Influence of substrate surface loading on the kinetic behaviour of aerobic granules.

PubMed

Liu, Yu; Liu, Yong-Qiang; Wang, Zhi-Wu; Yang, Shu-Fang; Tay, Joo-Hwa

2005-06-01

In the aerobic granular sludge reactor, the substrate loading is related to the size of the aerobic granules cultivated. This study investigated the influence of substrate surface loading on the growth and substrate-utilization kinetics of aerobic granules. Results showed that microbial surface growth rate and surface biodegradation rate are fairly related to the substrate surface loading by the Monod-type equation. In this study, both the theoretical maximum growth yield and the Pirt maintenance coefficient were determined. It was found that the estimated theoretical maximum growth yield of aerobic granules was as low as 0.2 g biomass g(-1) chemical oxygen demand (COD) and 10-40% of input substrate-COD was consumed through the maintenance metabolism, while experimental results further showed that the unit oxygen uptake by aerobic granules was 0.68 g oxygen g(-1) COD, which was much higher than that reported in activated sludge processes. Based on the growth yield and unit oxygen uptake determined, an oxidative assimilation equation of acetate-fed aerobic granules was derived; and this was confirmed by respirometric tests. In aerobic granular culture, about 74% of the input substrate-carbon was converted to carbon dioxide. The growth yield of aerobic granules was three times lower than that of activated sludge. It is likely that high carbon dioxide production is the main cause of the low growth yield of aerobic granules, indicating a possible energy uncoupling in aerobic granular culture.

Aerobic Growth on Nitroglycerin as the Sole Carbon, Nitrogen, and Energy Source by a Mixed Bacterial Culture

PubMed Central

Accashian, John V.; Vinopal, Robert T.; Kim, Byung-Joon; Smets, Barth F.

1998-01-01

Nitroglycerin (glycerol trinitrate [GTN]), an explosive and vasodilatory compound, was metabolized by mixed microbial cultures from aeration tank sludge previously exposed to GTN. Aerobic enrichment cultures removed GTN rapidly in the absence of a supplemental carbon source. Complete denitration of GTN, provided as the sole C and N source, was observed in aerobic batch cultures and proceeded stepwise via the dinitrate and mononitrate isomers, with successive steps occurring at lower rates. The denitration of all glycerol nitrate esters was found to be concomitant, and 1,2-glycerol dinitrate (1,2-GDN) and 2-glycerol mononitrate (2-GMN) were the primary GDN and GMN isomers observed. Denitration of GTN resulted in release of primarily nitrite-N, indicating a reductive denitration mechanism. Biomass growth at the expense of GTN was verified by optical density and plate count measurements. The kinetics of GTN biotransformation were 10-fold faster than reported for complete GTN denitration under anaerobic conditions. A maximum specific growth rate of 0.048 ± 0.005 h−1 (mean ± standard deviation) was estimated for the mixed culture at 25°C. Evidence of GTN toxicity was observed at GTN concentrations above 0.3 mM. To our knowledge, this is the first report of complete denitration of GTN used as a primary growth substrate by a bacterial culture under aerobic conditions. PMID:9726874

Correlating defect density with growth time in continuous graphene films.

PubMed

Kang, Cheong; Jung, Da Hee; Nam, Ji Eun; Lee, Jin Seok

2014-12-01

We report that graphene flakes and films which were synthesized by copper-catalyzed atmospheric pressure chemical vapor deposition (APCVD) method using a mixture of Ar, H2, and CH4 gases. It was found that variations in the reaction parameters, such as reaction temperature, annealing time, and growth time, influenced the domain size of as-grown graphene. Besides, the reaction parameters influenced the number of layers, degree of defects and uniformity of the graphene films. The increase in growth temperature and annealing time tends to accelerate the graphene growth rate and increase the diffusion length, respectively, thereby increasing the average size of graphene domains. In addition, we confirmed that the number of pinholes reduced with increase in the growth time. Micro-Raman analysis of the as-grown graphene films confirmed that the continuous graphene monolayer film with low defects and high uniformity could be obtained with prolonged reaction time, under the appropriate annealing time and growth temperature.

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.

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.

Learning defects in Drosophila growth restricted chico mutants are caused by attenuated adenylyl cyclase activity.

PubMed

Naganos, Shintaro; Ueno, Kohei; Horiuchi, Junjiro; Saitoe, Minoru

2016-04-06

Reduced insulin/insulin-like growth factor signaling (IIS) is a major cause of symmetrical intrauterine growth retardation (IUGR), an impairment in cell proliferation during prenatal development that results in global growth defects and mental retardation. In Drosophila, chico encodes the only insulin receptor substrate. Similar to other animal models of IUGR, chico mutants have defects in global growth and associative learning. However, the physiological and molecular bases of learning defects caused by chico mutations, and by symmetrical IUGR, are not clear. In this study, we found that chico mutations impair memory-associated synaptic plasticity in the mushroom bodies (MBs), neural centers for olfactory learning. Mutations in chico reduce expression of the rutabaga-type adenylyl cyclase (rut), leading to decreased cAMP synthesis in the MBs. Expressing a rut (+) transgene in the MBs restores memory-associated plasticity and olfactory associative learning in chico mutants, without affecting growth. Thus chico mutations disrupt olfactory learning, at least in part, by reducing cAMP signaling in the MBs. Our results suggest that some cognitive defects associated with reduced IIS may occur, independently of developmental defects, from acute reductions in cAMP signaling.

Study on growth techniques and macro defects of large-size Nd:YAG laser crystal

NASA Astrophysics Data System (ADS)

Quan, Jiliang; Yang, Xin; Yang, Mingming; Ma, Decai; Huang, Jinqiang; Zhu, Yunzhong; Wang, Biao

2018-02-01

Large-size neodymium-doped yttrium aluminum garnet (Nd:YAG) single crystals were grown by the Czochralski method. The extinction ratio and wavefront distortion of the crystal were tested to determine the optical homogeneity. Moreover, under different growth conditions, the macro defects of inclusion, striations, and cracking in the as-grown Nd:YAG crystals were analyzed. Specifically, the inclusion defects were characterized using scanning electron microscopy and energy dispersive spectroscopy. The stresses of growth striations and cracking were studied via a parallel plane polariscope. These results demonstrate that improper growth parameters and temperature fields can enhance defects significantly. Thus, by adjusting the growth parameters and optimizing the thermal environment, high-optical-quality Nd:YAG crystals with a diameter of 80 mm and a total length of 400 mm have been obtained successfully.

The effect of aerobic exercise training on growth performance, digestive enzyme activities and postprandial metabolic response in juvenile qingbo (Spinibarbus sinensis).

PubMed

Li, Xiu-Ming; Yu, Li-Juan; Wang, Chuan; Zeng, Ling-Qing; Cao, Zhen-Dong; Fu, Shi-Jian; Zhang, Yao-Guang

2013-09-01

Continual swimming exercise usually promotes growth in fish at a moderate water velocity. We hypothesized that the improvement in growth in exercise-trained fish may be accompanied by increases in digestive enzyme activity, respiratory capacity and, hence, postprandial metabolism. Juvenile qingbo fish (Spinibarbus sinensis) were subjected to aerobic training for 8weeks at a water velocity of control (3cms(-1)), 1, 2 and 4 body length (bl)s(-1) at a constant temperature of 25°C. The feed intake (FI), food conversion rate (FCR), specific growth rate (SGR), whole-body composition, trypsin and lipase activities, maximal oxygen consumption (M˙O2max) and postprandial M˙O2 response were measured at the end of the training period. Aerobic exercise training induced a significant increase in FI compared with the control group, while the FCR of the 4bls(-1) group was significantly lower than for the other three groups (P<0.05). The 1 and 2bls(-1) groups showed a significantly higher SGR over the control group (P<0.05). The whole-body fat and protein contents were significantly altered after aerobic exercise training (P<0.05). Furthermore, aerobic exercise training elevated the activity of both trypsin and lipase in the hepatopancreas and intestinal tract of juvenile S. sinensis. The M˙O2max of the 4bls(-1) training group was significantly higher than for the control group. The resting M˙O2 (M˙O2rest) and peak postprandial M˙O2 (M˙O2peak) in the three training groups were significantly higher than in the control group (P<0.05). Time to M˙O2peak was significantly shorter in the 1, 2 and 4bls(-1) training groups compared with the control group, while exercise training showed no effect on SDA (specific dynamic action) duration, factorial metabolic scope, energy expended on SDA and the SDA coefficient when compared to the control group. These data suggest that (1) the optimum water velocity for the growth of juvenile S. sinensis occurred at approximately 2.4bls(-1); (2

The aerobic activity of metronidazole against anaerobic bacteria.

PubMed

Dione, Niokhor; Khelaifia, Saber; Lagier, Jean-Christophe; Raoult, Didier

2015-05-01

Recently, the aerobic growth of strictly anaerobic bacteria was demonstrated using antioxidants. Metronidazole is frequently used to treat infections caused by anaerobic bacteria; however, to date its antibacterial activity was only tested in anaerobic conditions. Here we aerobically tested using antioxidants the in vitro activities of metronidazole, gentamicin, doxycycline and imipenem against 10 common anaerobic and aerobic bacteria. In vitro susceptibility testing was performed by the disk diffusion method, and minimum inhibitory concentrations (MICs) were determined by Etest. Aerobic culture of the bacteria was performed at 37°C using Schaedler agar medium supplemented with 1mg/mL ascorbic acid and 0.1mg/mL glutathione; the pH was adjusted to 7.2 by 10M KOH. Growth of anaerobic bacteria cultured aerobically using antioxidants was inhibited by metronidazole after 72h of incubation at 37°C, with a mean inhibition diameter of 37.76mm and an MIC of 1μg/mL; however, strains remained non-sensitive to gentamicin. No growth inhibition of aerobic bacteria was observed after 24h of incubation at 37°C with metronidazole; however, inhibition was observed with doxycycline and imipenem used as controls. These results indicate that bacterial sensitivity to metronidazole is not related to the oxygen tension but is a result of the sensitivity of the micro-organism. In future, both culture and antibiotic susceptibility testing of strictly anaerobic bacteria will be performed in an aerobic atmosphere using antioxidants in clinical microbiology laboratories. Copyright © 2015 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

Genes essential for phototrophic growth by a purple alphaproteobacterium: Genes for phototrophic growth

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Jianming; Yin, Liang; Lessner, Faith H.

Anoxygenic purple phototrophic bacteria have served as important models for studies of photophosphorylation. The pigment-protein complexes responsible for converting light energy to ATP are relatively simple and these bacteria can grow heterotrophically under aerobic conditions, thus allowing for the study of mutants defective in photophosphorylation. In the past, genes responsible for anoxygenic phototrophic growth have been identified in a number of different bacterial species. Here we systematically studied the genetic basis for this metabolism by using Tn-seq to identify genes essential for the anaerobic growth of the purple bacterium Rhodopseudomonas palustris on acetate in light. We identified 171 genes requiredmore » for growth in this condition, 35 of which are annotated as photosynthesis genes. Among these are a few new genes not previously shown to be essential for phototrophic growth. We verified the essentiality of many of the genes we identified by analyzing the phenotypes of mutants we generated by Tn mutagenesis that had altered pigmentation. We used directed mutagenesis to verify that the R. palustris NADH:quinone oxidoreductase complex IE is essential for phototrophic growth. As a complement to the genetic data, we carried out proteomics experiments in which we found that 429 proteins were present in significantly higher amounts in cells grown anaerobically in light compared to aerobically. Among these were proteins encoded by subset of the phototrophic growth-essential genes.« less

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

Storage and growth of denitrifiers in aerobic granules: part I. model development.

PubMed

Ni, Bing-Jie; Yu, Han-Qing

2008-02-01

A mathematical model, based on the Activated Sludge Model No.3 (ASM3), is developed to describe the storage and growth activities of denitrifiers in aerobic granules under anoxic conditions. In this model, mass transfer, hydrolysis, simultaneous anoxic storage and growth, anoxic maintenance, and endogenous decay are all taken into account. The model established is implemented in the well-established AQUASIM simulation software. A combination of completely mixed reactor and biofilm reactor compartments provided by AQUASIM is used to simulate the mass transport and conversion processes occurring in both bulk liquid and granules. The modeling results explicitly show that the external substrate is immediately utilized for storage and growth at feast phase. More external substrates are diverted to storage process than the primary biomass production process. The model simulation indicates that the nitrate utilization rate (NUR) of granules-based denitrification process includes four linear phases of nitrate reduction. Furthermore, the methodology for determining the most important parameter in this model, that is, anoxic reduction factor, is established. (c) 2007 Wiley Periodicals, Inc.

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.

LDHA in neuroblastoma is associated with poor outcome and its depletion decreases neuroblastoma growth independent of aerobic glycolysis.

PubMed

Dorneburg, Carmen; Fischer, Matthias; Barth, Thomas F E; Mueller-Klieser, Wolfgang; Hero, Barbara; Gecht, Judith; Carter, Daniel R; De Preter, Katleen; Mayer, Benjamin; Christner, Lisa; Speleman, Frank; Marshall, Glenn M; Debatin, Klaus-Michael; Beltinger, Christian

2018-06-20

To investigate whether lactate dehydrogenase A (LDHA), an important component of the LDH tetramer crucial for aerobic glycolysis, is associated with patient outcome and constitutes a therapeutic target in neuroblastoma (NB). Expression of LDHA mRNA and protein was determined in 709 and 110 NB patient samples, respectively, and correlated to survival and risk factors. LDHA and LDHB were depleted in human NB cell lines by CRISPR/Cas9 and shRNA, respectively, and aerobic glycolysis, clonogenicity and tumorigenicity were determined. Expression of LDHA in relation to MYCN was measured in NB cell lines and in the TH-MYCN NB mouse model. Expression of LDHA, both on the mRNA and the protein level, was significantly and independently associated with decreased patient survival. Predominant cytoplasmic localization of LDHA protein was associated with poor outcome. Amplification and expression of MYCN did not correlate with expression of LDHA in NB cell lines or TH-MYCN mice, respectively. Knockout of LDHA inhibited clonogenicity, tumorigenicity and tumor growth without abolishing LDH activity or significantly decreasing aerobic glycolysis. Concomitant depletion of LDHA and the isoform LDHB ablated clonogenicity while not abrogating LDH activity or decreasing aerobic glycolysis. The isoform LDHC was not expressed. High expression of LDHA is independently associated with poor outcome of NB and NB cells can be inhibited by depletion of LDHA or LDHB. This inhibition appears to be unrelated to LDH activity and aerobic glycolysis. Thus, investigations of inhibitory mechanisms beyond attenuation of aerobic glycolysis are warranted, both in NB and normal cells. Copyright ©2018, American Association for Cancer Research.

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.

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

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

DOE PAGES

Dey, Sanchita; Mardinly, John; Wang, Yongqiang; ...

2016-05-27

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, in this study, we tested this concept in nanocrystalline zirconia doped with lanthanum. Although the dopant is observedmore » 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.« less

A Chlorhexidine Solution Reduces Aerobic Organism Growth in Operative Splash Basins in a Randomized Controlled Trial.

PubMed

Lindgren, Kevin E; Pelt, Christopher E; Anderson, Mike B; Peters, Christopher L; Spivak, Emily S; Gililland, Jeremy M

2018-01-01

Despite recommendations against the use of splash basins, due to the potential of bacterial contamination, our observation has been that they continue to be used in operating theaters. In hopes of decontaminating the splash basin, we sought to determine if the addition of chlorhexidine gluconate (CHG) would eliminate aerobic bacterial growth within the splash basin. After Institutional Review Board approval, we began enrollment in a randomized controlled trial comparing 2 splash basin solutions. Splash basins (n = 111) were randomized to either the standard of care (control) solution of sterile water or the experimental solution containing 0.05% CHG. One 20 mL aliquot was taken from the basin at the end of the surgical case and delivered to an independent laboratory. Samples were plated on tryptic soy agar (medium) and incubated at 30°C-35°C to encourage growth. After 48-72 hours, the agar plates were examined for growth and a standard plate count of aerobic cultures was performed. The sterile water group was found to have bacterial growth in 9% of samples compared to no growth in the CHG group (P = .045). The organisms included Micrococcus luteus, Staphylococcus hominis, Gram-variable coccobacilli, and unidentifiable Gram-positive rods. Given the safety and efficacy of a concentration of 0.05% CHG in reducing the bacterial contamination in the operative splash basin, it would seem that if the practice of using a splash basin in the operating theater is to be continued, the addition of an antiseptic solution such as that studied here should be considered. Copyright © 2017 Elsevier Inc. All rights reserved.

Defects in High Speed Growth of EFG Silicon Ribbon

NASA Technical Reports Server (NTRS)

Rao, C. V. H. N.; Cretella, M. C.

1984-01-01

Silicon ribbons grown by the Edge-defined Film-fed Growth (EFG) technique exhibit a characteristic defect structure typified by twins, dislocations, grain boundaries and silicon carbide inclusions. As growth speed is increased from less than 2.5 cm per minute, the structural details change. The major difference between the ribbons grown at speeds below and above 2.5 cm per minute is in the generation of a cellular structure at the higher growth speeds, observable in the ribbon cross section. The presence of the cross sectional structure leads, in general, to a reduction in cell performance. Models to explain the formation of such a cross sectional structure are presented and discussed.

Modeling the growth of Salmonella in raw poultry stored under aerobic conditions.

PubMed

Dominguez, Silvia A; Schaffner, Donald W

2008-12-01

The presence of Salmonella in raw poultry is a well-recognized risk factor for foodborne illness. The objective of this study was to develop and validate a mathematical model that predicts the growth of Salmonella in raw poultry stored under aerobic conditions at a variety of temperatures. One hundred twelve Salmonella growth rates were extracted from 12 previously published studies. These growth rates were used to develop a square-root model relating the growth rate of Salmonella to storage temperature. Model predictions were compared to growth rate measurements collected in our laboratory for four poultry-specific Salmonella strains (two antibiotic-resistant and two nonresistant strains) inoculated onto raw chicken tenderloins. Chicken was inoculated at two levels (10(3) CFU/cm2 and < or = 10 CFU/cm2) and incubated at temperatures ranging from 10 to 37 degrees C. Visual inspection of the data, bias and accuracy factors, and comparison with two other published models were used to analyze the performance of the new model. Neither antibiotic resistance nor inoculum size affected Salmonella growth rates. The presence of spoilage microflora did not appear to slow the growth of Salmonella. Our model provided intermediate predicted growth rates when compared with the two other published models. Our model predicted slightly faster growth rates than those observed in inoculated chicken in the temperature range of 10 to 28 degrees C but slightly slower growth rates than those observed between 30 and 37 degrees C. Slightly negative bias factors were obtained in every case (-5 to -3%); however, application of the model may be considered fail-safe for storage temperatures below 28 degrees C.

The Yfe and Feo transporters are involved in microaerobic growth and virulence of Yersinia pestis in bubonic plague.

PubMed

Fetherston, Jacqueline D; Mier, Ildefonso; Truszczynska, Helena; Perry, Robert D

2012-11-01

The Yfe/Sit and Feo transport systems are important for the growth of a variety of bacteria. In Yersinia pestis, single mutations in either yfe or feo result in reduced growth under static (limited aeration), iron-chelated conditions, while a yfe feo double mutant has a more severe growth defect. These growth defects were not observed when bacteria were grown under aerobic conditions or in strains capable of producing the siderophore yersiniabactin (Ybt) and the putative ferrous transporter FetMP. Both fetP and a downstream locus (flp for fet linked phenotype) were required for growth of a yfe feo ybt mutant under static, iron-limiting conditions. An feoB mutation alone had no effect on the virulence of Y. pestis in either bubonic or pneumonic plague models. An feo yfe double mutant was still fully virulent in a pneumonic plague model but had an ∼90-fold increase in the 50% lethal dose (LD(50)) relative to the Yfe(+) Feo(+) parent strain in a bubonic plague model. Thus, Yfe and Feo, in addition to Ybt, play an important role in the progression of bubonic plague. Finally, we examined the factors affecting the expression of the feo operon in Y. pestis. Under static growth conditions, the Y. pestis feo::lacZ fusion was repressed by iron in a Fur-dependent manner but not in cells grown aerobically. Mutations in feoC, fnr, arcA, oxyR, or rstAB had no significant effect on transcription of the Y. pestis feo promoter. Thus, the factor(s) that prevents repression by Fur under aerobic growth conditions remains to be identified.

The Yfe and Feo Transporters Are Involved in Microaerobic Growth and Virulence of Yersinia pestis in Bubonic Plague

PubMed Central

Fetherston, Jacqueline D.; Mier, Ildefonso; Truszczynska, Helena

2012-01-01

The Yfe/Sit and Feo transport systems are important for the growth of a variety of bacteria. In Yersinia pestis, single mutations in either yfe or feo result in reduced growth under static (limited aeration), iron-chelated conditions, while a yfe feo double mutant has a more severe growth defect. These growth defects were not observed when bacteria were grown under aerobic conditions or in strains capable of producing the siderophore yersiniabactin (Ybt) and the putative ferrous transporter FetMP. Both fetP and a downstream locus (flp for fet linked phenotype) were required for growth of a yfe feo ybt mutant under static, iron-limiting conditions. An feoB mutation alone had no effect on the virulence of Y. pestis in either bubonic or pneumonic plague models. An feo yfe double mutant was still fully virulent in a pneumonic plague model but had an ∼90-fold increase in the 50% lethal dose (LD50) relative to the Yfe+ Feo+ parent strain in a bubonic plague model. Thus, Yfe and Feo, in addition to Ybt, play an important role in the progression of bubonic plague. Finally, we examined the factors affecting the expression of the feo operon in Y. pestis. Under static growth conditions, the Y. pestis feo::lacZ fusion was repressed by iron in a Fur-dependent manner but not in cells grown aerobically. Mutations in feoC, fnr, arcA, oxyR, or rstAB had no significant effect on transcription of the Y. pestis feo promoter. Thus, the factor(s) that prevents repression by Fur under aerobic growth conditions remains to be identified. PMID:22927049

Molecular Dynamics Study of High Symmetry Planar Defect Evolution during Growth of CdTe/CdS Films

DOE PAGES

Chavez, Jose Juan; Zhou, Xiao W.; Almeida, Sergio F.; ...

2017-12-15

The growth dynamics and evolution of intrinsic stacking faults, lamellar, and double positioning twin grain boundaries were explored using molecular dynamics simulations during the growth of CdTe homoepitaxy and CdTe/CdS heteroepitaxy. Initial substrate structures were created containing either stacking fault or one type of twin grain boundary, and films were subsequently deposited to study the evolution of the underlying defect. Results show that during homoepitaxy the film growth was epitaxial and the substrate’s defects propagated into the epilayer, except for the stacking fault case where the defect disappeared after the film thickness increased. In contrast, films grown on heteroepitaxy conditionsmore » formed misfit dislocations and grew with a small angle tilt (within ~5°) of the underlying substrate’s orientation to alleviate the lattice mismatch. Grain boundary proliferation was observed in the lamellar and double positioning twin cases. Finally, our study indicates that it is possible to influence the propagation of high symmetry planar defects by selecting a suitable substrate defect configuration, thereby controlling the film defect morphology.« less

Molecular Dynamics Study of High Symmetry Planar Defect Evolution during Growth of CdTe/CdS Films

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chavez, Jose Juan; Zhou, Xiao W.; Almeida, Sergio F.

The growth dynamics and evolution of intrinsic stacking faults, lamellar, and double positioning twin grain boundaries were explored using molecular dynamics simulations during the growth of CdTe homoepitaxy and CdTe/CdS heteroepitaxy. Initial substrate structures were created containing either stacking fault or one type of twin grain boundary, and films were subsequently deposited to study the evolution of the underlying defect. Results show that during homoepitaxy the film growth was epitaxial and the substrate’s defects propagated into the epilayer, except for the stacking fault case where the defect disappeared after the film thickness increased. In contrast, films grown on heteroepitaxy conditionsmore » formed misfit dislocations and grew with a small angle tilt (within ~5°) of the underlying substrate’s orientation to alleviate the lattice mismatch. Grain boundary proliferation was observed in the lamellar and double positioning twin cases. Finally, our study indicates that it is possible to influence the propagation of high symmetry planar defects by selecting a suitable substrate defect configuration, thereby controlling the film defect morphology.« less

Fermi Level Control of Point Defects During Growth of Mg-Doped GaN

NASA Astrophysics Data System (ADS)

Bryan, Zachary; Hoffmann, Marc; Tweedie, James; Kirste, Ronny; Callsen, Gordon; Bryan, Isaac; Rice, Anthony; Bobea, Milena; Mita, Seiji; Xie, Jinqiao; Sitar, Zlatko; Collazo, Ramón

2013-05-01

In this study, Fermi level control of point defects during metalorganic chemical vapor deposition (MOCVD) of Mg-doped GaN has been demonstrated by above-bandgap illumination. Resistivity and photoluminescence (PL) measurements are used to investigate the Mg dopant activation of samples with Mg concentration of 2 × 1019 cm-3 grown with and without exposure to ultraviolet (UV) illumination. Samples grown under UV illumination have five orders of magnitude lower resistivity values compared with typical unannealed GaN:Mg samples. The PL spectra of samples grown with UV exposure are similar to the spectra of those grown without UV exposure that were subsequently annealed, indicating a different incorporation of compensating defects during growth. Based on PL and resistivity measurements we show that Fermi level control of point defects during growth of III-nitrides is feasible.

Growth Method-Dependent and Defect Density-Oriented Structural, Optical, Conductive, and Physical Properties of Solution-Grown ZnO Nanostructures.

PubMed

Rana, Abu Ul Hassan Sarwar; Lee, Ji Young; Shahid, Areej; Kim, Hyun-Seok

2017-09-10

It is time for industry to pay a serious heed to the application and quality-dependent research on the most important solution growth methods for ZnO, namely, aqueous chemical growth (ACG) and microwave-assisted growth (MAG) methods. This study proffers a critical analysis on how the defect density and formation behavior of ZnO nanostructures (ZNSs) are growth method-dependent. Both antithetical and facile methods are exploited to control the ZnO defect density and the growth mechanism. In this context, the growth of ZnO nanorods (ZNRs), nanoflowers, and nanotubes (ZNTs) are considered. The aforementioned growth methods directly stimulate the nanostructure crystal growth and, depending upon the defect density, ZNSs show different trends in structural, optical, etching, and conductive properties. The defect density of MAG ZNRs is the least because of an ample amount of thermal energy catered by high-power microwaves to the atoms to grow on appropriate crystallographic planes, which is not the case in faulty convective ACG ZNSs. Defect-centric etching of ZNRs into ZNTs is also probed and methodological constraints are proposed. ZNS optical properties are different in the visible region, which are quite peculiar, but outstanding for ZNRs. Hall effect measurements illustrate incongruent conductive trends in both samples.

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. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Defect reduction in seeded aluminum nitride crystal growth

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bondokov, Robert T.; Morgan, Kenneth E.; Schowalter, Leo J.

2017-04-18

Bulk single crystal of aluminum nitride (AlN) having an areal planar defect density.ltoreq.100 cm.sup.-2. Methods for growing single crystal aluminum nitride include melting an aluminum foil to uniformly wet a foundation with a layer of aluminum, the foundation forming a portion of an AlN seed holder, for an AlN seed to be used for the AlN growth. The holder may consist essentially of a substantially impervious backing plate.

Defect reduction in seeded aluminum nitride crystal growth

DOEpatents

Bondokov, Robert T.; Morgan, Kenneth E.; Schowalter, Leo J.; Slack, Glen A.

2017-06-06

Bulk single crystal of aluminum nitride (AlN) having an areal planar defect density .ltoreq.100 cm.sup.-2. Methods for growing single crystal aluminum nitride include melting an aluminum foil to uniformly wet a foundation with a layer of aluminum, the foundation forming a portion of an AlN seed holder, for an AlN seed to be used for the AlN growth. The holder may consist essentially of a substantially impervious backing plate.

Defect reduction in seeded aluminum nitride crystal growth

DOEpatents

Bondokov, Robert T.; Schowalter, Leo J.; Morgan, Kenneth; Slack, Glen A; Rao, Shailaja P.; Gibb, Shawn Robert

2017-09-26

Bulk single crystal of aluminum nitride (AlN) having an areal planar defect density.ltoreq.100 cm.sup.-2. Methods for growing single crystal aluminum nitride include melting an aluminum foil to uniformly wet a foundation with a layer of aluminum, the foundation forming a portion of an AlN seed holder, for an AlN seed to be used for the AlN growth. The holder may consist essentially of a substantially impervious backing plate.

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

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

2014-05-22

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.

Defective lysosomal targeting of activated fibroblast growth factor receptor 3 in achondroplasia.

PubMed

Cho, Jay Y; Guo, Changsheng; Torello, Monica; Lunstrum, Gregory P; Iwata, Tomoko; Deng, Chuxia; Horton, William A

2004-01-13

Mutations of fibroblast growth factor receptor 3 (FGFR3) are responsible for achondroplasia (ACH) and related dwarfing conditions in humans. The pathogenesis involves constitutive activation of FGFR3, which inhibits proliferation and differentiation of growth plate chondrocytes. Here we report that activating mutations in FGFR3 increase the stability of the receptor. Our results suggest that the mutations disrupt c-Cbl-mediated ubiquitination that serves as a targeting signal for lysosomal degradation and termination of receptor signaling. The defect allows diversion of actively signaling receptors from lysosomes to a recycling pathway where their survival is prolonged, and, as a result, their signaling capacity is increased. The lysosomal targeting defect is additive to other mechanisms proposed to explain the pathogenesis of ACH.

Intrauterine growth restriction increases circulating mitochondrial DNA and Toll-like receptor 9 expression in adult offspring: could aerobic training counteract these adaptations?

PubMed

Oliveira, V; Silva Junior, S D; de Carvalho, M H C; Akamine, E H; Michelini, L C; Franco, M C

2017-04-01

It has been demonstrated that intrauterine growth restriction (IUGR) can program increase cardiometabolic risk. There are also evidences of the correlation between IUGR with low-grade inflammation and, thus can contribute to development of several cardiometabolic comorbidities. Therefore, we investigated the influence of IUGR on circulating mitochondrial DNA (mtDNA)/Toll-like receptor 9 (TLR9) and TNF-α expression in adult offspring. Considering that the aerobic training has anti-inflammatory actions, we also investigated whether aerobic training would improve these inflammatory factors. Pregnant Wistar rats received ad libitum or 50% of ad libitum diet throughout gestation. At 8 weeks of age, male offspring from both groups were randomly assigned to control, trained control, restricted and trained restricted. Aerobic training protocol was performed on a treadmill and after that, we evaluated circulating mtDNA, cardiac protein expression of TLR9, plasma and cardiac TNF-α levels, and left ventricle (LV) mass. We found that IUGR promoted an increase in the circulating mtDNA, TLR9 expression and plasma TNF-α levels. Further, our results revealed that aerobic training can restore mtDNA/TLR9 content and plasma levels of TNF-α among restricted rats. The cardiac TNF-α content and LV mass were not influenced either by IUGR or aerobic training. In conclusion, IUGR can program mtDNA/TLR9 content, which may lead to high levels of TNF-α. However, aerobic training was able to normalize these alterations. These findings evidenced that the association of IUGR and aerobic training seems to exert an important interaction effect regarding pro-inflammatory condition and, aerobic training may be used as a strategy to reduce deleterious adaptations in IUGR offspring.

Top 10 Research Questions Related to Youth Aerobic Fitness

ERIC Educational Resources Information Center

Armstrong, Neil

2017-01-01

Peak oxygen uptake (VO[subscript 2]) is internationally recognized as the criterion measure of youth aerobic fitness, but despite pediatric data being available for almost 80 years, its measurement and interpretation in relation to growth, maturation, and health remain controversial. The trainability of youth aerobic fitness continues to be hotly…

Effects of Aerobic Growth on the Fatty Acid and Hydrocarbon Compositions of Geobacter bemidjiensis BemT.

PubMed

Ueno, Akio; Shimizu, Satoru; Hashimoto, Mikako; Adachi, Takumi; Matsushita, Takako; Okuyama, Hidetoshi; Yoshida, Kiyohito

2017-01-01

Geobacter spp., regarded as strict anaerobes, have been reported to grow under aerobic conditions. To elucidate the role of fatty acids in aerobiosis of Geobacter spp., we studied the effect of aerobiosis on fatty acid composition and turnover in G. bemidjiensis Bem T . G. bemidjiensis Bem T was grown under the following different culture conditions: anaerobic culture for 4 days (type 1) and type 1 culture followed by 2-day anaerobic (type 2) or aerobic culture (anaerobic-to-aerobic shift; type 3). The mean cell weight of the type 3 culture was approximately 2.5-fold greater than that of type 1 and 2 cultures. The fatty acid methyl ester and hydrocarbon fraction contained hexadecanoic (16:0), 9-cis-hexadecenoic [16:1(9c)], tetradecanoic (14:0), tetradecenoic [14:1(7c)] acids, hentriacontanonaene, and hopanoids, but not long-chain polyunsaturated fatty acids. The type 3 culture contained higher levels of 14:0 and 14:1(7c) and lower levels of 16:0 and 16:1(9c) compared with type 1 and 2 cultures. The weight ratio of extracted lipid per dry cell was lower in the type 3 culture than in the type 1 and 2 cultures. We concluded that anaerobically-grown G. bemidjiensis Bem T followed by aerobiosis were enhanced in growth, fatty acid turnover, and de novo fatty acid synthesis.

Large-size TlBr single crystal growth and defect study

NASA Astrophysics Data System (ADS)

Zhang, Mingzhi; Zheng, Zhiping; Chen, Zheng; Zhang, Sen; Luo, Wei; Fu, Qiuyun

2018-04-01

Thallium bromide (TlBr) is an attractive semiconductor material for fabrication of radiation detectors due to its high photon stopping power originating from its high atomic number, wide band gap and high resistivity. In this paper the vertical Bridgman method was used for crystal growth and TlBr single crystals with diameter of 15 mm were grown. X-ray diffraction (XRD) was used to identify phase and orientation. Electron backscatter diffraction (EBSD) was used to investigate crystal microstructure and crystallographic orientation. The optical and electric performance of the crystal was characterized by infrared (IR) transmittance spectra and I-V measurement. The types of point defects in the crystals were investigated by thermally stimulated current (TSC) spectra and positron annihilation spectroscopy (PAS). Four types of defects, with ionization energy of each defect fitting as follows: 0.1308, 0.1540, 0.3822 and 0.538 eV, were confirmed from the TSC result. The PAS result showed that there were Tl vacancies in the crystal.

Growth of defect-free GaAsSbN axial nanowires via self-catalyzed molecular beam epitaxy

NASA Astrophysics Data System (ADS)

Sharma, Manish; Deshmukh, Prithviraj; Kasanaboina, Pavan; Reynolds, C. Lewis, Jr.; Liu, Yang; Iyer, Shanthi

2017-12-01

Bandgap reduction of 10% by incorporation of a dilute amount of N is reported for the first time, in axial GaAsSb nanowires (NWs) grown on Si (111) via Ga-assisted molecular beam epitaxy. Impact of N incorporation on the surface morphology, NW growth kinetics, and their structural and optical properties were examined. Dilute nitride NWs with Sb composition of 7 at% did not exhibit any noticeable planar defects, as revealed by the absence of satellite twin peaks in the selected-area diffraction pattern and high-resolution transmission electron microscopy imaging. Point defects were also minimal in as-grown dilute nitride NWs, as ascertained from the comparison of low-temperature photoluminescence spectra as well as the shape and shift of Raman modes, with in situ annealed NWs in different ambients. Evidence of enhanced incorporation of N was found in the NWs in situ annealed in N ambient, but with deteriorated optical quality due to simultaneous creation of N-induced defects. The lack of any noticeable defects in the as-grown GaAsSbN NWs demonstrates the advantage of the vapor-liquid-solid mechanism responsible for growth of axial configuration over the vapor-solid growth mechanism for core-shell NWs as well as their thin film counterpart, which commonly exhibit N-induced point defects.

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

2016-03-09

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.

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.

Reduced Heme Levels Underlie the Exponential Growth Defect of the Shewanella oneidensis hfq Mutant

PubMed Central

Mezoian, Taylor; Hunt, Taylor M.; Keane, Meaghan L.; Leonard, Jessica N.; Scola, Shelby E.; Beer, Emma N.; Perdue, Sarah; Pellock, Brett J.

2014-01-01

The RNA chaperone Hfq fulfills important roles in small regulatory RNA (sRNA) function in many bacteria. Loss of Hfq in the dissimilatory metal reducing bacterium Shewanella oneidensis strain MR-1 results in slow exponential phase growth and a reduced terminal cell density at stationary phase. We have found that the exponential phase growth defect of the hfq mutant in LB is the result of reduced heme levels. Both heme levels and exponential phase growth of the hfq mutant can be completely restored by supplementing LB medium with 5-aminolevulinic acid (5-ALA), the first committed intermediate synthesized during heme synthesis. Increasing expression of gtrA, which encodes the enzyme that catalyzes the first step in heme biosynthesis, also restores heme levels and exponential phase growth of the hfq mutant. Taken together, our data indicate that reduced heme levels are responsible for the exponential growth defect of the S. oneidensis hfq mutant in LB medium and suggest that the S. oneidensis hfq mutant is deficient in heme production at the 5-ALA synthesis step. PMID:25356668

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

Triangular defects in the low-temperature halo-carbon homoepitaxial growth of 4H-SiC

NASA Astrophysics Data System (ADS)

Das, Hrishikesh; Melnychuk, Galyna; Koshka, Yaroslav

2010-06-01

Generation of triangular defects (TDs) is a significant obstacle in the way of increasing the growth rate of the low-temperature halo-carbon homoepitaxial growth of 4H-SiC conducted at 1300 °C. In this work, the structure of the TDs and the factors influencing TD generation were investigated. It has been found that TD concentration at 1300 °C is primarily influenced by the growth rate. Higher concentrations of the TDs were typically observed at the upstream regions of the sample. With the help of KOH defect delineation technique it was established that the locations of the TDs did not coincide with any of the substrate defects. Nucleation of small polycrystalline Si islands is the main origin for the TDs nucleation during the low-temperature growth, especially at moderate-to-low values of the C/Si ratio, which have been previously shown to be favorable for avoiding generation of 3C inclusions and morphology degradation. At typical low-temperature growth conditions, small polycrystalline Si islands can form on SiC surface (predominantly at the upstream portion of the growth zone). Those islands serve as nucleation centers for TDs and subsequently get evaporated. TDs are bound by two or often multiple partial dislocations, which results in one or multiple stacking faults, respectively. When arrays of partial dislocations were present at each edge of a TD, 3C polytype inclusions were often revealed by the oxidation technique and micro-Raman spectroscopy.

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

A novel process-based model of microbial growth: self-inhibition in Saccharomyces cerevisiae aerobic fed-batch cultures.

PubMed

Mazzoleni, Stefano; Landi, Carmine; Cartenì, Fabrizio; de Alteriis, Elisabetta; Giannino, Francesco; Paciello, Lucia; Parascandola, Palma

2015-07-30

Microbial population dynamics in bioreactors depend on both nutrients availability and changes in the growth environment. Research is still ongoing on the optimization of bioreactor yields focusing on the increase of the maximum achievable cell density. A new process-based model is proposed to describe the aerobic growth of Saccharomyces cerevisiae cultured on glucose as carbon and energy source. The model considers the main metabolic routes of glucose assimilation (fermentation to ethanol and respiration) and the occurrence of inhibition due to the accumulation of both ethanol and other self-produced toxic compounds in the medium. Model simulations reproduced data from classic and new experiments of yeast growth in batch and fed-batch cultures. Model and experimental results showed that the growth decline observed in prolonged fed-batch cultures had to be ascribed to self-produced inhibitory compounds other than ethanol. The presented results clarify the dynamics of microbial growth under different feeding conditions and highlight the relevance of the negative feedback by self-produced inhibitory compounds on the maximum cell densities achieved in a bioreactor.

Epithelial Coculture and l-Lactate Promote Growth of Helicobacter cinaedi under H2-Free Aerobic Conditions

PubMed Central

Taniguchi, Takako; Misawa, Naoaki

2016-01-01

ABSTRACT Helicobacter cinaedi is an emerging opportunistic pathogen associated with infections of diverse anatomic sites. Nevertheless, the species demonstrates fastidious axenic growth; it has been described as requiring a microaerobic atmosphere, along with a strong preference for supplemental H2 gas. In this context, we examined the hypothesis that in vitro growth of H. cinaedi could be enhanced by coculture with human epithelial cells. When inoculated (in Ham's F12 medium) over Caco-2 monolayers, the type strain (ATCC BAA-847) gained the ability to proliferate under H2-free aerobic conditions. Identical results were observed during coculture with several other monolayer types (LS-174T, AGS, and HeLa). Under chemically defined conditions, 40 amino acids and carboxylates were screened for their effect on the organism's atmospheric requirements. Several molecules promoted H2-free aerobic proliferation, although it occurred most prominently with millimolar concentrations of l-lactate. The growth response of H. cinaedi to Caco-2 cells and l-lactate was confirmed with a collection of 12 human-derived clinical strains. mRNA sequencing was next performed on the type strain under various growth conditions. In addition to providing a whole-transcriptome profile of H. cinaedi, this analysis demonstrated strong constitutive expression of the l-lactate utilization locus, as well as differential transcription of terminal respiratory proteins as a function of Caco-2 coculture and l-lactate supplementation. Overall, these findings challenge traditional views of H. cinaedi as an obligate microaerophile. IMPORTANCE H. cinaedi is an increasingly recognized pathogen in people with compromised immune systems. Atypical among other members of its bacterial class, H. cinaedi has been associated with infections of diverse anatomic sites. Growing H. cineadi in the laboratory is quite difficult, due in large part to the need for a specialized atmosphere. The suboptimal growth of H

Influence of growth temperature on bulk and surface defects in hybrid lead halide perovskite films

NASA Astrophysics Data System (ADS)

Peng, Weina; Anand, Benoy; Liu, Lihong; Sampat, Siddharth; Bearden, Brandon E.; Malko, Anton V.; Chabal, Yves J.

2016-01-01

The rapid development of perovskite solar cells has focused its attention on defects in perovskites, which are gradually realized to strongly control the device performance. A fundamental understanding is therefore needed for further improvement in this field. Recent efforts have mainly focused on minimizing the surface defects and grain boundaries in thin films. Using time-resolved photoluminescence spectroscopy, we show that bulk defects in perovskite samples prepared using vapor assisted solution process (VASP) play a key role in addition to surface and grain boundary defects. The defect state density of samples prepared at 150 °C (~1017 cm-3) increases by 5 fold at 175 °C even though the average grains size increases slightly, ruling out grain boundary defects as the main mechanism for the observed differences in PL properties upon annealing. Upon surface passivation using water molecules, the PL intensity and lifetime of samples prepared at 200 °C are only partially improved, remaining significantly lower than those prepared at 150 °C. Thus, the present study indicates that the majority of these defect states observed at elevated growth temperatures originates from bulk defects and underscores the importance to control the formation of bulk defects together with grain boundary and surface defects to further improve the optoelectronic properties of perovskites.The rapid development of perovskite solar cells has focused its attention on defects in perovskites, which are gradually realized to strongly control the device performance. A fundamental understanding is therefore needed for further improvement in this field. Recent efforts have mainly focused on minimizing the surface defects and grain boundaries in thin films. Using time-resolved photoluminescence spectroscopy, we show that bulk defects in perovskite samples prepared using vapor assisted solution process (VASP) play a key role in addition to surface and grain boundary defects. The defect state

The Impact of Aerobic Exercise on the Muscle Stem Cell Response.

PubMed

Joanisse, Sophie; Snijders, Tim; Nederveen, Joshua P; Parise, Gianni

2018-04-16

Satellite cells are indispensable for skeletal muscle repair and regeneration and are associated with muscle growth in humans. Aerobic exercise training results in improved skeletal muscle health also translating to an increase in satellite cell pool activation. We postulate that aerobic exercise improves satellite cell function in skeletal muscle.

Investigation on growth and macro-defects of Er3+-doped BaY2F8 laser crystal

NASA Astrophysics Data System (ADS)

Wang, Shuai; Ruan, Yongfeng; Tsuboi, Taiju; Zhang, Shouchao; Wang, Youfa; Tong, Hongshuang

2013-08-01

Large BaY2F8 and Er3+-doped BaY2F8 single crystals were grown by the temperature gradient method. Three kinds of macro-defects were found in BaY2F8 single crystals. These macro-defects include cracks, growth striations and straight pipes. The morphologies and distribution regularities of these macro-defects were observed and studied using a solid polarization microscope. The formation mechanisms and the methods of eliminating these defects were discussed.

Social complementation and growth advantages promote socially defective bacterial isolates.

PubMed

Kraemer, Susanne A; Velicer, Gregory J

2014-04-22

Social interactions among diverse individuals that encounter one another in nature have often been studied among animals but rarely among microbes. For example, the evolutionary forces that determine natural frequencies of bacteria that express cooperative behaviours at low levels remain poorly understood. Natural isolates of the soil bacterium Myxococcus xanthus sampled from the same fruiting body often vary in social phenotypes, such as group swarming and multicellular development. Here, we tested whether genotypes highly proficient at swarming or development might promote the persistence of less socially proficient genotypes from the same fruiting body. Fast-swarming strains complemented slower isolates, allowing the latter to keep pace with faster strains in mixed groups. During development, one low-sporulating strain was antagonized by high sporulators, whereas others with severe developmental defects had those defects partially complemented by high-sporulating strains. Despite declining in frequency overall during competition experiments spanning multiple cycles of development, developmentally defective strains exhibited advantages during the growth phases of competitions. These results suggest that microbes with low-sociality phenotypes often benefit from interacting with more socially proficient strains. Such complementation may combine with advantages at other traits to increase equilibrium frequencies of low-sociality genotypes in natural populations.

Nitrogen and silicon defect incorporation during homoepitaxial CVD diamond growth on (111) surfaces

DOE PAGES

Moore, Samuel L.; Vohra, Yogesh K.

2015-01-01

Chemical Vapor Deposited (CVD) diamond growth on (111)-diamond surfaces has received increased attention lately because of the use of N-V related centers in quantum computing as well as application of these defect centers in sensing nano-Tesla strength magnetic fields. We have carried out a detailed study of homoepitaxial diamond deposition on (111)-single crystal diamond (SCD) surfaces using a 1.2 kW microwave plasma CVD (MPCVD) system employing methane/hydrogen/nitrogen/oxygen gas phase chemistry. We have utilized Type Ib (111)-oriented single crystal diamonds as seed crystals in our study. The homoepitaxially grown diamond films were analyzed by Raman spectroscopy, Photoluminescence Spectroscopy (PL), X-ray Photoelectronmore » Spectroscopy (XPS), Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). The nitrogen concentration in the plasma was carefully varied between 0 and 1500 ppm while a ppm level of silicon impurity is present in the plasma from the quartz bell jar. The concentration of N-V defect centers with PL zero phonon lines (ZPL) at 575nm and 637nm and the Si-defect center with a ZPL at 737nm were experimentally detected from a variation in CVD growth conditions and were quantitatively studied. As a result, altering nitrogen and oxygen concentration in the plasma was observed to directly affect N-V and Si-defect incorporation into the (111)-oriented diamond lattice and these findings are presented.« less

Modelling of thermal field and point defect dynamics during silicon single crystal growth using CZ technique

NASA Astrophysics Data System (ADS)

Sabanskis, A.; Virbulis, J.

2018-05-01

Mathematical modelling is employed to numerically analyse the dynamics of the Czochralski (CZ) silicon single crystal growth. The model is axisymmetric, its thermal part describes heat transfer by conduction and thermal radiation, and allows to predict the time-dependent shape of the crystal-melt interface. Besides the thermal field, the point defect dynamics is modelled using the finite element method. The considered process consists of cone growth and cylindrical phases, including a short period of a reduced crystal pull rate, and a power jump to avoid large diameter changes. The influence of the thermal stresses on the point defects is also investigated.

Aerobic microbial enhanced oil recovery

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 takemore » place. Maximum efficiency was reached at low oxygen concentrations, approximately 1 mg O{sub 2}/liter.« less

Influence of growth temperature on bulk and surface defects in hybrid lead halide perovskite films.

PubMed

Peng, Weina; Anand, Benoy; Liu, Lihong; Sampat, Siddharth; Bearden, Brandon E; Malko, Anton V; Chabal, Yves J

2016-01-21

The rapid development of perovskite solar cells has focused its attention on defects in perovskites, which are gradually realized to strongly control the device performance. A fundamental understanding is therefore needed for further improvement in this field. Recent efforts have mainly focused on minimizing the surface defects and grain boundaries in thin films. Using time-resolved photoluminescence spectroscopy, we show that bulk defects in perovskite samples prepared using vapor assisted solution process (VASP) play a key role in addition to surface and grain boundary defects. The defect state density of samples prepared at 150 °C (∼10(17) cm(-3)) increases by 5 fold at 175 °C even though the average grains size increases slightly, ruling out grain boundary defects as the main mechanism for the observed differences in PL properties upon annealing. Upon surface passivation using water molecules, the PL intensity and lifetime of samples prepared at 200 °C are only partially improved, remaining significantly lower than those prepared at 150 °C. Thus, the present study indicates that the majority of these defect states observed at elevated growth temperatures originates from bulk defects and underscores the importance to control the formation of bulk defects together with grain boundary and surface defects to further improve the optoelectronic properties of perovskites.

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.

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

Molecular dynamics studies of defect formation during heteroepitaxial growth of InGaN alloys on (0001) GaN surfaces

NASA Astrophysics Data System (ADS)

Gruber, J.; Zhou, X. W.; Jones, R. E.; Lee, S. R.; Tucker, G. J.

2017-05-01

We investigate the formation of extended defects during molecular-dynamics (MD) simulations of GaN and InGaN growth on (0001) and ( 11 2 ¯ 0 ) wurtzite-GaN surfaces. The simulated growths are conducted on an atypically large scale by sequentially injecting nearly a million individual vapor-phase atoms towards a fixed GaN surface; we apply time-and-position-dependent boundary constraints that vary the ensemble treatments of the vapor-phase, the near-surface solid-phase, and the bulk-like regions of the growing layer. The simulations employ newly optimized Stillinger-Weber In-Ga-N-system potentials, wherein multiple binary and ternary structures are included in the underlying density-functional-theory training sets, allowing improved treatment of In-Ga-related atomic interactions. To examine the effect of growth conditions, we study a matrix of >30 different MD-growth simulations for a range of InxGa1-xN-alloy compositions (0 ≤ x ≤ 0.4) and homologous growth temperatures [0.50 ≤ T/T*m(x) ≤ 0.90], where T*m(x) is the simulated melting point. Growths conducted on polar (0001) GaN substrates exhibit the formation of various extended defects including stacking faults/polymorphism, associated domain boundaries, surface roughness, dislocations, and voids. In contrast, selected growths conducted on semi-polar ( 11 2 ¯ 0 ) GaN, where the wurtzite-phase stacking sequence is revealed at the surface, exhibit the formation of far fewer stacking faults. We discuss variations in the defect formation with the MD growth conditions, and we compare the resulting simulated films to existing experimental observations in InGaN/GaN. While the palette of defects observed by MD closely resembles those observed in the past experiments, further work is needed to achieve truly predictive large-scale simulations of InGaN/GaN crystal growth using MD methodologies.

Adolescent Trajectories of Aerobic Fitness and Adiposity as Markers of Cardiometabolic Risk in Adulthood.

PubMed

Jackowski, S A; Eisenmann, J C; Sherar, L B; Bailey, D A; Baxter-Jones, A D G

2017-01-01

The aim of this study was to investigate whether adolescent growth trajectories of aerobic fitness and adiposity were associated with mid-adulthood cardiometabolic risk (CMR). Participants were drawn from the Saskatchewan Growth and Development Study (1963-1973). Adolescent growth trajectories for maximal aerobic capacity (absolute VO 2 (AbsVO 2 )), skinfolds (SF), representing total body (Sum6SF) and central adiposity (TrunkSF), and body mass index (BMI) were determined from 7 to 17 years of age. In mid-adulthood (40 to 50 years of age), 61 individuals (23 females) returned for follow-ups. A CMR score was calculated to group participants as displaying either high or a low CMR. Multilevel hierarchical models were constructed, comparing the adolescent growth trajectories of AbsVO 2, Sum6SF, TrunkSF, and BMI between CMR groupings. There were no significant differences in the adolescent development of AbsVO 2, Sum6SF, TrunkSF, and BMI between adult CMR groupings ( p > 0.05). Individuals with high CMR accrued 62% greater adjusted total body fat percentage from adolescence to adulthood ( p =0.03). Growth trajectories of adolescent aerobic fitness and adiposity do not appear to be associated with mid-adulthood CMR. Individuals should be encouraged to participate in behaviours that promote healthy aerobic fitness and adiposity levels throughout life to reduce lifelong CMR.

Adolescent Trajectories of Aerobic Fitness and Adiposity as Markers of Cardiometabolic Risk in Adulthood

PubMed Central

Eisenmann, J. C.; Sherar, L. B.; Bailey, D. A.; Baxter-Jones, A. D. G.

2017-01-01

Purpose The aim of this study was to investigate whether adolescent growth trajectories of aerobic fitness and adiposity were associated with mid-adulthood cardiometabolic risk (CMR). Methods Participants were drawn from the Saskatchewan Growth and Development Study (1963–1973). Adolescent growth trajectories for maximal aerobic capacity (absolute VO2 (AbsVO2)), skinfolds (SF), representing total body (Sum6SF) and central adiposity (TrunkSF), and body mass index (BMI) were determined from 7 to 17 years of age. In mid-adulthood (40 to 50 years of age), 61 individuals (23 females) returned for follow-ups. A CMR score was calculated to group participants as displaying either high or a low CMR. Multilevel hierarchical models were constructed, comparing the adolescent growth trajectories of AbsVO2, Sum6SF, TrunkSF, and BMI between CMR groupings. Results There were no significant differences in the adolescent development of AbsVO2, Sum6SF, TrunkSF, and BMI between adult CMR groupings (p > 0.05). Individuals with high CMR accrued 62% greater adjusted total body fat percentage from adolescence to adulthood (p=0.03). Conclusions Growth trajectories of adolescent aerobic fitness and adiposity do not appear to be associated with mid-adulthood CMR. Individuals should be encouraged to participate in behaviours that promote healthy aerobic fitness and adiposity levels throughout life to reduce lifelong CMR. PMID:29279776

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. Published by Elsevier Ltd.

Tailoring the strain in Si nano-structures for defect-free epitaxial Ge over growth.

PubMed

Zaumseil, P; Yamamoto, Y; Schubert, M A; Capellini, G; Skibitzki, O; Zoellner, M H; Schroeder, T

2015-09-04

We investigate the structural properties and strain state of Ge nano-structures selectively grown on Si pillars of about 60 nm diameter with different SiGe buffer layers. A matrix of TEOS SiO2 surrounding the Si nano-pillars causes a tensile strain in the top part at the growth temperature of the buffer that reduces the misfit and supports defect-free initial growth. Elastic relaxation plays the dominant role in the further increase of the buffer thickness and subsequent Ge deposition. This method leads to Ge nanostructures on Si that are free from misfit dislocations and other structural defects, which is not the case for direct Ge deposition on these pillar structures. The Ge content of the SiGe buffer is thereby not a critical parameter; it may vary over a relatively wide range.

Study of Te Inclusion and Related Point Defects in THM-Growth CdMnTe Crystal

NASA Astrophysics Data System (ADS)

Mao, Yifei; Zhang, Jijun; Min, Jiahua; Liang, Xiaoyan; Huang, Jian; Tang, Ke; Ling, Liwen; Li, Ming; Zhang, Ying; Wang, Linjun

2018-02-01

This study establishes a model for describing the interaction between Te inclusions, dislocations and point defects in CdMnTe crystals. The role of the complex environment surrounding the formation of Te inclusions was analyzed. Images of Te inclusions captured by scanning electron microscope and infrared microscope were used to observe the morphology of Te inclusions. The morphology of Te inclusions is discussed in light of crystallography, from the crystal growth temperature at 900°C to the melting temperature of Te inclusions using the traveling heater method. The dislocation nets around Te inclusions were calculated by counting lattice mismatches between the Te inclusions and the bulk CdMnTe at 470°C. The point defects of Te antisites were found to be gathered around Te inclusions, with dislocation climb during the cooling phase of crystal growth from 470°C to room temperature. The Te inclusions, dislocation nets and surrounding point defects are considered to be an entirety for evaluating the effect of Te inclusions on CdMnTe detector performance, and an effective mobility-lifetime product (μτ) was obtained.

Aerobic Growth of Rhodococcus aetherivorans BCP1 Using Selected Naphthenic Acids as the Sole Carbon and Energy Sources

PubMed Central

Presentato, Alessandro; Cappelletti, Martina; Sansone, Anna; Ferreri, Carla; Piacenza, Elena; Demeter, Marc A.; Crognale, Silvia; Petruccioli, Maurizio; Milazzo, Giorgio; Fedi, Stefano; Steinbüchel, Alexander; Turner, Raymond J.; Zannoni, Davide

2018-01-01

Naphthenic acids (NAs) are an important group of toxic organic compounds naturally occurring in hydrocarbon deposits. This work shows that Rhodococcus aetherivorans BCP1 cells not only utilize a mixture of eight different NAs (8XNAs) for growth but they are also capable of marked degradation of two model NAs, cyclohexanecarboxylic acid (CHCA) and cyclopentanecarboxylic acid (CPCA) when supplied at concentrations from 50 to 500 mgL-1. The growth curves of BCP1 on 8XNAs, CHCA, and CPCA showed an initial lag phase not present in growth on glucose, which presumably was related to the toxic effects of NAs on the cell membrane permeability. BCP1 cell adaptation responses that allowed survival on NAs included changes in cell morphology, production of intracellular bodies and changes in fatty acid composition. Transmission electron microscopy (TEM) analysis of BCP1 cells grown on CHCA or CPCA showed a slight reduction in the cell size, the production of EPS-like material and intracellular electron-transparent and electron-dense inclusion bodies. The electron-transparent inclusions increased in the amount and size in NA-grown BCP1 cells under nitrogen limiting conditions and contained storage lipids as suggested by cell staining with the lipophilic Nile Blue A dye. Lipidomic analyses revealed significant changes with increases of methyl-branched (MBFA) and polyunsaturated fatty acids (PUFA) examining the fatty acid composition of NAs-growing BCP1 cells. PUFA biosynthesis is not usual in bacteria and, together with MBFA, can influence structural and functional processes with resulting effects on cell vitality. Finally, through the use of RT (Reverse Transcription)-qPCR, a gene cluster (chcpca) was found to be transcriptionally induced during the growth on CHCA and CPCA. Based on the expression and bioinformatics results, the predicted products of the chcpca gene cluster are proposed to be involved in aerobic NA degradation in R. aetherivorans BCP1. This study provides first

Aerobic metabolism in the genus Lactobacillus: impact on stress response and potential applications in the food industry.

PubMed

Zotta, T; Parente, E; Ricciardi, A

2017-04-01

This review outlines the recent advances in the knowledge on aerobic and respiratory growth of lactic acid bacteria, focusing on the features of respiration-competent lactobacilli. The species of the genus Lactobacillus have been traditionally classified as oxygen-tolerant anaerobes, but it has been demonstrated that several strains are able to use oxygen as a substrate in reactions mediated by flavin oxidases and, in some cases, to synthesize a minimal respiratory chain. The occurrence of genes related to aerobic and respiratory metabolism and to oxidative stress response apparently correlates with the taxonomic position of lactobacilli. Members of the ecologically versatile Lactobacillus casei, L. plantarum and L. sakei groups are apparently best equipped to deal with aerobic/respiratory growth. The shift from anaerobic growth to aerobic (oxygen) and/or respiratory promoting (oxygen, exogenous haem and menaquinone) conditions offers physiological advantages and affects the pattern of metabolite production in several species. Even if this does not result in dramatic increases in biomass production and growth rate, cells grown in these conditions have improved tolerance to heat and oxidative stresses. An overview of benefits and of the potential applications of Lactobacillus cultures grown under aerobic or respiratory conditions is also discussed. © 2017 The Society for Applied Microbiology.

Transforming growth factor-beta1 accelerates resorption of a calcium carbonate biomaterial in periodontal defects.

PubMed

Koo, Ki-Tae; Susin, Cristiano; Wikesjö, Ulf M E; Choi, Seong-Ho; Kim, Chong-Kwan

2007-04-01

In a previous study, recombinant human transforming growth factor-beta1 (rhTGF-beta(1)) in a calcium carbonate carrier was implanted into critical-size, supraalveolar periodontal defects under conditions for guided tissue regeneration (GTR) to study whether rhTGF-beta(1) would enhance or accelerate periodontal regeneration. The results showed minimal benefits of rhTGF-beta(1), and a clear account for this could not be offered. One potential cause may be that the rhTGF-beta(1) formulation was biologically inactive. Several growth or differentiation factors have been suggested to accelerate degradation of biomaterials used as carriers. The objective of this study was to evaluate possible activity of rhTGF-beta(1) on biodegradation of the calcium carbonate carrier. rhTGF-beta(1) in a putty-formulated particulate calcium carbonate carrier was implanted into critical-size, supraalveolar periodontal defects under conditions for GTR in five beagle dogs. Contralateral defects received the calcium carbonate carrier combined with GTR without rhTGF-beta(1) (control). The animals were euthanized at week 4 post-surgery and block biopsies of the defect sites were collected for histologic and histometric analysis. Radiographs were obtained at defect creation and weeks 2 and 4 after defect creation. No statistically significant differences were observed in new bone formation (bone height and area) among the treatments. However, total residual carrier was significantly reduced in sites receiving rhTGF-beta(1) compared to control (P = 0.04). Similarly, carrier density was considerably reduced in sites receiving rhTGF-beta(1) compared to control; the difference was borderline statistically significant (P = 0.06). Within the limitations of the study, it may be concluded that rhTGF-beta(1) accelerates biodegradation of a particulate calcium carbonate biomaterial, indicating a biologic activity of the rhTGF-beta(1) formulation apparently not encompassing enhanced or accelerated

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.

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. Copyright © 2014 Elsevier Ltd. All rights reserved.

Molecular dynamics studies of defect formation during heteroepitaxial growth of InGaN alloys on (0001) GaN surfaces

DOE PAGES

Gruber, J.; Zhou, X. W.; Jones, R. E.; ...

2017-05-15

Here, we investigate the formation of extended defects during molecular-dynamics (MD) simulations of GaN and InGaN growth on (0001) and (11more » $$\\bar{2}$$0) wurtzite-GaN surfaces. The simulated growths are conducted on an atypically large scale by sequentially injecting nearly a million individual vapor-phase atoms towards a fixed GaN surface; we apply time-and-position-dependent boundary constraints that vary the ensemble treatments of the vapor-phase, the near-surface solid-phase, and the bulk-like regions of the growing layer. The simulations employ newly optimized Stillinger-Weber In-Ga-N-system potentials, wherein multiple binary and ternary structures are included in the underlying density-functional-theory training sets, allowing improved treatment of In-Ga-related atomic interactions. To examine the effect of growth conditions, we study a matrix of >30 different MD-growth simulations for a range of InxGa1-xN-alloy compositions (0 ≤ x ≤ 0.4) and homologous growth temperatures [0.50 ≤ T/T* m(x) ≤ 0.90], where T* m(x) is the simulated melting point. Growths conducted on polar (0001) GaN substrates exhibit the formation of various extended defects including stacking faults/polymorphism, associated domain boundaries, surface roughness, dislocations, and voids. In contrast, selected growths conducted on semi-polar (11$$\\bar{2}$$0) GaN, where the wurtzite-phase stacking sequence is revealed at the surface, exhibit the formation of far fewer stacking faults. We discuss variations in the defect formation with the MD growth conditions, and we compare the resulting simulated films to existing experimental observations in InGaN/GaN. Finally, while the palette of defects observed by MD closely resembles those observed in the past experiments, further work is needed to achieve truly predictive large-scale simulations of InGaN/GaN crystal growth using MD methodologies.« less

Molecular dynamics studies of defect formation during heteroepitaxial growth of InGaN alloys on (0001) GaN surfaces.

PubMed

Gruber, J; Zhou, X W; Jones, R E; Lee, S R; Tucker, G J

2017-05-21

We investigate the formation of extended defects during molecular-dynamics (MD) simulations of GaN and InGaN growth on (0001) and ([Formula: see text]) wurtzite-GaN surfaces. The simulated growths are conducted on an atypically large scale by sequentially injecting nearly a million individual vapor-phase atoms towards a fixed GaN surface; we apply time-and-position-dependent boundary constraints that vary the ensemble treatments of the vapor-phase, the near-surface solid-phase, and the bulk-like regions of the growing layer. The simulations employ newly optimized Stillinger-Weber In-Ga-N-system potentials, wherein multiple binary and ternary structures are included in the underlying density-functional-theory training sets, allowing improved treatment of In-Ga-related atomic interactions. To examine the effect of growth conditions, we study a matrix of >30 different MD-growth simulations for a range of In x Ga 1-x N-alloy compositions (0 ≤  x  ≤ 0.4) and homologous growth temperatures [0.50 ≤  T/T * m ( x ) ≤ 0.90], where T * m ( x ) is the simulated melting point. Growths conducted on polar (0001) GaN substrates exhibit the formation of various extended defects including stacking faults/polymorphism, associated domain boundaries, surface roughness, dislocations, and voids. In contrast, selected growths conducted on semi-polar ([Formula: see text]) GaN, where the wurtzite-phase stacking sequence is revealed at the surface, exhibit the formation of far fewer stacking faults. We discuss variations in the defect formation with the MD growth conditions, and we compare the resulting simulated films to existing experimental observations in InGaN/GaN. While the palette of defects observed by MD closely resembles those observed in the past experiments, further work is needed to achieve truly predictive large-scale simulations of InGaN/GaN crystal growth using MD methodologies.

Meckel's and condylar cartilages anomalies in achondroplasia result in defective development and growth of the mandible.

PubMed

Biosse Duplan, Martin; Komla-Ebri, Davide; Heuzé, Yann; Estibals, Valentin; Gaudas, Emilie; Kaci, Nabil; Benoist-Lasselin, Catherine; Zerah, Michel; Kramer, Ina; Kneissel, Michaela; Porta, Diana Grauss; Di Rocco, Federico; Legeai-Mallet, Laurence

2016-07-15

Activating FGFR3 mutations in human result in achondroplasia (ACH), the most frequent form of dwarfism, where cartilages are severely disturbed causing long bones, cranial base and vertebrae defects. Because mandibular development and growth rely on cartilages that guide or directly participate to the ossification process, we investigated the impact of FGFR3 mutations on mandibular shape, size and position. By using CT scan imaging of ACH children and by analyzing Fgfr3 Y367C/+ mice, a model of ACH, we show that FGFR3 gain-of-function mutations lead to structural anomalies of primary (Meckel's) and secondary (condylar) cartilages of the mandible, resulting in mandibular hypoplasia and dysmorphogenesis. These defects are likely related to a defective chondrocyte proliferation and differentiation and pan-FGFR tyrosine kinase inhibitor NVP-BGJ398 corrects Meckel's and condylar cartilages defects ex vivo. Moreover, we show that low dose of NVP-BGJ398 improves in vivo condyle growth and corrects dysmorphologies in Fgfr3 Y367C/+ mice, suggesting that postnatal treatment with NVP-BGJ398 mice might offer a new therapeutic strategy to improve mandible anomalies in ACH and others FGFR3-related disorders. © The Author 2016. Published by Oxford University Press.

Aberrant temporal growth pattern and morphology of root and shoot caused by a defective circadian clock in Arabidopsis thaliana.

PubMed

Ruts, Tom; Matsubara, Shizue; Wiese-Klinkenberg, Anika; Walter, Achim

2012-10-01

Circadian clocks synchronized with the environment allow plants to anticipate recurring daily changes and give a fitness advantage. Here, we mapped the dynamic growth phenotype of leaves and roots in two lines of Arabidopsis thaliana with a disrupted circadian clock: the CCA1 over-expressing line (CCA1ox) and the prr9 prr7 prr5 (prr975) mutant. We demonstrate leaf growth defects due to a disrupted circadian clock over a 24 h time scale. Both lines showed enhanced leaf growth compared with the wild-type during the diurnal period, suggesting increased partitioning of photosynthates for leaf growth. Nocturnal leaf growth was reduced and growth inhibition occurred by dawn, which may be explained by ineffective starch degradation in the leaves of the mutants. However, this growth inhibition was not caused by starch exhaustion. Overall, these results are consistent with the notion that the defective clock affects carbon and energy allocation, thereby reducing growth capacity during the night. Furthermore, rosette morphology and size as well as root architecture were strikingly altered by the defective clock control. Separate analysis of the primary root and lateral roots revealed strong suppression of lateral root formation in both CCA1ox and prr975, accompanied by unusual changes in lateral root growth direction under light-dark cycles and increased lateral extension of the root system. We conclude that growth of the whole plant is severely affected by improper clock regulation in A. thaliana, resulting not only in altered timing and capacity for growth but also aberrant development of shoot and root architecture. © 2012 Forschungszentrum Jülich. The Plant Journal © 2012 Blackwell Publishing Ltd.

Effects of Aerobic Exercise on Mild Cognitive Impairment

PubMed Central

Baker, Laura D.; Frank, Laura L.; Foster-Schubert, Karen; Green, Pattie S.; Wilkinson, Charles W.; McTiernan, Anne; Plymate, Stephen R.; Fishel, Mark A.; Stennis Watson, G.; Cholerton, Brenna A.; Duncan, Glen E.; Mehta, Pankaj D.; Craft, Suzanne

2011-01-01

Objectives To examine the effects of aerobic exercise on cognition and other biomarkers associated with Alzheimer disease pathology for older adults with mild cognitive impairment, and assess the role of sex as a predictor of response. Design Six-month, randomized, controlled, clinical trial. Setting Veterans Affairs Puget Sound Health Care System clinical research unit. Participants Thirty-three adults (17 women) with amnestic mild cognitive impairment ranging in age from 55 to 85 years (mean age,70 years). Intervention Participants were randomized either to a high-intensity aerobic exercise or stretching control group. The aerobic group exercised under the supervision of a fitness trainer at 75% to 85% of heart rate reserve for 45 to 60 min/d, 4 d/wk for 6 months. The control group carried out supervised stretching activities according to the same schedule but maintained their heart rate at or below 50% of their heart rate reserve. Before and after the study, glucometabolic and treadmill tests were performed and fat distribution was assessed using dual-energy x-ray absorptiometry. At baseline, month 3, and month 6, blood was collected for assay and cognitive tests were administered. Main Outcome Measures Performance measures on Symbol-Digit Modalities, Verbal Fluency, Stroop, Trails B, Task Switching, Story Recall, and List Learning. Fasting plasma levels of insulin, cortisol, brain-derived neurotrophic factor, insulinlike growth factor-I, and β-amyloids 40 and 42. Results Six months of high-intensity aerobic exercise had sex-specific effects on cognition, glucose metabolism, and hypothalamic-pituitary-adrenal axis and trophic activity despite comparable gains in cardiorespiratory fitness and body fat reduction. For women, aerobic exercise improved performance on multiple tests of executive function, increased glucose disposal during the metabolic clamp, and reduced fasting plasma levels of insulin, cortisol, and brain-derived neurotrophic factor. For men

Atomic Force Microscope Observation of Growth and Defects on As-Grown (111) 3C-SiC Mesa Surfaces

NASA Technical Reports Server (NTRS)

Neudeck, Philip G.; Trunek, Andrew J.; Powell, J. Anthony

2004-01-01

This paper presents experimental atomic force microscope (AFM) observations of the surface morphology of as-grown (111) silicon-face 3C-SiC mesa heterofilms. Wide variations in 3C surface step structure are observed as a function of film growth conditions and film defect content. The vast majority of as-grown 3C-SiC surfaces consisted of trains of single bilayer height (0.25 nm) steps. Macrostep formation (i.e., step-bunching) was rarely observed, and then only on mesa heterofilms with extended crystal defects. As supersaturation is lowered by decreasing precursor concentration, terrace nucleation on the top (111) surface becomes suppressed, sometimes enabling the formation of thin 3C-SiC film surfaces completely free of steps. For thicker films, propagation of steps inward from mesa edges is sometimes observed, suggesting that enlarging 3C mesa sidewall facets begin to play an increasingly important role in film growth. The AFM observation of stacking faults (SF's) and 0.25 nm Burgers vector screw component growth spirals on the as-grown surface of defective 3C films is reported.

Aerobic scope fails to explain the detrimental effects on growth resulting from warming and elevated CO2 in Atlantic halibut.

PubMed

Gräns, Albin; Jutfelt, Fredrik; Sandblom, Erik; Jönsson, Elisabeth; Wiklander, Kerstin; Seth, Henrik; Olsson, Catharina; Dupont, Sam; Ortega-Martinez, Olga; Einarsdottir, Ingibjörg; Björnsson, Björn Thrandur; Sundell, Kristina; Axelsson, Michael

2014-03-01

As a consequence of increasing atmospheric CO2, the world's oceans are becoming warmer and more acidic. Whilst the ecological effects of these changes are poorly understood, it has been suggested that fish performance including growth will be reduced mainly as a result of limitations in oxygen transport capacity. Contrary to the predictions given by the oxygen- and capacity-limited thermal tolerance hypothesis, we show that aerobic scope and cardiac performance of Atlantic halibut (Hippoglossus hippoglossus) increase following 14-16 weeks exposure to elevated temperatures and even more so in combination with CO2-acidified seawater. However, the increase does not translate into improved growth, demonstrating that oxygen uptake is not the limiting factor for growth performance at high temperatures. Instead, long-term exposure to CO2-acidified seawater reduces growth at temperatures that are frequently encountered by this species in nature, indicating that elevated atmospheric CO2 levels may have serious implications on fish populations in the future.

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

Characterization of an Isolate That Uses Vinyl Chloride as a Growth Substrate under Aerobic Conditions

PubMed Central

Verce, Matthew F.; Ulrich, Ricky L.; Freedman, David L.

2000-01-01

An aerobic enrichment culture was developed by using vinyl chloride (VC) as the sole organic carbon and electron donor source. VC concentrations as high as 7.3 mM were biodegraded without apparent inhibition. VC use did not occur when nitrate was provided as the electron acceptor. A gram-negative, rod-shaped, motile isolate was obtained from the enrichment culture and identified based on biochemical characteristics and the sequence of its 16S rRNA gene as Pseudomonas aeruginosa, designated strain MF1. The observed yield of MF1 when it was grown on VC was 0.20 mg of total suspended solids (TSS)/mg of VC. Ethene, acetate, glyoxylate, and glycolate also served as growth substrates, while ethane, chloroacetate, glycolaldehyde, and phenol did not. Stoichiometric release of chloride and minimal accumulation of soluble metabolites following VC consumption indicated that the predominant fate for VC is mineralization and incorporation into cell material. MF1 resumed consumption of VC after at least 24 days when none was provided, unlike various mycobacteria that lost their VC-degrading ability after brief periods in the absence of VC. When deprived of oxygen for 2.5 days, MF1 did not regain the ability to grow on VC, and a portion of the VC was transformed into VC-epoxide. Acetylene inhibited VC consumption by MF1, suggesting the involvement of a monooxygenase in the initial step of VC metabolism. The maximum specific VC utilization rate for MF1 was 0.41 μmol of VC/mg of TSS/day, the maximum specific growth rate was 0.0048/day, and the Monod half-saturation coefficient was 0.26 μM. A higher yield and faster kinetics occurred when MF1 grew on ethene. When grown on ethene, MF1 was able to switch to VC as a substrate without a lag. It therefore appears feasible to grow MF1 on a nontoxic substrate and then apply it to environments that do not exhibit a capacity for aerobic biodegradation of VC. PMID:10919818

Meckel’s and condylar cartilages anomalies in achondroplasia result in defective development and growth of the mandible

PubMed Central

Biosse Duplan, Martin; Komla-Ebri, Davide; Heuzé, Yann; Estibals, Valentin; Gaudas, Emilie; Kaci, Nabil; Benoist-Lasselin, Catherine; Zerah, Michel; Kramer, Ina; Kneissel, Michaela; Porta, Diana Grauss; Di Rocco, Federico; Legeai-Mallet, Laurence

2016-01-01

Activating FGFR3 mutations in human result in achondroplasia (ACH), the most frequent form of dwarfism, where cartilages are severely disturbed causing long bones, cranial base and vertebrae defects. Because mandibular development and growth rely on cartilages that guide or directly participate to the ossification process, we investigated the impact of FGFR3 mutations on mandibular shape, size and position. By using CT scan imaging of ACH children and by analyzing Fgfr3Y367C/+ mice, a model of ACH, we show that FGFR3 gain-of-function mutations lead to structural anomalies of primary (Meckel’s) and secondary (condylar) cartilages of the mandible, resulting in mandibular hypoplasia and dysmorphogenesis. These defects are likely related to a defective chondrocyte proliferation and differentiation and pan-FGFR tyrosine kinase inhibitor NVP-BGJ398 corrects Meckel’s and condylar cartilages defects ex vivo. Moreover, we show that low dose of NVP-BGJ398 improves in vivo condyle growth and corrects dysmorphologies in Fgfr3Y367C/+ mice, suggesting that postnatal treatment with NVP-BGJ398 mice might offer a new therapeutic strategy to improve mandible anomalies in ACH and others FGFR3-related disorders. PMID:27260401

Nucleation and growth kinetics for intercalated islands during deposition on layered materials with isolated pointlike surface defects

DOE PAGES

Han, Yong; Lii-Rosales, A.; Zhou, Y.; ...

2017-10-13

Theory and stochastic lattice-gas modeling is developed for the formation of intercalated metal islands in the gallery between the top layer and the underlying layer at the surface of layered materials. Our model for this process involves deposition of atoms, some fraction of which then enter the gallery through well-separated pointlike defects in the top layer. Subsequently, these atoms diffuse within the subsurface gallery leading to nucleation and growth of intercalated islands nearby the defect point source. For the case of a single point defect, continuum diffusion equation analysis provides insight into the nucleation kinetics. However, complementary tailored lattice-gas modelingmore » produces a more comprehensive and quantitative characterization. We analyze the large spread in nucleation times and positions relative to the defect for the first nucleated island. We also consider the formation of subsequent islands and the evolution of island growth shapes. The shapes reflect in part our natural adoption of a hexagonal close-packed island structure. As a result, motivation and support for the model is provided by scanning tunneling microscopy observations of the formation of intercalated metal islands in highly-ordered pyrolytic graphite at higher temperatures.« less

Stable Defects in Semiconductor Nanowires.

PubMed

Sanchez, A M; Gott, J A; Fonseka, H A; Zhang, Y; Liu, H; Beanland, R

2018-05-09

Semiconductor nanowires are commonly described as being defect-free due to their ability to expel mobile defects with long-range strain fields. Here, we describe previously undiscovered topologically protected line defects with null Burgers vector that, unlike dislocations, are stable in nanoscale crystals. We analyze the defects present in semiconductor nanowires in regions of imperfect crystal growth, i.e., at the nanowire tip formed during consumption of the droplet in self-catalyzed vapor-liquid-solid growth and subsequent vapor-solid shell growth. We use a form of the Burgers circuit method that can be applied to multiply twinned material without difficulty. Our observations show that the nanowire microstructure is very different from bulk material, with line defects either (a) trapped by locks or other defects, (b) arranged as dipoles or groups with a zero total Burgers vector, or (c) have a zero Burgers vector. We find two new line defects with a null Burgers vector, formed from the combination of partial dislocations in twinned material. The most common defect is the three-monolayer high twin facet with a zero Burgers vector. Studies of individual nanowires using cathodoluminescence show that optical emission is quenched in defective regions, showing that they act as strong nonradiative recombination centers.

Effects of growth hormone and testosterone therapy on aerobic and anaerobic fitness, body composition and lipoprotein profile in middle-aged men.

PubMed

Zając, Adam; Wilk, Michał; Socha, Teresa; Maszczyk, Adam; Chycki, Jakub

2014-01-01

Andropause and aging are associated with neuroendocrine dysfunctions. Growth hormone and testosterone play a significant role in several processes affecting adaptation and thereby also everyday functioning. The aim of this research project was to evaluate the effects of recombinant human growth hormone and testosterone enanthate injections on body mass and body composition, aerobic and anaerobic fitness and lipid profile in middle-aged men. The research group was comprised of 14 men aged 45 - 60 years. Two series of laboratory analyses were performed. Independent tests were carried out at baseline and after 12 weeks of the experiment. The data were analyzed using Statistica 9.1 software. A two-way repeated measures ANOVA revealed a statistically significant effect of the intervention programme on fat-free mass (η(2)=0.34), total body fat (η(2)=0.79), total cholesterol (η(2)=0.30), high-density lipoprotein cholesterol (η(2)=0.31), low-density lipoprotein cholesterol (η(2)=0.42), triglyceride (η(2)=0.28), testosterone (η(2)=0.52), insulin-like growth factor 1 (η(2)=0.47) and growth hormone (η(2)=0.63). Furthermore, ANOVA revealed a statistically significant effect of the rhGH and T treatment on maximal oxygen uptake (η(2)=0.63), anaerobic threshold (η(2)=0.61) and maximal work rate (η(2)=0.53). It should be emphasized that the lipid profile was affected not only by rhGH+T replacement therapy, but also by the prescribed physical activity programme. The strength and endurance fitness programme alone did not cause significant changes in body mass and composition, nor the anaerobic and aerobic capacity. On the other hand, the rhGH=T treatment stimulated these changes significantly.

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.

Transforming Growth Factor-β1 Accelerates Resorption of a Calcium Carbonate Biomaterial in Periodontal Defects.

PubMed

Koo, Ki-Tae; Susin, Cristiano; Wikesjö, Ulf M E; Choi, Seong-Ho; Kim, Chong-Kwan

2007-04-01

In a previous study, recombinant human transforming growth factor-beta1 (rhTGF-β 1 ) in a calcium carbonate carrier was implanted into critical-size, supraalveolar periodontal defects under conditions for guided tissue regeneration (GTR) to study whether rhTGF-β 1 would enhance or accelerate periodontal regeneration. The results showed minimal benefits of rhTGF-β 1 , and a clear account for this could not be offered. One potential cause may be that the rhTGF-β 1 formulation was biologically inactive. Several growth or differentiation factors have been suggested to accelerate degradation of biomaterials used as carriers. The objective of this study was to evaluate possible activity of rhTGF-β 1 on biodegradation of the calcium carbonate carrier. rhTGF-β 1 in a putty-formulated particulate calcium carbonate carrier was implanted into critical-size, supraalveolar periodontal defects under conditions for GTR in five beagle dogs. Contralateral defects received the calcium carbonate carrier combined with GTR without rhTGF-β 1 (control). The animals were euthanized at week 4 post-surgery and block biopsies of the defect sites were collected for histologic and histometric analysis. Radiographs were obtained at defect creation and weeks 2 and 4 after defect creation. No statistically significant differences were observed in new bone formation (bone height and area) among the treatments. However, total residual carrier was significantly reduced in sites receiving rhTGF-β 1 compared to control (P = 0.04). Similarly, carrier density was considerably reduced in sites receiving rhTGF-β 1 compared to control; the difference was borderline statistically significant (P = 0.06). Within the limitations of the study, it may be concluded that rhTGF-β 1 accelerates biodegradation of a particulate calcium carbonate biomaterial, indicating a biologic activity of the rhTGF-β 1 formulation apparently not encompassing enhanced or accelerated periodontal regeneration. © 2007

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

Cutting Edge: Defective Aerobic Glycolysis Defines the Distinct Effector Function in Antigen-Activated CD8+ Recent Thymic Emigrants.

PubMed

Cunningham, Cody A; Bergsbaken, Tessa; Fink, Pamela J

2017-06-15

Recent thymic emigrants (RTEs) are the youngest peripheral T cells that have completed thymic selection and egress to the lymphoid periphery. RTEs are functionally distinct from their more mature but still naive T cell counterparts, because they exhibit dampened proliferation and reduced cytokine production upon activation. In this article, we show that, compared with more mature but still naive T cells, RTEs are impaired in their ability to perform aerobic glycolysis following activation. Impaired metabolism underlies the reduced IFN-γ production observed in activated RTEs. This failure to undergo Ag-induced aerobic glycolysis is caused by reduced mTORC1 activity and diminished Myc induction in RTEs. Critically, exogenous IL-2 restores Myc expression in RTEs, driving aerobic glycolysis and IFN-γ production to the level of mature T cells. These results reveal a previously unknown metabolic component to postthymic T cell maturation. Copyright © 2017 by The American Association of Immunologists, Inc.

Inhibiting aerobic glycolysis suppresses renal interstitial fibroblast activation and renal fibrosis.

PubMed

Ding, Hao; Jiang, Lei; Xu, Jing; Bai, Feng; Zhou, Yang; Yuan, Qi; Luo, Jing; Zen, Ke; Yang, Junwei

2017-09-01

Chronic kidney diseases generally lead to renal fibrosis. Despite great progress having been made in identifying molecular mediators of fibrosis, the mechanism that governs renal fibrosis remains unclear, and so far no effective therapeutic antifibrosis strategy is available. Here we demonstrated that a switch of metabolism from oxidative phosphorylation to aerobic glycolysis (Warburg effect) in renal fibroblasts was the primary feature of fibroblast activation during renal fibrosis and that suppressing renal fibroblast aerobic glycolysis could significantly reduce renal fibrosis. Both gene and protein assay showed that the expression of glycolysis enzymes was upregulated in mouse kidneys with unilateral ureter obstruction (UUO) surgery or in transforming growth factor-β1 (TGF-β1)-treated renal interstitial fibroblasts. Aerobic glycolysis flux, indicated by glucose uptake and lactate production, was increased in mouse kidney with UUO nephropathy or TGF-β1-treated renal interstitial fibroblasts and positively correlated with fibrosis process. In line with this, we found that increasing aerobic glycolysis can remarkably induce myofibroblast activation while aerobic glycolysis inhibitors shikonin and 2-deoxyglucose attenuate UUO-induced mouse renal fibrosis and TGF-β1-stimulated myofibroblast activation. Furthermore, mechanistic study indicated that shikonin inhibits renal aerobic glycolysis via reducing phosphorylation of pyruvate kinase type M2, a rate-limiting glycolytic enzyme associated with cell reliance on aerobic glycolysis. In conclusion, our findings demonstrate the critical role of aerobic glycolysis in renal fibrosis and support treatment with aerobic glycolysis inhibitors as a potential antifibrotic strategy. Copyright © 2017 the American Physiological Society.

Role of BMP receptor traffic in synaptic growth defects in an ALS model.

PubMed

Deshpande, Mugdha; Feiger, Zachary; Shilton, Amanda K; Luo, Christina C; Silverman, Ethan; Rodal, Avital A

2016-10-01

TAR DNA-binding protein 43 (TDP-43) is genetically and functionally linked to amyotrophic lateral sclerosis (ALS) and regulates transcription, splicing, and transport of thousands of RNA targets that function in diverse cellular pathways. In ALS, pathologically altered TDP-43 is believed to lead to disease by toxic gain-of-function effects on RNA metabolism, as well as by sequestering endogenous TDP-43 and causing its loss of function. However, it is unclear which of the numerous cellular processes disrupted downstream of TDP-43 dysfunction lead to neurodegeneration. Here we found that both loss and gain of function of TDP-43 in Drosophila cause a reduction of synaptic growth-promoting bone morphogenic protein (BMP) signaling at the neuromuscular junction (NMJ). Further, we observed a shift of BMP receptors from early to recycling endosomes and increased mobility of BMP receptor-containing compartments at the NMJ. Inhibition of the recycling endosome GTPase Rab11 partially rescued TDP-43-induced defects in BMP receptor dynamics and distribution and suppressed BMP signaling, synaptic growth, and larval crawling defects. Our results indicate that defects in receptor traffic lead to neuronal dysfunction downstream of TDP-43 misregulation and that rerouting receptor traffic may be a viable strategy for rescuing neurological impairment. © 2016 Deshpande, Feiger, et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Layer-by-Layer Epitaxial Growth of Defect-Engineered Strontium Cobaltites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Andersen, Tassie K.; Cook, Seyoung; Wan, Gang

Control over structure and composition of (ABO(3)) perovskite oxides offers exciting opportunities since these materials possess unique, tunable properties. Perovskite oxides with cobalt B-site cations are particularly promising, as the range of the cations stable oxidation states leads to many possible structural frameworks. Here, we report growth of strontium cobalt oxide thin films by molecular beam epitaxy, and conditions necessary to stabilize different defect concentration phases. In situ X-ray scattering is used to monitor structural evolution during growth, while in situ X-ray absorption near-edge spectroscopy is used to probe oxidation state and measure changes to oxygen vacancy concentration as amore » function of film thickness. Experimental results are compared to kinetically limited thermodynamic predictions, in particular, solute trapping, with semiquantitative agreement. Agreement between observations of dependence of cobaltite phase on oxidation activity and deposition rate, and predictions indicates that a combined experimental/theoretical approach is key to understanding phase behavior in the strontium cobalt oxide system.« less

Time series analysis of aerobic bacterial flora during Miso fermentation.

PubMed

Onda, T; Yanagida, F; Tsuji, M; Shinohara, T; Yokotsuka, K

2003-01-01

This article reports a microbiological study of aerobic mesophilic bacteria that are present during the fermentation process of Miso. Aerobic bacteria were enumerated and isolated from Miso during fermentation and divided into nine groups using traditional phenotypic tests. The strains were identified by biochemical analysis and 16S rRNA sequence analysis. They were identified as Bacillus subtilis, B. amyloliquefaciens, Kocuria kristinae, Staphylococcus gallinarum and S. kloosii. All strains were sensitive to the bacteriocins produced by the lactic acid bacteria isolated from Miso. The dominant species among the undesirable species throughout the fermentation process were B. subtilis and B. amyloliquefaciens. It is suggested that bacteriocin-producing lactic acid bacteria are effective in the growth prevention of aerobic bacteria in Miso. This study has provided useful information for controlling of bacterial flora during Miso fermentation.

Observation of defects evolution in electronic materials

NASA Astrophysics Data System (ADS)

Jang, Jung Hun

Advanced characterization techniques have been used to obtain a better understanding of the microstructure of electronic materials. The structural evolution, especially defects, has been investigated during the film growth and post-growth processes. Obtaining the relation between the defect evolution and growth/post-growth parameters is very important to obtain highly crystalline films. In this work, the growth and post-growth related defects in GaN, ZnO, strained-Si/SiGe films have been studied using several advanced characterization techniques. First of all, the growth of related defects in GaN and p-type ZnO films have been studied. The effect of growth parameters, such as growth temperature, gas flow rate, dopants used during the deposition, on the crystalline quality of the GaN and ZnO layers was investigated by high resolution X-ray diffraction (HRXRD) and transmission electron microscopy (TEM). In GaN films, it was found that the edge and mixed type threading dislocations were the dominant defects so that the only relevant figure of merit (FOM) for the crystalline quality should be the FWHM value of o-RC of the surface perpendicular plane which could be determined by a grazing incidence x-ray diffraction (GIXD) technique as shown in this work. The understanding of the relationship between the defect evolution and growth parameters allowed for the growth of high crystalline GaN films. For ZnO films, it was found that the degree of texture and crystalline quality of P-doped ZnO films decreased with increasing the phosphorus atomic percent. In addition, the result from the x-ray diffraction line profile analysis showed that the 0.5 at % P-doped ZnO film showed much higher microstrain than the 1.0 at % P-doped ZnO film, which indicated that the phosphorus atoms were segregated with increasing P atomic percentage. Finally, post-growth related defects in strained-Si/SiGe films were investigated. Postgrowth processes used in this work included high temperature N2

Settling properties of aerobic granular sludge (AGS) and aerobic granular sludge molasses (AGSM)

NASA Astrophysics Data System (ADS)

Mat Saad, Azlina; Aini Dahalan, Farrah; Ibrahim, Naimah; Yasina Yusuf, Sara; Aqlima Ahmad, Siti; Khalil, Khalilah Abdul

2018-03-01

Aerobic granulation technology is applied to treat domestic and industrial wastewater. The Aerobic granular sludge (AGS) cultivated has strong properties that appears to be denser and compact in physiological structure compared to the conventional activated sludge. It offers rapid settling for solid:liquid separation in wastewater treatment. Aerobic granules were developed using sequencing batch reactor (SBR) with intermittent aerobic - anaerobic mode with 8 cycles in 24 hr. This study examined the settling velocity performance of cultivated aerobic granular sludge (AGS) and aerobic granular sludge molasses (AGSM). The elemental composition in both AGS and AGSM were determined using X-ray fluorescence (XRF). The results showed that AGSM has higher settling velocity 30.5 m/h compared to AGS.

Examining physiotherapist use of structured aerobic exercise testing to decrease barriers to aerobic exercise.

PubMed

Foster B Sc, Evan; Fraser, Julia E; Inness PhD, Elizabeth L; Munce, Sarah; Biasin, Louis; Poon, Vivien; Bayley, Mark

2018-04-03

To determine the frequency of physiotherapist-administered aerobic exercise testing/training, the proportion of physiotherapists who administer this testing/training, and the barriers that currently exist across different practice environments. A secondary objective is to identify the learning needs of physiotherapists for the development of an education curriculum in aerobic exercise testing and training with electrocardiograph (ECG) administration and interpretation. National, cross-sectional survey. Registered physiotherapists practicing in Canada. Out of 137 participants, most (75%) physiotherapists prescribed aerobic exercise on a regular basis (weekly); however, 65% had never conducted an aerobic exercise test. There were no significant differences in frequency of aerobic exercise testing across different practice environments or across years of physiotherapy experience. Physiotherapists perceived the main barriers to aerobic exercise testing as being a lack of equipment/space (78%), time (65%), and knowledge (56%). Although most (82%) were uncomfortable administering 12-lead ECG-monitored aerobic exercise tests, 60% stated they would be interested in learning more about ECG interpretation. This study found that physiotherapists are regularly implementing aerobic exercise. This exercise was infrequently guided by formal aerobic exercise testing, which could increase access to safe and effective exercise within the optimal aerobic training zone. As well, this could facilitate training in patients with cardiovascular diagnoses that require additional testing for medical clearance. Increased ECG training and access to equipment for physiotherapists may augment pre-screening aerobic exercise testing. This training should include learning the key arrhythmias for aerobic exercise test termination as defined by the American College of Sports Medicine.

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

PubMed

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

2016-01-21

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.

Overexpression of a truncated CTF7 construct leads to pleiotropic defects in reproduction and vegetative growth in Arabidopsis.

PubMed

Liu, Desheng; Makaroff, Christopher A

2015-03-05

Eco1/Ctf7 is essential for the establishment of sister chromatid cohesion during S phase of the cell cycle. Inactivation of Ctf7/Eco1 leads to a lethal phenotype in most organisms. Altering Eco1/Ctf7 levels or point mutations in the gene can lead to alterations in nuclear division as well as a wide range of developmental defects. Inactivation of Arabidopsis CTF7 (AtCTF7) results in severe defects in reproduction and vegetative growth. To further investigate the function(s) of AtCTF7, a tagged version of AtCTF7 and several AtCTF7 deletion constructs were created and transformed into wild type or ctf7 +/- plants. Transgenic plants expressing 35S:NTAP:AtCTF7∆299-345 (AtCTF7∆B) displayed a wide range of phenotypic alterations in reproduction and vegetative growth. Male meiocytes exhibited chromosome fragmentation and uneven chromosome segregation. Mutant ovules contained abnormal megasporocyte-like cells during pre-meiosis, megaspores experienced elongated meiosis and megagametogenesis, and defective megaspores/embryo sacs were produced at various stages. The transgenic plants also exhibited a broad range of vegetative defects, including meristem disruption and dwarfism that were inherited in a non-Mendelian fashion. Transcripts for epigenetically regulated transposable elements (TEs) were elevated in transgenic plants. Transgenic plants expressing 35S:AtCTF7∆B displayed similar vegetative defects, suggesting the defects in 35S:NTAP:AtCTF7∆B plants are caused by high-level expression of AtCTF7∆B. High level expression of AtCTF7∆B disrupts megasporogenesis, megagametogenesis and male meiosis, as well as causing a broad range of vegetative defects, including dwarfism that are inherited in a non-Mendelian fashion.

Substrate preparation effects on defect density in molecular beam epitaxial growth of CdTe on CdTe (100) and (211)B

DOE PAGES

Burton, George L.; Diercks, David R.; Perkins, Craig L.; ...

2017-07-01

Recent studies have demonstrated that growth of CdTe on CdTe (100) and (211)B substrates via molecular beam epitaxy (MBE) results in planar defect densities 2 and 3 orders of magnitude higher than growth on InSb (100) substrates, respectively. To understand this shortcoming, MBE growth on CdTe substrates with a variety of substrate preparation methods is studied by scanning electron microscopy, secondary ion mass spectrometry, x-ray photoelectron spectroscopy, cross sectional transmission electron microscopy, and atom probe tomography (APT). Prior to growth, carbon is shown to remain on substrate surfaces even after atomic hydrogen cleaning. APT revealed that following the growth ofmore » films, trace amounts of carbon remained at the substrate/film interface. This residual carbon may lead to structural degradation, which was determined as the main cause of higher defect density.« less

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.

A quasi-universal medium to break the aerobic/anaerobic bacterial culture dichotomy in clinical microbiology.

PubMed

Dione, N; Khelaifia, S; La Scola, B; Lagier, J C; Raoult, D

2016-01-01

In the mid-19th century, the dichotomy between aerobic and anaerobic bacteria was introduced. Nevertheless, the aerobic growth of strictly anaerobic bacterial species such as Ruminococcus gnavus and Fusobacterium necrophorum, in a culture medium containing antioxidants, was recently demonstrated. We tested aerobically the culture of 623 bacterial strains from 276 bacterial species including 82 strictly anaerobic, 154 facultative anaerobic, 31 aerobic and nine microaerophilic bacterial species as well as ten fungi. The basic culture medium was based on Schaedler agar supplemented with 1 g/L ascorbic acid and 0.1 g/L glutathione (R-medium). We successively optimized this media, adding 0.4 g/L uric acid, using separate autoclaving of the component, or adding haemin 0.1 g/L or α-ketoglutarate 2 g/L. In the basic medium, 237 bacterial species and ten fungal species grew but with no growth of 36 bacterial species, including 22 strict anaerobes. Adding uric acid allowed the growth of 14 further species including eight strict anaerobes, while separate autoclaving allowed the growth of all tested bacterial strains. To extend its potential use for fastidious bacteria, we added haemin for Haemophilus influenzae, Haemophilus parainfluenzae and Eikenella corrodens and α-ketoglutarate for Legionella pneumophila. This medium allowed the growth of all tested strains with the exception of Mycobacterium tuberculosis and Mycobacterium bovis. Testing primoculture and more fastidious species will constitute the main work to be done, but R-medium coupled with a rapid identification method (matrix-assisted laser desorption/ionization time-of-flight mass spectrometry) will facilitate the anaerobic culture in clinical microbiology laboratories. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Effects of sublethal concentrations of silver nanoparticles on Escherichia coli and Bacillus subtilis under aerobic and anaerobic conditions.

PubMed

Garuglieri, Elisa; Cattò, Cristina; Villa, Federica; Zanchi, Raffaella; Cappitelli, Francesca

2016-12-16

The present work is aimed at comparing the effects of sublethal concentrations of silver nanoparticles (AgNPs) on the growth kinetic, adhesion ability, oxidative stress, and phenotypic changes of model bacteria (Escherichia coli and Bacillus subtilis) under both aerobic and anaerobic conditions. Growth kinetic tests conducted in 96-well microtiter plates revealed that sublethal concentrations of AgNPs do not affect E. coli growth, whereas 1 μg/ml AgNPs increased B. subtilis growth rate under aerobic conditions. At the same concentration, AgNPs promoted B. subtilis adhesion, while it discouraged E. coli attachment to the surface in the presence of oxygen. As determined by 2,7-dichlorofluorescein-diacetate assays, AgNPs increased the formation of intracellular reactive oxygen species, but not at the highest concentrations, suggesting the activation of scavenging systems. Finally, motility assays revealed that 0.01 and 1 μg/ml AgNPs, respectively, promoted surface movement in E. coli and B. subtilis under aerobic and anaerobic conditions. The results demonstrate that E. coli and B. subtilis react differently from AgNPs over a wide range of sublethal concentrations examined under both aerobic and anaerobic conditions. These findings will help elucidate the behavior and impact of engineered nanoparticles on microbial ecosystems.

Effects of aerobic exercise on mild cognitive impairment: a controlled trial.

PubMed

Baker, Laura D; Frank, Laura L; Foster-Schubert, Karen; Green, Pattie S; Wilkinson, Charles W; McTiernan, Anne; Plymate, Stephen R; Fishel, Mark A; Watson, G Stennis; Cholerton, Brenna A; Duncan, Glen E; Mehta, Pankaj D; Craft, Suzanne

2010-01-01

To examine the effects of aerobic exercise on cognition and other biomarkers associated with Alzheimer disease pathology for older adults with mild cognitive impairment, and assess the role of sex as a predictor of response. Six-month, randomized, controlled, clinical trial. Veterans Affairs Puget Sound Health Care System clinical research unit. Thirty-three adults (17 women) with amnestic mild cognitive impairment ranging in age from 55 to 85 years (mean age, 70 years). Intervention Participants were randomized either to a high-intensity aerobic exercise or stretching control group. The aerobic group exercised under the supervision of a fitness trainer at 75% to 85% of heart rate reserve for 45 to 60 min/d, 4 d/wk for 6 months. The control group carried out supervised stretching activities according to the same schedule but maintained their heart rate at or below 50% of their heart rate reserve. Before and after the study, glucometabolic and treadmill tests were performed and fat distribution was assessed using dual-energy x-ray absorptiometry. At baseline, month 3, and month 6, blood was collected for assay and cognitive tests were administered. Performance measures on Symbol-Digit Modalities, Verbal Fluency, Stroop, Trails B, Task Switching, Story Recall, and List Learning. Fasting plasma levels of insulin, cortisol, brain-derived neurotrophic factor, insulinlike growth factor-I, and beta-amyloids 40 and 42. Six months of high-intensity aerobic exercise had sex-specific effects on cognition, glucose metabolism, and hypothalamic-pituitary-adrenal axis and trophic activity despite comparable gains in cardiorespiratory fitness and body fat reduction. For women, aerobic exercise improved performance on multiple tests of executive function, increased glucose disposal during the metabolic clamp, and reduced fasting plasma levels of insulin, cortisol, and brain-derived neurotrophic factor. For men, aerobic exercise increased plasma levels of insulinlike growth factor I

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

Layer-by-layer epitaxial growth of defect-engineered strontium cobaltites

DOE PAGES

Andersen, Tassie K.; Cook, Seyoung; Wan, Gang; ...

2018-01-18

Here, control over structure and composition of (ABO 3) perovskite oxides offers exciting opportunities since these materials possess unique, tunable properties. Perovskite oxides with cobalt B-site cations are particularly promising, as the range of the cation’s stable oxidation states leads to many possible structural frameworks. Here, we report growth of strontium cobalt oxide thin films by molecular beam epitaxy, and conditions necessary to stabilize different defect concentration phases. In situ X-ray scattering is used to monitor structural evolution during growth, while in situ X-ray absorption near-edge spectroscopy is used to probe oxidation state and measure changes to oxygen vacancy concentrationmore » as a function of film thickness. Experimental results are compared to kinetically-limited thermodynamic predictions, in particular, solute trapping, with semi-quantitative agreement. Agreement between observations of dependence of cobaltite phase on oxidation activity and deposition rate, and predictions indicates that a combined experimental/theoretical approach is key to understanding phase behavior in the strontium cobalt oxide system.« less

Layer-by-layer epitaxial growth of defect-engineered strontium cobaltites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Andersen, Tassie K.; Cook, Seyoung; Wan, Gang

Here, control over structure and composition of (ABO 3) perovskite oxides offers exciting opportunities since these materials possess unique, tunable properties. Perovskite oxides with cobalt B-site cations are particularly promising, as the range of the cation’s stable oxidation states leads to many possible structural frameworks. Here, we report growth of strontium cobalt oxide thin films by molecular beam epitaxy, and conditions necessary to stabilize different defect concentration phases. In situ X-ray scattering is used to monitor structural evolution during growth, while in situ X-ray absorption near-edge spectroscopy is used to probe oxidation state and measure changes to oxygen vacancy concentrationmore » as a function of film thickness. Experimental results are compared to kinetically-limited thermodynamic predictions, in particular, solute trapping, with semi-quantitative agreement. Agreement between observations of dependence of cobaltite phase on oxidation activity and deposition rate, and predictions indicates that a combined experimental/theoretical approach is key to understanding phase behavior in the strontium cobalt oxide system.« less

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. Copyright © 2015 Elsevier Ltd. All rights reserved.

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. Copyright © 2016 Elsevier B.V. All rights reserved.

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. Copyright © 2015 Elsevier Inc. All rights reserved.

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. Copyright © 2014 Elsevier B.V. All rights reserved.

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)

Tumor vessel normalization after aerobic exercise enhances chemotherapeutic efficacy.

PubMed

Schadler, Keri L; Thomas, Nicholas J; Galie, Peter A; Bhang, Dong Ha; Roby, Kerry C; Addai, Prince; Till, Jacob E; Sturgeon, Kathleen; Zaslavsky, Alexander; Chen, Christopher S; Ryeom, Sandra

2016-10-04

Targeted therapies aimed at tumor vasculature are utilized in combination with chemotherapy to improve drug delivery and efficacy after tumor vascular normalization. Tumor vessels are highly disorganized with disrupted blood flow impeding drug delivery to cancer cells. Although pharmacologic anti-angiogenic therapy can remodel and normalize tumor vessels, there is a limited window of efficacy and these drugs are associated with severe side effects necessitating alternatives for vascular normalization. Recently, moderate aerobic exercise has been shown to induce vascular normalization in mouse models. Here, we provide a mechanistic explanation for the tumor vascular normalization induced by exercise. Shear stress, the mechanical stimuli exerted on endothelial cells by blood flow, modulates vascular integrity. Increasing vascular shear stress through aerobic exercise can alter and remodel blood vessels in normal tissues. Our data in mouse models indicate that activation of calcineurin-NFAT-TSP1 signaling in endothelial cells plays a critical role in exercise-induced shear stress mediated tumor vessel remodeling. We show that moderate aerobic exercise with chemotherapy caused a significantly greater decrease in tumor growth than chemotherapy alone through improved chemotherapy delivery after tumor vascular normalization. Our work suggests that the vascular normalizing effects of aerobic exercise can be an effective chemotherapy adjuvant.

Catch-up growth in term and preterm infants after surgical closure of ventricular septal defect in the first year of life.

PubMed

Correia Martins, Luísa; Lourenço, Rita; Cordeiro, Susana; Carvalho, Nuno; Mendes, Inês; Loureiro, Marisa; Patrício, Miguel; Anjos, Rui

2016-04-01

Growth impairment in infants with unrestrictive ventricular septal defects (VSD) is common, and normalisation of growth has been reported after surgical correction. Literature is inconsistent about growth velocity after surgery in term and preterm infants. We aimed to establish the pattern of catch-up growth in term and preterm infants submitted to VSD surgical correction before 1 year of age. Fifty-two infants (41 term, 11 preterm) were studied. Anthropometric data at birth, surgery and 3, 6, 12 and 24 months after surgery were collected retrospectively. Statistic analyses were performed in SPSS® version 21. At the time of surgery, growth was severely impaired in term and preterm infants. Term infants underwent a period of fast growth within the first 6 months after surgery, achieving posteriorly a normal growth pattern, as both weight and height were not significantly different from the reference population at 24 months after surgery. Preterms caught-up later than term infants but with a significant weight gain within 3 months after surgery. Early surgical repair of VSD leads to a significant acceleration of growth within 3 to 6 months after surgery, for both groups. • Growth impairment in infants with unrestrictive ventricular septal defects is well documented in literature. • Surgical correction in the first months of life is the current option for most ventricular septal defects, leading to a more favourable growth pattern. • Rapid growth during infancy may be associated with the development of insulin resistance, metabolic syndrome, obesity and cardiovascular disease later in life. What is New: • Literature is inconsistent about catch-up growth velocities after ventricular correction for term infants. • Preterm infants have never been enrolled in previous studies that aimed to establish a pattern of growth after surgery. • This group of children, who underwent a rapid post-surgery catch-up growth that follows a period of failure to thrive, may be

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.

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.

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

USDA-ARS?s Scientific Manuscript database

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 ...

Aerobic exercise (image)

MedlinePlus

Aerobic exercise gets the heart working to pump blood through the heart more quickly and with more ... must be oxygenated more quickly, which quickens respiration. Aerobic exercise strengthens the heart and boosts healthy cholesterol ...

Alternating anoxic feast/aerobic famine condition for improving granular sludge formation in sequencing batch airlift reactor at reduced aeration rate.

PubMed

Wan, Junfeng; Bessière, Yolaine; Spérandio, Mathieu

2009-12-01

In this study the influence of a pre-anoxic feast period on granular sludge formation in a sequencing batch airlift reactor is evaluated. Whereas a purely aerobic SBR was operated as a reference (reactor R2), another reactor (R1) was run with a reduced aeration rate and an alternating anoxic-aerobic cycle reinforced by nitrate feeding. The presence of pre-anoxic phase clearly improved the densification of aggregates and allowed granular sludge formation at reduced air flow rate (superficial air velocity (SAV)=0.63cms(-1)). A low sludge volume index (SVI(30)=45mLg(-1)) and a high MLSS concentration (9-10gL(-1)) were obtained in the anoxic/aerobic system compared to more conventional results for the aerobic reactor. A granular sludge was observed in the anoxic/aerobic system whilst only flocs were observed in the aerobic reference even when operated at a high aeration rate (SAV=2.83cms(-1)). Nitrification was maintained efficiently in the anoxic/aerobic system even when organic loading rate (OLR) was increased up to 2.8kgCODm(-3)d(-1). In the contrary nitrification was unstable in the aerobic system and dropped at high OLR due to competition between autotrophic and heterotrophic growth. The presence of a pre-anoxic period positively affected granulation process via different mechanisms: enhancing heterotrophic growth/storage deeper in the internal anoxic layer of granule, reducing the competition between autotrophic and heterotrophic growth. These processes help to develop dense granular sludge at a moderate aeration rate. This tends to confirm that oxygen transfer is the most limiting factor for granulation at reduced aeration. Hence the use of an alternative electron acceptor (nitrate or nitrite) should be encouraged during feast period for reducing energy demand of the granular sludge process.

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;…

Recombinant human basic fibroblast growth factor (bFGF) stimulates periodontal regeneration in class II furcation defects created in beagle dogs.

PubMed

Murakami, S; Takayama, S; Kitamura, M; Shimabukuro, Y; Yanagi, K; Ikezawa, K; Saho, T; Nozaki, T; Okada, H

2003-02-01

Several growth factors (or cytokines) have been recently investigated for their use as potential therapeutics for periodontal tissue regeneration. The objective of this study was to evaluate periodontal tissue regeneration, including new bone and cementum formation, following topical application of recombinant basic fibroblast growth factor (bFGF, FGF-2) to furcation class II defects. Twelve furcation class II bone defects were surgically created in six beagle dogs, then recombinant bFGF (30 micro g/site) + gelatinous carrier was topically applied to the bony defects. Six weeks after application, periodontal regeneration was analyzed. In all sites where bFGF was applied, periodontal ligament formation with new cementum deposits and new bone formation was observed histomorphometrically, in amounts greater than in the control sites. Basic FGF-applied sites exhibited significant regeneration as represented by the new bone formation rate (NBR) (83.6 +/- 14.3%), new trabecular bone formation rate (NTBR) (44.1 +/- 9.5%), and new cementum formation rate (NCR) (97.0 +/- 7.5%). In contrast, in the carrier-only sites, the NBR, NTBR, and NCR were 35.4 +/- 8.9%, 16.6 +/- 6.2%, and 37.2 +/- 15.1%, respectively. Moreover, no instances of epithelial down growth, ankylosis, or root resorption were observed in the bFGF-applied sites examined. The present results indicate that topical application of bFGF can enhance considerable periodontal regeneration in artificially created furcation class II bone defects of beagle dogs.

Comparison of aerobic conjunctival bacterial flora in pregnant, reproductive-aged and postmenopausal women

PubMed Central

Balikoglu-Yilmaz, Melike; Sen, Emine; Sevket, Osman; Polat, Yusuf; Karabulut, Aysun; Uysal, Omer

2012-01-01

AIM To evaluate the effect of hormonal status on aerobic conjunctival flora in women. METHODS One hundred fifty-eight women [reproductive-aged (n=55), pregnant (n=51), and postmenopausal (n=52)] who admitted to outpatient clinic of Obstetrics and Gynecology Department of Denizli State Hospital were enrolled. Age, body-mass index (BMI), obstetric history, cigarette smoking, drug usage, presence of systemic disease, and intraocular pressure (IOP) were recorded for each patient. The samples were taken from the lower fornix with two culture swabs and directly incubated in culture containing 5% sheep blood, eosin-methylene blue and chocolate agar. The other swab specimen was Gram stained. All growths and microscopic results were analyzed. RESULTS The coagulase-negative Staphylococcus was the predominant organism isolated in the conjunctival samples in both three groups. The aerobic microorganism growth rate for all isolated aerobic organisms revealed no significant change in the three groups (P >0.05). The conjunctival culture positivity rates were similar in the three groups (49% in reproductive-aged, 57% in pregnant and 58% in postmenopausal women) (P >0.05). Age, IOP, BMI, gravidity, parity, cigarette smoking, drug usage, and presence of systemic diseases did not have an effect on culture positivity in three groups. CONCLUSION Results of this study showed that conjunctival aerobic flora and bacterial colonization did not differ between reproductive-aged, pregnant and postmenopausal women. PMID:23275909

Tibial tunnel defect size as a risk factor in growth arrest following paediatric transphyseal anterior cruciate ligament reconstruction: an anatomical study.

PubMed

Pananwala, Hasitha; Jabbar, Yaser; Mills, Leonora; Symes, Michael; Nandapalan, Haren; Sefton, Andrew; Delungahawatte, Lasitha; Dao, Quang

2016-09-01

There is ongoing controversy regarding growth disturbances in younger patients undergoing anterior cruciate ligament reconstructions. Animal models have shown that an injury of 7-9% of the physeal area is a risk factor for growth disturbances. A total of 39 magnetic resonance imaging studies of the knee were examined. The proximal tibial physeal area was determined using a calibrated 'region of interest' ligature encompassing the tibial physis in the axial plane. The potential defect left by commonly used drill sizes was calculated as a percentage of the physeal area. A 7-mm drill leaves a mean defect of 1.45% physeal area (range: 1.11-1.89%, SD: 0.28, 95% CI: ±0.09), 8-mm drill leaves a 1.84% mean defect (range: 1.43-2.49%, SD: 0.38, 95% CI: ±0.12) and a 9-mm drill leaves a 2.30% mean defect (range: 1.83-3.19%, SD: 0.58, 95% CI: ±0.17). At 55°, 7-mm drill leaves a mean defect of 1.96% (range: 1.32-2.28%, SD: 0.37, 95% CI: ±0.12), 8-mm drill leaves a mean defect of 2.19% (range: 1.71-2.95%, SD: 0.46, 95% CI: ±0.14) and a 9-mm drill leaves a mean defect of 2.76% (range: 2.16-3.73%, SD: 0.58, 95% CI: ±0.18). There was a statistically significant difference in the tunnel area with a change of drill angle (7-mm drill P = 0.005, 8-mm drill P = 0.001, 9-mm drill P = 0.001). On the basis of this study in the context of animal model and observational evidence, the area of physeal injury using drill tunnels for anterior cruciate ligament reconstruction would not appear to contribute to potential growth disturbances. © 2016 Royal Australasian College of Surgeons.

Characteristics of aerobic granules grown on glucose and acetate in sequential aerobic sludge blanket reactors.

PubMed

Tay, J H; Liu, Q S; Liu, Y

2002-08-01

Aerobic granules were cultivated in two column-type sequential aerobic sludge blanket reactors fed with glucose and acetate, respectively. The characteristics of aerobic granules were investigated. Results indicated that the glucose- and acetate-fed granules have comparable characteristics in terms of settling velocity, size, shape, biomass density, hydrophobicity, physical strength, microbial activity and storage stability. Substrate component does not seem to be a key factor on the formation of aerobic granules. However, microbial diversity of the granules is closely associated with the carbon sources supplied to the reactors. Compared with the conventional activated sludge flocs, aerobic granules exhibit excellent physical characteristics that would be essential for industrial application. This research provides a complete set of characteristics data of aerobic granules grown on glucose and acetate, which would be useful for further development of aerobic granules-based compact bioreactor for handling high strength organic wastewater.

Growth and defects of explosives crystals

NASA Astrophysics Data System (ADS)

Cady, H. H.

Large single crystals of PETN, RDX, and TNT can be grown easily from evaporating ethyl acetate solutions. The crystals all share a similar type of defect that may not be commonly recognized. The defect generates conical faces, ideally mosaic crystals, and may account for the 'polymorphs' of TNT and detonator grades of PETN. TATB crystals manufactured by the amination of trichlorotrinitrobenzene in dry toluene entrain two forms of ammonium chloride. One of these forms causes 'worm holes' in the TATB crystals that may be the reason for its unusually low failure diameters. Strained HMX crystals form mechanical twins that can spontaneously revert back to the untwinned form when the straining force is removed. Large strains or temperatures above 100 C lock in the mechanical twins.

Combined anaerobic/aerobic digestion: effect of aerobic retention time on nitrogen and solids removal.

PubMed

Kim, Jongmin; Novak, John T

2011-09-01

A combined anaerobic/aerobic sludge digestion system was studied to determine the effect of aerobic solids retention time (SRT) on its solids and nitrogen removal efficiencies. After the anaerobic digester reached steady state, effluent from the anaerobic digester was fed to aerobic digesters that were operated at 2- to 5-day SRTs. The anaerobic system was fed with a mixture of primary and secondary sludge from a local municipal wastewater treatment plant. Both systems were fed once per a day. The aerobic reactor was continuously aerated with ambient air, maintaining dissolved oxygen level at 1.1 +/- 0.3 mg/L. At a 4-day or longer SRT, more than 11% additional volatile solids and 90% or greater ammonia were removed in the aerobic digester, while 32.8 mg-N/L or more nitrite/nitrate also was measured. Most total Kjeldahl nitrogen removal was via ammonia removal, while little organic nitrogen was removed in the aerobic digester.

Conversion of xylose to ethanol under aerobic conditions by Candida tropicalis

Treesearch

T. W. Jeffries

1981-01-01

Candida tropicalis converts xylose to ethanol under aerobic, but not anaerobic, conditions. Ethanol production lags behind growth and is accelerated by increased aeration. Adding xylose to active cultures stimulates ethanol production as does serial subculture in a medium containing xylose as a sole carbon source.

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. Copyright © 2010 S. Karger AG, Basel.

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

Growth of E. coli at Nanomolar Concentrations of Oxygen

NASA Astrophysics Data System (ADS)

Stolper, D. A.; Revsbech, N.; Canfield, D. E.

2009-12-01

It has been know since the work of Pasteur (1876) that facultative aerobes transition from aerobic to anaerobic metabolisms when molecular oxygen (O2) is removed from the environment. This transition (the “Pasteur Point”) generally occurs when the O2 concentration in gas in equilibrium with a growth medium is ~.01 of the present atmospheric level (PAL) of O2 (Fenchel and Finlay, 1995). In the earth sciences, the Pasteur Point is sometimes assumed to approximate the O2 level below which aerobic processes cease to be viable (e.g., Goldblatt et al., 2006; Parkinson et al., 2008). If true, this assumption implies that aerobic respiration evolved only after the earth’s atmosphere reached O2 concentrations ≥ .01 PAL. In order to investigate whether the Pasteur Point is a valid proxy for the level at which aerobic metabolisms become non-viable, we designed an experiment in which the presence or absence of aerobic respiration could be measured at O2 concentrations significantly below the Pasteur Point. To do this, we grew E. coli K-12 in a sealed, 1 liter glass reactor with well-mixed M9 media maintained at 37°C. O2 was supplied to the reactor by pumping air-saturated water (maintained at 37°C) through a silicone tube that looped through the reactor. The only carbon source available was glycerol. As E. coli K-12 can only metabolize glycerol by using O2 (except under restricted conditions not present in our experimental setup), growth of E. coli K-12 in the medium signifies aerobic growth. We monitored growth by periodically removing media and measuring its optical density spectrophotometrically. In order to monitor O2 concentrations, we employed a new O2-sensing electrode, termed the “Switchable Trace Oxygen Electrode” (STOX) sensor, which can measure O2 concentrations in solutions down to ~3-5 nM (Revsbech et al., 2009). This corresponds to an equilibrated gas with ~10-5 PAL. Our findings indicate that E. coli K-12 can grow aerobically at O2 levels up to

Aerobic treatment of swine manure to enhance anaerobic digestion and microalgal cultivation.

PubMed

Bekoe, Dominic; Wang, Lijun; Zhang, Bo; Scott Todd, Matthew; Shahbazi, Abolghasem

2018-02-01

Aerobic treatment of swine manure was coupled with anaerobic digestion and microalgal cultivation. A 14-day aerobic treatment reduced the total solid content of swine manure by >15%. Ammonia and carbon dioxide were stripped by the air supplied, and this off-gas was further used to aerate the culture of Chlorella vulgaris. The microalgal growth rates in Bristol medium and the wastewater with the off-gas increased from 0.08 to 0.22 g/L/d and from 0.15 to 0.24 g/L/d, respectively. Meanwhile, the aerobically treated swine manure showed a higher methane yield during anaerobic digestion. The experimental results were used to establish a demonstration unit consisting of a 100 L composter, a 200 L anaerobic digester, a 60 L tubular photobioreactor, and a 300 L micro-open raceway pond.

High purith low defect FZ silicon

NASA Technical Reports Server (NTRS)

Kimura, H.; Robertson, G.

1985-01-01

The most common intrinsic defects in dislocation-free float zone (FZ) silicon crystals are the A- and B-type swirl defects. The mechanisms of their formation and annihilation have been extensively studied. Another type of defect in dislocation-free FZ crystals is referred to as a D-type defect. Concentrations of these defects can be minimized by optimizing the growth conditions, and the residual swirls can be reduced by the post-growth extrinsic gettering process. Czochralski (Cz) silicon wafers are known to exhibit higher resistance to slip and warpage due to thermal stress than do FZ wafers. The Cz crystals containing dislocations are more resistant to dislocation movement than dislocated FZ crystals because of the locking of dislocations by oxygen atoms present in the Cz crystals. Recently a transverse magnetic field was applied during the FZ growth of extrinsic silicon. Resultant flow patterns, as revealed by striation etching and spreading resistance in Ga-doped silicon crystals, indicate strong effects of the transverse magnetic field on the circulation within the melt. At fields of 5500 gauss, the fluid flow in the melt volume is so altered as to affect the morphology of the growing crystal.

[Roseibacula alcaliphilum gen. nov. sp. nov., a new alkaliphilic aerobic anoxygenic phototrophic bacterium from a meromictic soda Lake Doroninskoe (East Siberia, Russia)].

PubMed

Nuianzina-Boldareva, E N; Gorlenko, V M

2014-01-01

A bacterial strain De was isolated from the surface water layer of the meromictic soda lake Doroninskoe. When grown in the dark, it formed-pink colonies on agar media. The cells were nonmotile, contained bacteriochlorophyll a and carotenoids. Stationary-phase cells contained intracellular vesicular membranes similar to the membranes of the photosynthetic apparatus of some ndnsulfur purple bacteria. Aerobic growth did not occur. Sucrose, citrate, mannitol, sorbitol, case in hydrolysate,and yeast extract were the preferable substrates for aerobic growth, Xylose, lactose, aspartate, benzoate, malate, malonate, succinate, tartrate, formate, fumarate, glycerol, methanol, and ethanol were not utilized; Growth occurred at up to 50.g/L NaCl (optimum at 5 g/L) and pH 9.8. According to the 16S rRNA gene sequencing, similarity between the isolate and the known alkaliphilic genera of nonsulfur purple bacteria (Rhodobaca) and of aerobic anoxygenic phototrophic bacteria (Roseinatronobacter) was 96%, which was sufficient for description ofa new genus of aerobic anoxygenic phototrophic bacteria. The name Roseibacula alcaliphiluin gen. nov., sp. nov. was, proposed for the isolate.

Enteric bacteria in aerobically digested sludge.

PubMed Central

Farrah, S R; Bitton, G

1984-01-01

Indicator bacteria, Salmonella spp., and total aerobic bacteria were determined in samples of undigested sludge and sludge that had been treated by one or two stages of aerobic digestion. Aerobic sludge digestion reduced the level of indicator bacteria by 1 to 2 log10 per g. The level of Salmonella spp. was also reduced during aerobic treatment of sludge. In general, aerobic treatment of sludge reduced, but did not eliminate, indicator bacteria and Salmonella spp. PMID:6721492

Regenerative effect of basic fibroblast growth factor on periodontal healing in two-wall intrabony defects in dogs.

PubMed

Shirakata, Yoshinori; Taniyama, Katsuyoshi; Yoshimoto, Takehiko; Miyamoto, Motoharu; Takeuchi, Naoshi; Matsuyama, Takashi; Noguchi, Kazuyuki

2010-04-01

The aim of the present study was to evaluate the effect of a basic fibroblast growth factor (bFGF) candidate treatment on periodontal healing in two-wall intrabony defects in dogs. Two-wall intrabony defects (5 x 5 x 5 mm) were created surgically on the distal and mesial sides of bilateral mandibular second and fourth premolars in four Beagle dogs. bFGF, enamel matrix derivative (EMD) and platelet-derived growth factor with beta-tricalcium phosphate (PDGF/beta-TCP) treatments, and sham-surgery (OFD) were rotated among the four defects in each animal, EMD and PDGF/beta-TCP serving as benchmark controls. The animals were euthanized for radiographic and histologic evaluation at 8 weeks. Bone formation was significantly greater in the bFGF group (4.11 +/- 0.77 mm) than in the EMD (3.32 +/- 0.71 mm; p<0.05) and OFD (3.09 +/- 0.52 mm; p<0.01) groups. The EMD (4.59 +/- 1.19 mm) and PDGF/beta-TCP (4.66 +/- 0.7 mm) groups exhibited significantly greater cementum regeneration with periodontal ligament-like tissue than the OFD group (2.96 +/- 0.69 mm; p<0.01). No significant differences were observed between the bFGF and the PDGF/beta-TCP groups in any of the histometric parameters. The candidate bFGF treatment supported periodontal regeneration comparable with that of established benchmarks: EMD and PDGF/beta-TCP.

False no-growth blood cultures in pneumococcal pneumonia.

PubMed Central

Adeniyi-Jones, C C; Stevens, D L; Rasquinha, E S

1980-01-01

The growth of Streptococcus pneumoniae in commercial media containing 14C-labeled substrates was studied experimentally; the results of blood cultures that were positive for S. pneumoniae over a 14-month period were analyzed to explain no-growth but radiometrically positive blood cultures from four patients with clinically diagnosed pneumococcal pneumonia. The growth of S. pneumonoiae in aerobic blood culture vials resulted in a chocolate color in the medium. S. pneumoniae grew rapidly in both aerobic and anaerobic media, but 14CO2 evolved from the metabolism of the labeled substrates was detected only in the aerobic culture vials. Radiometric detection lagged behind growth of the organisms and was accompanied by visual changes in the media. By 24 h, the viability of the culture was on the decline; radiometric readings remained positive even when the culture had died. PMID:7419708

Aerobic conditioning for team sport athletes.

PubMed

Stone, Nicholas M; Kilding, Andrew E

2009-01-01

Team sport athletes require a high level of aerobic fitness in order to generate and maintain power output during repeated high-intensity efforts and to recover. Research to date suggests that these components can be increased by regularly performing aerobic conditioning. Traditional aerobic conditioning, with minimal changes of direction and no skill component, has been demonstrated to effectively increase aerobic function within a 4- to 10-week period in team sport players. More importantly, traditional aerobic conditioning methods have been shown to increase team sport performance substantially. Many team sports require the upkeep of both aerobic fitness and sport-specific skills during a lengthy competitive season. Classic team sport trainings have been shown to evoke marginal increases/decreases in aerobic fitness. In recent years, aerobic conditioning methods have been designed to allow adequate intensities to be achieved to induce improvements in aerobic fitness whilst incorporating movement-specific and skill-specific tasks, e.g. small-sided games and dribbling circuits. Such 'sport-specific' conditioning methods have been demonstrated to promote increases in aerobic fitness, though careful consideration of player skill levels, current fitness, player numbers, field dimensions, game rules and availability of player encouragement is required. Whilst different conditioning methods appear equivalent in their ability to improve fitness, whether sport-specific conditioning is superior to other methods at improving actual game performance statistics requires further research.

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. Copyright © 2015 Elsevier Inc. All rights reserved.

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)

Longitudinal analysis of head and somatic growth in fetuses with congenital heart defects.

PubMed

Turan, Sifa; Rosenbloom, Joshua I; Hussein, Mostafa; Berg, Christoph; Gembruch, Ulrich; Baschat, Ahmet A; Turan, Ozhan M

2017-02-01

Fetal head and somatic growth dynamics differs in fetuses with congenital heart defects (CHD). We longitudinally characterized fetal head and somatic growth in relation to the type of CHD. Four hundred eleven exams from isolated CHD were compared with 1,219 controls. Head and somatic growth was assessed using head circumference (HC), brain volume (BrV = 1/6 × π × (HC/π)3)/2), fetal cephalization index (FCI = BrV/[estimated fetal weight]), and growth percentile. Umbilical and middle cerebral artery Doppler indices were obtained. CHD were grouped as: (1) d-transposition of great arteries (n = 11); (2) left ventricular outflow tract obstruction with retrograde isthmic flow (n = 18); (3) left ventricular outflow tract obstruction with antegrade isthmic flow (n = 16); (4) pulmonary outflow tract obstructions (n = 22). The smallest head size was seen in group 1. Growth asymmetry was diagnosed in group 2. Brain sparing was seen in groups 2 and 4 (p < 0.0001). HC and BrV percentiles decreased with advancing gestational age (p < 0.001) in group 2, and a significant drop was observed around 28 weeks. d-Transposition of great arteries and left-sided CHD leading to isthmic blood flow reversal are associated with delayed head growth. Prenatal evaluation of central hemodynamics in CHD may be contributive for predicting neurodevelopmental risks in CHD and help directing prenatal interventions. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 45:96-104, 2017. © 2016 Wiley Periodicals, Inc.

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.

Growth of left ventricular outflow tract and predictors of future re-intervention after repair for ventricular septal defect and aortic arch obstruction.

PubMed

Jijeh, Abdulraouf; Ismail, Muna; Alhabshan, Fahad

2017-09-01

Ventricular septal defect and aortic arch obstruction are usually associated with a narrow left ventricular outflow tract. The aim of the present study was to analyse the growth and predictors of future obstruction of the left ventricular outflow tract after surgical repair. We carried out a retrospective review of patients who underwent repair for ventricular septal defect and aortic arch obstruction - coarctation or interrupted aortic arch - between July, 2002 and June, 2013. Echocardiographic data were reviewed, and the need for re-intervention was evaluated. A total of 89 patients were included in this study. A significant left ventricular outflow tract growth was noticed after surgical repair. Preoperatively, the mean left ventricular outflow tract Z-score was -1.46±1 (range -5.5 to 1.1) and increased to a mean value of -0.7±1.3 (range -2.7 to 3.2) at last follow-up (p=0.0001), demonstrating relevant growth of the left ventricular outflow tract after repair for ventricular septal defect and aortic arch obstruction. After primary repair, 11 patients (12.3%) required re-intervention with surgical repair for left ventricular outflow tract obstruction after a mean period of 36±21 months. There were no significant differences in age, weight, and indexed aortic valve and left ventricular outflow tract measurements between those who developed obstruction and those who did not. Significant left ventricular outflow tract growth is expected after repair of ventricular septal defect and aortic arch obstruction. Small aortic valve and left ventricular outflow tract at diagnosis are not risk factors to predict the need for surgical re-intervention for left ventricular outflow tract obstruction in future.

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)

The use of aerobic exercise training in improving aerobic capacity in individuals with stroke: a meta-analysis

PubMed Central

Pang, Marco YC; Eng, Janice J; Dawson, Andrew S; Gylfadóttir, Sif

2011-01-01

Objective To determine whether aerobic exercise improves aerobic capacity in individuals with stroke. Design A systematic review of randomized controlled trials. Databases searched MEDLINE, CINAHL, EMBASE, Cochrane Database of Systematic Reviews, Physiotherapy Evidence Database were searched. Inclusion criteria Design: randomized controlled trials; Participants: individuals with stroke; Interventions: aerobic exercise training aimed at improving aerobic capacity; Outcomes Primary outcomes: aerobic capacity [peak oxygen consumption (VO2), peak workload); Secondary outcomes: walking velocity, walking endurance. Data Analysis The methodological quality was assessed by the PEDro scale. Meta-analyses were performed for all primary and secondary outcomes. Results Nine articles (seven RCTs) were identified. The exercise intensity ranged from 50% to 80% heart rate reserve. Exercise duration was 20–40 minutes for 3–5 days a week. The total number of subjects included in the studies was 480. All studies reported positive effects on aerobic capacity, regardless of the stage of stroke recovery. Meta-analysis revealed a significant homogeneous standardized effect size (SES) in favour of aerobic exercise to improve peak VO2 (SES, 0.42; 95%CI, 0.15 to 0.69; p=0.001) and peak workload (SES, 0.50; 95%CI, 0.26 to 0.73; p<0.001). There was also a significant homogeneous SES in favour of aerobic training to improve walking velocity (SES, 0.26; 95%CI, 0.05 to 0.48; p=0.008) and walking endurance (SES, 0.30; 95%CI, 0.06to 0.55; p=0.008). Conclusions There is good evidence that aerobic exercise is beneficial for improving aerobic capacity in people with mild and moderate stroke. Aerobic exercise should be an important component of stroke rehabilitation. PMID:16541930

Enhanced performance of denitrifying sulfide removal process at high carbon to nitrogen ratios under micro-aerobic condition.

PubMed

Chen, Chuan; Zhang, Ruo-Chen; Xu, Xi-Jun; Fang, Ning; Wang, Ai-Jie; Ren, Nan-Qi; Lee, Duu-Jong

2017-05-01

The success of denitrifying sulfide removal (DSR) processes, which simultaneously degrade sulfide, nitrate and organic carbon in the same reactor, counts on synergetic growths of autotrophic and heterotrophic denitrifiers. Feeding wastewaters at high C/N ratio would stimulate overgrowth of heterotrophic bacteria in the DSR reactor so deteriorating the growth of autotrophic denitrifiers. The DSR tests at C/N=1.26:1, 2:1 or 3:1 and S/N =5:6 or 5:8 under anaerobic (control) or micro-aerobic conditions were conducted. Anaerobic DSR process has <50% sulfide removal with no elemental sulfur transformation. Under micro-aerobic condition to remove <5% sulfide by chemical oxidation pathway, 100% sulfide removal is achieved by the DSR consortia. Continuous-flow tests under micro-aerobic condition have 70% sulfide removal and 55% elemental sulfur recovery. Trace oxygen enhances activity of sulfide-oxidizing, nitrate-reducing bacteria to accommodate properly the wastewater with high C/N ratios. Copyright © 2017 Elsevier Ltd. All rights reserved.

Short-term water-based aerobic training promotes improvements in aerobic conditioning parameters of mature women.

PubMed

Costa, Rochelle Rocha; Reichert, Thais; Coconcelli, Leandro; Simmer, Nicole Monticelli; Bagatini, Natália Carvalho; Buttelli, Adriana Cristine Koch; Bracht, Cláudia Gomes; Stein, Ricardo; Kruel, Luiz Fernando Martins

2017-08-01

Aging is accompanied by a decrease in aerobic capacity. Therefore, physical training has been recommended to soften the effects of advancement age. The aim of this study was to assess the effects of a short-term water-based aerobic training on resting heart rate (HR rest ), heart rate corresponding to anaerobic threshold (HR AT ), peak heart rate (HR peak ), percentage value of HR AT in relation to HR peak and test duration (TD) of mature women. Twenty-two women (65.91 ± 4.83 years) were submitted to a five-week water-based interval aerobic training. Aerobic capacity parameters were evaluated through an aquatic incremental test. After training, there was an increase in TD (16%) and HR AT percentage in relation to HR peak (4.68%), and a reduction of HR rest (9%). It is concluded that a water-based aerobic interval training prescribed through HR AT of only five weeks is able to promote improvements in aerobic capacity of mature women. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

USDA-ARS?s Scientific Manuscript database

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...

Characteristics and performance of aerobic algae-bacteria granular consortia in a photo-sequencing batch reactor.

PubMed

Liu, Lin; Zeng, Zhichao; Bee, Mingyang; Gibson, Valerie; Wei, Lili; Huang, Xu; Liu, Chaoxiang

2018-05-05

The characteristics and performance of algae-bacteria granular consortia which cultivated with aerobic granules and targeted algae (Chlorella and Scenedesmus), and the essential difference between granular consortia and aerobic granules were investigated in this experiment. The result indicated that algae-bacteria granular consortia could be successfully developed, and the algae present in the granular consortia were mainly Chlorella and Scenedesmus. Although the change of chlorophyll composition revealed the occurrence of light limitation for algal growth, the granular consortia could maintain stable granular structure, and even showed better settling property than aerobic granules. Total nitrogen and phosphate in the algal-bacterial granular system showed better removal efficiencies (50.2% and 35.7%) than those in the aerobic granular system (32.8% and 25.6%) within one cycle (6 h). The biodiesel yield of aerobic granules could be significantly improved by algal coupled process, yet methyl linolenate and methyl palmitoleate were the dominant composition of biodiesel obtained from granular consortia and aerobic granules, respectively. Meanwhile, the difference of dominant bacterial communities in the both granules was found at the order level and family level, and alpha diversity indexes revealed the granular consortia had a higher microbial diversity. Copyright © 2018. Published by Elsevier B.V.

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. © 2016 Institute of Food Technologists®

[Phosphate-solubilizing activity of aerobic methylobacteria].

PubMed

Agafonova, N V; Kaparullina, E N; Doronina, N V; Trotsenko, Iu A

2014-01-01

Phosphate-solubilizing activity was found in 14 strains of plant-associated aerobic methylobacteria belonging to the genera Methylophilus, Methylobacillus, Methylovorus, Methylopila, Methylobacterium, Delftia, and Ancyclobacter. The growth of methylobacteria on medium with methanol as the carbon and energy source and insoluble tricalcium phosphate as the phosphorus source was accompanied by a decrease in pH due to the accumulation of up to 7 mM formic acid as a methanol oxidation intermediate and by release of 120-280 μM phosphate ions, which can be used by both bacteria and plants. Phosphate-solubilizing activity is a newly revealed role of methylobacteria in phytosymbiosis.

An Mcm10 Mutant Defective in ssDNA Binding Shows Defects in DNA Replication Initiation.

PubMed

Perez-Arnaiz, Patricia; Kaplan, Daniel L

2016-11-20

Mcm10 is an essential protein that functions to initiate DNA replication after the formation of the replication fork helicase. In this manuscript, we identified a budding yeast Mcm10 mutant (Mcm10-m2,3,4) that is defective in DNA binding in vitro. Moreover, this Mcm10-m2,3,4 mutant does not stimulate the phosphorylation of Mcm2 by Dbf4-dependent kinase (DDK) in vitro. When we expressed wild-type levels of mcm10-m2,3,4 in budding yeast cells, we observed a severe growth defect and a substantially decreased DNA replication. We also observed a substantially reduced replication protein A- chromatin immunoprecipitation signal at origins of replication, reduced levels of DDK-phosphorylated Mcm2, and diminished Go, Ichi, Ni, and San (GINS) association with Mcm2-7 in vivo. mcm5-bob1 bypasses the growth defect conferred by DDK-phosphodead Mcm2 in budding yeast. However, the growth defect observed by expressing mcm10-m2,3,4 is not bypassed by the mcm5-bob1 mutation. Furthermore, origin melting and GINS association with Mcm2-7 are substantially decreased for cells expressing mcm10-m2,3,4 in the mcm5-bob1 background. Thus, the origin melting and GINS-Mcm2-7 interaction defects we observed for mcm10-m2,3,4 are not explained by decreased Mcm2 phosphorylation by DDK, since the defects persist in an mcm5-bob1 background. These data suggest that DNA binding by Mcm10 is essential for the initiation of DNA replication. Copyright © 2016 Elsevier Ltd. All rights reserved.

On aerobic exercise and behavioral and neural plasticity.

PubMed

Swain, Rodney A; Berggren, Kiersten L; Kerr, Abigail L; Patel, Ami; Peplinski, Caitlin; Sikorski, Angela M

2012-11-29

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.

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

Does Aerobic Exercise Influence Intrinsic Brain Activity? An Aerobic Exercise Intervention among Healthy Old Adults

PubMed Central

Flodin, Pär; Jonasson, Lars S.; Riklund, Katrin; Nyberg, Lars; Boraxbekk, C. J.

2017-01-01

Previous studies have indicated that aerobic exercise could reduce age related decline in cognition and brain functioning. Here we investigated the effects of aerobic exercise on intrinsic brain activity. Sixty sedentary healthy males and females (64–78 years) were randomized into either an aerobic exercise group or an active control group. Both groups recieved supervised training, 3 days a week for 6 months. Multimodal brain imaging data was acquired before and after the intervention, including 10 min of resting state brain functional magnetic resonance imaging (rs-fMRI) and arterial spin labeling (ASL). Additionally, a comprehensive battery of cognitive tasks assessing, e.g., executive function and episodic memory was administered. Both the aerobic and the control group improved in aerobic capacity (VO2-peak) over 6 months, but a significant group by time interaction confirmed that the aerobic group improved more. Contrary to our hypothesis, we did not observe any significant group by time interactions with regard to any measure of intrinsic activity. To further probe putative relationships between fitness and brain activity, we performed post hoc analyses disregarding group belongings. At baseline, VO2-peak was negativly related to BOLD-signal fluctuations (BOLDSTD) in mid temporal areas. Over 6 months, improvements in aerobic capacity were associated with decreased connectivity between left hippocampus and contralateral precentral gyrus, and positively to connectivity between right mid-temporal areas and frontal and parietal regions. Independent component analysis identified a VO2-related increase in coupling between the default mode network and left orbitofrontal cortex, as well as a decreased connectivity between the sensorimotor network and thalamus. Extensive exploratory data analyses of global efficiency, connectome wide multivariate pattern analysis (connectome-MVPA), as well as ASL, did not reveal any relationships between aerobic fitness and intrinsic

Does Aerobic Exercise Influence Intrinsic Brain Activity? An Aerobic Exercise Intervention among Healthy Old Adults.

PubMed

Flodin, Pär; Jonasson, Lars S; Riklund, Katrin; Nyberg, Lars; Boraxbekk, C J

2017-01-01

Previous studies have indicated that aerobic exercise could reduce age related decline in cognition and brain functioning. Here we investigated the effects of aerobic exercise on intrinsic brain activity. Sixty sedentary healthy males and females (64-78 years) were randomized into either an aerobic exercise group or an active control group. Both groups recieved supervised training, 3 days a week for 6 months. Multimodal brain imaging data was acquired before and after the intervention, including 10 min of resting state brain functional magnetic resonance imaging (rs-fMRI) and arterial spin labeling (ASL). Additionally, a comprehensive battery of cognitive tasks assessing, e.g., executive function and episodic memory was administered. Both the aerobic and the control group improved in aerobic capacity (VO 2 -peak) over 6 months, but a significant group by time interaction confirmed that the aerobic group improved more. Contrary to our hypothesis, we did not observe any significant group by time interactions with regard to any measure of intrinsic activity. To further probe putative relationships between fitness and brain activity, we performed post hoc analyses disregarding group belongings. At baseline, VO 2 -peak was negativly related to BOLD-signal fluctuations (BOLD STD ) in mid temporal areas. Over 6 months, improvements in aerobic capacity were associated with decreased connectivity between left hippocampus and contralateral precentral gyrus, and positively to connectivity between right mid-temporal areas and frontal and parietal regions. Independent component analysis identified a VO 2 -related increase in coupling between the default mode network and left orbitofrontal cortex, as well as a decreased connectivity between the sensorimotor network and thalamus. Extensive exploratory data analyses of global efficiency, connectome wide multivariate pattern analysis (connectome-MVPA), as well as ASL, did not reveal any relationships between aerobic fitness and

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). Copyright © 2014 Elsevier Ltd. All rights reserved.

Guided Bone Regeneration Using Collagen Scaffolds, Growth Factors, and Periodontal Ligament Stem Cells for Treatment of Peri-Implant Bone Defects In Vivo.

PubMed

Kämmerer, Peer W; Scholz, Malte; Baudisch, Maria; Liese, Jan; Wegner, Katharina; Frerich, Bernhard; Lang, Hermann

2017-01-01

The aim of the study was an evaluation of different approaches for guided bone regeneration (GBR) of peri-implant defects in an in vivo animal model. In minipigs ( n = 15), peri-implant defects around calcium phosphate- (CaP-; n = 46) coated implants were created and randomly filled with (1) blank, (2) collagen/hydroxylapatite/ β -tricalcium phosphate scaffold (CHT), (3) CHT + growth factor cocktail (GFC), (4) jellyfish collagen matrix, (5) jellyfish collagen matrix + GFC, (6) collagen powder, and (7) collagen powder + periodontal ligament stem cells (PDLSC). Additional collagen membranes were used for coverage of the defects. After 120 days of healing, bone growth was evaluated histologically (bone to implant contact (BIC;%)), vertical bone apposition (VBA; mm), and new bone height (NBH; %). In all groups, new bone formation was seen. Though, when compared to the blank group, no significant differences were detected for all parameters. BIC and NBH in the group with collagen matrix as well as the group with the collagen matrix + GFC were significantly less when compared to the collagen powder group (all: p < 0.003). GBR procedures, in combination with CaP-coated implants, will lead to an enhancement of peri-implant bone growth. There was no additional significant enhancement of osseous regeneration when using GFC or PDLSC.

Adaptation to Aerobic Environment of Lactobacillus johnsonii/gasseri Strains

PubMed Central

Maresca, Diamante; Zotta, Teresa; Mauriello, Gianluigi

2018-01-01

Oxygen is considered one of the main factors affecting probiotic bacteria survival due to the induction of oxidative damages caused by the action of reactive oxygen species (ROS). It has been shown that oxidative stress resistance in lactic acid bacteria is strongly dependent on the type of cell metabolism. Shift from fermentative to respiratory metabolism (through the addition of heme and menaquinone and in presence of oxygen) was associated to increase in biomass, long-term survival, and production of antioxidant enzymes. The aim of this work was to investigate the effect of aerobic (presence of oxygen) and respiratory (presence of oxygen, heme, and menaquinone) cultivation on the growth kinetic, catalase production, oxygen uptake, and oxidative stress response of Lactobacillus johnsonii/gasseri strains previously isolated from infant feces. Seven strains showed to consume oxygen under aerobic and respiratory conditions. The strain AL5 showed a catalase activity in both growth conditions, while AL3 showed this activity only in respiratory condition. Respiratory condition improved their tolerance to oxidative compounds (hydrogen peroxide and ROS generators) and further they showed promising probiotic features. The exploration of respiratory competent phenotypes with probiotic features may be extremely useful for the development of competitive starter or probiotic cultures. PMID:29479342

Adaptation to Aerobic Environment of Lactobacillus johnsonii/gasseri Strains.

PubMed

Maresca, Diamante; Zotta, Teresa; Mauriello, Gianluigi

2018-01-01

Oxygen is considered one of the main factors affecting probiotic bacteria survival due to the induction of oxidative damages caused by the action of reactive oxygen species (ROS). It has been shown that oxidative stress resistance in lactic acid bacteria is strongly dependent on the type of cell metabolism. Shift from fermentative to respiratory metabolism (through the addition of heme and menaquinone and in presence of oxygen) was associated to increase in biomass, long-term survival, and production of antioxidant enzymes. The aim of this work was to investigate the effect of aerobic (presence of oxygen) and respiratory (presence of oxygen, heme, and menaquinone) cultivation on the growth kinetic, catalase production, oxygen uptake, and oxidative stress response of Lactobacillus johnsonii/gasseri strains previously isolated from infant feces. Seven strains showed to consume oxygen under aerobic and respiratory conditions. The strain AL5 showed a catalase activity in both growth conditions, while AL3 showed this activity only in respiratory condition. Respiratory condition improved their tolerance to oxidative compounds (hydrogen peroxide and ROS generators) and further they showed promising probiotic features. The exploration of respiratory competent phenotypes with probiotic features may be extremely useful for the development of competitive starter or probiotic cultures.

Arabidopsis thaliana cdd1 mutant uncouples the constitutive activation of salicylic acid signalling from growth defects.

PubMed

Swain, Swadhin; Roy, Shweta; Shah, Jyoti; Van Wees, Saskia; Pieterse, Corné M; Nandi, Ashis K

2011-12-01

Arabidopsis genotypes with a hyperactive salicylic acid-mediated signalling pathway exhibit enhanced disease resistance, which is often coupled with growth and developmental defects, such as dwarfing and spontaneous necrotic lesions on the leaves, resulting in reduced biomass yield. In this article, we report a novel recessive mutant of Arabidopsis, cdd1 (constitutive defence without defect in growth and development1), that exhibits enhanced disease resistance associated with constitutive salicylic acid signalling, but without any observable pleiotropic phenotype. Both NPR1 (NON-EXPRESSOR OF PATHOGENESIS-RELATED GENES1)-dependent and NPR1-independent salicylic acid-regulated defence pathways are hyperactivated in cdd1 mutant plants, conferring enhanced resistance against bacterial pathogens. However, a functional NPR1 allele is required for the cdd1-conferred heightened resistance against the oomycete pathogen Hyaloperonospora arabidopsidis. Salicylic acid accumulates at elevated levels in cdd1 and cdd1 npr1 mutant plants and is necessary for cdd1-mediated PR1 expression and disease resistance phenotypes. In addition, we provide data which indicate that the cdd1 mutation negatively regulates the npr1 mutation-induced hyperactivation of ethylene/jasmonic acid signalling. © 2011 The Authors. Molecular Plant Pathology © 2011 BSPP and Blackwell Publishing Ltd.

Identification of target genes to control acetate yield during aerobic fermentation with Saccharomyces cerevisiae.

PubMed

Curiel, José Antonio; Salvadó, Zoel; Tronchoni, Jordi; Morales, Pilar; Rodrigues, Alda Joao; Quirós, Manuel; Gonzalez, Ramón

2016-09-15

Aerobic fermentation of grape must, leading to respiro-fermentative metabolism of sugars, has been proposed as way of reducing alcohol content in wines. Two factors limit the usefulness of Saccharomyces cerevisiae for this application, the Crabtree effect, and excess volatile acidity under aerobic conditions. This work aimed to explore the impact on ethanol acetate production of different S. cerevisiae strains deleted for genes previously related with the Crabtree phenotype. Recombinant strains were constructed on a wine industrial genetic background, FX10. All yeast strains, including FX10, showed respiro-fermentative metabolism in natural grape must under aerobic conditions, as well as a concomitant reduction in ethanol yield. This indicates that the Crabtree effect is not a major constrain for reaching relevant respiration levels in grape must. Indeed, only minor differences in ethanol yield were observed between the original and some of the recombinant strains. In contrast, some yeast strains showed a relevant reduction of acetic acid production. This was identified as a positive feature for the feasibility of alcohol level reduction by respiration. Reduced acetic acid production was confirmed by a thorough analysis of these and some additional deletion strains (involving genes HXK2, PYK1, REG1, PDE2 and PDC1). Some recombinant yeasts showed altered production of glycerol and pyruvate derived metabolites. REG1 and PDC1 deletion strains showed a strong reduction of acetic acid yield in aerobic fermentations. Since REG1 defective strains may be obtained by non-GMO approaches, these gene modifications show good promise to help reducing ethanol content in wines.

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…

Role of topographical defects in organic film growth of 4,4' -biphenyldicarboxylic acid on graphene: A low-energy electron microscopy study

NASA Astrophysics Data System (ADS)

Khokhar, Fawad S.; van Gastel, Raoul; Poelsema, Bene

2010-11-01

We have used low-energy electron microscopy (LEEM) to study the formation of self-assembled molecular networks on graphene sheets. 4,4' -biphenyldicarboxylic acid (BDA) molecular networks were grown using organic molecular beam epitaxy. LEEM images provide direct insight in the growth dynamics and show that defects in the graphene play a crucial role in the final morphology of the molecular film that forms. BDA is demonstrated to form hydrogen bond-stabilized chains on graphene. Dark-field LEEM images reveal that the same defects that determine the morphology of the film, also direct the orientation of the domains, highlighting the importance of understanding the role of defects in epitaxial processes on graphene.

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. Copyright © 2015

Molecular defects of the growth hormone receptor gene, including a new mutation, in Laron syndrome patients in Israel: relationship between defects and ethnic groups.

PubMed

Shevah, Orit; Rubinstein, Menachem; Laron, Zvi

2004-10-01

Laron Syndrome, first described in Israel, is a form of dwarfism similar to isolated growth hormone deficiency caused by molecular defects in the GH receptor gene. To characterize the molecular defects of the GH-R in Laron syndrome patients followed in our clinic. Of the 63 patients in the cohort, we investigated 31 patients and 32 relatives belonging to several ethnic origins. Molecular analysis of the GH-R gene was performed using the single strand conformation polymorphism and DNA sequencing techniques. Eleven molecular defects including a novel mutation were found. Twenty-two patients carried mutations in the extracellular domain, one in the transmembrane domain, and 3 siblings with typical Laron syndrome presented a normal GH-R. Of interest are, on one hand, different mutations within the same ethnic groups: W-15X and 5, 6 exon deletion in Jewish-Iraqis, and E180 splice and 5, 6 exon deletion in Jewish-Moroccans; and on the other hand, identical findings in patients from distinct regions: the 785-1 G to T mutation in an Israeli-Druze and a Peruvian patient. A polymorphism in exon 6, Gly168Gly, was found in 15 probands. One typical Laron patient from Greece was heterozygous for R43X in exon 4 and heterozygous for Gly168Gly. In addition, a novel mutation in exon 5: substitution of T to G replacing tyrosine 86 for aspartic acid (Y86D) is described. This study demonstrates: a) an increased focal incidence of Laron syndrome in different ethnic groups from our area with a high incidence of consanguinity; and b) a relationship between molecular defects of the GH-R, ethnic group and geographic area.

[Progress of Masquelet technique to repair bone defect].

PubMed

Yin, Qudong; Sun, Zhenzhong; Gu, Sanjun

2013-10-01

To summarize the progress of Masquelet technique to repair bone defect. The recent literature concerning the application of Masquelet technique to repair bone defect was extensively reviewed and summarized. Masquelet technique involves a two-step procedure. First, bone cement is used to fill the bone defect after a thorough debridement, and an induced membrane structure surrounding the spacer formed; then the bone cement is removed after 6-8 weeks, and rich cancellous bone is implanted into the induced membrane. Massive cortical bone defect is repaired by new bone forming and consolidation. Experiments show that the induced membrane has vascular system and is also rich in vascular endothelial growth factor, transforming growth factor beta1, bone morphogenetic protein 2, and bone progenitor cells, so it has osteoinductive property; satisfactory results have been achieved in clinical application of almost all parts of defects, various types of bone defect and massive defect up to 25 cm long. Compared with other repair methods, Masquelet technique has the advantages of reliable effect, easy to operate, few complications, low requirements for recipient site, and wide application. Masquelet technique is an effective method to repair bone defect and is suitable for various types of bone defect, especially for bone defects caused by infection and tumor resection.

Loss of PopZAt activity in Agrobacterium tumefaciens by Deletion or Depletion Leads to Multiple Growth Poles, Minicells, and Growth Defects

PubMed Central

Grangeon, Romain; Zupan, John; Jeon, Yeonji

2017-01-01

ABSTRACT Agrobacterium tumefaciens grows by addition of peptidoglycan (PG) at one pole of the bacterium. During the cell cycle, the cell needs to maintain two different developmental programs, one at the growth pole and another at the inert old pole. Proteins involved in this process are not yet well characterized. To further characterize the role of pole-organizing protein A. tumefaciens PopZ (PopZAt), we created deletions of the five PopZAt domains and assayed their localization. In addition, we created a popZAt deletion strain (ΔpopZAt) that exhibited growth and cell division defects with ectopic growth poles and minicells, but the strain is unstable. To overcome the genetic instability, we created an inducible PopZAt strain by replacing the native ribosome binding site with a riboswitch. Cultivated in a medium without the inducer theophylline, the cells look like ΔpopZAt cells, with a branching and minicell phenotype. Adding theophylline restores the wild-type (WT) cell shape. Localization experiments in the depleted strain showed that the domain enriched in proline, aspartate, and glutamate likely functions in growth pole targeting. Helical domains H3 and H4 together also mediate polar localization, but only in the presence of the WT protein, suggesting that the H3 and H4 domains multimerize with WT PopZAt, to stabilize growth pole accumulation of PopZAt. PMID:29138309

Field assessment of semi-aerobic condition and the methane correction factor for the semi-aerobic landfills provided by IPCC guidelines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jeong, Sangjae; Nam, Anwoo; Yi, Seung-Muk

Highlights: • CH{sub 4}/CO{sub 2} and CH{sub 4} + CO{sub 2}% are proposed as indices to evaluate semi-aerobic landfills. • A landfill which CH{sub 4}/CO{sub 2} > 1.0 is difficult to be categorized as semi-aerobic landfill. • Field conditions should be carefully investigated to determine landfill types. • The MCF default value for semi-aerobic landfills underestimates the methane emissions. - Abstract: According to IPCC guidelines, a semi-aerobic landfill site produces one-half of the amount of CH{sub 4} produced by an equally-sized anaerobic landfill site. Therefore categorizing the landfill type is important on greenhouse gas inventories. In order to assess semi-aerobicmore » condition in the sites and the MCF value for semi-aerobic landfill, landfill gas has been measured from vent pipes in five semi-aerobically designed landfills in South Korea. All of the five sites satisfied requirements of semi-aerobic landfills in 2006 IPCC guidelines. However, the ends of leachate collection pipes which are main entrance of air in the semi-aerobic landfill were closed in all five sites. The CH{sub 4}/CO{sub 2} ratio in landfill gas, indicator of aerobic and anaerobic decomposition, ranged from 1.08 to 1.46 which is higher than the values (0.3–1.0) reported for semi-aerobic landfill sites and is rather close to those (1.0–2.0) for anaerobic landfill sites. The low CH{sub 4} + CO{sub 2}% in landfill gas implied air intrusion into the landfill. However, there was no evidence that air intrusion has caused by semi-aerobic design and operation. Therefore, the landfills investigated in this study are difficult to be classified as semi-aerobic landfills. Also MCF of 0.5 may significantly underestimate methane emissions compared to other researches. According to the carbon mass balance analyses, the higher MCF needs to be proposed for semi-aerobic landfills. Consequently, methane emission estimate should be based on field evaluation for the semi-aerobically designed

Field assessment of semi-aerobic condition and the methane correction factor for the semi-aerobic landfills provided by IPCC guidelines.

PubMed

Jeong, Sangjae; Nam, Anwoo; Yi, Seung-Muk; Kim, Jae Young

2015-02-01

According to IPCC guidelines, a semi-aerobic landfill site produces one-half of the amount of CH4 produced by an equally-sized anaerobic landfill site. Therefore categorizing the landfill type is important on greenhouse gas inventories. In order to assess semi-aerobic condition in the sites and the MCF value for semi-aerobic landfill, landfill gas has been measured from vent pipes in five semi-aerobically designed landfills in South Korea. All of the five sites satisfied requirements of semi-aerobic landfills in 2006 IPCC guidelines. However, the ends of leachate collection pipes which are main entrance of air in the semi-aerobic landfill were closed in all five sites. The CH4/CO2 ratio in landfill gas, indicator of aerobic and anaerobic decomposition, ranged from 1.08 to 1.46 which is higher than the values (0.3-1.0) reported for semi-aerobic landfill sites and is rather close to those (1.0-2.0) for anaerobic landfill sites. The low CH4+CO2% in landfill gas implied air intrusion into the landfill. However, there was no evidence that air intrusion has caused by semi-aerobic design and operation. Therefore, the landfills investigated in this study are difficult to be classified as semi-aerobic landfills. Also MCF of 0.5 may significantly underestimate methane emissions compared to other researches. According to the carbon mass balance analyses, the higher MCF needs to be proposed for semi-aerobic landfills. Consequently, methane emission estimate should be based on field evaluation for the semi-aerobically designed landfills. Copyright © 2015. Published by Elsevier Ltd.

Guided Bone Regeneration Using Collagen Scaffolds, Growth Factors, and Periodontal Ligament Stem Cells for Treatment of Peri-Implant Bone Defects In Vivo

PubMed Central

Scholz, Malte; Baudisch, Maria; Liese, Jan; Frerich, Bernhard; Lang, Hermann

2017-01-01

Introduction The aim of the study was an evaluation of different approaches for guided bone regeneration (GBR) of peri-implant defects in an in vivo animal model. Materials and Methods In minipigs (n = 15), peri-implant defects around calcium phosphate- (CaP-; n = 46) coated implants were created and randomly filled with (1) blank, (2) collagen/hydroxylapatite/β-tricalcium phosphate scaffold (CHT), (3) CHT + growth factor cocktail (GFC), (4) jellyfish collagen matrix, (5) jellyfish collagen matrix + GFC, (6) collagen powder, and (7) collagen powder + periodontal ligament stem cells (PDLSC). Additional collagen membranes were used for coverage of the defects. After 120 days of healing, bone growth was evaluated histologically (bone to implant contact (BIC;%)), vertical bone apposition (VBA; mm), and new bone height (NBH; %). Results In all groups, new bone formation was seen. Though, when compared to the blank group, no significant differences were detected for all parameters. BIC and NBH in the group with collagen matrix as well as the group with the collagen matrix + GFC were significantly less when compared to the collagen powder group (all: p < 0.003). Conclusion GBR procedures, in combination with CaP-coated implants, will lead to an enhancement of peri-implant bone growth. There was no additional significant enhancement of osseous regeneration when using GFC or PDLSC. PMID:28951742

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

Growth of magnetotactic sulfate-reducing bacteria in oxygen concentration gradient medium.

PubMed

Lefèvre, Christopher T; Howse, Paul A; Schmidt, Marian L; Sabaty, Monique; Menguy, Nicolas; Luther, George W; Bazylinski, Dennis A

2016-12-01

Although dissimilatory sulfate-reducing bacteria (SRB) are generally described as strictly anaerobic organisms with regard to growth, several reports have shown that some SRB, particularly Desulfovibrio species, are quite resistant to O 2 . For example, SRB remain viable in many aerobic environments while some even reduce O 2 to H 2 O. However, reproducible aerobic growth of SRB has not been unequivocally documented. Desulfovibrio magneticus is a SRB that is also a magnetotactic bacterium (MTB). MTB biomineralize magnetosomes which are intracellular, membrane-bounded, magnetic iron mineral crystals. The ability of D. magneticus to grow aerobically in several different media under air where an O 2 concentration gradient formed, or under O 2 -free N 2 gas was tested. Under air, cells grew as a microaerophilic band of cells at the oxic-anoxic interface in media lacking sulfate. These results show that D. magneticus is capable of aerobic growth with O 2 as a terminal electron acceptor. This is the first report of consistent, reproducible aerobic growth of SRB. This finding is critical in determining important ecological roles SRB play in the environment. Interestingly, the crystal structure of the magnetite crystals of D. magneticus grown under microaerobic conditions showed significant differences compared with those produced anaerobically providing more evidence that environmental parameters influence magnetosome formation. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

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.

The Effect on Somatic Growth of Surgical and Catheter Treatment of Secundum Atrial Septal Defects.

PubMed

Chlebowski, Meghan M; Dai, Hongying; Kaine, Stephen F

2017-10-01

Historical studies suggest an association between atrial septal defect (ASD) and impaired growth with inconsistent improvement following closure. Limited data exist regarding the impact on growth in the era of transcatheter therapy. To evaluate the effect of closure on growth, we conducted a retrospective review of patients undergoing surgical or transcatheter closure during two time periods. Four hundred patients with isolated secundum ASD were divided into three cohorts: early surgical, contemporary surgical, and transcatheter. Data collected included demographics; height, weight, and body mass index (BMI) percentiles; catheterization hemodynamics; and co-morbidities. For all cohorts, there was no significant change in height or weight percentiles during two years after ASD closure. Age at repair was later for contemporary surgical and transcatheter cohorts (p < 0.0001). In the transcatheter cohort, mean Qp:Qs was 1.65 ± 0.54, but there was no correlation between greater Qp:Qs and decreased somatic growth. Subgroup analysis for patients with any initial growth percentile <5th percentile demonstrated a significant change in weight and BMI percentiles in the first two years after closure (p < 0.0004). The advent of transcatheter therapy shifted institutional practice to later age at repair for both surgical and transcatheter closure. There was no significant change in weight and height percentiles during two years after closure. Only patients with initial weight and BMI <5th percentile had improved growth after treatment. Concern for impaired growth should not generally be an indication for early ASD repair. However, early repair may be indicated in children with existing significant growth failure.

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

USDA-ARS?s Scientific Manuscript database

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...

The Effect of Growth Environment on the Morphological and Extended Defect Evolution in GaN Grown by Metalorganic Chemical Vapor Deposition

NASA Astrophysics Data System (ADS)

Fini, P.; Wu, X.; Tarsa, E.; Golan, Y.; Srikant, V.; Keller, S.; Denbaars, S.; Speck, J.

1998-08-01

The evolution of morphology and associated extended defects in GaN thin films grown on sapphire by metalorganic chemical vapor deposition (MOCVD) are shown to depend strongly on the growth environment. For the commonly used two-step growth process, a change in growth parameter such as reactor pressure influences the initial high temperature (HT) GaN growth mechanism. By means of transmission electron microscopy (TEM), atomic force microscopy (AFM), and high resolution X-ray diffraction (HRXRD) measurements, it is shown that the initial density of HT islands on the nucleation layer (NL) and subsequently the threading dislocation density in the HT GaN film may be directly controlled by tailoring the initial HT GaN growth conditions.

Effects of Dietary Fatty Acids on Juvenile Salmon Growth, Biochemistry, and Aerobic Performance: A Laboratory Rearing Experiment

NASA Astrophysics Data System (ADS)

Litz, M. N. C.; Miller, J. A.; Copeman, L.; Hurst, T. P.

2016-02-01

Juvenile salmon undergo important physiological and ecological transitions as they migrate from freshwater to the ocean, a phase characterized by rapid growth and high mortality. It is becoming increasing clear that variations in nutritional quality of marine prey may be as important as prey quantity in determining salmon survival during this critical period in their life history. Growth potential, and hence survival, may be related to the size when salmon first become piscivorous. We tested the hypothesis that prey nutrient composition and predator nutritional history affects growth, biochemistry, and performance in a population of subyearling Chinook salmon (Onchorynchus tshawytscha). Salmon were reared for 12 weeks on three energetically similar experimental diets. Diets were created with ratios of docosahexaenoic acid (DHA) to eicosapentaenoic acid (EPA) of 0.56, 0.94, and 1.47 by altering the amount of krill, anchovy, and two fatty acid supplements. Tagged salmon reared on the high DHA:EPA anchovy diet trended towards faster growth (0.33±0.05 mm d-1) compared to fish reared on the low DHA:EPA krill diet (0.27±0.03 mm d-1) or blended diet (0.29±0.02 mm d-1). Tissue turnover in salmon, measured in half-lives, was 5 to 28 days for essential fatty acids, and 9 to 184 days for bulk isotopes of nitrogen and carbon, indicating that predator tissue fatty acids reflect diet sooner than stable isotopes. After the rearing experiment, salmon were starved for 4 weeks and their critical swimming speeds measured to determine whether nutritional history had an affect on aerobic performance. Although there were no significant differences in swim performance among diet treatments, there was a significant relationship (r2=0.57, p=0.02) between swimming speed and an individual's size and storage lipids across diet treatments. Results from this study will support future ecological studies of migrating juvenile salmon and quantitative estimates of diet in other anadromous fish.

Amphibacillus cookii sp. nov., a facultatively aerobic, spore-forming, moderately halophilic, alkalithermotolerant bacterium.

PubMed

Pugin, Benoît; Blamey, Jenny M; Baxter, Bonnie K; Wiegel, Juergen

2012-09-01

Novel strains of facultatively aerobic, moderately alkaliphilic and facultatively halophilic bacteria were isolated from a sediment sample taken from the Southern Arm of Great Salt Lake, Utah. Cells of strain JW/BP-GSL-QD(T) (and related strains JW/BP-GSL-RA and JW/BP-GSL-WB) were rod-shaped, spore-forming, motile bacteria with variable Gram-staining. Strain JW/BP-GSL-QD(T) grew under aerobic conditions between 14.5 and 47 °C (optimum 39 °C), in the pH(37 °C) range 6.5-10.3 (optimum pH(37 °C) 8.0), and between 0.1 and 4.5 M Na(+) (optimum 0.9 M Na(+)). No growth was observed in the absence of supplemented Na(+). Strain JW/BP-GSL-QD(T) utilized L-arabinose, D-fructose, D-galactose, D-glucose, inulin, lactose, maltose, mannitol, D-mannose, pyruvate, D-ribose, D-sorbitol, starch, trehalose, xylitol and D-xylose under both aerobic and anaerobic conditions, and used ethanol and methanol only under aerobic conditions. Strains JW/BP-GSL-WB and JW/BP-GSL-RA had the same profiles except that methanol was not used aerobically. During growth on glucose, the major organic compounds formed under aerobic conditions were acetate and lactate, and under anaerobic conditions, the fermentation products were formate, acetate, lactate and ethanol. Oxidase and catalase activities were not detected and cytochrome was absent. No respiratory quinones were detected. The main cellular fatty acids were iso-C(15 : 0) (39.1 %) and anteiso-C(15 : 0) (36.3 %). Predominant polar lipids were diphosphatidylglycerol, phosphatidylglycerol and an unknown phospholipid. Additionally, a small amount of an unknown glycolipid was detected. The DNA G+C content of strain JW/BP-GSL-QD(T) was 35.4 mol% (determined by HPLC). For strain JW/BP-GSL-QD(T) the highest degree of 16S rRNA gene sequence similarity was found with Amphibacillus jilinensis (98.6 %), Amphibacillus sediminis (96.7 %) and Amphibacillus tropicus (95.6 %). The level of DNA-DNA relatedness between strain JW/BP-GSL-QD(T) and A. jilinensis Y1

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.

Effect of aerobic vs combined aerobic-strength training on 1-year, post-cardiac rehabilitation outcomes in women after a cardiac event.

PubMed

Arthur, Heather M; Gunn, Elizabeth; Thorpe, Kevin E; Ginis, Kathleen Martin; Mataseje, Lin; McCartney, Neil; McKelvie, Robert S

2007-11-01

To compare the effect and sustainability of 6 months combined aerobic/strength training vs aerobic training alone on quality of life in women after coronary artery by-pass graft surgery or myocardial infarction. Prospective, 2-group, randomized controlled trial. Ninety-two women who were 8-10 weeks post-coronary artery by-pass graft surgery or myocardial infarction, able to attend supervised exercise, and fluent in English. The aerobic training alone group had supervised exercise twice a week for 6 months. The aerobic/strength training group received aerobic training plus upper and lower body resistance exercises. The amount of active exercise time was matched between groups. The primary outcome, quality of life, was measured by the MOS SF-36; secondary outcomes were self-efficacy, strength and exercise capacity. After 6 months of supervised exercise training both groups showed statistically significant improvements in physical quality of life (p = 0.0002), peak VO2 (19% in aerobic/strength training vs 22% in aerobic training alone), strength (p < 0.0001) and self-efficacy for stair climbing (p = 0.0024), lifting (p < 0.0001) and walking (p = 0.0012). However, by 1-year follow-up there was a statistically significant difference in physical quality of life in favor of the aerobic/strength training group (p = 0.05). Women with coronary artery disease stand to benefit from both aerobic training alone and aerobic/strength training. However, continued improvement in physical quality of life may be achieved through combined strength and aerobic training.

Resistance training and aerobic training improve muscle strength and aerobic capacity in chronic inflammatory demyelinating polyneuropathy.

PubMed

Markvardsen, Lars H; Overgaard, Kristian; Heje, Karen; Sindrup, Søren H; Christiansen, Ingelise; Vissing, John; Andersen, Henning

2018-01-01

We investigated the effects of aerobic and resistance exercise in patients with chronic inflammatory demyelinating polyneuropathy (CIDP). Eighteen CIDP patients treated with subcutaneous immunoglobulin performed 12 weeks of aerobic exercise and 12 weeks of resistance exercise after a run-in period of 12 weeks without exercise. Three times weekly the participants performed aerobic exercise on an ergometer bike or resistance exercise with unilateral training of knee and elbow flexion/extension. Primary outcomes were maximal oxygen consumption velocity (VO 2 -max) and maximal combined isokinetic muscle strength (cIKS) of knee and elbow flexion/extension. VO 2 -max and muscle strength were unchanged during run-in (-4.9% ± 10.3%, P = 0.80 and -3.7% ± 10.1%, P = 0.17, respectively). Aerobic exercise increased VO 2 -max by 11.0% ± 14.7% (P = 0.02). Resistance exercise resulted in an increase of 13.8% ± 16.0% (P = 0.0004) in cIKS. Aerobic exercise training and resistance exercise training improve fitness and strength in CIDP patients. Muscle Nerve 57: 70-76, 2018. © 2017 Wiley Periodicals, Inc.

Influence of dendrite network defects on channel segregate growth

NASA Technical Reports Server (NTRS)

Simpson, M.; Yerebakan, M.; Flemings, M. C.

1985-01-01

The solidifying ingot interdendritic flow analysis in which channel segregates are assumed to be produced by interdendritic fluid flow dissolving channels in the primary dendrite network is presently refined by examining the flow through a dendrite network possessing a small defect. Attention is given to the section of the mushy zone in a solidifying casting. Since defects such as that presently treated are unavoidable in a real casting, a more reliable indication may be furnished of the occurrence of channel segregates.

High skin temperature and hypohydration impair aerobic performance.

PubMed

Sawka, Michael N; Cheuvront, Samuel N; Kenefick, Robert W

2012-03-01

This paper reviews the roles of hot skin (>35°C) and body water deficits (>2% body mass; hypohydration) in impairing submaximal aerobic performance. Hot skin is associated with high skin blood flow requirements and hypohydration is associated with reduced cardiac filling, both of which act to reduce aerobic reserve. In euhydrated subjects, hot skin alone (with a modest core temperature elevation) impairs submaximal aerobic performance. Conversely, aerobic performance is sustained with core temperatures >40°C if skin temperatures are cool-warm when euhydrated. No study has demonstrated that high core temperature (∼40°C) alone, without coexisting hot skin, will impair aerobic performance. In hypohydrated subjects, aerobic performance begins to be impaired when skin temperatures exceed 27°C, and even warmer skin exacerbates the aerobic performance impairment (-1.5% for each 1°C skin temperature). We conclude that hot skin (high skin blood flow requirements from narrow skin temperature to core temperature gradients), not high core temperature, is the 'primary' factor impairing aerobic exercise performance when euhydrated and that hypohydration exacerbates this effect.

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

USDA-ARS?s Scientific Manuscript database

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...

Aerobic sludge granulation for simultaneous anaerobic decolorization and aerobic aromatic amines mineralization for azo dye wastewater treatment.

PubMed

Yan, Lawrence K Q; Fung, Ka Y; Ng, Ka M

2018-06-01

In this study, the capability of using aerobic granules to undergo simultaneous anaerobic decolorization and aerobic aromatic amines degradation was demonstrated for azo dye wastewater treatment. An integrated acclimation-granulation process was devised, with Mordant Orange 1 as the model pollutant. Performance tests were carried out in a batch column reactor to evaluate the effect of various operating parameters. The optimal condition was to use 1.0-1.7 mm (1.51 ± 0.33 mm) granules, 5 g/L biomass, and 4000 mg/L organics as nutrient; and supplement the wastewater with 1  mg/L dissolved oxygen. This led to a dye mineralization of 61 ± 2%, an anaerobic dye removal of 88 ± 1%, and an aerobic aromatic amines removal of 70 ± 3% within 48 h. This study showed that simultaneous anaerobic/aerobic process by aerobic granules could be a possible alternative to the conventional activated sludge process.

Monitoring of growth and physiological activities of biofilm during succession on polystyrene from activated sludge under aerobic and anaerobic conditions.

PubMed

Naz, Iffat; Batool, Syeda Ain-ul; Ali, Naeem; Khatoon, Nazia; Atiq, Niama; Hameed, Abdul; Ahmed, Safia

2013-08-01

The present research work monitored the successive biofilm development and its catabolic role in the degradation of polystyrene (PS). PS material was artificially colonized with biofilm by incubating it with activated sludge under aerobic and anaerobic conditions. Biofilm formation was monitored by gravimetric weight analysis, spectrophotometric absorbance technique, heterotrophic plate count, and scanning electron microscopy under aerobic and anaerobic conditions. The wet weight (1.59 and 1.17 g) and dry weight (0.41 and 0.08 g) of a biofilm showed a significant constant increase under aerobic and anaerobic conditions, respectively, from first till 9 weeks of incubation. Plate count of the selected bacteria (Escherichia coli, Salmonella typhimurium, Shigella dysenteriae, Pseudomonas aeruginosa) considerably declined (90-99 %) in the biofilm after seventh and fifth weeks of incubation under aerobic and anaerobic conditions, respectively, indicating a positive shift from pathogenic to beneficial microbial community. While most probable number index of fecal coliforms and E. coli in the sludge showed more reduction (98 and 99 %) under aerobic as compare to anaerobic conditions (86 and 91 %) after 9 weeks of biofilm formation on PS cubes. Correspondingly, the decreasing levels of chemical oxygen demand and biochemical oxygen demand (up to 73 %) showed signs of sludge digestion. Scanning electron microscope coupled with energy dispersive X-ray spectroscope revealed nature of PS media containing high carbon content. However, biofilm development proved to be involved in the biochemical transformation of the PS medium as indicated by Fourier transform infrared spectroscopy.

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

Devitalization of bacterial and parasitic germs in sewage sludge during aerobic digestion under laboratory conditions.

PubMed

Juris, P; Plachý, P; Lauková, A

1995-05-01

The survival of 8 bacterial species (Pseudomonas sp., Salmonella sp., Enterobacteriae, Streptococcus sp., Escherichia coli) was detected in municipal sewage sludge up to 37 hours of mesophilic aerobic digestion under laboratory conditions. The model strain Enterococcus faecium CCM 4231 survived almost twice as long as the above-mentioned isolates. Similar findings, regarding the viability of the microorganisms studied, were also determined during thermophilic aerobic digestion of municipal sewage sludges. The final reduction in the total count of bacteria was not directly dependent on the temperature during aerobic digestion. It may be supposed that E. faecium CCM 4231 strain as a bacteriocin-producing strain with a broad antimicrobial spectrum, inoculated into the sludges, could inhibit the growth of microorganisms in the sludges by the way of its bacteriocin activity. Studying the effect of aerobic digestion on the viability of helminth eggs, the observed negative effect of higher temperatures was more expressive in comparison with bacterial strains. During thermophilic digestion process all helminth eggs (Ascaris suum, Toxocara canis) were devitalized. All eggs of T. canis were killed in experiments under mesophilic temperature. However, 32% of nonembryonated A. suum eggs remained viable.

[Moderately haloalkaliphilic aerobic methylobacteria].

PubMed

Trotsenko, Iu A; Doronina, N V; Li, Ts D; Reshetnikov, A S

2007-01-01

Aerobic methylobacteria utilizing oxidized and substituted methane derivatives as carbon and energy sources are widespread in nature and involved in the global carbon cycle, being a unique biofilter on the path of these C1 compounds from different ecosystems to the atmosphere. New data on the biological features of moderately halophilic, neutrophilic, and alkaliphilic methylobacteria isolated from biotopes with higher osmolarity (seas, saline and soda lakes, saline soils, and deteriorating marble) are reviewed. Particular attention is paid to the latest advances in the study of the mechanisms of osmoadaptation of aerobic moderately haloalkaliphilic methylobacteria: formation of osmolytes, in particular, molecular and genetic aspects of biosynthesis of the universal bioprotectant ectoine. The prospects for further studies of the physiological and biochemical principles of haloalkalophily and for the application of haloalkaliphilic aerobic methylobacteria in biosynthesis and biodegradation are discussed.

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…

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…

Clinical Evaluation of Insulin like Growth Factor-I and Vascular Endothelial Growth Factor with Alloplastic Bone Graft Material in the Management of Human Two Wall Intra-Osseous Defects

PubMed Central

Dixit, Jaya

2016-01-01

Introduction In recent years, emphasis on the use of growth factors for periodontal healing is gaining great momentum. Several growth factors showed promising results in periodontal regeneration. Aim This study was designed to compare the clinical outcomes of 0.8μg recombinant human Vascular Endothelial Growth Factor (rh-VEGF) and 10μg recombinant human Insulin Like Growth Factor-I (rh-IGF-I) with β-Tricalcium Phosphate (β-TCP) and Polylactide-Polyglycolide Acid (PLGA) membrane in two wall intra-osseous defects. Materials and Methods A total of 29 intra-osseous defects in 27 subjects were randomly divided into 3 test and 1 control group. Test group I (n=8) received rh-VEGF+ rh-IGF-I, Test group II (n=7) rh-VEGF, Test group III (n=7) rh-IGF-I and control group (n=7) with no growth factor, β-TCP and PLGA membrane was used in all the groups. Baseline soft tissue parameters including Probing Pocket Depth (PPD), Clinical Attachment Level (CAL), and Gingival Recession (GR) at selected sites were recorded at baseline and at 6 months. Intrasurgically, intra-osseous component was calculated as a) Cemento-Enamel Junction to Bone Crest (CEJ to BC), b) Bone Crest to Base of the Defect (BC to BD) at baseline and at re-entry. The mean changes at baseline and after 6 months within each group were compared using Wilcoxon Signed Rank Test. The mean changes for each parameter between groups were compared using Mann-Whitney U test. Results After 6 months, maximum mean PPD reduction occurred in test group I followed by test group II, III and control group. Similar trend was observed in CAL gain. Non-significant GR was present in test group I and control group whereas in test group II and III GR was absent. The use of rh-VEGF+ rhIGF-I exhibited 95.8% osseous fill as compared to 54.8% in test group II, 52.7% in test group III and 41.1 % in the control group. Conclusion Within the limitations of this study, it can be concluded that, rh-IGF-I+rh-VEGF treated sites resulted in greater

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haghighi Poodeh, Saeid, E-mail: saeid.haghighi@oulu.fi; Medical Research Center, Oulu University Hospital, Oulu; Alhonen, Leena

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 andmore » 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

Fatigue Crack Prognostics by Optical Quantification of Defect Frequency

NASA Astrophysics Data System (ADS)

Chan, K. S.; Buckner, B. D.; Earthman, J. C.

2018-01-01

Defect frequency, a fatigue crack prognostics indicator, is defined as the number of microcracks per second detected using a laser beam that is scanned across a surface at a constant predetermined frequency. In the present article, a mechanistic approach was taken to develop a methodology for deducing crack length and crack growth information from defect frequency data generated from laser scanning measurements made on fatigued surfaces. The method was developed by considering a defect frequency vs fatigue cycle curve that comprised three regions: (i) a crack initiation regime of rising defect frequency, (ii) a plateau region of a relatively constant defect frequency, and (iii) a region of rapid rising defect frequency due to crack growth. Relations between defect frequency and fatigue cycle were developed for each of these three regions and utilized to deduce crack depth information from laser scanning data of 7075-T6 notched specimens. The proposed method was validated using experimental data of crack density and crack length data from the literature for a structural steel. The proposed approach was successful in predicting the length or depth of small fatigue cracks in notched 7075-T6 specimens and in smooth fatigue specimens of a structural steel.

Defects in GaAs films grown by MOMBE

NASA Astrophysics Data System (ADS)

Werner, K.; Heinecke, H.; Weyers, M.; Lüth, H.; Balk, P.

1987-02-01

The nature and densities of the defects obtained in MOMBE GaAs films have been studied. In addition to particulate matter deposited on the surface, imperfections in the substrate will lead to defect generation. Furthermore, the rate of generation is strongly affected by the ratio of the pressures of the group III alkyl and the group V hydride in the molecular beams and by the growth temperature, also on defect-free substrates. Doping has no effect on the defect structure of the surface. By proper choice of experimental conditions defect densities below 100 cm -2 may be consistently obtained.

Filamentous bacteria existence in aerobic granular reactors.

PubMed

Figueroa, M; Val del Río, A; Campos, J L; Méndez, R; Mosquera-Corral, A

2015-05-01

Filamentous bacteria are associated to biomass settling problems in wastewater treatment plants. In systems based on aerobic granular biomass they have been proposed to contribute to the initial biomass aggregation process. However, their development on mature aerobic granular systems has not been sufficiently studied. In the present research work, filamentous bacteria were studied for the first time after long-term operation (up to 300 days) of aerobic granular systems. Chloroflexi and Sphaerotilus natans have been observed in a reactor fed with synthetic wastewater. These filamentous bacteria could only come from the inoculated sludge. Thiothrix and Chloroflexi bacteria were observed in aerobic granular biomass treating wastewater from a fish canning industry. Meganema perideroedes was detected in a reactor treating wastewater from a plant processing marine products. As a conclusion, the source of filamentous bacteria in these mature aerobic granular systems fed with industrial effluents was the incoming wastewater.

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.

Research on growth and defects of 5 in. YCOB single crystal

NASA Astrophysics Data System (ADS)

Tu, Xiaoniu; Wang, Sheng; Xiong, Kainan; Zheng, Yanqing; Shi, Erwei

2018-04-01

YCa4O(BO3)3 (YCOB) is an important nonlinear optical crystal, which is a key optical element in the SHG and OPCPA process to obtain high repetition rate, multi-petawatt laser pulse. In this work, we have grown 5 in. YCOB crystals by Czochralski method and investigated phase separation, defects, as well as their formation mechanism. Laser induced damage threshold (LiDT), rocking curve and transmission spectrum is characterized using the sample without defects. It is believed that, based on this work, large-sized YCOB crystal without defects will be obtained in the near future.

Aerobic exercise deconditioning and countermeasures during bed rest.

PubMed

Lee, Stuart M C; Moore, Alan D; Everett, Meghan E; Stenger, Michael B; Platts, Steven H

2010-01-01

Bed rest is a well-accepted model for spaceflight in which the physiologic adaptations, particularly in the cardiovascular system, are studied and potential countermeasures can be tested. Bed rest without countermeasures results in reduced aerobic capacity and altered submaximal exercise responses. Aerobic endurance and factors which may impact prolonged exercise, however, have not been well studied. The initial loss of aerobic capacity is rapid, occurring in parallel with the loss of plasma volume. Thereafter, the reduction in maximal aerobic capacity proceeds more slowly and is influenced by central and peripheral adaptation. Exercise capacity can be maintained during bed rest and may be improved during recovery with appropriate countermeasures. Plasma volume restoration, resistive exercise, orthostatic stress, aerobic exercise, and aerobic exercise plus orthostatic stress all have been tested with varying levels of success. However, the optimal combination of elements-exercise modality, intensity, duration, muscle groups exercised and frequency of aerobic exercise, orthostatic stress, and supplementary resistive or anaerobic exercise training-has not been systematically evaluated. Currently, frequent (at least 3 days per week) bouts of intense exercise (interval-style and near maximal) with orthostatic stress appears to be the most efficacious method to protect aerobic capacity during bed rest. Further refinement of protocols and countermeasure hardware may be necessary to insure the success of countermeasures in the unique environment of space.

Doping-assisted defect control in compound semiconductors

DOEpatents

Specht, Petra; Weber, Eicke R.; Weatherford, Todd Russell

2006-07-11

The present invention relates to the production of thin film epilayers of III–V and other compounds with acceptor doping wherein the acceptor thermally stabilizes the epilayer, stabilize the naturally incorporated native defect population and therewith maintain the epilayer's beneficial properties upon annealing among other advantageous effects. In particular, balanced doping in which the acceptor concentration is similar to (but does not exceed) the antisite defects in the as-grown material is shown to be particularly advantageous in providing thermal stability, high resistivity and ultrashort trapping times. In particular, MBE growth of LT-GaAs epilayers with balanced Be doping is described in detail. The growth conditions greatly enhance the materials reproducibility (that is, the yield in processed devices). Such growth techniques can be transferred to other III–V materials if the growth conditions are accurately reproduced. Materials produced herein also demonstrate advantages in reproducibility, reliability and radiation hardening.

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.

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).…

Membrane thickening aerobic digestion processes.

PubMed

Woo, Bryen

2014-01-01

Sludge management accounts for approximately 60% of the total wastewater treatment plant expenditure and laws for sludge disposal are becoming increasingly stringent, therefore much consideration is required when designing a solids handling process. A membrane thickening aerobic digestion process integrates a controlled aerobic digestion process with pre-thickening waste activated sludge using membrane technology. This process typically features an anoxic tank, an aerated membrane thickener operating in loop with a first-stage digester followed by second-stage digestion. Membrane thickening aerobic digestion processes can handle sludge from any liquid treatment process and is best for facilities obligated to meet low total phosphorus and nitrogen discharge limits. Membrane thickening aerobic digestion processes offer many advantages including: producing a reusable quality permeate with minimal levels of total phosphorus and nitrogen that can be recycled to the head works of a plant, protecting the performance of a biological nutrient removal liquid treatment process without requiring chemical addition, providing reliable thickening up to 4% solids concentration without the use of polymers or attention to decanting, increasing sludge storage capacities in existing tanks, minimizing the footprint of new tanks, reducing disposal costs, and providing Class B stabilization.

Nanoscale interfacial defect shedding in a growing nematic droplet.

PubMed

Gurevich, Sebastian; Provatas, Nikolas; Rey, Alejandro

2017-08-01

Interfacial defect shedding is the most recent known mechanism for defect formation in a thermally driven isotropic-to-nematic phase transition. It manifests in nematic-isotropic interfaces going through an anchoring switch. Numerical computations in planar geometry established that a growing nematic droplet can undergo interfacial defect shedding, nucleating interfacial defect structures that shed into the bulk as +1/2 point defects. By extending the study of interfacial defect shedding in a growing nematic droplet to larger length and time scales, and to three dimensions, we unveil an oscillatory growth mode involving shape and anchoring transitions that results in a controllable regular distributions of point defects in planar geometry, and complex structures of disclination lines in three dimensions.

Coordinated metabolic transitions during Drosophila embryogenesis and the onset of aerobic glycolysis.

PubMed

Tennessen, Jason M; Bertagnolli, Nicolas M; Evans, Janelle; Sieber, Matt H; Cox, James; Thummel, Carl S

2014-03-12

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. Copyright © 2014 Tennessen et al.

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, and…

Mapping crystal defects with a digital scanning ultramicroscope

NASA Astrophysics Data System (ADS)

Springer, John M., Jr.; Silberman, Enrique; Kroes, Roger L.; Reiss, Don

1991-12-01

A computer controlled scanning ultramicroscope has been built to assist in the characterization of transparent crystals. The device measures the scattering of a focused He-Ne laser beam by crystalline defects. As an XYZ translation table moves the crystal under the ultramicroscope, the scattered light is measured by a photodetector whose output is digitized and recorded. From this data, contour maps or 3-D perspective plots of the scattering regions of the crystal can be generated to assist in finding patterns of defects which might be correlated with perturbations in the growth process. The verified resolution of the present instrument is about 1 micrometers , which is limited by the minimum step of the stepper-motor driven translation stages, optical diffraction effects, and the sensitivity of the detector at the laser light frequency. The instrument was used to build a database of defects patterns in commercial laboratory grown triglycine sulphate (TGS) crystals, and to map defects in a TGS crystal grown from aqueous solution during the flight of Spacelab 3. This crystal shows indications of a reduction both in the generation of defects at the seed-new growth interface and in their propagation into the new crystal.

Mapping crystal defects with a digital scanning ultramicroscope

NASA Astrophysics Data System (ADS)

Springer, J. M.; Silberman, E.; Kroes, Roger; Reiss, D.

A computer controlled scanning ultramicroscope has been built to assist in the characterization of transparent crystals. The device measures the scattering of a focused He-Ne laser beam by crystalline defects. As an XYZ translation table moves the crystal under the ultramicroscope, the scattered light is measured by a photodetector whose output is digitized and recorded. From this data, contour maps or three dimensional perspective plots of the scattering regions of the crystal can be generated to assist in finding patterns of defects which might be correlated with perturbations in the growth process. The verified resolution of the present instrument is about 1 micrometer, which is limited by the minimum step of the stepper-motor driven translation stages, optical diffraction effects and the sensitivity of the detector at the laser light frequency. The instrument was used to build a database of defects patterns in commercial laboratory grown triglycine sulphate (TGS) crystals, and to map defects in a TGS crystal grown from aqueous solution during the flight of Spacelab 3. This crystal shows indications of a reduction both in the generation of defects at the seed-new growth interface and in their propagation into the new crystal.

Mapping crystal defects with a digital scanning ultramicroscope

NASA Technical Reports Server (NTRS)

Springer, J. M.; Silberman, E.; Kroes, Roger; Reiss, D.

1991-01-01

A computer controlled scanning ultramicroscope has been built to assist in the characterization of transparent crystals. The device measures the scattering of a focused He-Ne laser beam by crystalline defects. As an XYZ translation table moves the crystal under the ultramicroscope, the scattered light is measured by a photodetector whose output is digitized and recorded. From this data, contour maps or three dimensional perspective plots of the scattering regions of the crystal can be generated to assist in finding patterns of defects which might be correlated with perturbations in the growth process. The verified resolution of the present instrument is about 1 micrometer, which is limited by the minimum step of the stepper-motor driven translation stages, optical diffraction effects and the sensitivity of the detector at the laser light frequency. The instrument was used to build a database of defects patterns in commercial laboratory grown triglycine sulphate (TGS) crystals, and to map defects in a TGS crystal grown from aqueous solution during the flight of Spacelab 3. This crystal shows indications of a reduction both in the generation of defects at the seed-new growth interface and in their propagation into the new crystal.

A Redox-Responsive Transcription Factor Is Critical for Pathogenesis and Aerobic Growth of Listeria monocytogenes.

PubMed

Whiteley, Aaron T; Ruhland, Brittany R; Edrozo, Mauna B; Reniere, Michelle L

2017-05-01

Bacterial pathogens have evolved sophisticated mechanisms to sense and adapt to redox stress in nature and within the host. However, deciphering the redox environment encountered by intracellular pathogens in the mammalian cytosol is challenging, and that environment remains poorly understood. In this study, we assessed the contributions of the two redox-responsive, Spx-family transcriptional regulators to the virulence of Listeria monocytogenes , a Gram-positive facultative intracellular pathogen. Spx-family proteins are highly conserved in Firmicutes , and the L. monocytogenes genome contains two paralogues, spxA1 and spxA2 Here, we demonstrate that spxA1 , but not spxA2 , is required for the oxidative stress response and pathogenesis. SpxA1 function appeared to be conserved with the Bacillus subtilis homologue, and resistance to oxidative stress required the canonical CXXC redox-sensing motif. Remarkably, spxA1 was essential for aerobic growth, demonstrating that L. monocytogenes SpxA1 likely regulates a distinct set of genes. Although the Δ spxA1 mutant did not grow in the presence of oxygen in the laboratory, it was able to replicate in macrophages and colonize the spleens, but not the livers, of infected mice. These data suggest that the redox state of bacteria during infection differs significantly from that of bacteria growing in vitro Further, the host cell cytosol may resemble an anaerobic environment, with tissue-specific variations in redox stress and oxygen concentration. Copyright © 2017 Whiteley et al.

Novel role of NOX in supporting aerobic glycolysis in cancer cells with mitochondrial dysfunction and as a potential target for cancer therapy.

PubMed

Lu, Weiqin; Hu, Yumin; Chen, Gang; Chen, Zhao; Zhang, Hui; Wang, Feng; Feng, Li; Pelicano, Helene; Wang, Hua; Keating, Michael J; Liu, Jinsong; McKeehan, Wallace; Wang, Huamin; Luo, Yongde; Huang, Peng

2012-01-01

Elevated aerobic glycolysis in cancer cells (the Warburg effect) may be attributed to respiration injury or mitochondrial dysfunction, but the underlying mechanisms and therapeutic significance remain elusive. Here we report that induction of mitochondrial respiratory defect by tetracycline-controlled expression of a dominant negative form of DNA polymerase γ causes a metabolic shift from oxidative phosphorylation to glycolysis and increases ROS generation. We show that upregulation of NOX is critical to support the elevated glycolysis by providing additional NAD+. The upregulation of NOX is also consistently observed in cancer cells with compromised mitochondria due to the activation of oncogenic Ras or loss of p53, and in primary pancreatic cancer tissues. Suppression of NOX by chemical inhibition or genetic knockdown of gene expression selectively impacts cancer cells with mitochondrial dysfunction, leading to a decrease in cellular glycolysis, a loss of cell viability, and inhibition of cancer growth in vivo. Our study reveals a previously unrecognized function of NOX in cancer metabolism and suggests that NOX is a potential novel target for cancer treatment.

Patients' perspectives on aerobic exercise early after stroke.

PubMed

Prout, Erik C; Mansfield, Avril; McIlroy, William E; Brooks, Dina

2017-04-01

To describe patient perspectives of aerobic exercise during inpatient stroke rehabilitation, including their self-efficacy and beliefs towards exercise, as well as their perceptions of barriers. A survey was conducted at three Canadian rehabilitation centres to evaluate individuals' (N = 33) self-efficacy and outcome expectations for exercise. In addition, patient perceptions of other people recovering from stroke, social support, and aerobic exercise as part of rehabilitation were assessed. Thirty-two people completed the survey. Of these, 97% were willing to participate in aerobic exercise 5.9 ± 8.8 days after admission to inpatient rehabilitation. While outcome expectations for exercise were high, participants reported lower self-efficacy for exercise. Patients reported barriers related to the ability to perform exercise (other health problems (i.e., arthritis), not being able to follow instructions and physical impairments) more often than safety concerns (fear of falling). The lack of support from a spouse and family were commonly identified, as was a lack of information on how to perform aerobic exercise. Patients with stroke are willing to participate in aerobic exercise within a week after admission to inpatient rehabilitation. However, they perceive a lack of ability to perform aerobic exercise, social support from family and information as barriers. Implications for rehabilitation Aerobic exercise is recognized as part of comprehensive stroke rehabilitation. There is a need to better understand patient perspectives to develop and implement more effective interventions early after stroke. Patients lack confidence in their ability to overcome barriers early after stroke. Patients are concerned with their ability to perform exercise, fall risk, lack of support from a spouse and family, and limited information on aerobic exercise. There is a need to reinforce education with practical experience in structured aerobic exercise programs that show

Mitigation of substrate defects in reticles using multilayer buffer layers

DOEpatents

Mirkarimi, Paul B.; Bajt, Sasa; Stearns, Daniel G.

2001-01-01

A multilayer film is used as a buffer layer to minimize the size of defects on a reticle substrate prior to deposition of a reflective coating on the substrate. The multilayer buffer layer deposited intermediate the reticle substrate and the reflective coating produces a smoothing of small particles and other defects on the reticle substrate. The reduction in defect size is controlled by surface relaxation during the buffer layer growth process and by the degree of intermixing and volume contraction of the materials at the multilayer interfaces. The buffer layers are deposited at near-normal incidence via a low particulate ion beam sputtering process. The growth surface of the buffer layer may also be heated by a secondary ion source to increase the degree of intermixing and improve the mitigation of defects.

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…

Aerobic Fitness Linked to Cortical Brain Development in Adolescent Males: Preliminary Findings Suggest a Possible Role of BDNF Genotype.

PubMed

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.

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

Effect of complex aerobic physical exercise on PSD-95 in the hippocampus and on cognitive function in juvenile mice

NASA Astrophysics Data System (ADS)

Satriani, W. H.; Redjeki, S.; Kartinah, N. T.

2017-08-01

Increased neuroplasticity induced by complex aerobic physical exercise is associated with improved cognitive function in adult mice. Increased cognitive function is assumed to be based on increased synapse formation. One of the regions of the brain that is important in cognitive function is the hippocampus, which plays a role in memory formation. Post synaptic density-95 (PSD-95) is an adhesion protein of the post-synaptic density scaffolding that is essential to synaptic stabilization. As we age, the PSD-95 molecule matures the synapses needed for the formation of the basic circuitry of the nervous system in the brain. However, during the growth period, synapse elimination is higher than its formation. This study aims to determine whether complex aerobic exercise can improve cognitive function and PSD-95 levels in the hippocampus of juvenile mice during their growth stage. The mice performed complex aerobic exercise starting at five weeks of age and continuing for seven weeks with a gradual increase of 8 m/min. At eight weeks it was increased to 10 m/min. The exercise was done for five days of each week. The subjects of the study were tested for cognition one week before being sacrificed (at 12 weeks). The PSD-95 in the hippocampus was measured with ELISA. The results showed that there was a significant difference in cognitive function, where p < 0.05, between the group that was given complex aerobic exercise and a control group that did not. However, the PSD-95 levels did not differ significantly between the two groups. The results of this study indicate that early complex aerobic exercise can improve cognitive ability in adulthood but does not increase the levels of PSD-95 in adults.

Aerobic and anaerobic glucose metabolism of Phytomonas sp. isolated from Euphorbia characias.

PubMed

Chaumont, F; Schanck, A N; Blum, J J; Opperdoes, F R

1994-10-01

Metabolic studies on Phytomonas sp. isolated from the lactiferous tubes of the latex-bearing spurge Euphorbia characias indicate that glucose is the preferred energy and carbon substrate during logarithmic growth. In stationary phase cells glucose consumption was dramatically reduced. Glucose consumption and end-product formation were measured on logarithmically growing cells, both under aerobic (air and 95% O2/5% CO2) and anaerobic (95% N2/5% CO2 and 100% N2) conditions. The rate of glucose consumption slightly increased under anaerobic conditions indicating that Phytomonas lacks a 'reverse Pasteur' effect contrary to the situation encountered in Leishmania major. Major end-products of glucose catabolism under aerobic conditions, detected by enzymatic and NMR measurements, were acetate, ethanol and carbon dioxide and under anaerobic conditions ethanol, glycerol and carbon dioxide. Smaller amounts of pyruvate, succinate, L-malate, L-lactate, phosphoenolpyruvate, alanine and aspartate were also detected.

Influence of aerobic and anoxic microenvironments on polyhydroxyalkanoates (PHA) production from food waste and acidogenic effluents using aerobic consortia.

PubMed

Reddy, M Venkateswar; Mohan, S Venkata

2012-01-01

The functional role of aerobic and anoxic microenvironments on polyhydroxyalkanoates (PHA) production using food waste (UFW) and effluents from acidogenic biohydrogen production process (FFW) were studied employing aerobic mixed culture as biocatalyst. Anoxic microenvironment documented higher PHA production, while aerobic microenvironment showed higher substrate degradation. FFW showed higher PHA accumulation (39.6%) than UFW (35.6%) due to ready availability of precursors (fatty acids). Higher fraction of poly-3-hydroxy butyrate (PHB) was observed compared to poly-3-hydroxy valerate (PHV) in the accumulated PHA in the form of co-polymer [P3(HB-co-HV)]. Dehydrogenase, phosphatase and protease enzymatic activities were monitored during process operation. Integration with fermentative biohydrogen production yielded additional substrate degradation under both aerobic (78%) and anoxic (72%) microenvironments apart from PHA production. Microbial community analysis documented the presence of aerobic and facultative organisms capable of producing PHA. Integration strategy showed feasibility of producing hydrogen along with PHA by consuming fatty acids generated during acidogenic process in association with increased treatment efficiency. Copyright © 2011 Elsevier Ltd. All rights reserved.

Toxic and inhibitory effects of trichloroethylene aerobic co-metabolism on phenol-grown aerobic granules.

PubMed

Zhang, Yi; Tay, JooHwa

2015-04-09

Aerobic granule, a form of microbial aggregate, exhibits good potential in degrading toxic and recalcitrant substances. In this study, the inhibitory and toxic effects of trichloroethylene (TCE), a model compound for aerobic co-metabolism, on phenol-grown aerobic granules were systematically studied, using respiratory activities after exposure to TCE as indicators. High TCE concentration did not exert positive or negative effects on the subsequent endogenous respiration rate or phenol dependent specific oxygen utilization rate (SOUR), indicating the absence of solvent stress and induction effect on phenol-hydroxylase. Phenol-grown aerobic granules exhibited a unique response to TCE transformation product toxicity, that small amount of TCE transformation enhanced the subsequent phenol SOUR. Granules that had transformed between 1.3 and 3.7 mg TCE gSS(-1) showed at most 53% increase in the subsequent phenol SOUR, and only when the transformation exceeded 6.6 mg TCE gSS(-1) did the SOUR dropped below that of the control. This enhancing effect was found to sustain throughout several phenol dosages, and TCE transformation below the toxicity threshold also lessened the granules' sensitivity to higher phenol concentration. The unique toxic effect was possibly caused by the granule's compact structure as a protection barrier against the diffusive transformation product(s) of TCE co-metabolism. Copyright © 2015 Elsevier B.V. All rights reserved.

Reliability-based management of buried pipelines considering external corrosion defects

NASA Astrophysics Data System (ADS)

Miran, Seyedeh Azadeh

Corrosion is one of the main deteriorating mechanisms that degrade the energy pipeline integrity, due to transferring corrosive fluid or gas and interacting with corrosive environment. Corrosion defects are usually detected by periodical inspections using in-line inspection (ILI) methods. In order to ensure pipeline safety, this study develops a cost-effective maintenance strategy that consists of three aspects: corrosion growth model development using ILI data, time-dependent performance evaluation, and optimal inspection interval determination. In particular, the proposed study is applied to a cathodic protected buried steel pipeline located in Mexico. First, time-dependent power-law formulation is adopted to probabilistically characterize growth of the maximum depth and length of the external corrosion defects. Dependency between defect depth and length are considered in the model development and generation of the corrosion defects over time is characterized by the homogenous Poisson process. The growth models unknown parameters are evaluated based on the ILI data through the Bayesian updating method with Markov Chain Monte Carlo (MCMC) simulation technique. The proposed corrosion growth models can be used when either matched or non-matched defects are available, and have ability to consider newly generated defects since last inspection. Results of this part of study show that both depth and length growth models can predict damage quantities reasonably well and a strong correlation between defect depth and length is found. Next, time-dependent system failure probabilities are evaluated using developed corrosion growth models considering prevailing uncertainties where three failure modes, namely small leak, large leak and rupture are considered. Performance of the pipeline is evaluated through failure probability per km (or called a sub-system) where each subsystem is considered as a series system of detected and newly generated defects within that sub

The use of fatty acid methyl esters as biomarkers to determine aerobic, facultatively aerobic and anaerobic communities in wastewater treatment systems.

PubMed

Quezada, Maribel; Buitrón, Germán; Moreno-Andrade, Iván; Moreno, Gloria; López-Marín, Luz M

2007-01-01

The use of fatty acid methyl esters (FAME) as biomarkers to identify groups of microorganisms was studied. A database was constructed using previously published results that identify FAME biomarkers for aerobic, anaerobic and facultatively aerobic bacteria. FAME profiles obtained from pure cultures were utilized to confirm the predicted presence of biomarkers. Principal component analysis demonstrated that the FAME profiles can be used to determine the incidence of these bacterial groups. The presence of aerobic, anaerobic and facultatively aerobic bacteria in the communities, in four bioreactors being used to treat different wastewaters, was investigated by applying FAME biomarkers.

Defect structure of high temperature hydride vapor phase epitaxy-grown epitaxial (0 0 0 1) AlN/sapphire using growth mode modification process

NASA Astrophysics Data System (ADS)

Su, Xujun; Zhang, Jicai; Huang, Jun; Zhang, Jinping; Wang, Jianfeng; Xu, Ke

2017-06-01

Defect structures were investigated by transmission electron microscopy for AlN/sapphire (0 0 0 1) epilayers grown by high temperature hydride vapor phase epitaxy using a growth mode modification process. The defect structures, including threading dislocations, inversion domains, and voids, were analyzed by diffraction contrast, high-resolution imaging, and convergent beam diffraction. AlN film growth was initiated at 1450 °C with high V/III ratio for 8 min. This was followed by low V/III ratio growth for 12 min. The near-interfacial region shows a high density of threading dislocations and inversion domains. Most of these dislocations have Burgers vector b = 1/3〈1 1 2 0〉 and were reduced with the formation of dislocation loops. In the middle range 400 nm < h < 2 μm, dislocations gradually aggregated and reduced to ∼109 cm-2. The inversion domains have a shuttle-like shape with staggered boundaries that deviate by ∼ ±5° from the c axis. Above 2 μm thickness, the film consists of isolated threading dislocations with a total density of 8 × 108 cm-2. Most of threading dislocations are either pure edge or mixed dislocations. The threading dislocation reduction in these films is associated with dislocation loops formation and dislocation aggregation-interaction during island growth with high V/III ratio.

Acclimation of aerobic-activated sludge degrading benzene derivatives and co-metabolic degradation activities of trichloroethylene by benzene derivative-grown aerobic sludge.

PubMed

Wang, Shizong; Yang, Qi; Bai, Zhiyong; Wang, Shidong; Wang, Yeyao; Nowak, Karolina M

2015-01-01

The acclimation of aerobic-activated sludge for degradation of benzene derivatives was investigated in batch experiments. Phenol, benzoic acid, toluene, aniline and chlorobenzene were concurrently added to five different bioreactors which contained the aerobic-activated sludge. After the acclimation process ended, the acclimated phenol-, benzoic acid-, toluene-, aniline- and chlorobenzene-grown aerobic-activated sludge were used to explore the co-metabolic degradation activities of trichloroethylene (TCE). Monod equation was employed to simulate the kinetics of co-metabolic degradation of TCE by benzene derivative-grown sludge. At the end of experiments, the mixed microbial communities grown under different conditions were identified. The results showed that the acclimation periods of microorganisms for different benzene derivatives varied. The maximum degradation rates of TCE for phenol-, benzoic acid-, toluene-, aniline- and chlorobenzene-grown aerobic sludge were 0.020, 0.017, 0.016, 0.0089 and 0.0047 mg g SS(-1) h(-1), respectively. The kinetic of TCE degradation in the absence of benzene derivative followed Monod equation well. Also, eight phyla were observed in the acclimated benzene derivative-grown aerobic sludge. Each of benzene derivative-grown aerobic sludge had different microbial community composition. This study can hopefully add new knowledge to the area of TCE co-metabolic by mixed microbial communities, and further the understanding on the function and applicability of aerobic-activated sludge.

Aerobic Stability and Effects of Yeasts during Deterioration of Non-fermented and Fermented Total Mixed Ration with Different Moisture Levels.

PubMed

Hao, W; Wang, H L; Ning, T T; Yang, F Y; Xu, C C

2015-06-01

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 10(7) to 10(10) 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 10(9) 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.

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

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. Copyright © 2016 Elsevier Inc. All rights reserved.

High Skin Temperature and Hypohydration Impair Aerobic Performance

DTIC Science & Technology

2012-01-01

hypohydration) in impairing submaximal aerobic performance. Hot skin is associated with high skin blood flow requirements and hypohydration is...the aerobic performance impairment (-1.5% for each l°C skin temperature). We conclude that hot skin ( high skin blood flow requirements from narrow...associated with high skin blood flow requirements and hypohydration is associated with reduced cardiac filling, both of which act to reduce aerobic

Epitaxial growth mechanisms of graphene and effects of substrates

NASA Astrophysics Data System (ADS)

Özçelik, V. Ongun; Cahangirov, S.; Ciraci, S.

2012-06-01

The growth process of single layer graphene with and without substrate is investigated using ab initio, finite temperature molecular dynamic calculations within density functional theory. An understanding of the epitaxial graphene growth mechanisms in the atomic level is provided by exploring the transient stages which occur at the growing edges of graphene. These stages are formation and collapse of large carbon rings together with the formation and healing of Stone-Wales like pentagon-heptagon defects. The activation barriers for the healing of these growth induced defects on various substrates are calculated using the climbing image nudge elastic band method and compared with that of the Stone-Wales defect. It is found that the healing of pentagon-heptagon defects occurring near the edge in the course of growth is much easier than that of Stone-Wales defect. The role of the substrate in the epitaxial growth and in the healing of defects are also investigated in detail, along with the effects of using carbon dimers as the building blocks of graphene growth.

Cardioprotective effects of early and late aerobic exercise training in experimental pulmonary arterial hypertension.

PubMed

Moreira-Gonçalves, Daniel; Ferreira, Rita; Fonseca, Hélder; Padrão, Ana Isabel; Moreno, Nuno; Silva, Ana Filipa; Vasques-Nóvoa, Francisco; Gonçalves, Nádia; Vieira, Sara; Santos, Mário; Amado, Francisco; Duarte, José Alberto; Leite-Moreira, Adelino F; Henriques-Coelho, Tiago

2015-11-01

Clinical studies suggest that aerobic exercise can exert beneficial effects in pulmonary arterial hypertension (PAH), but the underlying mechanisms are largely unknown. We compared the impact of early or late aerobic exercise training on right ventricular function, remodeling and survival in experimental PAH. Male Wistar rats were submitted to normal cage activity (SED), exercise training in early (EarlyEX) and in late stage (LateEX) of PAH induced by monocrotaline (MCT, 60 mg/kg). Both exercise interventions resulted in improved cardiac function despite persistent right pressure-overload, increased exercise tolerance and survival, with greater benefits in EarlyEX+MCT. This was accompanied by improvements in the markers of cardiac remodeling (SERCA2a), neurohumoral activation (lower endothelin-1, brain natriuretic peptide and preserved vascular endothelial growth factor mRNA), metabolism and mitochondrial oxidative stress in both exercise interventions. EarlyEX+MCT provided additional improvements in fibrosis, tumor necrosis factor-alpha/interleukin-10 and brain natriuretic peptide mRNA, and beta/alpha myosin heavy chain protein expression. The present study demonstrates important cardioprotective effects of aerobic exercise in experimental PAH, with greater benefits obtained when exercise training is initiated at an early stage of the disease.

Is Maximum Food Intake in Endotherms Constrained by Net or Factorial Aerobic Scope? Lessons from the Leaf-Eared Mouse.

PubMed

Maldonado, Karin; Sabat, Pablo; Piriz, Gabriela; Bogdanovich, José M; Nespolo, Roberto F; Bozinovic, Francisco

2016-01-01

Food availability varies substantially throughout animals' lifespans, thus the ability to profit from high food levels may directly influence animal fitness. Studies exploring the link between basal metabolic rate (BMR), growth, reproduction, and other fitness traits have shown varying relationships in terms of both magnitude and direction. The diversity of results has led to the hypothesis that these relationships are modulated by environmental conditions (e.g., food availability), suggesting that the fitness consequences of a given BMR may be context-dependent. In turn, there is indirect evidence that individuals with an increased capacity for aerobic work also have a high capacity for acquiring energy from food. Surprisingly, very few studies have explored the correlation between maximum rates of energy acquisition and BMR in endotherms, and to the best of our knowledge, none have attempted to elucidate relationships between the former and aerobic capacity [e.g., maximum metabolic rate (MMR), aerobic scope (Factorial aerobic scope, FAS; Net aerobic scope, NAS)]. In this study, we measured BMR, MMR, maximum food intake (recorded under low ambient temperature and ad libitum food conditions; MFI), and estimated aerobic scope in the leaf-eared mouse ( Phyllotis darwini ). We, then, examined correlations among these variables to determine whether metabolic rates and aerobic scope are functionally correlated, and whether an increased aerobic capacity is related to a higher MFI. We found that aerobic capacity measured as NAS is positively correlated with MFI in endotherms, but with neither FAS nor BMR. Therefore, it appears plausible that the capacity for assimilating energy under conditions of abundant resources is determined adaptively by NAS, as animals with higher NAS would be promoted by selection. In theory, FAS is an invariant measurement of the extreme capacity for energy turnover in relation to resting expenditure, whereas NAS represents the maximum capacity

Metabolic reprogramming during neuronal differentiation from aerobic glycolysis to neuronal oxidative phosphorylation.

PubMed

Zheng, Xinde; Boyer, Leah; Jin, Mingji; Mertens, Jerome; Kim, Yongsung; Ma, Li; Ma, Li; Hamm, Michael; Gage, Fred H; Hunter, Tony

2016-06-10

How metabolism is reprogrammed during neuronal differentiation is unknown. We found that the loss of hexokinase (HK2) and lactate dehydrogenase (LDHA) expression, together with a switch in pyruvate kinase gene splicing from PKM2 to PKM1, marks the transition from aerobic glycolysis in neural progenitor cells (NPC) to neuronal oxidative phosphorylation. The protein levels of c-MYC and N-MYC, transcriptional activators of the HK2 and LDHA genes, decrease dramatically. Constitutive expression of HK2 and LDHA during differentiation leads to neuronal cell death, indicating that the shut-off aerobic glycolysis is essential for neuronal survival. The metabolic regulators PGC-1α and ERRγ increase significantly upon neuronal differentiation to sustain the transcription of metabolic and mitochondrial genes, whose levels are unchanged compared to NPCs, revealing distinct transcriptional regulation of metabolic genes in the proliferation and post-mitotic differentiation states. Mitochondrial mass increases proportionally with neuronal mass growth, indicating an unknown mechanism linking mitochondrial biogenesis to cell size.

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

NASA Astrophysics Data System (ADS)

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

2013-08-01

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.

Isolation and characterization of aerobic anoxygenic phototrophs from exposed soils from the Sør Rondane Mountains, East Antarctica.

PubMed

Tahon, Guillaume; Willems, Anne

2017-09-01

This study investigated the culturable aerobic phototrophic bacteria present in soil samples collected in the proximity of the Belgian Princess Elisabeth Station in the Sør Rondane Mountains, East Antarctica. Until recently, only oxygenic phototrophic bacteria (Cyanobacteria) were well known from Antarctic soils. However, more recent non-cultivation-based studies have demonstrated the presence of anoxygenic phototrophs and, particularly, aerobic anoxygenic phototrophic bacteria in these areas. Approximately 1000 isolates obtained after prolonged incubation under different growth conditions were studied and characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Representative strains were identified by sequence analysis of 16S rRNA genes. More than half of the isolates grouped among known aerobic anoxygenic phototrophic taxa, particularly with Sphingomonadaceae, Methylobacterium and Brevundimonas. In addition, a total of 330 isolates were tested for the presence of key phototrophy genes. While rhodopsin genes were not detected, multiple isolates possessed key genes of the bacteriochlorophyll synthesis pathway. The majority of these potential aerobic anoxygenic phototrophic strains grouped with Alphaproteobacteria (Sphingomonas, Methylobacterium, Brevundimonas and Polymorphobacter). Copyright © 2017 The Authors. Published by Elsevier GmbH.. All rights reserved.

Identification of short stature caused by SHOX defects and therapeutic effect of recombinant human growth hormone.

PubMed

Binder, G; Schwarze, C P; Ranke, M B

2000-01-01

Point mutations or complete deletions of SHOX, the short-stature homeobox-containing gene on the pseudoautosomal region of the sex chromosomes (Xp22 and Yp11.3), were recently reported in one family with idiopathic short stature and in several families with Leri-Weill syndrome (dyschondrosteosis). The missing SHOX is also thought to attribute to the growth failure in Turner syndrome. For testing the frequency of defects of SHOX in unexplained growth failure and recombinant human GH (rhGH) as a possible growth-promoting agent, we selected 68 children with idiopathic short stature. These probands had heights below -2.0 SD score for age, normal target heights, no significant bone age retardations, no endocrine abnormalities, no skeletal diseases, and no other organic diseases. No mutations were detected by single-strand conformational polymorphism analysis of the PCR-amplified SHOX. The analysis of three microsatellite DNA markers of the pseudoautosomal region, including one located on the 5' untranslated region of SHOX-exon 1, identified a 15-yr-old girl who carried a mutation in the form of a complete SHOX deletion. This girl who had a normal karyotype presented with mild mesomelic shortening of the forearms and lower legs. We treated two children with short stature on the basis of a SHOX point mutation (C674T) with rhGH at a dose of 1.0 IU/kg body weight-week in accordance with the regimen used in Turner syndrome. During the first 12 months of treatment, these two children (5.9- and 8.4-yr-old) showed an excellent growth spurt with a growth rate of 9.5 and 9.4 cm/yr, respectively. Growth of the lower extremities was weaker than in the trunk and arms. Our data suggest that short stature due to SHOX deletions is not a rare entity. Growth-promoting therapy with rhGH was effective with regard to height gain, but a tendency to disproportionate growth was apparent. In cases of unexplained growth failure, especially if associated with any mild skeletal disproportions

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)

Facilitating aerobic exercise training in older adults with Alzheimer's disease.

PubMed

Yu, Fang; Kolanowski, Ann

2009-01-01

Emerging science suggests that aerobic exercise might modify the pathophysiology of Alzheimer's disease (AD) and improve cognition. However, there are no clinical practice guidelines for aerobic exercise prescription and training in older adults with AD. A few existing studies showed that older adults with AD can participate in aerobic exercise and improve dementia symptoms, but lack adequate descriptions of their aerobic exercise training programs and their clinical applicability. In this paper, we summarize current knowledge about the potential benefits of aerobic exercise in older adults with AD. We then describe the development of a moderate-intensity aerobic exercise program for this population and report results from its initial testing in a feasibility trial completed by two persons with AD. Two older adults with AD completed the aerobic exercise program. Barriers to the program's implementation are described, and methods to improve more wide-spread adoption of such programs and the design of future studies that test them are suggested.

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. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

Moderate Aerobic Training Improves Cardiorespiratory Parameters in Elastase-Induced Emphysema

PubMed Central

Henriques, Isabela; Lopes-Pacheco, Miquéias; Padilha, Gisele A.; Marques, Patrícia S.; Magalhães, Raquel F.; Antunes, Mariana A.; Morales, Marcelo M.; Rocha, Nazareth N.; Silva, Pedro L.; Xisto, Débora G.; Rocco, Patricia R. M.

2016-01-01

Aim: We investigated the therapeutic effects of aerobic training on lung mechanics, inflammation, morphometry and biological markers associated with inflammation, and endothelial cell damage, as well as cardiac function in a model of elastase-induced emphysema. Methods: Eighty-four BALB/c mice were randomly allocated to receive saline (control, C) or 0.1 IU porcine pancreatic elastase (emphysema, ELA) intratracheally once weekly for 4 weeks. After the end of administration period, once cardiorespiratory impairment associated with emphysema was confirmed, each group was further randomized into sedentary (S) and trained (T) subgroups. Trained mice ran on a motorized treadmill, at moderate intensity, 30 min/day, 3 times/week for 4 weeks. Results: Four weeks after the first instillation, ELA animals, compared to C, showed: (1) reduced static lung elastance (Est,L) and levels of vascular endothelial growth factor (VEGF) in lung tissue, (2) increased elastic and collagen fiber content, dynamic elastance (E, in vitro), alveolar hyperinflation, and levels of interleukin-1β and tumor necrosis factor (TNF)-α, and (3) increased right ventricular diastolic area (RVA). Four weeks after aerobic training, ELA-T group, compared to ELA-S, was associated with reduced lung hyperinflation, elastic and collagen fiber content, TNF-α levels, and RVA, as well as increased Est,L, E, and levels of VEGF. Conclusion: Four weeks of regular and moderate intensity aerobic training modulated lung inflammation and remodeling, thus improving pulmonary function, and reduced RVA and pulmonary arterial hypertension in this animal model of elastase-induced emphysema. PMID:27536247

Relationship between aerobic bacteria, salmonellae and Campylobacter on broiler carcasses.

PubMed

Cason, J A; Bailey, J S; Stern, N J; Whittemore, A D; Cox, N A

1997-07-01

Broiler carcasses were removed from commercial processing lines immediately after defeathering, before chilling, and after chilling to determine whether any relationship exists between aerobic bacteria and the human enteropathogens salmonellae and Campylobacter. In two experiments, a whole carcass rinse procedure was used to sample 30 carcasses after defeathering, 90 carcasses before chilling, and 90 carcasses after chilling, for a total of 210 different carcasses. Aerobic bacteria and Campylobacter spp. were enumerated and the incidence of salmonellae was determined. Salmonellae and Campylobacter incidences were 20 and 94%, respectively, for all carcasses sampled. After picking, neither salmonellae-positive nor Campylobacter-positive carcasses had mean aerobic most probable number (MPN) values that were different from carcasses negative for those organisms. Immediately before chilling, aerobic and Campylobacter counts were 7.12 and 5.33 log10 cfu per carcass, respectively. Immersion chilling reduced aerobic counts by approximately 1.8 log and Campylobacter by 1.5 log, with no change in salmonellae-positive carcasses. There was no difference in aerobic or Campylobacter counts between carcasses that were positive or negative for salmonellae at any of the sampling locations, nor was any correlation found between levels of aerobic organisms and Campylobacter. Carcasses with aerobic counts above the mean or more than one standard deviation above the mean also failed to show any correlation. Discriminant analysis indicated error rates as high as 50% when numbers of aerobic bacteria were used to predict incidence of salmonellae or Campylobacter on individual carcasses. Aerobic bacteria are not suitable as index organisms for salmonellae or Campylobacter on broiler carcasses.

Aerobic microbiology and culture sensitivity of head and neck space infection of odontogenic origin

PubMed Central

Shah, Amit; Ramola, Vikas; Nautiyal, Vijay

2016-01-01

Context: Head and neck space infections source, age, gender, tooth involved, fascial spaces involved, microbiological study of aerobic flora, and antibiotic susceptibilities. Aims: The aim of the present study is to identify causative aerobic microorganisms responsible for deep fascial spaces of head and neck infections and evaluate the resistance of antibiotics used in the treatment of such. Settings and Design: Prospective study in 100 patients. Materials and Methods: This prospective study was conducted on 100 patients who reported in the outpatient department and fulfilled the inclusion criteria to study aerobic microbiology and antibiotic sensitivity in head and neck space infection of odontogenic origin. Pus sample was obtained either by aspiration or by swab stick from the involved spaces, and culture and sensitivity tests were performed. Statistical Analysis Used: Chi-square test and level of significance. Results: Result showed aerobic Gram-positive isolates were 73% and aerobic Gram-negative isolates were 18%. Nine percent cases showed no growth. Streptococcus viridans was the highest isolate in 47% cases among Gram-positive bacteria, and in Gram-negative, Klebsiella pneumoniae was the highest isolate of total cases 11%. Amoxicillin showed resistance (48.4%) as compared to other antibiotics such as ceftriaxone, carbenicillin, amikacin, and imipenem had significantly higher sensitivity. Conclusions: Amoxicillin with clavulanic acid showed (64.8%) efficacy for all organisms isolated, whereas ceftriaxone showed (82.4%) efficacy and could be used in odontogenic infections for both Gram-positive and Gram-negative microorganisms. Substitution of third generation cephalosporin for amoxicillin in the empirical management of deep fascial space infections can also be used. Carbenicillin, amikacin, and imipenem showed (93.4%) sensitivity against all microorganisms and should be reserved for more severe infection. Newer and broad-spectrum antibiotics are more

Defect-free high Sn-content GeSn on insulator grown by rapid melting growth.

PubMed

Liu, Zhi; Cong, Hui; Yang, Fan; Li, Chuanbo; Zheng, Jun; Xue, Chunlai; Zuo, Yuhua; Cheng, Buwen; Wang, Qiming

2016-12-12

GeSn is an attractive semiconductor material for Si-based photonics. However, large lattice mismatch between GeSn and Si and the low solubility of Sn in Ge limit its development. In order to obtain high Sn-content GeSn on Si, it is normally grown at low temperature, which would lead to inevitable dislocations. Here, we reported a single-crystal defect-free graded GeSn on insulator (GSOI) stripes laterally grown by rapid melting growth (RMG). The Sn-content reaches to 14.2% at the end of the GSOI stripe. Transmission electron microscopy observation shows the GSOI stripe without stacking fault and dislocations. P-channel pseudo metal-oxide-semiconductor field effect transistors (MOSFETs) and metal-semiconductor-metal (MSM) Schottky junction photodetectors were fabricated on these GSOIs. Good transistor performance with a low field peak hole mobility of 402 cm 2 /Vs is obtained, which indicates a high-quality of this GSOI structure. Strong near-infrared and short-wave infrared optical absorption of the MSM photodetectors at 1550 nm and 2000 nm were observed. Owing to high Sn-content and defect-free, responsivity of 236 mA/W@-1.5 V is achieved at 1550 nm wavelength. In addition, responsivity reaches 154 mA/W@-1.5 V at 2000 nm with the optical absorption layer only 200 nm-thick, which is the highest value reported for GeSn junction photodetectors until now.

Defect-free high Sn-content GeSn on insulator grown by rapid melting growth

PubMed Central

Liu, Zhi; Cong, Hui; Yang, Fan; Li, Chuanbo; Zheng, Jun; Xue, Chunlai; Zuo, Yuhua; Cheng, Buwen; Wang, Qiming

2016-01-01

GeSn is an attractive semiconductor material for Si-based photonics. However, large lattice mismatch between GeSn and Si and the low solubility of Sn in Ge limit its development. In order to obtain high Sn-content GeSn on Si, it is normally grown at low temperature, which would lead to inevitable dislocations. Here, we reported a single-crystal defect-free graded GeSn on insulator (GSOI) stripes laterally grown by rapid melting growth (RMG). The Sn-content reaches to 14.2% at the end of the GSOI stripe. Transmission electron microscopy observation shows the GSOI stripe without stacking fault and dislocations. P-channel pseudo metal-oxide-semiconductor field effect transistors (MOSFETs) and metal-semiconductor-metal (MSM) Schottky junction photodetectors were fabricated on these GSOIs. Good transistor performance with a low field peak hole mobility of 402 cm2/Vs is obtained, which indicates a high-quality of this GSOI structure. Strong near-infrared and short-wave infrared optical absorption of the MSM photodetectors at 1550 nm and 2000 nm were observed. Owing to high Sn-content and defect-free, responsivity of 236 mA/W@-1.5 V is achieved at 1550 nm wavelength. In addition, responsivity reaches 154 mA/W@-1.5 V at 2000 nm with the optical absorption layer only 200 nm-thick, which is the highest value reported for GeSn junction photodetectors until now. PMID:27941825

Defect-free high Sn-content GeSn on insulator grown by rapid melting growth

NASA Astrophysics Data System (ADS)

Liu, Zhi; Cong, Hui; Yang, Fan; Li, Chuanbo; Zheng, Jun; Xue, Chunlai; Zuo, Yuhua; Cheng, Buwen; Wang, Qiming

2016-12-01

GeSn is an attractive semiconductor material for Si-based photonics. However, large lattice mismatch between GeSn and Si and the low solubility of Sn in Ge limit its development. In order to obtain high Sn-content GeSn on Si, it is normally grown at low temperature, which would lead to inevitable dislocations. Here, we reported a single-crystal defect-free graded GeSn on insulator (GSOI) stripes laterally grown by rapid melting growth (RMG). The Sn-content reaches to 14.2% at the end of the GSOI stripe. Transmission electron microscopy observation shows the GSOI stripe without stacking fault and dislocations. P-channel pseudo metal-oxide-semiconductor field effect transistors (MOSFETs) and metal-semiconductor-metal (MSM) Schottky junction photodetectors were fabricated on these GSOIs. Good transistor performance with a low field peak hole mobility of 402 cm2/Vs is obtained, which indicates a high-quality of this GSOI structure. Strong near-infrared and short-wave infrared optical absorption of the MSM photodetectors at 1550 nm and 2000 nm were observed. Owing to high Sn-content and defect-free, responsivity of 236 mA/W@-1.5 V is achieved at 1550 nm wavelength. In addition, responsivity reaches 154 mA/W@-1.5 V at 2000 nm with the optical absorption layer only 200 nm-thick, which is the highest value reported for GeSn junction photodetectors until now.

HRTEM Analysis of Crystallographic Defects in CdZnTe Single Crystal

NASA Astrophysics Data System (ADS)

Yasar, Bengisu; Ergunt, Yasin; Kabukcuoglu, Merve Pinar; Parlak, Mehmet; Turan, Rasit; Kalay, Yunus Eren

2018-01-01

In recent years, CdZnTe has attracted much attention due to its superior electrical and structural properties for room-temperature operable gamma and x-ray detectors. However, CdZnTe (CZT) material has often suffered from crystallographic defects encountered during the growth and post-growth processes. The identification and structural characterization of these defects is crucial to synthesize defect-free CdZnTe single crystals. In this study, Cd0.95 Zn0.05 Te single crystals were grown using a three-zone vertical Bridgman system. The single crystallinity of the material was ensured by using x-ray diffraction measurements. High-resolution electron microscopy (HRTEM) was used to characterize the nano-scale defects on the CdZnTe matrix. The linear defects oriented along the ⟨211⟩ direction were examined by transmission electron microscopy (TEM) and the corresponding HRTEM image simulations were performed by using a quantitative scanning TEM simulation package.

Hydrogen-related defects in hydrogenated amorphous semiconductors

NASA Astrophysics Data System (ADS)

Jin, Shu; Ley, Lothar

1991-07-01

One of the key steps in the formation of glow-discharge-deposited (GD) a-Si:H or a-Ge:H films by plasma deposition from the gas phase is the elimination of excess hydrogen from the growth surface which is necessary for the cross linking of the Si or Ge network and the reduction of the defect density associated with the hydrogen-rich surface layer. The high defect density (~1018 cm-3) in a growing surface layer can, depending on preparation conditions, be either reduced (to ~1016 cm-3) or be trapped in the bulk upon subsequent growth, as evidenced by a great deal of data. However, little is known about its origin and implication. We have investigated the change in electronic structure related with this process using UHV-evaporated a-Ge as a model system, subjected to thermal hydrogenation, plasma hydrogenation, and various annealing cycles. The density of occupied states in the pseudogap of the a-Ge(:H) surface (probing depth ~50 Å) was determined with total-yield photoelectron spectroscopy. In this way, effects of thermal annealing, hydrogenation, and ion bombarding on the near-surface defect density could be studied. We identify in room-temperature (RT) hydrogenated a-Ge:H another defect at about Ev+0.45 eV in addition to the dangling-bond defect. This defect exists at the initial stage of hydrogen incorporation, decreases upon ~250 °C annealing, and is restored upon RT rehydrogenation. Therefore we suspect that this defect is hydrogen induced and concomitant with the formation of unexpected bondings [both multiply bonded XHx (X=Si or Ge and x=2 and 3) and polyhydride (XH2)n configurations] favored at RT hydrogenation. As a possible candidate we suggest the Ge-H-Ge three-center bond in which one electron is placed in a nonbonding orbital that gives rise to the paramagnetic state in the gap of a-Ge:H observed here. This defect also accounts for the large defect density at the growing surface in the optimized plasma chemical-vapor-deposition process, where the

Defective ribosome assembly in Shwachman-Diamond syndrome.

PubMed

Wong, Chi C; Traynor, David; Basse, Nicolas; Kay, Robert R; Warren, Alan J

2011-10-20

Shwachman-Diamond syndrome (SDS), a recessive leukemia predisposition disorder characterized by bone marrow failure, exocrine pancreatic insufficiency, skeletal abnormalities and poor growth, is caused by mutations in the highly conserved SBDS gene. Here, we test the hypothesis that defective ribosome biogenesis underlies the pathogenesis of SDS. We create conditional mutants in the essential SBDS ortholog of the ancient eukaryote Dictyostelium discoideum using temperature-sensitive, self-splicing inteins, showing that mutant cells fail to grow at the restrictive temperature because ribosomal subunit joining is markedly impaired. Remarkably, wild type human SBDS complements the growth and ribosome assembly defects in mutant Dictyostelium cells, but disease-associated human SBDS variants are defective. SBDS directly interacts with the GTPase elongation factor-like 1 (EFL1) on nascent 60S subunits in vivo and together they catalyze eviction of the ribosome antiassociation factor eukaryotic initiation factor 6 (eIF6), a prerequisite for the translational activation of ribosomes. Importantly, lymphoblasts from SDS patients harbor a striking defect in ribosomal subunit joining whose magnitude is inversely proportional to the level of SBDS protein. These findings in Dictyostelium and SDS patient cells provide compelling support for the hypothesis that SDS is a ribosomopathy caused by corruption of an essential cytoplasmic step in 60S subunit maturation.

Impact of isovalent doping on radiation defects in silicon

NASA Astrophysics Data System (ADS)

Londos, C. A.; Sgourou, E. N.; Timerkaeva, D.; Chroneos, A.; Pochet, P.; Emtsev, V. V.

2013-09-01

Isovalent doping is an important process for the control of point defects in Si. Here, by means of infrared spectroscopy, we investigated the properties of the two main radiation-induced defects in Czochralski-Si (Cz-Si) the oxygen-vacancy (VO) and the carbon-oxygen (CiOi) centres. In particular, we investigated the effect of isovalent doping on the production, the thermal evolution, and the thermal stability of the VO and the CiOi defects. Additionally, we studied the reactions that participate upon annealing and the defects formed as a result of these reactions. Upon annealing VO is converted to VO2 defect although part of the CiOi is converted to CsO2i complexes. Thus, we studied the conversion ratios [VO2]/[VO] and [CsO2i]/[CiOi] with respect to the isovalent dopant. Additionally, the role of carbon in the above processes was discussed. A delay between the temperature characterizing the onset of the VO decay and the temperature characterizing the VO2 growth as well the further growth of VO2 after the complete disappearance of VO indicate that the VO to VO2 conversion is a complex phenomenon with many reaction processes involved. Differences exhibited between the effects of the various dopants on the properties of the two defects were highlighted. The results are discussed in view of density functional theory calculations involving the interaction of isovalent dopants with intrinsic defects, the oxygen and carbon impurities in Si.

Application of Potential Phosphate-Solubilizing Bacteria and Organic Acids on Phosphate Solubilization from Phosphate Rock in Aerobic Rice

PubMed Central

Jusop, Shamshuddin; Naher, Umme Aminun; Othman, Radziah; Razi, Mohd Ismail

2013-01-01

A study was conducted at Universiti Putra Malaysia to determine the effect of phosphate-solubilizing bacteria (PSB) and organic acids (oxalic & malic) on phosphate (P) solubilization from phosphate rock (PR) and growth of aerobic rice. Four rates of each organic acid (0, 10, 20, and 30 mM), and PSB strain (Bacillus sp.) were applied to aerobic rice. Total bacterial populations, amount of P solubilization, P uptake, soil pH, and root morphology were determined. The results of the study showed significantly high P solubilization in PSB with organic acid treatments. Among the two organic acids, oxalic acid was found more effective compared to malic acid. Application of oxalic acid at 20 mM along with PSB16 significantly increased soluble soil P (28.39 mg kg−1), plant P uptake (0.78 P pot−1), and plant biomass (33.26 mg). Addition of organic acids with PSB and PR had no influence on soil pH during the planting period. A higher bacterial population was found in rhizosphere (8.78 log10 cfu g−1) compared to the nonrhizosphere and endosphere regions. The application of organic acids along with PSB enhanced soluble P in the soil solution, improved root growth, and increased plant biomass of aerobic rice seedlings without affecting soil pH. PMID:24288473

Genetics Home Reference: abdominal wall defect

MedlinePlus

... are two main types of abdominal wall defects: omphalocele and gastroschisis . Omphalocele is an opening in the center of the ... covering the exposed organs in gastroschisis. Fetuses with omphalocele may grow slowly before birth (intrauterine growth retardation) ...

Characterization of V-shaped defects in 4H-SiC homoepitaxial layers

DOE PAGES

Zhang, Lihua; Su, Dong; Kisslinger, Kim; ...

2014-12-04

Synchrotron white beam x-ray topography images show that faint needle-like surface morphological features observed on the Si-face of 4H-SiC homoepitaxial layers using Nomarski optical microscopy are associated with V shaped stacking faults in the epilayer. KOH etching of the V shaped defect reveals small oval pits connected by a shallow line which corresponding to the surface intersections of two partial dislocations and the stacking fault connecting them. Transmission electron microscopy (TEM) specimens from regions containing the V shaped defects were prepared using focused ion beam milling, and stacking sequences of (85), (50) and (63) are observed at the faulted regionmore » with high resolution TEM. In order to study the formation mechanism of V shaped defect, low dislocation density 4H-SiC substrates were chosen for epitaxial growth, and the corresponding regions before and after epitaxy growth are compared in SWBXT images. It is found that no defects in the substrate are directly associated with the formation of the V shaped defect. Simulation results of the contrast from the two partial dislocations associated with V shaped defect in synchrotron monochromatic beam x-ray topography reveals the opposite sign nature of their Burgers vectors. Therefore, a mechanism of 2D nucleation during epitaxy growth is postulated for the formation of the V shaped defect, which requires elimination of non-sequential 1/4[0001] bilayers from the original structure to create the observed faulted stacking sequence.« less

Characterization of V-shaped defects in 4H-SiC homoepitaxial layers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Lihua; Su, Dong; Kisslinger, Kim

Synchrotron white beam x-ray topography images show that faint needle-like surface morphological features observed on the Si-face of 4H-SiC homoepitaxial layers using Nomarski optical microscopy are associated with V shaped stacking faults in the epilayer. KOH etching of the V shaped defect reveals small oval pits connected by a shallow line which corresponding to the surface intersections of two partial dislocations and the stacking fault connecting them. Transmission electron microscopy (TEM) specimens from regions containing the V shaped defects were prepared using focused ion beam milling, and stacking sequences of (85), (50) and (63) are observed at the faulted regionmore » with high resolution TEM. In order to study the formation mechanism of V shaped defect, low dislocation density 4H-SiC substrates were chosen for epitaxial growth, and the corresponding regions before and after epitaxy growth are compared in SWBXT images. It is found that no defects in the substrate are directly associated with the formation of the V shaped defect. Simulation results of the contrast from the two partial dislocations associated with V shaped defect in synchrotron monochromatic beam x-ray topography reveals the opposite sign nature of their Burgers vectors. Therefore, a mechanism of 2D nucleation during epitaxy growth is postulated for the formation of the V shaped defect, which requires elimination of non-sequential 1/4[0001] bilayers from the original structure to create the observed faulted stacking sequence.« less

Aerobic capacity and its correlates in patients with ankylosing spondylitis.

PubMed

Hsieh, Lin-Fen; Wei, James Cheng-Chung; Lee, Hsin-Yi; Chuang, Chih-Cheng; Jiang, Jiunn-Song; Chang, Kae-Chwen

2016-05-01

To evaluate aerobic capacity in patients with ankylosing spondylitis (AS) and determine possible relationships between aerobic capacity, pulmonary function, and disease-related variables. Forty-two patients with AS and 42 healthy controls were recruited in the study. Descriptive data, disease-related variables (grip strength, lumbosacral mobility, occiput-to-wall distance, chest expansion, finger-to-floor distance, Bath Ankylosing Spondylitis Disease Activity Index, Bath Ankylosing Spondylitis Functional Index (BASFI), Bath Ankylosing Spondylitis Global Score, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and hemoglobin), and chest and thoracic spine x-rays were collected in each patient with AS. All subjects took standard pulmonary function and exercise tolerance tests, and forced vital capacity (FVC) and aerobic capacity were recorded. Both aerobic capacity and FVC in patients with AS were significantly lower than those in normal subjects (P < 0.05). AS patients with BASFI scores of < 3 or BASDI scores of < 4 had a higher aerobic capacity. There was significant correlation between aerobic capacity, vital capacity, chest expansion, Schober's test, cervical range of motion, and BASFI in patients with AS. Neither aerobic capacity nor vital capacity correlated with disease duration, ESR, CRP, and hemoglobin. Significantly reduced aerobic capacity and FVC were observed in patients with AS, and there was significant correlation between aerobic capacity, vital capacity, chest expansion, and BASFI. © 2014 Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty Ltd.

Temperature effects on the aerobic metabolism of glycogen-accumulating organisms.

PubMed

Lopez-Vazquez, Carlos M; Song, Young-Il; Hooijmans, Christine M; Brdjanovic, Damir; Moussa, Moustafa S; Gijzen, Huub J; van Loosdrecht, Mark C M

2008-10-01

Short-term temperature effects on the aerobic metabolism of glycogen-accumulating organisms (GAO) were investigated within a temperature range from 10 to 40 degrees C. Candidatus Competibacter Phosphatis, known GAO, were the dominant microorganisms in the enriched culture comprising 93 +/- 1% of total bacterial population as indicated by fluorescence in situ hybridization (FISH) analysis. Between 10 and 30 degrees C, the aerobic stoichiometry of GAO was insensitive to temperature changes. Around 30 degrees C, the optimal temperature for most of the aerobic kinetic rates was found. At temperatures higher than 30 degrees C, a decrease on the aerobic stoichiometric yields combined with an increase on the aerobic maintenance requirements were observed. An optimal overall temperature for both anaerobic and aerobic metabolisms of GAO appears to be found around 30 degrees C. Furthermore, within a temperature range (10-30 degrees C) that covers the operating temperature range of most of domestic wastewater treatment systems, GAOs aerobic kinetic rates exhibited a medium degree of dependency on temperature (theta = 1.046-1.090) comparable to that of phosphorus accumulating organisms (PAO). We conclude that GAO do not have metabolic advantages over PAO concerning the effects of temperature on their aerobic metabolism, and competitive advantages are due to anaerobic processes.

[Biochemical basis of the single theory of aging. Part II. The cell aerobic status, the hypoxia resistance and proliferation].

PubMed

Kirova, Iu I; Borodulin, V B

2009-01-01

Cells of an organism have different parameters of morphology, metabolism, isoenzyme composition, proliferation and respiration. These differences are derivatives of the cell aerobic status. The primary oxygen acceptors are the "macroscopic" cells (neurons, cardiocytes). In these obligatory aerobic cells oxygen is converted into metabolic water directly by the cytochrome oxidase activity. The secondary oxygen acceptors are the "microscopic" cells (other single-nucleus cells). In these facultative aerobic cells oxygen is converted into hydrogen peroxide. The intracellular labile peroxide pool of oxygen is formed by the oxidase, cytochrome P450, superoxide dismutase, and the mitochondrial cyan-resistance oxidase. The mitochondrial isoenzymes of catalase, glutation peroxidase, and thioredoxin reductase convert hydrogen peroxide into molecular oxygen and form high local oxygen concentration as the major factor for the cytochrome oxidase activity. The hypoxia resistance is increased by the growth of the functional activity of the peroxide-generative and peroxide-mobilizative enzyme systems.

The study of a pilot-scale aerobic/Fenton/anoxic/aerobic process system for the treatment of landfill leachate.

PubMed

Hu, Wenyong; Zhou, Yu; Min, Xiaobo; Liu, Jingyi; Li, Xinyu; Luo, Lin; Zhang, Jiachao; Mao, Qiming; Chai, Liyuan; Zhou, YaoYu

2017-06-29

In this study, a combined aerobic-Fenton-anoxic/aerobic system was designed for the remediation of raw landfill leachate in a pilot-scale experiment. This system included (i) a granular sludge biological oxidation procedure that achieves the accumulation of nitrite nitrogen ([Formula: see text]) under aerobic conditions; (ii) a Fenton process that improves the biodegradability of the biotreated leachate and (iii) an activated sludge biological oxidation component under anoxic and aerobic conditions. Additionally, a shortcut nitrification and denitrification pathway was achieved. The effects of free ammonia, temperature and pH on nitrite accumulation were discussed. The change in the biochemical oxygen demand/chemical oxygen demand ratio of the effluent after shortcut nitrification was also analysed. The microbial community in the reactor were also investigated. The problem of the lack of carbon source in the denitrification process can be solved by the Fenton reagent method. Moreover, it was beneficial to achieving nitrogen removal as well as the more extensive removal of organic matter. The treatment strategy employed in this study exhibited good results and provided the potential practical application for treating landfill leachate.

Minimally invasive treatment of maxillary anterior gingival recession defects by vestibular incision subperiosteal tunnel access and platelet-derived growth factor BB.

PubMed

Zadeh, Homayoun H

2011-01-01

An array of therapeutic options are available for treatment of gingival recession defects, though many of these are better suited for treatment of isolated defects. Some of the limitations of current techniques include the need for harvesting of autogenous donor tissues and their associated morbidity, as well as scar formation at the recipient site resulting from surface incisions. Moreover, muscle pull during healing often leads to incomplete root coverage or relapse of the recession. The current case reports introduce a novel, minimally invasive approach applicable for both isolated recession defects as well as multiple contiguous defects in the maxillary anterior region. Access to the surgical site is obtained by means of an approach referred to as vestibular incision subperiosteal tunnel access (VISTA). This entails making an access incision in the maxillary anterior frenum, followed by elevation of a subperiosteal tunnel. VISTA allows for both access as well as an opportunity to coronally reposition the gingival margins of all involved teeth. In this approach, recombinant human platelet-derived growth factor BB saturated onto a matrix of beta-tricalcium phosphate is introduced using VISTA over root dehiscences to enhance periodontal healing. A novel method of stabilization of the gingival margins is also introduced, referred to as coronally anchored suturing, designed to maintain the coronal positioning during healing. The current report describes the technique and two clinical case documentations for treatment of Miller Class I and II defects, demonstrating stable, long-term outcomes. Although VISTA has been applied in other regions, its application is most advantageous in the esthetic zone.

Treatability of cheese whey for single-cell protein production in nonsterile systems: Part II. The application of aerobic sequencing batch reactor (aerobic SBR) to produce high biomass of Dioszegia sp. TISTR 5792.

PubMed

Monkoondee, Sarawut; Kuntiya, Ampin; Chaiyaso, Thanongsak; Leksawasdi, Noppol; Techapun, Charin; Kawee-Ai, Arthitaya; Seesuriyachan, Phisit

2016-07-03

This study aimed to investigate the efficiency of an aerobic sequencing batch reactor (aerobic SBR) in a nonsterile system using the application of an experimental design via central composite design (CCD). The acidic whey obtained from lactic acid fermentation by immobilized Lactobacillus plantarum sp. TISTR 2265 was fed into the bioreactor of the aerobic SBR in an appropriate ratio between acidic whey and cheese whey to produce an acidic environment below 4.5 and then was used to support the growth of Dioszegia sp. TISTR 5792 by inhibiting bacterial contamination. At the optimal condition for a high yield of biomass production, the system was run with a hydraulic retention time (HRT) of 4 days, a solid retention time (SRT) of 8.22 days, and an acidic whey concentration of 80% feeding. The chemical oxygen demand (COD) decreased from 25,230 mg/L to 6,928 mg/L, which represented a COD removal of 72.15%. The yield of biomass production and lactose utilization by Dioszegia sp. TISTR 5792 were 13.14 g/L and 33.36%, respectively, with a long run of up to 180 cycles and the pH values of effluent were rose up to 8.32 without any pH adjustment.

Improved TNT detoxification by starch addition in a nitrogen-fixing Methylophilus-dominant aerobic microbial consortium.

PubMed

Khan, Muhammad Imran; Lee, Jaejin; Yoo, Keunje; Kim, Seonghoon; Park, Joonhong

2015-12-30

In this study, a novel aerobic microbial consortium for the complete detoxification of 2,4,6-trinitrotoluene (TNT) was developed using starch as a slow-releasing carbon source under nitrogen-fixing conditions. Aerobic TNT biodegradation coupled with microbial growth was effectively stimulated by the co-addition of starch and TNT under nitrogen-fixing conditions. The addition of starch with TNT led to TNT mineralization via ring cleavage without accumulation of any toxic by-products, indicating improved TNT detoxification by the co-addition of starch and TNT. Pyrosequencing targeting the bacterial 16S rRNA gene suggested that Methylophilus and Pseudoxanthomonas population were significantly stimulated by the co-addition of starch and TNT and that the Methylophilus population became predominant in the consortium. Together with our previous study regarding starch-stimulated RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine) degradation (Khan et al., J. Hazard. Mater. 287 (2015) 243-251), this work suggests that the co-addition of starch with a target explosive is an effective way to stimulate aerobic explosive degradation under nitrogen-fixing conditions for enhancing explosive detoxification. Copyright © 2015 Elsevier B.V. All rights reserved.

Treatment of high strength distillery wastewater (cherry stillage) by integrated aerobic biological oxidation and ozonation.

PubMed

Beltrán, F J; Alvarez, P M; Rodríguez, E M; García-Araya, J F; Rivas, J

2001-01-01

The performance of integrated aerobic digestion and ozonation for the treatment of high strength distillery wastewater (i.e., cherry stillage) is reported. Experiments were conducted in laboratory batch systems operating in draw and fill mode. For the biological step, activated sludge from a municipal wastewater treatment facility was used as inoculum, showing a high degree of activity to distillery wastewater. Thus, BOD and COD overall conversions of 95% and 82% were achieved, respectively. However, polyphenol content and absorbance at 254 nm (A(254)) could not be reduced more than 35% and 15%, respectively, by means of single biological oxidation. By considering COD as substrate, the aerobic digestion process followed a Contois' model kinetics, from which the maximum specific growth rate of microorganisms (mu(max)) and the inhibition factor, beta, were then evaluated at different conditions of temperature and pH. In the combined process, the effect of a post-ozonation stage was studied. The main goals achieved by the ozonation step were the removal of polyphenols and A(254). Therefore, ozonation was shown to be an appropriate technology to aid aerobic biological oxidation in the treatment of cherry stillage.

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.

Defect Tolerant Semiconductors for Solar Energy Conversion.

PubMed

Zakutayev, Andriy; Caskey, Christopher M; Fioretti, Angela N; Ginley, David S; Vidal, Julien; Stevanovic, Vladan; Tea, Eric; Lany, Stephan

2014-04-03

Defect tolerance is the tendency of a semiconductor to keep its properties despite the presence of crystallographic defects. Scientific understanding of the origin of defect tolerance is currently missing. Here we show that semiconductors with antibonding states at the top of the valence band are likely to be tolerant to defects. Theoretical calculations demonstrate that Cu3N with antibonding valence band maximum has shallow intrinsic defects and no surface states, in contrast to GaN with bonding valence band maximum. Experimental measurements indicate shallow native donors and acceptors in Cu3N thin films, leading to 10(16)-10(17) cm(-3) doping with either electrons or holes depending on the growth conditions. The experimentally measured bipolar doping and the solar-matched optical absorption onset (1.4 eV) make Cu3N a promising candidate absorber for photovoltaic and photoelectrochemical solar cells, despite the calculated indirect fundamental band gap (1.0 eV). These conclusions can be extended to other materials with antibonding character of the valence band, defining a class of defect-tolerant semiconductors for solar energy conversion applications.

Platelet-Derived Growth Factor Promotes Periodontal Regeneration in Localized Osseous Defects: 36-Month Extension Results From a Randomized, Controlled, Double-Masked Clinical Trial

PubMed Central

Nevins, Myron; Kao, Richard T.; McGuire, Michael K.; McClain, Pamela K.; Hinrichs, James E.; McAllister, Bradley S.; Reddy, Michael S.; Nevins, Marc L.; Genco, Robert J.; Lynch, Samuel E.; Giannobile, William V.

2017-01-01

Background Recombinant human platelet-derived growth factor (rhPDGF) is safe and effective for the treatment of periodontal defects in short-term studies up to 6 months in duration. We now provide results from a 36-month extension study of a multicenter, randomized, controlled clinical trial evaluating the effect and long-term stability of PDGF-BB treatment in patients with localized severe periodontal osseous defects. Methods A total of 135 participants were enrolled fromsix clinical centers for an extension trial. Eighty-three individuals completed the study at 36 months and were included in the analysis. The study investigated the local application of β-tricalcium phosphate scaffold matrix with or without two different dose levels of PDGF (0.3 or 1.0 mg/mL PDGF-BB) in patients possessing one localized periodontal osseous defect. Composite analysis for clinical and radiographic evidence of treatment success was defined as percentage of cases with clinical attachment level (CAL) ≥2.7mmand linear bone growth (LBG) ≥1.1 mm. Results The participants exceeding this composite outcome benchmark in the 0.3 mg/mL rhPDGF-BB group went from 62.2% at 12 months, 75.9% at 24 months, to 87.0% at 36 months compared with 39.5%, 48.3%, and 53.8%, respectively, in the scaffold control group at these same time points (P <0.05). Although there were no significant increases in CAL and LBG at 36 months among all groups, there were continued increases in CAL gain, LBG, and percentage bone fill over time, suggesting overall stability of the regenerative response. Conclusion PDGF-BB in a synthetic scaffold matrix promotes long-term stable clinical and radiographic improvements as measured by composite outcomes for CAL gain and LBG for patients possessing localized periodontal defects (ClinicalTrials.gov no. CT01530126). PMID:22612364

[Factors associated with low levels of aerobic fitness among adolescents].

PubMed

Gonçalves, Eliane Cristina de Andrade; Silva, Diego Augusto Santos

2016-06-01

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. The study included 879 adolescents aged 14 to 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. 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. 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. Copyright © 2015 Sociedade de Pediatria de São Paulo. Publicado por Elsevier Editora Ltda. All rights reserved.

Aerobic Exercise: Top 10 Reasons to Get Physical

MedlinePlus

... can help you live longer and healthier. Need motivation? See how aerobic exercise affects your heart, lungs and blood flow. Then get moving and start reaping the rewards. During aerobic activity, you repeatedly move large muscles ...

Benefits of aerobic exercise after stroke.

PubMed

Potempa, K; Braun, L T; Tinknell, T; Popovich, J

1996-05-01

The debilitating loss of function after a stroke has both primary and secondary effects on sensorimotor function. Primary effects include paresis, paralysis, spasticity, and sensory-perceptual dysfunction due to upper motor neuron damage. Secondary effects, contractures and disuse muscle atrophy, are also debilitating. This paper presents theoretical and empirical benefits of aerobic exercise after stroke, issues relevant to measuring peak capacity, exercise training protocols, and the clinical use of aerobic exercise in this patient population. A stroke, and resulting hemiparesis, produces physiological changes in muscle fibres and muscle metabolism during exercise. These changes, along with comorbid cardiovascular disease, must be considered when exercising stroke patients. While few studies have measured peak exercise capacity in hemiparetic populations, it has been consistently observed in these studies that stroke patients have a lower functional capacity than healthy populations. Hemiparetic patients have low peak exercise responses probably due to a reduced number of motor units available for recruitment during dynamic exercise, the reduced oxidative capacity of paretic muscle, and decreased overall endurance. Consequently, traditional methods to predict aerobic capacity are not appropriate for use with stroke patients. Endurance exercise training is increasingly recognised as an important component in rehabilitation. An average improvement in maximal oxygen consumption (VO2max) of 13.3% in stroke patients who participated in a 10-week aerobic exercise training programme has been reported compared with controls. This study underscored the potential benefits of aerobic exercise training in stroke patients. In this paper, advantages and disadvantages of exercise modalities are discussed in relation to stroke patients. Recommendations are presented to maximise physical performance and minimise potential cardiac risks during exercise.

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,...

Non-destructive Detection of Screw Dislocations and the Corresponding Defects Nucleated from Them During SiC Epitaxial Growth and Their Effect on Device Characteristics

NASA Astrophysics Data System (ADS)

Das, H.; Sunkari, S.; Naas, H.

2018-06-01

In high-volume manufacturing of SiC power devices like Schottky barrier diodes and MOSFETs, especially with the high demands of high reliability applications like the automotive market, the issue of reliability needs to be tackled from multiple angles. It becomes important to isolate and eliminate failure mechanisms at the source rather than just rely on electrical tests. As we enter volume production on 150-mm substrates, an added layer of reliability and improved yield can be added if potential sources of defects are identified and removed. In this work, we present the non-destructive detection of a subset of screw dislocations in N+ doped substrates, trace the preferential nucleation of V-type epitaxial defects and stacking faults from these screw dislocations, and study their electrical effects on Schottky diodes. This enables the screening of highly defective substrates even before committing them to epitaxial growth.

GTL1 and DF1 regulate root hair growth through transcriptional repression of ROOT HAIR DEFECTIVE 6-LIKE 4 in Arabidopsis.

PubMed

Shibata, Michitaro; Breuer, Christian; Kawamura, Ayako; Clark, Natalie M; Rymen, Bart; Braidwood, Luke; Morohashi, Kengo; Busch, Wolfgang; Benfey, Philip N; Sozzani, Rosangela; Sugimoto, Keiko

2018-02-08

How plants determine the final size of growing cells is an important, yet unresolved, issue. Root hairs provide an excellent model system with which to study this as their final cell size is remarkably constant under constant environmental conditions. Previous studies have demonstrated that a basic helix-loop helix transcription factor ROOT HAIR DEFECTIVE 6-LIKE 4 (RSL4) promotes root hair growth, but how hair growth is terminated is not known. In this study, we demonstrate that a trihelix transcription factor GT-2-LIKE1 (GTL1) and its homolog DF1 repress root hair growth in Arabidopsis Our transcriptional data, combined with genome-wide chromatin-binding data, show that GTL1 and DF1 directly bind the RSL4 promoter and regulate its expression to repress root hair growth. Our data further show that GTL1 and RSL4 regulate each other, as well as a set of common downstream genes, many of which have previously been implicated in root hair growth. This study therefore uncovers a core regulatory module that fine-tunes the extent of root hair growth by the orchestrated actions of opposing transcription factors. © 2018. Published by The Company of Biologists Ltd.

GTL1 and DF1 regulate root hair growth through transcriptional repression of ROOT HAIR DEFECTIVE 6-LIKE 4 in Arabidopsis

PubMed Central

Breuer, Christian; Kawamura, Ayako; Clark, Natalie M.; Morohashi, Kengo; Busch, Wolfgang; Benfey, Philip N.; Sozzani, Rosangela

2018-01-01

ABSTRACT How plants determine the final size of growing cells is an important, yet unresolved, issue. Root hairs provide an excellent model system with which to study this as their final cell size is remarkably constant under constant environmental conditions. Previous studies have demonstrated that a basic helix-loop helix transcription factor ROOT HAIR DEFECTIVE 6-LIKE 4 (RSL4) promotes root hair growth, but how hair growth is terminated is not known. In this study, we demonstrate that a trihelix transcription factor GT-2-LIKE1 (GTL1) and its homolog DF1 repress root hair growth in Arabidopsis. Our transcriptional data, combined with genome-wide chromatin-binding data, show that GTL1 and DF1 directly bind the RSL4 promoter and regulate its expression to repress root hair growth. Our data further show that GTL1 and RSL4 regulate each other, as well as a set of common downstream genes, many of which have previously been implicated in root hair growth. This study therefore uncovers a core regulatory module that fine-tunes the extent of root hair growth by the orchestrated actions of opposing transcription factors. PMID:29439132

Forced Aerobic Exercise Preceding Task Practice Improves Motor Recovery Poststroke.

PubMed

Linder, Susan M; Rosenfeldt, Anson B; Dey, Tanujit; Alberts, Jay L

To understand how two types of aerobic exercise affect upper-extremity motor recovery post-stroke. Our aims were to (1) evaluate the feasibility of having people who had a stroke complete an aerobic exercise intervention and (2) determine whether forced or voluntary exercise differentially facilitates upper-extremity recovery when paired with task practice. Seventeen participants with chronic stroke completed twenty-four 90-min sessions over 8 wk. Aerobic exercise was immediately followed by task practice. Participants were randomized to forced or voluntary aerobic exercise groups or to task practice only. Improvement on the Fugl-Meyer Assessment exceeded the minimal clinically important difference: 12.3, 4.8, and 4.4 for the forced exercise, voluntary exercise, and repetitive task practice-only groups, respectively. Only the forced exercise group exhibited a statistically significant improvement. People with chronic stroke can safely complete intensive aerobic exercise. Forced aerobic exercise may be optimal in facilitating motor recovery associated with task practice. Copyright © 2017 by the American Occupational Therapy Association, Inc.

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.

Effects of dominant somatotype on aerobic capacity trainability.

PubMed

Chaouachi, M; Chaouachi, A; Chamari, K; Chtara, M; Feki, Y; Amri, M; Trudeau, F

2005-12-01

This study examined the association between dominant somatotype and the effect on aerobic capacity variables of individualised aerobic interval training. Forty one white North African subjects (age 21.4+/-1.3 years; Vo2max = 52.8+/-5.7 ml kg(-1) min(-1)) performed three exercise tests 1 week apart (i) an incremental test on a cycle ergometer to determine Vo2max and Vo2 at the second ventilatory threshold (VT2); (ii) a VAM-EVAL track test to determine maximal aerobic speed (vVo2max); and (iii) an exhaustive constant velocity test to determine time limit performed at 100% vVo2max (tlim100). Subjects were divided into four somatometric groups: endomorphs-mesomorphs (Endo-meso; n = 9), mesomorphs (Meso; n = 11), mesomorphs-ectomorphs (Meso-ecto; n = 12), and ectomorphs (Ecto; n = 9). Subjects followed a 12 week training program (two sessions/week). Each endurance training session consisted of the maximal number of successive fractions for each subject. Each fraction consisted of one period of exercise at 100% of vVo2max and one of active recovery at 60% of vVo2max. The duration of each period was equal to half the individual tlim100 duration (153.6+/-39.7 s). After the training program, all subjects were re-evaluated for comparison with pre-test results. Pre- and post-training data were grouped by dominant somatotype. Two way ANOVA revealed significant somatotype-aerobic training interaction effects (p<0.001) for improvements in vVo2max, Vo2max expressed classically and according to allometric scaling, and Vo2 at VT2. There were significant differences among groups post-training: the Meso-ecto and the Meso groups showed the greatest improvements in aerobic capacity. The significant somatotype-aerobic training interaction suggests different trainability with intermittent and individualised aerobic training according to somatotype.

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

Surface defect free growth of a spin dimer TlCuCl{sub 3} compound crystals and investigations on its optical and magnetic properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ryu, Gihun, E-mail: G.Ryu@fkf.mpg.de; Son, Kwanghyo

A defect-free high quality single crystal of spin dimer TlCuCl{sub 3} 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{sup −} deficient composition at ≥470 °C. The Cl{sup −}- 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 M{sub b}/M{sub (201)} at 2 K, 7 T=10) using the defect-free TlCuCl{sub 3} crystals in thismore » three-dimensional spin dimer TlCuCl{sub 3} compound, relatively stronger magnetic ordering in the H//b than that of H//(201) direction at above the transition magnetic field. - Graphical abstract: A single crystal of spin dimer TlCuCl{sub 3} compound with a defect free is successfully synthesized on the basis of TG/DTA result. We newly found that this cupric chloride compound is easily decomposed into the Cl{sup −} deficient composition at ≥470 °C and Cl{sup −} related gas phases also give rise to the defects like a pinhole on the surface of TlCuCl{sub 3} crystal. Using the crystals with a surface defect free, we also clearly verified the crystal structure of spin dimer TlCuCl{sub 3} compound.« less

Short communication: Use of a mixture of sodium nitrite, sodium benzoate, and potassium sorbate in aerobically challenged silages.

PubMed

Knicky, Martin; Spörndly, Rolf

2015-08-01

Aerobic instability is still a common problem with many types of silages, particularly well-fermented silages. This study evaluated the effect of adding an additive mixture based on sodium nitrite, sodium benzoate, and potassium sorbate to a variety of crop materials on fermentation quality and aerobic stability of silages. Ensiling conditions were challenged by using a low packing density (104±4.3kg of dry matter/m(3)) of forage and allowing air ingression into silos (at 14 and 7 d before the end of the storage, for 8 h per event). Additive-treated silages were found to have significantly lower pH and reduced formation of ammonia-N, 2.3-butanediol, and ethanol compared with untreated control silages. Yeast growth was significantly reduced by additive treatment in comparison with untreated control silage. Consequently, additive-treated silages were considerably more aerobically stable (6.7 d) than untreated control silages (0.5 d). Overall, adding 5mL/kg of fresh crop of the additive based on sodium nitrite, sodium benzoate, and potassium sorbate reduced undesirable microorganisms in silages and thereby provided suitable ensiling conditions and prolonged aerobic stability, even under air-challenged laboratory ensiling conditions. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Acute aerobic exercise helps overcome emotion regulation deficits.

PubMed

Bernstein, Emily E; McNally, Richard J

2017-06-01

Although colloquial wisdom and some studies suggest an association between regular aerobic exercise and emotional well-being, the nature of this link remains poorly understood. We hypothesised that aerobic exercise may change the way people respond to their emotions. Specifically, we tested whether individuals experiencing difficulties with emotion regulation would benefit from a previous session of exercise and show swifter recovery than their counterparts who did not exercise. Participants (N = 80) completed measures of emotion response tendencies, mood, and anxiety, and were randomly assigned to either stretch or jog for 30 minutes. All participants then underwent the same negative and positive mood inductions, and reported their emotional responses. Analyses showed that more perceived difficulty generating regulatory strategies and engaging in goal-directed behaviours after the negative mood induction predicted more intense and persistent negative affect in response to the stressor, as would be expected. Interactions revealed that aerobic exercise attenuated these effects. Moderate aerobic exercise may help attenuate negative emotions for participants initially experiencing regulatory difficulties. This study contributes to the literature on aerobic exercise's therapeutic effects with experimental data, specifically in the realm of emotional processing.

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.

Anaerobic digestion of dairy cattle manure autoheated by aerobic pretreatment

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 influencingmore » 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.« less

Meta-analysis: aerobic exercise for the treatment of anxiety disorders.

PubMed

Bartley, Christine A; Hay, Madeleine; Bloch, Michael H

2013-08-01

This meta-analysis investigates the efficacy of exercise as a treatment for DSM-IV diagnosed anxiety disorders. We searched PubMED and PsycINFO for randomized, controlled trials comparing the anxiolytic effects of aerobic exercise to other treatment conditions for DSM-IV defined anxiety disorders. Seven trials were included in the final analysis, totaling 407 subjects. The control conditions included non-aerobic exercise, waitlist/placebo, cognitive-behavioral therapy, psychoeducation and meditation. A fixed-effects model was used to calculate the standardized mean difference of change in anxiety rating scale scores of aerobic exercise compared to control conditions. Subgroup analyses were performed to examine the effects of (1) comparison condition; (2) whether comparison condition controlled for time spent exercising and (3) diagnostic indication. Aerobic exercise demonstrated no significant effect for the treatment of anxiety disorders (SMD=0.02 (95%CI: -0.20-0.24), z = 0.2, p = 0.85). There was significant heterogeneity between trials (χ(2) test for heterogeneity = 22.7, df = 6, p = 0.001). The reported effect size of aerobic exercise was highly influenced by the type of control condition. Trials utilizing waitlist/placebo controls and trials that did not control for exercise time reported large effects of aerobic exercise while other trials report no effect of aerobic exercise. Current evidence does not support the use of aerobic exercise as an effective treatment for anxiety disorders as compared to the control conditions. This remains true when controlling for length of exercise sessions and type of anxiety disorder. Future studies evaluating the efficacy of aerobic exercise should employ larger sample sizes and utilize comparison interventions that control for exercise time. Copyright © 2013. Published by Elsevier Inc.

Carbon, nitrogen and phosphorus removal mechanisms of aerobic granules.

PubMed

Sarma, Saurabh Jyoti; Tay, Joo-Hwa

2018-04-10

Aerobic granules are the potential tools to develop modern wastewater treatment technologies with improved nutrient removal efficiency. These granules have several promising advantages over conventional activated sludge-based wastewater treatment processes. This technology has the potential of reducing the infrastructure and operation costs of wastewater treatment by 25%, energy requirement by 30%, and space requirement by 75%. The nutrient removal mechanisms of aerobic granules are slightly different from that of the activated sludge. For instance, unlike activated sludge process, according to some reports, as high as 70% of the total phosphorus removed by aerobic granules were attributed to precipitation within the granules. Similarly, aerobic granule-based technology reduces the total amount of sludge produced during wastewater treatment. However, the reason behind this observation is unknown and it needs further explanations based on carbon and nitrogen removal mechanisms. Thus, as a part of the present review, a set of new hypotheses have been proposed to explain the peculiar nutrient removal mechanisms of the aerobic granules.

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

Effect of cycle time on polyhydroxybutyrate (PHB) production in aerobic mixed cultures.

PubMed

Ozdemir, Sebnem; Akman, Dilek; Cirik, Kevser; Cinar, Ozer

2014-03-01

The aim of this study was to investigate the effect of cycle time on polyhydroxybutyrate (PHB) production under aerobic dynamic feeding system. The acetate-fed feast and famine sequencing batch reactor was used to enrich PHB accumulating microorganism. Sequencing batch reactor (SBR) was operated in four different cycle times (12, 8, 4, and 2 h) fed with a synthetic wastewater. The system performance was determined by monitoring total dissolved organic carbon, dissolved oxygen, oxidation-reduction potential, and PHB concentration. In this study, under steady-state conditions, the feast period of the SBR was found to allow the PHB storage while a certain part of stored PHB was used for continued growth in famine period. The percentage PHB storages by aerobic microorganism were at 16, 18, 42, and 55% for the 12, 8, 4, and 2-h cycle times, respectively. The PHB storage was increased as the length of the cycle time was decreased, and the ratio of the feast compared to the total cycle length was increased from around 13 to 33% for the 12 and 2-h cycle times, respectively.

Metabolic reprogramming during neuronal differentiation from aerobic glycolysis to neuronal oxidative phosphorylation

PubMed Central

Zheng, Xinde; Boyer, Leah; Jin, Mingji; Mertens, Jerome; Kim, Yongsung; Ma, Li; Ma, Li; Hamm, Michael; Gage, Fred H; Hunter, Tony

2016-01-01

How metabolism is reprogrammed during neuronal differentiation is unknown. We found that the loss of hexokinase (HK2) and lactate dehydrogenase (LDHA) expression, together with a switch in pyruvate kinase gene splicing from PKM2 to PKM1, marks the transition from aerobic glycolysis in neural progenitor cells (NPC) to neuronal oxidative phosphorylation. The protein levels of c-MYC and N-MYC, transcriptional activators of the HK2 and LDHA genes, decrease dramatically. Constitutive expression of HK2 and LDHA during differentiation leads to neuronal cell death, indicating that the shut-off aerobic glycolysis is essential for neuronal survival. The metabolic regulators PGC-1α and ERRγ increase significantly upon neuronal differentiation to sustain the transcription of metabolic and mitochondrial genes, whose levels are unchanged compared to NPCs, revealing distinct transcriptional regulation of metabolic genes in the proliferation and post-mitotic differentiation states. Mitochondrial mass increases proportionally with neuronal mass growth, indicating an unknown mechanism linking mitochondrial biogenesis to cell size. DOI: http://dx.doi.org/10.7554/eLife.13374.001 PMID:27282387

Modified chemically defined medium for enhanced respiratory growth of Lactobacillus casei and Lactobacillus plantarum groups.

PubMed

Ricciardi, A; Ianniello, R G; Parente, E; Zotta, T

2015-09-01

Members of the Lactobacillus casei and Lactobacillus plantarum groups are capable of aerobic and respiratory growth. However, they grow poorly in aerobiosis in the currently available chemically defined media, suggesting that aerobic and respiratory growth require further supplementation. The effect of Tween 80, L-alanine, L-asparagine, L-aspartate, L-proline and L-serine on anaerobic and respiratory growth of Lact. casei N87 was investigated using a 2(5) factorial design. The effectiveness of modified CDM (mCDM) was validated on 21 strains of Lact. casei and Lact. plantarum groups. Tween 80 supplementation did not affect anaerobic growth, but improved respiratory growth. L-asparagine, L-proline and L-serine were stimulatory for respiring cells, while the presence of L-aspartate, generally, impaired biomass production. mCDM promoted the growth of Lact. casei and Lact. plantarum, with best results for strains showing a respiratory phenotype. The nutritional requirements of anaerobic and respiratory cultures of members of the Lact. casei and Lact. plantarum groups differ. Tween 80 and selected amino acids derived from pathways related to TCA cycle, pyruvate conversion and NADH recycling are required for respiration. The availability of mCDM will facilitate the study of aerobic metabolism of lactobacilli under controlled conditions. © 2015 The Society for Applied Microbiology.

Viscoelastic shoe insoles: their use in aerobic dancing.

PubMed

Clark, J E; Scott, S G; Mingle, M

1989-01-01

To determine whether use of viscoelastic insoles would significantly decrease the frequency of musculoskeletal overuse injury in aerobic dancers, 139 high-level aerobic dancers were divided randomly into two groups. The control group received placebo foam insoles and test subjects were fitted with viscoelastic insoles. Subjects used these insoles during dance class for 15 weeks. Injury rates were low in both groups and no statistical difference was found. Pain syndromes were fewer in the group using viscoelastic insoles, but the difference was not statistically significant. About a third of dancers fitted with viscoelastic insoles and a tenth of placebo insert wearers found that the insoles made their shoes too tight to be comfortable. No conclusion can be drawn on whether shock-absorbing insoles decrease injuries from aerobic dancing, but use of viscoelastic insoles may improve comfort and provide pain relief for some high-level aerobic dancers if proper fit is achieved.

Evaluation of human recession defects treated with coronally advanced flaps and either purified recombinant human platelet-derived growth factor-BB with beta tricalcium phosphate or connective tissue: a histologic and microcomputed tomographic examination.

PubMed

McGuire, Michael K; Scheyer, Todd; Nevins, Myron; Schupbach, Peter

2009-02-01

The current study examined the histologic and microcomputed tomographic (micro CT) outcomes of the treatment of gingival recession defects with either a subepithelial connective tissue graft (CTG) or 0.3 mg/mL recombinant human platelet-derived growth factor (rhPDGF-BB) on a beta tricalcium phosphate (beta-TCP) matrix. Gingival recession defects were surgically created in six premolar teeth with no more than 3 mm of keratinized marginal tissue, an osseous crest 2 to 3 mm apical to the newly created gingival margin, and recession depth of at least 3 mm. The defects were left untouched for 2 months; then, four defects were grafted with rhPDGF-BB + beta-TCP + a wound healing dressing, and two defects received CTGs. A coronally advanced flap covered each grafted site. Nine months later, sections were obtained for examination. All four sites treated with rhPDGF-BB + beta-TCP showed connective tissue fibers (Sharpey fibers) perpendicularly inserting into newly formed cementum and alveolar bone. In the two sites treated with CTGs, a long junctional epithelium was seen coronal to the osseous crest and connective tissue fibers ran parallel to the adjacent root surfaces, with no evidence of insertion into cementum or bone. There was no evidence of regeneration of cementum, inserting connective tissue fibers, or supporting alveolar bone. Regeneration of the periodontium in gingival recession defects is possible through growth factor-mediated therapy.

[Isolation and identification of electrochemically active microorganism from micro-aerobic environment].

PubMed

Wu, Song; Xiao, Yong; Zheng, Zhi-Yong; Zheng, Yue; Yang, Zhao-Hui; Zhao, Feng

2014-10-01

Extracellular electron transfer of electrochemically active microorganism plays vital role in biogeochemical cycling of metals and carbon and in biosynthesis of bioenergy. Compared to anaerobic anode, micro-aerobic anode captures more energy from microbial fuel cell. However, most of previous researches focused on functioning bacteria in anaerobic anode, functioning bacteria in micro-aerobic anode was rarely studied. Herein, we used the traditional aerobic screening technology to isolate functioning bacteria from a micro-aerobic anode. Three pure cultures Aeromonas sp. WS-XY2, Citrobacter sp. WS-XY3 and Bacterium strain WS-XY4 were obtained. WS-XY2 and WS-XY3 were belonged to Proteobacteria, whereas WS-XY4 was possibly a new species. Cyclic voltammetry and chronoamperometry analysis demonstrated all of them showed the electrochemical activity by direct extracellular electron transfer, and micro-aerobic anode could select bacteria that have similar electrochemical activity to proliferate on the anode. We further conclude that functioning bacteria in micro-aerobic anode are more efficient than that of anaerobic anode may be the reason that micro-aerobic anode has better performance than anaerobic anode. Therefore, a thorough study of functioning bacteria in micro-aerobic anode will significantly promote the energy recovery from microbial fuel cell.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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%; 20more » 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.« less

Defect Characterization in Semiconductors with Positron Annihilation Spectroscopy

NASA Astrophysics Data System (ADS)

Tuomisto, Filip

Positron annihilation spectroscopy is an experimental technique that allows the selective detection of vacancy defects in semiconductors, providing a means to both identify and quantify them. This chapter gives an introduction to the principles of the positron annihilation techniques and then discusses the physics of some interesting observations on vacancy defects related to growth and doping of semiconductors. Illustrative examples are selected from studies performed in silicon, III-nitrides, and ZnO.

Study of low-defect and strain-relaxed GeSn growth via reduced pressure CVD in H2 and N2 carrier gas

NASA Astrophysics Data System (ADS)

Margetis, J.; Mosleh, A.; Al-Kabi, S.; Ghetmiri, S. A.; Du, W.; Dou, W.; Benamara, M.; Li, B.; Mortazavi, M.; Naseem, H. A.; Yu, S.-Q.; Tolle, J.

2017-04-01

High quality, thick (up to 1.1 μm), strain relaxed GeSn alloys were grown on Ge-buffered Si (1 0 0) in an ASM Epsilon® chemical vapor deposition system using SnCl4 and low-cost commercial GeH4 precursors. The significance of surface chemistry in regards to growth rate and Sn-incorporation is discussed by comparing growth kinetics data in H2 and N2 carrier gas. The role of carrier gas is also explored in the suppression of Sn surface segregation and evolution of layer composition and strain profiles via secondary ion mass spectrometry and X-ray diffraction. Transmission electron microscopy revealed the spontaneous compositional splitting and formation of a thin intermediate layer in which dislocations are pinned. This intermediate layer enables the growth of a thick, strain relaxed, and defect-free epitaxial layer on its top. Last, we present photoluminescence results which indicate that both N2 and H2 growth methods produce optoelectronic device quality material.

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

Graded Aerobic Treadmill Testing in Adolescent Traumatic Brain Injury Patients.

PubMed

Cordingley, Dean M; Girardin, Richard; Morissette, Marc P; Reimer, Karen; Leiter, Jeff; Russell, Kelly; Ellis, Michael J

2017-11-01

To examine the safety and tolerability of clinical graded aerobic treadmill testing in recovering adolescent moderate and severe traumatic brain injury (TBI) patients referred to a multidisciplinary pediatric concussion program. We completed a retrospective case series of two moderate and five severe TBI patients (mean age, 17.3 years) who underwent initial Buffalo Concussion Treadmill Testing at a mean time of 71.6 days (range, 55-87) postinjury. Six patients completed one graded aerobic treadmill test each and one patient underwent initial and repeat testing. There were no complications. Five initial treadmill tests were completely tolerated and allowed an accurate assessment of exercise tolerance. Two initial tests were terminated early by the treatment team because of neurological and cardiorespiratory limitations. As a result of testing, two patients were cleared for aerobic exercise as tolerated and four patients were treated with individually tailored submaximal aerobic exercise programs resulting in subjective improvement in residual symptoms and/or exercise tolerance. Repeat treadmill testing in one patient performed after 1 month of treatment with submaximal aerobic exercise prescription was suggestive of improved exercise tolerance. One patient was able to tolerate aerobic exercise following surgery for posterior glottic stenosis. Preliminary results suggest that graded aerobic treadmill testing is a safe, well tolerated, and clinically useful tool to assess exercise tolerance in appropriately selected adolescent patients with TBI. Future prospective studies are needed to evaluate the effect of tailored submaximal aerobic exercise prescription on exercise tolerance and patient outcomes in recovering adolescent moderate and severe TBI patients.

Reduction of Defects in Germanium-Silicon

NASA Technical Reports Server (NTRS)

Szofran, Frank R.; Benz, K. W.; Cobb, Sharon D.; Croell, Anne; Dold, P.; Motafef, S.; Schweizer, M.; Volz, Martin P.; Walker, J. S.

2003-01-01

Crystals grown without being in contact with a container have superior quality to otherwise similar crystals grown in direct contact with a container, especially with respect to impurity incorporation, formation of dislocations, and residual stress in the crystals. In addition to float-zone processing, detached Bridgman growth, although not a completely crucible-free method, is a promising tool to improve crystal quality. It does not suffer from the size limitations of float zoning and the impact of thermocapillary convection on heat and mass transport is expected to be negligible. Detached growth has been observed frequently during g experiments. Considerable improvements in crystalline quality have been reported for these cases. However, neither a thorough understanding of the process nor a quantitative assessment of the quality of these improvements exists. This project will determine the means to reproducibly grow GeSi alloys in a detached mode and seeks to compare processing-induced defects in Bridgman, detached-Bridgman, and floating-zone growth configurations in GeSi crystals (Si less than or equal to 10 at%) up to 20mm in diameter. Specific objectives include: measurement of the relevant material parameters such as contact angle, growth angle, surface tension, and wetting behavior of the GeSi-melt on potential crucible materials; determination of the mechanism of detached growth including the role of convection; quantitative determination of the differences in defects and impurities for crystals grown using normal Bridgman, detached Bridgman, and floating zone (FZ) methods; investigation of the influence of a defined flow imposed by a rotating magnetic field on the characteristics of detached growth; control of time-dependent Marangoni convection in the case of FZ growth by the use of a rotating magnetic field to examine the influence on the curvature of the solid-liquid interface and the heat and mass transport; and growth of benchmark quality Ge

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…

Oxidase catalysis via aerobically generated hypervalent iodine intermediates

NASA Astrophysics Data System (ADS)

Maity, Asim; Hyun, Sung-Min; Powers, David C.

2018-02-01

The development of sustainable oxidation chemistry demands strategies to harness O2 as a terminal oxidant. Oxidase catalysis, in which O2 serves as a chemical oxidant without necessitating incorporation of oxygen into reaction products, would allow diverse substrate functionalization chemistry to be coupled to O2 reduction. Direct O2 utilization suffers from intrinsic challenges imposed by the triplet ground state of O2 and the disparate electron inventories of four-electron O2 reduction and two-electron substrate oxidation. Here, we generate hypervalent iodine reagents—a broadly useful class of selective two-electron oxidants—from O2. This is achieved by intercepting reactive intermediates of aldehyde autoxidation to aerobically generate hypervalent iodine reagents for a broad array of substrate oxidation reactions. The use of aryl iodides as mediators of aerobic oxidation underpins an oxidase catalysis platform that couples substrate oxidation directly to O2 reduction. We anticipate that aerobically generated hypervalent iodine reagents will expand the scope of aerobic oxidation chemistry in chemical synthesis.

Aerobic exercise training for adults with fibromyalgia.

PubMed

Bidonde, Julia; Busch, Angela J; Schachter, Candice L; Overend, Tom J; Kim, Soo Y; Góes, Suelen M; Boden, Catherine; Foulds, Heather Ja

2017-06-21

Exercise training is commonly recommended for individuals with fibromyalgia. This review is one of a series of reviews about exercise training for people with fibromyalgia that will replace the "Exercise for treating fibromyalgia syndrome" review first published in 2002. • To evaluate the benefits and harms of aerobic exercise training for adults with fibromyalgia• To assess the following specific comparisons ० Aerobic versus control conditions (eg, treatment as usual, wait list control, physical activity as usual) ० Aerobic versus aerobic interventions (eg, running vs brisk walking) ० Aerobic versus non-exercise interventions (eg, medications, education) We did not assess specific comparisons involving aerobic exercise versus other exercise interventions (eg, resistance exercise, aquatic exercise, flexibility exercise, mixed exercise). Other systematic reviews have examined or will examine these comparisons (Bidonde 2014; Busch 2013). We searched the Cochrane Library, MEDLINE, Embase, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), the Physiotherapy Evidence Database (PEDro), Thesis and Dissertation Abstracts, the Allied and Complementary Medicine Database (AMED), the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP), and the ClinicalTrials.gov registry up to June 2016, unrestricted by language, and we reviewed the reference lists of retrieved trials to identify potentially relevant trials. We included randomized controlled trials (RCTs) in adults with a diagnosis of fibromyalgia that compared aerobic training interventions (dynamic physical activity that increases breathing and heart rate to submaximal levels for a prolonged period) versus no exercise or another intervention. Major outcomes were health-related quality of life (HRQL), pain intensity, stiffness, fatigue, physical function, withdrawals, and adverse events. Two review authors independently selected trials for inclusion, extracted

Effects of body fat and dominant somatotype on explosive strength and aerobic capacity trainability in prepubescent children.

PubMed

Marta, Carlos C; Marinho, Daniel A; Barbosa, Tiago M; Carneiro, André L; Izquierdo, Mikel; Marques, Mário C

2013-12-01

The purpose of this study was to analyze the influence of body fat and somatotype on explosive strength and aerobic capacity trainability in the prepubertal growth spurt, marked by rapid changes in body size, shape, and composition, all of which are sexually dimorphic. One hundred twenty-five healthy children (58 boys, 67 girls), aged 10-11 years (10.8 ± 0.4 years), who were self-assessed in Tanner stages 1-2, were randomly assigned into 2 experimental groups to train twice a week for 8 weeks: strength training group (19 boys, 22 girls), endurance training group (21 boys, 24 girls), and a control group (18 boys, 21 girls). Evaluation of body fat was carried out using the method described by Slaughter. Somatotype was computed according to the Heath-Carter method. Increased endomorphy reduced the likelihood of vertical jump height improvement (odds ratio [OR], 0.10; 95% confidence interval [CI], 0.01-0.85), increased mesomorphy (OR, 6.15; 95% CI, 1.52-24.88) and ectomorphy (OR, 6.52; 95% CI, 1.71-24.91) increased the likelihood of sprint performance, and increased ectomorphy (OR, 3.84; 95% CI, 1.20-12.27) increased the likelihood of aerobic fitness gains. Sex did not affect the training-induced changes in strength or aerobic fitness. These data suggest that somatotype has an effect on explosive strength and aerobic capacity trainability, which should not be disregarded. The effect of adiposity on explosive strength, musculoskeletal magnitude on running speed, and relative linearity on running speed and aerobic capacity seem to be crucial factors related to training-induced gains in prepubescent boys and girls.

Age Moderates the Association of Aerobic Exercise with Initial Learning of an Online Task Requiring Cognitive Control.

PubMed

O'Connor, Patrick J; Tomporowski, Phillip D; Dishman, Rodney K

2015-11-01

The aim of this study was to examine whether people differed in change in performance across the first five blocks of an online flanker task and whether those trajectories of change were associated with self-reported aerobic or resistance exercise frequency according to age. A total of 8752 men and women aged 13-89 completed a lifestyle survey and five 45-s games (each game was a block of ~46 trials) of an online flanker task. Accuracy of the congruent and incongruent flanker stimuli was analyzed using latent class and growth curve modeling adjusting for time between blocks, whether the blocks occurred on the same or different days, education, smoking, sleep, caffeinated coffee and tea use, and Lumosity training status ("free play" or part of a "daily brain workout"). Aerobic and resistance exercise were unrelated to first block accuracies. For the more cognitively demanding incongruent flanker stimuli, aerobic activity was positively related to the linear increase in accuracy [B=0.577%, 95% confidence interval (CI), 0.112 to 1.25 per day above the weekly mean of 2.8 days] and inversely related to the quadratic deceleration of accuracy gains (B=-0.619% CI, -1.117 to -0.121 per day). An interaction of aerobic activity with age indicated that active participants younger than age 45 had a larger linear increase and a smaller quadratic deceleration compared to other participants. Age moderates the association between self-reported aerobic, but not self-reported resistance, exercise and changes in cognitive control that occur with practice during incongruent presentations across five blocks of a 45-s online, flanker task.

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. © Georg Thieme Verlag KG Stuttgart · New York.

Effects of dominant somatotype on aerobic capacity trainability

PubMed Central

Chaouachi, M; Chaouachi, A; Chamari, K; Chtara, M; Feki, Y; Amri, M; Trudeau, F

2005-01-01

Purpose: This study examined the association between dominant somatotype and the effect on aerobic capacity variables of individualised aerobic interval training. Methods: Forty one white North African subjects (age 21.4±1.3 years; V·o2max = 52.8±5.7 ml kg–1 min–1) performed three exercise tests 1 week apart (i) an incremental test on a cycle ergometer to determine V·o2max and V·o2 at the second ventilatory threshold (VT2); (ii) a VAM-EVAL track test to determine maximal aerobic speed (vV·o2max); and (iii) an exhaustive constant velocity test to determine time limit performed at 100% vV·o2max (tlim100). Subjects were divided into four somatometric groups: endomorphs-mesomorphs (Endo-meso; n = 9), mesomorphs (Meso; n = 11), mesomorphs-ectomorphs (Meso-ecto; n = 12), and ectomorphs (Ecto; n = 9). Subjects followed a 12 week training program (two sessions/week). Each endurance training session consisted of the maximal number of successive fractions for each subject. Each fraction consisted of one period of exercise at 100% of vV·o2max and one of active recovery at 60% of vV·o2max. The duration of each period was equal to half the individual tlim100 duration (153.6±39.7 s). After the training program, all subjects were re-evaluated for comparison with pre-test results. Results: Pre- and post-training data were grouped by dominant somatotype. Two way ANOVA revealed significant somatotype-aerobic training interaction effects (p<0.001) for improvements in vV·o2max, V·o2max expressed classically and according to allometric scaling, and V·o2 at VT2. There were significant differences among groups post-training: the Meso-ecto and the Meso groups showed the greatest improvements in aerobic capacity. Conclusion: The significant somatotype-aerobic training interaction suggests different trainability with intermittent and individualised aerobic training according to somatotype. PMID:16306506

Technical note: enumeration of mesophilic aerobes in milk: evaluation of standard official protocols and Petrifilm aerobic count plates.

PubMed

Freitas, R; Nero, L A; Carvalho, A F

2009-07-01

Enumeration of mesophilic aerobes (MA) is the main quality and hygiene parameter for raw and pasteurized milk. High levels of these microorganisms indicate poor conditions in production, storage, and processing of milk, and also the presence of pathogens. Fifteen raw and 15 pasteurized milk samples were submitted for MA enumeration by a conventional plating method (using plate count agar) and Petrifilm Aerobic Count plates (3M, St. Paul, MN), followed by incubation according to 3 official protocols: IDF/ISO (incubation at 30 degrees C for 72 h), American Public Health Association (32 degrees C for 48 h), and Brazilian Ministry of Agriculture (36 degrees C for 48 h). The results were compared by linear regression and ANOVA. Considering the results from conventional methodology, good correlation indices and absence of significant differences between mean counts were observed, independent of type of milk sample (raw or pasteurized) and incubation conditions (IDF/ISO, American Public Health Association, or Ministry of Agriculture). Considering the results from Petrifilm Aerobic Count plates, good correlation indices and absence of significant differences were only observed for raw milk samples. The microbiota of pasteurized milk interfered negatively with the performance of Petrifilm Aerobic Count plates, probably because of the presence of microorganisms that poorly reduce the dye indicator of this system.

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

Defect mediated van der Waals epitaxy of hexagonal boron nitride on graphene

NASA Astrophysics Data System (ADS)

Heilmann, M.; Bashouti, M.; Riechert, H.; Lopes, J. M. J.

2018-04-01

Van der Waals heterostructures comprising of hexagonal boron nitride and graphene are promising building blocks for novel two-dimensional devices such as atomically thin transistors or capacitors. However, demonstrators of those devices have been so far mostly fabricated by mechanical assembly, a non-scalable and time-consuming method, where transfer processes can contaminate the surfaces. Here, we investigate a direct growth process for the fabrication of insulating hexagonal boron nitride on high quality epitaxial graphene using plasma assisted molecular beam epitaxy. Samples were grown at varying temperatures and times and studied using atomic force microscopy, revealing a growth process limited by desorption at high temperatures. Nucleation was mostly commencing from morphological defects in epitaxial graphene, such as step edges or wrinkles. Raman spectroscopy combined with x-ray photoelectron measurements confirm the formation of hexagonal boron nitride and prove the resilience of graphene against the nitrogen plasma used during the growth process. The electrical properties and defects in the heterostructures were studied with high lateral resolution by tunneling current and Kelvin probe force measurements. This correlated approach revealed a nucleation apart from morphological defects in epitaxial graphene, which is mediated by point defects. The presented results help understanding the nucleation and growth behavior during van der Waals epitaxy of 2D materials, and point out a route for a scalable production of van der Waals heterostructures.

Three-dimensional porous poly-DL-lactide/basic fibroblast growth factor composites for bone defect repair: an experimental study.

PubMed

Min, Shao-xiong; Jin, An-min; Tong, Bin-hui; Zhu, Li-xin; Tian, Jing

2003-04-01

To investigate the osteoinductive ability of the composites consisting of basic fibroblast growth factor (bFGF) and porous poly-DL-lactide (PDLLA) for the development of a new absorbable osteosynthesis material. Highly porous foams of PDLLA with the pore size ranging from 150 to 300 microm were prepared by a solvent-casting, particulate-leaching technique with NaCl as the leachable component. Animal models of radial diaphyseal defects of 1.0 cm with complete removal of the periosteum were induced in 45 rabbits, which were randomly divided into 3 groups to receive the defect repair with PDLLA and PDLLA/bFGF respectively, leaving one group untreated to serve as the control group. The implant specimens were harvested at 2, 4, 8, and 12 weeks respectively after the surgery and X-ray, histological and scanning electron microscopic (SEM) examinations were performed to evaluate the effectiveness of defect repair. At 8 and 12 weeks after implantation, biomechanical test (for three-point bending strength) was employed to study the quality of bone formation. PDLLA/bFGF composite stimulated more bone formation and had higher bending strength than PDLLA (P<0.05), and the bone formation induced by both materials was significantly more than that observed in the control group in every postoperative stage (P<0.05). PDLLA possesses good biocompatibility and absorbability, and when prepared into a porous material, it exhibits good osteoconductibility. As a good bFGF carrier, the foam of PDLLA with three- dimensional structure shows good osteoinductive ability with regard to the rapidity, quantity and quality of the bone formation.

Characterization, modeling and application of aerobic granular sludge for wastewater treatment.

PubMed

Liu, Xian-Wei; Yu, Han-Qing; Ni, Bing-Jie; Sheng, Guo-Ping

2009-01-01

Recently extensive studies have been carried out to cultivate aerobic granular sludge worldwide, including in China. Aerobic granules, compared with conventional activated sludge flocs, are well known for their regular, dense, and strong microbial structure, good settling ability, high biomass retention, and great ability to withstand shock loadings. Studies have shown that the aerobic granules could be applied for the treatment of low- or high-strength wastewaters, simultaneous removal of organic carbon, nitrogen and phosphorus, and decomposition of toxic wastewaters. Thus, this new form of activate sludge, like anaerobic granular sludge, could be employed for the treatment of municipal and industrial wastewaters in near future. This chapter attempts to provide an up-to-date review on the definition, cultivation, characterization, modeling and application of aerobic granular sludge for biological wastewater treatment. This review outlines some important discoveries with regard to the factors affecting the formation of aerobic granular sludge, their physicochemical characteristics, as well as their microbial structure and diversity. It also summarizes the modeling of aerobic granule formation. Finally, this chapter highlights the applications of aerobic granulation technology in the biological wastewater treatment. It is concluded that the knowledge regarding aerobic granular sludge is far from complete. Although previous studies in this field have undoubtedly improved our understanding on aerobic granular sludge, it is clear that much remains to be learned about the process and that many unanswered questions still remain. One of the challenges appears to be the integration of the existing and growing scientific knowledge base with the observations and applications in practice, which this paper hopes to partially achieve.

Characterization, Modeling and Application of Aerobic Granular Sludge for Wastewater Treatment

NASA Astrophysics Data System (ADS)

Liu, Xian-Wei; Yu, Han-Qing; Ni, Bing-Jie; Sheng, Guo-Ping

Recently extensive studies have been carried out to cultivate aerobic granular sludge worldwide, including in China. Aerobic granules, compared with conventional activated sludge flocs, are well known for their regular, dense, and strong microbial structure, good settling ability, high biomass retention, and great ability to withstand shock loadings. Studies have shown that the aerobic granules could be applied for the treatment of low- or high-strength wastewaters, simultaneous removal of organic carbon, nitrogen and phosphorus, and decomposition of toxic wastewaters. Thus, this new form of activate sludge, like anaerobic granular sludge, could be employed for the treatment of municipal and industrial wastewaters in near future. This chapter attempts to provide an up-to-date review on the definition, cultivation, characterization, modeling and application of aerobic granular sludge for biological wastewater treatment. This review outlines some important discoveries with regard to the factors affecting the formation of aerobic granular sludge, their physicochemical characteristics, as well as their microbial structure and diversity. It also summarizes the modeling of aerobic granule formation. Finally, this chapter highlights the applications of aerobic granulation technology in the biological wastewater treatment. It is concluded that the knowledge regarding aerobic granular sludge is far from complete. Although previous studies in this field have undoubtedly improved our understanding on aerobic granular sludge, it is clear that much remains to be learned about the process and that many unanswered questions still remain. One of the challenges appears to be the integration of the existing and growing scientific knowledge base with the observations and applications in practice, which this paper hopes to partially achieve.

Crystal growth of GaAs in space

NASA Technical Reports Server (NTRS)

Gatos, H. C.; Lagowski, J.; Pawlowicz, L. M.; Dabkowski, F.; Li, C. J.

1984-01-01

It is shown that stoichiometry variations in the GaAs melt during growth constitute the most critical parameter regarding defect formations and their interactions; this defect structure determines all relevant characteristics of GaAs. Convection in the melt leads to stoichiometric variations. Growth in axial magnetic fields reduces convection and permits the study of defect structure. In order to control stoichiometry in space and to accommodate expansion during solidification, a partially confined configuration was developed. A triangular prism is employed to contain the growth melt. This configuration permits the presence of the desired vapor phase in contact with the melt for controlling the melt stoichiometry.

Effect of Surface and Defect Chemistry on the Photocatalytic Properties of Intentionally Defect-Rich ZnO Nanorod Arrays.

PubMed

Kegel, Jan; Zubialevich, Vitaly Z; Schmidt, Michael; Povey, Ian M; Pemble, Martyn E

2018-05-30

Due to the abundance of intrinsic defects in zinc oxide (ZnO), the material properties are often governed by same. Knowledge of the defect chemistry has proven to be highly important, especially in terms of the photocatalytic degradation of pollutants. Given the fact that defect-free materials or structures exhibiting only one type of defect are extremely difficult to produce, it is necessary to evaluate what influence various defects may have when present together in the material. In this study, intentionally defect-rich ZnO nanorod (NR) arrays are grown using a simple low-temperature solution-based growth technique. Upon changing the defect chemistry using rapid thermal annealing (RTA) the material properties are carefully assessed and correlated to the resulting photocatalytic properties. Special focus is put on the investigation of these properties for samples showing strong orange photoluminescence (PL). It is shown that intense orange emitting NR arrays exhibit improved dye-degradation rates under UV-light irradiation. Furthermore, strong dye-adsorption has been observed for some samples. This behavior is found to stem from a graphitic surface structure (e.g., shell) formed during RTA in vacuum. Since orange-luminescent samples also exhibit an enhancement of the dye adsorption a possible interplay and synergy of these two defects is elucidated. Additionally, evidence is presented suggesting that in annealed ZnO NRs structural defects may be responsible for the often observed PL emission at 3.31 eV. However, a clear correlation with the photocatalytic properties could not be established for these defects. Building on the specific findings presented here, this study also presents some more general guidelines which, it is suggested, should be employed when assessing the photocatalytic properties of defect-rich ZnO.

Aerobic Exercises for Cognition Rehabilitation following Stroke: A Systematic Review.

PubMed

Zheng, Guohua; Zhou, Wenji; Xia, Rui; Tao, Jing; Chen, Lidian

2016-11-01

Cognitive impairments are highly prevalent in stroke survivors and can substantially affect their physical rehabilitation and quality of life. The management of these impairments currently remains limited, but increasing studies reported the effect of aerobic exercise on cognitive performance in patients suffering from stroke. The purpose of this review was to assess the effects of aerobic exercise on cognitive function following stroke. Seven electronic databases (China National Knowledge Infrastructure [CNKI], Chinese Science and Technology Periodical Database [VIP], Wanfang, China Biology Medicine disc [CBM], Science Citation Index [SCI], EMBASE, and PubMed) were searched from their inception to May 31, 2015, for the effects of aerobic exercise on cognitive ability compared to usual physical activity in stroke survivors. RevMan V5.3 (The Nordic Cochrane Centre) was used to analyze the data and to evaluate the methodological quality of the included studies. Ten eligible studies including 394 participants were identified. Six studies showed that aerobic exercise significantly improved global cognitive ability in stroke survivors. Four studies reported aerobic exercise to be beneficial in improving memory, but only one showed statistical significance. Two studies investigated the effects of aerobic exercise on attention, and one showed a significant improvement. One study reported a significant benefit of aerobic exercise on visuospatial ability in stroke survivors. No adverse events were reported in the included studies. Aerobic exercise may have a positive effect on improving global cognitive ability and a potential benefit on memory, attention, and the visuospatial domain of cognition in stroke survivors. However, further large, rigorously designed trials are needed to confirm these findings. Copyright © 2016 National Stroke Association. Published by Elsevier Inc. All rights reserved.

SDHB downregulation facilitates the proliferation and invasion of colorectal cancer through AMPK functions excluding those involved in the modulation of aerobic glycolysis.

PubMed

Xiao, Zhiming; Liu, Shaojun; Ai, Feiyan; Chen, Xiong; Li, Xiayu; Liu, Rui; Ren, Weiguo; Zhang, Xuemei; Shu, Peng; Zhang, Decai

2018-01-01

Loss-of-function of succinate dehydrogenase-B (SDHB) is a predisposing factor of aerobic glycolysis and cancer progression. Adenosine monophosphate activated protein kinase (AMPK) is involved in the regulation of aerobic glycolysis and the diverse hallmarks of cancer. The present study investigated whether AMPK mediated the regulatory effects of SDHB in aerobic glycolysis and cancer growth. The expression of SDHB and AMPK in colorectal cancer (CRC) and normal tissues was assessed by western blotting. HT-29 CRC cells were used to establish in vitro models of ectopic overexpression and knockdown of SDHB. SDHB was downregulated, while AMPK and phosphorylated-AMPK (Thr172) were upregulated in CRC tissues. Experiments involving the loss- or gain-of-function of SDHB, revealed that this protein negatively regulated AMPK by influencing its expression and activity. However, SDHB and AMPK were identified to suppress lactic acid production in CRC cells, indicating that each had an inhibitory effect on aerobic glycolysis. Therefore, the regulation of aerobic glycolysis by SDHB is unlikely to be mediated via AMPK. SDHB knockdown promoted the viability, migration and invasion of HT-29 cells, whereas inhibition of AMPK demonstrated the opposite effect. SDHB overexpression impaired cell migration and invasion, and this effect was reversed following AMPK activation. These results indicate that AMPK may mediate the effects of SDHB in CRC cell proliferation and migration. In conclusion, SDHB downregulation in CRC cells may increase AMPK activity, which may subsequently facilitate the proliferation and invasion of these cancer cells. However, the regulation of aerobic glycolysis by SDHB may be independent of AMPK. Further studies are warranted to elucidate the mechanism by which SDHB regulates aerobic glycolysis.

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…

Aerobic glycolysis in the human brain is associated with development and neotenous gene expression

PubMed Central

Goyal, Manu S.; Hawrylycz, Michael; Miller, Jeremy A.; Snyder, Abraham Z.; Raichle, Marcus E.

2015-01-01

SUMMARY Aerobic glycolysis (AG), i.e., non-oxidative 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 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

A quantitative PCR assay for aerobic, vinyl chloride- and ethene-assimilating microorganisms in groundwater.

PubMed

Jin, Yang Oh; Mattes, Timothy E

2010-12-01

Vinyl chloride (VC) is a known human carcinogen that is primarily formed in groundwater via incomplete anaerobic dechlorination of chloroethenes. Aerobic, ethene-degrading bacteria (etheneotrophs), which are capable of both fortuitous and growth-linked VC oxidation, could be important in natural attenuation of VC plumes that escape anaerobic treatment. In this work, we developed a quantitative, real-time PCR (qPCR) assay for etheneotrophs in groundwater. We designed and tested degenerate qPCR primers for two functional genes involved in aerobic, growth-coupled VC- and ethene-oxidation (etnC and etnE). Primer specificity to these target genes was tested by comparison to nucleotide sequence databases, PCR analysis of template DNA extracted from isolates and environmental samples, and sequencing of qPCR products obtained from VC-contaminated groundwater. The assay was made quantitative by constructing standard curves (threshold cycle vs log gene copy number) with DNA amplified from Mycobacterium strain JS60, an etheneotrophic isolate. Analysis of groundwater samples from three different VC-contaminated sites revealed that etnC abundance ranged from 1.6 × 10(3) - 1.0 × 10(5) copies/L groundwater while etnE abundance ranged from 4.3 × 10(3) - 6.3 × 10(5) copies/L groundwater. Our data suggest this novel environmental measurement method will be useful for supporting VC bioremediation strategies, assisting in site closure, and conducting microbial ecology studies involving etheneotrophs.

Modelling the growth of Leuconostoc mesenteroides by Artificial Neural Networks.

PubMed

García-Gimeno, R M; Hervás-Martínez, C; Rodríguez-Pérez, R; Zurera-Cosano, G

2005-12-15

The combined effect of temperature (10.5 to 24.5 degrees C), pH level (5.5 to 7.5), sodium chloride level (0.25% to 6.25%) and sodium nitrite level (0 to 200 ppm) on the predicted specific growth rate (Gr), lag-time (Lag) and maximum population density (yEnd) of Leuconostoc mesenteroides under aerobic and anaerobic conditions, was studied using an Artificial Neural Network-based model (ANN) in comparison with Response Surface Methodology (RS). For both aerobic and anaerobic conditions, two types of ANN model were elaborated, unidimensional for each of the growth parameters, and multidimensional in which the three parameters Gr, Lag, and yEnd are combined. Although in general no significant statistical differences were observed between both types of model, we opted for the unidimensional model, because it obtained the lowest mean value for the standard error of prediction for generalisation. The ANN models developed provided reliable estimates for the three kinetic parameters studied; the SEP values in aerobic conditions ranged from between 2.82% for Gr, 6.05% for Lag and 10% for yEnd, a higher degree accuracy than those of the RS model (Gr: 9.54%; Lag: 8.89%; yEnd: 10.27%). Similar results were observed for anaerobic conditions. During external validation, a higher degree of accuracy (Af) and bias (Bf) were observed for the ANN model compared with the RS model. ANN predictive growth models are a valuable tool, enabling swift determination of L. mesenteroides growth parameters.

Longitudinal predictors of aerobic performance in adolescent soccer players.

PubMed

Valente-dos-Santos, João; Coelho-e-Silva, Manuel J; Duarte, João; Figueiredo, António J; Liparotti, João R; Sherar, Lauren B; Elferink-Gemser, Marije T; Malina, Robert M

2012-01-01

The importance of aerobic performance in youth soccer is well established. The aim of the present study was to evaluate the contributions of chronological age (CA), skeletal age (SA), body size, and training to the longitudinal development of aerobic performance in youth male soccer players aged 10 to 18 years. Players (n=83) were annually followed up during 5 years, resulting in an average of 4.4 observations per player. Decimal CA was calculated, and SA, stature, body weight, and aerobic performance were measured once per year. Fat-free mass (FFM) was estimated from age- and gender-specific anthropometric formulas, and annual volume training was recorded. After testing for multicollinearity, multilevel regression modeling was used to analyze the longitudinal data aligned by CA and SA (Model 1 and 2, respectively) and to develop aerobic performance scores. The following equations provide estimations of the aerobic performance for young soccer players: ŷ(Model 1 [deviance from the null model =388.50; P<0.01]) =57.75+9.06×centered CA-0.57×centered CA(2)+0.03×annual volume training and ŷ(Model 2 [deviance from the null model=327.98; P<0.01])=13.03+4.04×centered SA-0.12×centered SA(2)+0.99×FFM+0.03×annual volume training. The development of aerobic performance in young soccer players was found to be significantly related to CA, biological development, and volume of training.

A scanning defect mapping system for semiconductor characterization

NASA Technical Reports Server (NTRS)

Sopori, Bushnan L.

1994-01-01

We have developed an optical scanning system that generates maps of the spatial distributions of defects in single and polycrystalline silicon wafers. This instrument, called Scanning Defect Mapping System, utilizes differences in the scattering characteristics of dislocation etch pits and grain boundaries from a defect-etched sample to identify and count them. This system simultaneously operates in the dislocation mode and the grain boundary (GB) mode. In the 'dislocation mode,' the optical scattering from the etch pits is used to statistically count dislocations, while ignoring the GB's. Likewise, in the 'grain boundary mode' the system only recognizes the local scattering from the GB's to generate grain boundary distributions. The information generated by this instrument is valuable for material quality control, identifying mechanisms of defect generation and the nature of thermal stresses during the crystal growth, and the solar cell process design.

Sludge stabilization through aerobic digestion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hartman, R.B.; Smith, D.G.; Bennett, E.R.

1979-10-01

The aerobic digestion process with certain modifications is evaluated as an alternative for sludge processing capable of developing a product with characteristics required for land application. Environmental conditions, including temperature, solids concentration, and digestion time, that affect the aerobic digestion of a mixed primary sludge-trickling filter humus are investigated. Variations in these parameters that influence the characteristics of digested sludge are determined, and the parameters are optimized to: provide the maximum rate of volatile solids reduction; develop a stable, nonodorous product sludge; and provide the maximum rate of oxidation of the nitrogenous material present in the feed sludge. (3 diagrams,more » 9 graphs, 15 references, 3 tables)« less

Defect control of conventional and anomalous electron transport at complex oxide interfaces

DOE PAGES

Gunkel, F.; Bell, Chris; Inoue, Hisashi; ...

2016-08-30

Using low-temperature electrical measurements, the interrelation between electron transport, magnetic properties, and ionic defect structure in complex oxide interface systems is investigated, focusing on NdGaO 3/SrTiO 3 (100) interfaces. Field-dependent Hall characteristics (2–300 K) are obtained for samples grown at various growth pressures. In addition to multiple electron transport, interfacial magnetism is tracked exploiting the anomalous Hall effect (AHE). These two properties both contribute to a nonlinearity in the field dependence of the Hall resistance, with multiple carrier conduction evident below 30 K and AHE at temperatures ≲10 K. Considering these two sources of nonlinearity, we suggest a phenomenological modelmore » capturing the complex field dependence of the Hall characteristics in the low-temperature regime. Our model allows the extraction of the conventional transport parameters and a qualitative analysis of the magnetization. The electron mobility is found to decrease systematically with increasing growth pressure. This suggests dominant electron scattering by acceptor-type strontium vacancies incorporated during growth. The AHE scales with growth pressure. In conclusion, the most pronounced AHE is found at increased growth pressure and, thus, in the most defective, low-mobility samples, indicating a correlation between transport, magnetism, and cation defect concentration.« less

Behavior of nitrogen removal in an aerobic sponge based moving bed biofilm reactor.

PubMed

Zhang, Xinbo; Song, Zi; Guo, Wenshan; Lu, Yanmin; Qi, Li; Wen, Haitao; Ngo, Huu Hao

2017-12-01

This study aims to investigate the behavior of nitrogen removal in an aerobic sponge based moving bed biofilm reactor by evaluating nitrification and denitrification rates of sponge biocarriers from three aerobic moving bed biofilm reactors (MBBRs) with filling ratios of 10% (R-10), 20% (R-20) and 30% (R-30). Results showed that the highest removal efficiencies of total nitrogen in three reactors were 84.5% (R-10), 93.6% (R-20) and 95.3% (R-30). Correspondingly, simultaneous nitrification and denitrification rate (SND) was 90.9%, 97.6% and 100%, respectively. Although R-20 had the highest attached-growth biomass (AGB) per gram of sponge compared to the other two reactors, R-30 showed the maximum ammonium oxidation rate (AOR) (2.1826±0.0717mgNH 4 + -N/gAGB/h) and denitrification rate (DNR) (5.0852±0.0891mgNO 3 - -N/gAGB/h), followed by R-20 and R-10. These results indicated AOR, DNR and AGB were affected by the filling ratio under the same operation mode. Copyright © 2017 Elsevier Ltd. All rights reserved.

Aerobic granular sludge: a promising technology for decentralised wastewater treatment.

PubMed

Li, Z H; Kuba, T; Kusuda, T

2006-01-01

In order to evaluate the characteristics of aerobic granular sludge, a sequencing batch reactor, feeding with synthetic wastewater at the organic loading rate of 8 kg COD/m3 d, was employed on the laboratory scale. Granules occurred in the reactor within 1 week after the inoculation from conventional flocculent sludge. Aerobic granular sludge was characterised by the outstanding settling properties and considerable contaminates removal efficiencies. The SVI30 values were in the range of 20 to 40 ml g(-1). However, the sludge volume index of short settling time (e.g. SVI10--10 min) is suggested to describe the fast settling properties of aerobic granular sludge. The potential application in the decentralised system is evaluated from the point view of footprint and high bioactivity. The occurrence of sloughing, resulting from the outgrowth of filamentous organisms, would be responsible for the instability of aerobic granules. The starvation phase should therefore be carefully controlled for the maintenance and stability of aerobic granular sludge system.

THE ANTIHYPERTENSIVE EFFECTS OF AEROBIC VERSUS ISOMETRIC HANDGRIP RESISTANCE EXERCISE

PubMed Central

ASH, Garrett I.; TAYLOR, Beth A.; THOMPSON, Paul D.; MACDONALD, Hayley V.; LAMBERTI, Lauren; CHEN, Ming-Hui; FARINATTI, Paulo; KRAEMER, William J.; PANZA, Gregory A.; ZALESKI, Amanda L.; DESHPANDE, Ved; BALLARD, Kevin D.; MUJTABA, Mohammadtokir; WHITE, C. Michael; PESCATELLO, Linda S.

2017-01-01

Aerobic exercise reduces blood pressure (BP) on average 5 to 7 mmHg among those with hypertension; limited evidence suggests similar or even greater BP benefits may result from isometric handgrip (IHG) resistance exercise. We conducted a randomized controlled trial investigating the antihypertensive effects of an acute bout of aerobic compared to IHG exercise in the same individuals. Middle-aged adults (n=27) with prehypertension and obesity randomly completed three experiments: aerobic [60% peak oxygen uptake, 30 minutes]; IHG [30% maximum voluntary contraction, 4x2 minutes bilateral]; and non-exercise control. Subjects were assessed for carotid-femoral pulse wave velocity (PWV) pre and post exercise, and left the laboratory wearing an ambulatory BP monitor. Systolic and diastolic BP (SBP/DBP) were lower after aerobic versus IHG (4.8±1.8/3.1±1.3mmHg, p=0.01/0.04) and control (5.6±1.8/3.6±1.3mmHg, p=0.02/0.04) over the awake hours, with no difference between IHG versus control (p=0.80/0.83). PWV changes following acute exercise did not differ by modality (aerobic increased 0.01±0.21m•s−1, IHG decreased 0.06±0.15m•s−1, control increased 0.25±0.17m•s−1, p>0.05). A subset of participants then completed either 8 weeks of aerobic or IHG training. Awake SBP was lower after versus before aerobic training (7.6±3.1mmHg, p=0.02), while sleep DBP was higher after IHG training (7.7±2.3mmHg, p=0.02). Our findings did not support IHG as antihypertensive therapy but that aerobic exercise should continue to be recommended as the primary exercise modality for its immediate and sustained BP benefits. PMID:27861249

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.

Vacancy Defects as Compensating Centers in Mg-Doped GaN

NASA Astrophysics Data System (ADS)

Hautakangas, S.; Oila, J.; Alatalo, M.; Saarinen, K.; Liszkay, L.; Seghier, D.; Gislason, H. P.

2003-04-01

We apply positron annihilation spectroscopy to identify VN-MgGa complexes as native defects in Mg-doped GaN. These defects dissociate in postgrowth annealings at 500 800 °C. We conclude that VN-MgGa complexes contribute to the electrical compensation of Mg as well as the activation of p-type conductivity in the annealing. The observation of VN-MgGa complexes confirms that vacancy defects in either the N or Ga sublattice are abundant in GaN at any position of the Fermi level during growth, as predicted previously by theoretical calculations.

Exercise Training Reduces Intrathoracic Fat Regardless of Defective Glucose Tolerance

PubMed Central

HONKALA, SANNA M.; MOTIANI, KUMAIL K.; ESKELINEN, JARI-JOONAS; SAVOLAINEN, ANNA; SAUNAVAARA, VIRVA; VIRTANEN, KIRSI A.; LÖYTTYNIEMI, ELIISA; KAPANEN, JUKKA; KNUUTI, JUHANI; KALLIOKOSKI, KARI K.; HANNUKAINEN, JARNA C.

2017-01-01

ABSTRACT Purpose Epicardial (EAT) and pericardial (PAT) fat masses and myocardial triglyceride content (MTC) are enlarged in obesity and insulin resistance. We studied whether the high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) similarly decrease ectopic fat in and around the heart and whether the decrease is similar in healthy subjects and subjects with defective glucose tolerance (DGT). Methods A total of 28 healthy men (body mass index = 20.7–30.0 kg·m−2, age = 40–55 yr) and 16 men with DGT (body mass index = 23.8–33.5 kg·m−2, age = 43–53 yr) were randomized into HIIT and MICT interventions for 2 wk. EAT and PAT were determined by computed tomography and MTC by 1H-MRS. Results At baseline, DGT subjects had impaired aerobic capacity and insulin sensitivity and higher levels of whole body fat, visceral fat, PAT, and EAT (P < 0.05, all) compared with healthy subjects. In the whole group, HIIT increased aerobic capacity (HIIT = 6%, MICT = 0.3%; time × training P = 0.007) and tended to improve insulin sensitivity (HIIT = 24%, MICT = 8%) as well as reduce MTC (HIIT = −42%, MICT = +23%) (time × training P = 0.06, both) more efficiently compared with MICT, and without differences in the training response between the healthy and the DGT subjects. However, both training modes decreased EAT (−5%) and PAT (−6%) fat (time P < 0.05) and not differently between the healthy and the DGT subjects. Conclusion Whole body fat, visceral fat, PAT, and EAT masses are enlarged in DGT. Both HIIT and MICT effectively reduce EAT and PAT in healthy and DGT subjects, whereas HIIT seems to be superior as regards improving aerobic capacity, whole-body insulin sensitivity, and MTC. PMID:28628064

Exercise Training Reduces Intrathoracic Fat Regardless of Defective Glucose Tolerance.

PubMed

Honkala, Sanna M; Motiani, Kumail K; Eskelinen, Jari-Joonas; Savolainen, Anna; Saunavaara, Virva; Virtanen, Kirsi A; Löyttyniemi, Eliisa; Kapanen, Jukka; Knuuti, Juhani; Kalliokoski, Kari K; Hannukainen, Jarna C

2017-07-01

Epicardial (EAT) and pericardial (PAT) fat masses and myocardial triglyceride content (MTC) are enlarged in obesity and insulin resistance. We studied whether the high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) similarly decrease ectopic fat in and around the heart and whether the decrease is similar in healthy subjects and subjects with defective glucose tolerance (DGT). A total of 28 healthy men (body mass index = 20.7-30.0 kg·m, age = 40-55 yr) and 16 men with DGT (body mass index = 23.8-33.5 kg·m, age = 43-53 yr) were randomized into HIIT and MICT interventions for 2 wk. EAT and PAT were determined by computed tomography and MTC by H-MRS. At baseline, DGT subjects had impaired aerobic capacity and insulin sensitivity and higher levels of whole body fat, visceral fat, PAT, and EAT (P < 0.05, all) compared with healthy subjects. In the whole group, HIIT increased aerobic capacity (HIIT = 6%, MICT = 0.3%; time × training P = 0.007) and tended to improve insulin sensitivity (HIIT = 24%, MICT = 8%) as well as reduce MTC (HIIT = -42%, MICT = +23%) (time × training P = 0.06, both) more efficiently compared with MICT, and without differences in the training response between the healthy and the DGT subjects. However, both training modes decreased EAT (-5%) and PAT (-6%) fat (time P < 0.05) and not differently between the healthy and the DGT subjects. Whole body fat, visceral fat, PAT, and EAT masses are enlarged in DGT. Both HIIT and MICT effectively reduce EAT and PAT in healthy and DGT subjects, whereas HIIT seems to be superior as regards improving aerobic capacity, whole-body insulin sensitivity, and MTC.

State of the art of aerobic granulation in continuous flow bioreactors.

PubMed

Kent, Timothy R; Bott, Charles B; Wang, Zhi-Wu

In the wake of the success of aerobic granulation in sequential batch reactors (SBRs) for treating wastewater, attention is beginning to turn to continuous flow applications. This is a necessary step given the advantages of continuous flow treatment processes and the fact that the majority of full-scale wastewater treatment plants across the world are operated with aeration tanks and clarifiers in a continuous flow mode. As in SBRs, applying a selection pressure, based on differences in either settling velocity or the size of the biomass, is essential for successful granulation in continuous flow reactors (CFRs). CFRs employed for aerobic granulation come in multiple configurations, each with their own means of achieving such a selection pressure. Other factors, such as bioaugmentation and hydraulic shear force, also contribute to aerobic granulation to some extent. Besides the formation of aerobic granules, long-term stability of aerobic granules is also a critical issue to be addressed. Inorganic precipitation, special inocula, and various operational optimization strategies have been used to improve granule long-term structural integrity. Accumulated studies reviewed in this work demonstrate that aerobic granulation in CFRs is capable of removing a wide spectrum of contaminants and achieving properties generally comparable to those in SBRs. Despite the notable research progress made toward successful aerobic granulation in lab-scale CFRs, to the best of our knowledge, there are only three full-scale tests of the technique, two being seeded with anammox-supported aerobic granules and the other with conventional aerobic granules; two other process alternatives are currently in development. Application of settling- or size-based selection pressures and feast/famine conditions are especially difficult to implement to these and similar mainstream systems. Future research efforts needs to be focused on the optimization of the granule-to-floc ratio, enhancement of

Alteration in Auxin Homeostasis and Signaling by Overexpression Of PINOID Kinase Causes Leaf Growth Defects in Arabidopsis thaliana

PubMed Central

Saini, Kumud; Markakis, Marios N.; Zdanio, Malgorzata; Balcerowicz, Daria M.; Beeckman, Tom; De Veylder, Lieven; Prinsen, Els; Beemster, Gerrit T. S.; Vissenberg, Kris

2017-01-01

In plants many developmental processes are regulated by auxin and its directional transport. PINOID (PID) kinase helps to regulate this transport by influencing polar recruitment of PIN efflux proteins on the cellular membranes. We investigated how altered auxin levels affect leaf growth in Arabidopsis thaliana. Arabidopsis mutants and transgenic plants with altered PID expression levels were used to study the effect on auxin distribution and leaf development. Single knockouts showed small pleiotropic growth defects. Contrastingly, several leaf phenotypes related to changes in auxin concentrations and transcriptional activity were observed in PID overexpression (PIDOE) lines. Unlike in the knockout lines, the leaves of PIDOE lines showed an elevation in total indole-3-acetic acid (IAA). Accordingly, enhanced DR5-visualized auxin responses were detected, especially along the leaf margins. Kinematic analysis revealed that ectopic expression of PID negatively affects cell proliferation and expansion rates, yielding reduced cell numbers and small-sized cells in the PIDOE leaves. We used PIDOE lines as a tool to study auxin dose effects on leaf development and demonstrate that auxin, above a certain threshold, has a negative affect on leaf growth. RNA sequencing further showed how subtle PIDOE-related changes in auxin levels lead to transcriptional reprogramming of cellular processes. PMID:28659952

Twelve-week combined resistance and aerobic training confers greater benefits than aerobic training alone in nondialysis CKD.

PubMed

Watson, Emma L; Gould, Douglas W; Wilkinson, Thomas J; Xenophontos, Soteris; Clarke, Amy L; Vogt, Barbara Perez; Viana, João L; Smith, Alice C

2018-06-01

There is a growing consensus that patients with chronic kidney disease (CKD) should engage in regular exercise, but there is a lack of formal guidelines. In this report, we determined whether combined aerobic and resistance exercise would elicit superior physiological gains, in particular muscular strength, compared with aerobic training alone in nondialysis CKD. Nondialysis patients with CKD stages 3b-5 were randomly allocated to aerobic exercise {AE, n = 21; 9 men; median age 63 [interquartile range (IQR) 58-71] yr; median estimated glomerular filtration rate (eGFR) 24 (IQR 20-30) ml·min -1 ·1.73 m -2 } or combined exercise [CE, n = 20, 9 men, median age 63 (IQR 51-69) yr, median eGFR 27 (IQR 22-32) ml·min -1 ·1.73 m -2 ], preceded by a 6-wk run-in control period. Patients then underwent 12 wk of supervised AE (treadmill, rowing, or cycling exercise) or CE training (as AE plus leg extension and leg press exercise) performed three times per week. Outcome assessments of knee extensor muscle strength, quadriceps muscle volume, exercise capacity, and central hemodynamics were performed at baseline, following the 6-wk control period, and at the end of the intervention. AE and CE resulted in significant increases in knee extensor strength of 16 ± 19% (mean ± SD; P = 0.001) and 48 ± 37% ( P < 0.001), respectively, which were greater after CE ( P = 0.02). AE and CE resulted in 5 ± 7% ( P = 0.04) and 9 ± 7% ( P < 0.001) increases in quadriceps volume, respectively ( P < 0.001), which were greater after CE ( P = 0.01). Both AE and CE increased distance walked in the incremental shuttle walk test [28 ± 44 m ( P = 0.01) and 32 ± 45 m ( P = 0.01), respectively]. In nondialysis CKD, the addition of resistance exercise to aerobic exercise confers greater increases in muscle mass and strength than aerobic exercise alone.

Ca2+ Requirement for Aerobic Nitrogen Fixation by Heterocystous Blue-Green Algae 1

PubMed Central

Rodríguez, Herminia; Rivas, Joaquín; Guerrero, Miguel G.; Losada, Manuel

1990-01-01

The requirement of Ca2+ for growth and nitrogen fixation has been investigated in two strains of heterocystous blue-green algae (Anabaena sp. and Anabaena ATCC 33047). With combined nitrogen (nitrate or ammonium) or with N2 under microaerobic conditions, Ca2+ was not required for growth, at least in concentrations greater than traces. In contrast, Ca2+ was required as a macronutrient for growth and nitrogen fixation with air as the nitrogen source. Addition of Ca2+ to an aerobic culture without Ca2+ promoted, after a lag of several hours, development of nitrogenase activity and cell growth. Provision of air to a microaerobic culture in the absence of Ca2+ promoted a drastic drop in nitrogenase activity, which rapidly recovered its initial level upon restoration of microaerobic conditions. Development of nitrogenase activity in response to either Ca2+ or low oxygen tension was dependent on de novo protein synthesis. The role of Ca2+ seems to be related to protection of nitrogenase from inactivation, by conferring heterocysts resistance to oxygen. PMID:16667401

Aerobic Physical Activity and the Leadership of Principals

ERIC Educational Resources Information Center

Kiser, Kari

2016-01-01

The purpose of this study was to explore if there was a connection between regular aerobic physical activity and the stress and energy levels of principals as they reported it. To begin the research, the current aerobic physical activity level of principals was discovered. Additionally, the energy and stress levels of the principals who do engage…

A single aerobic exercise session accelerates movement execution but not central processing.

PubMed

Beyer, Kit B; Sage, Michael D; Staines, W Richard; Middleton, Laura E; McIlroy, William E

2017-03-27

Previous research has demonstrated that aerobic exercise has disparate effects on speed of processing and movement execution. In simple and choice reaction tasks, aerobic exercise appears to increase speed of movement execution while speed of processing is unaffected. In the flanker task, aerobic exercise has been shown to reduce response time on incongruent trials more than congruent trials, purportedly reflecting a selective influence on speed of processing related to cognitive control. However, it is unclear how changes in speed of processing and movement execution contribute to these exercise-induced changes in response time during the flanker task. This study examined how a single session of aerobic exercise influences speed of processing and movement execution during a flanker task using electromyography to partition response time into reaction time and movement time, respectively. Movement time decreased during aerobic exercise regardless of flanker congruence but returned to pre-exercise levels immediately after exercise. Reaction time during incongruent flanker trials decreased over time in both an aerobic exercise and non-exercise control condition indicating it was not specifically influenced by exercise. This disparate influence of aerobic exercise on movement time and reaction time indicates the importance of partitioning response time when examining the influence of aerobic exercise on speed of processing. The decrease in reaction time over time independent of aerobic exercise indicates that interpreting pre-to-post exercise changes in behavior requires caution. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

MOCVD growth of gallium nitride with indium surfactant

NASA Astrophysics Data System (ADS)

Won, Dong Jin

In this thesis research, the effect of indium surfactant on Ga-polar and N-polar GaN films grown at 950 °C by MOCVD on various substrates such as Si-face SiC, bulk GaN, Si(111), and C-face SiC was studied to investigate the stress relaxation mechanism, structural, and optical properties of GaN films which were modified by the indium surfactant. The effect of indium surfactant on GaN films grown on SiC was studied first. In the 1.8 microm thick Ga-polar GaN films grown on lattice-mismatched Si-face SiC substrates utilizing indium surfactant at 950 °C, inverted hexagonal pyramid surface defects, so-called V-defects which consist of six (1011) planes, formed at threading dislocations on the GaN surface, which gave rise to the relaxation of compressive misfit stress in an elastic way. Simultaneously, enhanced surface mobility of Ga and N adatoms with indium surfactant lead to improved 2D growth, which may be contradictory to the formation of surface defects like V-defects. In order to find the driving force for V-defect formation in the presence of indium, a nucleation and growth model was developed, taking into consideration the strain, surface, and dislocation energies modified by indium surfactant. This model found that the V-defect formation can be energetically preferred since indium reduces the surface energy of the (1011) plane, which gives rise to the V-defect formation and growth that can overcome the energy barrier at the critical radius of the V-defect. These Ga-polar GaN films were found to be unintentionally doped with Si. Thus, an investigation into the effect of intentional Si doping at a constant TMIn flow rate on GaN films was also performed. Si turned out to be another important factor in the generation of V-defects because Si may be captured at the threading dislocation cores by forming Si -- N bonds, acting as a mask to locally prevent GaN growth. This behavior appeared to assist the initiation of the V-defect which enables V-defects to easily

Enhanced damage resistance and novel defect structure of CrFeCoNi under in situ electron irradiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

He, Mo -Rigen; Wang, Shuai; Jin, Ke

Defect production and growth in CrFeCoNi, a single-phase concentrated solid solution alloy, is characterized using in situ electron irradiation inside a transmission electron microscope operated at 400–1250 kV and 400 °C. All observed defects are interstitial-type, either elliptical Frank loops or polygonal (mostly rhombus) perfect loops. Both forms of loops in CrFeCoNi exhibit a sublinear power law of growth that is > 40 times slower than the linear defect growth in pure Ni. Lastly, this result shows how compositional complexity impacts the production of Frenkel pairs and the agglomeration of interstitials into loops, and, thus, enhances the radiation tolerance.

Enhanced damage resistance and novel defect structure of CrFeCoNi under in situ electron irradiation

DOE PAGES

He, Mo -Rigen; Wang, Shuai; Jin, Ke; ...

2016-07-25

Defect production and growth in CrFeCoNi, a single-phase concentrated solid solution alloy, is characterized using in situ electron irradiation inside a transmission electron microscope operated at 400–1250 kV and 400 °C. All observed defects are interstitial-type, either elliptical Frank loops or polygonal (mostly rhombus) perfect loops. Both forms of loops in CrFeCoNi exhibit a sublinear power law of growth that is > 40 times slower than the linear defect growth in pure Ni. Lastly, this result shows how compositional complexity impacts the production of Frenkel pairs and the agglomeration of interstitials into loops, and, thus, enhances the radiation tolerance.

Combined anaerobic and aerobic digestion for increased solids reduction and nitrogen removal.

PubMed

Novak, John T; Banjade, Sarita; Murthy, Sudhir N

2011-01-01

A unique sludge digestion system consisting of anaerobic digestion followed by aerobic digestion and then a recycle step where thickened sludge from the aerobic digester was recirculated back to the anaerobic unit was studied to determine the impact on volatile solids (VS) reduction and nitrogen removal. It was found that the combined anaerobic/aerobic/anaerobic (ANA/AER/ANA) system provided 70% VS reduction compared to 50% for conventional mesophilic anaerobic digestion with a 20 day SRT and 62% for combined anaerobic/aerobic (ANA/AER) digestion with a 15 day anaerobic and a 5 day aerobic SRT. Total Kjeldahl nitrogen (TKN) removal for the ANA/AER/ANA system was 70% for sludge wasted from the aerobic unit and 43.7% when wasted from the anaerobic unit. TKN removal was 64.5% for the ANA/AER system. Copyright © 2010 Elsevier Ltd. All rights reserved.

Propagation analysis of transverse defects originating at the lower gage corner of rail

DOT National Transportation Integrated Search

1998-12-01

This report describes analyses performed to examine the growth rate of a particular transverse defect that forms in the rail head. The most common transverse defect found in rail, known as the detail fracture, has been studied in previous work. The p...

Germination-defective mutant of Neurospora crassa that responds to siderophores

NASA Technical Reports Server (NTRS)

Charlang, G.; Williams, N. P.

1977-01-01

A conditionally germination-defective mutant of Neurospora crassa has been found to be partially curable by ferricrocin and other siderophores. The mutant conidia rapidly lose their membrane-bound siderophores when suspended in buffer or growth media. Germination is consequently delayed unless large numbers of conidia are present (positive population effect). This indicates that the mutant has a membrane defect involving the siderophore attachment site.

A Study on the Fundamental Mechanism and the Evolutionary Driving Forces behind Aerobic Fermentation in Yeast

PubMed Central

Hagman, Arne; Piškur, Jure

2015-01-01

Baker’s yeast Saccharomyces cerevisiae rapidly converts sugars to ethanol and carbon dioxide at both anaerobic and aerobic conditions. The later phenomenon is called Crabtree effect and has been described in two forms, long-term and short-term effect. We have previously studied under fully controlled aerobic conditions forty yeast species for their central carbon metabolism and the presence of long-term Crabtree effect. We have also studied ten steady-state yeast cultures, pulsed them with glucose, and followed the central carbon metabolism and the appearance of ethanol at dynamic conditions. In this paper we analyzed those wet laboratory data to elucidate possible mechanisms that determine the fate of glucose in different yeast species that cover approximately 250 million years of evolutionary history. We determine overflow metabolism to be the fundamental mechanism behind both long- and short-term Crabtree effect, which originated approximately 125–150 million years ago in the Saccharomyces lineage. The “invention” of overflow metabolism was the first step in the evolution of aerobic fermentation in yeast. It provides a general strategy to increase energy production rates, which we show is positively correlated to growth. The “invention” of overflow has also simultaneously enabled rapid glucose consumption in yeast, which is a trait that could have been selected for, to “starve” competitors in nature. We also show that glucose repression of respiration is confined mainly among S. cerevisiae and closely related species that diverged after the whole genome duplication event, less than 100 million years ago. Thus, glucose repression of respiration was apparently “invented” as a second step to further increase overflow and ethanol production, to inhibit growth of other microbes. The driving force behind the initial evolutionary steps was most likely competition with other microbes to faster consume and convert sugar into biomass, in niches that

A study on the fundamental mechanism and the evolutionary driving forces behind aerobic fermentation in yeast.

PubMed

Hagman, Arne; Piškur, Jure

2015-01-01

Baker's yeast Saccharomyces cerevisiae rapidly converts sugars to ethanol and carbon dioxide at both anaerobic and aerobic conditions. The later phenomenon is called Crabtree effect and has been described in two forms, long-term and short-term effect. We have previously studied under fully controlled aerobic conditions forty yeast species for their central carbon metabolism and the presence of long-term Crabtree effect. We have also studied ten steady-state yeast cultures, pulsed them with glucose, and followed the central carbon metabolism and the appearance of ethanol at dynamic conditions. In this paper we analyzed those wet laboratory data to elucidate possible mechanisms that determine the fate of glucose in different yeast species that cover approximately 250 million years of evolutionary history. We determine overflow metabolism to be the fundamental mechanism behind both long- and short-term Crabtree effect, which originated approximately 125-150 million years ago in the Saccharomyces lineage. The "invention" of overflow metabolism was the first step in the evolution of aerobic fermentation in yeast. It provides a general strategy to increase energy production rates, which we show is positively correlated to growth. The "invention" of overflow has also simultaneously enabled rapid glucose consumption in yeast, which is a trait that could have been selected for, to "starve" competitors in nature. We also show that glucose repression of respiration is confined mainly among S. cerevisiae and closely related species that diverged after the whole genome duplication event, less than 100 million years ago. Thus, glucose repression of respiration was apparently "invented" as a second step to further increase overflow and ethanol production, to inhibit growth of other microbes. The driving force behind the initial evolutionary steps was most likely competition with other microbes to faster consume and convert sugar into biomass, in niches that were semi-anaerobic.

Defect-induced magnetism in cobalt-doped ZnO epilayers

NASA Astrophysics Data System (ADS)

Ciatto, G.; Di Trolio, A.; Fonda, E.; Alippi, P.; Polimeni, A.; Capizzi, M.; Varvaro, G.; Bonapasta, A. Amore

2014-02-01

We used a synergic Co-edge X-ray absorption spectroscopy (XAS) and density functional theory calculations approach to perform a study of defects which could account for the room temperature ferromagnetism of ZnCoO, an oxide of great potential interest in semiconductor spintronics. Our results suggest that a key role is played by specific defect complexes in which O vacancies are located close to the Co atoms. Extended defects such as Co clusters have a marginal function, although we observe their formation at the epilayer surface under certain growth conditions. We also show preliminary results of the study of hydrogen-induced defects in ZnCoO epilayers deliberately hydrogen irradiated via a Kaufman source. Hydrogen was in fact predicted to mediate a ferromagnetic spin-spin interaction between neighboring magnetic impurities.

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

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

2015-07-10

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. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

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…

Temporal proteomic analysis reveals defects in small-intestinal development of porcine fetuses with intrauterine growth restriction.

PubMed

Wang, Xiaoqiu; Lin, Gang; Liu, Chuang; Feng, Cuiping; Zhou, Huaijun; Wang, Taiji; Li, Defa; Wu, Guoyao; Wang, Junjun

2014-07-01

The fetus/neonate with intrauterine growth restriction (IUGR) has a high perinatal mortality and morbidity rate, as well as reduced efficiency for nutrients utilization. Our previous studies showed alterations of intestinal proteome in IUGR piglets both at birth and during the nursing period. Considering the potential long-term impacts of fetal programming and substantial increases in amounts of amniotic fluid nutrients from mid-gestation in pigs, the present study involved IUGR porcine fetuses from days 60 to 110 of gestation (mid to late gestation). We identified 59 differentially expressed proteins in the fetal small intestine that are related to intestinal growth, development and reprogramming. Our results further indicated increased abundances of proteins and enzymes associated with oxidative stress, apoptosis and protein degradation, as well as decreased abundances of proteins that are required for maintenance of cell structure and motility, absorption and transport of nutrients, energy metabolism, and protein synthesis in the fetal gut. Moreover, IUGR from middle to late gestation was associated with reduced expression of intestinal proteins that participate in regulation of gene expression and signal transduction. Collectively, these findings provide the first evidence for altered proteomes in the small intestine of IUGR fetuses, thereby predisposing the gut to metabolic defects during gestation and neonatal periods. Copyright © 2014 Elsevier Inc. All rights reserved.

The Study of Cognitive Change Process on Depression during Aerobic Exercises.

PubMed

Sadeghi, Kheirollah; Ahmadi, Seyed Mojtaba; Moghadam, Arash Parsa; Parvizifard, Aliakbar

2017-04-01

Several studies have shown that aerobic exercise is effective in treating the depression and improving the mental health. There are various theories which explains why aerobic exercise is effective in the treatment of depression and improve mental health, but there are limited studies to show how cognitive components and depression improve during aerobic exercises. The current study was carried out to investigate the cognitive change process during aerobic exercises in depressed students. This study was conducted through structural equation modeling; the study sample included 85 depressed students. Participants were selected through purposive sampling method. Beck Depression Inventory (BDI-II), Automatic Negative Thoughts (ATQ), and the Dysfunctional Attitude Scale (DAS) were used as the data collection instruments. The participants received eight sessions of aerobic exercise (three times a week). The obtained data was analysed by AMOS-18 & SPSS 18 software. The results showed that depression (p=0.001), automatic thoughts (ferquency p=0.413, beliefs p=0.676) and dysfunctional assumptions (p=0.219) reduce during aerobic exercise; however, it was only meaningful for the depression. The casual and consequential models were not fit to the data and partially and fully interactive models provided an adequate fit to the data. Fully interactive model provided the best fit of the data. It seems that aerobic exercise reduced cognitive components separately leading to reduce depression.

RETRACTED: Aerobic degradation of 4-nitroaniline (4-NA) via novel degradation intermediates by Rhodococcus sp. strain FK48.

PubMed

Khan, Fazlurrahman; Pandey, Janmejay; Vikram, Surendra; Pal, Deepika; Cameotra, Swaranjit Singh

2013-06-15

An aerobic strain, Rhodococcus sp. strain FK48, capable of growing on 4-nitroaniline (4-NA) as the sole source of carbon, nitrogen, and energy has been isolated from enrichment cultures originating from contaminated soil samples. During growth studies with non- induced cells of FK48 catalyzed sequential denitrification (release of NO₂ substituent) and deamination (release of NH₂ substituent) of 4-NA. However, none of the degradation intermediates could be identified with growth studies. During resting cell studies, 4-NA-induced cells of strain FK48 transformed 4-NA via a previously unknown pathway which involved oxidative hydroxylation leading to formation of 4-aminophenol (4-AP). Subsequent degradation involved oxidated deamination of 4-AP and formation of 1,2,4-benzenetriol (BT) as the major identified terminal aromatic intermediate. Identification of these intermediates was ascertained by HPLC, and GC-MS analyses of the culture supernatants. 4-NA-induced cells of strain FK48 showed positive activity for 1,2,4-benzenetriol dioxygenase in spectrophotometric assay. This is the first conclusive study on aerobic microbial degradation of 4-NA and elucidation of corresponding metabolic pathway. Copyright © 2013 Elsevier B.V. All rights reserved.

Comparative study of the in vitro activity of various antifungal drugs against Scedosporium spp. in aerobic and hyperbaric atmosphere versus normal atmosphere.

PubMed

Farina, C; Marchesi, G; Passera, M; Diliberto, C; Russello, G

2012-06-01

Scedosporium spp. have been observed with increasing frequency over the last decade in immunocompromised patients and trauma patients. This mould is often multi-drug resistant and its mortality rate remains very high. The primary goal of this study was to obtain data concerning the in vitro susceptibility of 13 Scedosporium strains comparing the in vitro incubation in aerobic versus hyperbaric conditions. Chemosensitivity of thirteen Scedosporium strains was evaluated after a 72h-incubation in a normoxic (21% O2) normobaric (1 ATA) atmosphere versus a hyperoxic (100% O2) hyperbaric (2-3 ATA), and after a re-incubation at room temperature for an additional 72h. All S. apiospermum and S. prolificans strains showed no growth after incubation in hyperbaric hyperoxic atmosphere. However, when plates were then maintained at room temperature in aerobic conditions, growth was systematically observed from 36 to 96h, and Minimal inhibitory concentration (MIC) values were the same obtained after incubation in aerobic conditions. These results suggest impressive in vitro fungistatic activity of the hyperoxic hyperbaric atmosphere, even if its effect is strictly time-dependent. This preliminary in vitro study has potential clinical relevance because it focuses on examining in vitro combination therapy using hyperoxic hyperbaric conditions plus a single antifungal agent, rather than using combinations of different antifungal drugs, to potentially increase the antifungal activity. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anzai, Jun, E-mail: anzai_jun@kaken.co.jp; Department of Periodontology, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka 565-0871; Kitamura, Masahiro, E-mail: kitamura@dent.osaka-u.ac.jp

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 periodontalmore » 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

Near Infrared Emission from Defects in Few-Layer Phosphorene

NASA Astrophysics Data System (ADS)

Aghaeimeibodi, Shahriar; Kim, Je-Hyung; Waks, Edo

Atomically thin films of black phosphorus have recently received significant attention as low dimensional optical materials with a direct exciton emission whose wavelength is tunable by controlling the number of layers. In addition to this excitonic emission, recent work has revealed emission from defect states and reported new methods to manipulate them. Monolayer phosphorene exhibits emission from localized defect states at wavelengths near 920 nm. Increasing the number of layers should shift defect emission to longer wavelengths, enabling the material to span a broader spectral range. But defect emission from few-layer phosphorene has not yet been reported. Here, we demonstrate a new class of near infrared defects in few layer phosphorene. Photoluminescence measurement shows a bright emission around 1240 nm with a sublinear growth of emission intensity with linear increase of excitation intensity, confirming the defect nature of this emission. From time-resolved lifetime measurements we determine an emission lifetime of 1.2 ns, in contrast to exciton and trion lifetimes from few layer phosphorene previously reported to be in the range of a few hundred picoseconds. This work highlights the potential of bright defects of phosphorene for near infrared optoelectronic applications.

Concurrent aerobic plus resistance exercise versus aerobic exercise alone to improve health outcomes in paediatric obesity: a systematic review and meta-analysis.

PubMed

García-Hermoso, Antonio; Ramírez-Vélez, Robinson; Ramírez-Campillo, Rodrigo; Peterson, Mark D; Martínez-Vizcaíno, Vicente

2018-02-01

To determine if the combination of aerobic and resistance exercise is superior to aerobic exercise alone for the health of obese children and adolescents. Systematic review with meta-analysis. Computerised search of 3 databases (MEDLINE, EMBASE, and Cochrane Controlled Trials Registry). Studies that compared the effect of supervised concurrent exercise versus aerobic exercise interventions, with anthropometric and metabolic outcomes in paediatric obesity (6-18 years old). The mean differences (MD) of the parameters from preintervention to postintervention between groups were pooled using a random-effects model. 12 trials with 555 youths were included in the meta-analysis. Compared with aerobic exercise alone, concurrent exercise resulted in greater reductions in body mass (MD=-2.28 kg), fat mass (MD=-3.49%; and MD=-4.34 kg) and low-density lipoprotein cholesterol (MD=-10.20 mg/dL); as well as greater increases in lean body mass (MD=2.20 kg) and adiponectin level (MD=2.59 μg/mL). Differences were larger for longer term programmes (>24 weeks). Concurrent aerobic plus resistance exercise improves body composition, metabolic profiles, and inflammatory state in the obese paediatric population. CRD42016039807. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Effect of oxygen on the growth and biofilm formation of Xylella fastidiosa in liquid media.

PubMed

Shriner, Anthony D; Andersen, Peter C

2014-12-01

Xylella fastidiosa is a xylem-limited bacterial pathogen, and is the causative agent of Pierce's disease of grapevines and scorch diseases of many other plant species. The disease symptoms are putatively due to blocking of the transpiration stream by bacterial-induced biofilm formation and/or by the formation of plant-generated tylosis. Xylella fastidiosa has been classified as an obligate aerobe, which appears unusual given that dissolved O2 levels in the xylem during the growing season are often hypoxic (20-60 μmol L(-1)). We examined the growth and biofilm formation of three strains of X. fastidiosa under variable O2 conditions (21, 2.1, 0.21 and 0 % O2), in comparison to that of Pseudomonas syringae (obligate aerobe) and Erwinia carotovora (facultative anaerobe) under similar conditions. The growth of X. fastidiosa more closely resembled that of the facultative anaerobe, and not the obligate aerobe. Xanthomonas campestris, the closest genetic relative of X. fastidiosa, exhibited no growth in an N2 environment, whereas X. fastidiosa was capable of growing in an N2 environment in PW(+), CHARDS, and XDM2-PR media. The magnitude of growth and biofilm formation in the N2 (0 % O2) treatment was dependent on the specific medium. Additional studies involving the metabolism of X. fastidiosa in response to low O2 are warranted. Whether X. fastidiosa is classified as an obligate aerobe or a facultative anaerobe should be confirmed by gene activation and/or the quantification of the metabolic profiles under hypoxic conditions.

Chloride-associated adaptive response in aerobic methylotrophic dichloromethane-utilising bacteria.

PubMed

Torgonskaya, Maria L; Doronina, Nina V; Hourcade, Edith; Trotsenko, Yuri A; Vuilleumier, Stéphane

2011-06-01

Aerobic methylotrophic bacteria able to grow with dichloromethane (DCM) as the sole carbon and energy source possess a specific glutathione S-transferase, DCM dehalogenase, which transforms DCM to formaldehyde, used for biomass and energy production, and hydrochloric acid, which is excreted. Evidence is presented for chloride-specific responses for three DCM-degrading bacteria, Methylobacterium extorquens DM4, Methylopila helvetica DM6 and Albibacter methylovorans DM10. Chloride release into the medium was inhibited by sodium azide and m -chlorophenylhydrazone, suggesting an energy-dependent process. In contrast, only nigericin affected chloride excretion in Mb. extorquens DM4 and Mp. helvetica DM6, while valinomycin had the same effect in A. methylovorans DM10 only. Chloride ions stimulated DCM-dependent induction of DCM dehalogenase expression for Mp. helvetica DM6 and A. methylovorans DM10, and shortened the time for onset of chloride release into the medium. Striking chloride-containing structures were observed by electron microscopy and X-ray microanalysis on the cell surface of Mp. helvetica DM6 and A. methylovorans DM10 during growth with DCM, and with methanol in medium supplemented with sodium chloride. Taken together, these data suggest the existence of both general and specific chloride-associated adaptations in aerobic DCM-degrading bacteria. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A sharp interface model for void growth in irradiated materials

NASA Astrophysics Data System (ADS)

Hochrainer, Thomas; El-Azab, Anter

2015-03-01

A thermodynamic formalism for the interaction of point defects with free surfaces in single-component solids has been developed and applied to the problem of void growth by absorption of point defects in irradiated metals. This formalism consists of two parts, a detailed description of the dynamics of defects within the non-equilibrium thermodynamic frame, and the application of the second law of thermodynamics to provide closure relations for all kinetic equations. Enforcing the principle of non-negative entropy production showed that the description of the problem of void evolution under irradiation must include a relationship between the normal fluxes of defects into the void surface and the driving thermodynamic forces for the void surface motion; these thermodynamic forces are identified for both vacancies and interstitials and the relationships between these forces and the normal point defect fluxes are established using the concepts of transition state theory. The latter theory implies that the defect accommodation into the surface is a thermally activated process. Numerical examples are given to illustrate void growth dynamics in this new formalism and to investigate the effect of the surface energy barriers on void growth. Consequences for phase field models of void growth are discussed.

Implementation of Aerobic Programs.

ERIC Educational Resources Information Center

American Alliance for Health, Physical Education, Recreation and Dance (AAHPERD).

This information is intended for health professionals interested in implementing aerobic exercise programs in public schools, institutions of higher learning, and business and industry workplaces. The papers are divided into three general sections. The introductory section presents a basis for adhering to a health fitness lifestyle, using…

Point defect reduction in MOCVD (Al)GaN by chemical potential control and a comprehensive model of C incorporation in GaN

NASA Astrophysics Data System (ADS)

Reddy, Pramod; Washiyama, Shun; Kaess, Felix; Kirste, Ronny; Mita, Seiji; Collazo, Ramon; Sitar, Zlatko

2017-12-01

A theoretical framework that provides a quantitative relationship between point defect formation energies and growth process parameters is presented. It enables systematic point defect reduction by chemical potential control in metalorganic chemical vapor deposition (MOCVD) of III-nitrides. Experimental corroboration is provided by a case study of C incorporation in GaN. The theoretical model is shown to be successful in providing quantitative predictions of CN defect incorporation in GaN as a function of growth parameters and provides valuable insights into boundary phases and other impurity chemical reactions. The metal supersaturation is found to be the primary factor in determining the chemical potential of III/N and consequently incorporation or formation of point defects which involves exchange of III or N atoms with the reservoir. The framework is general and may be extended to other defect systems in (Al)GaN. The utility of equilibrium formalism typically employed in density functional theory in predicting defect incorporation in non-equilibrium and high temperature MOCVD growth is confirmed. Furthermore, the proposed theoretical framework may be used to determine optimal growth conditions to achieve minimum compensation within any given constraints such as growth rate, crystal quality, and other practical system limitations.

Intrinsic aerobic capacity sets a divide for aging and longevity

PubMed Central

Koch, Lauren Gerard; Kemi, Ole J.; Qi, Nathan; Leng, Sean X.; Bijma, Piter; Gilligan, Lori J.; Wilkinson, John E.; Wisløff, Helene; Høydal, Morten A.; Rolim, Natale; Abadir, Peter M.; Van Grevenhof, Ilse; Smith, Godfrey L.; Burant, Charles F.; Ellingsen, Øyvind; Britton, Steven L.; Wisløff, Ulrik

2011-01-01

Rationale Low aerobic exercise capacity is a powerful predictor of premature morbidity and mortality for healthy adults as well as those with cardiovascular disease For aged populations, poor performance on treadmill or extended walking tests indicates closer proximity to future health declines. Together, these findings suggest a fundamental connection between aerobic capacity and longevity. Objectives Through artificial selective breeding, we developed an animal model system to prospectively test the association between aerobic exercise capacity and survivability (aerobic hypothesis). Methods and Results Laboratory rats of widely diverse genetic backgrounds (N:NIH stock) were selectively bred for low or high intrinsic (inborn) treadmill running capacity. Cohorts of male and female rats from generations 14, 15 and 17 of selection were followed for survivability and assessed for age-related declines in cardiovascular fitness including maximal oxygen uptake (VO2max), myocardial function, endurance performance, and change in body mass. Median lifespan for low exercise capacity rats was 28-45% shorter than high capacity rats (hazard ratio, 0.06; P<.001). VO2max, measured across adulthood was a reliable predictor of lifespan (P<.001). During progression from adult to old age, left ventricular myocardial and cardiomyocyte morphology, contractility, and intracellular Ca2+ handling in both systole and diastole, as well as mean blood pressure, were more compromised in rats bred for low aerobic capacity. Physical activity levels, energy expenditure (VO2), and lean body mass were all better sustained with age in rats bred for high aerobic capacity. Conclusions These data obtained from a contrasting heterogeneous model system provide strong evidence that genetic segregation for aerobic exercise capacity can be linked with longevity and useful for deeper mechanistic exploration. PMID:21921265

Intrinsic aerobic capacity sets a divide for aging and longevity.

PubMed

Koch, Lauren Gerard; Kemi, Ole J; Qi, Nathan; Leng, Sean X; Bijma, Piter; Gilligan, Lori J; Wilkinson, John E; Wisløff, Helene; Høydal, Morten A; Rolim, Natale; Abadir, Peter M; van Grevenhof, Elizabeth M; Smith, Godfrey L; Burant, Charles F; Ellingsen, Oyvind; Britton, Steven L; Wisløff, Ulrik

2011-10-28

Low aerobic exercise capacity is a powerful predictor of premature morbidity and mortality for healthy adults as well as those with cardiovascular disease. For aged populations, poor performance on treadmill or extended walking tests indicates closer proximity to future health declines. Together, these findings suggest a fundamental connection between aerobic capacity and longevity. Through artificial selective breeding, we developed an animal model system to prospectively test the association between aerobic exercise capacity and survivability (aerobic hypothesis). Laboratory rats of widely diverse genetic backgrounds (N:NIH stock) were selectively bred for low or high intrinsic (inborn) treadmill running capacity. Cohorts of male and female rats from generations 14, 15, and 17 of selection were followed for survivability and assessed for age-related declines in cardiovascular fitness including maximal oxygen uptake (VO(2max)), myocardial function, endurance performance, and change in body mass. Median lifespan for low exercise capacity rats was 28% to 45% shorter than high capacity rats (hazard ratio, 0.06; P<0.001). VO(2max), measured across adulthood was a reliable predictor of lifespan (P<0.001). During progression from adult to old age, left ventricular myocardial and cardiomyocyte morphology, contractility, and intracellular Ca(2+) handling in both systole and diastole, as well as mean blood pressure, were more compromised in rats bred for low aerobic capacity. Physical activity levels, energy expenditure (Vo(2)), and lean body mass were all better sustained with age in rats bred for high aerobic capacity. These data obtained from a contrasting heterogeneous model system provide strong evidence that genetic segregation for aerobic exercise capacity can be linked with longevity and are useful for deeper mechanistic exploration of aging.

Aerobic and anaerobic methanotrophic communities in urban landscape wetland.

PubMed

Chen, Sili; Chen, Jianfei; Chang, Sha; Yi, Hao; Huang, Dawei; Xie, Shuguang; Guo, Qingwei

2018-01-01

Both aerobic methane-oxidizing bacteria (MOB) and nitrite-dependent anaerobic methane oxidation (n-damo) organisms can be important methane sinks in a wetland. However, the influences of the vegetation type on aerobic MOB and n-damo communities in wetland, especially in constructed wetland, remain poorly understood. The present study investigated the influences of the vegetation type on both aerobic MOB and n-damo organisms in a constructed urban landscape wetland. Sediments were collected from eight sites vegetated with different plant species. The abundance (1.19-3.27 × 10 7 pmoA gene copies per gram dry sediment), richness (Chao1 estimator = 16.3-81.5), diversity (Shannon index = 2.10-3.15), and structure of the sediment aerobic MOB community were found to vary considerably with sampling site. In contrast, n-damo community abundance (8.74 × 10 5 -4.80 × 10 6 NC10 16S rRNA gene copies per gram dry sediment) changed slightly with the sampling site. The richness (Chao1 estimator = 1-11), diversity (Shannon index = 0-0.78), and structure of the NC10 16S rRNA gene-based n-damo community illustrated slight site-related changes, while the spatial changes of the pmoA gene-based n-damo community richness (Chao1 estimator = 1-8), diversity (Shannon index = 0-0.99), and structure were considerable. The vegetation type could have a profound impact on the wetland aerobic MOB community and had a stronger influence on the pmoA-based n-damo community than on the NC10 16S-based one in urban wetland. Moreover, the aerobic MOB community had greater abundance and higher richness and diversity than the n-damo community. Methylocystis (type II MOB) predominated in urban wetland, while no known type I MOB species was detected. In addition, the ratio of total organic carbon to total nitrogen (C/N) might be a determinant of sediment n-damo community diversity and aerobic MOB richness.

Autoheated thermophilic aerobic digestion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deeny, K.; Hahn, H.; Leonhard, D.

1991-10-01

Autothermal thermophilic aerobic digestion (ATAD) is first and foremost a digestion process, the primary purpose of which is to decompose a portion of the waste organic solids generated from wastewater treatment. As a result of the high operating temperature, digestion is expected to occur within a short time period (6 days) and accomplish a high degree of pathogen reduction. ATAD systems are two-stage aerobic digestion processes that operate under thermophilic temperature conditions (40 to 80C) without supplemental heat. Like composting, the systems rely on the conservation of heat released during digestion itself to attain and sustain the desired operating temperature.more » Typical ATAD systems operate at 55C and may reach temperatures of 60 to 65C in the second-stage reactor. Perhaps because of the high operating temperature, this process has been referred to as Liquid Composting.' Major advantages associated with thermophilic operation include high biological reaction rates and a substantial degree of pathogen reduction.« less

Mutations reducing replication from R-loops suppress the defects of growth, chromosome segregation and DNA supercoiling in cells lacking topoisomerase I and RNase HI activity.

PubMed

Usongo, Valentine; Martel, Makisha; Balleydier, Aurélien; Drolet, Marc

2016-04-01

R-loop formation occurs when the nascent RNA hybridizes with the template DNA strand behind the RNA polymerase. R-loops affect a wide range of cellular processes and their use as origins of replication was the first function attributed to them. In Escherichia coli, R-loop formation is promoted by the ATP-dependent negative supercoiling activity of gyrase (gyrA and gyrB) and is inhibited by topoisomerase (topo) I (topA) relaxing transcription-induced negative supercoiling. RNase HI (rnhA) degrades the RNA moiety of R-loops. The depletion of RNase HI activity in topA null mutants was previously shown to lead to extensive DNA relaxation, due to DNA gyrase inhibition, and to severe growth and chromosome segregation defects that were partially corrected by overproducing topo III (topB). Here, DNA gyrase assays in crude cell extracts showed that the ATP-dependent activity (supercoiling) of gyrase but not its ATP-independent activity (relaxation) was inhibited in topA null cells lacking RNase HI. To characterize the cellular event(s) triggered by the absence of RNase HI, we performed a genetic screen for suppressors of the growth defect of topA rnhA null cells. Suppressors affecting genes in replication (holC2::aph and dnaT18::aph) nucleotide metabolism (dcd49::aph), RNA degradation (rne59::aph) and fimbriae synthesis (fimD22::aph) were found to reduce replication from R-loops and to restore supercoiling, thus pointing to a correlation between R-loop-dependent replication in topA rnhA mutants and the inhibition of gyrase activity and growth. Interestingly, the position of fimD on the E. coli chromosome corresponds to the site of one of the five main putative origins of replication from R-loops in rnhA null cells recently identified by next-generation sequencing, thus suggesting that the fimD22::aph mutation inactivated one of these origins. Furthermore, we show that topo III overproduction is unable to complement the growth defect of topA rnhA null mutants at low

The Longitudinal Impact of NFL PLAY 60 Programming on Youth Aerobic Capacity and BMI.

PubMed

Bai, Yang; Saint-Maurice, Pedro F; Welk, Gregory J; Russell, Daniel W; Allums-Featherston, Kelly; Candelaria, Norma

2017-03-01

The NFL PLAY 60 campaign has actively promoted physical activity and healthy eating in youth through programs such as the PLAY 60 Challenge and Fuel Up to PLAY 60. The purpose of the study was to evaluate the impact of NFL PLAY 60 programming on longitudinal trajectories of youth aerobic capacity and BMI. Data were from the NFL PLAY 60 FitnessGram Partnership Project, a large participatory research project designed to promote physical activity and healthy eating among Kindergarten through 12th grade children and adolescents. The programming was led by teachers in school settings across 32 NFL franchise markets. A range of 50,000-100,000 students from 497 schools completed FitnessGram assessments annually starting in 2011 and continuing through 2015. The analysis was conducted in 2015. Adoption of NFL PLAY 60 programming was encouraged but not required and the program implementation was evaluated each year. The adoption was evaluated through self-reported annual survey. School assessments of aerobic capacity and BMI were evaluated using FitnessGram standards to calculate the percentage of students meeting the Healthy Fitness Zone for each test. Growth curve modeling was used to estimate the longitudinal trajectories. About 19% of schools were classified as programming schools. Annual improvements in aerobic capacity were significantly greater in schools that participated in the programs for both girls (3.0%, p<0.01) and boys (2.9%, p<0.01) compared with non-programming schools. The annual improvements in BMI Healthy Fitness Zone achievement were also higher in girls (1.3%, p<0.05) and in boys (1.2%, p<0.05) from schools that participated in the programs versus non-participating schools. Schools that implemented the programs for the entire 4-year period tended to have better improvements in aerobic capacity than schools enrolled for only 2 or 3 years (p<0.05). The results of these longitudinal analyses support the utility of the NFL PLAY 60 physical activity

Investigation of defect modes in a defective photonic crystal with a semiconductor metamaterial defect

NASA Astrophysics Data System (ADS)

Wu, Meng-Ru; Wu, Chien-Jang; Chang, Shoou-Jinn

2014-11-01

In this work, we theoretically investigate the properties of defect modes in a defective photonic crystal containing a semiconductor metamaterial defect. We consider the structure, (LH)N/DP/(LH)N, where N and P are respectively the stack numbers, L is SiO2, H is InP, and defect layer D is a semiconductor metamaterial composed of Al-doped ZnO (AZO) and ZnO. It is found that, within the photonic band gap, the number of defect modes (transmission peaks) will decrease as the defect thickness increases, in sharp contrast to the case of using usual dielectric defect. The peak height and position can be changed by the variation in the thickness of defect layer. In the angle-dependent defect mode, its position is shown to be blue-shifted as the angle of incidence increases for both TE and TM waves. The analysis of defect mode provides useful information for the design of tunable transmission filter in semiconductor optoelectronics.

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.

Muscular and Aerobic Fitness, Working Memory, and Academic Achievement in Children.

PubMed

Kao, Shih-Chun; Westfall, Daniel R; Parks, Andrew C; Pontifex, Matthew B; Hillman, Charles H

2017-03-01

This study investigated the relationship between aerobic and muscular fitness with working memory and academic achievement in preadolescent children. Seventy-nine 9- to 11-yr-old children completed an aerobic fitness assessment using a graded exercise test; a muscular fitness assessment consisting of upper body, lower body, and core exercises; a serial n-back task to assess working memory; and an academic achievement test of mathematics and reading. Hierarchical regression analyses indicated that after controlling for demographic variables (age, sex, grade, IQ, socioeconomic status), aerobic fitness was associated with greater response accuracy and d' in the 2-back condition and increased mathematic performance in algebraic functions. Muscular fitness was associated with increased response accuracy and d', and longer reaction time in the 2-back condition. Further, the associations of muscular fitness with response accuracy and d' in the 2-back condition were independent of aerobic fitness. The current findings suggest the differential relationships between the aerobic and the muscular aspects of physical fitness with working memory and academic achievement. With the majority of research focusing on childhood health benefits of aerobic fitness, this study suggests the importance of muscular fitness to cognitive health during preadolescence.

Effects of Aerobic Exercise Based upon Heart Rate at Aerobic Threshold in Obese Elderly Subjects with Type 2 Diabetes

PubMed Central

Donini, Lorenzo Maria

2015-01-01

In obese diabetic subjects, a correct life style, including diet and physical activity, is part of a correct intervention protocol. Thus, the aim of this study was to evaluate the effects of aerobic training intervention, based on heart rate at aerobic gas exchange threshold (AerTge), on clinical and physiological parameters in obese elderly subjects with type 2 diabetes (OT2DM). Thirty OT2DM subjects were randomly assigned to an intervention (IG) or control group (CG). The IG performed a supervised aerobic exercise training based on heart rate at AerTge whereas CG maintained their usual lifestyle. Anthropometric measures, blood analysis, peak oxygen consumption (V˙O2peak), metabolic equivalent (METpeak), work rate (WRpeak), and WRAerTge were assessed at baseline and after intervention. After training, patients enrolled in the IG had significantly higher (P < 0.001) V˙O2peak, METpeak, WRpeak, and WRAerTge and significantly lower (P < 0.005) weight, BMI, %FM, and waist circumference than before intervention. Both IG and CG subjects had lower glycated haemoglobin levels after intervention period. No significant differences were found for all the other parameters between pre- and posttraining and between groups. Aerobic exercise prescription based upon HR at AerTge could be a valuable physical intervention tool to improve the fitness level and metabolic equilibrium in OT2DM patients. PMID:26089890

Grey water treatment in a series anaerobic--aerobic system for irrigation.

PubMed

Abu Ghunmi, Lina; Zeeman, Grietje; Fayyad, Manar; van Lier, Jules B

2010-01-01

This study aims at treatment of grey water for irrigation, focusing on a treatment technology that is robust, simple to operate and with minimum energy consumption. The result is an optimized system consisting of an anaerobic unit operated in upflow mode, with a 1 day operational cycle, a constant effluent flow rate and varying liquid volume. Subsequent aerobic step is equipped with mechanical aeration and the system is insulated for sustaining winter conditions. The COD removal achieved by the anaerobic and aerobic units in summer and winter are 45%, 39% and 53%, 64%, respectively. Sludge in the anaerobic and aerobic reactor has a concentration of 168 and 8 mg VSL(-1), respectively. Stability of sludge in the anaerobic and aerobic reactors is 80% and 93%, respectively, based on COD. Aerobic effluent quality, except for pathogens, agrees with the proposed irrigation water quality guidelines for reclaimed water in Jordan.

Melt-growth dynamics in CdTe crystals

DOE PAGES

Zhou, X. W.; Ward, D. K.; Wong, B. M.; ...

2012-06-01

We use a new, quantum-mechanics-based bond-order potential (BOP) to reveal melt growth dynamics and fine scale defect formation mechanisms in CdTe crystals. Previous molecular dynamics simulations of semiconductors have shown qualitatively incorrect behavior due to the lack of an interatomic potential capable of predicting both crystalline growth and property trends of many transitional structures encountered during the melt → crystal transformation. Here, we demonstrate successful molecular dynamics simulations of melt growth in CdTe using a BOP that significantly improves over other potentials on property trends of different phases. Our simulations result in a detailed understanding of defect formation during themore » melt growth process. Equally important, we show that the new BOP enables defect formation mechanisms to be studied at a scale level comparable to empirical molecular dynamics simulation methods with a fidelity level approaching quantum-mechanical methods.« less

Characterisation and modelling of defect formation in direct-chill cast AZ80 alloy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mackie, D.; Robson, J.D.; Withers, P.J.

2015-06-15

Wrought magnesium alloys for demanding structural applications require high quality defect free cast feedstock. The aim of this study was to first identify and characterise typical defects in direct chill cast magnesium–aluminium–zinc (AZ) alloy billet and then use modelling to understand the origins of these defects so they can be prevented. Defects were first located using ultrasonic inspection and were then characterised using X-ray computed tomography (XCT) and serial sectioning, establishing the presence of oxide films and intermetallic particles Al{sub 8}Mn{sub 5} in all defects. A model was developed to predict the flow patterns and growth kinetics of the intermetallicmore » phases during casting, which influence the formation of defects. Simulation of the growth of the intermetallic particles demonstrated that precipitation from the liquid occurs in the mould. The combination of the entrained oxide films and intermetallic particles recirculates in the liquid metal and continues to grow, until large enough to settle, which is predicted to occur at the centre of the mould where the flow is the slowest. Based on these predictions, strategies to reduce the susceptibility to defect formation are suggested. - Highlights: • Casting defects in magnesium direct chill casting have been imaged and characterised in 3-dimensions. • The occurrences of co-located clusters of particles and oxide films have been characterised and explained. • A coupled model has been developed to help interpret the observed trend for defects located towards the centre of billets.« less

Aerobic Degradation of N-Methyl-4-Nitroaniline (MNA) by Pseudomonas sp. Strain FK357 Isolated from Soil

PubMed Central

Khan, Fazlurrahman; Vyas, Bhawna; Pal, Deepika; Cameotra, Swaranjit Singh

2013-01-01

N-Methyl-4-nitroaniline (MNA) is used as an additive to lower the melting temperature of energetic materials in the synthesis of insensitive explosives. Although the biotransformation of MNA under anaerobic condition has been reported, its aerobic microbial degradation has not been documented yet. A soil microcosms study showed the efficient aerobic degradation of MNA by the inhabitant soil microorganisms. An aerobic bacterium, Pseudomonas sp. strain FK357, able to utilize MNA as the sole carbon, nitrogen, and energy source, was isolated from soil microcosms. HPLC and GC-MS analysis of the samples obtained from growth and resting cell studies showed the formation of 4-nitroaniline (4-NA), 4-aminophenol (4-AP), and 1, 2, 4-benzenetriol (BT) as major metabolic intermediates in the MNA degradation pathway. Enzymatic assay carried out on cell-free lysates of MNA grown cells confirmed N-demethylation reaction is the first step of MNA degradation with the formation of 4-NA and formaldehyde products. Flavin-dependent transformation of 4-NA to 4-AP in cell extracts demonstrated that the second step of MNA degradation is a monooxygenation. Furthermore, conversion of 4-AP to BT by MNA grown cells indicates the involvement of oxidative deamination (release of NH2 substituent) reaction in third step of MNA degradation. Subsequent degradation of BT occurs by the action of benzenetriol 1, 2-dioxygenase as reported for the degradation of 4-nitrophenol. This is the first report on aerobic degradation of MNA by a single bacterium along with elucidation of metabolic pathway. PMID:24116023

Aerobic degradation of N-methyl-4-nitroaniline (MNA) by Pseudomonas sp. strain FK357 isolated from soil.

PubMed

Khan, Fazlurrahman; Vyas, Bhawna; Pal, Deepika; Cameotra, Swaranjit Singh

2013-01-01

N-Methyl-4-nitroaniline (MNA) is used as an additive to lower the melting temperature of energetic materials in the synthesis of insensitive explosives. Although the biotransformation of MNA under anaerobic condition has been reported, its aerobic microbial degradation has not been documented yet. A soil microcosms study showed the efficient aerobic degradation of MNA by the inhabitant soil microorganisms. An aerobic bacterium, Pseudomonas sp. strain FK357, able to utilize MNA as the sole carbon, nitrogen, and energy source, was isolated from soil microcosms. HPLC and GC-MS analysis of the samples obtained from growth and resting cell studies showed the formation of 4-nitroaniline (4-NA), 4-aminophenol (4-AP), and 1, 2, 4-benzenetriol (BT) as major metabolic intermediates in the MNA degradation pathway. Enzymatic assay carried out on cell-free lysates of MNA grown cells confirmed N-demethylation reaction is the first step of MNA degradation with the formation of 4-NA and formaldehyde products. Flavin-dependent transformation of 4-NA to 4-AP in cell extracts demonstrated that the second step of MNA degradation is a monooxygenation. Furthermore, conversion of 4-AP to BT by MNA grown cells indicates the involvement of oxidative deamination (release of NH2 substituent) reaction in third step of MNA degradation. Subsequent degradation of BT occurs by the action of benzenetriol 1, 2-dioxygenase as reported for the degradation of 4-nitrophenol. This is the first report on aerobic degradation of MNA by a single bacterium along with elucidation of metabolic pathway.

Vacuolar invertase gene silencing in potato decreasing the frequency of sugar-end defects

USDA-ARS?s Scientific Manuscript database

Sugar-end defect is a tuber quality disorder and persistent problem for the French fry processing industry that causes unacceptable darkening of one end of French fries. This defect appears when environmental stress during tuber growth increases post-harvest vacuolar acid invertase activity at one e...

Reduced anaerobic and aerobic performance in children with primary ciliary dyskinesia.

PubMed

Simsek, Senem; Inal-Ince, Deniz; Cakmak, Aslihan; Emiralioglu, Nagehan; Calik-Kutukcu, Ebru; Saglam, Melda; Vardar-Yagli, Naciye; Ozcelik, Hayriye Ugur; Sonbahar-Ulu, Hazal; Bozdemir-Ozel, Cemile; Kiper, Nural; Arikan, Hulya

2018-05-01

Primary ciliary dyskinesia (PCD) restricts lifestyle and increases morbidity. The aim of the study was to investigate anaerobic and aerobic performance in children with PCD and their healthy counterparts. Thirty-one children with PCD and 29 age- and sex-matched healthy subjects were studied. Pulmonary function, hand grip strength (HGS), quadriceps strength (QMS), physical activity, anaerobic capacity (muscle power sprint test), and aerobic performance (modified shuttle walk test (MSWT)) were determined. Pulmonary function, HGS, QMS, mean anaerobic power (MAP), and MSWT distance in PCD were significantly lower than those of healthy subjects (p < 0.05). In PCD, the MAP was significantly correlated with age, FEV 1 , and the mean kcal for 3 days (p < 0.05), and age was its independent predictor (p < 0.05). The MSWT distance was significantly related to gender and weight (p < 0.05), and gender was selected as its independent predictor (p < 0.05). In healthy controls, the MAP was significantly associated with age, gender, FVC, FEV 1 , HGS, QMS, and the mean kcal for three days (p < 0.05). The MSWT distance was significantly related to weight and body mass index in healthy group (p < 0.05). Anaerobic and aerobic performance is impaired in PCD from the early stages. Age determines anaerobic performance. Gender is the determinant of aerobic performance. Whether skeletal muscle characteristics and sex-related changes in body composition affect anaerobic and aerobic capacity in PCD children warrants further study. What is Known: • Exercise performance is determined by anaerobic and aerobic power. • Few studies have shown that PCD patients have lower aerobic performance which is associated with impaired lung function. What is New: • The present research indicated that both anaerobic and aerobic exercise capacity determined using field testing is impaired in PCD from the early stages. • Anaerobic capacity was found to be independently

Dental enamel defects predict adolescent health indicators: A cohort study among the Tsimane' of Bolivia.

PubMed

Masterson, Erin E; Fitzpatrick, Annette L; Enquobahrie, Daniel A; Mancl, Lloyd A; Eisenberg, Dan T A; Conde, Esther; Hujoel, Philippe P

2018-05-01

Bioarchaeological findings have linked defective enamel formation in preadulthood with adult mortality. We investigated how defective enamel formation in infancy and childhood is associated with risk factors for adult morbidity and mortality in adolescents. This cohort study of 349 Amerindian adolescents (10-17 years of age) related extent of enamel defects on the central maxillary incisors (none, less than 1/3, 1/3 to 2/3, more than 2/3) to adolescent anthropometrics (height, weight) and biomarkers (hemoglobin, glycated hemoglobin, white blood cell count, and blood pressure). Risk differences and 95% confidence intervals were estimated using multiple linear regression. Enamel defects and stunted growth were compared in their ability to predict adolescent health indicators using log-binomial regression and receiver operating characteristics (ROCs). Greater extent of defective enamel formation on the tooth surface was associated with shorter height (-1.35 cm, 95% CI: -2.17, -0.53), lower weight (-0.98 kg, 95% CI: -1.70, -0.26), lower hemoglobin (-0.36 g/dL, 95% CI: -0.59, -0.13), lower glycated hemoglobin (-0.04 %A 1c , 95% CI: -0.08, -0.00008), and higher white blood cell count (0.74 10 9 /L, 95% CI: 0.35, 1.14) in adolescence. Extent of enamel defects and stunted growth independently performed similarly as risk factors for adverse adolescent outcomes, including anemia, prediabetes/type II diabetes, elevated WBC count, prehypertension/hypertension, and metabolic health. Defective enamel formation in infancy and childhood predicted adolescent health outcomes and may be primarily associated with infection. Extent of enamel defects and stunted growth may be equally predictive of adverse adolescent health outcomes. © 2018 Wiley Periodicals, Inc.

Aerobic vs. resistance exercise in non-alcoholic fatty liver disease: A systematic review.

PubMed

Hashida, Ryuki; Kawaguchi, Takumi; Bekki, Masafumi; Omoto, Masayuki; Matsuse, Hiroo; Nago, Takeshi; Takano, Yoshio; Ueno, Takato; Koga, Hironori; George, Jacob; Shiba, Naoto; Torimura, Takuji

2017-01-01

Exercise is a first-line therapy for patients with non-alcoholic fatty liver disease (NAFLD). We sought to: 1) summarize effective aerobic and resistance exercise protocols for NAFLD; and 2) compare the effects and energy consumption of aerobic and resistance exercises. A literature search was performed using PubMed, Web of Science, and Scopas to January 28, 2016. From a total of 95 articles, 23 studies including 24 aerobic and 7 resistance exercise protocols were selected for the summary of exercise protocols. Twelve articles including 13 aerobic and 4 resistance exercise protocols were selected for the comparative analysis. For aerobic exercise, the median effective protocol was 4.8 metabolic equivalents (METs) for 40min/session, 3times/week for 12weeks. For resistance exercise, the median effective protocol was 3.5 METs for 45min/session, 3times/week for 12weeks. Aerobic and resistance exercise improved hepatic steatosis. No significant difference was seen in the duration, frequency, or period of exercise between the two exercise groups; however, %VO 2 max and energy consumption were significantly lower in the resistance than in the aerobic group (50% [45-98] vs. 28% [28-28], p=0.0034; 11,064 [6394-21,087] vs. 6470 [4104-12,310] kcal/total period, p=0.0475). Resistance exercise improves NAFLD with less energy consumption. Thus, resistance exercise may be more feasible than aerobic exercise for NAFLD patients with poor cardiorespiratory fitness or for those who cannot tolerate or participate in aerobic exercise. These data may indicate a possible link between resistance exercise and lipid metabolism in the liver. Both aerobic and resistance exercise reduce hepatic steatosis in non-alcoholic fatty liver disease (NAFLD) with similar frequency, duration, and period of exercise (40-45min/session 3times/week for 12weeks); however, the two forms of exercise have different characteristics. Intensity and energy consumption were significantly lower for resistance than for

Reduction of structural defects in thick 4H-SiC epitaxial layers grown on 4° off-axis substrates

NASA Astrophysics Data System (ADS)

Yazdanfar, M.; Ivanov, I. G.; Pedersen, H.; Kordina, O.; Janzén, E.

2013-06-01

By carefully controlling the surface chemistry of the chemical vapor deposition process for silicon carbide (SiC), 100 μm thick epitaxial layers with excellent morphology were grown on 4° off-axis SiC substrates at growth rates exceeding 100 μm/h. In order to reduce the formation of step bunching and structural defects, mainly triangular defects, the effect of varying parameters such as growth temperature, C/Si ratio, Cl/Si ratio, Si/H2 ratio, and in situ pre-growth surface etching time are studied. It was found that an in-situ pre growth etch at growth temperature and pressure using 0.6% HCl in hydrogen for 12 min reduced the structural defects by etching preferentially on surface damages of the substrate surface. By then applying a slightly lower growth temperature of 1575 °C, a C/Si ratio of 0.8, and a Cl/Si ratio of 5, 100 μm thick, step-bunch free epitaxial layer with a minimum triangular defect density and excellent morphology could be grown, thus enabling SiC power device structures to be grown on 4° off axis SiC substrates.

[Aerobic vaginitis--diagnostic problems and treatment].

PubMed

Romanik, Małgorzata; Wojciechowska-Wieja, Anna; Martirosian, Gayane

2007-06-01

The diagnostic criteria and treatment of aerobic vaginitis--AV--have been summarized in this review. An expansion of mixed aerobic microflora, especially Group B Streptococcus--GBS, Escherichia coli--E. coli, Enterococcus spp., and the development of inflammation of the vaginal mucous membrane due to a decreasing amount of Lactobacillus spp., have been observed in women with AV. Disruptions of the vaginal ecosystem during AV cause an increase in pH to >6, a decrease in lactates concentration and an increase in proinflammatory cytokines concentration in vaginal discharge. An optimal treatment scheme for AV, which includes antibacterial agents and simultaneously normalizes the vaginal ecosystem, has not been established until today.

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…

Kinetic Defects Induced by Melittin in Model Lipid Membranes: A Solution Atomic Force Microscopy Study.

PubMed

Pan, Jianjun; Khadka, Nawal K

2016-05-26

Quantitative characterization of membrane defects (pores) is important for elucidating the molecular basis of many membrane-active peptides. We study kinetic defects induced by melittin in vesicular and planar lipid bilayers. Fluorescence spectroscopy measurements indicate that melittin induces time-dependent calcein leakage. Solution atomic force microscopy (AFM) is used to visualize melittin-induced membrane defects. After initial equilibration, the most probable defect radius is ∼3.8 nm in 1,2-dilauroyl-sn-glycero-3-phosphocholine (DLPC) bilayers. Unexpectedly, defects become larger with longer incubation, accompanied by substantial shape transformation. The initial defect radius is ∼4.7 nm in 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) bilayers. Addition of 30 mol % cholesterol to DOPC bilayers suppresses defect kinetics, although the inhibitory impact is negated by longer incubation. Overall, the kinetic rate of defect development follows DLPC > DOPC > DOPC/cholesterol. Kinetic defects are also observed when anionic lipids are present. Based on the observation that defects can occupy as large as 40% of the bilayer surface, we propose a kinetic defect growth model. We also study the effect of melittin on the phase behavior of DOPC/egg-sphingomyelin/cholesterol bilayers. We find that melittin initially suppresses or eliminates liquid-ordered (Lo) domains; Lo domains gradually emerge and become the dominant species with longer incubation; and defects in phase-coexisting bilayers have a most probable radius of ∼5 nm and are exclusively localized in the liquid-disordered (Ld) phase. Our experimental data highlight that melittin-induced membrane defects are not static; conversely, spontaneous defect growth is intrinsically associated with membrane permeabilization exerted by melittin.

Within-Winter Flexibility in Muscle Masses, Myostatin, and Cellular Aerobic Metabolic Intensity in Passerine Birds.

PubMed

Swanson, David L; King, Marisa O; Culver, William; Zhang, Yufeng

Metabolic rates of passerine birds are flexible traits that vary both seasonally and among and within winters. Seasonal variation in summit metabolic rates (M sum = maximum thermoregulatory metabolism) in birds is consistently correlated with changes in pectoralis muscle and heart masses and sometimes with variation in cellular aerobic metabolic intensity, so these traits might also be associated with shorter-term, within-winter variation in metabolic rates. To determine whether these mechanisms are associated with within-winter variation in M sum , we examined the effects of short-term (ST; 0-7 d), medium-term (MT; 14-30 d), and long-term (LT; 30-yr means) temperature variables on pectoralis muscle and heart masses, pectoralis expression of the muscle-growth inhibitor myostatin and its metalloproteinase activators TLL-1 and TLL-2, and pectoralis and heart citrate synthase (CS; an indicator of cellular aerobic metabolic intensity) activities for two temperate-zone resident passerines, house sparrows (Passer domesticus) and dark-eyed juncos (Junco hyemalis). For both species, pectoralis mass residuals were positively correlated with ST temperature variables, suggesting that cold temperatures resulted in increased turnover of pectoralis muscle, but heart mass showed little within-winter variation for either species. Pectoralis mRNA and protein expression of myostatin and the TLLs were only weakly correlated with ST and MT temperature variables, which is largely consistent with trends in muscle masses for both species. Pectoralis and heart CS activities showed weak and variable trends with ST temperature variables in both species, suggesting only minor effects of temperature variation on cellular aerobic metabolic intensity. Thus, neither muscle or heart masses, regulation by the myostatin system, nor cellular aerobic metabolic intensity varied consistently with winter temperature, suggesting that other factors regulate within-winter metabolic variation in these birds.

Combined Aerobic/Strength Training and Energy Expenditure in Older Women

PubMed Central

Hunter, Gary R.; Bickel, C. Scott; Fisher, Gordon; Neumeier, William; McCarthy, John

2013-01-01

Purpose To examine the effects of three different frequencies of combined resistance and aerobic training on total energy expenditure (TEE) and activity related energy expenditure (AEE) in a group of older adults. Methods Seventy-two women, 60 – 74 years old, were randomly assigned to one of three groups: 1 day/week of aerobic and 1 day/week of resistance (1+1); 2 days/week of aerobic and 2 days/week resistance (2+2); or 3 days/week aerobic and 3 days/week resistance (3+3). Body composition (DXA), feeling of fatigue, depression, and vigor (questionnaire), strength (1RM), serum cytokines (ELISA), maximal oxygen uptake (progressive treadmill test), resting energy expenditure, and TEE were measured before and after 16 weeks of training. Aerobic training consisted of 40 minutes of aerobic exercise at 80% maximum heart rate and resistance training consisted of 2 sets of 10 repetitions for 10 different exercises at 80% of one repetition maximum. Results All groups increased fat free mass, strength and aerobic fitness and decreased fat mass. No changes were observed in cytokines or perceptions of fatigue/depression. No time by group interaction was found for any fitness/body composition variable. TEE and AEE increased with the 2+2 group but not with the other two groups. Non-exercise training AEE (NEAT) increased significantly in the 2+2 group (+200 kcal/day), group 1×1 showed a trend for an increase (+68 kcal/day) and group 3+3 decreased significantly (−150 kcal/day). Conclusion Results indicate that 3+3 training may inhibit NEAT by being too time consuming and does not induce superior training adaptations to 1+1 and 2+2 training. Key words: physical activity, older adults, total energy expenditure, maximum oxygen uptake. PMID:23774582

Start-up, steady state performance and kinetic evaluation of a thermophilic integrated anaerobic-aerobic bioreactor (IAAB).

PubMed

Chan, Yi Jing; Chong, Mei Fong; Law, Chung Lim

2012-12-01

Thermophilic treatment of palm oil mill effluent (POME) was studied in a novel integrated anaerobic-aerobic bioreactor (IAAB). The IAAB was subjected to a program of steady-state operation over a range of organic loading rate (OLR)s, up to 30 g COD/L day in order to evaluate its treatment capacity. The thermophilic IAAB achieved high chemical oxygen demand (COD), biochemical oxygen demand (BOD) and total suspended solids (TSS) removal efficiencies of more than 99% for OLR up to 18.5 g COD/L day. High methane yield of 0.32 LCH(4) (STP)/g COD(removed) with compliance of the final treated effluent to the discharge limit were achieved. This is higher than that of the mesophilic system due to the higher maximum specific growth rate (μ(max)) of the thermophilic microorganisms. Besides, coupling the model of Grau second order model (anaerobic system) with the model of Monod (aerobic system) will completely define the IAAB system. Copyright © 2012 Elsevier Ltd. All rights reserved.

Influence of glyphosate in planktonic and biofilm growth of Pseudomonas aeruginosa

PubMed Central

Lima, Ilana Schneider; Baumeier, Nicole Carmo; Rosa, Rosimeire Takaki; Campelo, Patrícia Maria Stuelp; Rosa, Edvaldo Antonio Ribeiro

2014-01-01

This study evaluated the impact of different concentrations of glyphosate (Rondup®) on planktonic and biofilm growth of P. aeruginosa. Aerobic and anaerobic cultures of P. aeruginosa ATCC®15442 inoculated in MHB + glyphosate (0.845 ppm, 1.690 ppm, 8.45 ppm, 16.90 ppm, 84.50 ppm, 169 ppm, 845 ppm, and 1690 ppm) and cultured in normoxia and anoxia, following their OD560nm every hour for 24 h. Biofilms of adapted cells were formed in the presence of glyphosate (0.845 to 1690 ppm) in normoxia and anoxia for 36 h. Glyphosate at concentrations higher than 84.5 ppm reduces the cell density of planktonic aerobic cultures (p < 0.05). However, these same concentrations favor the planktonic anaerobic growth (p < 0.05). On the other hand, the herbicide favors a slight growth of biofilms in a concentration-dependent manner up to 84.5 ppm (p > 0.05), and more pronounced over 169 ppm. Anaerobic biofilms have their growth more readily favored (p < 0.05), regardless of concentration. In a concentration-dependent manner, glyphosate interferes with the growth ability of P. aeruginosa ATCC®15442. PMID:25477933

Aerobic performance and body composition changes during military service

PubMed Central

Mikkola, Ilona; Keinänen-Kiukaanniemi, Sirkka; Jokelainen, Jari; Peitso, Ari; Härkönen, Pirjo; Timonen, Markku; Ikäheimo, Tiina

2012-01-01

Objective To examine the association between aerobic performance and body composition changes by body mass index (BMI). Design 6–12 months’ follow-up during military service. Setting Conscripts entering military service in 2005 in Sodankylä Jaeger Brigade (Finland). Subjects 945 men (19 years, SD 1 years). Main outcome measures Height, weight, waist circumference, BMI, and aerobic performance (Cooper test) were recorded. Body composition was measured by bioelectrical impedance analysis (BIA). The measured parameters were fat mass (FM), fat free mass (FFM), and visceral fat area (VFA). All the measurements were performed at the beginning and end of service. Results On average, the military training period improved the running distance by 6.8% (169 m, p < 0.001) and the improvements were more pronounced in overweight (223.9 m/9.5%, p < 0.001) and obese (273.3 m/13.6 %, p < 0.001) conscripts. A strong inverse correlation between aerobic performance and body composition changes was observed, especially for weight (r = –0.305, p < 0.001) and VFA (r = –0.465, p < 0.001). A significant association between aerobic performance and changes in weight (p < 0.001), waist circumference (p < 0.001), FM (p < 0.001), and VFA (p < 0.001) by BMI was detected. The associated decrease in weight, waist circumference, FM, and VFA with improved aerobic performance was more substantial between overweight and obese compared with normal-weight subjects. Conclusions Favourable changes in body composition are associated with improved aerobic performance during a physical training period such as military service. These findings are pronounced among overweight and obese men and can be applied at the population level in reducing obesity and co-morbidities. PMID:22643154

Influence of aerobic fitness on vasoreactivity in young men.

PubMed

Bell, Preston L; Kelley, Edward T; McCoy, Stephanie M; Credeur, Daniel P

2017-10-01

Previous work has demonstrated a direct relationship between aerobic fitness and vasodilatory function (i.e., flow-mediated dilation; FMD); however, the relation between aerobic fitness and vasoconstrictor responsiveness (i.e., low flow-mediated constriction; L-FMC), and the overall vasoactive range (FMD + L-FMC) is unclear. To test the hypothesis that L-FMC and the overall vasoactive range (FMD + L-FMC) will be related to aerobic fitness in young, healthy men. Twenty men (age: 23 ± 5 years) were recruited, and divided evenly into a higher (HF) vs. lower (LF) aerobic fitness group, quantified via YMCA cycle ergometry (VO 2 peak extrapolation), and a 3-min step test (1-min heart rate recovery). Duplex Doppler-ultrasound was used to assess brachial artery FMD and L-FMC. Estimated VO 2 peak (HF = 55 ± 10 vs. LF = 38 ± 5 mL/kg/min) and heart rate recovery (HF = 36 ± 10 vs. LF = 25 ± 8 beats) were greater in the HF group (P < 0.05). FMD and the vasoactive range were similar between groups; however, L-FMC was significantly greater in HF (HF = -2.5 ± 1.6 vs. LF = -0.7 ± 1.8%, P < 0.05; d = 1.18). A correlational analysis revealed an inverse relationship between L-FMC and both HR recovery (r = -0.665, P < 0.01) and estimated VO 2 peak (r = -0.5, P < 0.05). This work supports an association between L-FMC and aerobic fitness in young, healthy men. Longitudinal or interventional studies are warranted to support causality, and to distinguish whether L-FMC is more sensitive to changes in aerobic fitness than FMD.

Microbial acceleration of aerobic pyrite oxidation at circumneutral pH.

PubMed

Percak-Dennett, E; He, S; Converse, B; Konishi, H; Xu, H; Corcoran, A; Noguera, D; Chan, C; Bhattacharyya, A; Borch, T; Boyd, E; Roden, E E

2017-09-01

Pyrite (FeS 2 ) is the most abundant sulfide mineral on Earth and represents a significant reservoir of reduced iron and sulfur both today and in the geologic past. In modern environments, oxidative transformations of pyrite and other metal sulfides play a key role in terrestrial element partitioning with broad impacts to contaminant mobility and the formation of acid mine drainage systems. Although the role of aerobic micro-organisms in pyrite oxidation under acidic-pH conditions is well known, to date there is very little known about the capacity for aerobic micro-organisms to oxidize pyrite at circumneutral pH. Here, we describe two enrichment cultures, obtained from pyrite-bearing subsurface sediments, that were capable of sustained cell growth linked to pyrite oxidation and sulfate generation at neutral pH. The cultures were dominated by two Rhizobiales species (Bradyrhizobium sp. and Mesorhizobium sp.) and a Ralstonia species. Shotgun metagenomic sequencing and genome reconstruction indicated the presence of Fe and S oxidation pathways in these organisms, and the presence of a complete Calvin-Benson-Bassham CO 2 fixation system in the Bradyrhizobium sp. Oxidation of pyrite resulted in thin (30-50 nm) coatings of amorphous Fe(III) oxide on the pyrite surface, with no other secondary Fe or S phases detected by electron microscopy or X-ray absorption spectroscopy. Rates of microbial pyrite oxidation were approximately one order of magnitude higher than abiotic rates. These results demonstrate the ability of aerobic microbial activity to accelerate pyrite oxidation and expand the potential contribution of micro-organisms to continental sulfide mineral weathering around the time of the Great Oxidation Event to include neutral-pH environments. In addition, our findings have direct implications for the geochemistry of modern sedimentary environments, including stimulation of the early stages of acid mine drainage formation and mobilization of pyrite

Oxygen-induced defects at the lead halide perovskite/graphene oxide interfaces

DOE PAGES

Acik, Muge; Park, In Kee; Koritala, Rachel E.; ...

2017-12-21

Here, graphene oxide or its reduced derivative (GO/RGO) replace metal oxides in perovskite photovoltaics to achieve energy band alignment for minimization of the energy barriers at the film interfaces allowing efficient charge transport, and eliminate stability issues. However, the power conversion efficiencies fall in a wide range (~0.6–18%). Therefore, the perovskite growth and nucleation on GO/RGO require fundamental understanding to improve device function for controlled fabrication, which remain a major challenge. We analyze the surface morphology and crystallization of the lead halide perovskites (MAPbX 3) at 20–300 °C on GO using X-ray diffraction and photoelectron spectroscopy. To determine defect mechanismsmore » and their composition, we perform in situ transmission infrared and micro Raman spectroscopy, and the cross-sectional scanning microscopy that captures interfacial imperfections with the oxygen defects. We demonstrate the oxygen-induced defects at the MAPbX 3/GO interfaces that initiate at room temperature, and occur through the nucleophilic substitution reactions. Unexpectedly, structural defects nucleate in GO forming chemically reduced GO, and modify the surface morphology that yield a poor perovskite growth. Our theoretical studies also reveal that energetically favorable, exothermic reactions between the halides of the perovskite precursors and the oxygen groups of GO generate acidic reaction by-products ( i.e. HX), that confirm the formation of oxygen-induced defects.« less

Oxygen-induced defects at the lead halide perovskite/graphene oxide interfaces

DOE Office of Scientific and Technical Information (OSTI.GOV)

Acik, Muge; Park, In Kee; Koritala, Rachel E.

Here, graphene oxide or its reduced derivative (GO/RGO) replace metal oxides in perovskite photovoltaics to achieve energy band alignment for minimization of the energy barriers at the film interfaces allowing efficient charge transport, and eliminate stability issues. However, the power conversion efficiencies fall in a wide range (~0.6–18%). Therefore, the perovskite growth and nucleation on GO/RGO require fundamental understanding to improve device function for controlled fabrication, which remain a major challenge. We analyze the surface morphology and crystallization of the lead halide perovskites (MAPbX 3) at 20–300 °C on GO using X-ray diffraction and photoelectron spectroscopy. To determine defect mechanismsmore » and their composition, we perform in situ transmission infrared and micro Raman spectroscopy, and the cross-sectional scanning microscopy that captures interfacial imperfections with the oxygen defects. We demonstrate the oxygen-induced defects at the MAPbX 3/GO interfaces that initiate at room temperature, and occur through the nucleophilic substitution reactions. Unexpectedly, structural defects nucleate in GO forming chemically reduced GO, and modify the surface morphology that yield a poor perovskite growth. Our theoretical studies also reveal that energetically favorable, exothermic reactions between the halides of the perovskite precursors and the oxygen groups of GO generate acidic reaction by-products ( i.e. HX), that confirm the formation of oxygen-induced defects.« less

The medically important aerobic actinomycetes: epidemiology and microbiology.

PubMed Central

McNeil, M M; Brown, J M

1994-01-01

The aerobic actinomycetes are soil-inhabiting microorganisms that occur worldwide. In 1888, Nocard first recognized the pathogenic potential of this group of microorganisms. Since then, several aerobic actinomycetes have been a major source of interest for the commercial drug industry and have proved to be extremely useful microorganisms for producing novel antimicrobial agents. They have also been well known as potential veterinary pathogens affecting many different animal species. The medically important aerobic actinomycetes may cause significant morbidity and mortality, in particular in highly susceptible severely immunocompromised patients, including transplant recipients and patients infected with human immunodeficiency virus. However, the diagnosis of these infections may be difficult, and effective antimicrobial therapy may be complicated by antimicrobial resistance. The taxonomy of these microorganisms has been problematic. In recent revisions of their classification, new pathogenic species have been recognized. The development of additional and more reliable diagnostic tests and of a standardized method for antimicrobial susceptibility testing and the application of molecular techniques for the diagnosis and subtyping of these microorganisms are needed to better diagnose and treat infected patients and to identify effective control measures for these unusual pathogens. We review the epidemiology and microbiology of the major medically important aerobic actinomycetes. Images PMID:7923055

New Growth Mode through Decorated Twin Boundaries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bleikamp, Sebastian; Thoma, Arne; Polop, Celia

2006-03-24

Scanning tunneling microscopy and low energy electron diffraction were used to investigate the growth of partly twinned Ir thin films on Ir(111). A transition from the expected layer-by-layer to a defect dominated growth mode with a fixed lateral length scale and increasing roughness is observed. During growth, the majority of the film is stably transformed to twinned stacking. This transition is initiated by the energetic avoidance of the formation of intrinsic stacking faults compared to two independent twin faults. The atomistic details of the defect kinetics are outlined.

New growth mode through decorated twin boundaries.

PubMed

Bleikamp, Sebastian; Thoma, Arne; Polop, Celia; Pirug, Gerhard; Linke, Udo; Michely, Thomas

2006-03-24

Scanning tunneling microscopy and low energy electron diffraction were used to investigate the growth of partly twinned Ir thin films on Ir(111). A transition from the expected layer-by-layer to a defect dominated growth mode with a fixed lateral length scale and increasing roughness is observed. During growth, the majority of the film is stably transformed to twinned stacking. This transition is initiated by the energetic avoidance of the formation of intrinsic stacking faults compared to two independent twin faults. The atomistic details of the defect kinetics are outlined.

Role of seagrass photosynthesis in root aerobic processes.

PubMed

Smith, R D; Dennison, W C; Alberte, R S

1984-04-01

The role of shoot photosynthesis as a means of supporting aerobic respiration in the roots of the seagrass Zostera marina was examined. O(2) was transported rapidly (10-15 minutes) from the shoots to the root-rhizome tissues upon shoot illumination. The highest rates of transport were in shoots possessing the greatest biomass and leaf area. The rates of O(2) transport do not support a simple gas phase diffusion mechanism. O(2) transport to the root-rhizome system supported aerobic root respiration and in many cases exceeded respiratory requirements leading to O(2) release from the subterranean tissue. Release of O(2) can support aerobic processes in reducing sediments typical of Z. marina habitats. Since the root-rhizome respiration is supported primarily under shoot photosynthetic conditions, then the daily period of photosynthesis determines the diurnal period of root aerobiosis.

Performance of sequential anaerobic/aerobic digestion applied to municipal sewage sludge.

PubMed

Tomei, M Concetta; Rita, Sara; Mininni, Giuseppe

2011-07-01

A promising alternative to conventional single phase processing, the use of sequential anaerobic-aerobic digestion, was extensively investigated on municipal sewage sludge from a full scale wastewater treatment plant. The objective of the work was to evaluate sequential digestion performance by testing the characteristics of the digested sludge in terms of volatile solids (VS), Chemical Oxygen Demand (COD) and nitrogen reduction, biogas production, dewaterability and the content of proteins and polysaccharides. VS removal efficiencies of 32% in the anaerobic phase and 17% in the aerobic one were obtained, and similar COD removal efficiencies (29% anaerobic and 21% aerobic) were also observed. The aerobic stage was also efficient in nitrogen removal providing a decrease of the nitrogen content in the supernatant attributable to nitrification and simultaneous denitrification. Moreover, in the aerobic phase an additional marked removal of proteins and polysaccharides produced in the anaerobic phase was achieved. The sludge dewaterability was evaluated by determining the Optimal Polymer Dose (OPD) and the Capillary Suction Time (CST) and a significant positive effect due to the aerobic stage was observed. Biogas production was close to the upper limit of the range of values reported in the literature in spite of the low anaerobic sludge retention time of 15 days. From a preliminary analysis it was found that the energy demand of the aerobic phase was significantly lower than the recovered energy in the anaerobic phase and the associated additional cost was negligible in comparison to the saving derived from the reduced amount of sludge to be disposed. Copyright © 2011 Elsevier Ltd. All rights reserved.

Bending nanowire growth in solution by mechanical disturbance.

PubMed

Wang, Chao; Wei, Yujie; Jiang, Hongyuan; Sun, Shouheng

2010-06-09

The effect of mechanical disturbance on one-dimensional nanocrystal growth in solution phase is investigated by controlled growth of Au nanowires with and without stirring. While a static growth leads to straight, single-crystal Au nanowires, the mechanic disturbance by stirring tends to bend the nanowire growth, yielding nanowire kinks abundant in various types of crystal defects including dislocations, twin boundaries, and grain boundaries. Mechanical modeling and analysis is introduced to elucidate the nanowire growth mechanisms in these two conditions. The provided fundamental understanding of crystal defect formation at nanoscale could be applied to guide the development of advanced nanomaterials with shape control and unique mechanical properties.

Eisenmenger ventricular septal defect in a Humboldt penguin (Spheniscus humboldti).

PubMed

Laughlin, D S; Ialeggio, D M; Trupkiewicz, J G; Sleeper, M M

2016-09-01

The Eisenmenger ventricular septal defect is an uncommon type of ventricular septal defect characterised in humans by a traditionally perimembranous ventricular septal defect, anterior deviation (cranioventral deviation in small animal patients) of the muscular outlet septum causing malalignment relative to the remainder of the muscular septum, and overriding of the aortic valve. This anomaly is reported infrequently in human patients and was identified in a 45-day-old Humboldt Penguin, Spheniscus humboldti, with signs of poor growth and a cardiac murmur. This case report describes the findings in this penguin and summarises the anatomy and classification of this cardiac anomaly. To the authors' knowledge this is the first report of an Eisenmenger ventricular septal defect in a veterinary patient. Copyright © 2016 Elsevier B.V. All rights reserved.

Aerobic Activity Preferences among Older Canadians: A Time Use Perspective.

PubMed

Spinney, Jamie E L

2013-12-01

Numerous health benefits are associated with a physically active population. This study sought to discover the aerobic activity preferences among older Canadians. Four cycles of nationally representative time use data were fused with energy expenditure information to determine both participation rates and time spent in the 10 most frequently reported aerobic activities. Aerobic activity preferences are dominated by domestic chores (15% to 30% participation for about two hours per day), recreational walking (15% to 30% participation for about one hour per day), and active transportation (generally less than 5% participation for less than 30 minutes per day). Although there have been several changes in older Canadians’ revealed preferences for aerobic activities over the past three decades, the prevalence of domestic chores points towards the importance of policies that support older Canadians remaining in their homes, whereas the popularity of walking suggests that “walkability” needs to be considered in neighbourhood design.

High Fat Diet Induced Developmental Defects in the Mouse: Oocyte Meiotic Aneuploidy and Fetal Growth Retardation/Brain Defects

PubMed Central

Purcell, Scott H.; Chi, Maggie; Jimenez, Patricia T.; Grindler, Natalia; Schedl, Tim; Moley, Kelle H.

2012-01-01

Background Maternal obesity is associated with poor outcomes across the reproductive spectrum including infertility, increased time to pregnancy, early pregnancy loss, fetal loss, congenital abnormalities and neonatal conditions. Furthermore, the proportion of reproductive-aged woman that are obese in the population is increasing sharply. From current studies it is not clear if the origin of the reproductive complications is attributable to problems that arise in the oocyte or the uterine environment. Methodology/Principal Findings We examined the developmental basis of the reproductive phenotypes in obese animals by employing a high fat diet mouse model of obesity. We analyzed very early embryonic and fetal phenotypes, which can be parsed into three abnormal developmental processes that occur in obese mothers. The first is oocyte meiotic aneuploidy that then leads to early embryonic loss. The second is an abnormal process distinct from meiotic aneuploidy that also leads to early embryonic loss. The third is fetal growth retardation and brain developmental abnormalities, which based on embryo transfer experiments are not due to the obese uterine environment but instead must be from a defect that arises prior to the blastocyst stage. Conclusions/Significance Our results suggest that reproductive complications in obese females are, at least in part, from oocyte maternal effects. This conclusion is consistent with IVF studies where the increased pregnancy failure rate in obese women returns to the normal rate if donor oocytes are used instead of autologous oocytes. We postulate that preconceptional weight gain adversely affects pregnancy outcomes and fetal development. In light of our findings, preconceptional counseling may be indicated as the preferable, earlier target for intervention in obese women desiring pregnancy and healthy outcomes. PMID:23152876

Method for Growing Low-Defect Single Crystal Heteroepitaxial Films

NASA Technical Reports Server (NTRS)

Powell, J. Anthony (Inventor); Neudeck, Philip G. (Inventor)

2002-01-01

A method is disclosed for growing high-quality low-defect crystal films heteroepitaxially on substrates that are different than the crystal films. The growth of the first two heteroepitaxial bilayers is performed on a first two-dimensional nucleate island before a second growth of two-dimensional nucleation is allowed to start. The method is particularly suited for the growth of 3C-SiC, 2H-AlN, or 2H-GaN on 6H-SiC, 4H-SiC, or silicon substrates.

Twin-mediated crystal growth: an enigma resolved

PubMed Central

Shahani, Ashwin J.; Gulsoy, E. Begum; Poulsen, Stefan O.; Xiao, Xianghui; Voorhees, Peter W.

2016-01-01

During crystal growth, faceted interfaces may be perturbed by defects, leading to a rich variety of polycrystalline growth forms. One such defect is the coherent Σ3 {111} twin boundary, which is widely known to catalyze crystal growth. These defects have a profound effect on the properties of many materials: for example, electron-hole recombination rates strongly depend on the character of the twin boundaries in polycrystalline Si photovoltaic cells. However, the morphology of the twinned interface during growth has long been a mystery due to the lack of four-dimensional (i.e., space and time resolved) experiments. Many controversial mechanisms have been proposed for this process, most of which lack experimental verification. Here, we probe the real-time interfacial dynamics of polycrystalline Si particles growing from an Al-Si-Cu liquid via synchrotron-based X-ray tomography. Our novel analysis of the time evolution of the interfacial normals allows us to quantify unambiguously the habit plane and grain boundary orientations during growth. This, when combined with direct measurements of the interfacial morphology provide the first confirmation of twin-mediated growth, proposed over 50 years ago. Using the insights provided by these experiments, we have developed a unified picture of the phenomena responsible for the dynamics of faceted Si growth. PMID:27346073

Twin-mediated crystal growth: an enigma resolved

NASA Astrophysics Data System (ADS)

Shahani, Ashwin J.; Gulsoy, E. Begum; Poulsen, Stefan O.; Xiao, Xianghui; Voorhees, Peter W.

2016-06-01

During crystal growth, faceted interfaces may be perturbed by defects, leading to a rich variety of polycrystalline growth forms. One such defect is the coherent Σ3 {111} twin boundary, which is widely known to catalyze crystal growth. These defects have a profound effect on the properties of many materials: for example, electron-hole recombination rates strongly depend on the character of the twin boundaries in polycrystalline Si photovoltaic cells. However, the morphology of the twinned interface during growth has long been a mystery due to the lack of four-dimensional (i.e., space and time resolved) experiments. Many controversial mechanisms have been proposed for this process, most of which lack experimental verification. Here, we probe the real-time interfacial dynamics of polycrystalline Si particles growing from an Al-Si-Cu liquid via synchrotron-based X-ray tomography. Our novel analysis of the time evolution of the interfacial normals allows us to quantify unambiguously the habit plane and grain boundary orientations during growth. This, when combined with direct measurements of the interfacial morphology provide the first confirmation of twin-mediated growth, proposed over 50 years ago. Using the insights provided by these experiments, we have developed a unified picture of the phenomena responsible for the dynamics of faceted Si growth.

The UbiI (VisC) Aerobic Ubiquinone Synthase Is Required for Expression of Type 1 Pili, Biofilm Formation, and Pathogenesis in Uropathogenic Escherichia coli

PubMed Central

Floyd, Kyle A.; Mitchell, Courtney A.; Eberly, Allison R.; Colling, Spencer J.; Zhang, Ellisa W.; DePas, William; Chapman, Matthew R.; Conover, Matthew; Rogers, Bridget R.; Hultgren, Scott J.

2016-01-01

ABSTRACT Uropathogenic Escherichia coli (UPEC), which causes the majority of urinary tract infections (UTI), uses pilus-mediated adherence to initiate biofilm formation in the urinary tract. Oxygen gradients within E. coli biofilms regulate expression and localization of adhesive type 1 pili. A transposon mutant screen for strains defective in biofilm formation identified the ubiI (formerly visC) aerobic ubiquinone synthase gene as critical for UPEC biofilm formation. In this study, we characterized a nonpolar ubiI deletion mutant and compared its behavior to that of wild-type bacteria grown under aerobic and anoxic conditions. Consistent with its function as an aerobic ubiquinone-8 synthase, deletion of ubiI in UPEC resulted in reduced membrane potential, diminished motility, and reduced expression of chaperone-usher pathway pili. Loss of aerobic respiration was previously shown to negatively impact expression of type 1 pili. To determine whether this reduction in type 1 pili was due to an energy deficit, wild-type UPEC and the ubiI mutant were compared for energy-dependent phenotypes under anoxic conditions, in which quinone synthesis is undertaken by anaerobic quinone synthases. Under anoxic conditions, the two strains exhibited wild-type levels of motility but produced diminished numbers of type 1 pili, suggesting that the reduction of type 1 pilus expression in the absence of oxygen is not due to a cellular energy deficit. Acute- and chronic-infection studies in a mouse model of UTI revealed a significant virulence deficit in the ubiI mutant, indicating that UPEC encounters enough oxygen in the bladder to induce aerobic ubiquinone synthesis during infection. IMPORTANCE The majority of urinary tract infections are caused by uropathogenic E. coli, a bacterium that can respire in the presence and absence of oxygen. The bladder environment is hypoxic, with oxygen concentrations ranging from 4% to 7%, compared to 21% atmospheric oxygen. This work provides evidence

The UbiI (VisC) Aerobic Ubiquinone Synthase Is Required for Expression of Type 1 Pili, Biofilm Formation, and Pathogenesis in Uropathogenic Escherichia coli.

PubMed

Floyd, Kyle A; Mitchell, Courtney A; Eberly, Allison R; Colling, Spencer J; Zhang, Ellisa W; DePas, William; Chapman, Matthew R; Conover, Matthew; Rogers, Bridget R; Hultgren, Scott J; Hadjifrangiskou, Maria

2016-10-01

Uropathogenic Escherichia coli (UPEC), which causes the majority of urinary tract infections (UTI), uses pilus-mediated adherence to initiate biofilm formation in the urinary tract. Oxygen gradients within E. coli biofilms regulate expression and localization of adhesive type 1 pili. A transposon mutant screen for strains defective in biofilm formation identified the ubiI (formerly visC) aerobic ubiquinone synthase gene as critical for UPEC biofilm formation. In this study, we characterized a nonpolar ubiI deletion mutant and compared its behavior to that of wild-type bacteria grown under aerobic and anoxic conditions. Consistent with its function as an aerobic ubiquinone-8 synthase, deletion of ubiI in UPEC resulted in reduced membrane potential, diminished motility, and reduced expression of chaperone-usher pathway pili. Loss of aerobic respiration was previously shown to negatively impact expression of type 1 pili. To determine whether this reduction in type 1 pili was due to an energy deficit, wild-type UPEC and the ubiI mutant were compared for energy-dependent phenotypes under anoxic conditions, in which quinone synthesis is undertaken by anaerobic quinone synthases. Under anoxic conditions, the two strains exhibited wild-type levels of motility but produced diminished numbers of type 1 pili, suggesting that the reduction of type 1 pilus expression in the absence of oxygen is not due to a cellular energy deficit. Acute- and chronic-infection studies in a mouse model of UTI revealed a significant virulence deficit in the ubiI mutant, indicating that UPEC encounters enough oxygen in the bladder to induce aerobic ubiquinone synthesis during infection. The majority of urinary tract infections are caused by uropathogenic E. coli, a bacterium that can respire in the presence and absence of oxygen. The bladder environment is hypoxic, with oxygen concentrations ranging from 4% to 7%, compared to 21% atmospheric oxygen. This work provides evidence that aerobic

Guided tissue regeneration and platelet rich growth factor for the treatment of Grade II furcation defects: A randomized double-blinded clinical trial - A pilot study.

PubMed

Jenabian, Niloofar; Haghanifar, Sina; Ehsani, Hodis; Zahedi, Ehsan; Haghpanah, Masumeh

2017-01-01

The treatment of furcation area defects remained as a challenging issue in periodontal treatments. Regeneration treatment of furcation defects is the most discussed periodontal treatment. Although not completely hopeless in prognosis, the presence of the furcation involvement significantly increases the chance of tooth loss. The current research was conductedeto compare theeadditive effect of combined guided tissue regeneration (GTR) and platelet-rich growth factor (PRGF) on the treatment of furcation bony defects. A randomized, triple-blinded, split-mouth study was designed. It included patients with a moderate to severe chronic periodontitis with bilateral Grade II furcation involvement of first or second mandibular molars. Each side of mouth was randomly allocated for the treatment with either Bio-Gide American Society of Anesthesiologists GTR or a PRGF or PRGF by itself. Plaque index, gingival index, vertical clinical attachment level, vertical probing depth, recession depth (REC), horizontal probing depth, fornix to alveolar crest (FAC), fornix to base of defect (FBD), furcation vertical component and furcation horizontal component (FHC) were recorded. The current research was conducted to compare the additive effect of combined GTR and PRGF on treatment of furcation bony defects. Altman's nomogram, Kolmogorov-Smirnov test, Friedman test, general linear model, repeated measures, and paired t -test were used as statistical analysis in this research. P < 0.05 was considered statistically significant. Eight patients were finally enrolled for this study. Overly, general and specific clinical and furcation parameters were improved except REC that was deteriorated insignificantly and FAC improved not significantly. Intergroup comparison revealed better improvement of FHC in GTR/PRGF group ( P = 0.02). A significant improvement in the Grade II furcation defects treated with either GTR or PRGF/GTR was noticed. Further large-scale trials are needed to reveal

Guided tissue regeneration and platelet rich growth factor for the treatment of Grade II furcation defects: A randomized double-blinded clinical trial - A pilot study

PubMed Central

Jenabian, Niloofar; Haghanifar, Sina; Ehsani, Hodis; Zahedi, Ehsan; Haghpanah, Masumeh

2017-01-01

Background: The treatment of furcation area defects remained as a challenging issue in periodontal treatments. Regeneration treatment of furcation defects is the most discussed periodontal treatment. Although not completely hopeless in prognosis, the presence of the furcation involvement significantly increases the chance of tooth loss. The current research was conductedeto compare theeadditive effect of combined guided tissue regeneration (GTR) and platelet-rich growth factor (PRGF) on the treatment of furcation bony defects. Materials and Methods: A randomized, triple-blinded, split-mouth study was designed. It included patients with a moderate to severe chronic periodontitis with bilateral Grade II furcation involvement of first or second mandibular molars. Each side of mouth was randomly allocated for the treatment with either Bio-Gide American Society of Anesthesiologists GTR or a PRGF or PRGF by itself. Plaque index, gingival index, vertical clinical attachment level, vertical probing depth, recession depth (REC), horizontal probing depth, fornix to alveolar crest (FAC), fornix to base of defect (FBD), furcation vertical component and furcation horizontal component (FHC) were recorded. The current research was conducted to compare the additive effect of combined GTR and PRGF on treatment of furcation bony defects. Altman's nomogram, Kolmogorov–Smirnov test, Friedman test, general linear model, repeated measures, and paired t-test were used as statistical analysis in this research. P < 0.05 was considered statistically significant. Results: Eight patients were finally enrolled for this study. Overly, general and specific clinical and furcation parameters were improved except REC that was deteriorated insignificantly and FAC improved not significantly. Intergroup comparison revealed better improvement of FHC in GTR/PRGF group (P = 0.02). Conclusion: A significant improvement in the Grade II furcation defects treated with either GTR or PRGF/GTR was noticed

Growth of and defect reduction in nanoscale materials

DOEpatents

Jensen, Kenneth J [Berkeley, CA; Mickelson, William E [San Francisco, CA; Zettl, Alex K [Kensington, CA

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.

Treatment of HMX-production wastewater in an aerobic granular reactor.

PubMed

Zhang, Jin-Hua; Wang, Min-Hui; Zhu, Xiao-Meng

2013-04-01

Aerobic granules were applied to the treatment of HMX-production wastewater using a gradual domestication method in a SBR. During the process, the granules showed a good settling ability, a high biomass retention rate, and high biological activity. After 40 days of stable operation, aerobic granular sludge performed very effectively in the removal of carbon and nitrogen compounds from HMX-production wastewater. Organic matter removal rates up to 97.57% and nitrogen removal efficiencies up to 80% were achieved during the process. Researchers conclude that using aerobic granules to treat explosive wastewater has good prospects for success.

Aerobic fitness in women and responses to lower body negative pressure

NASA Technical Reports Server (NTRS)

Frey, Mary Anne Bassett; Mathes, Karen L.; Hoffler, G. Wyckliffe

1987-01-01

The role of tolerance to orthostatic stress in the maintenance of high aerobic fitness in women was investigated by examining the responses of heart rate, stroke volume, cardiac output, Heather index of contractility, arterial pressure, peripheral resistance, change in calf circumference, and thoracic impedance of healthy female subjects to lower body negative pressure (LBNP) applied for 5 min at -50 mm Hg or until a subject became presyncopal. The testing protocol involved a stepwise reduction in pressure and consisted of two parts: an LBNP test in supine position followed by a treadmill test to peak aerobic capacity. Women were found to exhibit the same response pattern to LBNP as was previously reported by Convertino et al. (1984) for men. The results do not support the hypothesis that orthostatic tolerance in women is inversely related to aerobic fitness, as demonstrated by a finding that the peak aerobic capacity of subjects who became presyncopal did not differ from the peak of the tolerant subjects, and that hemodynamic responses to LBNPL were not a function of aerobic capacity.

Combined aerobic and resistance training: are there additional benefits for older hypertensive adults?

PubMed Central

Lima, Leandra G.; Bonardi, José T.M.; Campos, Giulliard O.; Bertani, Rodrigo F.; Scher, Luria M.L.; Moriguti, Júlio C.; Ferriolli, Eduardo; Lima, Nereida K.C.

2017-01-01

OBJECTIVES: The objective of this study was to compare the effects of a combination of aerobic and resistance training to those of isolated aerobic training on blood pressure, body composition, and insulin sensitivity in hypertensive older adults. METHOD: Forty-four patients were randomly assigned to the aerobic group, resistance and aerobic group, and control group. Before and after 10 weeks, the following data were obtained: 24-hour ambulatory blood pressure data, abdominal circumference, waist circumference, body mass index, lean mass, fat mass, and insulin sensitivity. The study was conducted with 3 training sessions per week. RESULTS: Comparison revealed significant reductions in the body mass index, abdominal and waist circumferences, and ambulatory blood pressure (24-hour, wakefulness and sleep systolic/diastolic blood pressures) in both the aerobic group and the resistance and aerobic (combined) group. The fat mass only changed in the combined group. There was no difference in the insulin sensitivity in any group. CONCLUSIONS: The combined treatment and aerobic treatment alone were equally effective in reducing the blood pressure, body mass index, and abdominal and waist circumferences, although the addition of the resistance component also helped reduce the fat mass. PMID:28658436

Effect of sludge age on methanogenic and glycogen accumulating organisms in an aerobic granular sludge process fed with methanol and acetate

PubMed Central

Pronk, M; Abbas, B; Kleerebezem, R; van Loosdrecht, M C M

2015-01-01

The influence of sludge age on granular sludge formation and microbial population dynamics in a methanol- and acetate-fed aerobic granular sludge system operated at 35°C was investigated. During anaerobic feeding of the reactor, methanol was initially converted to methane by methylotrophic methanogens. These methanogens were able to withstand the relatively long aeration periods. Lowering the anaerobic solid retention time (SRT) from 17 to 8 days enabled selective removal of the methanogens and prevented unwanted methane formation. In absence of methanogens, methanol was converted aerobically, while granule formation remained stable. At high SRT values (51 days), γ-Proteobacteria were responsible for acetate removal through anaerobic uptake and subsequent aerobic growth on storage polymers formed [so called metabolism of glycogen-accumulating organisms (GAO)]. When lowering the SRT (24 days), Defluviicoccus-related organisms (cluster II) belonging to the α-Proteobacteria outcompeted acetate consuming γ-Proteobacteria at 35°C. DNA from the Defluviicoccus-related organisms in cluster II was not extracted by the standard DNA extraction method but with liquid nitrogen, which showed to be more effective. Remarkably, the two GAO types of organisms grew separately in two clearly different types of granules. This work further highlights the potential of aerobic granular sludge systems to effectively influence the microbial communities through sludge age control in order to optimize the wastewater treatment processes. PMID:26059251

Polytype stability and defects in differently doped bulk SiC

NASA Astrophysics Data System (ADS)

Schmitt, Erwin; Straubinger, Thomas; Rasp, Michael; Vogel, Michael; Wohlfart, Andreas

2008-03-01

In this work, we present recent results on development and production of n-type 4 H bulk material. From previous studies it is evident that inclusions of foreign polytypes can act as origin of severe structural imperfections [N. Schulze, D.L. Barret, G. Pensl, S. Rohmfeld, M. Hundhausen, Mater. Sci. Eng. B 61-62 (1999) 44; D. Hofmann, E. Schmitt, M. Bickermann, M. Kölbl, P.J. Wellmann, A. Winnacker, Mater. Sci. Eng. B 61-62 (1999) 48], accompanied by defects like micropipes, stacking faults and dislocations. For that reason, we have carried out investigations to sustain polytype stability throughout the entire process, including nucleation and subsequent growth. Assisted by numerical calculations the influence of growth conditions, especially with respect to thermal field, Si/C ratio and doping, was examined. Several methods for the evaluation of material properties were applied to determine the quality most precisely, e.g. KOH-defect etching, optical microscopy, electron microscopy, X-ray diffraction and resistivity mapping. The key experience we gained was that moderate growth conditions with reduced temperature gradients are only one prerequisite for the reduction of defect density. Also stoichiometry in the gas phase and its modulation by nitrogen doping have to be taken into account and must be adjusted on the prevailing growth regime. We finally identified an optimized process that initiated a considerable improvement of material quality. Best values for 3″ 4 H wafers show that EPD<5×10 3 cm -2 and MPD<0.1 cm -2 can be achieved.

Transmission electron microscopy study of crystal growth, solid solution, and defect formation: Hollandite and synthetic tremolite

NASA Astrophysics Data System (ADS)

Bozhilov, Krassimir Nikolov

Transmission electron microscopy was applied to study the crystal growth, origin of microstructures, and composition of hollandite and synthetic tremolite. The nonequilibrium shape of hollandite crystals, with reentrant angles between prismatic faces, is interpreted to be due to a multistage growth process and the development of lamellar defects that affect the growth rates of the F-faces. The process of crystal growth can be divided into three phases: (1) development of a core of intergrown romanechite and hollandite structures, (2) topotactic transformation of romanechite to hollandite and development of a lamellar microstructure, and (3) extensive overgrowth of hollandite with a high density of chain multiplicity faults, which alters the shapes of the crystals. The products from time-series of hydrothermal tremolite synthesis experiments from an oxide mixture and by recrystallization from diopside, enstatite, quartz, and water have been characterized. The crystallization starts with rapid, metastable formation of pyroxene and Mg-enriched amphibole. Chain multiplicity faults are low in density. The observed Mg enrichment is due primarily to solid solution involving the magnesio-cummingtonite component, which reaches up to 24 mol% in the initial, metastable growth stage. In products from the final stages of the experiments, the magnesio-cummingtonite component in tremolite varies between 7 and 13 mol%. Formation of monoclinic primitive tremolite is also observed. Experimental recrystallization of pyroxenes to amphibole takes place by a complex, multistage mechanism. The product amphibole crystals have low chain-multiplicity fault densities, which in general are not strongly correlated with variations in the Ca/Mg ratio. The yield of tremolitic amphibole is limited by the sluggishness of diopside hydration and dissolution and the formation of persistent, metastable solid solutions rich in the magnesio-cummingtonite component. Distance Least Squares refinements and

β-alanine Supplementation Fails to Increase Peak Aerobic Power or Ventilatory Threshold in Aerobically Trained Males.

PubMed

Greer, Beau Kjerulf; Katalinas, Matthew E; Shaholli, Danielle M; Gallo, Paul M

2016-01-01

The purpose of the present study was to determine the effect of 30 days of β-alanine supplementation on peak aerobic power and ventilatory threshold (VT) in aerobically fit males. Fourteen males (28.8 ± 9.8 yrs) were assigned to either a β-alanine (SUPP) or placebo (PLAC) group; groups were matched for VT as it was the primary outcome measure. β-alanine supplementation consisted of 3 g/day for 7 days, and 6 g/day for the remaining 23 days. Before and after the supplementation period, subjects performed a continuous, graded cycle ergometry test to determine VO2 peak and VT. Metabolic data were analyzed using a 2 × 2 ANOVA with repeated measures. Thirty days of β-alanine supplementation (SUPP) did not increase VO2 peak (4.05 ± 0.6 vs. 4.14 ± 0.6 L/min) as compared to the placebo (PLAC) group (3.88 ± 0.2 vs. 3.97 ± 0.2 L/min) (p > .05). VT did not significantly improve in either the SUPP (3.21 ± 0.5 vs. 3.33 ± 0.5 L/min) or PLAC (3.19 ± 0.1 vs. 3.20 ± 0.1 L/min) group (p > .05). In conclusion, 30 days of β-alanine supplementation had no effect on VO2 peak or VT in aerobically trained athletes.

Stabilization of waste-activated sludge through the anoxic-aerobic digestion process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hashimoto, S.; Fujita, M.; Terai, K.

1982-08-01

During the aerobic digestion process, the nitrogen which had been embedded in the activated sludge is solubilized to form ammoniacal and nitric nitrogen which are in turn transferred to the liquor and cause the increase of nitrogen loading in the sewage treatment plant. In this study, the anoxic-aerobic sludge digestion system which is a modified form of the conventional aerobic sludge digestion is made up of aerobic and anoxic tanks and are designed to remove both the volatile suspended solids and the total nitrogen (TN) simultaneously. The removal efficiencies of both VSS and TN were investigated by feeding waste-activated sludgemore » continuously and semicontinuously. The maximum percent reduction of both VSS and TN was achieved at a Q /SUB r/ /Q /SUB s/ ratio of 2 in the continuous process. The semicontinuous process was used to improve the nitrogen removal efficiency further. In the semicontinuous process, the VSS reduction efficiency as well as the nitrogen removal efficiency increased remarkably under a constant Q /SUB r/ /Q /SUB s/ ratio of 2. This process also achieved a VSS reduction efficiency higher than the aerobic digestion process (control). It was suggested that the additional anoxic tank enhanced the sludge digestion. Furthermore, the anoxic-aerobic digestion system can be applied to other treatment media like the primary sludge, industrial sludge, animal manure, etc.« less

Stabilization of waste-activated sludge through the anoxic-aerobic digestion process.

PubMed

Hashimoto, S; Fujita, M; Terai, K

1982-08-01

During the aerobic digestion process, the nitrogen which had been embedded in the activated sludge is solubilized to form ammoniacal and nitric nitrogen which are in turn transferred to the liquor and cause the increase of nitrogen loading in the sewage treatment plant. In this study, the anoxic-aerobic sludge digestion system which is a modified form of the conventional aerobic sludge digestion is made up of aerobic and anoxic tanks and are designed to remove both the volatile suspended solids and the total nitrogen (TN) simultaneously. The removal efficiencies of both VSS and TN were investigated by feeding waste-activated sludge continuously and semicontinuously. The maximum percent reduction of both VSS and TN was achieved at a Q(r)/Q(s) ratio of 2 in the continuous process. The semicontinuous process was used to improve the nitrogen removal efficiency further. In the semicontinuous process, the VSS reduction efficiency as well as the nitrogen removal efficiency increased remarkably under a constant Q(r)/Q(s) ratio of 2. This process also achieved a VSS reduction efficiency higher than the aerobic digestion process (control). It was suggested that the additional anoxic tank enhanced the sludge digestion. Furthermore, the anoxic-aerobic digestion system can be applied to other treatment media like the primary sludge, industrial sludge, animal manure, etc.

Aerobic biotransformation of N-nitrosodimethylamine and N-nitrodimethylamine in methane and benzene amended soil columns

NASA Astrophysics Data System (ADS)

Weidhaas, Jennifer; Dupont, R. Ryan