The defect structure of GaN film grown on sapphire by plasma-assisted molecular beam epitaxy (PAMBE) depends on the growth temperature and thickness of the aluminum nitride (AlN) buffer layer. High-resolution X-ray diffraction was used to measure symmetric (0 0 0 2) and asymmetric (1 0 1¯ 2) rocking curve (ω-scans) broadening, which allowed the estimation of screw threading dislocation (TD) and edge TD densities, respectively. For GaN grown on lower-temperature buffer, the density of screw TD was increased while the density of edge TD was decreased. Further examinations revealed that the edge TD was closely related to stress in GaN film and the screw TD was controlled by AlN surface roughness. Since the GaN defect was dominated by edge TD, the total TD was also effectively suppressed with the use of lower-temperature buffer with appropriate thickness.

  16. Aerobic secondary utilization of a non-growth and inhibitory substrate 2,4,6-trichlorophenol by Sphingopyxis chilensis S37 and sphingopyxis-like strain S32.

    PubMed

    Aranda, Carlos; Godoy, Félix; Becerra, José; Barra, Ricardo; Martínez, Miguel

    2003-08-01

    This paper reports 2,4,6-trichlorophenol (246TCP) degradation by Sphingopyxis chilensis S37 and Sphingopyxis chilensis-like strain S32, which were unable to use 246TCP as the sole carbon and energy source. In R2A broth, the strains degraded 246TCP up to 0.5 mM. Results with mixtures of different 246TCP and glucose concentrations in mineral salt media demonstrated dependence on glucose to allow bacterial growth and degradation of 246TCP. Strain S32 degraded halophenol up to 0.2 mM when 5.33 mM glucose was simultaneously added, while strain S37 degraded the compound up to 0.1 mM when 1.33 mM glucose was added. These 246TCP concentrations were lethal for inocula in absence of glucose. Stoichiometric releases of chloride and analysis by HPLC, GC-ECD and GC-MS indicated 246TCP mineralisation by both strains. To our knowledge, this is the first report of bacteria able to mineralize a chlorophenol as a non-growth and inhibitory substrate. The concept of secondary utilization instead of cometabolism is proposed for this activity. PMID:12948056

  17. Selective area growth of InP in shallow trench isolation on large scale Si(001) wafer using defect confinement technique

    NASA Astrophysics Data System (ADS)

    Merckling, C.; Waldron, N.; Jiang, S.; Guo, W.; Richard, O.; Douhard, B.; Moussa, A.; Vanhaeren, D.; Bender, H.; Collaert, N.; Heyns, M.; Thean, A.; Caymax, M.; Vandervorst, W.

    2013-07-01

    Heterogeneous integration of III-V semiconductors on Si substrate has been attracting much attention as building blocks for next-generation electronics, optoelectronics, and photonics. In the present paper, we studied the selective area epitaxial studies of InP grown on 300 mm on-axis Si (001) substrates patterned with Shallow Trench Isolation (STI) using the necking effect technique to trap crystalline defects on the sidewalls. We make use of a thin Ge buffer in the bottom of the trench to reduce interfacial strain at the interface and to promote InP nucleation. We could show here, by systematic analysis, the strong impact of the growth temperatures and pressures of the InP layer on the growth uniformity along the trench and crystalline quality that we correlated with resistance changes and interdiffusion measured in the III-V layer. The key challenge remains in the ultimate control of crystalline quality during InP selective growth in order to reduce defect density to enable device-quality III-V virtual substrates on large-scale Si substrates.

  18. Aerobic landfill bioreactor

    DOEpatents

    Hudgins, Mark P; Bessette, Bernard J; March, John C; McComb, Scott T.

    2002-01-01

    The present invention includes a system of decomposing municipal solid waste (MSW) within a landfill by converting the landfill to aerobic degradation in the following manner: (1) injecting air via the landfill leachate collection system (2) injecting air via vertical air injection wells installed within the waste mass; (3) applying leachate to the waste mass using a pressurized drip irrigation system; (4) allowing landfill gases to vent; and (5) adjusting air injection and recirculated leachate to achieve a 40% to 60% moisture level and a temperature between 120.degree. F. and 140.degree. F. in steady state.

  19. Aerobic landfill bioreactor

    DOEpatents

    Hudgins, Mark P; Bessette, Bernard J; March, John; McComb, Scott T.

    2000-01-01

    The present invention includes a method of decomposing municipal solid waste (MSW) within a landfill by converting the landfill to aerobic degradation in the following manner: (1) injecting air via the landfill leachate collection system (2) injecting air via vertical air injection wells installed within the waste mass; (3) applying leachate to the waste mass using a pressurized drip irrigation system; (4) allowing landfill gases to vent; and (5) adjusting air injection and recirculated leachate to achieve a 40% to 60% moisture level and a temperature between 120.degree. F. and 140.degree. F. in steady state.

  20. Aerobic microbial mineralization of dichloroethene as sole carbon substrate

    USGS Publications Warehouse

    Bradley, P.M.; Chapelle, F.H.

    2000-01-01

    Microorganisms indigenous to the bed sediments of a black- water stream utilized 1,2-dichloroethene (1,2-DCE) as a sole carbon substrate for aerobic metabolism. Although no evidence of growth was observed in the minimal salts culture media used in this study, efficient aerobic microbial mineralization of 1,2-DCE as sole carbon substrate was maintained through three sequential transfers (107 final dilution) of the original environmental innoculum. These results indicate that 1,2-DCE can be utilized as a primary substrate to support microbial metabolism under aerobic conditions.Microorganisms indigenous to the bed sediments of a black-water stream utilized 1,2-dichloroethene (1,2-DCE) as a sole carbon substrate for aerobic metabolism. Although no evidence of growth was observed in the minimal salts culture media used in this study, efficient aerobic microbial mineralization of 1,2-DCE as sole carbon substrate was maintained through three sequential transfers (107 final dilution) of the original environmental innoculum. These results indicate that 1,2-DCE can be utilized as a primary substrate to support microbial metabolism under aerobic conditions.

  1. Birth Defects

    MedlinePlus

    ... NICHD Research Information Clinical Trials Resources and Publications Birth Defects: Condition Information Skip sharing on social media links Share this: Page Content What are birth defects? Birth defects are structural or functional abnormalities present ...

  2. Programmed Application of Transforming Growth Factor β3 and Rac1 Inhibitor NSC23766 Committed Hyaline Cartilage Differentiation of Adipose-Derived Stem Cells for Osteochondral Defect Repair

    PubMed Central

    Zhu, Shouan; Chen, Pengfei; Wu, Yan; Xiong, Si; Sun, Heng; Xia, Qingqing; Shi, Libing

    2014-01-01

    Hyaline cartilage differentiation is always the challenge with application of stem cells for joint repair. Transforming growth factors (TGFs) and bone morphogenetic proteins can initiate cartilage differentiation but often lead to hypertrophy and calcification, related to abnormal Rac1 activity. In this study, we developed a strategy of programmed application of TGFβ3 and Rac1 inhibitor NSC23766 to commit the hyaline cartilage differentiation of adipose-derived stem cells (ADSCs) for joint cartilage repair. ADSCs were isolated and cultured in a micromass and pellet culture model to evaluate chondrogenic and hypertrophic differentiation. The function of Rac1 was investigated with constitutively active Rac1 mutant and dominant negative Rac1 mutant. The efficacy of ADSCs with programmed application of TGFβ3 and Rac1 inhibitor for cartilage repair was studied in a rat model of osteochondral defects. The results showed that TGFβ3 promoted ADSCs chondro-lineage differentiation and that NSC23766 prevented ADSC-derived chondrocytes from hypertrophy in vitro. The combination of ADSCs, TGFβ3, and NSC23766 promoted quality osteochondral defect repair in rats with much less chondrocytes hypertrophy and significantly higher International Cartilage Repair Society macroscopic and microscopic scores. The findings have illustrated that programmed application of TGFβ3 and Rac1 inhibitor NSC23766 can commit ADSCs to chondro-lineage differentiation and improve the efficacy of ADSCs for cartilage defect repair. These findings suggest a promising stem cell-based strategy for articular cartilage repair. PMID:25154784

  3. Bone resorption analysis of platelet-derived growth factor type BB application on collagen for bone grafts secured by titanium mesh over a pig jaw defect model

    PubMed Central

    Herford, Alan Scott; Cicciù, Marco

    2012-01-01

    Purpose: The aim of this investigation was to evaluate whether the addition of the platelet derived growth factor type BB (PDGF-BB) to a collagen matrix applied on a titanium mesh would favor healing and resorption onto the grafted bone. A histologic and radiographic study of two different groups (test and control) was performed. Designs: A surgical procedure was performed on 8 pigs to obtain 16 bilateral mandibular alveolar defects. All the defects were then reconstructed with a mixture of autogenous bovine bone using titanium mesh positioning. Two groups, with a total of 16 defects were created: The first to study collagen sponge and PDGF-BB and the second to control collagen only. The collagen matrix was positioned directly over the mesh and soft tissue was closed without tensions onto both groups without attempting to obtain primary closure. Possible exposure of the titanium mesh as well as the height and volume of the new bone was recorded. Results: New bone formation averaged about 6.68 mm in the test group studied; the control group had less regenerated bone at 4.62 mm. Conclusion: PDGF-BB addition to the collagen matrix induced a strong increase in hard and soft tissue healing and favored bone formation, reducing bone resorption even if the mesh was exposed. PMID:23833493

  4. A single major-gene defect underlying cardiac conotruncal malformations interferes with myocardial growth during embryonic development: studies in the CTD line of keeshond dogs.

    PubMed Central

    Patterson, D F; Pexieder, T; Schnarr, W R; Navratil, T; Alaili, R

    1993-01-01

    The common forms of isolated congenital heart disease are usually not inherited in a Mendelian pattern, and most are considered multifactorial threshold traits. A large subset consisting of a group of malformations of the ventricular outflow region, termed "conotruncal defects" (CTDs), include subarterial ventricular septal defects, tetralogy of Fallot, and persistent truncus arteriosus. Similar aggregations of CTDs have been reported in human families and in the keeshond breed of dog. The results of our early breeding experiments utilizing noninbred keeshonds were not consistent with any hypothesis of a fully penetrant monogenic inheritance. Here we report a recent series of genetic and embryologic studies conducted after more than 10 generations of selective inbred matings between affected-CTD-line dogs. The results are now consistent with a defect at a single autosomal locus, the Mendelian pattern of transmission having been obscured prior to selective inbreeding by genetic background. On the basis of morphometric embryologic studies, the mutant CTD allele causes conotruncal malformations in homozygous animals by interfering with myocardial growth in the conotruncus during the critical window when the conotruncal cushions fuse to form the conotruncal septum. PMID:8430699

  5. Characterization of crack growth resistance under cyclic loading in the presence of an unbridged defect in fiber-reinforced titanium metal matrix composites

    SciTech Connect

    Bowen, P.

    1996-12-31

    This paper considers the experimental characterization of crack growth from unbridged defects in fiber-reinforced titanium metal matrix composites subjected to cyclic loading by the use of fracture mechanics parameters. The conditions under which parameters such as the nominal applied stress intensity range, {Delta}K{sub app}, the nominal maximum stress intensity factor, K{sub max}, and the effective stress intensity range, {Delta}K{sub eff}, are of use, and their experimental measurements are considered. Effects of fiber fracture, stress intensity factor range, mean stress, loading configuration (bending versus tension), test temperature, crack size, crack shape, and fiber-matrix interfacial strength on fatigue crack growth resistance are highlighted. The experimental determination of crack arrest in such composites is outlined.

  6. Ethanol-induced impairment of polyamine homeostasis – A potential cause of neural tube defect and intrauterine growth restriction in fetal alcohol syndrome

    SciTech Connect

    Haghighi Poodeh, Saeid; Alhonen, Leena; Salonurmi, Tuire; Savolainen, Markku J.

    2014-03-28

    Highlights: • Polyamine pools in embryonic and extraembryonic tissues are developmentally regulated. • Alcohol administration perturbs polyamine levels in the tissues with various patterns. • Total absence of polyamines in the embryo head at 9.5 dpc is critical for development. • The deficiency is associated with reduction in endothelial cell sprouting in the head. • Retarded migration of neural crest cells may cause development of neural tube defect. - Abstract: Introduction: Polyamines play a fundamental role during embryogenesis by regulating cell growth and proliferation and by interacting with RNA, DNA and protein. The polyamine pools are regulated by metabolism and uptake from exogenous sources. The use of certain inhibitors of polyamine synthesis causes similar defects to those seen in alcohol exposure e.g. retarded embryo growth and endothelial cell sprouting. Methods: CD-1 mice received two intraperitoneal injections of 3 g/kg ethanol at 4 h intervals 8.75 days post coitum (dpc). The fetal head, trunk, yolk sac and placenta were collected at 9.5 and 12.5 dpc and polyamine concentrations were determined. Results: No measurable quantity of polyamines could be detected in the embryo head at 9.5 dpc, 12 h after ethanol exposure. Putrescine was not detectable in the trunk of the embryo at that time, whereas polyamines in yolk sac and placenta were at control level. Polyamine deficiency was associated with slow cell growth, reduction in endothelial cell sprouting, an altered pattern of blood vessel network formation and consequently retarded migration of neural crest cells and growth restriction. Discussion: Our results indicate that the polyamine pools in embryonic and extraembryonic tissues are developmentally regulated. Alcohol administration, at the critical stage, perturbs polyamine levels with various patterns, depending on the tissue and its developmental stage. The total absence of polyamines in the embryo head at 9.5 dpc may explain why this

  7. Aerobic Fitness and School Children.

    ERIC Educational Resources Information Center

    Hinkle, J. Scott

    1997-01-01

    Provides school counselors with information on aerobic exercise (specifically running) and the psychological, behavioral, and physical benefits children obtained by participating in fitness programs. Recommends collaboration between school counselors and physical education teachers and gives a preliminary discussion of aerobic running and its…

  8. Aerobic Fitness and School Children.

    ERIC Educational Resources Information Center

    Hinkle, J. Scott

    1992-01-01

    Provides school counselors with information regarding aerobic exercise (specifically running), and the psychological, behavioral, and physical benefits children obtain by participating in fitness programs. Presents methods of collaboration between school counselors and physical education teachers. Offers preliminary discussion of aerobic running…

  9. Exercise, Animal Aerobics, and Interpretation?

    ERIC Educational Resources Information Center

    Oliver, Valerie

    1996-01-01

    Describes an aerobic activity set to music for children that mimics animal movements. Example exercises include walking like a penguin or jumping like a cricket. Stresses basic aerobic principles and designing the program at the level of children's motor skills. Benefits include reaching people who normally don't visit nature centers, and bridging…

  10. Birth Defects

    MedlinePlus

    A birth defect is a problem that happens while a baby is developing in the mother's body. Most birth defects happen during the first 3 months of ... in the United States is born with a birth defect. A birth defect may affect how the ...

  11. Effect of defects in oxide templates on Non-catalytic growth of GaN nanowires for high-efficiency light-emitting diodes

    NASA Astrophysics Data System (ADS)

    Hwang, Sung Won; Choi, Suk-Ho

    2016-04-01

    Two kinds of oxide templates, one with and one without undercuts, are employed to study the effect of defects in oxide templates on non-catalytic growth of GaN nanowires (NWs). GaN NWs abnormally grown from the templates containing undercuts exhibit two types of patterns: earlystage growth of premature NWs and abnormally-overgrown (~2 μm) NWs. GaN NWs grown on perfectly-symmetric template patterns are highly crystalline and have high aspect ratios (2 ~ 5), and their tops are shaped as pyramids with semipolar facets, clearly indicating hexagonal symmetry. The internal quantum efficiency of the well-grown NWs is 10% larger than that of the deformed NWs, as estimated by using photoluminescence. These results suggest that our technique is an effective approach for growing large-area-patterned, vertically-aligned, hexagonal GaN NWs without catalysts, in strong contrast to catalytic vapor-liquid-solid growth, and that good formation of the oxide templates is crucial for the growth of high-quality GaN NWs.

  12. [Heterotrophic Nitrification and Aerobic Denitrification of the Hypothermia Aerobic Denitrification Bacterium: Arthrobacter arilaitensis].

    PubMed

    He, Teng-xia; Ni, Jiu-pai; Li, Zhen-lun; Sun, Quan; Ye Qing; Xu, Yi

    2016-03-15

    High concentrations of ammonium, nitrate and nitrite nitrogen were employed to clarify the abilities of heterotrophic nitrification and aerobic denitrification of Arthrobacter arilaitensis strain Y-10. Meanwhile, by means of inoculating the strain suspension into the mixed ammonium and nitrate, ammonium and nitrite nitrogen simulated wastewater, we studied the simultaneous nitrification and denitrification ability of Arthrobacter arilaitensis strain Y-10. In addition, cell optical density was assayed in each nitrogen removal process to analyze the relationship of cell growth and nitrogen removal efficiency. The results showed that the hypothermia denitrification strain Arthrobacter arilaitensis Y-10 exhibited high nitrogen removal efficiency during heterotrophic nitrification and aerobic denitrification. The ammonium, nitrate and nitrite removal rates were 65.0%, 100% and 61.2% respectively when strain Y-10 was cultivated for 4 d at 15°C with initial ammonium, nitrate and nitrite nitrogen concentrations of 208.43 mg · L⁻¹, 201.16 mg · L⁻¹ and 194.33 mg · L⁻¹ and initial pH of 7.2. Nitrite nitrogen could only be accumulated in the medium containing nitrate nitrogen during heterotrophic nitrification and aerobic denitrification process. Additionally, the ammonium nitrogen was mainly removed in the inorganic nitrogen mixed synthetic wastewater. In short, Arthrobacter arilaitensis Y-10 could conduct nitrification and denitrification effectively under aerobic condition and the ammonium nitrogen removal rate was more than 80.0% in the inorganic nitrogen mixed synthetic wastewater. PMID:27337904

  13. Tissue segregation restores the induction of bone formation by the mammalian transforming growth factor-β(3) in calvarial defects of the non-human primate Papio ursinus.

    PubMed

    Ripamonti, U; Klar, Roland Manfred; Parak, Ruqayya; Dickens, Caroline; Dix-Peek, Therese; Duarte, Raquel

    2016-04-01

    A diffusion molecular hypothesis from the dura and/or the leptomeninges below that would control the induction of calvarial membranous bone formation by the recombinant human transforming growth factor-β3 (hTGF-β3) was investigated. Coral-derived calcium carbonate-based macroporous constructs (25 mm diameter; 3.5/4 mm thickness) with limited hydrothermal conversion to hydroxyapatite (7% HA/CC) were inserted into forty calvarial defects created in 10 adult Chacma baboons Papio ursinus. In 20 defects, an impermeable nylon foil membrane (SupraFOIL(®)) was inserted between the cut endocranial bone and the underlying dura mater. Twenty of the macroporous constructs were preloaded with hTGF-β3 (125 μg in 1000 μl 20 mM sodium succinate, 4% mannitol pH4.0), 10 of which were implanted into defects segregated by the SupraFOIL(®) membrane, and 10 into non-segregated defects. Tissues were harvested on day 90, processed for decalcified and undecalcified histology and quantitative real-time polymerase chain reaction (qRT-PCR). Segregated untreated macroporous specimens showed a reduction of bone formation across the macroporous spaces compared to non-segregated constructs. qRT-PCR of segregated untreated specimens showed down regulation of osteogenic protein-1 (OP-1), osteocalcin (OC), bone morphogenetic protein-2 (BMP-2), RUNX-2 and inhibitor of DNA binding-2 and -3 (ID2,ID3) and up regulation of TGF-β3, a molecular signalling pathway inhibiting the induction of membranous bone formation. Non-segregated hTGF-β3/treated constructs also showed non-osteogenic expression profiles when compared to non-segregated untreated specimens. Segregated hTGF-β3/treated 7% HA/CC constructs showed significantly greater induction of bone formation across the macroporous spaces and, compared to non-segregated hTGF-β3/treated constructs, showed up regulation of OP-1, OC, BMP-2, RUNX-2, ID2 and ID3. Similar up-regulated expression profiles were seen for untreated non

  14. Aerobic and anaerobic cellulase production by Cellulomonas uda.

    PubMed

    Poulsen, Henrik Vestergaard; Willink, Fillip Wolfgang; Ingvorsen, Kjeld

    2016-10-01

    Cellulomonas uda (DSM 20108/ATCC 21399) is one of the few described cellulolytic facultative anaerobes. Based on these characteristics, we initiated a physiological study of C. uda with the aim to exploit it for cellulase production in simple bioreactors with no or sporadic aeration. Growth, cellulase activity and fermentation product formation were evaluated in different media under both aerobic and anaerobic conditions and in experiments where C. uda was exposed to alternating aerobic/anaerobic growth conditions. Here we show that C. uda behaves as a true facultative anaerobe when cultivated on soluble substrates such as glucose and cellobiose, but for reasons unknown cellulase activity is only induced under aerobic conditions on insoluble cellulosic substrates and not under anaerobic conditions. These findings enhance knowledge on the limited number of described facultative cellulolytic anaerobes, and in addition it greatly limits the utility of C. uda as an 'easy to handle' cellulase producer with low aeration demands. PMID:27154570

  15. Characterization of aerobic ethanol productions in a computerized auxostat

    SciTech Connect

    Fraleigh, S.P.

    1989-01-01

    For many valuable bioproducts high productivity is associated with rapid growth. However, most continuous microbial cultures become unstable when the dilution rate is fixed near the value for maximum growth rate. The auxostat culture technique employs feedback control of a nutrient or metabolite to stabilize the biomass at its maximum potential growth rate. An auxostat device is therefore ideal for study of bioprocesses involving the overproduction of primary metabolites such as ethanol. Oxidoreductive transformations involving ethanol are utilized by Saccharomyces yeasts when normal respiration cannot satisfy energy needs. When rapid growth or other stress creates oxidoreductive conditions in aerobic Saccharomyces cultures, very high specific ethanol formation rates are established and biomass yield drops to levels more typical of anaerobic fermentation. Although the physiology is favorable, the potential for large-scale aerobic ethanol processes to compete with traditional anaerobic fermentations has not previously been assessed. In this study, a fully computerized auxostat device was constructed and used to characterize the specific and volumetric aerobic ethanol productivity of the yeast Saccharomyces cerevisiae. To divert substrate away from biomass and into product formation, aerobic cultures were stressed with variations of ionic balance (via extreme K{sup +} and H{sup +} setpoints) in the auxostat device. During growth with limiting K{sup +} concentrations, the goal of very low biomass yield was attained but the rate of ethanol production was poor. However, with excess K{sup +} the volumetric productivity reached 6.1 g/I,-h, a value that is comparable to optimized, continuous anaerobic cultures.

  16. Generalized disruption of inherited genomic imprints leads to wide-ranging placental defects and dysregulated fetal growth

    PubMed Central

    Himes, K. P.; Koppes, E.; Chaillet, J. Richard

    2012-01-01

    Monoallelic expression of imprinted genes, including ones solely expressed in the placenta, is essential for normal placental development and fetal growth. To better understand the role of placental imprinting in placental development and fetal growth, we examined conceptuses developing in the absence of maternally derived DNA (cytosine-5-)- methyltransferase 1o (DNMT1o). Absence of DNMT1o results in the partial loss of methylation at imprinted differentially methylated domain (DMD) sequences in the embryo and the placenta. Mid-gestation E9.5 DNMT1o-deficient placentas exhibited structural abnormalities of all tissue layers. At E17.5, all examined placentas had aberrant placental morphology, most notably in the spongiotrophoblast and labyrinth layers. Abnormalities included an expanded volume fraction of spongiotrophoblast tissue with extension of the spongiotrophoblast layer into the labyrinth. Many mutant placentas also demonstrated migration abnormalities of glycogen cells. Additionally, the volume fraction of the labyrinth was reduced, as was the surface area for maternal fetal gas exchange. Despite these placental morphologic abnormalities, approximately one-half of DNMT1o-deficient fetuses survived to late gestation (E17.5). Furthermore, DNMT1o- deficient placentas supported a broad range of fetal growth. The ability of some DNMT1o-deficient and morphologically abnormal placentas to support fetal growth in excess of wild type demonstrates the importance of differential methylation of DMDs and proper imprinting of discrete gene clusters to placental morphogenesis and fetal growth. PMID:23085235

  17. The Effect of the Wall Contact and Post-Growth C001-Down on Defects in CdTe Crystals Grown by Contactless PVT

    NASA Technical Reports Server (NTRS)

    Palosz, W.; Grasza, K.; Dudley, M.; Raghothamachar, B.; Cai, L.; Durose, K.; Halliday, D.; Boyall, N. M.; Rose, M. Franklin (Technical Monitor)

    2001-01-01

    In crystal growth, the quality of the final material may depend, among other factors, on its interaction with the walls of the ampoule during and after the growth, and on the rate of the crystal cool-down at the end of ate the process. To investigate the above phenomena, a series of CdTe crystal growth processes was carried out, The crystals were grown by physical vapor transport without contact with the side walls of the silica glass ampoules, applying the Low Supersaturation Nucleation technique. The source temperature was 930 C, the undercooling was a few degrees. The crystals, having the diameter of 25 mm, grew at the rate of a few mm per day. The post-growth cool-down to the room temperature was conducted at different rates, and lasted from a few minutes to four days. The crystals were characterized using chemical etching low temperature luminescence, and Synchrotron White Beam X-ray Topography techniques. The dislocation (etch pit) density was measured and its distribution was analyzed by comparison with Poisson curves and with the Normalized Radial Distribution Correlation Function. It was found that the contact of the crystal with silica leads to a strain field and high (in the 105 sq cm range) dislocation (etch pit) density. Similar defect concentrations were found in crystals subjected to fast post-growth cool-down. Typical EPD values for lower cool-down rates and in regions not affected by wall interactions are in the lower 10(exp 4) sq cm range. In some areas the actual dislocation density was about 10(exp 3) sq cm or even less. No apparent effect of the cool-down rate on polygonization was observed. A fine structure could be discerned in low-temperature PL spectra of crystals with low dislocation density.

  18. Aerobic Microbial Degradation of Glucoisosaccharinic Acid

    PubMed Central

    Strand, S. E.; Dykes, J.; Chiang, V.

    1984-01-01

    α-Glucoisosaccharinic acid (GISA), a major by-product of kraft paper manufacture, was synthesized from lactose and used as the carbon source for microbial media. Ten strains of aerobic bacteria capable of growth on GISA were isolated from kraft pulp mill environments. The highest growth yields were obtained with Ancylobacter spp. at pH 7.2 to 9.5. GISA was completely degraded by cultures of an Ancylobacter isolate. Ancylobacter cell suspensions consumed oxygen and produced carbon dioxide in response to GISA addition. A total of 22 laboratory strains of bacteria were tested, and none was capable of growth on GISA. GISA-degrading isolates were not found in forest soils. Images PMID:16346467

  19. Reduction of ectopic bone growth in critically-sized rat mandible defects by delivery of rhBMP-2 from kerateine biomaterials

    PubMed Central

    Kowalczewski, Christine J.; Tombyln, Seth; Wasnick, David C.; Hughes, Michael R.; Ellenburg, Mary D.; Callahan, Michael F.; Smith, Thomas L.; Van Dyke, Mark E.; Burnett, Luke R.; Saul, Justin M.

    2014-01-01

    Absorbable collagen sponges (ACS) are used clinically as carriers of recombinant human bone morphogenetic protein 2 (rhBMP-2) to promote bone regeneration. ACS exhibit ectopic bone growth due to delivery of supraphysiological levels of rhBMP-2, which is particularly problematic in craniofacial bone injuries for both functional and esthetic reasons. We hypothesized that hydrogels from the reduced form of keratin proteins (kerateine) would serve as a suitable alternative to ACS carriers of rhBMP-2. The rationale for this hypothesis is that keratin biomaterials degrade slowly in vivo, have modifiable material properties, and have demonstrated capacity to deliver therapeutic agents. We investigated kerateine hydrogels and freeze-dried scaffolds as rhBMP-2 carriers in a critically-sized rat mandibular defect model. ACS, kerateine hydrogels, and kerateine scaffolds loaded with rhBMP-2 achieved bridging in animals by 8 weeks as indicated by micro-computed tomography. Kerateine scaffolds achieved statistically increased bone mineral density compared to ACS and kerateine hydrogels, with levels reaching those of native bone. Importantly, both kerateine hydrogels and kerateine scaffolds had significantly less ectopic bone growth than ACS sponges at both 8 and 16 weeks post-operatively. These studies demonstrate the suitability of keratins as rhBMP-2 carriers due to equal regenerative capacity with reduced ectopic growth compared to ACS. PMID:24439399

  20. Improvement of the healing of a rat tibia defect by means of a Calcium Carbonate based biopolymer mixed with Epidermal Growth Factor and Ascorbic Acid

    NASA Astrophysics Data System (ADS)

    Mendoza-Barrera, C.; Meléndez-Lira, M.; Hernández-Flores, C.; Lecona-Butrón, H.; García-López, E. S.

    2000-10-01

    At the present bone reparation is commonly solved by means of different graft types. Biomaterials such as hidroxyapatite, coraline, octacalcium phosphate and tricalcium phosphate are used. By other side there are factors like Epidermal Growth Factor (EGF), Fibroblast Growth Factor (TGF), Laminine, Ascorbic Acid (AA), etc. that stimulate the osteogenesis in fracture or bony defect. The goal of this work is to evaluate the effect of the addition of EGF and ascorbic acid to a Ca2CO3 based biopolymer in the healing of a rat tibia model to improve the consolidation with adequate bony quality. No implant rejection or inflammatory reaction was observed during a 5 weeks period in our in vivo studies. The evolution of the osteointegration has been followed employing scanning electronic microscopy (SEM), energy dispersive x-ray analysis (EDX), and biochemistry activity for calcium, phosphor and alkaline phosphatase. We conclude that the combined use of the based Ca2CO3 biopolymer with Ascorbic Acid and Epidermal Growth Factor (group B&AA&EGF) in vivo accelerates the process of bony repair, as compared with the other groups. The mixture B&AA&EGF provide a bridge in the lesion, helping in the cellular migration and increasing the collagen synthesis.

  1. Standard YPD, even supplemented with extra nutrients, does not always compensate growth defects of Saccharomyces cerevisiae auxotrophic strains.

    PubMed

    Corbacho, Isaac; Teixidó, Francisco; Velázquez, Rocío; Hernández, Luis M; Olivero, Isabel

    2011-03-01

    Conventional complex media are routinely used to grow auxotrophic strains under the assumption that they can compensate the latter's nutritional deficiencies. We here demonstrate that this is not always true. This study compares the growth parameters of Saccharomyces cerevisiae (S288C) and its derived auxotrophic strains FY1679-14C and BY4741 in synthetic minimal medium (SD), standard YPD medium from two of the most commonly used suppliers, or modified YPD medium. Maximum specific growth rates of auxotrophic strains were slightly lower than the prototrophic case in all growth conditions tested. Also, the biomass production of auxotrophic strains in synthetic medium was slightly less than the prototrophic case. However in both of the two standard YPD media used, the biomass production of both auxotrophic strains was markedly lower than that of the prototrophic one. The extent of the differences depended on the medium used. Indeed in one of the two YPD media, the lower biomass production of auxotrophic strains was evident even at the diauxic shift. Uracil seems to be the main limiting growth factor for both auxotrophic strains growing in the two standard YPD medium tested. No YPD media or specific supplement was able to compensate for the effect of the auxotrophic mutations in the multiple auxotrophic marker strain BY4741. The fact that auxotrophic strains grew poorly on YPD when compared to their prototrophic counterpart indicates that standard YPD medium is not sufficient to overcome the effect of auxotrophic mutations. PMID:21120607

  2. Defect in insulin-like growth factor-1 survival mechanism in atherosclerotic plaque-derived vascular smooth muscle cells is mediated by reduced surface binding and signaling.

    PubMed

    Patel, V A; Zhang, Q J; Siddle, K; Soos, M A; Goddard, M; Weissberg, P L; Bennett, M R

    2001-05-11

    Apoptosis of vascular smooth muscle cells (VSMCs) is increased in atherosclerosis compared with normal vessels, where it may contribute to plaque rupture. We have previously found that human plaque-derived VSMCs (pVSMCs) are intrinsically sensitive to apoptosis and not responsive to the protective effects of insulin-like growth factor-1 (IGF-1). We therefore examined the mechanism underlying this defect. Human pVSMCs showed <25% (125)I-IGF-1 surface binding, <20% IGF-1 receptor (IGF-1R) expression than that of normal medial VSMCs, and <40% Akt kinase activity in response to IGF-1. pVSMCs expressed and secreted high levels of IGF-1 binding proteins (IGFBPs), and the IGF-1 analogues, long R3 and Des 1,3 IGF-1, which do not bind to IGFBPs, were able to increase pVSMC survival to normal medial VSMC levels. The long R3 survival effect was phosphatidylinositol 3-kinase-mediated, but it was not dependent on Akt activity alone. Intimal pVSMCs in vivo showed reduced IGF-1R expression compared with medial VSMCs, in particular at the shoulder regions of plaques. We conclude that human pVSMCs show an intrinsic sensitivity to apoptosis caused in part by defective expression of IGF-1R, impaired IGF-1-mediated survival signaling and increased IGFBP secretion. This impaired IGF-1 protection against apoptosis may promote VSMC loss and plaque instability in atherosclerosis. PMID:11348998

  3. Metabolomics Revealed an Association of Metabolite Changes and Defective Growth in Methylobacterium extorquens AM1 Overexpressing ecm during Growth on Methanol

    PubMed Central

    Hu, Bo; Yang, Jing; Wang, Qianwen; Sadilek, Martin; Yang, Song

    2016-01-01

    Methylobacterium extorquens AM1 is a facultative methylotroph capable of growth on both single-carbon and multi-carbon compounds. The ethylmalonyl-CoA (EMC) pathway is one of the central assimilatory pathways in M. extorquens during growth on C1 and C2 substrates. Previous studies had shown that ethylmalonyl-CoA mutase functioned as a control point during the transition from growth on succinate to growth on ethylamine. In this study we overexpressed ecm, phaA, mcmAB and found that upregulating ecm by expressing it from the strong constitutive mxaF promoter caused a 27% decrease in growth rate on methanol compared to the strain with an empty vector. Targeted metabolomics demonstrated that most of the central intermediates in the ecm over-expressing strain did not change significantly compared to the control strain; However, poly-β-hydroxybutyrate (PHB) was 4.5-fold lower and 3-hydroxybutyryl-CoA was 1.6-fold higher. Moreover, glyoxylate, a toxic and highly regulated essential intermediate, was determined to be 2.6-fold higher when ecm was overexpressed. These results demonstrated that overexpressing ecm can manipulate carbon flux through the EMC pathway and divert it from the carbon and energy storage product PHB, leading to an accumulation of glyoxylate. Furthermore, untargeted metabolomics discovered two unusual metabolites, alanine (Ala)–meso-diaminopimelic acid (mDAP) and Ala–mDAP–Ala, each over 45-fold higher in the ecm over-expressing strain. These two peptides were also found to be highly produced in a dose-dependent manner when glyoxylate was added to the control strain. Overall, this work has explained a direct association of ecm overexpression with glyoxylate accumulation up to a toxic level, which inhibits cell growth on methanol. This research provides useful insight for manipulating the EMC pathway for efficiently producing high-value chemicals in M. extorquens. PMID:27116459

  4. Metabolomics revealed an association of metabolite changes and defective growth in Methylobacterium extorquens AM1 overexpressing ecm during growth on methanol

    DOE PAGESBeta

    Cui, Jinyu; Good, Nathan M.; Hu, Bo; Yang, Jing; Wang, Qianwen; Sadilek, Martin; Yang, Song; Berg, Ivan A.

    2016-04-26

    Methylobacterium extorquens AM1 is a facultative methylotroph capable of growth on both single-carbon and multi-carbon compounds. The ethylmalonyl-CoA (EMC) pathway is one of the central assimilatory pathways in M. extorquens during growth on C1 and C2 substrates. Previous studies had shown that ethylmalonyl-CoA mutase functioned as a control point during the transition from growth on succinate to growth on ethylamine. In this study we overexpressed ecm, phaA, mcmAB and found that upregulating ecm by expressing it from the strong constitutive mxaF promoter caused a 27% decrease in growth rate on methanol compared to the strain with an empty vector. Targetedmore » metabolomics demonstrated that most of the central intermediates in the ecm over-expressing strain did not change significantly compared to the control strain; However, poly-β-hydroxybutyrate (PHB) was 4.5-fold lower and 3-hydroxybutyryl-CoA was 1.6-fold higher. Moreover, glyoxylate, a toxic and highly regulated essential intermediate, was determined to be 2.6-fold higher when ecm was overexpressed. These results demonstrated that overexpressing ecm can manipulate carbon flux through the EMC pathway and divert it from the carbon and energy storage product PHB, leading to an accumulation of glyoxylate. Furthermore, untargeted metabolomics discovered two unusual metabolites, alanine (Ala)-meso-diaminopimelic acid (mDAP) and Ala-mDAP-Ala, each over 45-fold higher in the ecm overexpressing strain. These two peptides were also found to be highly produced in a dose-dependent manner when glyoxylate was added to the control strain. Overall, this work has explained a direct association of ecm overexpression with glyoxylate accumulation up to a toxic level, which inhibits cell growth on methanol. Lastly, this research provides useful insight for manipulating the EMC pathway for efficiently producing high-value chemicals in M. extorquens.« less

  5. Metabolomics Revealed an Association of Metabolite Changes and Defective Growth in Methylobacterium extorquens AM1 Overexpressing ecm during Growth on Methanol.

    PubMed

    Cui, Jinyu; Good, Nathan M; Hu, Bo; Yang, Jing; Wang, Qianwen; Sadilek, Martin; Yang, Song

    2016-01-01

    Methylobacterium extorquens AM1 is a facultative methylotroph capable of growth on both single-carbon and multi-carbon compounds. The ethylmalonyl-CoA (EMC) pathway is one of the central assimilatory pathways in M. extorquens during growth on C1 and C2 substrates. Previous studies had shown that ethylmalonyl-CoA mutase functioned as a control point during the transition from growth on succinate to growth on ethylamine. In this study we overexpressed ecm, phaA, mcmAB and found that upregulating ecm by expressing it from the strong constitutive mxaF promoter caused a 27% decrease in growth rate on methanol compared to the strain with an empty vector. Targeted metabolomics demonstrated that most of the central intermediates in the ecm over-expressing strain did not change significantly compared to the control strain; However, poly-β-hydroxybutyrate (PHB) was 4.5-fold lower and 3-hydroxybutyryl-CoA was 1.6-fold higher. Moreover, glyoxylate, a toxic and highly regulated essential intermediate, was determined to be 2.6-fold higher when ecm was overexpressed. These results demonstrated that overexpressing ecm can manipulate carbon flux through the EMC pathway and divert it from the carbon and energy storage product PHB, leading to an accumulation of glyoxylate. Furthermore, untargeted metabolomics discovered two unusual metabolites, alanine (Ala)-meso-diaminopimelic acid (mDAP) and Ala-mDAP-Ala, each over 45-fold higher in the ecm over-expressing strain. These two peptides were also found to be highly produced in a dose-dependent manner when glyoxylate was added to the control strain. Overall, this work has explained a direct association of ecm overexpression with glyoxylate accumulation up to a toxic level, which inhibits cell growth on methanol. This research provides useful insight for manipulating the EMC pathway for efficiently producing high-value chemicals in M. extorquens. PMID:27116459

  6. Growth

    NASA Astrophysics Data System (ADS)

    Waag, Andreas

    , molecular beam epitaxy (MBE) delivers high quality ZnMgO-ZnO quantum well structures. Other thin film techniques such as PLD or MOCVD are also widely used. The main problem at present is to consistently achieve reliable p-type doping. For this topic, see also Chap. 5. In the past years, there have been numerous publications on p-type doping of ZnO, as well as ZnO p-n junctions and light emitting diodes (LEDs). However, a lot of these reports are in one way or the other inconsistent or at least incomplete. It is quite clear from optical data that once a reliable hole injection can be achieved, high brightness ZnO LEDs should be possible. In contrast to that expectation, none of the LEDs reported so far shows efficient light emission, as would be expected from a reasonable quality ZnO-based LED. See also Chap. 13. As a matter of fact, there seems to be no generally accepted and reliable technique for p-type doping available at present. The reason for this is the unfavorable position of the band structure of ZnO relative to the vacuum level, with a very low lying valence band. See also Fig. 5.1. This makes the incorporation of electrically active acceptors difficult. Another difficulty is the huge defect density in ZnO. There are many indications that defects play a major role in transport and doping. In order to solve the doping problem, it is generally accepted that the quality of the ZnO material grown by the various techniques needs to be improved. Therefore, the optimization of ZnO epitaxy is thought to play a key role in the further development of this material system. Besides being used as an active material in optoelectronic devices, ZnO plays a major role as transparent contact material in thin film solar cells. Polycrystalline, heavily n-type doped ZnO is used for this, combining a high electrical conductivity with a good optical transparency. In this case, ZnO thin films are fabricated by large area growth techniques such as sputtering. For this and other

  7. Denitrification characteristics of a marine origin psychrophilic aerobic denitrifying bacterium.

    PubMed

    Zheng, Haiyan; Liu, Ying; Sun, Guangdong; Gao, Xiyan; Zhang, Qingling; Liu, Zhipei

    2011-01-01

    A psychrophilic aerobic denitrifying bacterium, strain S1-1, was isolated from a biological aerated filter conducted for treatment of recirculating water in a marine aquaculture system. Strain S1-1 was preliminarily identified as Psychrobacter sp. based on the analysis of its 16S rRNA gene sequence, which showed 100% sequence similarity to that of Psychrobacter sp. TSBY-70. Strain S1-1 grew well either in high nitrate or high nitrite conditions with a removal of 100% nitrate or 63.50% nitrite, and the total nitrogen removal rates could reach to 46.48% and 31.89%, respectively. The results indicated that nitrate was mainly reduced in its logarithmic growth phase with a very low level accumulation of nitrite, suggesting that the aerobic denitrification process of strain S1-1 occurred mainly in this phase. The GC-MS results showed that N2O was formed as the major intermediate during the aerobic denitrifying process of strain S1-1. Finally, factors affecting the growth of strain S1-1 and its aerobic denitrifying ability were also investigated. Results showed that the optimum aerobic denitrification conditions for strain S1-1 were sodium succinate as carbon source, C/N ratio15, salinity 10 g/L NaCl, incubation temperature 20 degrees C and initial pH 6.5. PMID:22432315

  8. A domain of human immunodeficiency virus type 1 Vpr containing repeated H(S/F)RIG amino acid motifs causes cell growth arrest and structural defects.

    PubMed Central

    Macreadie, I G; Castelli, L A; Hewish, D R; Kirkpatrick, A; Ward, A C; Azad, A A

    1995-01-01

    Vpr is a virion-associated protein of human immunodeficiency type 1 (HIV-1) whose function in acquired immunodeficiency syndrome (AIDS) has been uncertain. Employing the yeast Saccharomyces cerevisiae as a model to examine the effects of HIV-1 auxiliary proteins on basic cellular functions, we found that the vpr gene caused cell growth arrest and structural defects indicated by osmotic sensitivity and gross cell enlargement. Production of various domains by gene expression showed that this effect arose from within the carboxyl-terminal third of the Vpr protein and implicated the sequence HFRIGCRHSRIG, containing two H(S/F)RIG motifs. Electroporation with a series of peptides containing these motifs caused structural defects in yeast that resulted in osmotic sensitivity. A protein with functions relating to the yeast cytoskeleton, Sac1p [Cleves, A. E., Novick, P.J. & Bankaitis, V.A. (1989) J. Cell Biol. 109, 2939-2950], shows sequence similarity to Vpr, and Vpr's effect in yeast may be to disrupt normal Sac1p functions. The Sac1p equivalent has not yet been described in mammalian cells, but in rhabdomyosarcoma and osteosarcoma cell lines Vpr also caused gross cell enlargement and replication arrest [Levy, D.N., Fernandes, L.S., Williams, W.V. & Weiner, D.B. (1993) Cell 72, 541-550]. We note that there is a correlation between the region containing the H(S/F)RIG motifs and the pathogenicity of primate lentiviruses and we suggest that the function of Vpr may be to bring about cell growth arrest and/or cytoskeletal changes as an early step in HIV-1 infection. Images Fig. 2 Fig. 3 Fig. 4 Fig. 6 Fig. 7 PMID:7708721

  9. Overexpression of 3β-Hydroxysteroid Dehydrogenases/C-4 Decarboxylases Causes Growth Defects Possibly Due to Abnormal Auxin Transport in Arabidopsis

    PubMed Central

    Kim, Bokyung; Kim, Gyusik; Fujioka, Shozo; Takatsuto, Suguru; Choe, Sunghwa

    2012-01-01

    Sterols play crucial roles as membrane components and precursors of steroid hormones (e.g., brassinosteroids, BR). Within membranes, sterols regulate membrane permeability and fluidity by interacting with other lipids and proteins. Sterols are frequently enriched in detergent-insoluble membranes (DIMs), which organize molecules involved in specialized signaling processes, including auxin transporters. To be fully functional, the two methyl groups at the C-4 position of cycloartenol, a precursor of plant sterols, must be removed by bifunctional 3β-hydroxysteroid dehydrogenases/C-4 decarboxylases (3βHSD/D). To understand the role of 3βHSD/D in Arabidopsis development, we analyzed the phenotypes of knock-out mutants and overexpression lines of two 3βHSD/D genes (At1g47290 and At2g26260). Neither single nor double knock-out mutants displayed a noticeable phenotype; however, overexpression consistently resulted in plants with wrinkled leaves and short inflorescence internodes. Interestingly, the internode growth defects were opportunistic; even within a plant, some stems were more severely affected than others. Endogenous levels of BRs were not altered in the overexpression lines, suggesting that the growth defect is not primarily due to a flaw in BR biosynthesis. To determine if overexpression of the sterol biosynthetic genes affects the functions of membrane-localized auxin transporters, we subjected plants to the auxin efflux carrier inhibitor, 1-N-naphthylphthalamic acid (NPA). Whereas the gravity vectors of wild-type roots became randomly scattered in response to NPA treatment, those of the over-expression lines continued to grow in the direction of gravity. Overexpression of the two Arabidopsis 3βHSD/D genes thus appears to affect auxin transporter activity, possibly by altering sterol composition in the membranes. PMID:22673766

  10. In situ growth and coalescence of He-filled bi-dimensional defects in Si by H supply

    SciTech Connect

    Vallet, M.; Barbot, J. F. Beaufort, M. F.; Oliviero, E.; Donnelly, S. E.; Hinks, J. A.

    2014-06-14

    In this work, ion implantations with in situ transmission electron microscopy observations followed by different rates of temperature ramp were performed in (001)-Si to follow the evolution of He-plates under the influence of hydrogen. The JANNUS and MIAMI facilities were used to study the first stages of growth as well as the interactions between co-planar plates. Results showed that under a limited amount of H, the growth of He-plates resulting from a subcritical stress-corrosion mechanism can be fully described by the kinetic model of Johnson-Mehl-Avrami-Kolmogorov with effective activation energy of 0.9 eV. Elastic calculations showed that the sudden and non-isotropic coalescence of close He-plates occurs when the out-of-plane tensile stress between them is close to the yield strength of silicon. After hydrogen absorption, surface minimization of final structure occurs.

  11. In situ growth and coalescence of He-filled bi-dimensional defects in Si by H supply

    NASA Astrophysics Data System (ADS)

    Vallet, M.; Barbot, J. F.; Oliviero, E.; Donnelly, S. E.; Hinks, J. A.; Beaufort, M. F.

    2014-06-01

    In this work, ion implantations with in situ transmission electron microscopy observations followed by different rates of temperature ramp were performed in (001)-Si to follow the evolution of He-plates under the influence of hydrogen. The JANNUS and MIAMI facilities were used to study the first stages of growth as well as the interactions between co-planar plates. Results showed that under a limited amount of H, the growth of He-plates resulting from a subcritical stress-corrosion mechanism can be fully described by the kinetic model of Johnson-Mehl-Avrami-Kolmogorov with effective activation energy of 0.9 eV. Elastic calculations showed that the sudden and non-isotropic coalescence of close He-plates occurs when the out-of-plane tensile stress between them is close to the yield strength of silicon. After hydrogen absorption, surface minimization of final structure occurs.

  12. Analysis of the Legionella pneumophila fliI gene: intracellular growth of a defined mutant defective for flagellum biosynthesis.

    PubMed Central

    Merriam, J J; Mathur, R; Maxfield-Boumil, R; Isberg, R R

    1997-01-01

    Using a PCR-based strategy and degenerate oligonucleotides, we isolated a Legionella pneumophila gene that showed high sequence similarity to members of the fliI gene family. An insertion mutation that disrupted the fliI open reading frame was recombined onto the L. pneumophila chromosome and analyzed for its effects on production of flagella and intracellular growth. The mutation resulted in loss of surface-localized flagellin protein but had no effect on the ability of the bacteria to grow within cultured cells. Therefore, in spite of the fact that some aflagellar mutations render L. pneumophila unable to grow within macrophages, the isolation of this defined mutant confirms that production of flagella is not required for intracellular growth. PMID:9169800

  13. The Bradyrhizobium japonicum Ferrous Iron Transporter FeoAB Is Required for Ferric Iron Utilization in Free Living Aerobic Cells and for Symbiosis.

    PubMed

    Sankari, Siva; O'Brian, Mark R

    2016-07-22

    The bacterium Bradyrhizobium japonicum USDA110 does not synthesize siderophores for iron utilization in aerobic environments, and the mechanism of iron uptake within symbiotic soybean root nodules is unknown. An mbfA bfr double mutant defective in iron export and storage activities cannot grow aerobically in very high iron medium. Here, we found that this phenotype was suppressed by loss of function mutations in the feoAB operon encoding ferrous (Fe(2+)) iron uptake proteins. Expression of the feoAB operon genes was elevated under iron limitation, but mutants defective in either gene were unable to grow aerobically over a wide external ferric (Fe(3+)) iron (FeCl3) concentration range. Thus, FeoAB accommodates iron acquisition under iron limited and iron replete conditions. Incorporation of radiolabel from either (55)Fe(2+) or (59)Fe(3+) into cells was severely defective in the feoA and feoB strains, suggesting Fe(3+) reduction to Fe(2+) prior to traversal across the cytoplasmic membrane by FeoAB. The feoA or feoB deletion strains elicited small, ineffective nodules on soybean roots, containing few bacteria and lacking nitrogen fixation activity. A feoA(E40K) mutant contained partial iron uptake activity in culture that supported normal growth and established an effective symbiosis. The feoA(E40K) strain had partial iron uptake activity in situ within nodules and in isolated cells, indicating that FeoAB is the iron transporter in symbiosis. We conclude that FeoAB supports iron acquisition under limited conditions of soil and in the iron-rich environment of a symbiotic nodule. PMID:27288412

  14. Ear defects.

    PubMed

    Shonka, David C; Park, Stephen S

    2009-08-01

    The projection and exposure of the auricle make it particularly susceptible to actinic injury and thus to cutaneous malignancies. Auricular reconstruction is challenging because of its unique surface anatomy and undulating topography. This article organizes auricular defects into different categories based on anatomic location and extent of tissue loss, including skin-only defects, small composite defects, full-thickness defects involving or sparing the upper third of the ear, and total auricular loss. The authors share an algorithm for repair of the array of auricular defects. PMID:19698921

  15. Genome-wide redistribution of H3K27me3 is linked to genotoxic stress and defective growth

    PubMed Central

    Basenko, Evelina Y.; Sasaki, Takahiko; Ji, Lexiang; Prybol, Cameron J.; Burckhardt, Rachel M.; Schmitz, Robert J.; Lewis, Zachary A.

    2015-01-01

    H3K9 methylation directs heterochromatin formation by recruiting multiple heterochromatin protein 1 (HP1)-containing complexes that deacetylate histones and methylate cytosine bases in DNA. In Neurospora crassa, a single H3K9 methyltransferase complex, called the DIM-5,-7,-9, CUL4, DDB1 Complex (DCDC), is required for normal growth and development. DCDC-deficient mutants are hypersensitive to the genotoxic agent methyl methanesulfonate (MMS), but the molecular basis of genotoxic stress is unclear. We found that both the MMS sensitivity and growth phenotypes of DCDC-deficient strains are suppressed by mutation of embryonic ectoderm development or Su-(var)3-9; E(z); Trithorax (set)-7, encoding components of the H3K27 methyltransferase Polycomb repressive complex-2 (PRC2). Trimethylated histone H3K27 (H3K27me3) undergoes genome-wide redistribution to constitutive heterochromatin in DCDC- or HP1-deficient mutants, and introduction of an H3K27 missense mutation is sufficient to rescue phenotypes of DCDC-deficient strains. Accumulation of H3K27me3 in heterochromatin does not compensate for silencing; rather, strains deficient for both DCDC and PRC2 exhibit synthetic sensitivity to the topoisomerase I inhibitor Camptothecin and accumulate γH2A at heterochromatin. Together, these data suggest that PRC2 modulates the response to genotoxic stress. PMID:26578794

  16. Genome-wide redistribution of H3K27me3 is linked to genotoxic stress and defective growth.

    PubMed

    Basenko, Evelina Y; Sasaki, Takahiko; Ji, Lexiang; Prybol, Cameron J; Burckhardt, Rachel M; Schmitz, Robert J; Lewis, Zachary A

    2015-11-17

    H3K9 methylation directs heterochromatin formation by recruiting multiple heterochromatin protein 1 (HP1)-containing complexes that deacetylate histones and methylate cytosine bases in DNA. In Neurospora crassa, a single H3K9 methyltransferase complex, called the DIM-5,-7,-9, CUL4, DDB1 Complex (DCDC), is required for normal growth and development. DCDC-deficient mutants are hypersensitive to the genotoxic agent methyl methanesulfonate (MMS), but the molecular basis of genotoxic stress is unclear. We found that both the MMS sensitivity and growth phenotypes of DCDC-deficient strains are suppressed by mutation of embryonic ectoderm development or Su-(var)3-9; E(z); Trithorax (set)-7, encoding components of the H3K27 methyltransferase Polycomb repressive complex-2 (PRC2). Trimethylated histone H3K27 (H3K27me3) undergoes genome-wide redistribution to constitutive heterochromatin in DCDC- or HP1-deficient mutants, and introduction of an H3K27 missense mutation is sufficient to rescue phenotypes of DCDC-deficient strains. Accumulation of H3K27me3 in heterochromatin does not compensate for silencing; rather, strains deficient for both DCDC and PRC2 exhibit synthetic sensitivity to the topoisomerase I inhibitor Camptothecin and accumulate γH2A at heterochromatin. Together, these data suggest that PRC2 modulates the response to genotoxic stress. PMID:26578794

  17. Aerobic and anaerobic microbiology of infections after trauma in children.

    PubMed Central

    Brook, I

    1998-01-01

    OBJECTIVE: To review the recovery of aerobic and anaerobic bacteria from infections after trauma in children over a 20 year period. METHODS: Only specimens that were studied for both aerobic and anaerobic bacteria were included in the analysis. They were collected from seven separate centres in which the microbiology laboratories only accepted specimens that were properly collected without contamination and were submitted in appropriate transport media. Anaerobes and aerobic bacteria were cultured and identified using standard techniques. Clinical records were reviewed to identify post-trauma patients. RESULTS: From 1974 to 1994, 175 specimens obtained from 166 children with trauma showed bacterial growth. The trauma included blunt trauma (71), lacerations (48), bites (42), and open fractures (5). Anaerobic bacteria only were isolated in 38 specimens (22%), aerobic bacteria only in 51 (29%), and mixed aerobic-anaerobic flora in 86 (49%); 363 anaerobic (2.1/specimen) and 158 aerobic or facultative isolates (0.9/specimen) were recovered. The predominant anaerobic bacteria included Peptostreptococcus spp (115 isolates), Prevotella spp (68), Fusobacterium spp (52), B fragilis group (42), and Clostridium spp (21). The predominant aerobic bacteria included Staph aureus (51), E coli (13), Ps aeruginosa (12), Str pyogenes (11) and Klebsiella pneumoniae (9). Principal infections were: abscesses (52), bacteraemia (3), pulmonary infections (30, including aspiration pneumonia, tracheostomy associated pneumonia, empyema, and ventilator associated pneumonia), wounds (36, including cellulitis, post-traumatic wounds, decubitus ulcers, myositis, gastrostomy and tracheostomy site wounds, and fasciitis), bites (42, including 23 animal and 19 human), peritonitis (4), osteomyelitis (5), and sinusitis (3). Staph aureus and Str pyogenes were isolated at all sites. However, organisms of the oropharyngeal flora predominated in infections that originated from head and neck wounds and

  18. Beneficial effects of growth hormone therapy for ossification defects after bone distraction in X linked hypophosphataemic rickets

    PubMed Central

    Cañete, Ramón; Caballero-Villarraso, Javier; Aguilar-Quintero, María; Vázquez-Rueda, Fernando

    2014-01-01

    A report on two homozygous twin girls affected by X linked hypophosphataemic rickets. They were examined due to short stature and genu varum of both tibias. They were treated with calcitriol and Joulie's solution, whereon it was observed that serum parathyroid hormone and phosphaturia decreased while phosphataemia increased. They underwent a tibial osteotomy (by means of the insertion of Kirchner needles) at 7.7 years of age for correction of genu varum and a normal consolidation was reached 1 month later. Nonetheless, height was percentile <1 after menarche, so both sisters asked for bone lengthening. Because of this, at 15 years of age femoral distraction was performed, but no bone callus was observed 14 months later. Consequently, they were treated with subcutaneous growth hormone, showing bone callus at 6 months. Finally, the external fixators were removed due to ossification in the lengthened segments. PMID:25115781

  19. An ultra-thin compliant sapphire membrane for the growth of less strained, less defective GaN

    NASA Astrophysics Data System (ADS)

    Moon, Daeyoung; Jang, Jeonghwan; Choi, Daehan; Shin, In-Su; Lee, Donghyun; Bae, Dukkyu; Park, Yongjo; Yoon, Euijoon

    2016-05-01

    An ultra-thin (26 nm) sapphire (Al2O3) membrane was used as a compliant substrate for the growth of high quality GaN. The density of misfit dislocations per unit length at the interface between the GaN layer and the sapphire membrane was reduced by 28% compared to GaN on the conventional sapphire substrate. Threading dislocation density in GaN on the sapphire membrane was measured to be 2.4×108/cm2, which is lower than that for GaN on the conventional sapphire substrate (3.2×108/cm2). XRD and micro-Raman results verifed that the residual stress in GaN on the sapphire membrane was as low as 0.02 GPa due to stress absorption by the ultra-thin compliant sapphire membrane.

  20. Pancreatic Ductal Adenocarcinoma (PDA) mice lacking Mucin 1 have a profound defect in tumor growth and metastasis

    PubMed Central

    Besmer, Dahlia M.; Curry, Jennifer M.; Roy, Lopamudra D.; Tinder, Teresa L.; Sahraei, Mahnaz; Schettini, Jorge; Hwang, Sun-Il; Lee, Yong Y.; Gendler, Sandra J.; Mukherjee, Pinku

    2011-01-01

    MUC1 is over expressed and aberrantly glycosolated in >60% of pancreatic ductal adenocarcinomas. The functional role of MUC1 in pancreatic cancer has yet to be fully elucidated due to a dearth of appropriate models. In the present study, we have generated mouse models that spontaneously develop pancreatic ductal adenocarcinoma (KC), which are either Muc1-null (KCKO) or express human MUC1 (KCM). We show that KCKO mice have significantly slower tumor progression and rates of secondary metastasis, compared to both KC and KCM. Cell lines derived from KCKO tumors have significantly lower tumorigenic capacity compared to cells from KCM tumors. Therefore, mice with KCKO tumors had a significant survival benefit compared to mice with KCM tumors. In vitro, KCKO cells have reduced proliferation and invasion and failed to respond to epidermal growth factor (EGF), platelet-derived growth factor (PDGF), or matrix metalloproteinase-9 (MMP9). Further, significantly fewer KCKO cells entered the G2M phase of the cell cycle compared to the KCM cells. Proteomics and western blotting analysis revealed a complete loss of cdc-25c expression, phosphorylation of MAPK, as well as a significant decrease in Nestin and Tubulin α-2 chain expression in KCKO cells. Treatment with a MEK1/2 inhibitor, U0126, abrogated the enhanced proliferation of the KCM cells but had minimal effect on KCKO cells, suggesting that MUC1 is necessary for MAPK activity and oncogenic signaling. This is the first study to utilize a Muc1-null PDA mouse in order to fully elucidate the oncogenic role of MUC1, both in vivo and in vitro. PMID:21558393

  1. Deregulation of the OsmiR160 Target Gene OsARF18 Causes Growth and Developmental Defects with an Alteration of Auxin Signaling in Rice.

    PubMed

    Huang, Jian; Li, Zhiyong; Zhao, Dazhong

    2016-01-01

    MicroRNAs (miRNAs) control gene expression as key negative regulators at the post-transcriptional level. MiR160 plays a pivotal role in Arabidopsis growth and development through repressing expression of its target AUXIN RESPONSE FACTOR (ARF) genes; however, the function of miR160 in monocots remains elusive. In this study, we found that the mature rice miR160 (OsmiR160) was mainly derived from OsMIR160a and OsMIR160b genes. Among four potential OsmiR160 target OsARF genes, the OsARF18 transcript was cleaved at the OsmiR160 target site. Rice transgenic plants (named mOsARF18) expressing an OsmiR160-resistant version of OsARF18 exhibited pleiotropic defects in growth and development, including dwarf stature, rolled leaves, and small seeds. mOsARF18 leaves were abnormal in bulliform cell differentiation and epidermal cell division. Starch accumulation in mOsARF18 seeds was also reduced. Moreover, auxin induced expression of OsMIR160a, OsMIR160b, and OsARF18, whereas expression of OsMIR160a and OsMIR160b as well as genes involved in auxin signaling was altered in mOsARF18 plants. Our results show that negative regulation of OsARF18 expression by OsmiR160 is critical for rice growth and development via affecting auxin signaling, which will advance future studies on the molecular mechanism by which miR160 fine-tunes auxin signaling in plants. PMID:27444058

  2. Defect formation in Cu(In,Ga)Se{sub 2} thin films due to the presence of potassium during growth by low temperature co-evaporation process

    SciTech Connect

    Pianezzi, F. Reinhard, P.; Chirilă, A.; Nishiwaki, S.; Bissig, B.; Buecheler, S.; Tiwari, A. N.

    2013-11-21

    Doping the Cu(In,Ga)Se{sub 2} (CIGS) absorber layer with alkaline metals is necessary to process high efficiency solar cells. When growth of CIGS solar cells is performed on soda-lime glass (SLG), the alkaline elements naturally diffuse from the substrate into the absorber layer. On the other hand, when CIGS is grown on alkaline free substrates, the alkaline metals have to be added from another source. In the past, Na was believed to be the most important dopant of the alkaline elements, even though K was also observed to diffuse into CIGS from the SLG. Recently, the beneficial effect of a post deposition treatment with KF was pointed out and enabled the production of a 20.4% CIGS solar cell grown at low substrate temperature (<500 °C). However, possible negative effects of the presence or addition of the alkaline impurities during the low temperature growth process were observed for Na, but were not investigated for K so far. In this study, we investigate in detail the role of K on the defect formation in CIGS layers deposited at low temperature on alkaline free polyimide with intentional addition of K during selected time intervals of the CIGS layer growth. By means of admittance spectroscopy and deep level transient spectroscopy, we identify a deep minority carrier trap at around 280 meV below the conduction band E{sub C} in CIGS layers grown with K. Its influence on recombination and minority carrier lifetime in the absorber layer is investigated with external quantum efficiency measurements and time-resolved photoluminescence. Furthermore, to support the experimental findings device simulations were performed using the software SCAPS.

  3. Deregulation of the OsmiR160 Target Gene OsARF18 Causes Growth and Developmental Defects with an Alteration of Auxin Signaling in Rice

    PubMed Central

    Huang, Jian; Li, Zhiyong; Zhao, Dazhong

    2016-01-01

    MicroRNAs (miRNAs) control gene expression as key negative regulators at the post-transcriptional level. MiR160 plays a pivotal role in Arabidopsis growth and development through repressing expression of its target AUXIN RESPONSE FACTOR (ARF) genes; however, the function of miR160 in monocots remains elusive. In this study, we found that the mature rice miR160 (OsmiR160) was mainly derived from OsMIR160a and OsMIR160b genes. Among four potential OsmiR160 target OsARF genes, the OsARF18 transcript was cleaved at the OsmiR160 target site. Rice transgenic plants (named mOsARF18) expressing an OsmiR160-resistant version of OsARF18 exhibited pleiotropic defects in growth and development, including dwarf stature, rolled leaves, and small seeds. mOsARF18 leaves were abnormal in bulliform cell differentiation and epidermal cell division. Starch accumulation in mOsARF18 seeds was also reduced. Moreover, auxin induced expression of OsMIR160a, OsMIR160b, and OsARF18, whereas expression of OsMIR160a and OsMIR160b as well as genes involved in auxin signaling was altered in mOsARF18 plants. Our results show that negative regulation of OsARF18 expression by OsmiR160 is critical for rice growth and development via affecting auxin signaling, which will advance future studies on the molecular mechanism by which miR160 fine-tunes auxin signaling in plants. PMID:27444058

  4. Growth Temperature Dependence of Si Doping Efficiency and Compensating Deep Level Defect Incorporation in Al0.7Ga0.3N

    SciTech Connect

    Armstrong, Andrew; Moseley, Michael William; Allerman, Andrew A.; Crawford, Mary H.; Wierer, Jonathan

    2015-05-11

    The growth temperature dependence of Si doping efficiency and deep level defect formation was investigated for n-type Al0.7Ga0.3N. It was observed that dopant compensation was greatly reduced with reduced growth temperature. Furthermore, deep level optical spectroscopy and lighted capacitance-voltage were used to understand the role of acceptor-like deep level defects on doping efficiency. Deep level defects were observed at 2.34 eV, 3.56 eV, and 4.74 eV below the conduction band minimum. The latter two deep levels were identified as the major compensators because the reduction in their concentrations at reduced growth temperature correlated closely with the concomitant increase in free electron concentration. Possible mechanisms for the strong growth temperature dependence of deep level formation are considered, which includes thermodynamically driven compensating defect formation that can arise for a semiconductor with very large band gap energy, such as Al0.7Ga0.3N.

  5. Aerobic exercise augments muscle transcriptome profile of resistance exercise.

    PubMed

    Lundberg, Tommy R; Fernandez-Gonzalo, Rodrigo; Tesch, Per A; Rullman, Eric; Gustafsson, Thomas

    2016-06-01

    Recent reports suggest that aerobic exercise may boost the hypertrophic response to short-term resistance training. This study explored the effects of an acute aerobic exercise bout on the transcriptional response to subsequent resistance exercise. Ten moderately trained men performed ∼45 min cycling on one leg followed by 4 × 7 maximal knee extensions for each leg, 15 min later. Thus, one limb performed aerobic and resistance exercise (AE + RE) while the opposing leg did resistance exercise only (RE). Biopsies were obtained from the vastus lateralis muscle of each leg 3 h after the resistance exercise bout. Using DNA microarray, we analyzed differences [≥1.5-fold, false discovery rate (FDR) ≤10%] in gene expression profiles for the two modes of exercise. There were 176 genes up (127)- or downregulated (49) by AE + RE compared with RE. Among the most significant differentially expressed genes were established markers for muscle growth and oxidative capacity, novel cytokines, transcription factors, and micro-RNAs (miRNAs). The most enriched functional categories were those linked to carbohydrate metabolism and transcriptional regulation. Upstream analysis revealed that vascular endothelial growth factor, cAMP-response element-binding protein, Tet methylcytosine dioxygenase, and mammalian target of rapamycin were regulators highly activated by AE + RE, whereas JnK, NF-κβ, MAPK, and several miRNAs were inhibited. Thus, aerobic exercise alters the skeletal muscle transcriptional signature of resistance exercise to initiate important gene programs promoting both myofiber growth and improved oxidative capacity. These results provide novel insight into human muscle adaptations to diverse exercise modes and offer the very first genomic basis explaining how aerobic exercise may augment, rather than compromise, muscle growth induced by resistance exercise. PMID:27101291

  6. Growth properties and vaccine efficacy of recombinant pseudorabies virus defective in glycoprotein E and thymidine kinase genes.

    PubMed

    Wu, Ching-Ying; Liao, Chih-Ming; Chi, Jiun-Ni; Chien, Maw-Sheng; Huang, Chienjin

    2016-07-10

    Pseudorabies virus (PRV) is an alphaherpesvirus that causes pseudorabies (PR), an economically important viral disease of pigs. Marker vaccines were widely used in PR prevention and eradication programs. The purpose of this study was to construct a novel recombinant virus with deletions at defined regions in the glycoprotein E (gE) and thymine kinase (TK) genes by homologous recombination. This study also evaluated the safety and efficacy of the virus for a live attenuated marker vaccine. No significant difference was observed in virus replication between gE gene-deleted (gE(-)), gE/TK double gene-deleted (gE(-)TK(-)), and wild-type PRV by growth curve analysis. However, gE(-)TK(-) PRV was completely attenuated in mice. To evaluate the immunogenicity of gE(-)TK(-) PRV, four 12-week-old specific-pathogen-free pigs per group were immunized intramuscularly with viral titers of 1×10(4), 1×10(5), or 1×10(6) TCID50, followed by intranasal challenge infection with virulent PRV (1×10(8) TCID50) at 3 weeks post vaccination. The gE(-)TK(-) PRV-vaccinated pigs displayed no general adverse effects after immunization and had protective immune responses after PRV challenge. Thus, gE(-)TK(-) PRV was safe and efficacious and might be a potential candidate for a live attenuated marker vaccine against PRV. PMID:27164258

  7. Effect of short-time aerobic digestion on bioflocculation of extracellular polymeric substances from waste activated sludge.

    PubMed

    Zhang, Zhiqiang; Zhang, Jiao; Zhao, Jianfu; Xia, Siqing

    2015-02-01

    The effect of short-time aerobic digestion on bioflocculation of extracellular polymeric substances (EPSs) from waste activated sludge (WAS) was investigated. Bioflocculation of the EPS was found to be enhanced by 2∼6 h of WAS aerobic digestion under the conditions of natural sludge pH (about 7), high sludge concentration by gravity thickening, and dissolved oxygen of about 2 mg/L. With the same EPS extraction method, the total suspended solid content reduction of 0.20 and 0.36 g/L and the volatile suspended solid content reduction of 0.19 and 0.26 g/L were found for the WAS samples before and after aerobic digestion of 4 h. It indicates that more EPS is produced by short-time aerobic digestion of WAS. The scanning electron microscopy images of the WAS samples before and after aerobic digestion of 4 h showed that more EPS appeared on the surface of zoogloea by aerobic digestion, which reconfirmed that WAS aerobic digestion induced abundant formation of EPS. By WAS aerobic digestion, the flocculating rate of the EPS showed about 31 % growth, almost consistent with the growth of its yield (about 34 %). The EPSs obtained before and after the aerobic digestion presented nearly the same components, structures, and Fourier transform infrared spectra. These results revealed that short-time aerobic digestion of WAS enhanced the flocculation of the EPS by promoting its production. PMID:23771440

  8. Sequence-Based Identification of Aerobic Actinomycetes

    PubMed Central

    Patel, Jean Baldus; Wallace, Richard J.; Brown-Elliott, Barbara A.; Taylor, Tony; Imperatrice, Carol; Leonard, Deborah G. B.; Wilson, Rebecca W.; Mann, Linda; Jost, Kenneth C.; Nachamkin, Irving

    2004-01-01

    We investigated the utility of 500-bp 16S rRNA gene sequencing for identifying clinically significant species of aerobic actinomycetes. A total of 28 reference strains and 71 clinical isolates that included members of the genera Streptomyces, Gordonia, and Tsukamurella and 10 taxa of Nocardia were studied. Methods of nonsequencing analyses included growth and biochemical analysis, PCR-restriction enzyme analysis of the 439-bp Telenti fragment of the 65 hsp gene, susceptibility testing, and, for selected isolates, high-performance liquid chromatography. Many of the isolates were included in prior taxonomic studies. Sequencing of Nocardia species revealed that members of the group were generally most closely related to the American Type Culture Collection (ATCC) type strains. However, the sequences of Nocardia transvalensis, N. otitidiscaviarum, and N. nova isolates were highly variable; and it is likely that each of these species contains multiple species. We propose that these three species be designated complexes until they are more taxonomically defined. The sequences of several taxa did not match any recognized species. Among other aerobic actinomycetes, each group most closely resembled the associated reference strain, but with some divergence. The study demonstrates the ability of partial 16S rRNA gene sequencing to identify members of the aerobic actinomycetes, but the study also shows that a high degree of sequence divergence exists within many species and that many taxa within the Nocardia spp. are unnamed at present. A major unresolved issue is the type strain of N. asteroides, as the present one (ATCC 19247), chosen before the availability of molecular analysis, does not represent any of the common taxa associated with clinical nocardiosis. PMID:15184431

  9. Defect structures and growth mechanisms of boron arsenide epilayers grown on 6H-silicon carbide and 15R-silicon carbide substrates

    NASA Astrophysics Data System (ADS)

    Chen, Hui

    B12As2 possesses the extraordinary properties, such as wide bandgap of 3.47eV and unique 'self heal' ability from electron irradiation damage, which make it attractive for the applications in space electronics, high temperature semiconductors and in particular, beta cells, devices capable of producing electrical energy by coupling a radioactive beta emitter to a semiconductor junction. Due to the absence of native substrates, B12As2 has been grown on substrates with compatible structural parameters via chemical vapor deposition. To date, growth on Si with (100), (110) and (111) orientation and (0001) 6H-SiC has been attempted. However, structural variants, including rotational and translational variants, have been observed in the epilayers and are expected to have a detrimental effect on device performance which has severely hindered progress of this material to date. In addition, none of the earlier reports provide a detailed atomic level study of defect structures in the films and growth mechanisms remain obscure. The focus of this thesis is to study defect structures in B12As2 films grown on different SiC substrates using synchrotron x-ray topography, high resolution transmission microscopy as well as other characterization techniques. The goals of the studies are to understand the generations of the defects present in B12As 2 films and their growth mechanisms so as to develop strategies to reduce defect densities and obtain better film quality for future device fabrication. The following detailed studies have been carried out: (1) The microstructures in B12As2 epitaxial layers grown on on-axis c-plane (0001) 6H-SiC substrates were analyzed in detail. Synchrotron white beam X-ray topography (SWBXT) and scanning electron microscopy (SEM) revealed a mosaic structure consisting of a solid solution of twin and matrix epilayer domains. The epitaxial relationship was determined to be (0001)B12As2<112¯0> B12As2||(0001)6H-SiC<112¯0>6H-SiC. B 12As2 twinned domains were

  10. The Transition from Aerobic to Anaerobic Metabolism.

    ERIC Educational Resources Information Center

    Skinner, James S.; McLellan, Thomas H.

    1980-01-01

    The transition from aerobic to anaerobic metabolism is discussed. More research is needed on different kinds of athletes and athletic activities and how they may affect aerobic and anaerobic metabolisms. (CJ)

  11. Characterization and aerobic biodegradation of selected monoterpenes

    SciTech Connect

    Misra, G.; Pavlostathis, S.G.; Li, J.; Purdue, E.M.

    1996-12-31

    Monoterpenes are biogenic chemicals and occur in abundance in nature. Large-scale industrial use of these chemicals has recently been initiated in an attempt to replace halogenated solvents and chlorofluorocarbons which have been implicated in the stratospheric depletion of ozone. This study examined four hydrocarbon monoterpenes (d-limonene, {alpha}-pinene, {gamma}-terpinene, and terpinolene) and four alcohols (arbanol, linalool, plinol, and {alpha}-terpineol). Water solubility, vapor pressure, and octanol/water partition coefficients were estimated. Aerobic biodegradability tests were conducted in batch reactors by utilizing forest soil extract and enriched cultures as inoculum. The hydrophobic nature and high volatility of the hydrocarbons restricted the investigation to relatively low aqueous concentrations. Each monoterpene was analyzed with a gas chromatograph equipped with a flame ionization detector after extraction from the aqueous phase with isooctane. Terpene mineralization was tested by monitoring liquid-phase carbon, CO{sub 2} production and biomass growth. All four hydrocarbons and two alcohols readily degraded under aerobic conditions. Plinol resisted degradation in assays using inocula from diverse sources, while arbanol degraded very slowly. The intrinsic biokinetics coefficients for the degradation of d-limonene and {alpha}-terpineol were estimated by using cultures enriched with the respective monoterpenes. Monoterpene biodegradation followed Monod kinetics.

  12. Atomic-scale investigation of structural defects in GaN layer on c-plane sapphire substrate during initial growth stage

    NASA Astrophysics Data System (ADS)

    Matsubara, Tohoru; Sugimoto, Kohei; Okada, Narihito; Tadatomo, Kazuyuki

    2016-04-01

    Structural defects in the initial growth stages of GaN on sapphire, including stacking faults (SFs), threading dislocations (TDs), and mosaic structure containing grain boundaries, are investigated at the atomic scale. Individual grains in the as-deposited low temperature-GaN buffer layer are found to have twists correlated with those of the adjacent grains. These grains have little similarity on the stacking sequences, and the atomic arrangement on each side of the grain boundaries may be rearranged by annealing to achieve higher similarity in the stacking sequence. The TD identified as a-type at the top of the SFs-rich interfacial region is thought to originate from Frank partial dislocations. The Frank partial dislocation produces a distorted wurtzite-type structure. At the intermediate region of the basal-plane stacking fault between Frank and Shockley partial dislocations, the TD relieves the distortion in the wurtzite-type structure. In the TD, the wurtzite structure slips relative to the surrounding wurtzite.

  13. Mechanism of β-FeSi2 precipitates growth-and-dissolution and pyramidal defects' formation during oxidation of Fe-contaminated silicon wafers

    NASA Astrophysics Data System (ADS)

    De Luca, Anthony; Texier, Michaël; Portavoce, Alain; Burle, Nelly; Grosjean, Catherine; Morata, Stéphane; Michel, Fabrice

    2015-03-01

    Fe-implanted Si-wafers have been oxidized at 900 °C and 1100 °C in order to investigate the behaviour of Fe atoms at the growing SiO2/Si interface and the impact on the integrity of microelectronic devices of an involuntary Fe contamination before or during the oxidation process. As-implanted and oxidized wafers have been characterized using secondary ion mass spectroscopy, atom probe tomography, and high-resolution transmission electron microscopy. Experimental results were compared to calculated implantation profiles and simulated images. Successive steps of iron disilicide precipitation and oxidation were evidenced during the silicon oxidation process. The formation of characteristic pyramidal-shaped defects, at the SiO2/Si interface, was notably found to correlate with the presence of β-FeSi2 precipitates. Taking into account the competitive oxidation of these precipitates and of the surrounding silicon matrix, dynamic mechanisms are proposed to model the observed microstructural evolution of the SiO2/Si interface, during the growth of the silicon oxide layer.

  14. Mechanism of β-FeSi{sub 2} precipitates growth-and-dissolution and pyramidal defects' formation during oxidation of Fe-contaminated silicon wafers

    SciTech Connect

    De Luca, Anthony; Texier, Michaël Portavoce, Alain; Burle, Nelly; Grosjean, Catherine; Morata, Stéphane; Michel, Fabrice

    2015-03-21

    Fe-implanted Si-wafers have been oxidized at 900 °C and 1100 °C in order to investigate the behaviour of Fe atoms at the growing SiO{sub 2}/Si interface and the impact on the integrity of microelectronic devices of an involuntary Fe contamination before or during the oxidation process. As-implanted and oxidized wafers have been characterized using secondary ion mass spectroscopy, atom probe tomography, and high-resolution transmission electron microscopy. Experimental results were compared to calculated implantation profiles and simulated images. Successive steps of iron disilicide precipitation and oxidation were evidenced during the silicon oxidation process. The formation of characteristic pyramidal-shaped defects, at the SiO{sub 2}/Si interface, was notably found to correlate with the presence of β-FeSi{sub 2} precipitates. Taking into account the competitive oxidation of these precipitates and of the surrounding silicon matrix, dynamic mechanisms are proposed to model the observed microstructural evolution of the SiO{sub 2}/Si interface, during the growth of the silicon oxide layer.

  15. Microtubule-Associated Protein 2, a Marker of Neuronal Differentiation, Induces Mitotic Defects, Inhibits Growth of Melanoma Cells, and Predicts Metastatic Potential of Cutaneous Melanoma

    PubMed Central

    Soltani, Mohammad H.; Pichardo, Rita; Song, Ziqui; Sangha, Namrata; Camacho, Fabian; Satyamoorthy, Kapaettu; Sangueza, Omar P.; Setaluri, Vijayasaradhi

    2005-01-01

    Dynamic instability of microtubules is critical for mitotic spindle assembly and disassembly during cell division, especially in rapidly dividing tumor cells. Microtubule-associated proteins (MAPs) are a family of proteins that influence this property. We showed previously that MAP2, a neuron-specific protein that stabilizes microtubules in the dendrites of postmitotic neurons, is induced in primary cutaneous melanoma but is absent in metastatic melanomas. We proposed that induction of a microtubule-stabilizing protein in primary melanoma could disrupt the dynamic instability of microtubules, inhibit cell division and prevent or delay tumor progression. Here we show, by Kaplan-Meier survival and multivariate Cox regression analysis, that patients diagnosed with MAP2+ primary melanomas have significantly better metastatic disease-free survival than those with MAP2− disease. Investigation of the mechanisms that underlie the effect of MAP2 on melanoma progression showed that MAP2 expression in metastatic melanoma cell lines leads to microtubule stabilization, cell cycle arrest in G2-M phase and growth inhibition. Disruption of microtubule dynamics by MAP2 resulted in multipolar mitotic spindles, defects in cytokinesis and accumulation of cells with large nuclei, similar to those seen in vivo in MAP2+ primary melanomas cells. These data suggest that ectopic activation of a neuronal differentiation gene in melanoma during early tumor progression inhibits cell division and correlates with inhibition or delay of metastasis. PMID:15920168

  16. Expression of a putative ATPase suppresses the growth defect of a yeast potassium transport mutant: identification of a mammalian member of the Clp/HSP104 family.

    PubMed

    Périer, F; Radeke, C M; Raab-Graham, K F; Vandenberg, C A

    1995-01-23

    A cDNA encoding a novel mammalian member of the Clp/HSP104 family was isolated from a mouse macrophage-like cell line (J774.1) cDNA library by suppression of the growth defect of a Saccharomyces cerevisiae trk1 trk2 double mutant. The full-length version of this cDNA, termed SKD3, encodes a putative 76-kDa protein of 677 amino acids (aa). The deduced aa sequence of the SKD3 polypeptide contains four ankyrin-like repeats in the N-terminal domain and a single ATP-binding consensus site in the C-terminal domain. The 378-aa C-terminal domain of SKD3 has 57-64% similarity (30-40% identity) with members of the Clp/HSP104 family, including the ClpA regulatory subunit of the Clp protease and S. cerevisiae heat-shock protein 104. Northern analysis showed that the 2.3-kb SKD3 transcript is present in a wide variety of tissues, is abundant in mouse heart, skeletal muscle and kidney, and is most abundant in testis. Members of the Clp/HSP104 family have been identified previously from bacteria, yeast and chloroplasts, and are ATPases regulating Clp protease activity and specificity, or mediating cellular responses involved in thermotolerance. SKD3 is the first member of this protein family identified in a higher eukaryote. PMID:7835694

  17. Birth Defects

    MedlinePlus

    ... with birth defects may need surgery or other medical treatments. Today, doctors can diagnose many birth defects in the womb. This enables them to treat or even correct some problems before the baby is born. Centers for Disease Control and Prevention

  18. "Aerobic" Writing: A Writing Practice Model.

    ERIC Educational Resources Information Center

    Crisp, Sally Chandler

    "Aerobic writing" is a writing center strategy designed to keep students in writing "shape." Like aerobic exercise, aerobic writing is sustained for a certain length of time and done on a regular basis at prescribed time intervals. The program requires students to write at least two times a week for approximately an hour each time. Students write,…

  19. Arthritis and Aerobic Exercise: A Review.

    ERIC Educational Resources Information Center

    Ike, Robert W.; And Others

    1989-01-01

    Arthritic patients who regularly do aerobic exercise make significant gains in aerobic and functional status, and in subjective areas like pain tolerance and mood. Still, they are often advised to curtail physical activity. Guidelines are presented for physicians prescribing aerobic exercise. An exercise tolerance test is recommended. (SM)

  20. Degradation of TCE using sequential anaerobic biofilm and aerobic immobilized bed reactor

    NASA Technical Reports Server (NTRS)

    Chapatwala, Kirit D.; Babu, G. R. V.; Baresi, Larry; Trunzo, Richard M.

    1995-01-01

    Bacteria capable of degrading trichloroethylene (TCE) were isolated from contaminated wastewaters and soil sites. The aerobic cultures were identified as Pseudomonas aeruginosa (four species) and Pseudomonas fluorescens. The optimal conditions for the growth of aerobic cultures were determined. The minimal inhibitory concentration values of TCE for Pseudomonas sps. were also determined. The aerobic cells were immobilized in calcium alginate in the form of beads. Degradation of TCE by the anaerobic and dichloroethylene (DCE) by aerobic cultures was studied using dual reactors - anaerobic biofilm and aerobic immobilized bed reactor. The minimal mineral salt (MMS) medium saturated with TCE was pumped at the rate of 1 ml per hour into the anaerobic reactor. The MMS medium saturated with DCE and supplemented with xylenes and toluene (3 ppm each) was pumped at the rate of 1 ml per hour into the fluidized air-uplift-type reactor containing the immobilized aerobic cells. The concentrations of TCE and DCE and the metabolites formed during their degradation by the anaerobic and aerobic cultures were monitored by GC. The preliminary study suggests that the anaerobic and aerobic cultures of our isolates can degrade TCE and DCE.

  1. New Routes for Aerobic Biodegradation of Dimethylsulfoniopropionate

    PubMed Central

    Taylor, Barrie F.; Gilchrist, Darrin C.

    1991-01-01

    Dimethylsulfoniopropionate (DMSP), an osmolyte in marine plants, is biodegraded by cleavage of dimethyl sulfide (DMS) or by demethylation to 3-methiolpropionate (MMPA) and 3-mercaptopropionate (MPA). Sequential demethylation has been observed only with anoxic slurries of coastal sediments. Bacteria that grew aerobically on MMPA and DMSP were isolated from marine environments and phytoplankton cultures. Enrichments with DMSP selected for bacteria that generated DMS, whereas MMPA enrichments selected organisms that produced methanethiol (CH3SH) from either DMSP or MMPA. A bacterium isolated on MMPA grew on MMPA and DMSP, but rapid production of CH3SH from DMSP occurred only with DMSP-grown cells. Low levels of MPA accumulated during growth on MMPA, indicating demethylation as well as demethiolation of MMPA. The alternative routes for DMSP biodegradation via MMPA probably impact on net DMS fluxes to the marine atmosphere. PMID:16348607

  2. Aerobic Glycolysis in Osteoblasts

    PubMed Central

    Esen, Emel; Long, Fanxin

    2014-01-01

    Osteoblasts, the chief bone-making cells in the body, are a focus of osteoporosis research. Although teriparatite, a synthetic fragment of the human parathyroid hormone (PTH), has been an effective bone anabolic drug, there remains a clinical need for additional therapeutics that safely stimulates osteoblast number and function. Work in the past several decades has provided unprecedented clarity about the roles of growth factors and transcription factors in regulating osteoblast differentiation and activity, but whether these factors may regulate cellular metabolism to influence cell fate and function has been largely unexplored. The past few years have witnessed a resurgence of interest in the cellular metabolism of osteoblasts, with the hope that elucidation of their metabolic profile may open new avenues for developing bone anabolic agents. Here we review the current understanding about glucose metabolism in osteoblasts. PMID:25200872

  3. Aerobic scope explains individual variation in feeding capacity

    PubMed Central

    Auer, Sonya K.; Salin, Karine; Anderson, Graeme J.; Metcalfe, Neil B.

    2015-01-01

    Links between metabolism and components of fitness such as growth, reproduction and survival can depend on food availability. A high standard metabolic rate (SMR; baseline energy expenditure) or aerobic scope (AS; the difference between an individual's maximum and SMR) is often beneficial when food is abundant or easily accessible but can be less important or even disadvantageous when food levels decline. While the mechanisms underlying these context-dependent associations are not well understood, they suggest that individuals with a higher SMR or AS are better able to take advantage of high food abundance. Here we show that juvenile brown trout (Salmo trutta) with a higher AS were able to consume more food per day relative to individuals with a lower AS. These results help explain why a high aerobic capacity can improve performance measures such as growth rate at high but not low levels of food availability. PMID:26556902

  4. Aerobic scope explains individual variation in feeding capacity.

    PubMed

    Auer, Sonya K; Salin, Karine; Anderson, Graeme J; Metcalfe, Neil B

    2015-11-01

    Links between metabolism and components of fitness such as growth, reproduction and survival can depend on food availability. A high standard metabolic rate (SMR; baseline energy expenditure) or aerobic scope (AS; the difference between an individual's maximum and SMR) is often beneficial when food is abundant or easily accessible but can be less important or even disadvantageous when food levels decline. While the mechanisms underlying these context-dependent associations are not well understood, they suggest that individuals with a higher SMR or AS are better able to take advantage of high food abundance. Here we show that juvenile brown trout (Salmo trutta) with a higher AS were able to consume more food per day relative to individuals with a lower AS. These results help explain why a high aerobic capacity can improve performance measures such as growth rate at high but not low levels of food availability. PMID:26556902

  5. Upregulation of hepatic bile acid synthesis via fibroblast growth factor 19 is defective in gallstone disease but functional in overweight individuals

    PubMed Central

    Harsch, Simone; Matysik, Silke; Lütjohann, Dieter; Schmitz, Gerd; Stange, Eduard F

    2014-01-01

    Background: Fibroblast growth factor 19 (FGF19) is an enteric hormone regulating bile acid de novo synthesis by sensing ileal bile acid flux. However, the role of FGF19 in cholelithiasis has not yet been elucidated and therefore is investigated in the present study. Methods: Total mRNA and protein were isolated from ileal biopsies and used for tissue expression analysis. FGF19, 7α-hydroxycholesterol (7α-OH-Chol), 27-hydroxycholesterol (27-OH-Chol), and different bile acids were determined in the blood samples. Results: FGF19 serum levels did not differ between gallstone carriers and controls but were significantly decreased in the overweight individuals (−32%, p = 0.0002), irrespective of gallstone status (normalweight to overweight controls −29%, p = 0.0017; normalweight to overweight gallstone carriers −44%, p = 0.0338), and correlated inversely with bodyweight (p < 0.0001, ρ = −0.3317). Compared to non-overweight controls, apical sodium-dependent bile acid transporter expression was significantly diminished in the non-overweight gallstone carriers (−42%, PmRNA = 0.0393; −52%, pprotein = 0.0169) as well as in the overweight controls (−24%, PmRNA = 0.0148; −43%, pprotein = 0.0017). FGF19 expression varied widely and was similar in all groups. A significant negative correlation was noted between 7α-OH-Chol, 27-OH-Chol, and FGF19 serum levels (p < 0.01; ρ7α-OH-Chol = −0.2155; ρ27-OH-Chol = −0.2144) in obesity. Conclusion: Upregulation of hepatic bile acid synthesis via FGF 19 is defective in gallstone disease but functional in overweight individuals. PMID:25360305

  6. WWOX loss activates aerobic glycolysis

    PubMed Central

    Abu-Remaileh, Muhannad; Seewaldt, Victoria L; Aqeilan, Rami I

    2015-01-01

    Cancer cells undergo reprogramming of glucose metabolism to limit energy production to glycolysis—a state known as “aerobic glycolysis.” Hypoxia-inducible factor 1 (HIF1α) is a transcription factor that regulates many genes responsible for this switch. As discussed here, new data suggest that the tumor suppressor WW domain-containing oxidoreductase (WWOX) modulates HIF1α, thereby regulating this metabolic state. PMID:27308416

  7. 1Interaction between serum BDNF and aerobic fitness predicts recognition memory in healthy young adults

    PubMed Central

    Whiteman, Andrew; Young, Daniel E.; He, Xuemei; Chen, Tai C.; Wagenaar, Robert C.; Stern, Chantal; Schon, Karin

    2013-01-01

    Convergent evidence from human and non-human animal studies suggests aerobic exercise and increased aerobic capacity may be beneficial for brain health and cognition. It is thought growth factors may mediate this putative relationship, particularly by augmenting plasticity mechanisms in the hippocampus, a brain region critical for learning and memory. Among these factors, glucocorticoids, brain derived neurotrophic factor (BDNF), insulin-like growth factor-1 (IGF-1), and vascular endothelial growth factor (VEGF), hormones that have considerable and diverse physiological importance, are thought to effect normal and exercise-induced hippocampal plasticity. Despite these predictions, relatively few published human studies have tested hypotheses that relate exercise and fitness to the hippocampus, and none have considered the potential links to all of these hormonal components. Here we present cross-sectional data from a study of recognition memory; serum BDNF, cortisol, IGF-1, and VEGF levels; and aerobic capacity in healthy young adults. We measured circulating levels of these hormones together with performance on a recognition memory task, and a standard graded treadmill test of aerobic fitness. Regression analyses demonstrated BDNF and aerobic fitness predict recognition memory in an interactive manner. In addition, IGF-1 was positively associated with aerobic fitness, but not with recognition memory. Our results may suggest an exercise adaptation-related change in the BDNF dose-response curve that relates to hippocampal memory. PMID:24269495

  8. Methods to determine aerobic endurance.

    PubMed

    Bosquet, Laurent; Léger, Luc; Legros, Patrick

    2002-01-01

    Physiological testing of elite athletes requires the correct identification and assessment of sports-specific underlying factors. It is now recognised that performance in long-distance events is determined by maximal oxygen uptake (V(2 max)), energy cost of exercise and the maximal fractional utilisation of V(2 max) in any realised performance or as a corollary a set percentage of V(2 max) that could be endured as long as possible. This later ability is defined as endurance, and more precisely aerobic endurance, since V(2 max) sets the upper limit of aerobic pathway. It should be distinguished from endurance ability or endurance performance, which are synonymous with performance in long-distance events. The present review examines methods available in the literature to assess aerobic endurance. They are numerous and can be classified into two categories, namely direct and indirect methods. Direct methods bring together all indices that allow either a complete or a partial representation of the power-duration relationship, while indirect methods revolve around the determination of the so-called anaerobic threshold (AT). With regard to direct methods, performance in a series of tests provides a more complete and presumably more valid description of the power-duration relationship than performance in a single test, even if both approaches are well correlated with each other. However, the question remains open to determine which systems model should be employed among the several available in the literature, and how to use them in the prescription of training intensities. As for indirect methods, there is quantitative accumulation of data supporting the utilisation of the AT to assess aerobic endurance and to prescribe training intensities. However, it appears that: there is no unique intensity corresponding to the AT, since criteria available in the literature provide inconsistent results; and the non-invasive determination of the AT using ventilatory and heart rate

  9. Silicon sheet growth development for the large area silicon sheet task of the low cost solar array project. Quantitative analysis of defects in silicon

    NASA Technical Reports Server (NTRS)

    Natesh, R.

    1978-01-01

    The various steps involved in obtaining quantitative information of structural defects in crystalline silicon samples are described. Procedures discussed include: (1) chemical polishing; (2) chemical etching; and (3) automated image analysis of samples on the QTM 720 System.

  10. Characterization of a marine origin aerobic nitrifying-denitrifying bacterium.

    PubMed

    Zheng, Hai-Yan; Liu, Ying; Gao, Xi-Yan; Ai, Guo-Min; Miao, Li-Li; Liu, Zhi-Pei

    2012-07-01

    The bacterial strain F6 was isolated from a biological aerated filter that is used for purifying recirculating water in a marine aquaculture system and was identified as Marinobacter sp. based on the analysis of its 16S rRNA gene sequence. Strain F6 showed efficient aerobic denitrifying ability. One hundred percent of nitrates and 73.10% of nitrites were removed, and the total nitrogen (TN) removal rates reached 50.08% and 33.03% under a high nitrate and nitrite concentration in the medium, respectively. N(2)O and (15)N(2), as revealed by GC-MS and GC-IRMS, were the products of aerobic denitrification. Factors affecting the growth and aerobic denitrifying performance of strain F6 were investigated. The results showed that the optimum aerobic denitrification conditions for strain F6 were the presence of sodium succinate as a carbon source, a C/N ratio of 15, salinity ranging from 32-35 g/L of NaCl, incubation temperature of 30°C, an initial pH of 7.5, and rotation speed of 150 rpm [dissolved oxygen (DO) 6.75 mg/L]. In addition, strain F6 was confirmed to be a heterotrophic nitrifier through its NO(2)(-) generation and 25.96% TN removal when NH(4)(+) was used as the sole N source. Therefore, strain F6, the first reported member of genus Marinobacter with aerobic heterotrophic nitrifying-denitrifying ability, is an excellent candidate for facilitating simultaneous nitrification and denitrification (SND) in industry and aquaculture wastewater. PMID:22578593

  11. Influence of an aniline supplement on the stability of aerobic granular sludge.

    PubMed

    Dai, Yajie; Jiang, Yixin; Su, Haijia

    2015-10-01

    In order to evaluate the stability of aerobic granules in a toxic environment, this study discussed the influence of an aniline supplement on the properties and microbial community of aerobic granules. In the early stages of sequencing batch reactor (SBR) operation, an aniline supplement slightly affected the properties of the aerobic granules (strength, growth rate, SVI and so on). This effect was thereafter removed because of a change in the microbial community and the structure of aerobic granules: with the present of aniline, microbes with biodegradation ability appeared and gathered in the aerobic granules and the aerobic granules densified and settled faster as their SVI decreased to 35 mL/g and settling velocity increased to 41.56 m/h. When a synthetic waste water containing acetate as carbon source was used as influent, aniline (10-500 mg/L) could be degraded in 6 h, at a rate as high as 37.5 mg aniline/(L·h), with a removal rate in excess of 90%, while the effluent COD fell below 100 mg/L from the initial about 2000 mg/L. The aerobic granules cultured by acetate were compact, stable and resistant to aniline. PMID:26233584

  12. Kinetics of aerobic cometabolic biodegradation of chlorinated and brominated aliphatic hydrocarbons: A review.

    PubMed

    Jesus, João; Frascari, Dario; Pozdniakova, Tatiana; Danko, Anthony S

    2016-05-15

    This review analyses kinetic studies of aerobic cometabolism (AC) of halogenated aliphatic hydrocarbons (HAHs) from 2001-2015 in order to (i) compare the different kinetic models proposed, (ii) analyse the estimated model parameters with a focus on novel HAHs and the identification of general trends, and (iii) identify further research needs. The results of this analysis show that aerobic cometabolism can degrade a wide range of HAHs, including HAHs that were not previously tested such as chlorinated propanes, highly chlorinated ethanes and brominated methanes and ethanes. The degree of chlorine mineralization was very high for the chlorinated HAHs. Bromine mineralization was not determined for studies with brominated aliphatics. The examined research period led to the identification of novel growth substrates of potentially high interest. Decreasing performance of aerobic cometabolism were found with increasing chlorination, indicating the high potential of aerobic cometabolism in the presence of medium- and low-halogenated HAHs. Further research is needed for the AC of brominated aliphatic hydrocarbons, the potential for biofilm aerobic cometabolism processes, HAH-HAH mutual inhibition and the identification of the enzymes responsible for each aerobic cometabolism process. Lastly, some indications for a possible standardization of future kinetic studies of HAH aerobic cometabolism are provided. PMID:26874310

  13. Aerobic granular processes: Current research trends.

    PubMed

    Zhang, Quanguo; Hu, Jianjun; Lee, Duu-Jong

    2016-06-01

    Aerobic granules are large biological aggregates with compact interiors that can be used in efficient wastewater treatment. This mini-review presents new researches on the development of aerobic granular processes, extended treatments for complicated pollutants, granulation mechanisms and enhancements of granule stability in long-term operation or storage, and the reuse of waste biomass as renewable resources. A discussion on the challenges of, and prospects for, the commercialization of aerobic granular process is provided. PMID:26873285

  14. Demineralized Bone Matrix Combined Bone Marrow Mesenchymal Stem Cells, Bone Morphogenetic Protein-2 and Transforming Growth Factor-β3 Gene Promoted Pig Cartilage Defect Repair

    PubMed Central

    Wang, Xin; Li, Yanlin; Han, Rui; He, Chuan; Wang, Guoliang; Wang, Jianwei; Zheng, Jiali; Pei, Mei; Wei, Lei

    2014-01-01

    Objectives To investigate whether a combination of demineralized bone matrix (DBM) and bone marrow mesenchymal stem cells (BMSCs) infected with adenovirus-mediated- bone morphogenetic protein (Ad-BMP-2) and transforming growth factor-β3 (Ad-TGF-β3) promotes the repair of the full-thickness cartilage lesions in pig model. Methods BMSCs isolated from pig were cultured and infected with Ad-BMP-2(B group), Ad-TGF-β3 (T group), Ad-BMP-2 + Ad-TGF-β3(BT group), cells infected with empty Ad served as a negative group(N group), the expression of the BMP-2 and TGF-β3 were confirmed by immunofluorescence, PCR, and ELISA, the expression of SOX-9, type II collagen(COL-2A), aggrecan (ACAN) in each group were evaluated by real-time PCR at 1w, 2w, 3w, respectively. The chondrogenic differentiation of BMSCs was evaluated by type II collagen at 21d with immunohistochemical staining. The third-passage BMSCs infected with Ad-BMP-2 and Ad-TGF-β3 were suspended and cultured with DBM for 6 days to construct a new type of tissue engineering scaffold to repair full-thickness cartilage lesions in the femur condyles of pig knee, the regenerated tissue was evaluated at 1,2 and 3 months after surgery by gross appearance, H&E, safranin O staining and O'driscoll score. Results Ad-BMP-2 and Ad-TGF-β3 (BT group) infected cells acquired strong type II collagen staining compared with Ad-BMP-2 (B group) and Ad-TGF-β3 (T group) along. The Ad-BMP-2 and Ad-TGF-β3 infected BMSCs adhered and propagated well in DBM and the new type of tissue engineering scaffold produced hyaline cartilage morphology containing a stronger type II collagen and safranin O staining, the O'driscoll score was higher than other groups. Conclusions The DBM compound with Ad-BMP-2 and Ad-TGF-β3 infected BMSCs scaffold has a good biocompatibility and could well induce cartilage regeneration to repair the defects of joint cartilage. This technology may be efficiently employed for cartilage lesions repair in vivo. PMID

  15. Congenital Defects.

    ERIC Educational Resources Information Center

    Goldman, Allen S.; And Others

    There are two general categories (not necessarily mutually exclusive) of congenital defects: (1) abnormalities that have an hereditary basis, such as single and multiple genes, or chromosomal abberration; and (2) abnormalities that are caused by nonhereditary factors, such as malnutrition, maternal disease, radiation, infections, drugs, or…

  16. Semilocal defects

    SciTech Connect

    Preskill, J. )

    1992-11-15

    I analyze the interplay of gauge and global symmetries in the theory of topological defects. In a two-dimensional model in which both gauge symmetries and {ital exact} global symmetries are spontaneously broken, stable vortices may fail to exist even though magnetic flux is topologically conserved. Following Vachaspati and Achucarro, I formulate the condition that must be satisfied by the pattern of symmetry breakdown for finite-energy configurations to exist in which the conserved magnetic flux is spread out instead of confined to a localized vortex. If this condition is met, vortices are always unstable at sufficiently weak gauge coupling. I also describe the properties of defects in models with an accidental'' symmetry that is partially broken by gauge-boson exchange. In some cases, the spontaneously broken accidental symmetry is not restored inside the core of the defect. Then the structure of the defect can be analyzed using an effective field theory; the details of the physics responsible for the spontaneous symmetry breakdown need not be considered. Examples include domain walls and vortices that are classically unstable, but are stabilized by loop corrections, and magnetic monopoles that have an unusual core structure. Finally, I examine the general theory of the electroweak strings'' that were recently discussed by Vachaspati. These arise only in models with gauge-boson mixing,'' and can always end on magnetic monopoles. Cosmological implications are briefly discussed.

  17. Characteristics of a Novel Aerobic Denitrifying Bacterium, Enterobacter cloacae Strain HNR.

    PubMed

    Guo, Long-Jie; Zhao, Bin; An, Qiang; Tian, Meng

    2016-03-01

    A novel aerobic denitrifier strain HNR, isolated from activated sludge, was identified as Enterobacter cloacae by16S rRNA sequencing analysis. Glucose was considered as the most favorable C-source for strain HNR. The logistic equation well described the bacterial growth, yielding a maximum growth rate (μmax) of 0.283 h(-1) with an initial NO3 (-)-N concentration of 110 mg/L. Almost all NO3 (-)-N was removed aerobically within 30 h with an average removal rate of 4.58 mg N L(-1) h(-1). Nitrogen balance analysis revealed that proximately 70.8 % of NO3 (-)-N was removed as gas products and only 20.7 % was transformed into biomass. GC-MS result indicates that N2 was the end product of aerobic denitrification. The enzyme activities of nitrate reductase and nitrite reductase, which are related to the process of aerobic denitrification, were 0.0688 and 0.0054 U/mg protein, respectively. Thus, the aerobic denitrification of reducing NO3 (-) to N2 by strain HNR was demonstrated. The optimal conditions for nitrate removal were C/N ratio 13, pH value 8, shaking speed 127 rpm and temperature 30 °C. These findings show that E. cloacae strain HNR has a potential application on wastewater treatment to achieve nitrate removal under aerobic conditions. PMID:26573667

  18. Axenic aerobic biofilms inhibit corrosion of copper and aluminum.

    PubMed

    Jayaraman, A; Ornek, D; Duarte, D A; Lee, C C; Mansfeld, F B; Wood, T K

    1999-11-01

    The corrosion behavior of unalloyed copper and aluminum alloy 2024 in modified Baar's medium has been studied with continuous reactors using electrochemical impedance spectroscopy. An axenic aerobic biofilm of either Pseudomonas fragi K or Bacillus brevis 18 was able to lessen corrosion as evidenced by a consistent 20-fold increase in the low-frequency impedance value of copper as well as by a consistent four- to seven-fold increase in the polarization resistance of aluminum 2024 after six days exposure compared to sterile controls. This is the first report of axenic aerobic biofilms inhibiting generalized corrosion of copper and aluminum. Addition of the representative sulfate-reducing bacterium (SRB) Desulfovibrio vulgaris (to simulate consortia corrosion behavior) to either the P. fragi K or B. brevis 18 protective biofilm on copper increased the corrosion to that of the sterile control unless antibiotic (ampicillin) was added to inhibit the growth of SRB in the biofilm. PMID:10616712

  19. Testing Asymmetry in Plasma-Ball Growth Seeded by a Nanoscale Absorbing Defect Embedded in a SiO2 Thin-Film Matrix Subjected to UV Pulsed-Laser Radiation

    SciTech Connect

    Papernov, S.; Schmid, A.W.

    2008-09-16

    Previous studies of ultraviolet, nanosecond-pulsed-laser damage in thin films revealed nanoscale absorbing defects as a major source of damage initiation. It was also demonstrated that damage (crater formation) is facilitated by plasma-ball formation around absorbing defects. In this work an attempt is made to verify the symmetry of the plasma ball by irradiating SiO2 thin film with embedded gold nanoparticles from the side of either the air/film or substrate/film interfaces. Crater-formation thresholds derived in each case support preferential plasma-ball growth in the direction of the laser-beam source. The strong impact of internal E-field distribution is identified.

  20. Testing asymmetry in plasma-ball growth seeded by a nanoscale absorbing defect embedded in a SiO{sub 2} thin-film matrix subjected to UV pulsed-laser radiation

    SciTech Connect

    Papernov, S.; Schmid, A. W.

    2008-09-15

    Previous studies of ultraviolet, nanosecond-pulsed-laser damage in thin films revealed nanoscale absorbing defects as a major source of damage initiation. It was also demonstrated that damage (crater formation) is facilitated by plasma-ball formation around absorbing defects. In this work an attempt is made to verify the symmetry of the plasma ball by irradiating SiO{sub 2} thin film with embedded gold nanoparticles from the side of either the air/film or substrate/film interfaces. Crater-formation thresholds derived in each case support preferential plasma-ball growth in the direction of the laser-beam source. The strong impact of internal E-field distribution is identified.

  1. Aerobic Fitness for the Moderately Retarded.

    ERIC Educational Resources Information Center

    Bauer, Dan

    1981-01-01

    Intended for physical education teachers, the booklet offers ideas for incorporating aerobic conditioning into programs for moderately mentally retarded students. An explanation of aerobic fitness and its benefits is followed by information on initiating a fitness program with evaluation of height, weight, body fat, resting heart rate, and…

  2. Aerobic rice mechanization: techniques for crop establishment

    NASA Astrophysics Data System (ADS)

    Khusairy, K. M.; Ayob, H.; Chan, C. S.; Fauzi, M. I. Mohamed; Mohamad Fakhrul, Z. O.; Shahril Shah, G. S. M.; Azlan, O.; Rasad, M. A.; Hashim, A. M.; Arshad, Z.; E, E. Ibrahim; Saifulizan, M. N.

    2015-12-01

    Rice being the staple food crops, hundreds of land races in it makes the diversity of rice crops. Aerobic rice production was introduced which requires much less water input to safeguard and sustain the rice production and conserve water due to decreasing water resources, climatic changes and competition from urban and industrial users. Mechanization system plays an important role for the success of aerobic rice cultivation. All farming activities for aerobic rice production are run on aerobic soil conditions. Row seeder mechanization system is developed to replace conventional seeding technique on the aerobic rice field. It is targeted for small and the large scale aerobic rice farmers. The aero - seeder machine is used for the small scale aerobic rice field, while the accord - seeder is used for the large scale aerobic rice field. The use of this mechanization machine can eliminate the tedious and inaccurate seeding operations reduce labour costs and increases work rate. The machine is easy to operate and it can increase crop establishment rate. It reduce missing hill, increasing planting and crop with high yield can be produce. This machine is designed for low costs maintenance and it is easy to dismantle and assemble during maintenance and it is safe to be used.

  3. Skeletal Muscle Hypertrophy after Aerobic Exercise Training

    PubMed Central

    Konopka, Adam R.; Harber, Matthew P.

    2014-01-01

    Current dogma suggests aerobic exercise training has minimal effect on skeletal muscle size. We and others have demonstrated that aerobic exercise acutely and chronically alters protein metabolism and induces skeletal muscle hypertrophy. These findings promote an antithesis to the status quo by providing novel perspective on skeletal muscle mass regulation and insight into exercise-countermeasures for populations prone to muscle loss. PMID:24508740

  4. Aerobic Dancing--A Rhythmic Sport.

    ERIC Educational Resources Information Center

    Sorensen, Jacki

    Fitness programs now and in the future must offer built-in cardiovascular conditioning, variety, novelty, and change to meet the physical, mental, and emotional needs of our society. Aerobic dancing (dancing designed to train and strengthen the heart, lungs, and vascular system) is one of the first indoor group Aerobic exercise programs designed…

  5. Defects in flexoelectric solids

    NASA Astrophysics Data System (ADS)

    Mao, Sheng; Purohit, Prashant K.

    2015-11-01

    A solid is said to be flexoelectric when it polarizes in proportion to strain gradients. Since strain gradients are large near defects, we expect the flexoelectric effect to be prominent there and decay away at distances much larger than a flexoelectric length scale. Here, we quantify this expectation by computing displacement, stress and polarization fields near defects in flexoelectric solids. For point defects we recover some well known results from strain gradient elasticity and non-local piezoelectric theories, but with different length scales in the final expressions. For edge dislocations we show that the electric potential is a maximum in the vicinity of the dislocation core. We also estimate the polarized line charge density of an edge dislocation in an isotropic flexoelectric solid which is in agreement with some measurements in ice. We perform an asymptotic analysis of the crack tip fields in flexoelectric solids and show that our results share some features from solutions in strain gradient elasticity and piezoelectricity. We also compute the energy release rate for cracks using simple crack face boundary conditions and use them in classical criteria for crack growth to make predictions. Our analysis can serve as a starting point for more sophisticated analytic and computational treatments of defects in flexoelectric solids which are gaining increasing prominence in the field of nanoscience and nanotechnology.

  6. Effects of natural and synthetic auxins on the gravitropic growth habit of roots in two auxin-resistant mutants of Arabidopsis, axr1 and axr4: evidence for defects in the auxin influx mechanism of axr4

    NASA Technical Reports Server (NTRS)

    Yamamoto, M.; Yamamoto, K. T.

    1999-01-01

    The partially agravitropic growth habit of roots of an auxin-resistant mutant of Arabidopsis thaliana, axr4, was restored by the addition of 30-300 nM 1-naphthaleneacetic acid (NAA) to the growth medium. Neither indole 3-acetic acid (IAA) nor 2,4-dichlorophenoxyacetic acid (2,4-D) showed such an effect. Growth of axr4 roots was resistant to IAA and 2,4-D, but not at all to NAA. The differential effects of the three auxins suggest that the defects of axr4 result from a lower auxin influx into its cells. The partially agravitropic growth habit of axr1 roots, which was less severe than that of axr4 roots, was only slightly affected by the three auxins in the growth medium at concentrations up to 300 nM; growth of axr1 roots was resistant to all three of the auxins. These results suggest that the lesion of axrl mutants is different from that of axr4.

  7. Respirometric assessment of aerobic sludge stabilization.

    PubMed

    Tas, Didem Okutman

    2010-04-01

    Aerobic sludge stabilization was assessed respirometrically with the sludge taken from the secondary settling tank of a domestic wastewater treatment facility in Istanbul, Turkey. Zero-order removal rates of 178, 127 and 44 mg/L day were found for Suspended Solids (SS), Volatile Suspended Solids (VSS) and Total Organic Carbon (TOC) at the end of 18 days sludge stabilization, respectively. Significant nutrient release was observed by the mineralized nitrogen and phosphorus from the death and lysis of microorganisms. The model simulations for the batch respirometric assays for initial, 7th and 18th days of the stabilization agree reasonably well with the experimental data. The maximum storage rates (k(sto)) as well as maximum growth rates on stored products (micro(H2)) decrease with increasing stabilization period. Respirometric assays indicated the presence of microorganisms that started to compete with the dominant microorganisms as a result of the stabilization. As such, these findings have significance in terms of the efforts related to the sludge management and application processes. PMID:19942430

  8. Soil and sediment bacteria capable of aerobic nitrate respiration.

    PubMed Central

    Carter, J P; Hsaio, Y H; Spiro, S; Richardson, D J

    1995-01-01

    Several laboratory strains of gram-negative bacteria are known to be able to respire nitrate in the presence of oxygen, although the physiological advantage gained from this process is not entirely clear. The contribution that aerobic nitrate respiration makes to the environmental nitrogen cycle has not been studied. As a first step in addressing this question, a strategy which allows for the isolation of organisms capable of reducing nitrate to nitrite following aerobic growth has been developed. Twenty-nine such strains have been isolated from three soils and a freshwater sediment and shown to comprise members of three genera (Pseudomonas, Aeromonas, and Moraxella). All of these strains expressed a nitrate reductase with an active site located in the periplasmic compartment. Twenty-two of the strains showed significant rates of nitrate respiration in the presence of oxygen when assayed with physiological electron donors. Also isolated was one member of the gram-positive genus Arthrobacter, which was likewise able to respire nitrate in the presence of oxygen but appeared to express a different type of nitrate reductase. In the four environments studied, culturable bacteria capable of aerobic nitrate respiration were isolated in significant numbers (10(4) to 10(7) per g of soil or sediment) and in three cases were as abundant as, or more abundant than, culturable bacteria capable of denitrification. Thus, it seems likely that the corespiration of nitrate and oxygen may indeed make a significant contribution to the flux of nitrate to nitrite in the environment. PMID:7487017

  9. Evaluation of an aerobic treatment for olive mill wastewater detoxification.

    PubMed

    El Hajjouji, Houda; El Fels, Loubna; Pinelli, Eric; Barje, Farid; El Asli, Abdelghani; Merlina, Georges; Hafidi, Mohamed

    2014-01-01

    Olive mill wastewater (OMWW) is a by-product of the olive oil extraction industry. Its dumping creates severe environmental problems in the Mediterranean countries. The phytoxicity of OMWW is due to the phenolic substances and is evaluated through a genotoxicity method. An aerobic treatment of OMWW was conducted during 45 days. Different concentrations of raw and treated OMWW were tested using the Vicia faba micronuclei test. Results showed that raw OMWW induced significant micronuclei formation at 10% of OMWW dilution. At 20% of dilution, no mitosis was recorded. The 45 days aerobic treatment OMWW showed an important decrease in the genotoxicity and also in the toxicity that was observed at 10% and 20% OMWW dilution. This could be correlated with the biodegradation of 76% of the total phenols. Indeed, qualitative analysis by high performance liquid chromatography shows the disappearance of the majority of phenolic compounds after 45 days of treatment. This study was completed by an agricultural test with V. faba plant. Data showed significant growth yield of 36.3% and 29.9% after being irrigated with 5 and 10 t/ha, respectively. These results supported the positive role of aerobic treatment on OMWW and their capacity to ameliorate the agronomic potential of these effluents. PMID:25244133

  10. Fit women are not able to use the whole aerobic capacity during aerobic dance.

    PubMed

    Edvardsen, Elisabeth; Ingjer, Frank; Bø, Kari

    2011-12-01

    Edvardsen, E, Ingjer, F, and Bø, K. Fit women are not able to use the whole aerobic capacity during aerobic dance. J Strength Cond Res 25(12): 3479-3485, 2011-This study compared the aerobic capacity during maximal aerobic dance and treadmill running in fit women. Thirteen well-trained female aerobic dance instructors aged 30 ± 8.17 years (mean ± SD) exercised to exhaustion by running on a treadmill for measurement of maximal oxygen uptake (VO(2)max) and peak heart rate (HRpeak). Additionally, all subjects performed aerobic dancing until exhaustion after a choreographed videotaped routine trying to reach the same HRpeak as during maximal running. The p value for statistical significance between running and aerobic dance was set to ≤0.05. The results (mean ± SD) showed a lower VO(2)max in aerobic dance (52.2 ± 4.02 ml·kg·min) compared with treadmill running (55.9 ± 5.03 ml·kg·min) (p = 0.0003). Further, the mean ± SD HRpeak was 182 ± 9.15 b·min in aerobic dance and 192 ± 9.62 b·min in treadmill running, giving no difference in oxygen pulse between the 2 exercise forms (p = 0.32). There was no difference in peak ventilation (aerobic dance: 108 ± 10.81 L·min vs. running: 113 ± 11.49 L·min). In conclusion, aerobic dance does not seem to be able to use the whole aerobic capacity as in running. For well endurance-trained women, this may result in a lower total workload at maximal intensities. Aerobic dance may therefore not be as suitable as running during maximal intensities in well-trained females. PMID:22080322

  11. Roles of triosephosphate isomerase and aerobic metabolism in Trypanosoma brucei.

    PubMed Central

    Helfert, S; Estévez, A M; Bakker, B; Michels, P; Clayton, C

    2001-01-01

    Kinetoplastid protozoa compartmentalize the first seven enzymes of glycolysis and two enzymes of glycerol metabolism in a microbody, the glycosome. While in its mammalian host, Trypanosoma brucei depends entirely on glucose for ATP generation. Under aerobic conditions, most of the glucose is metabolized to pyruvate. Aerobic metabolism depends on the activities of glycosomal triosephosphate isomerase and a mitochondrial glycerophosphate oxidase, and on glycerophosphate<-->dihydroxyacetone phosphate exchange across the glycosomal membrane. Using a combination of genetics and computer modelling, we show that triosephosphate isomerase is probably essential for bloodstream trypanosome survival, but not for the insect-dwelling procyclics, which preferentially use amino acids as an energy source. When the enzyme level decreased to about 15% of that of the wild-type, the growth rate was halved. Below this level, a lethal rise in dihydroxyacetone phosphate was predicted. Expression of cytosolic triosephosphate isomerase inhibited cell growth. Attempts to knockout the trypanosome alternative oxidase genes (which are needed for glycerophosphate oxidase activity) were unsuccessful, but when we lowered the level of the corresponding mRNA by expressing a homologous double-stranded RNA, oxygen consumption was reduced fourfold and the rate of trypanosome growth was halved. PMID:11415442

  12. Improved Aerobic Colony Count Technique for Hydrophobic Grid Membrane Filters

    PubMed Central

    Parrington, Lorna J.; Sharpe, Anthony N.; Peterkin, Pearl I.

    1993-01-01

    The AOAC International official action procedure for performing aerobic colony counts on hydrophobic grid membrane filters (HGMFs) uses Trypticase soy-fast green FCF agar (FGA) incubated for 48 h. Microbial growths are various shades of green on a pale green background, which can cause problems for automated as well as manual counting. HGMFs which had been incubated 24 or 48 h at 35°C on Trypticase soy agar were flooded underneath with 1 to 2 ml of 0.1% triphenyltetrazolium chloride (TTC) solution by simply lifting one corner of the filter while it was still on the agar and adding the reagent. Microbial growths on HGMFs were counted after color had been allowed to develop for 15 min at room temperature. With representative foods, virtually all colonies stained pink to red. Automated electronic counts made by using the MI-100 HGMF Interpreter were easier and more reliable than control HGMF counts made by the AOAC International official action procedure. Manual counting was easier as well because of increased visibility of the microbial growths. Except in the case of dairy products, 24-h TTC counts did not differ significantly from 48-h FGA counts, whereas the FGA counts at 24 h were always significantly lower, indicating that for many food products the HGMF TTC flooding method permits aerobic colony counts to be made after 24 h. PMID:16349033

  13. Chemotactic Motility of Pseudomonas fluorescens F113 under Aerobic and Denitrification Conditions

    PubMed Central

    Redondo-Nieto, Miguel; Rivilla, Rafael; Martín, Marta

    2015-01-01

    The sequence of the genome of Pseudomonas fluorescens F113 has shown the presence of multiple traits relevant for rhizosphere colonization and plant growth promotion. Among these traits are denitrification and chemotactic motility. Besides aerobic growth, F113 is able to grow anaerobically using nitrate and nitrite as final electron acceptors. F113 is able to perform swimming motility under aerobic conditions and under anaerobic conditions when nitrate is used as the electron acceptor. However, nitrite can not support swimming motility. Regulation of swimming motility is similar under aerobic and anaerobic conditions, since mutants that are hypermotile under aerobic conditions, such as gacS, sadB, kinB, algU and wspR, are also hypermotile under anaerobic conditions. However, chemotactic behavior is different under aerobic and denitrification conditions. Unlike most pseudomonads, the F113 genome encode three complete chemotaxis systems, Che1, Che2 and Che3. Mutations in each of the cheA genes of the three Che systems has shown that the three systems are functional and independent. Mutation of the cheA1 gene completely abolished swimming motility both under aerobic and denitrification conditions. Mutation of the cheA2 gene, showed only a decrease in swimming motility under both conditions, indicating that this system is not essential for chemotactic motility but is necessary for optimal motility. Mutation of the cheA3 gene abolished motility under denitrification conditions but only produced a decrease in motility under aerobic conditions. The three Che systems proved to be implicated in competitive rhizosphere colonization, being the cheA1 mutant the most affected. PMID:26161531

  14. Stabilized homoserine o-succinyltransferases (MetA) or L-methionine partially recovers the growth defect in Escherichia coli lacking ATP-dependent proteases or the DnaK chaperone

    PubMed Central

    2013-01-01

    Background The growth of Escherichia coli at elevated temperatures is limited due to the inherent instability of homoserine o-succinyltransferase, MetA, which is the first enzyme in the methionine biosynthesis pathway. MetA is also unstable under other stressful conditions, such as weak organic acids and oxidative stress. The MetA protein unfolds, even at 25°C, forms considerable aggregates at 37°C and completely aggregates at 44°C. Results We extended the MetA mutation studies using a consensus concept based on statistics and sequence database analysis to predict the point mutations resulting in increased MetA stability. In this study, four single amino acid substitutions (Q96K, I124L, I229Y and F247Y) in MetA designed according to the consensus concept and using the I-mutant2.0 modeling tool conferred accelerated growth on the E. coli strain WE at 44°C. MetA mutants that enabled E. coli growth at higher temperatures did not display increased melting temperatures (Tm) or enhanced catalytic activity but did show improved in vivo stability at mild (37°C) and elevated (44°C) temperatures. Notably, we observed that the stabilized MetA mutants partially recovered the growth defects of E. coli mutants in which ATP-dependent proteases or the DnaK chaperone was deleted. These results suggest that the impaired growth of these E. coli mutants primarily reflect the inherent instability of MetA and, thus, the methionine supply. As further evidence, the addition of methionine recovered most of the growth defects in mutants lacking either ATP-dependent proteases or the DnaK chaperone. Conclusions A collection of stable single-residue mutated MetA enzymes were constructed and investigated as background for engineering the stabilized mutants. In summary, the mutations in a single gene, metA, reframe the window of growth temperature in both normal and mutant E. coli strains. PMID:23898868

  15. 2010 Defects in Semiconductors GRC

    SciTech Connect

    Shengbai Zhang

    2011-01-06

    Continuing its tradition of excellence, this Gordon Conference will focus on research at the forefront of the field of defects in semiconductors. The conference will have a strong emphasis on the control of defects during growth and processing, as well as an emphasis on the development of novel defect detection methods and first-principles defect theories. Electronic, magnetic, and optical properties of bulk, thin film, and nanoscale semiconductors will be discussed in detail. In contrast to many conferences, which tend to focus on specific semiconductors, this conference will deal with point and extended defects in a broad range of electronic materials. This approach has proved to be extremely fruitful for advancing fundamental understanding in emerging materials such as wide-band-gap semiconductors, oxides, sp{sup 2} carbon based-materials, and photovoltaic/solar cell materials, and in understanding important defect phenomena such as doping bottleneck in nanostructures and the diffusion of defects and impurities. The program consists of about twenty invited talks and a number of contributed poster sessions. The emphasis should be on work which has yet to be published. The large amount of discussion time provides an ideal forum for dealing with topics that are new and/or controversial.

  16. Serine biosynthesis and transport defects.

    PubMed

    El-Hattab, Ayman W

    2016-07-01

    l-serine is a non-essential amino acid that is biosynthesized via the enzymes phosphoglycerate dehydrogenase (PGDH), phosphoserine aminotransferase (PSAT), and phosphoserine phosphatase (PSP). Besides its role in protein synthesis, l-serine is a potent neurotrophic factor and a precursor of a number of essential compounds including phosphatidylserine, sphingomyelin, glycine, and d-serine. Serine biosynthesis defects result from impairments of PGDH, PSAT, or PSP leading to systemic serine deficiency. Serine biosynthesis defects present in a broad phenotypic spectrum that includes, at the severe end, Neu-Laxova syndrome, a lethal multiple congenital anomaly disease, intermediately, infantile serine biosynthesis defects with severe neurological manifestations and growth deficiency, and at the mild end, the childhood disease with intellectual disability. A serine transport defect resulting from deficiency of the ASCT1, the main transporter for serine in the central nervous system, has been recently described in children with neurological manifestations that overlap with those observed in serine biosynthesis defects. l-serine therapy may be beneficial in preventing or ameliorating symptoms in serine biosynthesis and transport defects, if started before neurological damage occurs. Herein, we review serine metabolism and transport, the clinical, biochemical, and molecular aspects of serine biosynthesis and transport defects, the mechanisms of these diseases, and the potential role of serine therapy. PMID:27161889

  17. The Energetics of Aerobic versus Anaerobic Respiration.

    ERIC Educational Resources Information Center

    Champion, Timothy D.; Schwenz, Richard W.

    1990-01-01

    Background information, laboratory procedures, and a discussion of the results of an experiment designed to investigate the difference in energy gained from the aerobic and anaerobic oxidation of glucose are presented. Sample experimental and calculated data are included. (CW)

  18. Neuromodulation of Aerobic Exercise—A Review

    PubMed Central

    Heijnen, Saskia; Hommel, Bernhard; Kibele, Armin; Colzato, Lorenza S.

    2016-01-01

    Running, and aerobic exercise in general, is a physical activity that increasingly many people engage in but that also has become popular as a topic for scientific research. Here we review the available studies investigating whether and to which degree aerobic exercise modulates hormones, amino acids, and neurotransmitters levels. In general, it seems that factors such as genes, gender, training status, and hormonal status need to be taken into account to gain a better understanding of the neuromodular underpinnings of aerobic exercise. More research using longitudinal studies and considering individual differences is necessary to determine actual benefits. We suggest that, in order to succeed, aerobic exercise programs should include optimal periodization, prevent overtraining and be tailored to interindividual differences, including neuro-developmental and genetically-based factors. PMID:26779053

  19. Aerobic Dance for Children: Resources and Recommendations.

    ERIC Educational Resources Information Center

    Wood, Denise A.

    1986-01-01

    Aerobic dance classes may be safe for older children, but are inappropriate for children in the fourth grade and under. Programs for these children should emphasize creativity. Resources for program development are given. (MT)

  20. Conditioning and Aerobics for Older Americans.

    ERIC Educational Resources Information Center

    Hansen, Joyce

    1980-01-01

    A class designed for the maintenance and gradual improvement of senior citizens' physical fitness includes relaxation training, flexibility and stretching exercises, interval training activities (designed as a link between less strenuous exercise and more strenuous activities), and aerobic exercises. (CJ)

  1. Aerobic dynamic feeding as a strategy for in situ accumulation of polyhydroxyalkanoate in aerobic granules.

    PubMed

    Gobi, K; Vadivelu, V M

    2014-06-01

    Aerobic dynamic feeding (ADF) strategy was applied in sequencing batch reactor (SBR) to accumulate polyhydroxyalkanoate (PHA) in aerobic granules. The aerobic granules were able to remove 90% of the COD from palm oil mill effluent (POME). The volatile fatty acids (VFAs) in the POME are the sole source of the PHA accumulation. In this work, 100% removal of propionic and butyric acids in the POME were observed. The highest amount of PHA produced in aerobic granules was 0.6833mgPHA/mgbiomass. The PHA formed was identified as a P (hydroxybutyrate-co-hydroxyvalerate) P (HB-co-HV). PMID:24725384

  2. Physiological responses during aerobic dance of individuals grouped by aerobic capacity and dance experience.

    PubMed

    Thomsen, D; Ballor, D L

    1991-03-01

    This study examined the effects of aerobic capacity (peak oxygen uptake) and aerobic dance experience on the physiological responses to an aerobic dance routine. The heart rate (HR) and VO2 responses to three levels (intensities) of aerobic dance were measured in 27 women. Experienced aerobic dancers (AD) (mean peak VO2 = 42 ml.kg-1.min-1) were compared to subjects with limited aerobic dance experience of high (HI) (peak VO2 greater than 35 ml.kg-1.min-1) and low (LO) (peak VO2 less than 35 ml.kg-1.min-1) aerobic capacities. The results indicated the LO group exercised at a higher percentage of peak heart rate and peak VO2 at all three dance levels than did either the HI or AD groups (HI = AD). Design of aerobic dance routines must consider the exercise tolerance of the intended audience. In mixed groups, individuals with low aerobic capacities should be shown how and encouraged to modify the activity to reduce the level of exertion. PMID:2028095

  3. Comparison of fumerate-pyruvate media and beef extract media for aerobically culturing Campylobacter species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Media supplemented with fumarate, pyruvate, and a vitamin-mineral solution or with beef extract were compared for the ability to support aerobic growth of Campylobacter. Basal broth composed of tryptose, yeast extract, bicarbonate, and agar was supplemented with 30 mM fumarate, 100 mM pyruvate, and ...

  4. Inhibition of Salmonella Typhimurium by Cultures of Cecal Bacteria during Aerobic Incubation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two trials were conducted to examine the ability of cecal bacterial cultures from broilers to inhibit growth of Salmonella Typhimurium during aerobic incubation. Cecal broth media was inoculated with 10 µl of cecal contents from 6 week old broilers taken from 2 separate flocks. Cultures were incubat...

  5. Processed-induced defects in EFG ribbons

    NASA Technical Reports Server (NTRS)

    Cunningham, B.; Ast, D. G.

    1982-01-01

    The defect structure of processed edge defined film-fed growth (EFG) silicon ribbons was studied using a variety of electron microscopic techniques. Comparison between the present results and previous studies on as-grown ribbons has shown that solar cell processing introduces additional defects into the ribbons. The creation of point defects during high temperature phosphorus diffusion induces dislocation climb, resulting in the formation of dislocation helices in the diffused layer.

  6. An overview of hgcdte mbe defects and analysis of defect size

    NASA Astrophysics Data System (ADS)

    Olsson, Kurt Robert

    HgCdTe is the most widely used material for high performance infrared detection applications. Growth of HgCdTe epitaxial layers by molecular beam epitaxy (MBE) has ushered in advanced devices that take advantage of the unique properties of the material. Formation of defects during the growth process is one of the largest drawbacks to this technology, and must be minimized to increase device operability. In this paper, the defects encountered in HgCdTe are categorized, along with formation mechanisms and possible means of reduction. A new method of defect identification is proposed, which takes advantage of full wafer defect mapping capabilities. A correlation between the thickness of the grown film and the size of defects initiated at the substrate surface is found. This allows further defect information to be extracted from the size and density of the defects.

  7. The role of growth atmosphere on the structural and optical quality of defect free ZnO films for strong ultraviolet emission

    NASA Astrophysics Data System (ADS)

    Kumar, Vinod; Swart, H. C.; Som, S.; Kumar, Vijay; Yousif, A.; Pandey, Anurag; Shaat, S. K. K.; Ntwaeaborwa, O. M.

    2014-10-01

    Highly c-axis oriented wurtzite structured ZnO thin films were deposited on silicon substrates using pulsed laser deposition (PLD) by ablating a ZnO target in different atmospheres, including vacuum, argon and oxygen in the deposition chamber. The stress in the films was shown to vary from -3.83 to -0.03 GPa as a function of the chamber atmosphere. The minimum compressive stress (-0.03 GPa) was observed for the oxygen atmosphere. X-ray photoelectron spectroscopy data indicated that the O1s peak consists of three components designated as O1 (due to ZnO), O2 (due to defects) and O3 (due to adsorbed species). A small defect level emission was obtained in the luminescence spectra of the ZnO film deposited in the oxygen atmosphere, while strong ultraviolet (UV) emission was observed for the ZnO films deposited in the vacuum and argon atmosphere. These PLD grown ZnO thin films have the potential to be used as sources of UV radiation in light emitting devices.

  8. Analyzing the impact of ISO on digital imager defects with an automatic defect trace algorithm

    NASA Astrophysics Data System (ADS)

    Leung, Jenny; Chapman, Glenn H.; Choi, Yong H.; Thomas, Rohit; Koren, Israel; Koren, Zahava

    2010-01-01

    Reliability of image sensors is limited by the continuous development of in-field defects. Laboratory calibration on 21 DSLRs has revealed hot pixels as the main defect type found in all tested cameras, with 78% of the identified defects having a time-independent offset. The expanded ISO range that exists in new cameras enables natural light photography. However, the gain applied to all pixels also enhances the appearance of defects. Analysis of defects at varying ISO levels shows that compared to the number of defects at ISO 400, the number of defects at ISO 1600 is 2-3 times higher. Amplifying the defect parameters helps differentiate faults from noise, thus detecting larger defect sets and causes some hot pixels to become saturated. The distribution of defect parameters at various ISO levels shows that the gain applied to faults with moderate defect magnitude caused 2-10% of the defects to saturate at short exposure times (0.03-0.5s). With our expanded defect collection, spatial analysis confirmed the uniform distribution of defects, indicating a random defect source. In our extended study, the temporal growth of defects is analyzed using our defecttracing algorithm. We introduce an improved defect model which incorporates the ISO gain, allowing the detection of defects even in short exposure images at high ISO and thus providing a wider selection of historical images and more accurate defect tracing. Larger area sensors show more hot pixels, while hot pixel rates strongly grow as the pixel size decreases to 2.2 microns.

  9. Growth mechanism and microstructure of low defect density InN (0001) In-face thin films on Si (111) substrates

    SciTech Connect

    Kehagias, Th.; Dimitrakopulos, G. P.; Koukoula, T.; Komninou, Ph.; Ajagunna, A. O.; Georgakilas, A.; Tsagaraki, K.; Adikimenakis, A.

    2013-10-28

    Transmission electron microscopy has been employed to analyze the direct nucleation and growth, by plasma-assisted molecular beam epitaxy, of high quality InN (0001) In-face thin films on (111) Si substrates. Critical steps of the heteroepitaxial growth process are InN nucleation at low substrate temperature under excessively high N-flux conditions and subsequent growth of the main InN epilayer at the optimum conditions, namely, substrate temperature 400–450 °C and In/N flux ratio close to 1. InN nucleation occurs in the form of a very high density of three dimensional (3D) islands, which coalesce very fast into a low surface roughness InN film. The reduced reactivity of Si at low temperature and its fast coverage by InN limit the amount of unintentional Si nitridation by the excessively high nitrogen flux and good bonding/adhesion of the InN film directly on the Si substrate is achieved. The subsequent overgrowth of the main InN epilayer, in a layer-by-layer growth mode that enhances the lateral growth of InN, reduces significantly the crystal mosaicity and the density of threading dislocations is about an order of magnitude less compared to InN films grown using an AlN/GaN intermediate nucleation/buffer layer on Si. The InN films exhibit the In-face polarity and very smooth atomically stepped surfaces.

  10. Biotechnology for aerobic conversion of food waste into organic fertilizer.

    PubMed

    Stabnikova, Olena; Ding, Hong-Bo; Tay, Joo-Hwa; Wang, Jing-Yuan

    2005-02-01

    A biotechnology for aerobic conversion of food waste into organic fertilizer under controlled aeration, stirring, pH and temperature at 55-65 degrees C, is proposed. To maintain neutral pH at the beginning of the bioconversion 5% CaCO3 was added to the total solids of the food waste. The addition of 20% horticultural waste compost as a bulking agent to the food wastes (w.w./w.w.), improved the bioconversion and increased the stability of the final product. No starter culture was needed for aerobic bioconversion of food waste into organic fertilizer for 10 days. The low contents of heavy metals in the raw materials used in the bioconversions ensured the safety of fertilizer from food waste for application in agriculture. The addition of 4% organic fertilizer to the subsoil increased the yield and growth of Ipomoea aquatica (Kang Kong) by 1.5 to 2 times. The addition of phosphorus is required to enhance the positive effect of organic fertilizer on plant growth. PMID:15751394

  11. Beneficial defects: exploiting the intrinsic polishing-induced wafer roughness for the catalyst-free growth of Ge in-plane nanowires

    PubMed Central

    2014-01-01

    We outline a metal-free fabrication route of in-plane Ge nanowires on Ge(001) substrates. By positively exploiting the polishing-induced defects of standard-quality commercial Ge(001) wafers, micrometer-length wires are grown by physical vapor deposition in ultra-high-vacuum environment. The shape of the wires can be tailored by the epitaxial strain induced by subsequent Si deposition, determining a progressive transformation of the wires in SiGe faceted quantum dots. This shape transition is described by finite element simulations of continuous elasticity and gives hints on the equilibrium shape of nanocrystals in the presence of tensile epitaxial strain. PACS 81.07.Gf; 68.35.bg; 68.35.bj; 62.23.Eg PMID:25114649

  12. Taxonomy of Aerobic Marine Eubacteria

    PubMed Central

    Baumann, Linda; Baumann, Paul; Mandel, M.; Allen, Richard D.

    1972-01-01

    Two hundred and eighteen strains of nonfermentative marine bacteria were submitted to an extensive morphological, physiological, and nutritional characterization. All the strains were gram-negative, straight or curved rods which were motile by means of polar or peritrichous flagella. A wide variety of organic substrates served as sole sources of carbon and energy. The strains differed extensively in their nutritional versatility, being able to utilize from 11 to 85 carbon compounds. Some strains had an extracellular amylase, gelatinase, lipase, or chitinase and were able to utilize n-hexadecane and to denitrify. None of the strains had a yellow, cell-associated pigment or a constitutive arginine dihydrolase system, nor were they able to hydrolyze cellulose or agar. The results of the physiological and nutritional characterization were submitted to a numerical analysis which clustered the strains into 22 groups on the basis of phenotypic similarities. The majority of these groups were separable by a large number of unrelated phenotypic traits. Analysis of the moles per cent guanine plus cytosine (GC) content in the deoxyribonucleic acid of representative strains indicated that the peritrichously flagellated groups had a GC content of 53.7 to 67.8 moles%; polarly flagellated strains had a GC content of 30.5 to 64.7 moles%. The peritrichously flagellated groups were assigned to the genus Alcaligenes. The polarly flagellated groups, which had a GC content of 43.2 to 48.0 moles%, were placed into a newly created genus, Alteromonas; groups which had a GC content of 57.8 to 64.7 moles% were placed into the genus Pseudomonas; and the remaining groups were left unassigned. Twelve groups were given the following designations: Alteromonas communis, A. vaga, A. macleodii, A. marinopraesens, Pseudomonas doudoroffi, P. marina, P. nautica, Alcaligenes pacificus, A. cupidus, A. venustus, and A. aestus. The problems of assigning species of aerobic marine bacteria to genera are

  13. Taxonomy of aerobic marine eubacteria.

    PubMed

    Baumann, L; Baumann, P; Mandel, M; Allen, R D

    1972-04-01

    Two hundred and eighteen strains of nonfermentative marine bacteria were submitted to an extensive morphological, physiological, and nutritional characterization. All the strains were gram-negative, straight or curved rods which were motile by means of polar or peritrichous flagella. A wide variety of organic substrates served as sole sources of carbon and energy. The strains differed extensively in their nutritional versatility, being able to utilize from 11 to 85 carbon compounds. Some strains had an extracellular amylase, gelatinase, lipase, or chitinase and were able to utilize n-hexadecane and to denitrify. None of the strains had a yellow, cell-associated pigment or a constitutive arginine dihydrolase system, nor were they able to hydrolyze cellulose or agar. The results of the physiological and nutritional characterization were submitted to a numerical analysis which clustered the strains into 22 groups on the basis of phenotypic similarities. The majority of these groups were separable by a large number of unrelated phenotypic traits. Analysis of the moles per cent guanine plus cytosine (GC) content in the deoxyribonucleic acid of representative strains indicated that the peritrichously flagellated groups had a GC content of 53.7 to 67.8 moles%; polarly flagellated strains had a GC content of 30.5 to 64.7 moles%. The peritrichously flagellated groups were assigned to the genus Alcaligenes. The polarly flagellated groups, which had a GC content of 43.2 to 48.0 moles%, were placed into a newly created genus, Alteromonas; groups which had a GC content of 57.8 to 64.7 moles% were placed into the genus Pseudomonas; and the remaining groups were left unassigned. Twelve groups were given the following designations: Alteromonas communis, A. vaga, A. macleodii, A. marinopraesens, Pseudomonas doudoroffi, P. marina, P. nautica, Alcaligenes pacificus, A. cupidus, A. venustus, and A. aestus. The problems of assigning species of aerobic marine bacteria to genera are

  14. Aerobic Excercise and Research Opportunities to Benefit Impaired Children. (Project AEROBIC). Final Report.

    ERIC Educational Resources Information Center

    Idaho Univ., Moscow.

    The final report summarizes accomplishments of Project AEROBIC (Aerobic Exercise and Research Opportunities to Benefit Impaired Children), which provided a physical education exercise program for severely, profoundly, and multiply handicapped children aged 10-21. Activities are outlined for the 3 year period and include modification of exercise…

  15. Ventricular Septal Defect (VSD)

    MedlinePlus

    ... Your Risk • Symptoms & Diagnosis • Care & Treatment • Tools & Resources Web Booklets on Congenital Heart Defects These online publications ... to you or your child’s defect and concerns. Web Booklet: Adults With Congenital Heart Defects Web Booklet: ...

  16. Neural Tube Defects

    MedlinePlus

    Neural tube defects are birth defects of the brain, spine, or spinal cord. They happen in the first month ... that she is pregnant. The two most common neural tube defects are spina bifida and anencephaly. In spina bifida, ...

  17. Formation of filamentous aerobic granules: role of pH and mechanism.

    PubMed

    Wan, Chunli; Yang, Xue; Lee, Duu-Jong; Zhang, Qinlan; Li, Jieni; Liu, Xiang

    2014-10-01

    Filamentous overgrowth in aerobic granular sludge processes can cause reactor failure. In this work, aerobic granules were cultivated in five identical sequencing batch reactors with acetate or glucose as the carbon source with various values of influent pH (4.5-8). Microscopic observations revealed that acidic pH, rather than the species of carbon source, epistatically controls the aerobic granules with filamentous structure. An acidic pH shifted the structure of the microbial community in the granules, such that the fungus Geotrichum fragrans was the predominant filamentous microorganism therein. The acidic pH reduced the intracellular cyclic diguanylate (c-di-GMP) content for increasing the motility of the bacteria to washout and increase the growth rate of G. fragrans on glucose or acetate, together causing overgrowth of the fungus. Maintaining the suspension under alkaline condition is proposed as an effective way to suppress filamentous overgrowth and maintain granule stability. PMID:24928656

  18. Aerobic sulfur-oxidizing bacteria: Environmental selection and diversification

    NASA Technical Reports Server (NTRS)

    Caldwell, D.

    1985-01-01

    Sulfur-oxidizing bacteria oxidize reduced inorganic compounds to sulfuric acid. Lithotrophic sulfur oxidizer use the energy obtained from oxidation for microbial growth. Heterotrophic sulfur oxidizers obtain energy from the oxidation of organic compounds. In sulfur-oxidizing mixotrophs energy are derived either from the oxidation of inorganic or organic compounds. Sulfur-oxidizing bacteria are usually located within the sulfide/oxygen interfaces of springs, sediments, soil microenvironments, and the hypolimnion. Colonization of the interface is necessary since sulfide auto-oxidizes and because both oxygen and sulfide are needed for growth. The environmental stresses associated with the colonization of these interfaces resulted in the evolution of morphologically diverse and unique aerobic sulfur oxidizers.

  19. Resistance to Aerobic Exercise Training Causes Metabolic Dysfunction and Reveals Novel Exercise-Regulated Signaling Networks

    PubMed Central

    Lessard, Sarah J.; Rivas, Donato A.; Alves-Wagner, Ana B.; Hirshman, Michael F.; Gallagher, Iain J.; Constantin-Teodosiu, Dumitru; Atkins, Ryan; Greenhaff, Paul L.; Qi, Nathan R.; Gustafsson, Thomas; Fielding, Roger A.; Timmons, James A.; Britton, Steven L.; Koch, Lauren G.; Goodyear, Laurie J.

    2013-01-01

    Low aerobic exercise capacity is a risk factor for diabetes and a strong predictor of mortality, yet some individuals are “exercise-resistant” and unable to improve exercise capacity through exercise training. To test the hypothesis that resistance to aerobic exercise training underlies metabolic disease risk, we used selective breeding for 15 generations to develop rat models of low and high aerobic response to training. Before exercise training, rats selected as low and high responders had similar exercise capacities. However, after 8 weeks of treadmill training, low responders failed to improve their exercise capacity, whereas high responders improved by 54%. Remarkably, low responders to aerobic training exhibited pronounced metabolic dysfunction characterized by insulin resistance and increased adiposity, demonstrating that the exercise-resistant phenotype segregates with disease risk. Low responders had impaired exercise-induced angiogenesis in muscle; however, mitochondrial capacity was intact and increased normally with exercise training, demonstrating that mitochondria are not limiting for aerobic adaptation or responsible for metabolic dysfunction in low responders. Low responders had increased stress/inflammatory signaling and altered transforming growth factor-β signaling, characterized by hyperphosphorylation of a novel exercise-regulated phosphorylation site on SMAD2. Using this powerful biological model system, we have discovered key pathways for low exercise training response that may represent novel targets for the treatment of metabolic disease. PMID:23610057

  20. Effect and behaviour of different substrates in relation to the formation of aerobic granular sludge.

    PubMed

    Pronk, M; Abbas, B; Al-Zuhairy, S H K; Kraan, R; Kleerebezem, R; van Loosdrecht, M C M

    2015-06-01

    When aerobic granular sludge is applied for industrial wastewater treatment, different soluble substrates can be present. For stable granular sludge formation on volatile fatty acids (e.g. acetate), production of storage polymers under anaerobic feeding conditions has been shown to be important. This prevents direct aerobic growth on readily available chemical oxygen demand (COD), which is thought to result in unstable granule formation. Here, we investigate the impact of acetate, methanol, butanol, propanol, propionaldehyde, and valeraldehyde on granular sludge formation at 35 °C. Methanogenic archaea, growing on methanol, were present in the aerobic granular sludge system. Methanol was completely converted to methane and carbon dioxide by the methanogenic archaeum Methanomethylovorans uponensis during the 1-h anaerobic feeding period, despite the relative high dissolved oxygen concentration (3.5 mg O2 L(-1)) during the subsequent 2-h aeration period. Propionaldehyde and valeraldehyde were fully disproportionated anaerobically into their corresponding carboxylic acids and alcohols. The organic acids produced were converted to storage polymers, while the alcohols (produced and from influent) were absorbed onto the granular sludge matrix and converted aerobically. Our observations show that easy biodegradable substrates not converted anaerobically into storage polymers could lead to unstable granular sludge formation. However, when the easy biodegradable COD is absorbed in the granules and/or when the substrate is converted by relatively slow growing bacteria in the aerobic period, stable granulation can occur. PMID:25616527

  1. Real-Time Assessment of Guided Bone Regeneration in Standardized Calvarial Defects Using a Combination of Bone Graft and Platelet-Derived Growth Factor With and Without Collagen Membrane: An In Vivo Microcomputed Tomographic and Histologic Experiment in Rats.

    PubMed

    Alrasheed, Abdulaziz; Al-Ahmari, Fatemah; Ramalingam, Sundar; Nooh, Nasser; Wang, Cun-Yu; Al-Hezaimi, Khalid

    2016-01-01

    The aim of the present in vivo microcomputed tomography (μCT) and histologic experiment was to assess the efficacy of guided bone regeneration (GBR) around standardized calvarial defects using recombinant human platelet-derived growth factor (rhPDGF) with and without resorbable collagen membrane (RCM). A total of 50 female Wistar albino rats with a mean age of 7.5 months and mean weight of 275 g were used. The calvarium was exposed following midsagittal scalp incision and flap reflection. A full-thickness standardized calvarial defect (4.6 mm diameter) was created. Study animals were randomly divided into five groups based on biomaterials used for GBR within the defect: (1) no treatment (negative control), (2) bone graft alone (BG), (3) bone graft covered by RCM (BG + RCM), (4) bone graft soaked in rhPDGF (BG + rhPDGF), and (5) bone graft soaked in rhPDGF and covered with RCM (BG + rhPDGF + RCM). In vivo μCT for determination of newly formed bone volume (NFBV) and mineral density (NFBMD) and remnant bone particles volume (RBPV) and mineral density (RBPMD) was done at baseline and at 2, 4, 6, and 8 weeks postoperatively. Eight weeks following surgery, the animals were sacrificed and harvested calvarial specimens were subjected to histologic and biomechanical analysis. There was an increase in NFBV and NFBMD associated with a corresponding decrease in RBPV and RBPMD in all the study groups. Two-way analysis of variance revealed significant differences in the measured values within and between the groups across the timelines examined during the study period (P < .05). While the NFBV was significantly higher in the bone graft, BG + RCM, and BG + rhPDGF + RCM groups, the NFBMD was similar in all the groups except negative control. The greatest decreases in RBPV and RBPMD were observed in the BG + rhPDGF + RCM group in comparison to the other groups. Similarly, BG + rhPDGF + RCM groups had hardness and elastic modulus similar to that of natural bone. The in vivo

  2. The Effect of the Wall Contact and Post-Growth Cool-Down on Defects in CdTe Crystals Grown by 'Contactless' Physical Vapour Transport

    NASA Technical Reports Server (NTRS)

    Palosz, W.; Grasza, K.; Durose, K.; Halliday, D. P.; Boyall, N. M.; Dudley, M.; Raghothamachar, B.; Cai, L.; Curreri, Peter A. (Technical Monitor)

    2002-01-01

    A series of cadmium telluride crystals grown by physical vapor transport without contact with the ampoule walls and cooled at different rates were characterized using synchrotron X-ray topography, photoluminescence, and chemical etching. Strain from sticking to silica glass and its effect on the dislocation density is shown. It was found that very fast cool-down increases dislocation density by at least one order of magnitude. None of the samples had random dislocation distributions but coarse clumping of dislocations on the scale of more than 100 microns was more prevalent in slowly cooled crystals. Photoluminescence revealed that slow cooling favored the donor-acceptor luminescence involving complex A centers. This was diminished in fast cooled material; and effect presumed to be due to dislocation gettering. Fast cooling also enhanced the formation of shallow acceptors. Implications for Bridgman growth of CdTe and the vapor growth of CdZnTe are discussed briefly.

  3. Growth, structure, defects and polarized absorption spectral properties of Er:Yb:YCa4O(BO3)3 crystals

    NASA Astrophysics Data System (ADS)

    Zhong, Degao; Teng, Bing; Kong, Weijin; Zhang, Shiming; Li, Yuyi; Li, Jianhong; Yang, Liting; Cao, Lifeng; Van Smaalen, Sander

    2016-01-01

    YCa4O(BO3)3 (YCOB) crystals co-doped with 3 at% Er3+ and 20 at% Yb3+ were successfully grown by the Czochralski method. X-ray powder diffraction (XRPD) results show that the as-grown Er:Yb:YCOB crystal belongs to the monoclinic system with space group Cm. And the lattice parameters are a=8.076(8) Å, b=16.023(7) Å, c=3.528(4) Å and β=101.15(4)°. Crystal defects were revealed by chemical etching experiments. The density of etch pits, attributed to dislocations and observed on (010) planes, was found to be not uniform along the crystal diameter. The detailed polarized absorption spectra were measured. The polarized absorption cross sections at 977 nm are 1.01×10-20, 1.22×10-20 and 1.05×10-20 cm2 for E//X, E//Y and E//Z, respectively. And the polarized absorption cross sections at 1538 nm is about 1.86×10-20 cm2 for both E//X and E//Z, but for E//Y the result is 1.03×10-20 cm2, which is much smaller. The relationship between the crystal structure and absorption spectra was discussed.

  4. Incomplete penetrance and variable expressivity of a growth defect as a consequence of knocking out two K(+) transporters in the euascomycete fungus Podospora anserina.

    PubMed Central

    Lalucque, Hervé; Silar, Philippe

    2004-01-01

    We describe an example of incomplete penetrance and variable expressivity in the filamentous fungus Podospora anserina, two genetic properties classically associated with mutations in more complex organisms, such as green plants and animals. We show that the knockouts of two TRK-related K(+) transporters of this ascomycete present variability in their phenotype that cannot be attributed to fluctuations of the genetic background or the environment. Thalli of the knockout strains derived from independent monokaryotic ascospores or from a single monokaryotic ascospore and cultivated under standard growth conditions may or may not present impaired growth. When impaired, thalli exhibit a range of phenotypes. Environmental conditions control expressivity to a large extent and penetrance to a low extent. Restoration of functional potassium transport by heterologous expression of K(+) transporters from Neurospora crassa abolishes or strongly diminishes the growth impairment. These data show that incomplete penetrance and variable expressivity can be an intrinsic property of a single Mendelian loss-of-function mutation. They also show that such variability in the expression of a mutant phenotype can be promoted by a phenomenon not obviously related to the well-known chromatin structure modifications, i.e., potassium transport. They provide a framework to understand human channelopathies with similar properties. PMID:15020412

  5. A practical approach for modeling EUVL mask defects

    SciTech Connect

    Gullikson, E.M.; Cerjan, C.; Stearns, D.J.; Mirkarimi, P.B.; Sweeney, D.W.

    2001-06-01

    An approximate method is proposed to calculate the EUV scattering from a defect within a multilayer coating. In this single surface approximation (SSA) the defective multilayer structure is replaced by a single reflecting surface with the shape of the top surface of the multilayer. The range of validity of this approximation has been investigated for Gaussian line defects using 2D finite-difference-time-domain simulations. The SSA is found to be valid for sufficiently low aspect ratio defects such as those expected for the critical defects nucleated by particles on the mask substrate. The critical EUVL defect size is calculated by combining the SSA with a multilayer growth model and aerial image simulations. Another approximate method for calculating the aerial image of an unresolved defect is also discussed. Although the critical substrate defects may be larger than the resolution of higher NA cameras, the point defect approximation provides a useful framework for understanding the printability of a wide range of defects.

  6. Aerobic Granules: Microbial Landscape and Architecture, Stages, and Practical Implications

    PubMed Central

    Holliger, Christof

    2014-01-01

    For the successful application of aerobic granules in wastewater treatment, granules containing an appropriate microbial assembly able to remove contaminants should be retained and propagated within the reactor. To manipulate and/or optimize this process, a good understanding of the formation and dynamic architecture of the granules is desirable. Models of granules often assume a spherical shape with an outer layer and an inner core, but limited information is available regarding the extent of deviations from such assumptions. We report on new imaging approaches to gain detailed insights into the structural characteristics of aerobic granules. Our approach stained all components of the granule to obtain a high quality contrast in the images; hence limitations due to thresholding in the image analysis were overcome. A three-dimensional reconstruction of the granular structure was obtained that revealed the mesoscopic impression of the cavernlike interior of the structure, showing channels and dead-end paths in detail. In “old” granules, large cavities allowed for the irrigation and growth of dense microbial colonies along the path of the channels. Hence, in some areas, paradoxically higher biomass content was observed in the inner part of the granule compared to the outer part. Microbial clusters “rooting” from the interior of the mature granule structure indicate that granules mainly grow via biomass outgrowth and not by aggregation of small particles. We identify and discuss phenomena contributing to the life cycle of aerobic granules. With our approach, volumetric tetrahedral grids are generated that may be used to validate complex models of granule formation. PMID:24657859

  7. Aerobic granules: microbial landscape and architecture, stages, and practical implications.

    PubMed

    Gonzalez-Gil, Graciela; Holliger, Christof

    2014-06-01

    For the successful application of aerobic granules in wastewater treatment, granules containing an appropriate microbial assembly able to remove contaminants should be retained and propagated within the reactor. To manipulate and/or optimize this process, a good understanding of the formation and dynamic architecture of the granules is desirable. Models of granules often assume a spherical shape with an outer layer and an inner core, but limited information is available regarding the extent of deviations from such assumptions. We report on new imaging approaches to gain detailed insights into the structural characteristics of aerobic granules. Our approach stained all components of the granule to obtain a high quality contrast in the images; hence limitations due to thresholding in the image analysis were overcome. A three-dimensional reconstruction of the granular structure was obtained that revealed the mesoscopic impression of the cavernlike interior of the structure, showing channels and dead-end paths in detail. In "old" granules, large cavities allowed for the irrigation and growth of dense microbial colonies along the path of the channels. Hence, in some areas, paradoxically higher biomass content was observed in the inner part of the granule compared to the outer part. Microbial clusters "rooting" from the interior of the mature granule structure indicate that granules mainly grow via biomass outgrowth and not by aggregation of small particles. We identify and discuss phenomena contributing to the life cycle of aerobic granules. With our approach, volumetric tetrahedral grids are generated that may be used to validate complex models of granule formation. PMID:24657859

  8. Controlling the catalytic aerobic oxidation of phenols.

    PubMed

    Esguerra, Kenneth Virgel N; Fall, Yacoub; Petitjean, Laurène; Lumb, Jean-Philip

    2014-05-28

    The oxidation of phenols is the subject of extensive investigation, but there are few catalytic aerobic examples that are chemo- and regioselective. Here we describe conditions for the ortho-oxygenation or oxidative coupling of phenols under copper (Cu)-catalyzed aerobic conditions that give rise to ortho-quinones, biphenols or benzoxepines. We demonstrate that each product class can be accessed selectively by the appropriate choice of Cu(I) salt, amine ligand, desiccant and reaction temperature. In addition, we evaluate the effects of substituents on the phenol and demonstrate their influence on selectivity between ortho-oxygenation and oxidative coupling pathways. These results create an important precedent of catalyst control in the catalytic aerobic oxidation of phenols and set the stage for future development of catalytic systems and mechanistic investigations. PMID:24784319

  9. [Anaerobic-aerobic infection in acute appendicitis].

    PubMed

    Mamchich, V I; Ulitovskiĭ, I V; Savich, E I; Znamenskiĭ, V A; Beliaeva, O A

    1998-01-01

    362 patients with acute appendicitis (AA) were examined. For microbiological diagnosis of aerobic and anaerobic nonclostridial microflora we used complex accelerated methods (including evaluation of gram-negative microorganisms in comparison with tinctorial-fermentative method of differential staining according to oxygen sensitivity of catalasopositive together with aerobic and cathalasonegative anaerobic microorganisms) as well as complete bacteriologic examination with determination of sensitivity of the above microorganism to antimicrobial remedies. High rate of aerobic-anaerobic microbial associations and substantial identity of microflora from appendicis and exudate from abdominal cavity was revealed, which evidenced the leading role of endogenous microorganisms in etiology and pathogenesis of AA and peritonitis i. e. autoinfection. In patients with destructive forms of AA, complicated by peritonitis it is recommended to use the accelerated method of examination of pathologic material as well as the complete scheme of examination with the identification of the isolated microorganisms and the correction of antibiotic treatment. PMID:9511291

  10. Drying and recovery of aerobic granules.

    PubMed

    Hu, Jianjun; Zhang, Quanguo; Chen, Yu-You; Lee, Duu-Jong

    2016-10-01

    To dehydrate aerobic granules to bone-dry form was proposed as a promising option for long-term storage of aerobic granules. This study cultivated aerobic granules with high proteins/polysaccharide ratio and then dried these granules using seven protocols: drying at 37°C, 60°C, 4°C, under sunlight, in dark, in a flowing air stream or in concentrated acetone solutions. All dried granules experienced volume shrinkage of over 80% without major structural breakdown. After three recovery batches, although with loss of part of the volatile suspended solids, all dried granules were restored most of their original size and organic matter degradation capabilities. The strains that can survive over the drying and storage periods were also identified. Once the granules were dried, they can be stored over long period of time, with minimal impact yielded by the applied drying protocols. PMID:27392096

  11. The Effect of the Wall Contact and Post-Growth, Cool-Down on Defects in CdTe Crystals Grown By 'Contactless' PVT

    NASA Technical Reports Server (NTRS)

    Palosz, W.; Grasza, K.; Dudley, M.; Raghothamachar, B.; Cai, L.; Dunrose, K.; Halliday, D.; Boyall, N. M.; Rose, M. Franklin (Technical Monitor)

    2001-01-01

    To take a maximum advantage of materials processing in microgravity for understanding the effects of gravity, gravity-independent effects should be minimized. In crystal growth, the quality of the grown crystals may depend, among other factors, on their interaction with the walls of the processing container during and after growth, and on the rate of the crystal cool-down at the end of the process. To investigate the above phenomena, a series of CdTe crystal growth processes was carried out. The crystals were grown by physical vapor transport without contact with the side walls of the silica glass ampoules. To eliminate the effect of the seed quality, and to reduce the number of nuclei and related crystal grains, the Low Supersaturation Nucleation technique was applied. The source temperature was 930 C, the undercooling was a few degrees. The crystals, having the diameter of 25 mm, grew at the rate of a few mm per day. The post-growth cool-down to the room temperature was conducted at different rates, and lasted from a few minutes to four days. The crystals were characterized using chemical etching, low temperature luminescence, and Synchrotron White Beam X-ray Topography techniques. The dislocation (etch pit) density was measured and its distribution was analyzed by comparison with Poisson curves and with the Normalized Radial Distribution Correlation Function. In the regions where the crystal is in contact with silica, the materials show a considerable strain field which extends for a few mm or more from the silica-crystal interface. In the reference crystal grown with contact with the ampoule walls, and when the crystals are cooled at the highest rates, the etch pit/dislocation density is in the high 10(exp 5) per square centimeter region. Typical EPD values for lower cool-down rates are in the lower 10(exp 4) per square centimeter region. In some areas the actual dislocation density was about 10(exp 3) per square centimeter or even less. No apparent effect of

  12. INACTIVATION OF ENTERIC PATHOGENS DURING AEROBIC DIGESTION OF WASTEWATER SLUDGE

    EPA Science Inventory

    The effects of aerobic and anaerobic digestion on enteric viruses, enteric bacteria, total aerobic bacteria, and intestinal parasites were studied under laboratory and field conditions. Under laboratory conditions, the temperature of the sludge digestion was the major factor infl...

  13. ANAEROBIC AND AEROBIC TREATMENT OF CHLORINATED ALIPHATIC COMPOUNDS

    EPA Science Inventory

    Biological degradation of 12 chlorinated aliphatic compounds (CACs) was assessed in bench-top reactors and in serum bottle tests. Three continuously mixed daily batch-fed reactor systems were evaluated: anaerobic, aerobic, and sequential-anaerobic-aerobic (sequential). Glucose,...

  14. On Aerobic Exercise and Behavioral and Neural Plasticity

    PubMed Central

    Swain, Rodney A.; Berggren, Kiersten L.; Kerr, Abigail L.; Patel, Ami; Peplinski, Caitlin; Sikorski, Angela M.

    2012-01-01

    Aerobic exercise promotes rapid and profound alterations in the brain. Depending upon the pattern and duration of exercise, these changes in the brain may extend beyond traditional motor areas to regions and structures normally linked to learning, cognition, and emotion. Exercise-induced alterations may include changes in blood flow, hormone and growth factor release, receptor expression, angiogenesis, apoptosis, neurogenesis, and synaptogenesis. Together, we believe that these changes underlie elevations of mood and prompt the heightened behavioral plasticity commonly observed following adoption of a chronic exercise regimen. In the following paper, we will explore both the psychological and psychobiological literatures relating to exercise effects on brain in both human and non-human animals and will attempt to link plastic changes in these neural structures to modifications in learned behavior and emotional expression. In addition, we will explore the therapeutic potential of exercise given recent reports that aerobic exercise may serve as a neuroprotectant and can also slow cognitive decline during normal and pathological aging. PMID:24961267

  15. Kibdelomycin Is a Bactericidal Broad-Spectrum Aerobic Antibacterial Agent

    PubMed Central

    Dayananth, Priya; Balibar, Carl J.; Garlisi, Charles G.; Lu, Jun; Kishii, Ryuta; Takei, Masaya; Fukuda, Yasumichi; Ha, Sookhee; Young, Katherine

    2015-01-01

    Bacterial resistance to antibiotics continues to grow and pose serious challenges, while the discovery rate for new antibiotics declines. Kibdelomycin is a recently discovered natural-product antibiotic that inhibits bacterial growth by inhibiting the bacterial DNA replication enzymes DNA gyrase and topoisomerase IV. It was reported to be a broad-spectrum aerobic Gram-positive agent with selective inhibition of the anaerobic bacterium Clostridium difficile. We have extended the profiling of kibdelomycin by using over 196 strains of Gram-positive and Gram-negative aerobic pathogens recovered from worldwide patient populations. We report the MIC50s, MIC90s, and bactericidal activities of kibdelomycin. We confirm the Gram-positive spectrum and report for the first time that kibdelomycin shows strong activity (MIC90, 0.125 μg/ml) against clinical strains of the Gram-negative nonfermenter Acinetobacter baumannii but only weak activity against Pseudomonas aeruginosa. We confirm that well-characterized resistant strains of Staphylococcus aureus and Streptococcus pneumoniae show no cross-resistance to kibdelomycin and quinolones and coumarin antibiotics. We also show that kibdelomycin is not subject to efflux in Pseudomonas, though it is in Escherichia coli, and it is generally affected by the outer membrane permeability entry barrier in the nonfermenters P. aeruginosa and A. baumannii, which may be addressable by structure-based chemical modification. PMID:25845866

  16. Development of microorganisms in the chernozem under aerobic and anaerobic conditions

    NASA Astrophysics Data System (ADS)

    Polyanskaya, L. M.; Gorbacheva, M. A.; Milanovskii, E. Yu.; Zvyagintsev, D. G.

    2010-03-01

    A microbial succession was studied under aerobic and anaerobic conditions by means of experiments with microcosms in different horizons of a chernozem. It was revealed that, under aerobic conditions, all the microorganisms grow irrespective of the soil horizon; fungi and bacteria grow at the first succession stages, and actinomycetes grow at the last stages. It was shown that, in the case of a simulated anaerobiosis commonly used to study anaerobic populations of bacteria, the mycelium of micromycetes grows in the upper part of the chernozem’s A horizon. Under anaerobic conditions, the peak of the mycelium development is shifted from the 3rd to 7th days (typical for aerobic conditions) to the 7th to 15th days of incubation. The level of mycelium length’s stabilization under aerobic and anaerobic conditions also differs: it is higher or lower than the initial one, respectively. Under anaerobic conditions, the growth of fungal mycelium, bacteria, and actinomycetes in the lower part of the A horizon and in the B horizon is extremely weak. There was not any observed growth of actinomycetes in all the chernozem’s horizons under anaerobic conditions.

  17. Growth of Defect-Free 3C-Sic on 4H- and 6H-SIC Mesas Using Step-Free Surface Heteroepitaxy

    NASA Technical Reports Server (NTRS)

    Neudeck, Philip G.; Powell, J. Anthony; Trunek, Andrew J.; Huang, Xianrong R.; Dudley, Michael

    2002-01-01

    A new growth process, herein named step-free surface heteroepitaxy, has achieved 3C-SiC films completely free of double positioning boundaries and stacking faults on 4H-SiC and 6H-SiC substrate mesas. The process is based upon the initial 2-dimensional nucleation and lateral expansion of a single island of 3C-SiC on a 4H- or 6H-SiC mesa surface that is completely free of bilayer surface steps. Our experimental results indicate that substrate-epilayer in-plane lattice mismatch (Delta/a = 0.0854% for 3C/4H) is at least partially relieved parallel to the interface in the initial bilayers of the heterofilm, producing an at least partially relaxed 3C-SiC film without dislocations that undesirably thread through the thickness of the epilayer. This result should enable realization of improved 3C-SiC devices.

  18. Reflections on Psychotherapy and Aerobic Exercise.

    ERIC Educational Resources Information Center

    Silverman, Wade

    This document provides a series of reflections by a practicing psychologist on the uses of aerobic workouts in psychotherapy. Two case histories are cited to illustrate the contention that the mode of exercise, rather than simply its presence or absence, is the significant indicator of a patient's emotional well-being or psychopathology. The first…

  19. Aerobic Exercise Prescription for Rheumatoid Arthritics.

    ERIC Educational Resources Information Center

    Evans, Blanche W.; Williams, Hilda L.

    The use of exercise as a general treatment for rheumatoid arthritics (RA) has included range of motion, muscular strength, water exercise and rest therapy while virtually ignoring possible benefits of aerobic exercise. The purposes of this project were to examine the guidelines for exercise prescription in relation to this special population and…

  20. Strengthening aerobic granule by salt precipitation.

    PubMed

    Chen, Yu-You; Pan, Xiangliang; Li, Jun; Lee, Duu-Jong

    2016-10-01

    Structural stability of aerobic granules is generally poor during long-term operation. This study precipitated seven salts inside aerobic granules using supersaturated solutions of (NH4)3PO4, CaCO3, CaSO4, MgCO3, Mg3(PO4)2, Ca3(PO4)2 or SiO2 to enhance their structural stability. All precipitated granules have higher interior strength at ultrasonic field and reveal minimal loss in organic matter degradation capability at 160-d sequential batch reactor tests. The strength enhancement followed: Mg3(PO4)2=CaSO4>SiO2>(NH4)3PO4>MgCO3>CaCO3=Ca3(PO4)2>original. Also, the intra-granular solution environment can be buffered by the precipitate MgCO3 to make the aerobic granules capable of degradation of organic matters at pH 3. Salt precipitation is confirmed a simple and cost-effective modification method to extend the applicability of aerobic granules for wastewater treatments. PMID:27377228

  1. AEROBIC DENITRIFICATION: IMPLICATIONS FOR NITROGEN FATE MODELING

    EPA Science Inventory

    In the Mississippi, as well as most nitrogen-degraded rivers and streams, NO3- is the dominant N species and therefore understanding its biogeochemical behavior is critical for accurate nitrogen fate modeling. To our knowledge this is the first work to report aerobic denitrificat...

  2. Ventilation and Speech Characteristics during Submaximal Aerobic Exercise

    ERIC Educational Resources Information Center

    Baker, Susan E.; Hipp, Jenny; Alessio, Helaine

    2008-01-01

    Purpose: This study examined alterations in ventilation and speech characteristics as well as perceived dyspnea during submaximal aerobic exercise tasks. Method: Twelve healthy participants completed aerobic exercise-only and simultaneous speaking and aerobic exercise tasks at 50% and 75% of their maximum oxygen consumption (VO[subscript 2] max).…

  3. Adolescents' Interest and Performances in Aerobic Fitness Testing

    ERIC Educational Resources Information Center

    Zhu, Xihe; Chen, Senlin; Parrott, James

    2014-01-01

    This study examined adolescents' interest in aerobic fitness testing and its relation to the test performances. Adolescents (N = 356) from three middle schools participated in the study. The participants took two aerobic fitness tests: the Progressive Aerobic Cardiovascular Endurance Run (PACER) and One-Mile Run (1MR) with a two-day interval,…

  4. A proposed aerobic granules size development scheme for aerobic granulation process.

    PubMed

    Dahalan, Farrah Aini; Abdullah, Norhayati; Yuzir, Ali; Olsson, Gustaf; Salmiati; Hamdzah, Myzairah; Din, Mohd Fadhil Mohd; Ahmad, Siti Aqlima; Khalil, Khalilah Abdul; Anuar, Aznah Nor; Noor, Zainura Zainon; Ujang, Zaini

    2015-04-01

    Aerobic granulation is increasingly used in wastewater treatment due to its unique physical properties and microbial functionalities. Granule size defines the physical properties of granules based on biomass accumulation. This study aims to determine the profile of size development under two physicochemical conditions. Two identical bioreactors namely Rnp and Rp were operated under non-phototrophic and phototrophic conditions, respectively. An illustrative scheme was developed to comprehend the mechanism of size development that delineates the granular size throughout the granulation. Observations on granules' size variation have shown that activated sludge revolutionised into the form of aerobic granules through the increase of biomass concentration in bioreactors which also determined the changes of granule size. Both reactors demonstrated that size transformed in a similar trend when tested with and without illumination. Thus, different types of aerobic granules may increase in size in the same way as recommended in the aerobic granule size development scheme. PMID:25661308

  5. Functional characterization of the ribosome biogenesis factors PES, BOP1, and WDR12 (PeBoW), and mechanisms of defective cell growth and proliferation caused by PeBoW deficiency in Arabidopsis

    PubMed Central

    Ahn, Chang Sook; Cho, Hui Kyung; Lee, Du-Hwa; Sim, Hee-Jung; Kim, Sang-Gyu; Pai, Hyun-Sook

    2016-01-01

    The nucleolar protein pescadillo (PES) controls biogenesis of the 60S ribosomal subunit through functional interactions with Block of Proliferation 1 (BOP1) and WD Repeat Domain 12 (WDR12) in plants. In this study, we determined protein characteristics and in planta functions of BOP1 and WDR12, and characterized defects in plant cell growth and proliferation caused by a deficiency of PeBoW (PES-BOP1-WDR12) proteins. Dexamethasone-inducible RNAi of BOP1 and WDR12 caused developmental arrest and premature senescence in Arabidopsis, similar to the phenotype of PES RNAi. Both the N-terminal domain and WD40 repeats of BOP1 and WDR12 were critical for specific associations with 60S/80S ribosomes. In response to nucleolar stress or DNA damage, PeBoW proteins moved from the nucleolus to the nucleoplasm. Kinematic analyses of leaf growth revealed that depletion of PeBoW proteins led to dramatically suppressed cell proliferation, cell expansion, and epidermal pavement cell differentiation. A deficiency in PeBoW proteins resulted in reduced cyclin-dependent kinase Type A activity, causing reduced phosphorylation of histone H1 and retinoblastoma-related (RBR) protein. PeBoW silencing caused rapid transcriptional modulation of cell-cycle genes, including reduction of E2Fa and Cyclin D family genes, and induction of several KRP genes, accompanied by down-regulation of auxin-related genes and up-regulation of jasmonic acid-related genes. Taken together, these results suggest that the PeBoW proteins involved in ribosome biogenesis play a critical role in plant cell growth and survival, and their depletion leads to inhibition of cell-cycle progression, possibly modulated by phytohormone signaling. PMID:27440937

  6. Functional characterization of the ribosome biogenesis factors PES, BOP1, and WDR12 (PeBoW), and mechanisms of defective cell growth and proliferation caused by PeBoW deficiency in Arabidopsis.

    PubMed

    Ahn, Chang Sook; Cho, Hui Kyung; Lee, Du-Hwa; Sim, Hee-Jung; Kim, Sang-Gyu; Pai, Hyun-Sook

    2016-09-01

    The nucleolar protein pescadillo (PES) controls biogenesis of the 60S ribosomal subunit through functional interactions with Block of Proliferation 1 (BOP1) and WD Repeat Domain 12 (WDR12) in plants. In this study, we determined protein characteristics and in planta functions of BOP1 and WDR12, and characterized defects in plant cell growth and proliferation caused by a deficiency of PeBoW (PES-BOP1-WDR12) proteins. Dexamethasone-inducible RNAi of BOP1 and WDR12 caused developmental arrest and premature senescence in Arabidopsis, similar to the phenotype of PES RNAi. Both the N-terminal domain and WD40 repeats of BOP1 and WDR12 were critical for specific associations with 60S/80S ribosomes. In response to nucleolar stress or DNA damage, PeBoW proteins moved from the nucleolus to the nucleoplasm. Kinematic analyses of leaf growth revealed that depletion of PeBoW proteins led to dramatically suppressed cell proliferation, cell expansion, and epidermal pavement cell differentiation. A deficiency in PeBoW proteins resulted in reduced cyclin-dependent kinase Type A activity, causing reduced phosphorylation of histone H1 and retinoblastoma-related (RBR) protein. PeBoW silencing caused rapid transcriptional modulation of cell-cycle genes, including reduction of E2Fa and Cyclin D family genes, and induction of several KRP genes, accompanied by down-regulation of auxin-related genes and up-regulation of jasmonic acid-related genes. Taken together, these results suggest that the PeBoW proteins involved in ribosome biogenesis play a critical role in plant cell growth and survival, and their depletion leads to inhibition of cell-cycle progression, possibly modulated by phytohormone signaling. PMID:27440937

  7. A de novo 0.63 Mb 6q25.1 deletion associated with growth failure, congenital heart defect, underdeveloped cerebellar vermis, abnormal cutaneous elasticity and joint laxity.

    PubMed

    Salpietro, Vincenzo; Ruggieri, Martino; Mankad, Kshitij; Di Rosa, Gabriella; Granata, Francesca; Loddo, Italia; Moschella, Emanuela; Calabro, Maria Pia; Capalbo, Anna; Bernardini, Laura; Novelli, Antonio; Polizzi, Agata; Seidler, Daniela G; Arrigo, Teresa; Briuglia, Silvana

    2015-09-01

    Deletions of the long arm of chromosome 6 are rare and are characterized by great clinical variability according to the deletion breakpoint. We report a on 6-year-old girl with a de novo 0.63 Mb deletion on chromosome 6q25.1 who demonstrated multiple congenital anomalies including a ventricular septal defect and an underdeveloped cerebellar vermis. She presented with severe pre- and post-natal growth failure, hyperextensible small joints (Beighton scores = 8/9; with normal parental scores), and an abnormally elastic, redundant skin. Abnormally high upper/lower segment ratio (i.e., 1.34 = > 3SD), mild dysmorphic facial features and developmental delay were also present. The girl's phenotype was compared with: (i) two girls, each previously reported by Bisgaard et al. and Caselli et al. with similar albeit larger (2.6-7.21 Mb) deletions; (ii) seven additional individuals (6 M; 1 F) harboring deletions within the 6q25.1 region reported in the literature; and (iii) ten further patients (5 M; 4 F; 1 unrecorded sex) recorded in the DECIPHER 6.0 database. We reported on the present girl as her findings could contribute to advance the phenotype of 6q deletions. In addition, the present deletion is the smallest so far recorded in the 6q25 region encompassing eight known genes [vs. 41 of Bisgaard et al., and 23 of Caselli et al.,], including the TAB2 (likely responsible for the girl's congenital heart defect), LATS1 gene, and the UST gene (a regulator of the homeostasis of proteoglycans, which could have played a role in the abnormal dermal and cartilage elasticity). PMID:25940952

  8. Hexokinase-2-mediated aerobic glycolysis is integral to cerebellar neurogenesis and pathogenesis of medulloblastoma

    PubMed Central

    2013-01-01

    Background While aerobic glycolysis is linked to unconstrained proliferation in cancer, less is known about its physiological role. Why this metabolic program that promotes tumor growth is preserved in the genome has thus been unresolved. We tested the hypothesis that aerobic glycolysis derives from developmental processes that regulate rapid proliferation. Methods We performed an integrated analysis of metabolism and gene expression in cerebellar granule neuron progenitors (CGNPs) with and without Sonic Hedgehog (Shh), their endogenous mitogen. Because our analysis highlighted Hexokinase-2 (Hk2) as a key metabolic regulator induced by Shh, we studied the effect of conditional genetic Hk2 deletion in CGNP development. We then crossed Hk2 conditional knockout mice with transgenic SmoM2 mice that develop spontaneous medulloblastoma and determined changes in SmoM2-driven tumorigenesis. Results We show that Shh and phosphoinositide 3-kinase (PI3K) signaling combine to induce an Hk2-dependent glycolytic phenotype in CGNPs. This phenotype is recapitulated in medulloblastoma, a malignant tumor of CGNP origin. Importantly, cre-mediated ablation of Hk2 abrogated aerobic glycolysis, disrupting CGNP development and Smoothened-induced tumorigenesis. Comparing tumorigenesis in medulloblastoma-prone SmoM2 mice with and without functional Hk2, we demonstrate that loss of aerobic glycolysis reduces the aggressiveness of medulloblastoma, causing tumors to grow as indolent lesions and allowing long-term survival of tumor bearing mice. Conclusions Our investigations demonstrate that aerobic glycolysis in cancer derives from developmental mechanisms that persist in tumorigenesis. Moreover, we demonstrate in a primary tumor model the anti-cancer potential of blocking aerobic glycolysis by targeting Hk2. See commentary article:http://www.biomedcentral.com/1741-7007/11/3 PMID:24280485

  9. Subcellular transcriptome alterations in a cell culture model of spinal muscular atrophy point to widespread defects in axonal growth and presynaptic differentiation

    PubMed Central

    Saal, Lena; Briese, Michael; Kneitz, Susanne; Glinka, Michael

    2014-01-01

    Neuronal function critically depends on coordinated subcellular distribution of mRNAs. Disturbed mRNA processing and axonal transport has been found in spinal muscular atrophy and could be causative for dysfunction and degeneration of motoneurons. Despite the advances made in characterizing the transport mechanisms of several axonal mRNAs, an unbiased approach to identify the axonal repertoire of mRNAs in healthy and degenerating motoneurons has been lacking. Here we used compartmentalized microfluidic chambers to investigate the somatodendritic and axonal mRNA content of cultured motoneurons by microarray analysis. In axons, transcripts related to protein synthesis and energy production were enriched relative to the somatodendritic compartment. Knockdown of Smn, the protein deficient in spinal muscular atrophy, produced a large number of transcript alterations in both compartments. Transcripts related to immune functions, including MHC class I genes, and with roles in RNA splicing were up-regulated in the somatodendritic compartment. On the axonal side, transcripts associated with axon growth and synaptic activity were down-regulated. These alterations provide evidence that subcellular localization of transcripts with axonal functions as well as regulation of specific transcripts with nonautonomous functions is disturbed in Smn-deficient motoneurons, most likely contributing to the pathophysiology of spinal muscular atrophy. PMID:25246652

  10. A Selaginella lepidophylla Trehalose-6-Phosphate Synthase Complements Growth and Stress-Tolerance Defects in a Yeast tps1 Mutant1

    PubMed Central

    Zentella, Rodolfo; Mascorro-Gallardo, José O.; Van Dijck, Patrick; Folch-Mallol, Jorge; Bonini, Beatriz; Van Vaeck, Christophe; Gaxiola, Roberto; Covarrubias, Alejandra A.; Nieto-Sotelo, Jorge; Thevelein, Johan M.; Iturriaga, Gabriel

    1999-01-01

    The accumulation of the disaccharide trehalose in anhydrobiotic organisms allows them to survive severe environmental stress. A plant cDNA, SlTPS1, encoding a 109-kD protein, was isolated from the resurrection plant Selaginella lepidophylla, which accumulates high levels of trehalose. Protein-sequence comparison showed that SlTPS1 shares high similarity to trehalose-6-phosphate synthase genes from prokaryotes and eukaryotes. SlTPS1 mRNA was constitutively expressed in S. lepidophylla. DNA gel-blot analysis indicated that SlTPS1 is present as a single-copy gene. Transformation of a Saccharomyces cerevisiae tps1Δ mutant disrupted in the ScTPS1 gene with S. lepidophylla SlTPS1 restored growth on fermentable sugars and the synthesis of trehalose at high levels. Moreover, the SlTPS1 gene introduced into the tps1Δ mutant was able to complement both deficiencies: sensitivity to sublethal heat treatment at 39°C and induced thermotolerance at 50°C. The osmosensitive phenotype of the yeast tps1Δ mutant grown in NaCl and sorbitol was also restored by the SlTPS1 gene. Thus, SlTPS1 protein is a functional plant homolog capable of sustaining trehalose biosynthesis and could play a major role in stress tolerance in S. lepidophylla. PMID:10198107

  11. Loss of function of cinnamyl alcohol dehydrogenase 1 leads to unconventional lignin and a temperature-sensitive growth defect in Medicago truncatula.

    PubMed

    Zhao, Qiao; Tobimatsu, Yuki; Zhou, Rui; Pattathil, Sivakumar; Gallego-Giraldo, Lina; Fu, Chunxiang; Jackson, Lisa A; Hahn, Michael G; Kim, Hoon; Chen, Fang; Ralph, John; Dixon, Richard A

    2013-08-13

    There is considerable debate over the capacity of the cell wall polymer lignin to incorporate unnatural monomer units. We have identified Tnt1 retrotransposon insertion mutants of barrel medic (Medicago truncatula) that show reduced lignin autofluorescence under UV microscopy and red coloration in interfascicular fibers. The phenotype is caused by insertion of retrotransposons into a gene annotated as encoding cinnamyl alcohol dehydrogenase, here designated M. truncatula CAD1. NMR analysis indicated that the lignin is derived almost exclusively from coniferaldehyde and sinapaldehyde and is therefore strikingly different from classical lignins, which are derived mainly from coniferyl and sinapyl alcohols. Despite such a major alteration in lignin structure, the plants appear normal under standard conditions in the greenhouse or growth chamber. However, the plants are dwarfed when grown at 30 °C. Glycome profiling revealed an increased extractability of some xylan and pectin epitopes from the cell walls of the cad1-1 mutant but decreased extractability of others, suggesting that aldehyde-dominant lignin significantly alters cell wall structure. PMID:23901113

  12. Loss of function of cinnamyl alcohol dehydrogenase 1 leads to unconventional lignin and a temperature-sensitive growth defect in Medicago truncatula

    PubMed Central

    Zhao, Qiao; Tobimatsu, Yuki; Zhou, Rui; Pattathil, Sivakumar; Gallego-Giraldo, Lina; Fu, Chunxiang; Jackson, Lisa A.; Hahn, Michael G.; Kim, Hoon; Chen, Fang; Ralph, John; Dixon, Richard A.

    2013-01-01

    There is considerable debate over the capacity of the cell wall polymer lignin to incorporate unnatural monomer units. We have identified Tnt1 retrotransposon insertion mutants of barrel medic (Medicago truncatula) that show reduced lignin autofluorescence under UV microscopy and red coloration in interfascicular fibers. The phenotype is caused by insertion of retrotransposons into a gene annotated as encoding cinnamyl alcohol dehydrogenase, here designated M. truncatula CAD1. NMR analysis indicated that the lignin is derived almost exclusively from coniferaldehyde and sinapaldehyde and is therefore strikingly different from classical lignins, which are derived mainly from coniferyl and sinapyl alcohols. Despite such a major alteration in lignin structure, the plants appear normal under standard conditions in the greenhouse or growth chamber. However, the plants are dwarfed when grown at 30 °C. Glycome profiling revealed an increased extractability of some xylan and pectin epitopes from the cell walls of the cad1-1 mutant but decreased extractability of others, suggesting that aldehyde-dominant lignin significantly alters cell wall structure. PMID:23901113

  13. A Putative ABC Transporter Permease Is Necessary for Resistance to Acidified Nitrite and EDTA in Pseudomonas aeruginosa under Aerobic and Anaerobic Planktonic and Biofilm Conditions

    PubMed Central

    McDaniel, Cameron; Su, Shengchang; Panmanee, Warunya; Lau, Gee W.; Browne, Tristan; Cox, Kevin; Paul, Andrew T.; Ko, Seung-Hyun B.; Mortensen, Joel E.; Lam, Joseph S.; Muruve, Daniel A.; Hassett, Daniel J.

    2016-01-01

    Pseudomonas aeruginosa (PA) is an important airway pathogen of cystic fibrosis and chronic obstructive disease patients. Multiply drug resistant PA is becoming increasing prevalent and new strategies are needed to combat such insidious organisms. We have previously shown that a mucoid, mucA22 mutant PA is exquisitely sensitive to acidified nitrite (A-NO2−, pH 6.5) at concentrations that are well tolerated in humans. Here, we used a transposon mutagenesis approach to identify PA mutants that are hypersensitive to A-NO2−. Among greater than 10,000 mutants screened, we focused on PA4455, in which the transposon was found to disrupt the production of a putative cytoplasmic membrane-spanning ABC transporter permease. The PA4455 mutant was not only highly sensitive to A-NO2−, but also the membrane perturbing agent, EDTA and the antibiotics doxycycline, tigecycline, colistin, and chloramphenicol, respectively. Treatment of bacteria with A-NO2− plus EDTA, however, had the most dramatic and synergistic effect, with virtually all bacteria killed by 10 mM A-NO2−, and EDTA (1 mM, aerobic, anaerobic). Most importantly, the PA4455 mutant was also sensitive to A-NO2− in biofilms. A-NO2− sensitivity and an anaerobic growth defect was also noted in two mutants (rmlC and wbpM) that are defective in B-band LPS synthesis, potentially indicating a membrane defect in the PA4455 mutant. Finally, this study describes a gene, PA4455, that when mutated, allows for dramatic sensitivity to the potential therapeutic agent, A-NO2− as well as EDTA. Furthermore, the synergy between the two compounds could offer future benefits against antibiotic resistant PA strains. PMID:27064218

  14. Ecology of aerobic anoxygenic phototrophs in aquatic environments.

    PubMed

    Koblížek, Michal

    2015-11-01

    Recognition of the environmental role of photoheterotrophic bacteria has been one of the main themes of aquatic microbiology over the last 15 years. Aside from cyanobacteria and proteorhodopsin-containing bacteria, aerobic anoxygenic phototrophic (AAP) bacteria are the third most numerous group of phototrophic prokaryotes in the ocean. This functional group represents a diverse assembly of species which taxonomically belong to various subgroups of Alpha-, Beta- and Gammaproteobacteria. AAP bacteria are facultative photoheterotrophs which use bacteriochlorophyll-containing reaction centers to harvest light energy. The light-derived energy increases their bacterial growth efficiency, which provides a competitive advantage over heterotrophic species. Thanks to their enzymatic machinery AAP bacteria are active, rapidly growing organisms which contribute significantly to the recycling of organic matter. This chapter summarizes the current knowledge of the ecology of AAP bacteria in aquatic environments, implying their specific role in the microbial loop. PMID:26139241

  15. Aerobic Fitness Linked to Cortical Brain Development in Adolescent Males: Preliminary Findings Suggest a Possible Role of BDNF Genotype

    PubMed Central

    Herting, Megan M.; Keenan, Madison F.; Nagel, Bonnie J.

    2016-01-01

    Aerobic exercise has been shown to impact brain structure and cognition in children and adults. Exercise-induced activation of a growth protein known as brain derived neurotrophic factor (BDNF) is thought to contribute to such relationships. To date, however, no study has examined how aerobic fitness relates to cortical brain structure during development and if BDNF genotype moderates these relationships. Using structural magnetic resonance imaging (MRI) and FreeSurfer, the current study examined how aerobic fitness relates to volume, thickness, and surface area in 34 male adolescents, 15 to 18 years old. Moreover, we examined if the val66met BDNF genotype moderated these relationships. We hypothesized that aerobic fitness would relate to greater thickness and volumes in frontal, parietal, and motor regions, and that these relationships would be less robust in individuals carrying a Met allele, since this genotype leads to lower BDNF expression. We found that aerobic fitness positively related to right rostral middle frontal cortical volume in all adolescents. However, results also showed BDNF genotype moderated the relationship between aerobic fitness and bilateral medial precuneus surface area, with a positive relationship seen in individuals with the Val/Val allele, but no relationship detected in those adolescents carrying a Met allele. Lastly, using self-reported levels of aerobic activity, we found that higher-fit adolescents showed larger right medial pericalcarine, right cuneus and left precuneus surface areas as compared to their low-fit peers. Our findings suggest that aerobic fitness is linked to cortical brain development in male adolescents, and that more research is warranted to determine how an individual’s genes may influence these relationships. PMID:27445764

  16. Altered pituitary growth hormone (GH) regulation in streptozotocin-diabetic rats: a combined defect of hypothalamic somatostatin and GH-releasing factor.

    PubMed

    Olchovsky, D; Bruno, J F; Wood, T L; Gelato, M C; Leidy, J W; Gilbert, J M; Berelowitz, M

    1990-01-01

    Diabetes mellitus in the rat is associated with loss of pulsatile GH secretion. An interplay between hypothalamic GH-releasing factor (GRF) and inhibitory factor [somatostatin (SRIF)] secretion is thought to account for episodic pituitary GH release. An increase in SRIF tone/action or a decrease in GRF release/response in diabetic rats could account for the suppressed GH levels. Pituitaries from streptozotocin-diabetic rats contained less GH than controls (15.9 +/- 2.5 vs. 29.5 +/- 4.6 micrograms/mg; P less than 0.05) despite normal somatotrope representation, as demonstrated using immunofluorescence studies. Basal GH secretion from monolayer culture of dispersed anterior pituitary (AP) cells from diabetic rats was proportionately decreased (150 +/- 10 vs. 103 +/- 10 ng/10(5) cells; P less than 0.005). GRF (10(-11)-10(-8) M)-induced release of GH from AP cells was decreased in diabetic rats (maximum response to 10(-8) M GRF, 401 +/- 60 vs. 618 +/- 41 ng/10(5) cells; P less than 0.01); however, sensitivity to GRF was unchanged (EC50, 79 +/- 41 vs. 128 +/- 67 pM). By contrast, SRIF (10(-7)-10(-10)-induced inhibition of GRF (10(-8) M)-mediated GH release was impaired in AP cells of diabetic rats compared to that in controls (IC50, 112 +/- 33 vs. 55 +/- 31 pM; P less than 0.05) associated with a decrease in AP plasma membrane SRIF receptor concentration (63.4 +/- 15.6 vs. 160.3 +/- 13.7 fmol/mg protein; P less than 0.05), with no change in affinity. These findings are consistent with chronic exposure to increased hypothalamic SRIF influence. GH synthesis has been shown to be independent of SRIF regulation; however, insulin-like growth factor-I and GRF inhibit and stimulate GH synthesis, respectively. In diabetic rats insulin-like growth factor-I levels were decreased, appropriate to low GH status, in serum (290 +/- 66 vs. 1662 +/- 92 ng/ml; P less than 0.001) and hypothalamus (6.8 +/- 1.0 vs. 13.0 +/- 0.4 pg/mg wet wt; P less than 0.001) and, thus, did not seem to

  17. Aerobic glycolysis tunes YAP/TAZ transcriptional activity

    PubMed Central

    Enzo, Elena; Santinon, Giulia; Pocaterra, Arianna; Aragona, Mariaceleste; Bresolin, Silvia; Forcato, Mattia; Grifoni, Daniela; Pession, Annalisa; Zanconato, Francesca; Guzzo, Giulia; Bicciato, Silvio; Dupont, Sirio

    2015-01-01

    Increased glucose metabolism and reprogramming toward aerobic glycolysis are a hallmark of cancer cells, meeting their metabolic needs for sustained cell proliferation. Metabolic reprogramming is usually considered as a downstream consequence of tumor development and oncogene activation; growing evidence indicates, however, that metabolism on its turn can support oncogenic signaling to foster tumor malignancy. Here, we explored how glucose metabolism regulates gene transcription and found an unexpected link with YAP/TAZ, key transcription factors regulating organ growth, tumor cell proliferation and aggressiveness. When cells actively incorporate glucose and route it through glycolysis, YAP/TAZ are fully active; when glucose metabolism is blocked, or glycolysis is reduced, YAP/TAZ transcriptional activity is decreased. Accordingly, glycolysis is required to sustain YAP/TAZ pro-tumorigenic functions, and YAP/TAZ are required for the full deployment of glucose growth-promoting activity. Mechanistically we found that phosphofructokinase (PFK1), the enzyme regulating the first committed step of glycolysis, binds the YAP/TAZ transcriptional cofactors TEADs and promotes their functional and biochemical cooperation with YAP/TAZ. Strikingly, this regulation is conserved in Drosophila, where phosphofructokinase is required for tissue overgrowth promoted by Yki, the fly homologue of YAP. Moreover, gene expression regulated by glucose metabolism in breast cancer cells is strongly associated in a large dataset of primary human mammary tumors with YAP/TAZ activation and with the progression toward more advanced and malignant stages. These findings suggest that aerobic glycolysis endows cancer cells with particular metabolic properties and at the same time sustains transcription factors with potent pro-tumorigenic activities such as YAP/TAZ. PMID:25796446

  18. Hbr1 Activates and Represses Hyphal Growth in Candida albicans and Regulates Fungal Morphogenesis under Embedded Conditions

    PubMed Central

    Pendrak, Michael L.; Roberts, David D.

    2015-01-01

    Transitions between yeast and hyphae are essential for Candida albicans pathogenesis. The genetic programs that regulate its hyphal development can be distinguished by embedded versus aerobic surface agar invasion. Hbr1, a regulator of white-opaque switching, is also a positive and negative regulator of hyphal invasion. During embedded growth at 24°C, an HBR1/hbr1 strain formed constitutively filamentous colonies throughout the matrix, resembling EFG1 null colonies, and a subset of long unbranched hyphal aggregates enclosed in a spindle-shaped capsule. Inhibition of adenylate cyclase with farnesol perturbed the filamentation of HBR1/hbr1 cells producing cytokinesis-defective hyphae whereas farnesol treated EFG1 null cells produced abundant opaque-like cells. Point mutations in the Hbr1 ATP-binding domain caused distinct filamentation phenotypes including uniform radial hyphae, hyphal sprouts, and massive yeast cell production. Conversely, aerobic surface colonies of the HBR1 heterozygote on Spider and GlcNAc media lacked filamentation that could be rescued by growth under low (5%) O2. Consistent with these morphogenesis defects, the HBR1 heterozygote exhibited attenuated virulence in a mouse candidemia model. These data define Hbr1 as an ATP-dependent positive and negative regulator of hyphal development that is sensitive to hypoxia. PMID:26039220

  19. Heterotrophic ammonium removal characteristics of an aerobic heterotrophic nitrifying-denitrifying bacterium, Providencia rettgeri YL.

    PubMed

    Taylor, Shauna M; He, Yiliang; Zhao, Bin; Huang, Jue

    2009-01-01

    Bacterium Providencia rettgeri YL was found to exhibit an unusual ability to heterotrophically nitrify and aerobically denitrify various concentrations of ammonium (NH4+-N). In order to further understand its removal ability, several experiments were conducted to identify the growth and ammonium removal response at different carbon to nitrogen (C/N) mass ratios, shaking speeds, temperatures, ammonium concentrations and to qualitatively verify the production of nitrogen gas using gas chromatography techniques. Results showed that under optimum conditions (C/N 10, 30 degrees C, 120 r/min), YL can significantly remove low and high concentrations of ammonium within 12 to 48 h of growth, respectively. The nitrification products hydroxylamine (NH2OH), nitrite (NO2(-)) and nitrate (NO3(-)) as well as the denitrification product, nitrogen gas (N2), were detected under completely aerobic conditions. PMID:19999986

  20. Birth Defects Diagnosis

    MedlinePlus

    ... chromosomal disorder or heart defect in the baby. Second Trimester Screening Second trimester screening tests are completed between weeks 15 ... look for certain birth defects in the baby. Second trimester screening tests include a maternal serum screen ...

  1. Atrial septal defect

    MedlinePlus

    ... Coronary angiography (for patients over 35 years old) ECG Heart MRI Transesophageal echocardiography (TEE) Treatment ASD may ... of the complications can be prevented with early detection. Alternative Names Congenital heart defect - ASD; Birth defect ...

  2. Entorhinal volume, aerobic fitness, and recognition memory in healthy young adults: A voxel-based morphometry study.

    PubMed

    Whiteman, Andrew S; Young, Daniel E; Budson, Andrew E; Stern, Chantal E; Schon, Karin

    2016-02-01

    Converging evidence supports the hypothesis effects of aerobic exercise and environmental enrichment are beneficial for cognition, in particular for hippocampus-supported learning and memory. Recent work in humans suggests that exercise training induces changes in hippocampal volume, but it is not known if aerobic exercise and fitness also impact the entorhinal cortex. In animal models, aerobic exercise increases expression of growth factors, including brain derived neurotrophic factor (BDNF). This exercise-enhanced expression of growth hormones may boost synaptic plasticity, and neuronal survival and differentiation, potentially supporting function and structure in brain areas including but not limited to the hippocampus. Here, using voxel based morphometry and a standard graded treadmill test to determine cardio-respiratory fitness (Bruce protocol; ·VO2 max), we examined if entorhinal and hippocampal volumes were associated with cardio-respiratory fitness in healthy young adults (N=33). In addition, we examined if volumes were modulated by recognition memory performance and by serum BDNF, a putative marker of synaptic plasticity. Our results show a positive association between volume in right entorhinal cortex and cardio-respiratory fitness. In addition, average gray matter volume in the entorhinal cortex, bilaterally, was positively associated with memory performance. These data extend prior work on the cerebral effects of aerobic exercise and fitness to the entorhinal cortex in healthy young adults thus providing compelling evidence for a relationship between aerobic fitness and structure of the medial temporal lobe memory system. PMID:26631814

  3. Membrane biofouling mechanism in an aerobic granular reactor degrading 4-chlorophenol.

    PubMed

    Buitrón, Germán; Moreno-Andrade, Iván; Arellano-Badillo, Víctor M; Ramírez-Amaya, Víctor

    2014-01-01

    The membrane fouling of an aerobic granular reactor coupled with a submerged membrane in a sequencing batch reactor (SBR) was evaluated. The fouling analysis was performed by applying microscopy techniques to determine the morphology and structure of the fouling layer on a polyvinylidene fluoride membrane. It was found that the main cause of fouling was the polysaccharide adsorption on the membrane surface, followed by the growth of microorganisms to form a biofilm. PMID:24759539

  4. Binary Interactions of Antagonistic Bacteria with Candida albicans Under Aerobic and Anaerobic Conditions.

    PubMed

    Benadé, Eliska; Stone, Wendy; Mouton, Marnel; Postma, Ferdinand; Wilsenach, Jac; Botha, Alfred

    2016-04-01

    We used both aerobic and anaerobic liquid co-cultures, prepared with Luria Bertani broth, to study the effect of bacteria on the survival of Candida albicans in the external environment, away from an animal host. The bacteria were represented by Aeromonas hydrophila, Bacillus cereus, Bacillus subtilis, Clostridium, Enterobacter, Klebsiella pneumoniae, Kluyvera ascorbata and Serratia marcescens. Under aerobic conditions, the yeast's growth was inhibited in the presence of bacterial growth; however, under anaerobic conditions, yeast and bacterial growth in co-cultures was similar to that observed for pure cultures. Subsequent assays revealed that the majority of bacterial strains aerobically produced extracellular hydrolytic enzymes capable of yeast cell wall hydrolysis, including chitinases and mannan-degrading enzymes. In contrast, except for the A. hydrophila strain, these enzymes were not detected in anaerobic bacterial cultures, nor was the antimicrobial compound prodigiosin found in anaerobic cultures of S. marcescens. When we suspended C. albicans cells in crude extracellular enzyme preparations from K. pneumoniae and S. marcescens, we detected no negative effect on yeast viability. However, we found that these preparations enhance the toxicity of prodigiosin towards the yeast, especially in combination with mannan-degrading enzymes. Analyses of the chitin and mannan content of yeast cell walls revealed that less chitin was produced under anaerobic than aerobic conditions; however, the levels of mannan, known for its low permeability, remained the same. The latter phenomenon, as well as reduced production of the bacterial enzymes and prodigiosin, may contribute to anaerobic growth and survival of C. albicans in the presence of bacteria. PMID:26566932

  5. Effect of chlorate, molybdate, and shikimic acid on Salmonella Typhimurium in aerobic and anaerobic cultures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two studies were conducted to examine the effects of shikimic acid (60 µg/mL) and(or) molybdate (1 mM) on the sensitivity of Salmonella enterica serovar Typhimurium to sodium chlorate (5 mM) during anaerobic (90% N2:5% CO2:5% H2) or aerobic growth in brain heart infusion broth supplemented with 5 mM...

  6. Topological defects with long-range interactions

    NASA Astrophysics Data System (ADS)

    Mello, B. A.; González, J. A.; Guerrero, L. E.; López-Atencio, E.

    1998-07-01

    We investigate a modified sine-Gordon equation which possesses soliton solutions with long-range interaction. We introduce a generalized version of the Ginzburg-Landau equation which supports long-range topological defects in D = 1 and D > 1. The interaction force between the defects decays so slowly that it is possible to enter the non-extensivity regime. These results can be applied to non-equilibrium systems, pattern formation and growth models.

  7. InsP6-Sensitive Variants of the Gle1 mRNA Export Factor Rescue Growth and Fertility Defects of the ipk1 Low-Phytic-Acid Mutation in Arabidopsis

    PubMed Central

    Lee, Ho-Seok; Lee, Du-Hwa; Cho, Hui Kyung; Kim, Song Hee; Auh, Joong Hyuck; Pai, Hyun-Sook

    2015-01-01

    Myo-inositol-1,2,3,4,5,6-hexakisphosphate (InsP6), also known as phytic acid, accumulates in large quantities in plant seeds, serving as a phosphorus reservoir, but is an animal antinutrient and an important source of water pollution. Here, we report that Gle1 (GLFG lethal 1) in conjunction with InsP6 functions as an activator of the ATPase/RNA helicase LOS4 (low expression of osmotically responsive genes 4), which is involved in mRNA export in plants, supporting the Gle1-InsP6-Dbp5 (LOS4 homolog) paradigm proposed in yeast. Interestingly, plant Gle1 proteins have modifications in several key residues of the InsP6 binding pocket, which reduce the basicity of the surface charge. Arabidopsis thaliana Gle1 variants containing mutations that increase the basic charge of the InsP6 binding surface show increased sensitivity to InsP6 concentrations for the stimulation of LOS4 ATPase activity in vitro. Expression of the Gle1 variants with enhanced InsP6 sensitivity rescues the mRNA export defect of the ipk1 (inositol 1,3,4,5,6-pentakisphosphate 2-kinase) InsP6-deficient mutant and, furthermore, significantly improves vegetative growth, seed yield, and seed performance of the mutant. These results suggest that Gle1 is an important factor responsible for mediating InsP6 functions in plant growth and reproduction and that Gle1 variants with increased InsP6 sensitivity may be useful for engineering high-yielding low-phytate crops. PMID:25670768

  8. Facts about Birth Defects

    MedlinePlus

    ... Us Information For... Media Policy Makers Facts about Birth Defects Language: English Español (Spanish) Recommend on Facebook Tweet ... having a baby born without a birth defect. Birth Defects Are Common Every 4 ½ minutes, a baby ...

  9. Glycerol as a substrate for aerobic succinate production in minimal medium with Corynebacterium glutamicum

    PubMed Central

    Litsanov, Boris; Brocker, Melanie; Bott, Michael

    2013-01-01

    Corynebacterium glutamicum, an established microbial cell factory for the biotechnological production of amino acids, was recently genetically engineered for aerobic succinate production from glucose in minimal medium. In this work, the corresponding strains were transformed with plasmid pVWEx1-glpFKD coding for glycerol utilization genes from Escherichia coli. This plasmid had previously been shown to allow growth of C. glutamicum with glycerol as sole carbon source. The resulting strains were tested in minimal medium for aerobic succinate production from glycerol, which is a by-product in biodiesel synthesis. The best strain BL-1/pVWEx1-glpFKD formed 79 mM (9.3 g l−1) succinate from 375 mM glycerol, representing 42% of the maximal theoretical yield under aerobic conditions. A specific succinate production rate of 1.55 mmol g−1 (cdw) h−1 and a volumetric productivity of 3.59 mM h−1 were obtained, the latter value representing the highest one currently described in literature. The results demonstrate that metabolically engineered strains of C. glutamicum are well suited for aerobic succinate production from glycerol. PMID:22513227

  10. Aerobic granular sludge mediated biodegradation of an organophosphorous ester, dibutyl phosphite.

    PubMed

    Kiran Kumar Reddy, G; Nancharaiah, Yarlagadda Venkata; Venugopalan, Vayalam Purath

    2014-10-01

    Dibutyl phosphite, an organophosphorous compound, finds applications in different chemical industries and processes. Here, we report an efficient approach of biodegradation to be eventually used in bioremediation of dibutyl phosphite. Aerobic granules capable of dibutyl phosphite biodegradation were cultivated in a sequencing batch reactor (SBR). The SBR was operated with a 24-h cycle by feeding with dibutyl phosphite as a cosubstrate along with acetate. During the course of the SBR operation, aerobic granules of 0.9 ± 0.3 mm size were developed. Complete biodegradation of 1.4, 2 and 3 mM of dibutyl phosphite was achieved in 4, 5 and 8 h, respectively, accompanied by stoichiometric release of phosphite (H3 PO3). Phosphatase activity in the dibutyl phosphite-degrading granular biomass was 3- and 1.5-fold higher as compared to the activated sludge (seed biomass) and acetate-fed aerobic granules, respectively, indicating involvement in the hydrolysis of dibutyl phosphite. Microbial community analysis by t-RFLP showed the presence of 12 different bacterial types. Two bacterial strains capable of growth on dibutyl phosphite as sole carbon source were isolated and characterized as Acidovorax sp. and Sphingobium sp. The results show that aerobic microbial granules based process is suitable for the treatment of dibutyl phosphite contaminated water. PMID:25135363

  11. Detoxification of furfural in Corynebacterium glutamicum under aerobic and anaerobic conditions.

    PubMed

    Tsuge, Yota; Hori, Yoshimi; Kudou, Motonori; Ishii, Jun; Hasunuma, Tomohisa; Kondo, Akihiko

    2014-10-01

    The toxic fermentation inhibitors in lignocellulosic hydrolysates raise serious problems for the microbial production of fuels and chemicals. Furfural is considered to be one of the most toxic compounds among these inhibitors. Here, we describe the detoxification of furfural in Corynebacterium glutamicum ATCC13032 under both aerobic and anaerobic conditions. Under aerobic culture conditions, furfuryl alcohol and 2-furoic acid were produced as detoxification products of furfural. The ratio of the products varied depending on the initial furfural concentration. Neither furfuryl alcohol nor 2-furoic acid showed any toxic effect on cell growth, and both compounds were determined to be the end products of furfural degradation. Interestingly, unlike under aerobic conditions, most of the furfural was converted to furfuryl alcohol under anaerobic conditions, without affecting the glucose consumption rate. Both the NADH/NAD(+) and NADPH/NADP(+) ratio decreased in the accordance with furfural concentration under both aerobic and anaerobic conditions. These results indicate the presence of a single or multiple endogenous enzymes with broad and high affinity for furfural and co-factors in C. glutamicum ATCC13032. PMID:25112225

  12. Agricultural potential of anaerobically digested industrial orange waste with and without aerobic post-treatment.

    PubMed

    Kaparaju, Prasad; Rintala, Jukka; Oikari, Aimo

    2012-01-01

    The potential of anaerobically digested orange waste with (AAD) and without (AD) aerobic post-treatment for use in agriculture was evaluated through chemical analyses, short-term phytotoxicity and long-term plant assays. Chemical analyses showed that AD contained ammonia and organic acids, and aerobic post-treatment did not significantly remove these phytotoxins. The N:P2O5:K2O ratio in AD was 1:0.26:0.96 and aerobic post-treatment did not change the composition in AAD except for K2O (1:0.26:1.24). Heavy metal contents in AD and AAD were more or less the same and were below the upper limit recommended for non-sewage sludge application on agricultural soils. Short-term phytotoxicity tests showed that seed germination and root elongation of Chinese cabbage and ryegrass were severely inhibited at digestate concentrations of 60-100%. Germination index values were well below the score of 50% required to indicate the phytotoxic-free nature of compost. Long-term plant assays showed that AD and AAD, when supplemented with a base fertilizer, resulted in higher plant growth, and fresh weight and dry matter production than AD without base fertilizer. The results thus indicate that aerobic post-treatment did not have any significant beneficial effect on reducing phytotoxicity, and AD could be used as such on agricultural soils, especially with high P. PMID:22519091

  13. Aerobic workout and bone mass in females.

    PubMed

    Alfredson, H; Nordström, P; Lorentzon, R

    1997-12-01

    This cross-sectional study aimed to investigate bone mass in females participating in aerobic workout. Twenty-three females (age 24.1 +/- 2.7 years), participating in aerobic workout for about 3 hours/week, were compared with 23 age-, weight- and height-matched non-active females. Areal bone mineral density (BMD) was measured in total body, head, whole dominant humerus, lumbar spine, right femoral neck, Ward's triangle, trochanter femoris, in specific sites in right femur diaphysis, distal femur, proximal tibia and tibial diaphysis, and bone mineral content (BMC) was measured in the whole dominant arm and right leg, using dual energy X-ray absorptiometry. The aerobic workout group had significantly (P < 0.05-0.01) higher BMD in total body (3.7%), lumbar spine (7.8%), femoral neck (11.6%), Ward's triangle (11.7%), trochanter femoris (9.6%), proximal tibia (6.8%) and tibia diaphysis (5.9%) compared to the non-active controls. There were no differences between the groups concerning BMD of the whole dominant humerus, femoral diaphysis, distal femur and BMC and lean mass of the whole dominant arm and right leg. Leaness of the whole dominant arm and leg was correlated to BMC of the whole dominant arm and right leg in both groups. In young females, aerobic workout containing alternating high and low impact movements for the lower body is associated with a higher bone mass in clinically important sites like the lumbar spine and hip, but muscle strengthening exercises like push-ups and soft-glove boxing are not associated with a higher bone mass in the dominant humerus. It appears that there is a skeletal adaptation to the loads of the activity. PMID:9458499

  14. Nitrification and aerobic denitrification in anoxic-aerobic sequencing batch reactor.

    PubMed

    Alzate Marin, Juan C; Caravelli, Alejandro H; Zaritzky, Noemí E

    2016-01-01

    The aim of this study was to evaluate the feasibility of achieving nitrogen (N) removal using a lab-scale sequencing batch reactor (SBR) exposed to anoxic/aerobic (AN/OX) phases, focusing to achieve aerobic denitrification. This process will minimize emissions of N2O greenhouse gas. The effects of different operating parameters on the reactor performance were studied: cycle duration, AN/OX ratio, pH, dissolved oxygen concentration (DOC), and organic load. The highest inorganic N removal (NiR), close to 70%, was obtained at pH=7.5, low organic load (440mgCOD/(Lday)) and high aeration given by 12h cycle, AN/OX ratio=0.5:1.0 and DOC higher than 4.0mgO2/L. Nitrification followed by high-rate aerobic denitrification took place during the aerobic phase. Aerobic denitrification could be attributed to Tetrad-forming organisms (TFOs) with phenotype of glycogen accumulating organisms using polyhydroxyalkanoate and/or glycogen storage. The proposed AN/OX system constitutes an eco-friendly N removal process providing N2 as the end product. PMID:26512862

  15. Aerobic and two-stage anaerobic-aerobic sludge digestion with pure oxygen and air aeration.

    PubMed

    Zupancic, Gregor D; Ros, Milenko

    2008-01-01

    The degradability of excess activated sludge from a wastewater treatment plant was studied. The objective was establishing the degree of degradation using either air or pure oxygen at different temperatures. Sludge treated with pure oxygen was degraded at temperatures from 22 degrees C to 50 degrees C while samples treated with air were degraded between 32 degrees C and 65 degrees C. Using air, sludge is efficiently degraded at 37 degrees C and at 50-55 degrees C. With oxygen, sludge was most effectively degraded at 38 degrees C or at 25-30 degrees C. Two-stage anaerobic-aerobic processes were studied. The first anaerobic stage was always operated for 5 days HRT, and the second stage involved aeration with pure oxygen and an HRT between 5 and 10 days. Under these conditions, there is 53.5% VSS removal and 55.4% COD degradation at 15 days HRT - 5 days anaerobic, 10 days aerobic. Sludge digested with pure oxygen at 25 degrees C in a batch reactor converted 48% of sludge total Kjeldahl nitrogen to nitrate. Addition of an aerobic stage with pure oxygen aeration to the anaerobic digestion enhances ammonium nitrogen removal. In a two-stage anaerobic-aerobic sludge digestion process within 8 days HRT of the aerobic stage, the removal of ammonium nitrogen was 85%. PMID:17251012

  16. Defect production in ceramics

    SciTech Connect

    Zinkle, S.J.; Kinoshita, C.

    1997-08-01

    A review is given of several important defect production and accumulation parameters for irradiated ceramics. Materials covered in this review include alumina, magnesia, spinel silicon carbide, silicon nitride, aluminum nitride and diamond. Whereas threshold displacement energies for many ceramics are known within a reasonable level of uncertainty (with notable exceptions being AIN and Si{sub 3}N{sub 4}), relatively little information exists on the equally important parameters of surviving defect fraction (defect production efficiency) and point defect migration energies for most ceramics. Very little fundamental displacement damage information is available for nitride ceramics. The role of subthreshold irradiation on defect migration and microstructural evolution is also briefly discussed.

  17. Topological defect lasers

    NASA Astrophysics Data System (ADS)

    Knitter, Sebastian; Fatt Liew, Seng; Xiong, Wen; Guy, Mikhael I.; Solomon, Glenn S.; Cao, Hui

    2016-01-01

    We introduce a topological defect to a regular photonic crystal defect cavity with anisotropic unit cell. Spatially localized resonances are formed and have high quality factor. Unlike the regular photonic crystal defect states, the localized resonances in the topological defect structures support powerflow vortices. Experimentally we realize lasing in the topological defect cavities with optical pumping. This work shows that the spatially inhomogeneous variation of the unit cell orientation adds another degree of freedom to the control of lasing modes, enabling the manipulation of the field pattern and energy flow landscape.

  18. Studying post-etching silicon crystal defects on 300mm wafer by automatic defect review AFM

    NASA Astrophysics Data System (ADS)

    Zandiatashbar, Ardavan; Taylor, Patrick A.; Kim, Byong; Yoo, Young-kook; Lee, Keibock; Jo, Ahjin; Lee, Ju Suk; Cho, Sang-Joon; Park, Sang-il

    2016-03-01

    Single crystal silicon wafers are the fundamental elements of semiconductor manufacturing industry. The wafers produced by Czochralski (CZ) process are very high quality single crystalline materials with known defects that are formed during the crystal growth or modified by further processing. While defects can be unfavorable for yield for some manufactured electrical devices, a group of defects like oxide precipitates can have both positive and negative impacts on the final device. The spatial distribution of these defects may be found by scattering techniques. However, due to limitations of scattering (i.e. light wavelength), many crystal defects are either poorly classified or not detected. Therefore a high throughput and accurate characterization of their shape and dimension is essential for reviewing the defects and proper classification. While scanning electron microscopy (SEM) can provide high resolution twodimensional images, atomic force microscopy (AFM) is essential for obtaining three-dimensional information of the defects of interest (DOI) as it is known to provide the highest vertical resolution among all techniques [1]. However AFM's low throughput, limited tip life, and laborious efforts for locating the DOI have been the limitations of this technique for defect review for 300 mm wafers. To address these limitations of AFM, automatic defect review AFM has been introduced recently [2], and is utilized in this work for studying DOI on 300 mm silicon wafer. In this work, we carefully etched a 300 mm silicon wafer with a gaseous acid in a reducing atmosphere at a temperature and for a sufficient duration to decorate and grow the crystal defects to a size capable of being detected as light scattering defects [3]. The etched defects form a shallow structure and their distribution and relative size are inspected by laser light scattering (LLS). However, several groups of defects couldn't be properly sized by the LLS due to the very shallow depth and low

  19. Postdevelopment defect evaluation

    NASA Astrophysics Data System (ADS)

    Miyahara, Osamu; Kiba, Yukio; Ono, Yuko

    2001-08-01

    Reduction of defects after development is a critical issue in photolithography. A special category of post development defects is the satellite defect which is located in large exposed areas generally in proximity to large unexposed regions of photoresist. We have investigated the formation of this defect type on ESCAP and ACETAL DUV resists with and without underlying organic BARCs, In this paper, we will present AFM and elemental analysis data to determine the origin of the satellite defect. Imaging was done on a full-field Nikon 248nm stepper and resist processing was completed on a TEL CLEAN TRACK ACT 8 track. Defect inspection and review were performed on a KLA-Tencor and Hitachi SEM respectively. Results indicate that the satellite defect is generated on both BARC and resist films and defect counts are dependent on the dark erosion. Elemental analysis indicates that the defects are composed of sulfur and nitrogen compounds. We suspect that the defect is formed as a result of a reaction between PAG, quencher and TMAH. This defect type is removed after a DIW re-rinse.

  20. Transcriptomic and metabolomic profiling of Zymomonas mobilis during aerobic and anaerobic fermentations

    SciTech Connect

    Yang, Shihui; Tschaplinski, Timothy J; Engle, Nancy L; Carroll, Sue L; Martin, S L.; Davison, Brian H; Palumbo, Anthony Vito; Brown, Steven D

    2009-01-01

    Zymomonas mobilis ZM4 (ZM4) produces near theoretical yields of ethanol with high specific productivity and recombinant strains are able to ferment both C-5 and C-6 sugars. Z. mobilis performs best under anaerobic conditions, but is an aerotolerant organism. However, the genetic and physiological basis of ZM4's response to various stresses is understood poorly. In this study, transcriptomic and metabolomic profiles for ZM4 aerobic and anaerobic fermentations were elucidated by microarray analysis and by high-performance liquid chromatography (HPLC), gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) analyses. In the absence of oxygen, ZM4 consumed glucose more rapidly, had a higher growth rate, and ethanol was the major end-product. Greater amounts of other end-products such as acetate, lactate, and acetoin were detected under aerobic conditions and at 26 h there was only 1.7% of the amount of ethanol present aerobically as there was anaerobically. In the early exponential growth phase, significant differences in gene expression were not observed between aerobic and anaerobic conditions via microarray analysis. HPLC and GC analyses revealed minor differences in extracellular metabolite profiles at the corresponding early exponential phase time point. Differences in extracellular metabolite profiles between conditions became greater as the fermentations progressed. GC-MS analysis of stationary phase intracellular metabolites indicated that ZM4 contained lower levels of amino acids such as alanine, valine and lysine, and other metabolites like lactate, ribitol, and 4-hydroxybutanoate under anaerobic conditions relative to aerobic conditions. Stationary phase microarray analysis revealed that 166 genes were significantly differentially expressed by more than two-fold. Transcripts for Entner-Doudoroff (ED) pathway genes (glk, zwf, pgl, pgk, and eno) and gene pdc, encoding a key enzyme leading to ethanol production, were at least 30-fold more

  1. Aerobic Reduction of Arsenate by a Bacterium Isolated From Activated Sludge

    NASA Astrophysics Data System (ADS)

    Kozai, N.; Ohnuki, T.; Hanada, S.; Nakamura, K.; Francis, A. J.

    2006-12-01

    Microlunatus phosphovorus strain NM-1 is a polyphosphate-accumulating bacterium isolated from activated sludge. This bacterium takes up a large amount of polyphosphate under aerobic conditions and release phosphate ions by hydrolysis of polyphosphate to orthophosphate under anaerobic conditions to derive energy for taking up substrates. To understand the nature of this strain, especially, influence of potential contaminants in sewage and wastewater on growth, we have been investigating behavior of this bacterium in media containing arsenic. The present paper mainly reports reduction of arsenate by this bacterium under aerobic conditions. The strain NM-1 (JCM 9379) was aerobically cultured at 30 °C in a nutrient medium containing 2.5 g/l peptone, 0.5 g/l glucose, 1.5 g/l yeast extract, and arsenic [Na2HAsO4 (As(V)) or Na3AsO3 (As(III))] at concentrations between 0 and 50 mM. The cells collected from arsenic-free media were dispersed in buffer solutions containing 2mM HEPES, 10mM NaCl, prescribed concentrations of As(V), and 0-0.2 percent glucose. Then, this cell suspension was kept at 20 °C under aerobic or anaerobic conditions. The speciation of arsenic was carried out by ion chromatography and ICP-MS. The growth of the strain under aerobic conditions was enhanced by the addition of As(V) at the concentration between 1 and 10 mM. The maximum optical density of the culture in the medium containing 5mM As(V) was 1.4 times greater than that of the control culture. Below the As(V) concentration of 10mM, most of the As(V) was reduced to As(III). The growth of the strain under anaerobic conditions has not been observed so far. The cells in the buffer solutions reduced As(V) under aerobic condition. The reduction was enhanced by the addition of glucose. However, the cell did not reduce As(V) under anaerobic conditions. The strain NM-1 showed high resistance to As(V) and As(III). The maximum optical density of the culture grown in a medium containing 50 mM As(V) was only

  2. Transcriptomic and metabolomic profiling of Zymomonas mobilis during aerobic and anaerobic fermentations

    PubMed Central

    Yang, Shihui; Tschaplinski, Timothy J; Engle, Nancy L; Carroll, Sue L; Martin, Stanton L; Davison, Brian H; Palumbo, Anthony V; Rodriguez, Miguel; Brown, Steven D

    2009-01-01

    Background Zymomonas mobilis ZM4 (ZM4) produces near theoretical yields of ethanol with high specific productivity and recombinant strains are able to ferment both C-5 and C-6 sugars. Z. mobilis performs best under anaerobic conditions, but is an aerotolerant organism. However, the genetic and physiological basis of ZM4's response to various stresses is understood poorly. Results In this study, transcriptomic and metabolomic profiles for ZM4 aerobic and anaerobic fermentations were elucidated by microarray analysis and by high-performance liquid chromatography (HPLC), gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) analyses. In the absence of oxygen, ZM4 consumed glucose more rapidly, had a higher growth rate, and ethanol was the major end-product. Greater amounts of other end-products such as acetate, lactate, and acetoin were detected under aerobic conditions and at 26 h there was only 1.7% of the amount of ethanol present aerobically as there was anaerobically. In the early exponential growth phase, significant differences in gene expression were not observed between aerobic and anaerobic conditions via microarray analysis. HPLC and GC analyses revealed minor differences in extracellular metabolite profiles at the corresponding early exponential phase time point. Differences in extracellular metabolite profiles between conditions became greater as the fermentations progressed. GC-MS analysis of stationary phase intracellular metabolites indicated that ZM4 contained lower levels of amino acids such as alanine, valine and lysine, and other metabolites like lactate, ribitol, and 4-hydroxybutanoate under anaerobic conditions relative to aerobic conditions. Stationary phase microarray analysis revealed that 166 genes were significantly differentially expressed by more than two-fold. Transcripts for Entner-Doudoroff (ED) pathway genes (glk, zwf, pgl, pgk, and eno) and gene pdc, encoding a key enzyme leading to ethanol production, were at least

  3. Structural defects in crystalline silicon

    NASA Technical Reports Server (NTRS)

    Sirtl, E.

    1985-01-01

    The basic photovoltaic properties of a given crystalline silicon specimen seem to be governed by density and nature of two to three dimensional lattice defects. These are mainly generated by primary growth conditions as grain boundaries of more or less intrinsic character or second phase precipitates from supersaturated solutions of carbon or oxygen. Considerably high values of both solubility and diffusivity in connection with their abundance in common refractory material systems account for the predominance of the two particular elements. Unsaturated dislocations of different types very often can be seen as a consequence of the existence of more dimensional defects as described initially. The final performance of a solar cell is dependent of the concentration and distribution of recombination active centers in the different regions of this device. Typical representatives are fast diffusing transition metals in form of either single atoms or simple complexes. Their avoidance, annihilation, or removal is of great concern in different fields of electronic materials development.

  4. The emission of volatile compounds during the aerobic and the combined anaerobic/aerobic composting of biowaste

    NASA Astrophysics Data System (ADS)

    Smet, Erik; Van Langenhove, Herman; De Bo, Inge

    Two different biowaste composting techniques were compared with regard to their overall emission of volatile compounds during the active composting period. In the aerobic composting process, the biowaste was aerated during a 12-week period, while the combined anaerobic/aerobic composting process consisted of a sequence of a 3-week anaerobic digestion (phase I) and a 2-week aeration period (phase II). While the emission of volatiles during phase I of the combined anaerobic/aerobic composting process was measured in a full-scale composting plant, the aerobic stages of both composting techniques were performed in pilot-scale composting bins. Similar groups of volatile compounds were analysed in the biogas and the aerobic composting waste gases, being alcohols, carbonyl compounds, terpenes, esters, sulphur compounds and ethers. Predominance of alcohols (38% wt/wt of the cumulative emission) was observed in the exhaust air of the aerobic composting process, while predominance of terpenes (87%) and ammonia (93%) was observed in phases I and II of the combined anaerobic/aerobic composting process, respectively. In the aerobic composting process, 2-propanol, ethanol, acetone, limonene and ethyl acetate made up about 82% of the total volatile organic compounds (VOC)-emission. Next to this, the gas analysis during the aerobic composting process revealed a strong difference in emission profile as a function of time between different groups of volatiles. The total emission of VOC, NH 3 and H 2S during the aerobic composting process was 742 g ton -1 biowaste, while the total emission during phases I and II of the combined anaerobic/aerobic composting process was 236 and 44 g ton -1 biowaste, respectively. Taking into consideration the 99% removal efficiency of volatiles upon combustion of the biogas of phase I in the electricity generator, the combined anaerobic/aerobic composting process can be considered as an attractive alternative for aerobic biowaste composting because of

  5. The aerobic and anaerobic bacteriology of perirectal abscesses.

    PubMed Central

    Brook, I; Frazier, E H

    1997-01-01

    The microbiology of perirectal abscesses in 144 patients was studied. Aerobic or facultative bacteria only were isolated in 13 (9%) instances, anaerobic bacteria only were isolated in 27 (19%) instances, and mixed aerobic and anaerobic flora were isolated in 104 (72%) instances. A total of 325 anaerobic and 131 aerobic or facultative isolates were recovered (2.2 anaerobic isolates and 0.9 aerobic isolates per specimen). The predominant anaerobes were as follows: Bacteroides fragilis group (85 isolates), Peptostreptococcus spp. (72 isolates), Prevotella spp. (71 isolates), Fusobacterium spp. (21 isolates), Porphyromonas spp. (20 isolates), and Clostridium spp. (15 isolates). The predominant aerobic and facultative bacteria were as follows: Staphylococcus aureus (34 isolates), Streptococcus spp. (28 isolates), and Escherichia coli (19 isolates). These data illustrate the polymicrobial aerobic and anaerobic microbiology of perirectal abscesses. PMID:9350771

  6. Intracellular azo decolorization is coupled with aerobic respiration by a Klebsiella oxytoca strain.

    PubMed

    Yu, Lei; Zhang, Xiao-Yu; Xie, Tian; Hu, Jin-Mei; Wang, Shi; Li, Wen-Wei

    2015-03-01

    Reduction of azo dye methyl red coupled with aerobic respiration by growing cultures of Klebsiella oxytoca GS-4-08 was investigated. In liquid media containing dye and 0.6 % glucose in a mineral salts base, 100 mg l(-1) of the dye are completely removed in 3 h under shaking conditions. The dye cannot be aerobically decolorized by strain GS-4-08 without extra carbon sources, indicating a co-metabolism process. Higher initial dye concentration prolonged the lag phase of the cell growth, but final cell concentrations of each batches reached a same level with range from 6.3 to 7.6 mg l(-1) after the dye adaption period. This strain showed stronger dye tolerance and decolorization ability than many reported strains. Furthermore, a new intracellular oxygen-insensitive azoreductase was isolated from this strain, and the specific activity of enzyme was 0.846 and 0.633 U mg(-1) protein in the presence of NADH and NADPH, respectively. N,N dimethyl-p-phenylenediamine and anthranilic acid were stoichiometrically released from MR dye, indicating the breakage of azo bonds accounts for the intracellular decolorization. Combining the characteristics of azoreductase, the stoichiometry of EMP, and TCA cycle, the electron transfer chain theory of aerobic respiration, and the possible mechanism of aerobic respiration coupled with azo reduction by K. oxytoca GS-4-08 are proposed. This study is expected to provide a sound theoretical basis for the development of the K. oxytoca strain in aerobic process for azo dye containing wastewaters. PMID:25343980

  7. Aerobic exercise improves cognition for older adults with glucose intolerance, a risk factor for Alzheimer's disease.

    PubMed

    Baker, Laura D; Frank, Laura L; Foster-Schubert, Karen; Green, Pattie S; Wilkinson, Charles W; McTiernan, Anne; Cholerton, Brenna A; Plymate, Stephen R; Fishel, Mark A; Watson, G Stennis; Duncan, Glen E; Mehta, Pankaj D; Craft, Suzanne

    2010-01-01

    Impaired glucose regulation is a defining characteristic of type 2 diabetes mellitus (T2DM) pathology and has been linked to increased risk of cognitive impairment and dementia. Although the benefits of aerobic exercise for physical health are well-documented, exercise effects on cognition have not been examined for older adults with poor glucose regulation associated with prediabetes and early T2DM. Using a randomized controlled design, twenty-eight adults (57-83 y old) meeting 2-h tolerance test criteria for glucose intolerance completed 6 months of aerobic exercise or stretching, which served as the control. The primary cognitive outcomes included measures of executive function (Trails B, Task Switching, Stroop, Self-ordered Pointing Test, and Verbal Fluency). Other outcomes included memory performance (Story Recall, List Learning), measures of cardiorespiratory fitness obtained via maximal-graded exercise treadmill test, glucose disposal during hyperinsulinemic-euglycemic clamp, body fat, and fasting plasma levels of insulin, cortisol, brain-derived neurotrophic factor, insulin-like growth factor-1, amyloid-β (Aβ40 and Aβ42). Six months of aerobic exercise improved executive function (MANCOVA, p=0.04), cardiorespiratory fitness (MANOVA, p=0.03), and insulin sensitivity (p=0.05). Across all subjects, 6-month changes in cardiorespiratory fitness and insulin sensitivity were positively correlated (p=0.01). For Aβ42, plasma levels tended to decrease for the aerobic group relative to controls (p=0.07). The results of our study using rigorous controlled methodology suggest a cognition-enhancing effect of aerobic exercise for older glucose intolerant adults. Although replication in a larger sample is needed, our findings potentially have important therapeutic implications for a growing number of adults at increased risk of cognitive decline. PMID:20847403

  8. Impact of salinity on the aerobic metabolism of phosphate-accumulating organisms.

    PubMed

    Welles, L; Lopez-Vazquez, C M; Hooijmans, C M; van Loosdrecht, M C M; Brdjanovic, D

    2015-04-01

    The use of saline water in urban areas for non-potable purposes to cope with fresh water scarcity, intrusion of saline water, and disposal of industrial saline wastewater into the sewerage lead to elevated salinity levels in wastewaters. Consequently, saline wastewater is generated, which needs to be treated before its discharge into surface water bodies. The objective of this research was to study the effects of salinity on the aerobic metabolism of phosphate-accumulating organisms (PAO), which belong to the microbial populations responsible for enhanced biological phosphorus removal (EBPR) in activated sludge systems. In this study, the short-term impact (hours) of salinity (as NaCl) was assessed on the aerobic metabolism of a PAO culture, enriched in a sequencing batch reactor (SBR). All aerobic PAO metabolic processes were drastically affected by elevated salinity concentrations. The aerobic maintenance energy requirement increased, when the salinity concentration rose up to a threshold concentration of 2 % salinity (on a W/V basis as NaCl), while above this concentration, the maintenance energy requirements seemed to decrease. All initial rates were affected by salinity, with the NH4- and PO4-uptake rates being the most sensitive. A salinity increase from 0 to 0.18 % caused a 25, 46, and 63 % inhibition of the O2, PO4, and NH4-uptake rates. The stoichiometric ratios of the aerobic conversions confirmed that growth was the process with the highest inhibition, followed by poly-P and glycogen formation. The study indicates that shock loads of 0.18 % salt, which corresponds to the use or intrusion of about 5 % seawater may severely affect the EBPR process already in wastewater treatment plants not exposed regularly to high salinity concentrations. PMID:25524698

  9. Evaluating printability of buried native EUV mask phase defects through a modeling and simulation approach

    NASA Astrophysics Data System (ADS)

    Upadhyaya, Mihir; Jindal, Vibhu; Basavalingappa, Adarsh; Herbol, Henry; Harris-Jones, Jenah; Jang, Il-Yong; Goldberg, Kenneth A.; Mochi, Iacopo; Marokkey, Sajan; Demmerle, Wolfgang; Pistor, Thomas V.; Denbeaux, Gregory

    2015-03-01

    The availability of defect-free masks is considered to be a critical issue for enabling extreme ultraviolet lithography (EUVL) as the next generation technology. Since completely defect-free masks will be hard to achieve, it is essential to have a good understanding of the printability of the native EUV mask defects. In this work, we performed a systematic study of native mask defects to understand the defect printability caused by them. The multilayer growth over native substrate mask blank defects was correlated to the multilayer growth over regular-shaped defects having similar profiles in terms of their width and height. To model the multilayer growth over the defects, a novel level-set multilayer growth model was used that took into account the tool deposition conditions of the Veeco Nexus ion beam deposition tool. The same tool was used for performing the actual deposition of the multilayer stack over the characterized native defects, thus ensuring a fair comparison between the actual multilayer growth over native defects, and modeled multilayer growth over regular-shaped defects. Further, the printability of the characterized native defects was studied with the SEMATECH-Berkeley Actinic Inspection Tool (AIT), an EUV mask-imaging microscope at Lawrence Berkeley National Laboratory (LBNL). Printability of the modeled regular-shaped defects, which were propagated up the multilayer stack using level-set growth model was studied using defect printability simulations implementing the waveguide algorithm. Good comparison was observed between AIT and the simulation results, thus demonstrating that multilayer growth over a defect is primarily a function of a defect's width and height, irrespective of its shape. This would allow us to predict printability of the arbitrarily-shaped native EUV mask defects in a systematic and robust manner.

  10. Depletion of Butyrate-Producing Clostridia from the Gut Microbiota Drives an Aerobic Luminal Expansion of Salmonella.

    PubMed

    Rivera-Chávez, Fabian; Zhang, Lillian F; Faber, Franziska; Lopez, Christopher A; Byndloss, Mariana X; Olsan, Erin E; Xu, Gege; Velazquez, Eric M; Lebrilla, Carlito B; Winter, Sebastian E; Bäumler, Andreas J

    2016-04-13

    The mammalian intestine is host to a microbial community that prevents pathogen expansion through unknown mechanisms, while antibiotic treatment can increase susceptibility to enteric pathogens. Here we show that streptomycin treatment depleted commensal, butyrate-producing Clostridia from the mouse intestinal lumen, leading to decreased butyrate levels, increased epithelial oxygenation, and aerobic expansion of Salmonella enterica serovar Typhimurium. Epithelial hypoxia and Salmonella restriction could be restored by tributyrin treatment. Clostridia depletion and aerobic Salmonella expansion were also observed in the absence of streptomycin treatment in genetically resistant mice but proceeded with slower kinetics and required the presence of functional Salmonella type III secretion systems. The Salmonella cytochrome bd-II oxidase synergized with nitrate reductases to drive luminal expansion, and both were required for fecal-oral transmission. We conclude that Salmonella virulence factors and antibiotic treatment promote pathogen expansion through the same mechanism: depletion of butyrate-producing Clostridia to elevate epithelial oxygenation, allowing aerobic Salmonella growth. PMID:27078066

  11. Aerobic Microbial Cometabolism of Benzothiophene and 3-Methylbenzothiophene

    PubMed Central

    Fedorak, Phillip M.; Grbić-Galić, Dunja

    1991-01-01

    A culture enriched by growth on 1-methylnaphthalene was used to study the aerobic biotransformations of benzothiophene and 3-methylbenzothiophene. Neither of the sulfur heterocyclic compounds would support growth, but they were transformed by the culture growing on 1-methylnaphthalene or glucose or peptone. Cometabolism of benzothiophene yielded benzothiophene-2,3-dione, whereas that of 3-methylbenzothiophene yielded 3-methylbenzothiophene sulfoxide and the corresponding sulfone. The identities of the dione and sulfone were verified by comparison with authentic standards. The identity of the sulfoxide was surmised from gas chromatography-mass spectrometry and gas chromatography- Fourier transform infrared spectroscopy results. Oxidation preferentially occurred at carbons 2 and 3 in benzothiophene, but when carbon 3 was substituted with a methyl group, as in 3-methylbenzothiophene, the sulfur atom was oxygenated. The predominant microorganism in the enrichment culture was a Pseudomonas strain, designated BT1, which mineralized aromatic but not aliphatic hydrocarbons. This isolate cometabolized benzothiophene and 3-methylbenzothiophene. There was no evidence that it could metabolize 3-methylbenzothiophene sulfone. When 3-methylbenzothiophene was added to Prudhoe Bay crude oil, the sulfur heterocycle was oxidized to its sulfoxide and sulfone by strain BT1 as it grew on the aromatic hydrocarbons in the crude oil. Benzothiophene-2,3-dione was found to be chemically unstable when incubated with Prudhoe Bay crude oil. Thus its formation from benzothiophene in the presence of crude oil could not be determined. PMID:16348471

  12. Clinical comparison of the isolator and BacT/Alert aerobic blood culture systems.

    PubMed Central

    Hellinger, W C; Cawley, J J; Alvarez, S; Hogan, S F; Harmsen, W S; Ilstrup, D M; Cockerill, F R

    1995-01-01

    The performance characteristics of the Isolator (Wampole Laboratories, Cranbury, N.J.) and the BacT/Alert (Organon Teknika Corporation, Durham, N.C.) aerobic blood culture systems were compared for 6,009 blood culture sets obtained from patients with suspected bloodstream infections. The BacT/Alert aerobic bottle [BTA(O2)] was continuously agitated while it was incubated in 5% CO2 at 36 degrees C; culture plates prepared from the Isolator tube [I(O2)] were incubated in 5% CO2 at 37 degrees C. From 394 blood cultures, 416 clinically significant isolates of bacteria and yeasts were recovered. The overall yields for BTA(O2) and I(O2) were not significantly different (319 versus 336; P = 0.20). I(O2) recovered significantly more staphylococcus (P < 0.05) and yeast isolates (P < 0.01). BTA(O2) recovered significantly more aerobic and facultatively anaerobic gram-negative bacilli (P < 0.05). In blood culture sets which produced growth of the same organisms in both the BTA(O2) and I(O2) systems, the BTA(O2) system detected growth sooner, but more rapid identification was possible with the I(O2) system by virtue of earlier isolation of colonies on solid media. PMID:7665647

  13. Intrinsic structural defects in monolayer molybdenum disulfide

    SciTech Connect

    Zhou, Wu; Idrobo Tapia, Juan C

    2013-01-01

    Monolayer molybdenum disulfide (MoS2) is a two-dimensional direct band gap semiconductor with distinctive mechanical, electronic, optical and chemical properties that can be utilized for novel nanoelectronics and optoelectronics devices. The performance of these electronic devices strongly depends on the quality and defect morphology of the MoS2 layers. Yet, little is known about the atomic structure of defects present in monolayer MoS2 and their influences on the material properties. Here we provide a systematic study of various intrinsic structural defects, including point defects, grain boundaries, and edges, in chemical vapor phase grown monolayer MoS2 via direct atomic resolution imaging, and explore their energy landscape and electronic properties using first-principles calculations. We discover that one-dimensional metallic wires can be created via two different types of 60 grain boundaries consisting of distinct 4-fold ring chains. A new type of edge reconstruction, representing a transition state during growth, was also identified, providing insights into the material growth mechanism. The atomic scale study of structural defects presented here brings new opportunities to tailor the properties of MoS2 via controlled synthesis and defect engineering.

  14. Involvement of Linear Plasmids in Aerobic Biodegradation of Vinyl Chloride

    SciTech Connect

    BRIGMON, ROBINL.

    2004-06-14

    Pseudomonas putida strain AJ and Ochrobactrum strain TD were isolated from hazardous waste sites based on their ability to use vinyl chloride (VC) as a sole source of carbon and energy under aerobic conditions. Strains AJ and TD also use ethene and ethylene oxide as growth substrates. Strain AJ contained a linear megaplasmid (approximately 260 kb) when grown on VC or ethene, but no circular plasmids. While growing on ethylene oxide, the size of the linear plasmid in strain AJ decreased to approximately 100 kb, although its ability to use VC as a substrate was retained. The linear plasmids in strain AJ were cured and its ability to consume VC, ethene, and ethylene oxide was lost following growth on a rich substrate (Luria-Bertani broth) through at least three transfers. Strain TD contained three linear plasmids, ranging in size from approximately 100 kb to 320 kb, when growing on VC or ethene. As with strain AJ, the linear plasmids in strain TD were cured following growth on Luria -Bertani broth and its ability to consume VC and ethene was lost. Further analysis of these linear plasmids may help reveal the pathway for VC biodegradation in strains AJ and TD and explain why this process occurs at many but not all sites where groundwater is contaminated with chloroethenes. Metabolism of VC and ethene by strains AJ and TD is initiated by an alkene monooxygenase. Their yields during growth on VC (0.15-0.20 mg total suspended solids per mg VC) are similar to the yields reported for other isolates i.e., Mycobacterium sp., Nocardioides sp., and Pseudomonas sp.

  15. Aerobic degradation of olive mill wastewaters.

    PubMed

    Benitez, J; Beltran-Heredia, J; Torregrosa, J; Acero, J L; Cercas, V

    1997-02-01

    The degradation of olive mill wastewater by aerobic microorganisms has been investigated in a batch reactor, by conducting experiments where the initial concentration of organic matter, quantified by the chemical oxygen demand, and the initial biomass were varied. The evolution of the chemical oxygen demand, biomass and the total contents of phenolic and aromatic compounds were followed through each experiment. According to the Contois model, a kinetic expression for the substrate utilization rate is derived, and its biokinetic constants are evaluated. This final predicted equation agrees well with all the experimental data. PMID:9077005

  16. Platelet rich fibrin in jaw defects

    NASA Astrophysics Data System (ADS)

    Nica, Diana; Ianes, Emilia; Pricop, Marius

    2016-03-01

    Platelet rich fibrin (PRF) is a tissue product of autologous origin abundant in growth factors, widely used in regenerative procedures. Aim of the study: Evaluation of the regenerative effect of PRF added in the bony defects (after tooth removal or after cystectomy) Material and methods: The comparative nonrandomized study included 22 patients divided into 2 groups. The first group (the test group) included 10 patients where the bony defects were treated without any harvesting material. The second group included 12 patients where the bony defects were filled with PRF. The bony defect design was not critical, with one to two walls missing. After the surgeries, a close clinically monitoring was carried out. The selected cases were investigated using both cone beam computer tomography (CBCT) and radiographic techniques after 10 weeks postoperatively. Results: Faster bone regeneration was observed in the bony defects filled with PRF comparing with the not grafted bony defects. Conclusions: PRF added in the bony defects accelerates the bone regeneration. This simplifies the surgical procedures and decreases the economic costs.

  17. Exploring atomic defects in molybdenum disulphide monolayers

    PubMed Central

    Hong, Jinhua; Hu, Zhixin; Probert, Matt; Li, Kun; Lv, Danhui; Yang, Xinan; Gu, Lin; Mao, Nannan; Feng, Qingliang; Xie, Liming; Zhang, Jin; Wu, Dianzhong; Zhang, Zhiyong; Jin, Chuanhong; Ji, Wei; Zhang, Xixiang; Yuan, Jun; Zhang, Ze

    2015-01-01

    Defects usually play an important role in tailoring various properties of two-dimensional materials. Defects in two-dimensional monolayer molybdenum disulphide may be responsible for large variation of electric and optical properties. Here we present a comprehensive joint experiment–theory investigation of point defects in monolayer molybdenum disulphide prepared by mechanical exfoliation, physical and chemical vapour deposition. Defect species are systematically identified and their concentrations determined by aberration-corrected scanning transmission electron microscopy, and also studied by ab-initio calculation. Defect density up to 3.5 × 1013 cm−2 is found and the dominant category of defects changes from sulphur vacancy in mechanical exfoliation and chemical vapour deposition samples to molybdenum antisite in physical vapour deposition samples. Influence of defects on electronic structure and charge-carrier mobility are predicted by calculation and observed by electric transport measurement. In light of these results, the growth of ultra-high-quality monolayer molybdenum disulphide appears a primary task for the community pursuing high-performance electronic devices. PMID:25695374

  18. Exploring atomic defects in molybdenum disulphide monolayers.

    PubMed

    Hong, Jinhua; Hu, Zhixin; Probert, Matt; Li, Kun; Lv, Danhui; Yang, Xinan; Gu, Lin; Mao, Nannan; Feng, Qingliang; Xie, Liming; Zhang, Jin; Wu, Dianzhong; Zhang, Zhiyong; Jin, Chuanhong; Ji, Wei; Zhang, Xixiang; Yuan, Jun; Zhang, Ze

    2015-01-01

    Defects usually play an important role in tailoring various properties of two-dimensional materials. Defects in two-dimensional monolayer molybdenum disulphide may be responsible for large variation of electric and optical properties. Here we present a comprehensive joint experiment-theory investigation of point defects in monolayer molybdenum disulphide prepared by mechanical exfoliation, physical and chemical vapour deposition. Defect species are systematically identified and their concentrations determined by aberration-corrected scanning transmission electron microscopy, and also studied by ab-initio calculation. Defect density up to 3.5 × 10(13) cm(-2) is found and the dominant category of defects changes from sulphur vacancy in mechanical exfoliation and chemical vapour deposition samples to molybdenum antisite in physical vapour deposition samples. Influence of defects on electronic structure and charge-carrier mobility are predicted by calculation and observed by electric transport measurement. In light of these results, the growth of ultra-high-quality monolayer molybdenum disulphide appears a primary task for the community pursuing high-performance electronic devices. PMID:25695374

  19. Phylogenetic and Kinetic Diversity of Aerobic Vinyl Chloride-Assimilating Bacteria from Contaminated Sites

    PubMed Central

    Coleman, Nicholas V.; Mattes, Timothy E.; Gossett, James M.; Spain, Jim C.

    2002-01-01

    Aerobic bacteria that grow on vinyl chloride (VC) have been isolated previously, but their diversity and distribution are largely unknown. It is also unclear whether such bacteria contribute to the natural attenuation of VC at chlorinated-ethene-contaminated sites. We detected aerobic VC biodegradation in 23 of 37 microcosms and enrichments inoculated with samples from various sites. Twelve different bacteria (11 Mycobacterium strains and 1 Nocardioides strain) capable of growth on VC as the sole carbon source were isolated, and 5 representative strains were examined further. All the isolates grew on ethene in addition to VC and contained VC-inducible ethene monooxygenase activity. The Mycobacterium strains (JS60, JS61, JS616, and JS617) all had similar growth yields (5.4 to 6.6 g of protein/mol), maximum specific growth rates (0.17 to 0.23 day−1), and maximum specific substrate utilization rates (9 to 16 nmol/min/mg of protein) with VC. The Nocardioides strain (JS614) had a higher growth yield (10.3 g of protein/mol), growth rate (0.71 day−1), and substrate utilization rate (43 nmol/min/mg of protein) with VC but was much more sensitive to VC starvation. Half-velocity constant (Ks) values for VC were between 0.5 and 3.2 μM, while Ks values for oxygen ranged from 0.03 to 0.3 mg/liter. Our results indicate that aerobic VC-degrading microorganisms (predominantly Mycobacterium strains) are widely distributed at sites contaminated with chlorinated solvents and are likely to be responsible for the natural attenuation of VC. PMID:12450841

  20. Aerobic carboxydotrophy under extremely haloalkaline conditions in Alkalispirillum/Alkalilimnicola strains isolated from soda lakes.

    PubMed

    Sorokin, Dimitry Yu; Tourova, Tatjana P; Kovaleva, Olga L; Kuenen, J Gijs; Muyzer, Gerard

    2010-03-01

    Aerobic enrichments from soda lake sediments with CO as the only substrate resulted in the isolation of five bacterial strains capable of autotrophic growth with CO at extremely high pH and salinity. The strains belonged to the Alkalispirillum/Alkalilimnicola cluster in the Gammaproteobacteria, where the ability to oxidize CO, but not growth with CO, has been demonstrated previously. The growth with CO was possible only at an oxygen concentration below 5 % and CO concentration below 20 % in the gas phase. The isolates were also capable of growth with formate but not with H(2). The carboxydotrophic growth occurred within a narrow pH range from 8 to 10.5 (optimum at 9.5) and a broad salt concentration from 0.3 to 3.5 M total Na(+) (optimum at 1.0 M). Cells grown on CO had high respiration activity with CO and formate, while the cells grown on formate actively oxidized formate alone. In CO-grown cells, CO-dehydrogenase (CODH) activity was detectable both in soluble and membrane fractions, while the NAD-independent formate dehydrogenase (FDH) resided solely in membranes. The results of total protein profiling and the failure to detect CODH with conventional primers for the coxL gene indicated that the CO-oxidizing enzyme in haloalkaliphilic isolates might differ from the classical aerobic CODH complex. A single cbbL gene encoding the RuBisCO large subunit was detected in all strains, suggesting the presence of the Calvin cycle of inorganic carbon fixation. Overall, these results demonstrated the possibility of aerobic carboxydotrophy under extremely haloalkaline conditions. PMID:19959573

  1. Aerobic Stability and Effects of Yeasts during Deterioration of Non-fermented and Fermented Total Mixed Ration with Different Moisture Levels

    PubMed Central

    Hao, W.; Wang, H. L.; Ning, T. T.; Yang, F. Y.; Xu, C. C.

    2015-01-01

    The present experiment evaluated the influence of moisture level and anaerobic fermentation on aerobic stability of total mixed ration (TMR). The dynamic changes in chemical composition and microbial population that occur after air exposure were examined, and the species of yeast associated with the deterioration process were also identified in both non-fermented and fermented TMR to deepen the understanding of aerobic deterioration. The moisture levels of TMR in this experiment were adjusted to 400 g/kg (low moisture level, LML), 450 g/kg (medium moisture level, MML), and 500 g/kg (high moisture level, HML), and both non-fermented and 56-d-fermented TMR were subjected to air exposure to determine aerobic stability. Aerobic deterioration resulted in high losses of nutritional components and largely reduced dry matter digestibility. Non-fermented TMR deteriorated during 48 h of air exposure and the HML treatment was more aerobically unstable. On dry matter (DM) basis, yeast populations significantly increased from 107 to 1010 cfu/g during air exposure, and Candida ethanolica was the predominant species during deterioration in non-fermented TMR. Fermented TMR exhibited considerable resistance to aerobic deterioration. Spoilage was only observed in the HML treatment and its yeast population increased dramatically to 109 cfu/g DM when air exposure progressed to 30 d. Zygosaccharomyces bailii was the sole yeast species isolated when spoilage occurred. These results confirmed that non-fermented and fermented TMR with a HML are more prone to spoilage, and fermented TMR has considerable resistance to aerobic deterioration. Yeasts can trigger aerobic deterioration in both non-fermented and fermented TMR. C. ethanolica may be involved in the spoilage of non-fermented TMR and the vigorous growth of Z. bailii can initiate aerobic deterioration in fermented TMR. PMID:25925059

  2. Evaluating Printability of Buried Native EUV Mask Phase Defects through a Modeling and Simulation Approach

    SciTech Connect

    Upadhyaya, Mihir; Jindal, Vibhu; Basavalingappa, Adarsh; Herbol, Henry; Harris-Jones, Jenah; Jang, Il-Yong; Goldberg, Kenneth A.; Mochi, Iacopo; Marokkey, Sajan; Demmerle, Wolfgang; Pistor, Thomas V.; Denbeaux, Gregory

    2015-03-16

    The availability of defect-free masks is considered to be a critical issue for enabling extreme ultraviolet lithography (EUVL) as the next generation technology. Since completely defect-free masks will be hard to achieve, it is essential to have a good understanding of the printability of the native EUV mask defects. In this work, we performed a systematic study of native mask defects to understand the defect printability caused by them. The multilayer growth over native substrate mask blank defects was correlated to the multilayer growth over regular-shaped defects having similar profiles in terms of their width and height. To model the multilayer growth over the defects, a novel level-set multilayer growth model was used that took into account the tool deposition conditions of the Veeco Nexus ion beam deposition tool. The same tool was used for performing the actual deposition of the multilayer stack over the characterized native defects, thus ensuring a fair comparison between the actual multilayer growth over native defects, and modeled multilayer growth over regular-shaped defects. Further, the printability of the characterized native defects was studied with the SEMATECH-Berkeley Actinic Inspection Tool (AIT), an EUV mask-imaging microscope at Lawrence Berkeley National Laboratory (LBNL). Printability of the modeled regular-shaped defects, which were propagated up the multilayer stack using level-set growth model was studied using defect printability simulations implementing the waveguide algorithm. Good comparison was observed between AIT and the simulation results, thus demonstrating that multilayer growth over a defect is primarily a function of a defect’s width and height, irrespective of its shape. This would allow us to predict printability of the arbitrarily-shaped native EUV mask defects in a systematic and robust manner.

  3. Acute effects of aerobic exercise promote learning.

    PubMed

    Perini, Renza; Bortoletto, Marta; Capogrosso, Michela; Fertonani, Anna; Miniussi, Carlo

    2016-01-01

    The benefits that physical exercise confers on cardiovascular health are well known, whereas the notion that physical exercise can also improve cognitive performance has only recently begun to be explored and has thus far yielded only controversial results. In the present study, we used a sample of young male subjects to test the effects that a single bout of aerobic exercise has on learning. Two tasks were run: the first was an orientation discrimination task involving the primary visual cortex, and the second was a simple thumb abduction motor task that relies on the primary motor cortex. Forty-four and forty volunteers participated in the first and second experiments, respectively. We found that a single bout of aerobic exercise can significantly facilitate learning mechanisms within visual and motor domains and that these positive effects can persist for at least 30 minutes following exercise. This finding suggests that physical activity, at least of moderate intensity, might promote brain plasticity. By combining physical activity-induced plasticity with specific cognitive training-induced plasticity, we favour a gradual up-regulation of a functional network due to a steady increase in synaptic strength, promoting associative Hebbian-like plasticity. PMID:27146330

  4. Acute effects of aerobic exercise promote learning

    PubMed Central

    Perini, Renza; Bortoletto, Marta; Capogrosso, Michela; Fertonani, Anna; Miniussi, Carlo

    2016-01-01

    The benefits that physical exercise confers on cardiovascular health are well known, whereas the notion that physical exercise can also improve cognitive performance has only recently begun to be explored and has thus far yielded only controversial results. In the present study, we used a sample of young male subjects to test the effects that a single bout of aerobic exercise has on learning. Two tasks were run: the first was an orientation discrimination task involving the primary visual cortex, and the second was a simple thumb abduction motor task that relies on the primary motor cortex. Forty-four and forty volunteers participated in the first and second experiments, respectively. We found that a single bout of aerobic exercise can significantly facilitate learning mechanisms within visual and motor domains and that these positive effects can persist for at least 30 minutes following exercise. This finding suggests that physical activity, at least of moderate intensity, might promote brain plasticity. By combining physical activity–induced plasticity with specific cognitive training–induced plasticity, we favour a gradual up-regulation of a functional network due to a steady increase in synaptic strength, promoting associative Hebbian-like plasticity. PMID:27146330

  5. Defect mode properties of two-dimensional plasma-filled defective metallic photonic crystal

    SciTech Connect

    Fu, T.; Yang, Z.; Tang, X.; Shi, Z.; Lan, F.

    2014-01-15

    This paper studies the frequency and amplitude properties of a defect mode which is only in a plasma-filled metallic photonic crystal with defect layer. Results show that the frequency almost has no change and the amplitude declines gradually with the growth of the number of the layers. The frequency of the defect mode not only can be modulated by filling ratio but also can be tuned by plasma density without modifying the structure. The amplitude can be modified by plasma angular frequency as well. These characteristics provide a foundation to design tunable filters, high power millimeter devices.

  6. Construction of Radial Defect Models in Rabbits to Determine the Critical Size Defects

    PubMed Central

    Zhang, Xin-Chao; Gui, Ke-Ke; Xiong, Min; Yin, Wang-Ping; Yuan, Feng-Lai; Cai, Guo-Ping

    2016-01-01

    Many studies aimed at investigating bone repair have been conducted through animal models in recent years. However, limitations do exist in these models due to varying regeneration potential among different animal species. Even using the same animal, big differences exist in the size of critical size defects (CSD) involving the same region. This study aimed to investigate the standardization of radial bone defect models in rabbits and further establish more reliable CSD data. A total of 40 6-month-old New Zealand white rabbits of clean grade totaling 80 radial bones were prepared for bone defect models, according to the principle of randomization. Five different sizes (1.0, 1.2, 1.4, 1.7 and 2.0 cm) of complete periosteal defects were introduced under anesthesia. At 12 weeks postoperatively, with the gradual increase in defect size, the grades of bone growth were significantly decreased in all 5 groups. X-ray, CT scans and H&E staining of the 1.4, 1.7, and 2.0-cm groups showed lower grades of bone growth than that of the 1.0 and 1.2-cm groups respectively (P < 0.05). Using rabbit radial defect model involving 6-month-old healthy New Zealand white rabbits, this study indicates that in order to be critical sized, defects must be greater than 1.4 cm. PMID:26731011

  7. Crack-growth analysis

    NASA Technical Reports Server (NTRS)

    Bianca, C.; Creager, M.

    1976-01-01

    Flexible, adaptable, integrative routine, computer program incorporates Collipriest-Ehret and Paris-Forman equations. Calculates growth from initial defect size and terminates calculation when crack is sufficiently large for critical condition. Wheeler, Willenborg, and Grumman Closure models are available.

  8. Evaluating printability of buried native extreme ultraviolet mask phase defects through a modeling and simulation approach

    NASA Astrophysics Data System (ADS)

    Upadhyaya, Mihir; Jindal, Vibhu; Basavalingappa, Adarsh; Herbol, Henry; Harris-Jones, Jenah; Jang, Il-Yong; Goldberg, Kenneth A.; Mochi, Iacopo; Marokkey, Sajan; Demmerle, Wolfgang; Pistor, Thomas V.; Denbeaux, Gregory

    2015-04-01

    Since completely defect-free masks will be hard to achieve, it is essential to have a good understanding of the printability of the native extreme ultraviolet (EUV) mask defects. In this work, we performed a systematic study of native mask defects to understand the defect printability they cause. The multilayer growth over native substrate mask blank defects was correlated to the multilayer growth over regular-shaped defects having similar profiles in terms of their width and height. To model the multilayer growth over the defects, a multilayer growth model based on a level-set technique was used that took into account the tool deposition conditions of the Veeco Nexus ion beam deposition tool. Further, the printability of the characterized native defects was studied at the SEMATECH-Berkeley Actinic Inspection Tool (AIT), an EUV mask-imaging microscope at Lawrence Berkeley National Laboratory. Printability of the modeled regular-shaped defects, which were propagated up the multilayer stack using level-set growth model, was studied using defect printability simulations implementing the waveguide algorithm. Good comparison was observed between AIT and the simulation results, thus demonstrating that multilayer growth over a defect is primarily a function of a defect's width and height, irrespective of its shape.

  9. The Acute Effect of Aerobic Exercise on Measures of Stress.

    ERIC Educational Resources Information Center

    Fort, Inza L.; And Others

    The immediate response of stress to aerobic exercise was measured by utilizing the Palmar Sweat Index (PSI) and the State-Trait Anxiety Inventory (STAI). Forty subjects (20 male and 20 female) from the ages of 18-30 sustained a single bout of aerobic activity for 30 minutes at 60 percent of their maximum heart rate. Pre-treatment procedures…

  10. Psychological Benefits of Aerobic Running: Implications for Mental Health Counselors.

    ERIC Educational Resources Information Center

    Hinkle, J. Scott

    1988-01-01

    Discusses the effect of aerobic running on psychological functioning and its adjunctive use in mental health counseling. Concludes that mental health counselors can provide more comprehensive services if they expand the psychoeducational model to include physiological parameters such as aerobic running that are associated with optimum mental…

  11. The Psychology, Physiology, and Creativity of Middle School Aerobic Exercisers.

    ERIC Educational Resources Information Center

    Hinkle, J. Scott; And Others

    1993-01-01

    Investigated effects of aerobic running program on psychological and physical fitness and creative abilities of eight-grade school children. Students (n=85) were randomly assigned to aerobic running treatment groups or to control groups who participated in traditional, nonaerobic physical education. Found statistically significant increases for…

  12. Aerobic Fitness Thresholds Associated with Fifth Grade Academic Achievement

    ERIC Educational Resources Information Center

    Wittberg, Richard; Cottrell, Lesley A.; Davis, Catherine L.; Northrup, Karen L.

    2010-01-01

    Background: Whereas effects of physical fitness and physical activity on cognitive function have been documented, little is known about how they are related. Purpose: This study assessed student aerobic fitness measured by FITNESSGRAM Mile times and/or Pacer circuits and whether the nature of the association between aerobic fitness and…

  13. Factors associated with low levels of aerobic fitness among adolescents

    PubMed Central

    Gonçalves, Eliane Cristina de Andrade; Silva, Diego Augusto Santos

    2016-01-01

    Abstract Objective: To evaluate the prevalence of low aerobic fitness levels and to analyze the association with sociodemographic factors, lifestyle and excess body fatness among adolescents of southern Brazil. Methods: The study included 879 adolescents aged 14-19 years the city of São José/SC, Brazil. The aerobic fitness was assessed by Canadian modified test of aerobic fitness. Sociodemographic variables (skin color, age, sex, study turn, economic level), sexual maturation and lifestyle (eating habits, screen time, physical activity, consumption of alcohol and tobacco) were assessed by a self-administered questionnaire. Excess body fatness was evaluated by sum of skinfolds triceps and subscapular. We used logistic regression to estimate odds ratios and 95% confidence intervals. Results: Prevalence of low aerobic fitness level was 87.5%. The girls who spent two hours or more in front screen, consumed less than one glass of milk by day, did not smoke and had an excess of body fatness had a higher chance of having lower levels of aerobic fitness. White boys with low physical activity had had a higher chance of having lower levels of aerobic fitness. Conclusions: Eight out of ten adolescents were with low fitness levels aerobic. Modifiable lifestyle factors were associated with low levels of aerobic fitness. Interventions that emphasize behavior change are needed. PMID:26743851

  14. Aerobic Digestion. Student Manual. Biological Treatment Process Control.

    ERIC Educational Resources Information Center

    Klopping, Paul H.

    This manual contains the textual material for a single-lesson unit on aerobic sludge digestion. Topic areas addressed include: (1) theory of aerobic digestion; (2) system components; (3) performance factors; (4) indicators of stable operation; and (5) operational problems and their solutions. A list of objectives, glossary of key terms, and…

  15. EFFECTS OF CORN SILAGE INOCULANTS ON AEROBIC STABILITY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aerobic stability of corn silage can be a major problem for farmers particularly in warm weather. Silage inoculants, while the most common type of silage additive, have not been consistently effective at improving aerobic stability. This study investigated new and proposed inoculant products over ...

  16. Aerobic Activity--Do Physical Education Programs Provide Enough?

    ERIC Educational Resources Information Center

    McGing, Eileen

    1989-01-01

    High school physical education curricula should concentrate less on sport skill development and competition, and more on health-related fitness and aerobic activity. Results are reported from a study of the type and amount of aerobic exercise provided in 29 high school physical education programs in a large metropolitan area. (IAH)

  17. Sexual dimorphism in primate aerobic capacity: a phylogenetic test.

    PubMed

    Lindenfors, Patrik; Revell, L J; Nunn, C L

    2010-06-01

    Male intrasexual competition should favour increased male physical prowess. This should in turn result in greater aerobic capacity in males than in females (i.e. sexual dimorphism) and a correlation between sexual dimorphism in aerobic capacity and the strength of sexual selection among species. However, physiological scaling laws predict that aerobic capacity should be lower per unit body mass in larger than in smaller animals, potentially reducing or reversing the sex difference and its association with measures of sexual selection. We used measures of haematocrit and red blood cell (RBC) counts from 45 species of primates to test four predictions related to sexual selection and body mass: (i) on average, males should have higher aerobic capacity than females, (ii) aerobic capacity should be higher in adult than juvenile males, (iii) aerobic capacity should increase with increasing sexual selection, but also that (iv) measures of aerobic capacity should co-vary negatively with body mass. For the first two predictions, we used a phylogenetic paired t-test developed for this study. We found support for predictions (i) and (ii). For prediction (iii), however, we found a negative correlation between the degree of sexual selection and aerobic capacity, which was opposite to our prediction. Prediction (iv) was generally supported. We also investigated whether substrate use, basal metabolic rate and agility influenced physiological measures of oxygen transport, but we found only weak evidence for a correlation between RBC count and agility. PMID:20406346

  18. 40 CFR 796.3100 - Aerobic aquatic biodegradation.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 32 2014-07-01 2014-07-01 false Aerobic aquatic biodegradation. 796.3100 Section 796.3100 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT (CONTINUED) CHEMICAL FATE TESTING GUIDELINES Transformation Processes § 796.3100 Aerobic aquatic biodegradation. (a)...

  19. 40 CFR 796.3100 - Aerobic aquatic biodegradation.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 33 2012-07-01 2012-07-01 false Aerobic aquatic biodegradation. 796.3100 Section 796.3100 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT (CONTINUED) CHEMICAL FATE TESTING GUIDELINES Transformation Processes § 796.3100 Aerobic aquatic biodegradation. (a)...

  20. 40 CFR 796.3100 - Aerobic aquatic biodegradation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 32 2011-07-01 2011-07-01 false Aerobic aquatic biodegradation. 796.3100 Section 796.3100 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT (CONTINUED) CHEMICAL FATE TESTING GUIDELINES Transformation Processes § 796.3100 Aerobic aquatic biodegradation. (a)...

  1. Micrograph Defect Indentifier

    2012-10-11

    Micrograph image defect identifier is a computer code written in MATLAB to automatically detect defects on scanned image of thin film membrane samples employing three methods: global threshold, line detection and k-means segmentation. The results are segmented binary images of thin film with defects identified. Defect area fractions are also calculated. The users may use default functional variables calculated by program, or input preferred value from user’s experience. This will empower the user to processingmore » the image with more flexibility. MDI was designed to identify defects of thin films fabricated. It is also used in phase identification, porosity study on SEM, OM, TEM images. Different methods were applied in this software package: global threshold, line detection and k-means segmentation.« less

  2. Micrograph Defect Indentifier

    SciTech Connect

    None, None

    2012-10-11

    Micrograph image defect identifier is a computer code written in MATLAB to automatically detect defects on scanned image of thin film membrane samples employing three methods: global threshold, line detection and k-means segmentation. The results are segmented binary images of thin film with defects identified. Defect area fractions are also calculated. The users may use default functional variables calculated by program, or input preferred value from user’s experience. This will empower the user to processing the image with more flexibility. MDI was designed to identify defects of thin films fabricated. It is also used in phase identification, porosity study on SEM, OM, TEM images. Different methods were applied in this software package: global threshold, line detection and k-means segmentation.

  3. Heart rate during aerobics classes in women with different previous experience of aerobics.

    PubMed

    Laukkanen, R M; Kalaja, M K; Kalaja, S P; Holmala, E B; Paavolainen, L M; Tummavuori, M; Virtanen, P; Rusko, H K

    2001-01-01

    This study measured heart rate during floor and step aerobic classes at three intensity levels. A group of 20 female occasional exercisers [mean age 33 (SD 8) years, mean body mass index 21 (SD 2) kg.m-2 volunteered to participate in six aerobic classes (three floor classes, three step classes) and in a laboratory test as members of one of two groups according to their prestudy regular participation in aerobics classes. Subjects in group A had participated four or more times a week and those of group B less than twice a week. The characteristics of the groups were as follows: group A, n = 10, mean maximal oxygen uptake (VO2max) 38.7 (SD 3.6) ml.kg-1.min-1, mean maximal heart rate (HRmax) 183 (SD 8) beats.min-1; group B, n = 10, VO2max 36.1 (SD 3.6) ml.kg-1.min-1, HRmax 178 (SD 7) beats.min-1. Each class consisted of a warm-up, a 20 min period of structured aerobic exercise (cardiophase) and a cool-down. The cardiophase was planned and guided as light, (rate of perceived exertion, RPE 11-12), moderate (RPE 13-14) or heavy (RPE 15-17) by an experienced instructor. The mean heart rates during the light classes were 72 (step) and 74 (floor) %HRmax in group A and 75 (step) and 79 (floor) %HRmax in group B; during the moderate classes, 84 (step) and 80 (floor) %HRmax in group A and 82 (step) and 83 (floor) %HRmax in group B, and during the heavy classes 89 (step and floor) %HRmax in group A and 88 (step) and 92 (floor) %HRmax in group B. Differences in heart rate and %HRmax were not statistically significant between the groups. However, differences in heart rate and %HRmax between the intensities (light vs moderate, moderate vs heavy and light vs heavy) were significant within both groups (all, P < 0.01). Based on the results, we conclude that intensity management during the aerobics classes was generally successful regardless of the participants' prior participation in aerobics. However, some individuals who were older and/or had less prior participation tended to

  4. Benzoate-induced stress enhances xylitol yield in aerobic fed-batch culture of Candida mogii TISTR 5892.

    PubMed

    Wannawilai, Siwaporn; Sirisansaneeyakul, Sarote; Chisti, Yusuf

    2015-01-20

    Production of the natural sweetener xylitol from xylose via the yeast Candida mogii TISTR 5892 was compared with and without the growth inhibitor sodium benzoate in the culture medium. Sodium benzoate proved to be an uncompetitive inhibitor in relatively poorly oxygenated shake flask aerobic cultures. In a better controlled aerobic environment of a bioreactor, the role of sodium benzoate could equally well be described as competitive, uncompetitive or noncompetitive inhibitor of growth. In intermittent fed-batch fermentations under highly aerobic conditions, the presence of sodium benzoate at 0.15gL(-1) clearly enhanced the xylitol titer relative to the control culture without the sodium benzoate. The final xylitol concentration and the average xylitol yield on xylose were nearly 50gL(-1) and 0.57gg(-1), respectively, in the presence of sodium benzoate. Both these values were substantially higher than reported for the same fermentation under microaerobic conditions. Therefore, a fed-batch aerobic fermentation in the presence of sodium benzoate is promising for xylitol production using C. mogii. PMID:25499077

  5. Metabolism of 2-Methylpropene (Isobutylene) by the Aerobic Bacterium Mycobacterium sp. Strain ELW1

    PubMed Central

    Kottegoda, Samanthi; Waligora, Elizabeth

    2015-01-01

    An aerobic bacterium (Mycobacterium sp. strain ELW1) that utilizes 2-methylpropene (isobutylene) as a sole source of carbon and energy was isolated and characterized. Strain ELW1 grew on 2-methylpropene (growth rate = 0.05 h−1) with a yield of 0.38 mg (dry weight) mg 2-methylpropene−1. Strain ELW1 also grew more slowly on both cis- and trans-2-butene but did not grow on any other C2 to C5 straight-chain, branched, or chlorinated alkenes tested. Resting 2-methylpropene-grown cells consumed ethene, propene, and 1-butene without a lag phase. Epoxyethane accumulated as the only detected product of ethene oxidation. Both alkene consumption and epoxyethane production were fully inhibited in cells exposed to 1-octyne, suggesting that alkene oxidation is initiated by an alkyne-sensitive, epoxide-generating monooxygenase. Kinetic analyses indicated that 1,2-epoxy-2-methylpropane is rapidly consumed during 2-methylpropene degradation, while 2-methyl-2-propen-1-ol is not a significant metabolite of 2-methylpropene catabolism. Degradation of 1,2-epoxy-2-methylpropane by 2-methylpropene-grown cells led to the accumulation and further degradation of 2-methyl-1,2-propanediol and 2-hydroxyisobutyrate, two sequential metabolites previously identified in the aerobic microbial metabolism of methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA). Growth of strain ELW1 on 2-methylpropene, 1,2-epoxy-2-methylpropane, 2-methyl-1,2-propanediol, and 2-hydroxyisobutyrate was fully inhibited when cobalt ions were omitted from the growth medium, while growth on 3-hydroxybutyrate and other substrates was unaffected by the absence of added cobalt ions. Our results suggest that, like aerobic MTBE- and TBA-metabolizing bacteria, strain ELW1 utilizes a cobalt/cobalamin-dependent mutase to transform 2-hydroxyisobutyrate. Our results have been interpreted in terms of their impact on our understanding of the microbial metabolism of alkenes and ether oxygenates. PMID:25576605

  6. Aerobic glycolysis in the human brain is associated with development and neotenous gene expression.

    PubMed

    Goyal, Manu S; Hawrylycz, Michael; Miller, Jeremy A; Snyder, Abraham Z; Raichle, Marcus E

    2014-01-01

    Aerobic glycolysis (AG; i.e., nonoxidative metabolism of glucose despite the presence of abundant oxygen) accounts for 10%-12% of glucose used by the adult human brain. AG varies regionally in the resting state. Brain AG may support synaptic growth and remodeling; however, data supporting this hypothesis are sparse. Here, we report on investigations on the role of AG in the human brain. Meta-analysis of prior brain glucose and oxygen metabolism studies demonstrates that AG increases during childhood, precisely when synaptic growth rates are highest. In resting adult humans, AG correlates with the persistence of gene expression typical of infancy (transcriptional neoteny). In brain regions with the highest AG, we find increased gene expression related to synapse formation and growth. In contrast, regions high in oxidative glucose metabolism express genes related to mitochondria and synaptic transmission. Our results suggest that brain AG supports developmental processes, particularly those required for synapse formation and growth. PMID:24411938

  7. Suppressor of K+ transport growth defect 1 (SKD1) interacts with RING-type ubiquitin ligase and sucrose non-fermenting 1-related protein kinase (SnRK1) in the halophyte ice plant.

    PubMed

    Chiang, Chih-Pin; Li, Chang-Hua; Jou, Yingtzy; Chen, Yu-Chan; Lin, Ya-Chung; Yang, Fang-Yu; Huang, Nu-Chuan; Yen, Hungchen Emilie

    2013-05-01

    SKD1 (suppressor of K+ transport growth defect 1) is an AAA-type ATPase that functions as a molecular motor. It was previously shown that SKD1 accumulates in epidermal bladder cells of the halophyte Mesembryanthemum crystallinum. SKD1 knock-down Arabidopsis mutants showed an imbalanced Na+/K+ ratio under salt stress. Two enzymes involved in protein post-translational modifications that physically interacted with McSKD1 were identified. McCPN1 (copine 1), a RING-type ubiquitin ligase, has an N-terminal myristoylation site that links to the plasma membrane, a central copine domain that interacts with McSKD1, and a C-terminal RING domain that catalyses protein ubiquitination. In vitro ubiquitination assay demonstrated that McCPN1 was capable of mediating ubiquitination of McSKD1. McSnRK1 (sucrose non-fermenting 1-related protein kinase) is a Ser/Thr protein kinase that contains an N-terminal STKc catalytic domain to phosphorylate McSKD1, and C-terminal UBA and KA1 domains to interact with McSKD1. The transcript and protein levels of McSnRK1 increased as NaCl concentrations increased. The formation of an SKD1-SnRK1-CPN1 ternary complex was demonstrated by yeast three-hybrid and bimolecular fluorescence complementation. It was found that McSKD1 preferentially interacts with McSnRK1 in the cytosol, and salt induced the re-distribution of McSKD1 and McSnRK1 towards the plasma membrane via the microtubule cytoskeleton and subsequently interacted with RING-type E3 McCPN1. The potential effects of ubiquitination and phosphorylation on McSKD1, such as changes in the ATPase activity and cellular localization, and how they relate to the functions of SKD1 in the maintenance of Na+/K+ homeostasis under salt stress, are discussed. PMID:23580756

  8. Defect Chemistry of Nanocarbon

    NASA Astrophysics Data System (ADS)

    Wang, Yuhuang

    2015-03-01

    Defects can rule the properties of a crystal. This effect is particularly intriguing in atom-thick materials such as single-walled carbon nanotubes and graphene, where electrons, excitons, phonons, and spin may strongly couple at the defect sites due to reduced dimensionality. In this talk, we will discuss our recent progress in fundamental understanding and molecular control of sp3 defects in sp2 carbon lattices, and their applications. An sp3 defect (tetrahedral bonding, diamond-like) is created by covalently attaching a functional group to the sp2 carbon lattice (trigonal planar, honeycomb-like) of a carbon nanotube or graphene. The beauty of this type of defect is its well-defined structure and chemical tunability at the molecular level. Our experimental results have unraveled a series of intriguing and surprising roles of defects. Specific examples will be given to illustrate how defects may be used to drive reaction propagation on sp2 carbon lattices, brighten carbon nanotube photoluminescence, and create selective chemical sensors.

  9. Wavelength dependent mask defects

    NASA Astrophysics Data System (ADS)

    Badger, Karen; Butt, Shahid; Burnham, Jay; Faure, Tom; Hibbs, Michael; Rankin, Jed; Thibault, David; Watts, Andrew

    2005-05-01

    For years there has been a mismatch between the photomask inspection wavelength and the usage conditions. While the non-actinic inspection has been a source for concern, there has been essentially no evidence that a defect "escaped" the mask production process due to the inspection mismatch. This paper will describe the discovery of one such defect, as well as the diagnostic and inspection techniques used to identify the location, analyze the composition, and determine the source of the printed wafer defect. Conventional mask inspection techniques revealed no defects, however an actinic Aerial Image Metrology System (AIMS) revealed a 1.5 mm region on the mask with up to 59% transmission reduction at 193 nm. Further diagnostics demonstrated a strong wavelength dependence which accounted for the near invisibility of the defect at I line (365 nm) or even DUV (248 nm) wavelengths, which had 0% and 5% respective transmission reductions. Using some creative imaging techniques via AIMS tool and modeling, the defect was deduced to have a three dimensional Gaussian absorption character, with total width approximately 1.5 mm. Several non-destructive diagnostic techniques were developed to determine the composition and location of the defect within the substrate. These results will be described in addition to identifying methods for ensuring product quality in the absence of actinic inspection.

  10. Requirement for terminal cytochromes in generation of the aerobic signal for the arc regulatory system in Escherichia coli: study utilizing deletions and lac fusions of cyo and cyd.

    PubMed Central

    Iuchi, S; Chepuri, V; Fu, H A; Gennis, R B; Lin, E C

    1990-01-01

    Escherichia coli has two terminal oxidases for its respiratory chain: cytochrome o (low O2 affinity) and cytochrome d (high O2 affinity). Expression of the cyo operon, encoding cytochrome o, is decreased by anaerobic growth, whereas expression of the cyd operon, encoding cytochrome d, is increased by anaerobic growth. We show by the use of lac gene fusion that the expressions of cyo and cyd are under the control of the two-component arc system. In a cyo+ cyd+ background, expression of phi(cyo-lac) is higher when the organism is grown aerobically than when it is grown anaerobically. A mutation in either the sensor gene arcB or the pleiotropic regulator gene arcA almost abolishes the anaerobic repression. In the same background, expression of phi(cyd-lac) is higher under anaerobic growth conditions than under aerobic growth conditions. A mutation in arcA or arcB lowers both the aerobic and anaerobic expressions, suggesting that ArcA plays an activating role instead of the typical repressing role. Under aerobic growth conditions, double deletions of cyo and cyd lower phi(cyo-lac) expression but enhance phi(cyd-lac) expression. The double deletions also prevent elevated aerobic induction of the lct operon (encoding L-lactate dehydrogenase), another target operon of the arc system. In contrast, these deletions do not circumvent aerobic repression of the nar operon (encoding the anaerobic respiratory enzyme nitrate reductase) under the control of the pleiotropic fnr gene product. It thus appears that ArcB senses the presence of O2 by level of an electron transport component in reduced form or that of an nonautoxidizable compound linked to the process by a redox reaction, whereas Fnr senses O2 by a different mechanism. PMID:2170337

  11. Brain aerobic glycolysis and motor adaptation learning

    PubMed Central

    Shannon, Benjamin J.; Vaishnavi, Sanjeev Neil; Vlassenko, Andrei G.; Shimony, Joshua S.; Rutlin, Jerrel; Raichle, Marcus E.

    2016-01-01

    Ten percent to 15% of glucose used by the brain is metabolized nonoxidatively despite adequate tissue oxygenation, a process termed aerobic glycolysis (AG). Because of the known role of glycolysis in biosynthesis, we tested whether learning-induced synaptic plasticity would lead to regionally appropriate, learning-dependent changes in AG. Functional MRI (fMRI) before, during, and after performance of a visual–motor adaptation task demonstrated that left Brodmann area 44 (BA44) played a key role in adaptation, with learning-related changes to activity during the task and altered resting-state, functional connectivity after the task. PET scans before and after task performance indicated a sustained increase in AG in left BA 44 accompanied by decreased oxygen consumption. Intersubject variability in behavioral adaptation rate correlated strongly with changes in AG in this region, as well as functional connectivity, which is consistent with a role for AG in synaptic plasticity. PMID:27217563

  12. Surface Structure of Aerobically Oxidized Diamond Nanocrystals

    PubMed Central

    2015-01-01

    We investigate the aerobic oxidation of high-pressure, high-temperature nanodiamonds (5–50 nm dimensions) using a combination of carbon and oxygen K-edge X-ray absorption, wavelength-dependent X-ray photoelectron, and vibrational spectroscopies. Oxidation at 575 °C for 2 h eliminates graphitic carbon contamination (>98%) and produces nanocrystals with hydroxyl functionalized surfaces as well as a minor component (<5%) of carboxylic anhydrides. The low graphitic carbon content and the high crystallinity of HPHT are evident from Raman spectra acquired using visible wavelength excitation (λexcit = 633 nm) as well as carbon K-edge X-ray absorption spectra where the signature of a core–hole exciton is observed. Both spectroscopic features are similar to those of chemical vapor deposited (CVD) diamond but differ significantly from the spectra of detonation nanodiamond. The importance of these findings to the functionalization of nanodiamond surfaces for biological labeling applications is discussed. PMID:25436035

  13. Brain aerobic glycolysis and motor adaptation learning.

    PubMed

    Shannon, Benjamin J; Vaishnavi, Sanjeev Neil; Vlassenko, Andrei G; Shimony, Joshua S; Rutlin, Jerrel; Raichle, Marcus E

    2016-06-28

    Ten percent to 15% of glucose used by the brain is metabolized nonoxidatively despite adequate tissue oxygenation, a process termed aerobic glycolysis (AG). Because of the known role of glycolysis in biosynthesis, we tested whether learning-induced synaptic plasticity would lead to regionally appropriate, learning-dependent changes in AG. Functional MRI (fMRI) before, during, and after performance of a visual-motor adaptation task demonstrated that left Brodmann area 44 (BA44) played a key role in adaptation, with learning-related changes to activity during the task and altered resting-state, functional connectivity after the task. PET scans before and after task performance indicated a sustained increase in AG in left BA 44 accompanied by decreased oxygen consumption. Intersubject variability in behavioral adaptation rate correlated strongly with changes in AG in this region, as well as functional connectivity, which is consistent with a role for AG in synaptic plasticity. PMID:27217563

  14. Biology of Moderately Halophilic Aerobic Bacteria

    PubMed Central

    Ventosa, Antonio; Nieto, Joaquín J.; Oren, Aharon

    1998-01-01

    The moderately halophilic heterotrophic aerobic bacteria form a diverse group of microorganisms. The property of halophilism is widespread within the bacterial domain. Bacterial halophiles are abundant in environments such as salt lakes, saline soils, and salted food products. Most species keep their intracellular ionic concentrations at low levels while synthesizing or accumulating organic solutes to provide osmotic equilibrium of the cytoplasm with the surrounding medium. Complex mechanisms of adjustment of the intracellular environments and the properties of the cytoplasmic membrane enable rapid adaptation to changes in the salt concentration of the environment. Approaches to the study of genetic processes have recently been developed for several moderate halophiles, opening the way toward an understanding of haloadaptation at the molecular level. The new information obtained is also expected to contribute to the development of novel biotechnological uses for these organisms. PMID:9618450

  15. Defect solitons in photonic lattices.

    PubMed

    Yang, Jianke; Chen, Zhigang

    2006-02-01

    Nonlinear defect modes (defect solitons) and their stability in one-dimensional photonic lattices with focusing saturable nonlinearity are investigated. It is shown that defect solitons bifurcate out from every infinitesimal linear defect mode. Low-power defect solitons are linearly stable in lower bandgaps but unstable in higher bandgaps. At higher powers, defect solitons become unstable in attractive defects, but can remain stable in repulsive defects. Furthermore, for high-power solitons in attractive defects, we found a type of Vakhitov-Kolokolov (VK) instability which is different from the usual VK instability based on the sign of the slope in the power curve. Lastly, we demonstrate that in each bandgap, in addition to defect solitons which bifurcate from linear defect modes, there is also an infinite family of other defect solitons which can be stable in certain parameter regimes. PMID:16605473

  16. What Are Neural Tube Defects?

    MedlinePlus

    ... NICHD Research Information Clinical Trials Resources and Publications Neural Tube Defects (NTDs): Condition Information Skip sharing on ... media links Share this: Page Content What are neural tube defects? Neural (pronounced NOOR-uhl ) tube defects ...

  17. Atrial Septal Defect (For Teens)

    MedlinePlus

    ... I Help a Friend Who Cuts? Atrial Septal Defect KidsHealth > For Teens > Atrial Septal Defect Print A ... Care of Yourself What Is an Atrial Septal Defect? Having a doctor listen to your heart is ...

  18. [Research of aerobic granule characteristics with different granule age].

    PubMed

    Zhou, Man; Yang, Chang-Zhu; Pu, Wen-Hong; Luo, Ying-Dong; Gong, Jian-Yu

    2012-03-01

    In the SBR reactor, we studied the different style, physicochemical characteristic, pollutants removal and microbial activity between the short age and long age aerobic granule, respectively. The short age aerobic granule was cultivated from activated floccules sludge and the other was gotten from aerobic granular sludge which was operated stably more than one year. The results indicated that the wet density, the specific gravity and integrated coefficient (IC) of the short age aerobic granule were 1.066 g x cm(-1), 1.013 g x cm(-3) and 98.7%, respectively. And that of long age were 1.026 g x cm(-3), 1.010 g x cm(-3) and 98.4%, respectively. All of them were higher than the long age aerobic granule. The mean diameters of them were 1.9 mm and 2.2 mm, respectively. The settling velocity of short age and long age aerobic granule were 0.005-0.032 m x s(-1) and 0.003-0.028 m x s(-1), respectively, and two kinds of aerobic granule settling velocity increased with the diameter increased. SVI of the former was lower. The COD removal rates of two aerobic granules were above 90%, and the NH4(+) -N removal rates of them were about 85%. The results of the COD effluent concentration, NH4(+) -N effluent concentration and the pollutants concentration in a typical cycle indicated that the short age aerobic granule had better pollutants removal efficiency. The TP removal rates of them were between 40% -90% and 32% -85%, respectively. The TN removal rates of them were about 80%. The SOUR(H) SOUR(NH4) and SOUR(NO2) of the short age aerobic granule were 26.4, 14.8 and 11.2 mg x (h x g)(-1), respectively. And that of long age were 25.2, 14.4 and 8.4 mg x (h x g)(-1), respectively. In summary, the aerobic granule had significantly different physical and chemical characteristics because of different granule age, and the short age aerobic granule exhibited better pollutants removal ability, higher microbial activity and more stability than the long age aerobic granule. PMID:22624385

  19. Effects of Kettlebell Training on Aerobic Capacity.

    PubMed

    Falatic, J Asher; Plato, Peggy A; Holder, Christopher; Finch, Daryl; Han, Kyungmo; Cisar, Craig J

    2015-07-01

    This study examined the effects of a kettlebell training program on aerobic capacity. Seventeen female National Collegiate Athletic Association Division I collegiate soccer players (age: 19.7 ± 1.0 years, height: 166.1 ± 6.4 cm, weight: 64.2 ± 8.2 kg) completed a graded exercise test to determine maximal oxygen consumption (V̇O2max). Participants were assigned to a kettlebell intervention group (KB) (n = 9) or a circuit weight-training (CWT) control group (n = 8). Participants in the KB group completed a kettlebell snatch test to determine individual snatch repetitions. Both groups trained 3 days a week for 4 weeks in addition to their off-season strength and conditioning program. The KB group performed the 15:15 MVO2 protocol (20 minutes of kettlebell snatching with 15 seconds of work and rest intervals). The CWT group performed multiple free-weight and dynamic body-weight exercises as part of a continuous circuit program for 20 minutes. The 15:15 MVO2 protocol significantly increased V̇O2max in the KB group. The average increase was 2.3 ml·kg⁻¹·min⁻¹, or approximately a 6% gain. There was no significant change in V̇O2max in the CWT control group. Thus, the 4-week 15:15 MVO2 kettlebell protocol, using high-intensity kettlebell snatches, significantly improved aerobic capacity in female intercollegiate soccer players and could be used as an alternative mode to maintain or improve cardiovascular conditioning. PMID:26102260

  20. Functional characterization of Yersinia pestis aerobic glycerol metabolism.

    PubMed

    Willias, Stephan P; Chauhan, Sadhana; Motin, Vladimir L

    2014-11-01

    Yersinia pestis biovar Orientalis isolates have lost the capacity to ferment glycerol. Herein we provide experimental validation that a 93 bp in-frame deletion within the glpD gene encoding the glycerol-3-phosphate dehydrogenase present in all biovar Orientalis strains is sufficient to disrupt aerobic glycerol fermentation. Furthermore, the inability to ferment glycerol is often insured by a variety of additional mutations within the glpFKX operon which prevents glycerol internalization and conversion to glycerol-3-phosphate. The physiological impact of functional glpFKX in the presence of dysfunctional glpD was assessed. Results demonstrate no change in growth kinetics at 26 °C and 37 °C. Mutants deficient in glpD displayed decreased intracellular accumulation of glycerol-3-phosphate, a characterized inhibitor of cAMP receptor protein (CRP) activation. Since CRP is rigorously involved in global regulation Y. pestis virulence, we tested a possible influence of a single glpD mutation on virulence. Nonetheless, subcutaneous and intranasal murine challenge was not impacted by glycerol metabolism. As quantified by crystal violet assay, biofilm formation of the glpD-deficient KIM6+ mutant was mildly repressed; whereas, chromosomal restoration of glpD in CO92 resulted in a significant increase in biofilm formation. PMID:25220241

  1. Reduction of aerobic acetate production by Escherichia coli.

    PubMed Central

    Farmer, W R; Liao, J C

    1997-01-01

    Acetate excretion by Escherichia coli during aerobic growth on glucose is a major obstacle to enhanced recombinant protein production. We report here that the fraction of carbon flux through the anaplerotic pathways is one of the factors influencing acetate excretion. Flux analysis of E. coli central metabolic pathways predicts that increasing the fraction of carbon flux through the phosphoenolpyruvate carboxylase (PPC) pathway and the glyoxylate bypass reduces acetate production. We tested this prediction by overexpressing PPC and deregulating the glyoxylate bypass by using a fadR strain. Results show that the acetate yield by the fadR strain with PPC overexpression is decreased more than fourfold compared to the control, while the biomass yield is relatively unaffected. Apparently, the fraction of carbon flux through the anaplerotic pathways is one of the factors that influence acetate excretion. These results confirm the prediction of our flux analysis and further suggest that E. coli is not fully optimized for efficient utilization of glucose. PMID:9251207

  2. Aerobic cyanide degradation by bacterial isolates from cassava factory wastewater

    PubMed Central

    Kandasamy, Sujatha; Dananjeyan, Balachandar; Krishnamurthy, Kumar; Benckiser, Gero

    2015-01-01

    Ten bacterial strains that utilize cyanide (CN) as a nitrogen source were isolated from cassava factory wastewater after enrichment in a liquid media containing sodium cyanide (1 mM) and glucose (0.2% w/v). The strains could tolerate and grow in cyanide concentrations of up to 5 mM. Increased cyanide levels in the media caused an extension of lag phase in the bacterial growth indicating that they need some period of acclimatisation. The rate of cyanide removal by the strains depends on the initial cyanide and glucose concentrations. When initial cyanide and glucose concentrations were increased up to 5 mM, cyanide removal rate increased up to 63 and 61 per cent by Bacillus pumilus and Pseudomonas putida. Metabolic products such as ammonia and formate were detected in culture supernatants, suggesting a direct hydrolytic pathway without an intermediate formamide. The study clearly demonstrates the potential of aerobic treatment with cyanide degrading bacteria for cyanide removal in cassava factory wastewaters. PMID:26413045

  3. Effect of Aerobic Priming on the Response of Echinochloa crus-pavonis to Anaerobic Stress (Protein Synthesis and Phosphorylation).

    PubMed Central

    Zhang, F.; Lin, J. J.; Fox, T. C.; Mujer, C. V.; Rumpho, M. E.; Kennedy, R. A.

    1994-01-01

    Echinochloa species differ in their ability to germinate and grow in the absence of oxygen. Seeds of Echinochloa crus-pavonis (H.B.K.) Schult do not germinate under anoxia but remain viable for extended periods (at least 30 d) when incubated in an anaerobic environment. E. crus-pavonis can be induced to germinate and grow in an anaerobic environment if the seeds are first subjected to a short (1-18 h) exposure to aerobic conditions (aerobic priming). Changes in polypeptide patterns (constitutive and de novo synthesized) and protein phosphorylation induced by aerobic priming were investigated. In the absence of aerobic priming protein degradation was not evident under anaerobic conditions, although synthesis of a 20-kD polypeptide was induced. During aerobic priming, however, synthesis of 37- and 55-kD polypeptides was induced and persisted upon return of the seeds to anoxia. Furthermore, phosphorylation of two 18-kD polypeptides was observed only in those seeds that were labeled with 32PO4 during the aerobic priming period. Subsequent chasing in an anaerobic environment resulted in a decrease in phosphorylation of these polypeptides. Likewise, phosphorylation of the 18-kD polypeptides was not observed if the seeds were labeled in an anaerobic atmosphere. These results suggest that the regulated induction of the 20-, 37-, and 55- kD polypeptides may be important for anaerobic germination and growth of E. crus-pavonis and that the specific phosphorylation of the 18-kD polypeptides may be a factor in regulating this induction. PMID:12232272

  4. Role of ammonia-oxidizing bacteria in micropollutant removal from wastewater with aerobic granular sludge.

    PubMed

    Margot, Jonas; Lochmatter, Samuel; Barry, D A; Holliger, Christof

    2016-01-01

    Nitrifying wastewater treatment plants (WWTPs) are more efficient than non-nitrifying WWTPs to remove several micropollutants such as pharmaceuticals and pesticides. This may be related to the activity of nitrifying organisms, such as ammonia-oxidizing bacteria (AOBs), which could possibly co-metabolically oxidize micropollutants with their ammonia monooxygenase (AMO). The role of AOBs in micropollutant removal was investigated with aerobic granular sludge (AGS), a promising technology for municipal WWTPs. Two identical laboratory-scale AGS sequencing batch reactors (AGS-SBRs) were operated with or without nitrification (inhibition of AMOs) to assess their potential for micropollutant removal. Of the 36 micropollutants studied at 1 μg l(-1) in synthetic wastewater, nine were over 80% removed, but 17 were eliminated by less than 20%. Five substances (bisphenol A, naproxen, irgarol, terbutryn and iohexol) were removed better in the reactor with nitrification, probably due to co-oxidation catalysed by AMOs. However, for the removal of all other micropollutants, AOBs did not seem to play a significant role. Many compounds were better removed in aerobic condition, suggesting that aerobic heterotrophic organisms were involved in the degradation. As the AGS-SBRs did not favour the growth of such organisms, their potential for micropollutant removal appeared to be lower than that of conventional nitrifying WWTPs. PMID:26877039

  5. Kinetics and thermodynamics of biodegradation of hydrolyzed polyacrylamide under anaerobic and aerobic conditions.

    PubMed

    Zhao, Lanmei; Bao, Mutai; Yan, Miao; Lu, Jinren

    2016-09-01

    Kinetics and thermodynamics of hydrolyzed polyacrylamide (HPAM) biodegradation in anaerobic and aerobic activated sludge biochemical treatment systems were explored to determine the maximum rate and feasibility of HPAM biodegradation. The optimal nutrient proportions for HPAM biodegradation were determined to be 0.08g·L(-1) C6H12O6, 1.00g·L(-1) NH4Cl, 0.36g·L(-1) NaH2PO4 and 3.00g·L(-1) K2HPO4 using response surface methodology (RSM). Based on the kinetics, the maximum HPAM biodegradation rates were 16.43385mg·L(-1)·d(-1) and 2.463mg·L(-1)·d(-1) in aerobic and anaerobic conditions, respectively. The activation energy (Ea) of the aerobic biodegradation was 48.9897kJ·mol(-1). Entropy changes (ΔS) of biochemical treatment system decreased from 216.21J·K(-1) to 2.39J·K(-1). Thermodynamic windows of opportunity for HPAM biodegradation were drawn. And it demonstrated HPAM was biodegraded into acetic acid and CO2 under laboratory conditions. Growth-process equations for functional bacteria anaerobically grown on polyacrylic acid were constructed and it confirmed electron equivalence between substrate and product. PMID:27235971

  6. Mathematical modeling of the effects of aerobic and anaerobic chelate bioegradation on actinide speciation.

    SciTech Connect

    Banaszak, J.E.; VanBriesen, J.; Rittmann, B.E.; Reed, D.T.

    1998-03-19

    Biodegradation of natural and anthropogenic chelating agents directly and indirectly affects the speciation, and, hence, the mobility of actinides in subsurface environments. We combined mathematical modeling with laboratory experimentation to investigate the effects of aerobic and anaerobic chelate biodegradation on actinide [Np(IV/V), Pu(IV)] speciation. Under aerobic conditions, nitrilotriacetic acid (NTA) biodegradation rates were strongly influenced by the actinide concentration. Actinide-chelate complexation reduced the relative abundance of available growth substrate in solution and actinide species present or released during chelate degradation were toxic to the organisms. Aerobic bio-utilization of the chelates as electron-donor substrates directly affected actinide speciation by releasing the radionuclides from complexed form into solution, where their fate was controlled by inorganic ligands in the system. Actinide speciation was also indirectly affected by pH changes caused by organic biodegradation. The two concurrent processes of organic biodegradation and actinide aqueous chemistry were accurately linked and described using CCBATCH, a computer model developed at Northwestern University to investigate the dynamics of coupled biological and chemical reactions in mixed waste subsurface environments. CCBATCH was then used to simulate the fate of Np during anaerobic citrate biodegradation. The modeling studies suggested that, under some conditions, chelate degradation can increase Np(IV) solubility due to carbonate complexation in closed aqueous systems.

  7. Intrinsic defect formation in peptide self-assembly

    NASA Astrophysics Data System (ADS)

    Deng, Li; Zhao, Yurong; Xu, Hai; Wang, Yanting

    2015-07-01

    In contrast to extensively studied defects in traditional materials, we report here a systematic investigation of the formation mechanism of intrinsic defects in self-assembled peptide nanostructures. The Monte Carlo simulations with our simplified dynamic hierarchical model revealed that the symmetry breaking of layer bending mode at the two ends during morphological transformation is responsible for intrinsic defect formation, whose microscopic origin is the mismatch between layer stacking along the side-chain direction and layer growth along the hydrogen bond direction. Moreover, defect formation does not affect the chirality of the self-assembled structure, which is determined by the initial steps of the peptide self-assembly process.

  8. Echocardiography for the Assessment of Congenital Heart Defects in Calves.

    PubMed

    Mitchell, Katharyn Jean; Schwarzwald, Colin Claudio

    2016-03-01

    Congenital heart disease should be considered when evaluating calves with chronic respiratory signs, failure to thrive, poor growth, or if a murmur is heard on physical examination. Echocardiography is currently the gold standard for diagnosing congenital heart defects. A wide variety of defects, either alone or in combination with a ventricular septal defect, are possible. A standardized approach using sequential segmental analysis is required to fully appreciate the nature and severity of more complex malformations. The prognosis for survival varies from guarded to poor and depends on the hemodynamic relevance of the defects and the degree of cardiac compensation. PMID:26922111

  9. Automated Defect Classification (ADC)

    1998-01-01

    The ADC Software System is designed to provide semiconductor defect feature analysis and defect classification capabilities. Defect classification is an important software method used by semiconductor wafer manufacturers to automate the analysis of defect data collected by a wide range of microscopy techniques in semiconductor wafer manufacturing today. These microscopies (e.g., optical bright and dark field, scanning electron microscopy, atomic force microscopy, etc.) generate images of anomalies that are induced or otherwise appear on wafermore » surfaces as a result of errant manufacturing processes or simple atmospheric contamination (e.g., airborne particles). This software provides methods for analyzing these images, extracting statistical features from the anomalous regions, and applying supervised classifiers to label the anomalies into user-defined categories.« less

  10. Birth Defects (For Parents)

    MedlinePlus

    ... Ones & When? Smart School Lunches Emmy-Nominated Video "Cerebral Palsy: Shannon's Story" 5 Things to Know About Zika & ... defects. Clefting can be surgically repaired after birth. Cerebral palsy usually isn't found until weeks to months ...

  11. Birth defects monitoring

    SciTech Connect

    Klingberg, M.A.; Papier, C.M.; Hart, J.

    1983-01-01

    Population monitoring of birth defects provides a means for detecting relative changes in their frequency. Many varied systems have been developed throughout the world since the thalidomide tragedy of the early 1960s. Although it is difficult to pinpoint specific teratogenic agents based on rises in rates of a particular defect or a constellation of defects, monitoring systems can provide clues for hypothesis testing in epidemiological investigations. International coordination of efforts in this area resulted in the founding of the International Clearinghouse for Birth Defects Monitoring Systems (ICBDMS) in 1974. In this paper we will describe the functions and basic requirements of monitoring systems in general, and look at the development and activities of the ICBDMS. A review of known and suspected environmental teratogenic agents (eg, chemical, habitual, biological, physical, and nutritional) is also presented.

  12. Congenital Heart Defects

    MedlinePlus

    ... Treatment can include medicines, catheter procedures, surgery, and heart transplants. The treatment depends on the type of the defect, how severe it is, and a child's age, size, and general health. NIH: National Heart, Lung, and Blood Institute

  13. Sequential anaerobic/aerobic biotreatment of bark leachate.

    PubMed

    Frigon, J C; Cimpoia, R; Guiot, S R

    2003-01-01

    Bark leachate is generated from sawmill operations such as log storage sites and contains polymeric tannins, carbohydrates, organic acids, phenolic and resin compounds. The present study was aimed at assessing the performance of a sequential anaerobic and aerobic treatment, for both chemical oxygen demand (COD) and phenol removal, under various combinations of operational conditions, in the continuous mode. After anaerobic treatment in a five litres upflow anaerobic sludge bed (UASB) reactor, the leachate was directed into two parallel aerobic reactors, either an activated sludge unit or a fixed film submerged filter (packed with polyethylene Flexirings), both of a volume of one litre and oxygenated by air diffusion. For a leachate of 22 gCOD/l, an overall COD removal of 96-98% was achieved at an hydraulic residence time (HRT) of 4 days for the anaerobic reactor and one day for either aerobic systems. The phenol concentration generally increased after anaerobic treatment but was below the detection limit (50 ppb) after aerobic polishing. Radiorespirometric microcosms with 14C-labelled phenol confirmed that phenol was mineralized in the aerobic reactors. The performances of both aerobic systems were similar for COD and phenol removal. Thus, a sequential anaerobic/aerobic treatment was able to effectively address the contamination of a bark leachate discharge, including phenols. PMID:14640219

  14. Cardioprotective Properties of Aerobic and Resistance Training Against Myocardial Infarction.

    PubMed

    Barboza, C A; Souza, G I H; Oliveira, J C M F; Silva, L M; Mostarda, C T; Dourado, P M M; Oyama, L M; Lira, F S; Irigoyen, M C; Rodrigues, B

    2016-06-01

    We evaluated the effects of aerobic and resistance exercise training on ventricular morphometry and function, physical capacity, autonomic function, as well as on ventricular inflammatory status in trained rats prior to myocardial infarction. Male Wistar rats were divided into the following groups: sedentary+Sham, sedentary+myocardial infarction, aerobic trained+myocardial infarction, and resistance trained+myocardial infarction. Sham and myocardial infarction were performed after training periods. In the days following the surgeries, evaluations were performed. Aerobic training prevents aerobic (to a greater extent) and resistance capacity impairments, ventricular dysfunction, baroreflex sensitivity and autonomic disorders (vagal tonus decrease and sympathetic tonus increase) triggered by myocardial infarction. Resistance training was able to prevent negative changes to aerobic and resistance capacity (to a greater extent) but not to ventricular dysfunction, and it prevented cardiovascular sympathetic increments. Additionally, both types of training reduced left ventricle inflammatory cytokine concentration. Our results suggest that aerobic and, for the first time, dynamic resistance training were able to reduce sympathetic tonus to the heart and vessels, as well as preventing the increase in pro-inflammatory cytokine concentrations in the left ventricle of trained groups. These data emphasizes the positive effects of aerobic and dynamic resistance training on the prevention of the negative changes triggered by myocardial infarction. PMID:26928914

  15. Coordinated Metabolic Transitions During Drosophila Embryogenesis and the Onset of Aerobic Glycolysis

    PubMed Central

    Tennessen, Jason M.; Bertagnolli, Nicolas M.; Evans, Janelle; Sieber, Matt H.; Cox, James; Thummel, Carl S.

    2014-01-01

    Rapidly proliferating cells such as cancer cells and embryonic stem cells rely on a specialized metabolic program known as aerobic glycolysis, which supports biomass production from carbohydrates. The fruit fly Drosophila melanogaster also utilizes aerobic glycolysis to support the rapid growth that occurs during larval development. Here we use singular value decomposition analysis of modENCODE RNA-seq data combined with GC-MS-based metabolomic analysis to analyze the changes in gene expression and metabolism that occur during Drosophila embryogenesis, spanning the onset of aerobic glycolysis. Unexpectedly, we find that the most common pattern of co-expressed genes in embryos includes the global switch to glycolytic gene expression that occurs midway through embryogenesis. In contrast to the canonical aerobic glycolytic pathway, however, which is accompanied by reduced mitochondrial oxidative metabolism, the expression of genes involved in the tricarboxylic cycle (TCA cycle) and the electron transport chain are also upregulated at this time. Mitochondrial activity, however, appears to be attenuated, as embryos exhibit a block in the TCA cycle that results in elevated levels of citrate, isocitrate, and α-ketoglutarate. We also find that genes involved in lipid breakdown and β-oxidation are upregulated prior to the transcriptional initiation of glycolysis, but are downregulated before the onset of larval development, revealing coordinated use of lipids and carbohydrates during development. These observations demonstrate the efficient use of nutrient stores to support embryonic development, define sequential metabolic transitions during this stage, and demonstrate striking similarities between the metabolic state of late-stage fly embryos and tumor cells. PMID:24622332

  16. Upper limb aerobic training improves aerobic fitness and all-out performance of America's Cup grinders.

    PubMed

    Adami, Paolo Emilio; Delussu, Anna Sofia; Rodio, Angelo; Squeo, Maria Rosaria; Corsi, Loretta; Quattrini, Filippo Maria; Fattorini, Luigi; Bernardi, Marco

    2015-01-01

    This research on "America's Cup" grinders investigated the effects of a specific eight-week long-arm cranking ergometer (ACE) training on upper body (UB) aerobic fitness (ventilatory threshold - Tvent, respiratory compensation point- RCP, -oxygen uptake peak - VO₂peak) and high intensity working capacity. The training consisted of sessions carried out for 20-30 mins, three times per week, at an intensity between the UB-Tvent and UB-RCP, and replaced part of a typical lower limb aerobic training whilst maintaining the usual weekly schedule of callisthenics, resistance training and sailing. Seven sailors, including four grinders and three mastmen (age 30 ± 5.5 years, height 1.9 ± 0.04 m, body mass 102 ± 3.6 kg), were evaluated through both an ACE cardiopulmonary maximal exercise test (CPET) and an ACE all-out up to exhaustion exercise test, before and after the ACE training. UB aerobic fitness improved significantly: UB-VO₂peak increased from 4.29 ± 0.442 to 4.52 ± 0.522 l·min(-1) (6.4 ± 3.66%), VO₂ at UB-Tvent from 2.42 ± 0.282 to 2.97 ± 0.328 l·min(-1) (22.8 ± 5.09%) and VO₂ at UB-RCP from 3.25 ± 0.402 to 3.75 ± 0.352 l·min(-1) (16.1 ± 10.83%). Peak power at the ACE CPET increased from 351 ± 27.5 to 387 ± 33.5 W (10.5 ± 6.93%). The all-out test total mechanical work increased from 28.9 ± 2.35 to 40.1 ± 3.76 kJ (72.1 ± 4.67%). In conclusion, a high intensity aerobic ACE training can be effective in improving grinding performance by increasing UB aerobic fitness and all-out working capacity. PMID:25357134

  17. Anaerobic digestion of dairy cattle manure autoheated by aerobic pretreatment

    SciTech Connect

    Achkari-Begdouri, A.

    1989-01-01

    A novel way to heat anaerobic digesters was investigated. Dairy cattle manure was autoheated by an aerobic pretreatment process and then fed to the anaerobic digester. Important physical properties of the dairy cattle manure were determined. These included bulk density, specific heat, thermal conductivity and the rheological properties; consistency coefficient, behavior index and apparent viscosity. These parameters were used to calculate the overall heat transfer coefficients, and to estimate the heat losses from the aerobic reactor to the outside environment. The total energy balance of the aerobic treatment system was then established. An optimization study of the main parameters influencing the autoheating process showed that the total solids, the air flow rate and the stirring speed for operation of the aerobic pretreatment should be approximately 7%, 70 L/H and 1,400 rpm respectively. Temperatures as high as 65C were reached in 40 hours of aerobic treatment. At the above recommended levels of total solids, the air flow rate and the stirring speed, there was little difference in the energy requirements for heating the influent by aeration and heating the influent by a conventional heating system. In addition to the temperature increase, the aerobic pretreatment assisted in balancing the anaerobic digestion process and increased the methanogenesis of the dairy cattle manure. Despite the 8% decomposition of organic matter that occurred during the aerobic pretreatment process, methane production of the digester started with the aerobically heated manure was significantly higher (at least 20% higher) than of the digester started with conventionally heated manure. The aerobic system successfully autoheated the dairy cattle manure with an energy cost equal to that of conventionally heated influent.

  18. Interaction of Cadmium With the Aerobic Bacterium Pseudomonas Mendocina

    NASA Astrophysics Data System (ADS)

    Schramm, P. J.; Haack, E. A.; Maurice, P. A.

    2006-05-01

    The fate of toxic metals in the environment can be heavily influenced by interaction with bacteria in the vadose zone. This research focuses on the interactions of cadmium with the strict aerobe Pseudomonas mendocina. P. mendocina is a gram-negative bacterium that has shown potential in the bioremediation of recalcitrant organic compounds. Cadmium is a common environmental contaminant of wide-spread ecological consequence. In batch experiments P. mendocina shows typical bacterial growth curves, with an initial lag phase followed by an exponential phase and a stationary to death phase; concomitant with growth was an increase in pH from initial values of 7 to final values at 96 hours of 8.8. Cd both delays the onset of the exponential phase and decreases the maximum population size, as quantified by optical density and microscopic cell counts (DAPI). The total amount of Cd removed from solution increases over time, as does the amount of Cd removed from solution normalized per bacterial cell. Images obtained with transmission electron microscopy (TEM) showed the production of a cadmium, phosphorus, and iron containing precipitate that was similar in form and composition to precipitates formed abiotically at elevated pH. However, by late stationary phase, the precipitate had been re-dissolved, perhaps by biotic processes in order to obtain Fe. Stressed conditions are suggested by TEM images showing the formation of pili, or nanowires, when 20ppm Cd was present and a marked decrease in exopolysaccharide and biofilm material in comparison to control cells (no cadmium added).

  19. Aerobic Exercise Program Reduces Anger Expression Among Overweight Children

    PubMed Central

    Tkacz, Joseph; Young-Hyman, Deborah; Boyle, Colleen A.; Davis, Catherine L.

    2009-01-01

    This study tested the effect of a structured aerobic exercise program on anger expression in healthy overweight children. Overweight, sedentary children were randomly assigned to an aerobic exercise program or a no-exercise control condition. All children completed the Pediatric Anger Expression Scale at baseline and posttest. Anger Out and Anger Expression scores were lower for the exercise condition at posttest. Fitness improvements contributed significantly to final models, and points earned for adherence correlated negatively with posttest Anger Out. An aerobic exercise program might be an effective strategy to reduce anger expression, including reduction of aggressive behavior, in overweight children. PMID:19168916

  20. Considerations in prescribing preflight aerobic exercise for astronauts

    NASA Technical Reports Server (NTRS)

    Frey, Mary Anne Bassett

    1987-01-01

    The physiological effects of prolonged exposure to weightlessness are discussed together with the effects of aerobic exercise on human characteristics affected by weightlessness. It is noted that, although early data on orthostatic intolerance after spaceflight led to a belief that a high level of aerobic fitness for astronauts was detrimental to orthostatic tolerance on return to earth, most of the data available today do not suport this contention. Aerobic fitness was found to be beneficial to cardiovascular function and to mental performance; therefore, it may be important in performing extravehicular activities during flight.

  1. Evaluation of Biodegradability of Waste Before and After Aerobic Treatment

    NASA Astrophysics Data System (ADS)

    Suchowska-Kisielewicz, Monika; Jędrczak, Andrzej; Sadecka, Zofia

    2014-12-01

    An important advantage of use of an aerobic biostabilization of waste prior to its disposal is that it intensifies the decomposition of the organic fraction of waste into the form which is easily assimilable for methanogenic microorganisms involved in anaerobic decomposition of waste in the landfill. In this article it is presented the influence of aerobic pre-treatment of waste as well as leachate recirculation on susceptibility to biodegradation of waste in anaerobic laboratory reactors. The research has shown that in the reactor with aerobically treated waste stabilized with recilculation conversion of the organic carbon into the methane is about 45% higher than in the reactor with untreated waste stabilized without recirculation.

  2. Comment on "Investigations of interstitial generations near growth interface depending on crystal pulling rates during CZ silicon growth by detaching from the melt" by T. Abe et al. [J. Cryst. Growth 434 (2016) 128-137] and on "Observations of secondary defects and vacancies in CZ silicon crystals detached from melt using four different types of characterization technique" by T. Abe et al. [J. Cryst. Growth 436 (2016) 23-33

    NASA Astrophysics Data System (ADS)

    Vanhellemont, Jan; Kamiyama, Eiji; Nakamura, Kozo; Sueoka, Koji

    2016-09-01

    In the papers mentioned above, Abe et al. published beautiful experimental data on intrinsic point defect related defect distributions in detached growing Czochralski Si crystals with and without additional thermal anneals [1,2]. The new fact compared to the results published before [3] is that the crystals are pulled with decreasing speed before detaching, resulting in crystals that vary along the axis from initially vacancy-rich to interstitial-rich for the slowest pulling speed before detaching.

  3. Dissolution of Fe(III)(hydr)oxides by an Aerobic Bacterium

    SciTech Connect

    Maurice, P.

    2004-12-13

    This project investigated the effects of an aerobic Pseudomonas mendocina bacterium on the dissolution of Fe(III)(hydr)oxides. The research is important because metals and radionuclides that adsorb to Fe(III)(hydr)oxides could potentially be remobilized by dissolving bacteria. We showed that P. mendocina is capable of dissolving Fe-bearing minerals by a variety of mechanisms, including production of siderophores, pH changes, and formation of reductants. The production of siderophores by P. mendocina was quantified under a variety of growth conditions. Finally, we demonstrated that microbial siderophores may adsorb to and enhance dissolution of clay minerals.

  4. Ethanol production with Saccharomyces cerevisiae under aerobic conditions at different potassium concentrations

    SciTech Connect

    Wuempelmann, M.; Kjaergaard, L.; Joergensen, B.B.

    1984-01-01

    The specific ethanol productivity with Saccharomyces cerevisiae grown aerobicly in a chemostat was found to be highly dependent on the ratio of intracellular to extracellular potassium concentration through variations in the energy consumption used for maintenance of the concentration gradient of potassium across the cell membrane. The specific ethanol productivity progressively rose from 0 to 20 mmol h/sup -1/g/sup -1/ cell dry matter at a growth rate of 0.17 h/sup -1/ when the ratio of intracellular to extracellular potassium concentration was increased from 10 to 80. The ethanol production under potassium limited growth conditions was caused neither by a reduction in the specific respiratory activity nor by variations in the potassium content in cell dry matter. Results which strongly suggest that ethanol production under potassium limited growth conditions is brought about by changes in the ratio of pyruvate oxidase to pyruvate decarboxylase activity through changes in the intracellular pyruvate concentration are presented.

  5. Effects of a Rebound Exercise Training Program on Aerobic Capacity and Body Composition.

    ERIC Educational Resources Information Center

    Tomassoni, Teresa L.; And Others

    1985-01-01

    This study was designed to determine if aerobic dancing on rebound exercise equipment (minitrampolines) is an effective way to improve aerobic capacity and body composition. Although aerobic capacity improved, percent body fat did not change. Results were similar to those produced by conventional aerobic dance programs of like intensity. (MT)

  6. Issues of Health, Appearance and Physical Activity in Aerobic Classes for Women

    ERIC Educational Resources Information Center

    D'Abundo, Michelle Lee

    2009-01-01

    The purpose of this research was to explore what appearance-focused messages were conveyed by aerobic instructors in aerobic classes for women. This qualitative research was influenced by the concept of wellness and how feminist pedagogy can be applied to promote individuals' well-being in aerobic classes. The practices of five aerobic instructors…

  7. Association of G197 polymorphism of IL-17A gene with myocardial remodeling and aerobic performance in athletes.

    PubMed

    Lifanov, A D; Khadyeva, M N; Demenev, S V; Knyazev, A N; Babushkin, Yu A; Astashina, E E

    2014-09-01

    We studied the relationship between G197A polymorphism of IL-17A gene and changes in morphometric echocardiography parameters and physiological parameters in skiers (19 examinees). Genotyping was performed by restriction fragment length polymorphism analysis and echocardiography using a Nemio MX ultrasound scanner (Toshiba). Association of 197A allele of IL-17A gene with low myocardial growth and high aerobic performance of athletes was demonstrated. PMID:25257435

  8. Influence of dopants on defect formation in GaN

    SciTech Connect

    Liliental-Weber, Z.; Jasinski, J.; Benamara, M.; Grzegory, I.; Porowski, S.; Lampert, D.J.H.; Eiting, C.J.; Dupuis R.D.

    2001-10-15

    Influence of p-dopants (Mg and Be) on the structure of GaN has been studied using Transmission Electron Microscopy (TEM). Bulk GaN:Mg and GaN:Be crystals grown by a high pressure and high temperature process and GaN:Mg grown by metal-organic chemical-vapor deposition (MOCVD) have been studied. Structural dependence on growth polarity was observed in the bulk crystals. Spontaneous ordering in bulk GaN:Mg on c-plane (formation of Mg-rich planar defects with characteristics of inversion domains) was observed for growth in the N to Ga polar direction (N polarity). On the opposite site of the crystal (growth in the Ga to N polar direction) Mg-rich pyramidal defects empty inside (pinholes) were observed. Both these defects were also observed in MOCVD grown crystals. Pyramidal defects were also observed in the bulk GaN:Be crystals.

  9. Birth Defects. Matrix No. 2.

    ERIC Educational Resources Information Center

    Brent, Robert L.

    This report discusses the magnitude of the problem of birth defects, outlines advances in the birth defects field in the past decade, and identifies those areas where research is needed for the prevention, treatment, and management of birth defects. The problem of birth defects has consumed a greater portion of our health care resources because of…

  10. Prediction of Maximum Aerobic Power in Untrained Females

    ERIC Educational Resources Information Center

    Dolgener, Forrest A.

    1978-01-01

    The author presents an equation for predicting maximum aerobic power in untrained females from values of percent body fat, weight, and submaximal values of heart rate, respiratory quotient, and expired gas. (MJB)

  11. Saline storage of aerobic granules and subsequent reactivation.

    PubMed

    Wan, Chunli; Lee, Duu-Jong; Yang, Xue; Wang, Yayi; Lin, Lin

    2014-11-01

    Loss of structural stability and bioactivity during long-term storage and operation is primary challenge to field applications of aerobic granular processes. This study for the first time stored aerobic granules in 5%w/w NaCl solution at 4°C for 187d. The stored granules were then successfully reactivated and used for 85d in sequencing batch reactors (SBR) and continuous-flow reactors (CFR) at varying levels of chemical oxygen demand (COD). High-throughput sequencing results reveal that Thauera sp., Paracoccus sp., and Nitrosomonas sp. were the predominant in the stored aerobic granules, and Pseudoxanthomonas sp. accumulated during the reactivation process. Saline storage, in which cells are in an unculturable state by saline stress, is a promising storage process for aerobic granules. PMID:25270079

  12. Aerobic capacity is correlated with the ranking of boxers.

    PubMed

    Bruzas, Vidas; Stasiulis, Arvydas; Cepulenas, Algirdas; Mockus, Pranas; Statkeviciene, Birute; Subacius, Vitalijus

    2014-08-01

    The goal was to assess the aerobic capacity of boxers and its relation with sport mastery. Participants were 12 boxers from the Lithuanian national team (VO₂max - 58.03 ± 3.00 ml/kg/min) of different weight classes. Their sport mastery ranking was established according to their achieved results during the last years of participation in amateur boxing contests. In a graduated treadmill running test, the boxers' aerobic capacity indices were established. Running speed at first and second ventilatory thresholds, VO₂max, and maximal oxygen pulse had moderate to strong correlations with the boxers' sport mastery ranking. Aerobic capacity is an important fitness component of boxers in all weight categories. Special attention should be paid to development of cardiac capacity in the boxers' training processes, as with aerobic power and anaerobic threshold training. PMID:25153738

  13. Improved RDX detoxification with starch addition using a novel nitrogen-fixing aerobic microbial consortium from soil contaminated with explosives.

    PubMed

    Khan, Muhammad Imran; Yang, Jihoon; Yoo, Byungun; Park, Joonhong

    2015-04-28

    In this work, we developed and characterized a novel nitrogen-fixing aerobic microbial consortium for the complete detoxification of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX). Aerobic RDX biodegradation coupled with microbial growth and nitrogen fixation activity were effectively stimulated by the co-addition of starch and RDX under nitrogen limiting conditions. In the starch-stimulated nitrogen-fixing RDX degradative consortium, the RDX degradation activity was correlated with the xplA and nifH gene copy numbers, suggesting the involvement of nitrogen fixing populations in RDX biodegradation. Formate, nitrite, nitrate, and ammonia were detected as aerobic RDX degradation intermediates without the accumulation of any nitroso-derivatives or NDAB (4-nitro-2,4-diazabutanal), indicating nearly complete mineralization. Pyrosequencing targeting the bacterial 16S rRNA genes revealed that the Rhizobium, Rhizobacter and Terrimonas population increased as the RDX degradation activity increased, suggesting their involvement in the degradation process. These findings imply that the nitrogen-fixing aerobic RDX degrading consortium is a valuable microbial resource for improving the detoxification of RDX-contaminated soil or groundwater, especially when combined with rhizoremediation. PMID:25661171

  14. Aerobic exercise and endurance: improving fitness for health benefits.

    PubMed

    Wilmore, Jack H

    2003-05-01

    Clinicians who understand how the body responds to exercise, how aerobic training improves cardiovascular fitness, and the benefits and principles of prescribing aerobic exercise can effectively encourage patients to become active and optimize programs for those already active. Patients who are active at an early age and who continue to enjoy active lifestyles as adults will attenuate the normal losses in cardiovascular endurance, strength, and flexibility that accompany aging and sedentary living, thereby maintaining greater independence throughout their life spans. PMID:20086470

  15. Influence of oval defects on transport properties in high-mobility two-dimensional electron gases

    NASA Astrophysics Data System (ADS)

    Bockhorn, L.; Velieva, A.; Hakim, S.; Wagner, T.; Rugeramigabo, E. P.; Schuh, D.; Reichl, C.; Wegscheider, W.; Haug, R. J.

    2016-02-01

    Rare macroscopic growth defects next to a two-dimensional electron gas influence transport properties and cause a negative magnetoresistance. On the basis of this, we show that the number of oval defects seen on the material surface is comparable with the density of macroscopic growth defects determined from the negative magnetoresistance. We examine several materials with different densities of oval defects nS which were grown in one cycle under the same conditions to verify our observations. Paradoxically, the material with the largest number of oval defects has also the highest electron mobility.

  16. Surface Structure of Aerobically Oxidized Diamond Nanocrystals

    DOE PAGESBeta

    Wolcott, Abraham; Schiros, Theanne; Trusheim, Matthew E.; Chen, Edward H.; Nordlund, Dennis; Diaz, Rosa E.; Gaaton, Ophir; Englund, Dirk; Owen, Jonathan S.

    2014-10-27

    Here we investigate the aerobic oxidation of high-pressure, high-temperature nanodiamonds (5–50 nm dimensions) using a combination of carbon and oxygen K-edge X-ray absorption, wavelength-dependent X-ray photoelectron, and vibrational spectroscopies. Oxidation at 575 °C for 2 h eliminates graphitic carbon contamination (>98%) and produces nanocrystals with hydroxyl functionalized surfaces as well as a minor component (<5%) of carboxylic anhydrides. The low graphitic carbon content and the high crystallinity of HPHT are evident from Raman spectra acquired using visible wavelength excitation (λexcit = 633 nm) as well as carbon K-edge X-ray absorption spectra where the signature of a core–hole exciton is observed.more » Both spectroscopic features are similar to those of chemical vapor deposited (CVD) diamond but differ significantly from the spectra of detonation nanodiamond. Lastly, we discuss the importance of these findings to the functionalization of nanodiamond surfaces for biological labeling applications.« less

  17. Maximal aerobic exercise following prolonged sleep deprivation.

    PubMed

    Goodman, J; Radomski, M; Hart, L; Plyley, M; Shephard, R J

    1989-12-01

    The effect of 60 h without sleep upon maximal oxygen intake was examined in 12 young women, using a cycle ergometer protocol. The arousal of the subjects was maintained by requiring the performance of a sequence of cognitive tasks throughout the experimental period. Well-defined oxygen intake plateaus were obtained both before and after sleep deprivation, and no change of maximal oxygen intake was observed immediately following sleep deprivation. The endurance time for exhausting exercise also remained unchanged, as did such markers of aerobic performance as peak exercise ventilation, peak heart rate, peak respiratory gas exchange ratio, and peak blood lactate. However, as in an earlier study of sleep deprivation with male subjects (in which a decrease of treadmill maximal oxygen intake was observed), the formula of Dill and Costill (4) indicated the development of a substantial (11.6%) increase of estimated plasma volume percentage with corresponding decreases in hematocrit and red cell count. Possible factors sustaining maximal oxygen intake under the conditions of the present experiment include (1) maintained arousal of the subjects with no decrease in peak exercise ventilation or the related respiratory work and (2) use of a cycle ergometer rather than a treadmill test with possible concurrent differences in the impact of hematocrit levels and plasma volume expansion upon peak cardiac output and thus oxygen delivery to the working muscles. PMID:2628360

  18. Dancing the aerobics ''hearing loss'' choreography

    NASA Astrophysics Data System (ADS)

    Pinto, Beatriz M.; Carvalho, Antonio P. O.; Gallagher, Sergio

    2002-11-01

    This paper presents an overview of gymnasiums' acoustic problems when used for aerobics exercises classes (and similar) with loud noise levels of amplified music. This type of gymnasium is usually a highly reverberant space, which is a consequence of a large volume surrounded by hard surfaces. A sample of five schools in Portugal was chosen for this survey. Noise levels in each room were measured using a precision sound level meter, and analyzed to calculate the standardized daily personal noise exposure levels (LEP,d). LEP,d values from 79 to 91 dB(A) were found to be typical values in this type of room, inducing a health risk for its occupants. The reverberation time (RT) values were also measured and compared with some European legal requirements (Portugal, France, and Belgium) for nearly similar situations. RT values (1 kHz) from 0.9 s to 2.8 s were found. These reverberation time values clearly differentiate between good and acoustically inadequate rooms. Some noise level and RT limits for this type of environment are given and suggestions for the improvement of the acoustical environment are shown. Significant reductions in reverberation time values and noise levels can be obtained by simple measures.

  19. Late Archean rise of aerobic microbial ecosystems

    PubMed Central

    Eigenbrode, Jennifer L.; Freeman, Katherine H.

    2006-01-01

    We report the 13C content of preserved organic carbon for a 150 million-year section of late Archean shallow and deepwater sediments of the Hamersley Province in Western Australia. We find a 13C enrichment of ≈10‰ in organic carbon of post-2.7-billion-year-old shallow-water carbonate rocks relative to deepwater sediments. The shallow-water organic-carbon 13C content has a 29‰ range in values (−57 to −28‰), and it contrasts with the less variable but strongly 13C-depleted (−40 to −45‰) organic carbon in deepwater sediments. The 13C enrichment likely represents microbial habitats not as strongly influenced by assimilation of methane or other 13C-depleted substrates. We propose that continued oxidation of shallow settings favored the expansion of aerobic ecosystems and respiring organisms, and, as a result, isotopic signatures of preserved organic carbon in shallow settings approached that of photosynthetic biomass. Facies analysis of published carbon-isotopic records indicates that the Hamersley shallow-water signal may be representative of a late Archean global signature and that it preceded a similar, but delayed, 13C enrichment of deepwater deposits. The data suggest that a global-scale expansion of oxygenated habitats accompanied the progression away from anaerobic ecosystems toward respiring microbial communities fueled by oxygenic photosynthesis before the oxygenation of the atmosphere after 2.45 billion years ago. PMID:17043234

  20. Personality, Metabolic Rate and Aerobic Capacity

    PubMed Central

    Terracciano, Antonio; Schrack, Jennifer A.; Sutin, Angelina R.; Chan, Wayne; Simonsick, Eleanor M.; Ferrucci, Luigi

    2013-01-01

    Personality traits and cardiorespiratory fitness in older adults are reliable predictors of health and longevity. We examined the association between personality traits and energy expenditure at rest (basal metabolic rate) and during normal and maximal sustained walking. Personality traits and oxygen (VO2) consumption were assessed in 642 participants from the Baltimore Longitudinal Study of Aging. Results indicate that personality traits were mostly unrelated to resting metabolic rate and energy expenditure at normal walking pace. However, those who scored lower on neuroticism (r =  −0.12) and higher on extraversion (r = 0.11), openness (r = 0.13), and conscientiousness (r = 0.09) had significantly higher energy expenditure at peak walking pace. In addition to greater aerobic capacity, individuals with a more resilient personality profile walked faster and were more efficient in that they required less energy per meter walked. The associations between personality and energy expenditure were not moderated by age or sex, but were in part explained by the proportion of fat mass. In conclusion, differences in personality may matter the most during more challenging activities that require cardiorespiratory fitness. These findings suggest potential pathways that link personality to health outcomes, such as obesity and longevity. PMID:23372763