Science.gov

Sample records for growth maintain high

  1. Maintaining High Teacher Morale

    ERIC Educational Resources Information Center

    Protheroe, Nancy

    2006-01-01

    In public education's current environment of high-stakes testing and accountability, principals are constantly engaged in an effort to balance messages to their teachers to achieve ever-higher levels of student learning with appreciation for what they do. As a result, it is not surprising that staff morale is an issue in some schools. The…

  2. Maintaining High Expectations

    ERIC Educational Resources Information Center

    Williams, Roger; Williams, Sherry

    2014-01-01

    Author and husband, Roger Williams, is hearing and signs fluently, and author and wife, Sherry Williams, is deaf and uses both speech and signs, although she is most comfortable signing. As parents of six children--deaf and hearing--they are determined to encourage their children to do their best, and they always set their expectations high. They…

  3. Robust root growth in altered hydrotropic response1 (ahr1) mutant of Arabidopsis is maintained by high rate of cell production at low water potential gradient.

    PubMed

    Salazar-Blas, Amed; Noriega-Calixto, Laura; Campos, María E; Eapen, Delfeena; Cruz-Vázquez, Tania; Castillo-Olamendi, Luis; Sepulveda-Jiménez, Gabriela; Porta, Helena; Dubrovsky, Joseph G; Cassab, Gladys I

    2017-01-01

    Hydrotropism is the directional root growth response determined by water stimulus. In a water potential gradient system (WPGS) the roots of the Arabidopsis wild type have a diminished root growth compared to normal medium (NM). In contrast, the altered hydrotropic response1 (ahr1) mutant roots maintain their robust growth in the same WPGS. The aims of this work were to ascertain how ahr1 roots could sustain growth in the WPGS, with a special focus on the integration of cellular processes involved in the signaling that determines root growth during abiotic stress and their relation to hydrotropism. Cellular analysis of the root apical meristem of ahr1 mutant contrary to the wild type showed an absence of changes in the meristem length, the elongation zone length, the length of fully elongated cells, and the cell cycle duration. The robust and steady root growth of ahr1 seedlings in the WPGS is explained by the mutant capacity to maintain cell production and cell elongation at the same level as in the NM. Analysis of auxin response at a transcriptional level showed that roots of the ahr1 mutant had a lower auxin response when grown in the WPGS, compared to wild type, indicating that auxin signaling participates in attenuation of root growth under water stress conditions. Also, wild type plants exhibited a high increase in proline content while ahr1 mutants showed minimum changes in the Normal Medium→Water Stress Medium (NM→WSM), a lower water potential gradient system than the WPGS. Accordingly, in this condition, gene expression of Δ1-6 Pyrroline-5-Carboxylate Synthetase1 (P5CS1) involved in proline synthesis strongly increased in wild type but not in ahr1 seedlings. The ahr1 phenotype shows unique features since the mutant root cells continue to proliferate and grow in the presence of a progressively negative water potential gradient at a level comparable to wild type growing in the NM. As such, it represents an exceptional resource for understanding

  4. Maintaining rapid growth in moderate-density Escherichia coli fermentations.

    PubMed

    Zawada, James; Swartz, James

    2005-02-20

    A novel feeding strategy that prolongs rapid growth rates for Escherichia coli fermentations to moderately high cell density is presented. High-density fermentations are a common and successful means of producing biological products. However, acetate accumulation can be a substantial problem in these procedures. To avoid this problem, many feeding strategies and host modifications have been developed, but all result in relatively low growth rates. If a faster growth rate could be maintained, the growth phase of the process would be shortened, leading to increased productivity. It is also possible that the subsequent specific production rate could be enhanced by growing the early culture at a faster rate. We have developed a procedure to enable rapid growth to a cell density of 20 g/L and have used cell-free protein synthesis to evaluate the relative potential of the resulting cells for producing recombinant proteins. The method uses glucose pulses and the duration of the dissolved oxygen response to calculate the appropriate glucose feed rate based on the glucose demand of the culture. Amino acids and vitamins were supplied in the medium to increase the growth rate. We were able to sustain a growth rate of 0.8/h up to 20 g/L dry cell weight without significant acetate accumulation. Analysis of amino acid consumption indicates that cell composition is an accurate predictor of amino acid demand for most amino acids. Cell-free protein synthesis was used to compare the protein production potential of the high-density cultures with that of cells grown in complex medium and harvested at low cell density and maximum growth rate. Protein production for the extract from the controlled, high-density fermentations was 950 mg/L compared with 860 mg/L for the low-density control. Therefore, the new control procedure has promising potential for developing rapid and productive industrial fermentations.

  5. Rice potassium transporter OsHAK1 is essential for maintaining potassium-mediated growth and functions in salt tolerance over low and high potassium concentration ranges.

    PubMed

    Chen, Guang; Hu, Qingdi; Luo, Le; Yang, Tianyuan; Zhang, Song; Hu, Yibing; Yu, Ling; Xu, Guohua

    2015-12-01

    Potassium (K) absorption and translocation in plants rely upon multiple K transporters for adapting varied K supply and saline conditions. Here, we report the expression patterns and physiological roles of OsHAK1, a member belonging to the KT/KUP/HAK gene family in rice (Oryza sativa L.). The expression of OsHAK1 is up-regulated by K deficiency or salt stress in various tissues, particularly in the root and shoot apical meristem, the epidermises and steles of root, and vascular bundles of shoot. Both oshak1 knockout mutants in comparison to their respective Dongjin or Manan wild types showed a dramatic reduction in K concentration and stunted root and shoot growth. Knockout of OsHAK1 reduced the K absorption rate of unit root surface area by ∼50-55 and ∼30%, and total K uptake by ∼80 and ∼65% at 0.05-0.1 and 1 mm K supply level, respectively. The root net high-affinity K uptake of oshak1 mutants was sensitive to salt stress but not to ammonium supply. Overexpression of OsHAK1 in rice increased K uptake and K/Na ratio. The positive relationship between K concentration and shoot biomass in the mutants suggests that OsHAK1 plays an essential role in K-mediated rice growth and salt tolerance over low and high K concentration ranges.

  6. Human STEAP3 maintains tumor growth under hypoferric condition

    SciTech Connect

    Isobe, Taichi; Baba, Eishi; Arita, Shuji; Komoda, Masato; Tamura, Shingo; Shirakawa, Tsuyoshi; Ariyama, Hiroshi; Takaishi, Shigeo; Kusaba, Hitoshi; and others

    2011-11-01

    Iron is essential in cellular proliferation and survival based on its crucial roles in DNA and ATP synthesis. Tumor cells proliferate rapidly even in patients with low serum iron, although their actual mechanisms are not well known. To elucidate molecular mechanisms of efficient tumor progression under the hypoferric condition, we studied the roles of six-transmembrane epithelial antigen of the prostate family member 3 (STEAP3), which was reported to facilitate iron uptake. Using Raji cells with low STEAP3 mRNA expression, human STEAP3-overexpressing cells were established. The impact of STEAP3 expression was analyzed about the amount of iron storage, the survival under hypoferric conditions in vitro and the growth of tumor in vivo. STEAP3 overexpression increased ferritin, an indicator of iron storage, in STEAP3-overexpressing Raji cells. STEAP3 gave Raji cells the resistance to iron deprivation-induced apoptosis. These STEAP3-overexpressing Raji cells preserved efficient growth even in hypoferric mice, while parental Raji cells grew less rapidly. In addition, iron deficiency enhanced STEAP3 mRNA expression in tumor cells. Furthermore, human colorectal cancer tissues exhibited more STEAP3 mRNA expression and iron storage compared with normal colon mucosa. These findings indicate that STEAP3 maintains iron storage in human malignant cells and tumor proliferation under the hypoferric condition. -- Highlights: {yields} STEAP3 expression results in increment of stored intracellular iron. {yields} Iron deprivation induces expression of STEAP3. {yields} Colorectal cancer expresses STEAP3 highly and stores iron much. {yields} STEAP3 expressing tumors preserves growth even in mice being hypoferremia.

  7. IPP5 inhibits neurite growth in primary sensory neurons by maintaining TGF-β/Smad signaling.

    PubMed

    Han, Qing-Jian; Gao, Nan-Nan; Guo-QiangMa; Zhang, Zhen-Ning; Yu, Wen-Hui; Pan, Jing; Wang, Qiong; Zhang, Xu; Bao, Lan

    2013-01-15

    During nerve regeneration, neurite growth is regulated by both intrinsic molecules and extracellular factors. Here, we found that inhibitor 5 of protein phosphatase 1 (IPP5), a newly identified inhibitory subunit of protein phosphatase 1 (PP1), inhibited neurite growth in primary sensory neurons as an intrinsic regulator. IPP5 was highly expressed in the primary sensory neurons of rat dorsal root ganglion (DRG) and was downregulated after sciatic nerve axotomy. Knocking down IPP5 with specific shRNA increased the length of the longest neurite, the total neurite length and the number of neurite ends in cultured rat DRG neurons. Mutation of the PP1-docking motif K(8)IQF(11) or the PP1-inhibiting motif at Thr(34) eliminated the IPP5-induced inhibition of neurite growth. Furthermore, biochemical experiments showed that IPP5 interacted with type I transforming growth factor-β receptor (TβRI) and PP1 and enhanced transforming growth factor-β (TGF-β)/Smad signaling in a PP1-dependent manner. Overexpressing IPP5 in DRG neurons aggravated TGF-β-induced inhibition of neurite growth, which was abolished by blocking PP1 or IPP5 binding to PP1. Blockage of TGF-β signaling with the TβRI inhibitor SB431542 or Smad2 shRNA attenuated the IPP5-induced inhibition of neurite growth. Thus, these data indicate that selectively expressed IPP5 inhibits neurite growth by maintaining TGF-β signaling in primary sensory neurons.

  8. A control system for maintaining high stability in gas pressure

    SciTech Connect

    Wuest, C.R.; Hendricks, C.D.

    1987-09-01

    A pressure control system has been implemented on an experiment designed to detect the presence of fractional charges in bulk matter. The experiment utilizes a liquid-droplet generation technique requiring high-stability gas-pressure delivery to ensure accurate data collection. The pressure control system consists of a pressurized mercury reservoir containing a low-vapor-pressure, diffusion-pump oil. A commercially available differential pressure transducer, servo-driven valve, and controller sense the pressure fluctuations with respect to a static reference pressure. The system can maintain constant pressure to better than one part in 10,000 at working pressures in the range of 100 to 300 psi. 3 refs., 7 figs.

  9. Propagation of Optical Pulses in Polarization Maintaining Highly Birefringent Fibers

    NASA Astrophysics Data System (ADS)

    Leiva, Ariel; Olivares, Ricardo

    2008-04-01

    The propagation of Gaussian optical pulses through optical PM-HiBi (Polarization Maintaining Highly Birefringent) fibers is analyzed and simulated. Based upon a model of propagation as described by Marcuse, et al., [1] and Sunnerud, et al., [2], and the use of PMD (Polarization Mode Dispersion) compensators and emulators used by Kogelnik, et al. [2], [3] and Lima, et al. [4], we construct a simple model that allows graphical representation of the distortion experienced by optical pulses when propagating in a PM-HiBi fiber for different initial polarizations. The results of our analysis have the benefit of being identical to the more elaborate models of [1], [2], while also providing the additional advantage of simple graphical representation.

  10. Maintaining a permanent plot data base for growth and yield research: Solutions to some recurring problems

    Treesearch

    John C. Byrne

    1993-01-01

    Methods for solving some recurring problems of maintaining a permanent plot data base for growth and yield reseuch are described. These methods include documenting data from diverse sampling designs, changing sampling designs, changing field procedures, and coordinating activities in the plots with the land management agency. Managing a permanent plot data base (...

  11. Reduction of translating ribosomes enables Escherichia coli to maintain elongation rates during slow growth

    PubMed Central

    Dai, Xiongfeng; Zhu, Manlu; Warren, Mya; Balakrishnan, Rohan; Patsalo, Vadim; Okano, Hiroyuki; Williamson, James R.; Fredrick, Kurt; Wang, Yi-Ping; Hwa, Terence

    2017-01-01

    Bacteria growing in different conditions experience a broad range of demand on the rate of protein synthesis which profoundly affects cellular resource allocation. During fast growth, protein synthesis is long known to be modulated by adjusting the ribosome content, with the vast majority of ribosomes engaged at a near-maximal rate of elongation. Here we characterized protein synthesis by E. coli systematically, focusing on slow growth conditions. We establish that the translational elongation rate decreases as growth slows down, exhibiting a Michaelis-Menten dependence on the abundance of the cellular translational apparatus. However, an appreciable elongation rate is maintained even towards zero growth including the stationary phase. This maintenance, critical for timely protein synthesis in harsh environments, is accompanied by a drastic reduction in the fraction of active ribosomes. Interestingly, well-known antibiotics such as chloramphenicol also cause substantial reduction in the pool of active ribosomes, instead of slowing down translational elongation as commonly thought. PMID:27941827

  12. Reduction of translating ribosomes enables Escherichia coli to maintain elongation rates during slow growth.

    PubMed

    Dai, Xiongfeng; Zhu, Manlu; Warren, Mya; Balakrishnan, Rohan; Patsalo, Vadim; Okano, Hiroyuki; Williamson, James R; Fredrick, Kurt; Wang, Yi-Ping; Hwa, Terence

    2016-12-12

    Bacteria growing under different conditions experience a broad range of demand on the rate of protein synthesis, which profoundly affects cellular resource allocation. During fast growth, protein synthesis has long been known to be modulated by adjusting the ribosome content, with the vast majority of ribosomes engaged at a near-maximal rate of elongation. Here, we systematically characterize protein synthesis by Escherichia coli, focusing on slow-growth conditions. We establish that the translational elongation rate decreases as growth slows, exhibiting a Michaelis-Menten dependence on the abundance of the cellular translational apparatus. However, an appreciable elongation rate is maintained even towards zero growth, including the stationary phase. This maintenance, critical for timely protein synthesis in harsh environments, is accompanied by a drastic reduction in the fraction of active ribosomes. Interestingly, well-known antibiotics such as chloramphenicol also cause a substantial reduction in the pool of active ribosomes, instead of slowing down translational elongation as commonly thought.

  13. Predictors of maintained high-risk behaviors among impoverished women.

    PubMed Central

    Nyamathi, A M; Bennett, C; Leake, B

    1995-01-01

    The researchers sought to explore and describe the demographic, cognitive, psychosocial, and behavioral factors associated with the continued risky behavior of a convenience sample of homeless and drug-addicted women two to four weeks after they had completed an AIDS education program. The sample included 942 crack users and 767 women who had multiple sex partners. Analyses revealed that impoverished women who maintained multiple sexual partners were less likely to be in drug recovery programs than in homeless shelters. They were more likely to share needles and be involved sexually with male injection drug users compared with impoverished women who did not maintain multiple sexual partners. Persistent crack users were older than those who reported cessation of crack use, were more often African American, and were more likely to have sex partners who were injecting drug users. Women who demonstrated less improvement in depression and distress scores, concerns, use of affective coping, appraisal of threat, and social support were more likely to maintain crack use and multiple partners. The study's implications for the design of intervention programs aimed at risk reduction based on ethnicity are discussed. PMID:7480615

  14. Prox1 maintains muscle structure and growth in the developing heart

    PubMed Central

    Risebro, Catherine A.; Searles, Richelle G.; Melville, Athalie A. D.; Ehler, Elisabeth; Jina, Nipurna; Shah, Sonia; Pallas, Jacky; Hubank, Mike; Dillard, Miriam; Harvey, Natasha L.; Schwartz, Robert J.; Chien, Kenneth R.; Oliver, Guillermo; Riley, Paul R.

    2009-01-01

    Summary Impaired cardiac muscle growth and aberrant myocyte arrangement underlie congenital heart disease and cardiomyopathy. We show that cardiac-specific inactivation of the murine homeobox transcription factor Prox1 results in the disruption of expression and localisation of sarcomeric proteins, gross myofibril disarray and growth-retarded hearts. Furthermore, we demonstrate that Prox1 is required for direct transcriptional regulation of the genes encoding the structural proteins α-actinin, N-RAP and zyxin, which collectively function to maintain an actin-α-actinin interaction as the fundamental association of the sarcomere. Aspects of abnormal heart development and the manifestation of a subset of muscular-based disease have previously been attributed to mutations in key structural proteins. Our study reveals an essential requirement for direct transcriptional regulation of sarcomere integrity, in the context of enabling foetal cardiomyocyte hypertrophy, maintenance of contractile function and progression towards inherited or acquired myopathic disease. PMID:19091769

  15. Prox1 maintains muscle structure and growth in the developing heart.

    PubMed

    Risebro, Catherine A; Searles, Richelle G; Melville, Athalie A D; Ehler, Elisabeth; Jina, Nipurna; Shah, Sonia; Pallas, Jacky; Hubank, Mike; Dillard, Miriam; Harvey, Natasha L; Schwartz, Robert J; Chien, Kenneth R; Oliver, Guillermo; Riley, Paul R

    2009-02-01

    Impaired cardiac muscle growth and aberrant myocyte arrangement underlie congenital heart disease and cardiomyopathy. We show that cardiac-specific inactivation of the murine homeobox transcription factor Prox1 results in the disruption of expression and localisation of sarcomeric proteins, gross myofibril disarray and growth-retarded hearts. Furthermore, we demonstrate that Prox1 is required for direct transcriptional regulation of the genes encoding the structural proteins alpha-actinin, N-RAP and zyxin, which collectively function to maintain an actin-alpha-actinin interaction as the fundamental association of the sarcomere. Aspects of abnormal heart development and the manifestation of a subset of muscular-based disease have previously been attributed to mutations in key structural proteins. Our study reveals an essential requirement for direct transcriptional regulation of sarcomere integrity, in the context of enabling foetal cardiomyocyte hypertrophy, maintenance of contractile function and progression towards inherited or acquired myopathic disease.

  16. The High School Writing Center: Establishing and Maintaining One.

    ERIC Educational Resources Information Center

    Farrell, Pamela B., Ed.

    Focusing on high school writing centers, this collection of essays discusses a variety of issues associated with the writing center, including the process of securing the principal's support, setting goals, working out physical arrangements, training tutors and professional staff, fostering student participation, and record keeping. Essays and…

  17. Maintaining High-Performance Schools after Construction or Renovation

    ERIC Educational Resources Information Center

    Luepke, Gary; Ronsivalli, Louis J., Jr.

    2009-01-01

    With taxpayers' considerable investment in schools, it is critical for school districts to preserve their community's assets with new construction or renovation and effective facility maintenance programs. "High-performance" school buildings are designed to link the physical environment to positive student achievement while providing such benefits…

  18. Review of "Do High Flyers Maintain Their Altitude?"

    ERIC Educational Resources Information Center

    Lee, Jaekyung

    2011-01-01

    The research report reviewed here concludes that many initially high-achieving students are falling further and further behind over the course of their years in school. The report intends to raise the alarm and to advocate for improved programs for these students. It is, however, a false alarm due to biased methodology and misleading arguments.…

  19. A polarisation maintaining fiber optimized for high temperature gyroscopes

    NASA Astrophysics Data System (ADS)

    Tutu, F.; Hill, Mark; Cooper, Laurence; Gillooly, A.

    2015-05-01

    Fiber optic gyroscopes (FOGs) are being used within increasingly severe environments, requiring operational temperatures in excess of the standard operating range for FOGs. Applications requiring these higher temperatures include: directional drilling of wells in oil and gas fields, space applications and military FOG applications. This paper will describe the relative merits of two high temperature acrylate coatings for an optical fiber designed for a FOG in such operating environments. Results for two high temperature acrylates are presented, tested in a 200m length of loose wound fiber, coiled and supported at 75mm diameter, in line with TIA/EIA-455-192 (FOTP-192). It can be seen that both coating types give very good polarization extinction ratio (PER) performance at high temperature up to 180oC, with better performance shown by one coating type on the low temperature side, since it does not harden to the same extent below 0oC. The long term thermal exposure effects will be discussed and experimental results presented which include testing the PER performance over temperature both before and after an extended period of high temperature endurance. This will demonstrate the relative merits of different styles of coatings. From the PER performance, the h-parameter of the fiber can be calculated and hence the preferred coating type selected and recommended for the customer operating environment.

  20. Maintaining viability of white clover under very high pressure

    NASA Astrophysics Data System (ADS)

    Nishihira, N.; Iwasaki, T.; Shinpou, R.; Hara, A.; Ono, F.; Hada, Y.; Mori, Y.; Takarabe, K.; Saigusa, M.; Matsushima, Y.; Saini, N. L.; Yamashita, M.

    2012-06-01

    The high pressure technique developed in physics may give a new possibility if it is applied to a biological study. We have been studying the tolerance of small living samples such as planktons and mosses, and found that all of them were alive after exposed to extremely high hydrostatic pressure of 7.5 GPa. This technique has been extended to a higher plant Trifolium lepens L. (white clover). A few seeds of white clover were exposed to 7.5 GPa for up to 6 days. After the pressure was released, they were seeded on agar, or directly on sowing soil. Seventeen out of the total 22 seeds exposed to the high pressure were found to be alive. Those exposed for up to 1 day and seeded on agar germinated roots. Those exposed for up to 1 h and seeded on soil germinated stems and leaves. The present technique has the possibility of being applied to improve breed of plants and to discover a very strong species that stands against very severe environmental conditions.

  1. Invaders do not require high resource levels to maintain physiological advantages in a temperate deciduous forest.

    PubMed

    Heberling, J Mason; Fridley, Jason D

    2016-04-01

    Non-native, invasive plants are commonly typified by trait strategies associated with high resource demands and plant invasions are often thought to be dependent upon site resource availability or disturbance. However, the invasion of shade-tolerant woody species into deciduous forests of the Eastern United States seems to contradict such generalization, as growth in this ecosystem is strongly constrained by light and, secondarily, nutrient stress. In a factorial manipulation of light and soil nitrogen availability, we established an experimental resource gradient in a secondary deciduous forest to test whether three common, woody, invasive species displayed increased metabolic performance and biomass production compared to six co-occurring woody native species, and whether these predicted differences depend upon resource supply. Using hierarchical Bayesian models of photosynthesis that included leaf trait effects, we found that invasive species exhibited functional strategies associated with higher rates of carbon gain. Further, invader metabolic and growth-related attributes were more responsive to increasing light availability than those of natives, but did not fall below average native responses even in low light. Surprisingly, neither group showed direct trait or growth responses to soil N additions. However, invasive species showed increased photosynthetic nitrogen use efficiencies with decreasing N availability, while that of natives remained constant. Although invader advantage over natives was amplified in higher resource conditions in this forest, our results indicate that some invasive species can maintain physiological advantages over co-occurring natives regardless of resource conditions.

  2. A Convenient and Efficient Method to Enrich and Maintain Highly Proliferative Human Fetal Liver Stem Cells.

    PubMed

    Guo, Xuan; Wang, Shu; Dou, Ya-ling; Guo, Xiang-fei; Chen, Zhao-li; Wang, Xin-wei; Shen, Zhi-qiang; Qiu, Zhi-gang; Jin, Min; Li, Jun-wen

    2015-06-01

    Pluripotent human hepatic stem cells have broad research and clinical applications, which are, however, restricted by both limited resources and technical difficulties with respect to isolation of stem cells from the adult or fetal liver. In this study, we developed a convenient and efficient method involving a two-step in situ collagenase perfusion, gravity sedimentation, and Percoll density gradient centrifugation to enrich and maintain highly proliferative human fetal liver stem cells (hFLSCs). Using this method, the isolated hFLSCs entered into the exponential growth phase within 10 days and maintained sufficient proliferative activity to permit subculture for at least 20 passages without differentiation. Immunocytochemistry, immunofluorescence, and flow cytometry results showed that these cells expressed stem cell markers, such as c-kit, CD44, epithelial cell adhesion molecule (EpCAM), oval cell marker-6 (OV-6), epithelial marker cytokeratin 18 (CK18), biliary ductal marker CK19, and alpha-fetoprotein (AFP). Gene expression analysis showed that these cells had stable mRNA expression of c-Kit, EpCAM, neural cell adhesion molecule (NCAM), CK19, CK18, AFP, and claudin 3 (CLDN-3) throughout each passage while maintaining low levels of ALB, but with complete absence of cytochrome P450 3A4 (C3A4), phosphoenolpyruvate carboxykinase (PEPCK), telomeric repeat binding factor (TRF), and connexin 26 (CX26) expression. When grown in appropriate medium, these isolated liver stem cells could differentiate into hepatocytes, cholangiocytes, osteoblasts, adipocytes, or endothelial cells. Thus, we have demonstrated a more economical and efficient method to isolate hFLSCs than magnetic-activated cell sorting (MACS). This novel approach may provide an excellent tool to isolate highly proliferative hFLSCs for tissue engineering and regenerative therapies.

  3. Maintaining high-Q in an optical microresonator coated with high-aspect-ratio gold nanorods

    NASA Astrophysics Data System (ADS)

    Ganta, D.; Dale, E. B.; Rosenberger, A. T.

    2013-10-01

    We report methods to coat fused-silica microresonators with solution-grown high-aspect-ratio (AR) gold nanorods (NRs). Microresonators coated using our method maintain an optical quality factor (Q) greater than 107 after coating. The more successful method involves silanization of the surface of the microresonator with 3-mercaptopropylmethyldimethoxysilane (MPMDMS), to enable the adhesion of gold NRs. The high-AR NR-coated microresonator combines the field enhancement of localized surface plasmon resonances with the cavity-enhanced evanescent components of high-Q whispering-gallery modes, making it useful for plasmonic sensing applications in the infrared. By coating with NRs having a different aspect ratio, the enhancement regime can be selected within a wide range of wavelengths.

  4. Voluntary Running Aids to Maintain High Body Temperature in Rats Bred for High Aerobic Capacity

    PubMed Central

    Karvinen, Sira M.; Silvennoinen, Mika; Ma, Hongqiang; Törmäkangas, Timo; Rantalainen, Timo; Rinnankoski-Tuikka, Rita; Lensu, Sanna; Koch, Lauren G.; Britton, Steven L.; Kainulainen, Heikki

    2016-01-01

    The production of heat, i.e., thermogenesis, is a significant component of the metabolic rate, which in turn affects weight gain and health. Thermogenesis is linked to physical activity (PA) level. However, it is not known whether intrinsic exercise capacity, aging, and long-term voluntary running affect core body temperature. Here we use rat models selectively bred to differ in maximal treadmill endurance running capacity (Low capacity runners, LCR and High capacity Runners, HCR), that as adults are divergent for aerobic exercise capacity, aging, and metabolic disease risk to study the connection between PA and body temperature. Ten high capacity runner (HCR) and ten low capacity runner (LCR) female rats were studied between 9 and 21 months of age. Rectal body temperature of HCR and LCR rats was measured before and after 1-year voluntary running/control intervention to explore the effects of aging and PA. Also, we determined whether injected glucose and spontaneous activity affect the body temperature differently between LCR and HCR rats at 9 vs. 21 months of age. HCRs had on average 1.3°C higher body temperature than LCRs (p < 0.001). Aging decreased the body temperature level of HCRs to similar levels with LCRs. The opportunity to run voluntarily had a significant impact on the body temperature of HCRs (p < 0.001) allowing them to maintain body temperature at a similar level as when at younger age. Compared to LCRs, HCRs were spontaneously more active, had higher relative gastrocnemius muscle mass and higher UCP2, PGC-1α, cyt c, and OXPHOS levels in the skeletal muscle (p < 0.050). These results suggest that higher PA level together with greater relative muscle mass and higher mitochondrial content/function contribute to the accumulation of heat in the HCRs. Interestingly, neither aging nor voluntary training had a significant impact on core body temperature of LCRs. However, glucose injection resulted in a lowering of the body temperature of LCRs (p < 0

  5. Voluntary Running Aids to Maintain High Body Temperature in Rats Bred for High Aerobic Capacity.

    PubMed

    Karvinen, Sira M; Silvennoinen, Mika; Ma, Hongqiang; Törmäkangas, Timo; Rantalainen, Timo; Rinnankoski-Tuikka, Rita; Lensu, Sanna; Koch, Lauren G; Britton, Steven L; Kainulainen, Heikki

    2016-01-01

    The production of heat, i.e., thermogenesis, is a significant component of the metabolic rate, which in turn affects weight gain and health. Thermogenesis is linked to physical activity (PA) level. However, it is not known whether intrinsic exercise capacity, aging, and long-term voluntary running affect core body temperature. Here we use rat models selectively bred to differ in maximal treadmill endurance running capacity (Low capacity runners, LCR and High capacity Runners, HCR), that as adults are divergent for aerobic exercise capacity, aging, and metabolic disease risk to study the connection between PA and body temperature. Ten high capacity runner (HCR) and ten low capacity runner (LCR) female rats were studied between 9 and 21 months of age. Rectal body temperature of HCR and LCR rats was measured before and after 1-year voluntary running/control intervention to explore the effects of aging and PA. Also, we determined whether injected glucose and spontaneous activity affect the body temperature differently between LCR and HCR rats at 9 vs. 21 months of age. HCRs had on average 1.3°C higher body temperature than LCRs (p < 0.001). Aging decreased the body temperature level of HCRs to similar levels with LCRs. The opportunity to run voluntarily had a significant impact on the body temperature of HCRs (p < 0.001) allowing them to maintain body temperature at a similar level as when at younger age. Compared to LCRs, HCRs were spontaneously more active, had higher relative gastrocnemius muscle mass and higher UCP2, PGC-1α, cyt c, and OXPHOS levels in the skeletal muscle (p < 0.050). These results suggest that higher PA level together with greater relative muscle mass and higher mitochondrial content/function contribute to the accumulation of heat in the HCRs. Interestingly, neither aging nor voluntary training had a significant impact on core body temperature of LCRs. However, glucose injection resulted in a lowering of the body temperature of LCRs (p < 0

  6. Academic Achievement in First-Year University: Who Maintains Their High School Average?

    ERIC Educational Resources Information Center

    Wintre, Maxine Gallander; Dilouya, Barry; Pancer, S. Mark; Pratt, Michael W.; Birnie-Lefcovitch, Shelly; Polivy, Janet; Adams, Gerald

    2011-01-01

    The present study investigates the characteristics which differentiate between first-year university students who maintain their high school averages (Maintainers: n = 165) and those whose averages decrease at least one letter grade (Decliners: n = 435). The 600 students entered first year at one of six Canadian Universities, which varied in size…

  7. Academic Achievement in First-Year University: Who Maintains Their High School Average?

    ERIC Educational Resources Information Center

    Wintre, Maxine Gallander; Dilouya, Barry; Pancer, S. Mark; Pratt, Michael W.; Birnie-Lefcovitch, Shelly; Polivy, Janet; Adams, Gerald

    2011-01-01

    The present study investigates the characteristics which differentiate between first-year university students who maintain their high school averages (Maintainers: n = 165) and those whose averages decrease at least one letter grade (Decliners: n = 435). The 600 students entered first year at one of six Canadian Universities, which varied in size…

  8. TIF-IA-dependent regulation of ribosome synthesis in drosophila muscle is required to maintain systemic insulin signaling and larval growth.

    PubMed

    Ghosh, Abhishek; Rideout, Elizabeth J; Grewal, Savraj S

    2014-10-01

    The conserved TOR kinase signaling network links nutrient availability to cell, tissue and body growth in animals. One important growth-regulatory target of TOR signaling is ribosome biogenesis. Studies in yeast and mammalian cell culture have described how TOR controls rRNA synthesis-a limiting step in ribosome biogenesis-via the RNA Polymerase I transcription factor TIF-IA. However, the contribution of TOR-dependent ribosome synthesis to tissue and body growth in animals is less clear. Here we show in Drosophila larvae that ribosome synthesis in muscle is required non-autonomously to maintain normal body growth and development. We find that amino acid starvation and TOR inhibition lead to reduced levels of TIF-IA, and decreased rRNA synthesis in larval muscle. When we mimic this decrease in muscle ribosome synthesis using RNAi-mediated knockdown of TIF-IA, we observe delayed larval development and reduced body growth. This reduction in growth is caused by lowered systemic insulin signaling via two endocrine responses: reduced expression of Drosophila insulin-like peptides (dILPs) from the brain and increased expression of Imp-L2-a secreted factor that binds and inhibits dILP activity-from muscle. We also observed that maintaining TIF-IA levels in muscle could partially reverse the starvation-mediated suppression of systemic insulin signaling. Finally, we show that activation of TOR specifically in muscle can increase overall body size and this effect requires TIF-IA function. These data suggest that muscle ribosome synthesis functions as a nutrient-dependent checkpoint for overall body growth: in nutrient rich conditions, TOR is required to maintain levels of TIF-IA and ribosome synthesis to promote high levels of systemic insulin, but under conditions of starvation stress, reduced muscle ribosome synthesis triggers an endocrine response that limits systemic insulin signaling to restrict growth and maintain homeostasis.

  9. TIF-IA-Dependent Regulation of Ribosome Synthesis in Drosophila Muscle Is Required to Maintain Systemic Insulin Signaling and Larval Growth

    PubMed Central

    Ghosh, Abhishek; Rideout, Elizabeth J.; Grewal, Savraj S.

    2014-01-01

    The conserved TOR kinase signaling network links nutrient availability to cell, tissue and body growth in animals. One important growth-regulatory target of TOR signaling is ribosome biogenesis. Studies in yeast and mammalian cell culture have described how TOR controls rRNA synthesis—a limiting step in ribosome biogenesis—via the RNA Polymerase I transcription factor TIF-IA. However, the contribution of TOR-dependent ribosome synthesis to tissue and body growth in animals is less clear. Here we show in Drosophila larvae that ribosome synthesis in muscle is required non-autonomously to maintain normal body growth and development. We find that amino acid starvation and TOR inhibition lead to reduced levels of TIF-IA, and decreased rRNA synthesis in larval muscle. When we mimic this decrease in muscle ribosome synthesis using RNAi-mediated knockdown of TIF-IA, we observe delayed larval development and reduced body growth. This reduction in growth is caused by lowered systemic insulin signaling via two endocrine responses: reduced expression of Drosophila insulin-like peptides (dILPs) from the brain and increased expression of Imp-L2—a secreted factor that binds and inhibits dILP activity—from muscle. We also observed that maintaining TIF-IA levels in muscle could partially reverse the starvation-mediated suppression of systemic insulin signaling. Finally, we show that activation of TOR specifically in muscle can increase overall body size and this effect requires TIF-IA function. These data suggest that muscle ribosome synthesis functions as a nutrient-dependent checkpoint for overall body growth: in nutrient rich conditions, TOR is required to maintain levels of TIF-IA and ribosome synthesis to promote high levels of systemic insulin, but under conditions of starvation stress, reduced muscle ribosome synthesis triggers an endocrine response that limits systemic insulin signaling to restrict growth and maintain homeostasis. PMID:25356674

  10. Lactobacillus plantarum strain maintains growth of infant mice during chronic undernutrition.

    PubMed

    Schwarzer, Martin; Makki, Kassem; Storelli, Gilles; Machuca-Gayet, Irma; Srutkova, Dagmar; Hermanova, Petra; Martino, Maria Elena; Balmand, Severine; Hudcovic, Tomas; Heddi, Abdelaziz; Rieusset, Jennifer; Kozakova, Hana; Vidal, Hubert; Leulier, François

    2016-02-19

    In most animal species, juvenile growth is marked by an exponential gain in body weight and size. Here we show that the microbiota of infant mice sustains both weight gain and longitudinal growth when mice are fed a standard laboratory mouse diet or a nutritionally depleted diet. We found that the intestinal microbiota interacts with the somatotropic hormone axis to drive systemic growth. Using monocolonized mouse models, we showed that selected lactobacilli promoted juvenile growth in a strain-dependent manner that recapitulated the microbiota's effect on growth and the somatotropic axis. These findings show that the host's microbiota supports juvenile growth. Moreover, we discovered that lactobacilli strains buffered the adverse effects of chronic undernutrition on the postnatal growth of germ-free mice.

  11. Transgenic Chickens Overexpressing Aromatase Have High Estrogen Levels but Maintain a Predominantly Male Phenotype.

    PubMed

    Lambeth, Luke S; Morris, Kirsten R; Wise, Terry G; Cummins, David M; O'Neil, Terri E; Cao, Yu; Sinclair, Andrew H; Doran, Timothy J; Smith, Craig A

    2016-01-01

    Estrogens play a key role in sexual differentiation of both the gonads and external traits in birds. The production of estrogen occurs via a well-characterized steroidogenic pathway, which is a multistep process involving several enzymes, including cytochrome P450 aromatase. In chicken embryos, the aromatase gene (CYP19A1) is expressed female-specifically from the time of gonadal sex differentiation. Ectopic overexpression of aromatase in male chicken embryos induces gonadal sex reversal, and male embryos treated with estradiol become feminized; however, this is not permanent. To test whether a continuous supply of estrogen in adult chickens could induce stable male to female sex reversal, 2 transgenic male chickens overexpressing aromatase were generated using the Tol2/transposase system. These birds had robust ectopic aromatase expression, which resulted in the production of high serum levels of estradiol. Transgenic males had female-like wattle and comb growth and feathering, but they retained male weights, displayed leg spurs, and developed testes. Despite the small sample size, this data strongly suggests that high levels of circulating estrogen are insufficient to maintain a female gonadal phenotype in adult birds. Previous observations of gynandromorph birds and embryos with mixed sex chimeric gonads have highlighted the role of cell autonomous sex identity in chickens. This might imply that in the study described here, direct genetic effects of the male chromosomes largely prevailed over the hormonal profile of the aromatase transgenic birds. This data therefore support the emerging view of at least partial cell autonomous sex development in birds. However, a larger study will confirm this intriguing observation.

  12. Coordinated regulation of photosynthetic and respiratory components is necessary to maintain chloroplast energy balance in varied growth conditions.

    PubMed

    Dahal, Keshav; Martyn, Greg D; Alber, Nicole A; Vanlerberghe, Greg C

    2017-01-01

    Mitochondria have a non-energy-conserving alternative oxidase (AOX) proposed to support photosynthesis, perhaps by promoting energy balance under varying growth conditions. To investigate this, wild-type (WT) Nicotiana tabacum were compared with AOX knockdown and overexpression lines. In addition, the amount of AOX protein in WT plants was compared with that of chloroplast light-harvesting complex II (LHCB2), whose amount is known to respond to chloroplast energy status. With increased growth irradiance, WT leaves maintained higher rates of respiration in the light (RL), but no differences in RL or photosynthesis were seen between the WT and transgenic lines, suggesting that, under non-stress conditions, AOX was not critical for leaf metabolism, regardless of growth irradiance. However, under drought, the AOX amount became an important determinant of RL, which in turn was an important determinant of chloroplast energy balance (measured as photosystem II excitation pressure, EP), and photosynthetic performance. In the WT, the AOX amount increased and the LHCB2 amount decreased with increased growth irradiance or drought severity. These changes in protein amounts correlated strongly, in opposing ways, with growth EP. This suggests that a signal deriving from the photosynthetic electron transport chain status coordinately controls the amounts of AOX and LHCB2, which then both contribute to maintaining chloroplast energy balance, particularly under stress conditions. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  13. Coordinated regulation of photosynthetic and respiratory components is necessary to maintain chloroplast energy balance in varied growth conditions

    PubMed Central

    Dahal, Keshav; Martyn, Greg D.; Alber, Nicole A.

    2017-01-01

    Abstract Mitochondria have a non-energy-conserving alternative oxidase (AOX) proposed to support photosynthesis, perhaps by promoting energy balance under varying growth conditions. To investigate this, wild-type (WT) Nicotiana tabacum were compared with AOX knockdown and overexpression lines. In addition, the amount of AOX protein in WT plants was compared with that of chloroplast light-harvesting complex II (LHCB2), whose amount is known to respond to chloroplast energy status. With increased growth irradiance, WT leaves maintained higher rates of respiration in the light (RL), but no differences in RL or photosynthesis were seen between the WT and transgenic lines, suggesting that, under non-stress conditions, AOX was not critical for leaf metabolism, regardless of growth irradiance. However, under drought, the AOX amount became an important determinant of RL, which in turn was an important determinant of chloroplast energy balance (measured as photosystem II excitation pressure, EP), and photosynthetic performance. In the WT, the AOX amount increased and the LHCB2 amount decreased with increased growth irradiance or drought severity. These changes in protein amounts correlated strongly, in opposing ways, with growth EP. This suggests that a signal deriving from the photosynthetic electron transport chain status coordinately controls the amounts of AOX and LHCB2, which then both contribute to maintaining chloroplast energy balance, particularly under stress conditions. PMID:28011719

  14. Measuring and assessing maintainability at the end of high level design

    NASA Technical Reports Server (NTRS)

    Briand, Lionel C.; Morasca, Sandro; Basili, Victor R.

    1993-01-01

    Software architecture appears to be one of the main factors affecting software maintainability. Therefore, in order to be able to predict and assess maintainability early in the development process we need to be able to measure the high-level design characteristics that affect the change process. To this end, we propose a measurement approach, which is based on precise assumptions derived from the change process, which is based on Object-Oriented Design principles and is partially language independent. We define metrics for cohesion, coupling, and visibility in order to capture the difficulty of isolating, understanding, designing and validating changes.

  15. The response of serum growth hormone and prolactin to training in weight-maintaining healthy males.

    PubMed

    Hurley, R S; Bossetti, B M; O'Dorisio, T M; Welch, M A; Rice, R R; Tenison, E B; Wasson, C J; Malarkey, W B

    1990-03-01

    Resting levels of serum growth hormone (GH) and prolactin (PRL) were measured pretraining, 3 weeks and 10 weeks posttraining in seven college age males. The exercise consisted of thrice weekly sessions at 70% VO2max for 20 minutes plus warmup and cool down. Body weight remained constant during the ten week training period. However, body fat decreased significantly. Resting daytime levels of GH decreased significantly with training while resting PRL levels were unchanged. The hormone responses suggest attenuation of resting GH levels with training and may relate to changes in body fat.

  16. Maintained larval growth in mussel larvae exposed to acidified under-saturated seawater

    NASA Astrophysics Data System (ADS)

    Ventura, Alexander; Schulz, Sabrina; Dupont, Sam

    2016-03-01

    Ocean acidification (OA) is known to affect bivalve early life-stages. We tested responses of blue mussel larvae to a wide range of pH in order to identify their tolerance threshold. Our results confirmed that decreasing seawater pH and decreasing saturation state increases larval mortality rate and the percentage of abnormally developing larvae. Virtually no larvae reared at average pHT 7.16 were able to feed or reach the D-shell stage and their development appeared to be arrested at the trochophore stage. However larvae were capable of reaching the D-shell stage under milder acidification (pHT ≈ 7.35, 7.6, 7.85) including in under-saturated seawater with Ωa as low as 0.54 ± 0.01 (mean ± s. e. m.), with a tipping point for normal development identified at pHT 7.765. Additionally growth rate of normally developing larvae was not affected by lower pHT despite potential increased energy costs associated with compensatory calcification in response to increased shell dissolution. Overall, our results on OA impacts on mussel larvae suggest an average pHT of 7.16 is beyond their physiological tolerance threshold and indicate a shift in energy allocation towards growth in some individuals revealing potential OA resilience.

  17. Maintained larval growth in mussel larvae exposed to acidified under-saturated seawater

    PubMed Central

    Ventura, Alexander; Schulz, Sabrina; Dupont, Sam

    2016-01-01

    Ocean acidification (OA) is known to affect bivalve early life-stages. We tested responses of blue mussel larvae to a wide range of pH in order to identify their tolerance threshold. Our results confirmed that decreasing seawater pH and decreasing saturation state increases larval mortality rate and the percentage of abnormally developing larvae. Virtually no larvae reared at average pHT 7.16 were able to feed or reach the D-shell stage and their development appeared to be arrested at the trochophore stage. However larvae were capable of reaching the D-shell stage under milder acidification (pHT ≈ 7.35, 7.6, 7.85) including in under-saturated seawater with Ωa as low as 0.54 ± 0.01 (mean ± s. e. m.), with a tipping point for normal development identified at pHT 7.765. Additionally growth rate of normally developing larvae was not affected by lower pHT despite potential increased energy costs associated with compensatory calcification in response to increased shell dissolution. Overall, our results on OA impacts on mussel larvae suggest an average pHT of 7.16 is beyond their physiological tolerance threshold and indicate a shift in energy allocation towards growth in some individuals revealing potential OA resilience. PMID:27020613

  18. Maintained larval growth in mussel larvae exposed to acidified under-saturated seawater.

    PubMed

    Ventura, Alexander; Schulz, Sabrina; Dupont, Sam

    2016-03-29

    Ocean acidification (OA) is known to affect bivalve early life-stages. We tested responses of blue mussel larvae to a wide range of pH in order to identify their tolerance threshold. Our results confirmed that decreasing seawater pH and decreasing saturation state increases larval mortality rate and the percentage of abnormally developing larvae. Virtually no larvae reared at average pHT 7.16 were able to feed or reach the D-shell stage and their development appeared to be arrested at the trochophore stage. However larvae were capable of reaching the D-shell stage under milder acidification (pHT ≈ 7.35, 7.6, 7.85) including in under-saturated seawater with Ωa as low as 0.54 ± 0.01 (mean ± s. e. m.), with a tipping point for normal development identified at pHT 7.765. Additionally growth rate of normally developing larvae was not affected by lower pHT despite potential increased energy costs associated with compensatory calcification in response to increased shell dissolution. Overall, our results on OA impacts on mussel larvae suggest an average pHT of 7.16 is beyond their physiological tolerance threshold and indicate a shift in energy allocation towards growth in some individuals revealing potential OA resilience.

  19. Arabidopsis ACT11 modifies actin turnover to promote pollen germination and maintain the normal rate of tube growth.

    PubMed

    Chang, Ming; Huang, Shanjin

    2015-08-01

    Actin is an ancient conserved protein that is encoded by multiple isovariants in multicellular organisms. There are eight functional actin genes in the Arabidopsis genome, and the precise function and mechanism of action of each isovariant remain poorly understood. Here, we report the characterization of ACT11, a reproductive actin isovariant. Our studies reveal that loss of function of ACT11 causes a delay in pollen germination, but enhances pollen tube growth. Cytological analysis revealed that the amount of filamentous actin decreased, and the rate of actin turnover increased in act11 pollen. Convergence of actin filaments upon the germination aperture was impaired in act11 pollen, consistent with the observed delay of germination. Reduction of actin dynamics with jasplakinolide suppressed the germination and tube growth phenotypes in act11 pollen, suggesting that the underlying mechanisms involve an increase in actin dynamics. Thus, we demonstrate that ACT11 is required to maintain the rate of actin turnover in order to promote pollen germination and maintain the normal rate of pollen tube growth.

  20. Polarization maintaining fiber based ultra-high resolution spectral domain polarization sensitive optical coherence tomography

    PubMed Central

    2010-01-01

    We present a new ultra high resolution spectral domain polarization sensitive optical coherence tomography (PS-OCT) system based on polarization maintaining (PM) fibers. The method transfers the principles of our previous bulk optic PS-OCT systems to a fiberized setup. The phase shift between the orthogonal polarization states travelling in the two orthogonal modes of the PM fiber is compensated by software in post processing. Thereby, the main advantage of our bulk optics setups, i.e. the use of only a single input polarization state to simultaneously acquire reflectivity, retardation, optic axis orientation, and Stokes vector, is maintained. The use of a broadband light source of 110 nm bandwidth provides improved depth resolution and smaller speckle size. The latter is important for improved resolution of depolarization imaging. We demonstrate our instrument for high-resolution PS-OCT imaging of the healthy human retina. PMID:20052196

  1. Maintaining Participation and Momentum in Longitudinal Research Involving High-Risk Families

    PubMed Central

    Graziotti, Ann L.; Hammond, Jane; Messinger, Daniel S.; Bann, Carla M.; Miller-Loncar, Cynthia; Twomey, Jean E.; Bursi, Charlotte; Woldt, Eunice; Nelson, Jay Ann; Fleischmann, Debra; Alexander, Barbara

    2012-01-01

    Purpose The purpose of the current study was to identify and describe strategies available to optimize retention of a high-risk research cohort and assist in the recovery of study participants following participant dropout. Design and Methods The Maternal Lifestyle Study (MLS), which investigated the effects of prenatal substance exposure (cocaine or opiates) on child outcome, is a prospective longitudinal follow-up study that extended from birth through 15 years of age. Retention strategies to maximize participation and factors that might negatively impact compliance were examined over the course of five follow-up phases. Findings At the conclusion of the 15-year visits, MLS had successfully maintained compliance at 76%. Retention rates did not differ by exposure group. Conclusions Maintaining ongoing participation of enrolled study subjects is a critical element of any successful longitudinal study. Strategies that can be used to reengage and maintain participants in longitudinal research include persistence, flexibility with scheduling, home visits, long-distance trips, increased incentives, and development of a computerized tracking system. Establishing rapport with families and ensuring confidentiality contributed to overall participant retention. The use of multiple tracking techniques is essential. Clinical Relevance Researchers are challenged to maintain participants in longitudinal studies to ensure the integrity of their research. PMID:22458928

  2. Maintaining a regular physical activity aggravates intramuscular tumor growth in an orthotopic liposarcoma model.

    PubMed

    Assi, Mohamad; Derbré, Frédéric; Lefeuvre-Orfila, Luz; Saligaut, Dany; Stock, Nathalie; Ropars, Mickael; Rébillard, Amélie

    2017-01-01

    Today, care teams within cancer centers encourage patients to be physically active, after diagnosis, based on data obtained mainly from breast, colon and prostate cancer. Intriguingly, the impact of physical activity (PA) on intramuscular tumors (e.g. sarcomas) has not been specifically addressed and, thus, could be mistakenly confounded with other cancers. In this preclinical study we assessed the impact of PA on intramuscular liposarcoma (LS) evolution. Four-week-old nude male mice were active by voluntary running on wheels, for six weeks. Then, mice were divided into four groups with open or restricted access to wheels, which have received an orthotopic intramuscular injection of either vehicle or human LS, SW872, cells. Active mice presented ~1.5 fold increase in tumor mass, which was mainly due to higher cellular mitosis and proliferation. This bulging intramuscular tumor mass altered muscle function, as evidence by overall muscle strength and maximum running capacity. From a molecular point of view, active mice exhibited poor levels of Phospho-p38(Thr180/Tyr182) and p21 content in tumors and also displayed low amounts of circulating insulin comparing to inactive counterparts. Insulin induced Phospho-p38(Thr180/Tyr182) and p21 expression in SW872 cells, in vitro. The expression of p21 was regulated in a p38-dependent fashion, since inhibition of p38 activity abolished the up-regulation of p21. Our data suggest that insulin-dependent activation of p38 MAPK-p21 pathway is a possible mechanism responsible for delaying tumor growth in inactive mice. Clinically, patients with lower-extremities LS could be advised to reduce or minimize their levels of PA during the preoperative period.

  3. Maintaining a regular physical activity aggravates intramuscular tumor growth in an orthotopic liposarcoma model

    PubMed Central

    Assi, Mohamad; Derbré, Frédéric; Lefeuvre-Orfila, Luz; Saligaut, Dany; Stock, Nathalie; Ropars, Mickael; Rébillard, Amélie

    2017-01-01

    Today, care teams within cancer centers encourage patients to be physically active, after diagnosis, based on data obtained mainly from breast, colon and prostate cancer. Intriguingly, the impact of physical activity (PA) on intramuscular tumors (e.g. sarcomas) has not been specifically addressed and, thus, could be mistakenly confounded with other cancers. In this preclinical study we assessed the impact of PA on intramuscular liposarcoma (LS) evolution. Four-week-old nude male mice were active by voluntary running on wheels, for six weeks. Then, mice were divided into four groups with open or restricted access to wheels, which have received an orthotopic intramuscular injection of either vehicle or human LS, SW872, cells. Active mice presented ~1.5 fold increase in tumor mass, which was mainly due to higher cellular mitosis and proliferation. This bulging intramuscular tumor mass altered muscle function, as evidence by overall muscle strength and maximum running capacity. From a molecular point of view, active mice exhibited poor levels of Phospho-p38Thr180/Tyr182 and p21 content in tumors and also displayed low amounts of circulating insulin comparing to inactive counterparts. Insulin induced Phospho-p38Thr180/Tyr182 and p21 expression in SW872 cells, in vitro. The expression of p21 was regulated in a p38-dependent fashion, since inhibition of p38 activity abolished the up-regulation of p21. Our data suggest that insulin-dependent activation of p38 MAPK-p21 pathway is a possible mechanism responsible for delaying tumor growth in inactive mice. Clinically, patients with lower-extremities LS could be advised to reduce or minimize their levels of PA during the preoperative period. PMID:28560056

  4. Hormonal growth-promotant effects on grain-fed cattle maintained under different environments

    NASA Astrophysics Data System (ADS)

    Gaughan, J. B.; Kreikemeier, W. M.; Mader, T. L.

    2005-07-01

    Six steers (3/4 Charolais×1/4 Brahman) (mean body weight 314±27 kg) and six spayed heifers (3/5 Shorthorn×2/5 Red Angus) (mean body weight 478±30 kg) were used to determine the effects of climatic conditions and hormone growth promotants (HGP) on respiration rate (RR; breaths/min), pulse rate (beats/min), rectal temperature (RT; °C), and heat production (HP; kJ). Cattle were exposed to the following climatic conditions prior to implantation with a HGP and then again 12 days after implantation: 2 days of thermoneutral conditions (TNL) [21.9±0.9°C ambient temperature (TA) and 61.7±22.1% relative humidity (RH)] then 2 days of hot conditions [HOT; 29.2±4°C (TA) and 78.3±13.2% (RH)], then TNL for 3 days and then 2 days of cold conditions [COLD; 17.6±0.9°C (TA) and 63.4±1.8% (RH); cattle were wet during this treatment]. The HGP implants used were: estrogenic implant (E), trenbolone acetate implant (TBA), or both (ET). Both prior to and following administration of HGP, RRs were lower (P<0.05) on cold days and greater (P<0.05) on hot days compared to TNL. On hot days, RTs, were 0.62°C higher after compared to before implanting. Across all conditions, RTs were >0.5°C greater (P<0.05) for E cattle than for TBA or ET cattle. On cold days, RTs of steers were >0.8°C higher than for the heifers, while under TNL and HOT, RTs of steers were 0.2 0.35°C higher than those of heifers. Prior to implantation, HP per hour and per unit of metabolic body weight was higher (P<0.05) for cattle exposed to hot conditions, when compared to HP on cold days. After implantation, HP was greater (P<0.05) on hot days than on cold days. Under TNL, ET cattle had the lowest HP and greatest feed intake. On hot days, E cattle had the lowest HP, and the highest RT; therefore, if the potential exists for cattle death from heat episodes, the use of either TBA or ET may be preferred. Under cold conditions HP was similar among implant groups.

  5. Effect of a High-Fructose Weight-Maintaining Diet on Lipogenesis and Liver Fat.

    PubMed

    Schwarz, Jean-Marc; Noworolski, Susan M; Wen, Michael J; Dyachenko, Artem; Prior, Jessica L; Weinberg, Melissa E; Herraiz, Laurie A; Tai, Viva W; Bergeron, Nathalie; Bersot, Thomas P; Rao, Madhu N; Schambelan, Morris; Mulligan, Kathleen

    2015-06-01

    Consumption of high-fructose diets promotes hepatic fatty acid synthesis (de novo lipogenesis [DNL]) and an atherogenic lipid profile. It is unclear whether these effects occur independent of positive energy balance and weight gain. We compared the effects of a high-fructose, (25% of energy content) weight-maintaining diet to those of an isocaloric diet with the same macronutrient distribution but in which complex carbohydrate (CCHO) was substituted for fructose. Eight healthy men were studied as inpatients for consecutive 9-day periods. Stable isotope tracers were used to measure fractional hepatic DNL and endogenous glucose production (EGP) and its suppression during a euglycemic-hyperinsulinemic clamp. Liver fat was measured by magnetic resonance spectroscopy. Weight remained stable. Regardless of the order in which the diets were fed, the high-fructose diet was associated with both higher DNL (average, 18.6 ± 1.4% vs 11.0 ± 1.4% for CCHO; P = .001) and higher liver fat (median, +137% of CCHO; P = .016) in all participants. Fasting EGP and insulin-mediated glucose disposal did not differ significantly, but EGP during hyperinsulinemia was greater (0.60 ± 0.07 vs 0.46 ± 0.06 mg/kg/min; P = .013) with the high-fructose diet, suggesting blunted suppression of EGP. Short-term high-fructose intake was associated with increased DNL and liver fat in healthy men fed weight-maintaining diets.

  6. A Lipid-Accumulating Alga Maintains Growth in Outdoor, Alkaliphilic Raceway Pond with Mixed Microbial Communities

    PubMed Central

    Bell, Tisza A. S.; Prithiviraj, Bharath; Wahlen, Brad D.; Fields, Matthew W.; Peyton, Brent M.

    2016-01-01

    Algal biofuels and valuable co-products are being produced in both open and closed cultivation systems. Growing algae in open pond systems may be a more economical alternative, but this approach allows environmental microorganisms to colonize the pond and potentially infect or outcompete the algal “crop.” In this study, we monitored the microbial community of an outdoor, open raceway pond inoculated with a high lipid-producing alkaliphilic alga, Chlorella vulgaris BA050. The strain C. vulgaris BA050 was previously isolated from Soap Lake, Washington, a system characterized by a high pH (∼9.8). An outdoor raceway pond (200 L) was inoculated with C. vulgaris and monitored for 10 days and then the culture was transferred to a 2,000 L raceway pond and cultivated for an additional 6 days. Community DNA samples were collected over the 16-day period in conjunction with water chemistry analyses and cell counts. Universal primers for the SSU rRNA gene sequences for Eukarya, Bacteria, and Archaea were used for barcoded pyrosequence determination. The environmental parameters that most closely correlated with C. vulgaris abundance were pH and phosphate. Community analyses indicated that the pond system remained dominated by the Chlorella population (93% of eukaryotic sequences), but was also colonized by other microorganisms. Bacterial sequence diversity increased over time while archaeal sequence diversity declined over the same time period. Using SparCC co-occurrence network analysis, a positive correlation was observed between C. vulgaris and Pseudomonas sp. throughout the experiment, which may suggest a symbiotic relationship between the two organisms. The putative relationship coupled with high pH may have contributed to the success of C. vulgaris. The characterization of the microbial community dynamics of an alkaliphilic open pond system provides significant insight into open pond systems that could be used to control photoautotrophic biomass productivity in an

  7. A lipid-accumulating alga maintains growth in outdoor, alkaliphilic raceway pond with mixed microbial communities

    DOE PAGES

    Bell, Tisza A.S.; Prithiviraj, Bharath; Wahlen, Brad D.; ...

    2016-01-07

    Algal biofuels and valuable co-products are being produced in both open and closed cultivation systems. Growing algae in open pond systems may be a more economical alternative, but this approach allows environmental microorganisms to colonize the pond and potentially infect or outcompete the algal “crop.” In this study, we monitored the microbial community of an outdoor, open raceway pond inoculated with a high lipid-producing alkaliphilic alga, Chlorella vulgaris BA050. The strain C. vulgaris BA050 was previously isolated from Soap Lake, Washington, a system characterized by a high pH (~9.8). An outdoor raceway pond (200 L) was inoculated with C. vulgarismore » and monitored for 10 days and then the culture was transferred to a 2,000 L raceway pond and cultivated for an additional 6 days. Community DNA samples were collected over the 16-day period in conjunction with water chemistry analyses and cell counts. Universal primers for the SSU rRNA gene sequences for Eukarya, Bacteria, and Archaea were used for barcoded pyrosequence determination. The environmental parameters that most closely correlated with C. vulgaris abundance were pH and phosphate. Community analyses indicated that the pond system remained dominated by the Chlorella population (93% of eukaryotic sequences), but was also colonized by other microorganisms. Bacterial sequence diversity increased over time while archaeal sequence diversity declined over the same time period. Using SparCC co-occurrence network analysis, a positive correlation was observed between C. vulgaris and Pseudomonas sp. throughout the experiment, which may suggest a symbiotic relationship between the two organisms. The putative relationship coupled with high pH may have contributed to the success of C. vulgaris. As a result, the characterization of the microbial community dynamics of an alkaliphilic open pond system provides significant insight into open pond systems that could be used to control photoautotrophic biomass

  8. A Lipid-Accumulating Alga Maintains Growth in Outdoor, Alkaliphilic Raceway Pond with Mixed Microbial Communities.

    PubMed

    Bell, Tisza A S; Prithiviraj, Bharath; Wahlen, Brad D; Fields, Matthew W; Peyton, Brent M

    2015-01-01

    Algal biofuels and valuable co-products are being produced in both open and closed cultivation systems. Growing algae in open pond systems may be a more economical alternative, but this approach allows environmental microorganisms to colonize the pond and potentially infect or outcompete the algal "crop." In this study, we monitored the microbial community of an outdoor, open raceway pond inoculated with a high lipid-producing alkaliphilic alga, Chlorella vulgaris BA050. The strain C. vulgaris BA050 was previously isolated from Soap Lake, Washington, a system characterized by a high pH (∼9.8). An outdoor raceway pond (200 L) was inoculated with C. vulgaris and monitored for 10 days and then the culture was transferred to a 2,000 L raceway pond and cultivated for an additional 6 days. Community DNA samples were collected over the 16-day period in conjunction with water chemistry analyses and cell counts. Universal primers for the SSU rRNA gene sequences for Eukarya, Bacteria, and Archaea were used for barcoded pyrosequence determination. The environmental parameters that most closely correlated with C. vulgaris abundance were pH and phosphate. Community analyses indicated that the pond system remained dominated by the Chlorella population (93% of eukaryotic sequences), but was also colonized by other microorganisms. Bacterial sequence diversity increased over time while archaeal sequence diversity declined over the same time period. Using SparCC co-occurrence network analysis, a positive correlation was observed between C. vulgaris and Pseudomonas sp. throughout the experiment, which may suggest a symbiotic relationship between the two organisms. The putative relationship coupled with high pH may have contributed to the success of C. vulgaris. The characterization of the microbial community dynamics of an alkaliphilic open pond system provides significant insight into open pond systems that could be used to control photoautotrophic biomass productivity in an open

  9. Effectiveness of suspension seats in maintaining performance following military high-speed boat transits.

    PubMed

    Myers, Stephen D; Dobbins, Trevor D; King, Stuart; Hall, Benjamin; Holmes, Sharon R; Gunston, Tom; Dyson, Rosemary

    2012-04-01

    The aim of this study was to investigate whether suspension seats (SS) fitted to rigid inflatable boats (RIB) could help maritime boarding teams maintain running performance during the high-risk posttransit phase. High-speed RIB transits have been reported to cause reductions in the running performance of boarding teams posttransit. In this experiment, two pairs of teams completed a 3-hr transit in either calm or rough seas (calm, 5 vs. 5; rough, 6 vs. 6) in an RIB fitted with either fixed (FS) or Suspension seats (SS). Exhaustive shuttle run distance was measured pre- and immediately posttransit. Transit heart rate and perceived exertion (RPE) were measured and deck and seat pan acceleration recorded; the latter were reported as impacts count and peak magnitude. Distance run was reduced for the FS teams following both transits (calm,-250 m,-20%, p < .07; rough, -398 m, -26%, p < .05), whereas it was unchanged for the SS teams. All transit heart rates and RPE indicated light exertion levels. Seat pan impacts were similarly reduced during the calm transit (FS, -42%; SS, -30%); however, during the rough transit, the SS was more than twice as effective (FS, -32%; SS, -71%). Peak impact magnitudes were reduced by the SS (calm, -38%; rough, -57%) and amplified by the FS (calm, +3%; rough, +28%). Suspension seats effectively maintained posttransit running performance by reducing magnitude of the vertical shocks imposed on the passengers. High-speed RIB transits followed immediately by high-intensity activity are intrinsic to contemporary maritime operations; suspension seats can maintain post-transit physical performance, thereby enhancing safety and operational effectiveness.

  10. A lipid-accumulating alga maintains growth in outdoor, alkaliphilic raceway pond with mixed microbial communities

    SciTech Connect

    Bell, Tisza A.S.; Prithiviraj, Bharath; Wahlen, Brad D.; Fields, Matthew W.; Peyton, Brent M.

    2016-01-07

    Algal biofuels and valuable co-products are being produced in both open and closed cultivation systems. Growing algae in open pond systems may be a more economical alternative, but this approach allows environmental microorganisms to colonize the pond and potentially infect or outcompete the algal “crop.” In this study, we monitored the microbial community of an outdoor, open raceway pond inoculated with a high lipid-producing alkaliphilic alga, Chlorella vulgaris BA050. The strain C. vulgaris BA050 was previously isolated from Soap Lake, Washington, a system characterized by a high pH (~9.8). An outdoor raceway pond (200 L) was inoculated with C. vulgaris and monitored for 10 days and then the culture was transferred to a 2,000 L raceway pond and cultivated for an additional 6 days. Community DNA samples were collected over the 16-day period in conjunction with water chemistry analyses and cell counts. Universal primers for the SSU rRNA gene sequences for Eukarya, Bacteria, and Archaea were used for barcoded pyrosequence determination. The environmental parameters that most closely correlated with C. vulgaris abundance were pH and phosphate. Community analyses indicated that the pond system remained dominated by the Chlorella population (93% of eukaryotic sequences), but was also colonized by other microorganisms. Bacterial sequence diversity increased over time while archaeal sequence diversity declined over the same time period. Using SparCC co-occurrence network analysis, a positive correlation was observed between C. vulgaris and Pseudomonas sp. throughout the experiment, which may suggest a symbiotic relationship between the two organisms. The putative relationship coupled with high pH may have contributed to the success of C. vulgaris. As a result, the characterization of the microbial community dynamics of an alkaliphilic open pond system provides significant insight into open pond systems that could be used to

  11. Maintaining K+ balance on the low-Na+, high-K+ diet

    PubMed Central

    Cornelius, Ryan J.; Wang, Bangchen; Wang-France, Jun

    2016-01-01

    A low-Na+, high-K+ diet (LNaHK) is considered a healthier alternative to the “Western” high-Na+ diet. Because the mechanism for K+ secretion involves Na+ reabsorptive exchange for secreted K+ in the distal nephron, it is not understood how K+ is eliminated with such low Na+ intake. Animals on a LNaHK diet produce an alkaline load, high urinary flows, and markedly elevated plasma ANG II and aldosterone levels to maintain their K+ balance. Recent studies have revealed a potential mechanism involving the actions of alkalosis, urinary flow, elevated ANG II, and aldosterone on two types of K+ channels, renal outer medullary K+ and large-conductance K+ channels, located in principal and intercalated cells. Here, we review these recent advances. PMID:26739887

  12. Maintaining K(+) balance on the low-Na(+), high-K(+) diet.

    PubMed

    Cornelius, Ryan J; Wang, Bangchen; Wang-France, Jun; Sansom, Steven C

    2016-04-01

    A low-Na(+), high-K(+) diet (LNaHK) is considered a healthier alternative to the "Western" high-Na(+) diet. Because the mechanism for K(+) secretion involves Na(+) reabsorptive exchange for secreted K(+) in the distal nephron, it is not understood how K(+) is eliminated with such low Na(+) intake. Animals on a LNaHK diet produce an alkaline load, high urinary flows, and markedly elevated plasma ANG II and aldosterone levels to maintain their K(+) balance. Recent studies have revealed a potential mechanism involving the actions of alkalosis, urinary flow, elevated ANG II, and aldosterone on two types of K(+) channels, renal outer medullary K(+) and large-conductance K(+) channels, located in principal and intercalated cells. Here, we review these recent advances.

  13. High Biofilm Conductivity Maintained Despite Anode Potential Changes in a Geobacter-Enriched Biofilm.

    PubMed

    Dhar, Bipro Ranjan; Ryu, Hodon; Ren, Hao; Domingo, Jorge W Santo; Chae, Junkseck; Lee, Hyung-Sool

    2016-12-20

    This study systematically assessed intracellular electron transfer (IET) and extracellular electron transfer (EET) kinetics with respect to anode potential (Eanode ) in a mixed-culture biofilm anode enriched with Geobacter spp. High biofilm conductivity (0.96-1.24 mS cm(-1) ) was maintained during Eanode changes from -0.2 to +0.2 V versus the standard hydrogen electrode (SHE), although the steady-state current density significantly decreased from 2.05 to 0.35 A m(-2) in a microbial electrochemical cell. Substantial increase of the Treponema population was observed in the biofilm anode at Eanode =+0.2 V, which reduced intracellular electron-transfer kinetics associated with the maximum specific substrate-utilization rate by a factor of ten. This result suggests that fast EET kinetics can be maintained under dynamic Eanode conditions in a highly conductive biofilm anode as a result of shift of main EET players in the biofilm anode, although Eanode changes can influence IET kinetics. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Maintaining high activity levels in sedentary adults with a reinforcement-thinning schedule.

    PubMed

    Andrade, Leonardo F; Barry, Danielle; Litt, Mark D; Petry, Nancy M

    2014-01-01

    Physical inactivity is a leading cause of mortality. Reinforcement interventions appear to be useful for increasing activity and preventing adverse consequences of sedentary lifestyles. This study evaluated a reinforcement-thinning schedule for maintaining high activity levels. Sedentary adults (N = 77) were given pedometers and encouraged to walk ≥10,000 steps per day. Initially, all participants earned rewards for each day they walked ≥10,000 steps. Subsequently, 61 participants were randomized to a monitoring-only condition or a monitoring-plus-reinforcement-thinning condition, in which frequencies of monitoring and reinforcing walking decreased over 12 weeks. The mean (± SD) percentage of participants in the monitoring-plus-reinforcement-thinning condition who met walking goals was 83% ± 24% and was 55% ± 31% for participants in the monitoring-only condition, p < .001. Thus, monitoring plus reinforcement thinning maintained high rates of walking when it was in effect; however, groups did not differ at a 24-week follow-up. Monitoring plus reinforcement thinning, nevertheless, hold potential to extend benefits of reinforcement interventions at low costs.

  15. Maintaining High Ambulatory Activity Levels of Sedentary Adults with a Reinforcement Thinning Schedule

    PubMed Central

    Andrade, Leonardo F.; Barry, Danielle; Litt, Mark D.; Petry, Nancy M.

    2016-01-01

    Physical inactivity is a leading cause of mortality. Reinforcement interventions appear useful for increasing activity and preventing adverse consequences of sedentary lifestyles. This study evaluated a reinforcement thinning schedule for maintaining high activity levels. Sedentary adults (n=77) were given pedometers and encouraged to walk ≥10,000 steps/day. Initially, all participants earned rewards for each day they walked ≥10,000 steps. Subsequently, 61 participants were randomized to a monitoring only condition or a monitoring plus reinforcement thinning condition, in which frequencies of monitoring and reinforcing walking decreased over 12 weeks. The mean ± SD percentage of participants in the monitoring plusreinforcement thinning condition who met walking goals was 83% ± 24% versus. 55% ± 31% for participants in the monitoring only condition, p < .001. Thus, this monitoring plusreinforcement thinning schedule maintained high rates of walking when it was in effect; however, groups did not differ at a 24-week follow-up. Monitoring plus reinforcement thinning schedules, nevertheless, hold potential to extend benefits of reinforcement interventions at low costs. PMID:25041789

  16. Effect of a High-Fructose Weight-Maintaining Diet on Lipogenesis and Liver Fat

    PubMed Central

    Noworolski, Susan M.; Wen, Michael J.; Dyachenko, Artem; Prior, Jessica L.; Weinberg, Melissa E.; Herraiz, Laurie A.; Tai, Viva W.; Bergeron, Nathalie; Bersot, Thomas P.; Rao, Madhu N.; Schambelan, Morris; Mulligan, Kathleen

    2015-01-01

    Context: Consumption of high-fructose diets promotes hepatic fatty acid synthesis (de novo lipogenesis [DNL]) and an atherogenic lipid profile. It is unclear whether these effects occur independent of positive energy balance and weight gain. Objectives: We compared the effects of a high-fructose, (25% of energy content) weight-maintaining diet to those of an isocaloric diet with the same macronutrient distribution but in which complex carbohydrate (CCHO) was substituted for fructose. Design, Setting, and Participants: Eight healthy men were studied as inpatients for consecutive 9-day periods. Stable isotope tracers were used to measure fractional hepatic DNL and endogenous glucose production (EGP) and its suppression during a euglycemic-hyperinsulinemic clamp. Liver fat was measured by magnetic resonance spectroscopy. Results: Weight remained stable. Regardless of the order in which the diets were fed, the high-fructose diet was associated with both higher DNL (average, 18.6 ± 1.4% vs 11.0 ± 1.4% for CCHO; P = .001) and higher liver fat (median, +137% of CCHO; P = .016) in all participants. Fasting EGP and insulin-mediated glucose disposal did not differ significantly, but EGP during hyperinsulinemia was greater (0.60 ± 0.07 vs 0.46 ± 0.06 mg/kg/min; P = .013) with the high-fructose diet, suggesting blunted suppression of EGP. Conclusion: Short-term high-fructose intake was associated with increased DNL and liver fat in healthy men fed weight-maintaining diets. PMID:25825943

  17. Arabidopsis thaliana ggt1 photorespiratory mutants maintain leaf carbon/nitrogen balance by reducing RuBisCO content and plant growth.

    PubMed

    Dellero, Younès; Lamothe-Sibold, Marlène; Jossier, Mathieu; Hodges, Michael

    2015-09-01

    Metabolic and physiological analyses of glutamate:glyoxylate aminotransferase 1 (GGT1) mutants were performed at the global leaf scale to elucidate the mechanisms involved in their photorespiratory growth phenotype. Air-grown ggt1 mutants showed retarded growth and development, that was not observed at high CO2 (3000 μL L(-1) ). When compared to wild-type (WT) plants, air-grown ggt1 plants exhibited glyoxylate accumulation, global changes in amino acid amounts including a decrease in serine content, lower organic acid levels, and modified ATP/ADP and NADP(+) /NADPH ratios. When compared to WT plants, their net CO2 assimilation rates (An ) were 50% lower and this mirrored decreases in ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) contents. High CO2 -grown ggt1 plants transferred to air revealed a rapid decrease of An and photosynthetic electron transfer rate while maintaining a high energetic state. Short-term (a night period and 4 h of light) transferred ggt1 leaves accumulated glyoxylate and exhibited low serine contents, while other amino acid levels were not modified. RuBisCO content, activity and activation state were not altered after a short-term transfer while the ATP/ADP ratio was lowered in ggt1 rosettes. However, plant growth and RuBisCO levels were both reduced in ggt1 leaves after a long-term (12 days) acclimation to air from high CO2 when compared to WT plants. The data are discussed with respect to a reduced photorespiratory carbon recycling in the mutants. It is proposed that the low An limits nitrogen-assimilation, this decreases leaf RuBisCO content until plants attain a new homeostatic state that maintains a constant C/N balance and leads to smaller, slower growing plants. © 2015 The Authors The Plant Journal © 2015 John Wiley & Sons Ltd.

  18. NERVE GROWTH FACTOR MAINTAINS POTASSIUM CONDUCTANCE AFTER NERVE INJURY IN ADULT CUTANEOUS AFFERENT DORSAL ROOT GANGLION NEURONS

    PubMed Central

    EVERILL, B.; KOCSIS, J. D.

    2008-01-01

    Whole-cell patch-clamp techniques were used to study the effects of nerve growth factor on voltage-dependent potassium conductance in normal and axotomized identified large cutaneous afferent dorsal root ganglion neurons (48–50 μm diameter) many of which probably give rise to myelinated Aβ fibers. K-currents were isolated by blocking Na- and Ca-currents with appropriate ion replacement and channel blockers. Separation of current components was achieved on the basis of response to variation in conditioning voltage. Cutaneous afferents were labeled by the retrograde marker hydroxy-stilbamide (FluoroGold) which was injected into the skin of the foot. The sciatic nerve was either ligated or crushed with fine forceps five to seven days later. Neurons were dissociated 14–17 days after injury. The cut ends of the sciatic nerves were positioned into polyethylene tubes, which were connected to mini-osmotic pumps filled with either nerve growth factor or sterile saline. Control neurons displayed a prominent sustained K-current and the transient potassium currents “A” and “D”. Nerve ligation, which blocks target reconnection resulted in near 50% reduction of total outward current; isolated sustained K-current and transient A-current were reduced by a comparable amount. Nerve crush, which allows regeneration to peripheral targets and exposure of the regenerating nerve to the distal nerve segment, resulted in a small reduction in sustained K-current but no reduction in transient A-current compared to controls. Levels of transient A-current and sustained K-current were maintained at control levels after nerve growth factor treatment. These results indicate that the large reduction in transient A-current, and in sustained K-current, observed in cutaneous afferent cell bodies after nerve ligation is prevented by application of nerve growth factor. PMID:11008179

  19. The free energy cost of reducing noise while maintaining a high sensitivity

    PubMed Central

    Sartori, Pablo; Tu, Yuhai

    2016-01-01

    Living systems need to be highly responsive, and also to keep fluctuations low. These goals are incompatible in equilibrium systems due to the Fluctuation Dissipation Theorem (FDT). Here, we show that biological sensory systems, driven far from equilibrium by free energy consumption, can reduce their intrinsic fluctuations while maintaining high responsiveness. By developing a continuum theory of the E. coli chemotaxis pathway, we demonstrate that adaptation can be understood as a non-equilibrium phase transition controlled by free energy dissipation, and it is characterized by a breaking of the FDT. We show that the maximum response at short time is enhanced by free energy dissipation. At the same time, the low frequency fluctuations and the adaptation error decrease with the free energy dissipation algebraically and exponentially, respectively. PMID:26406857

  20. Free Energy Cost of Reducing Noise while Maintaining a High Sensitivity

    NASA Astrophysics Data System (ADS)

    Sartori, Pablo; Tu, Yuhai

    2015-09-01

    Living systems need to be highly responsive, and also to keep fluctuations low. These goals are incompatible in equilibrium systems due to the fluctuation dissipation theorem (FDT). Here, we show that biological sensory systems, driven far from equilibrium by free energy consumption, can reduce their intrinsic fluctuations while maintaining high responsiveness. By developing a continuum theory of the E. coli chemotaxis pathway, we demonstrate that adaptation can be understood as a nonequilibrium phase transition controlled by free energy dissipation, and it is characterized by a breaking of the FDT. We show that the maximum response at short time is enhanced by free energy dissipation. At the same time, the low frequency fluctuations and the adaptation error decrease with the free energy dissipation algebraically and exponentially, respectively.

  1. Atrial-specific granules in situ have high calcium content, are acidic, and maintain anion gradients.

    PubMed Central

    Somlyo, A V; Broderick, R; Shuman, H; Buhle, E L; Somlyo, A P

    1988-01-01

    The composition and pH of atrial-specific granules of rat heart were determined by electron probe x-ray microanalysis and fluorescence microscopy, respectively. The high (75 mmol/kg of dry weight) calcium content and higher than cytoplasmic concentration of chloride in atrial-specific granules were visualized in high-resolution x-ray maps. The Cl- content of granules and cytoplasm decreased and a bromide gradient (granule greater than cytoplasm) was established during incubation in low-chloride, NaBr-containing solutions. Scanning confocal fluorescence light microscopy of live atria incubated with acridine orange demonstrated dye accumulation, indicative of low intragranular pH. We conclude that the granules represent a hitherto unrecognized intracellular store of cardiac calcium and can develop and maintain an anion gradient, presumably through cotransport by means of a proton-pumping ATPase. Images PMID:3413091

  2. Plants in a crowded stand regulate their height growth so as to maintain similar heights to neighbours even when they have potential advantages in height growth

    PubMed Central

    Nagashima, Hisae; Hikosaka, Kouki

    2011-01-01

    regulate their height growth to maintain similar height to neighbours even when they have potential advantages in height growth. This might contribute to avoidance of stresses caused by wind blowing. PMID:21562027

  3. High density protein crystal growth

    NASA Technical Reports Server (NTRS)

    Rouleau, Robyn (Inventor); Delucas, Lawrence (Inventor); Hedden, Douglas Keith (Inventor)

    2004-01-01

    A protein crystal growth assembly including a crystal growth cell and further including a cell body having a top side and a bottom side and a first aperture defined therethrough, the cell body having opposing first and second sides and a second aperture defined therethrough. A cell barrel is disposed within the cell body, the cell barrel defining a cavity alignable with the first aperture of the cell body, the cell barrel being rotatable within the second aperture. A reservoir is coupled to the bottom side of the cell body and a cap having a top side is disposed on the top side of the cell body. The protein crystal growth assembly may be employed in methods including vapor diffusion crystallization, liquid to liquid crystallization, batch crystallization, and temperature induction batch mode crystallization.

  4. Spatially nonrandom tree mortality and ingrowth maintain equilibrium pattern in an old-growth Pseudotsuga-Tsuga forest.

    PubMed

    Lutz, James A; Larson, Andrew J; Furniss, Tucker J; Donato, Daniel C; Freund, James A; Swanson, Mark E; Bible, Kenneth J; Chen, Jiquan; Franklin, Jerry F

    2014-08-01

    Mortality processes in old-growth forests are generally assumed to be driven by gap-scale disturbance, with only a limited role ascribed to density-dependent mortality, but these assumptions are rarely tested with data sets incorporating repeated measurements. Using a 12-ha spatially explicit plot censused 13 years apart in an approximately 500-year-old Pseudotsuga-Tsuga forest, we demonstrate significant density-dependent mortality and spatially aggregated tree recruitment. However, the combined effect of these strongly nonrandom demographic processes was to maintain tree patterns in a state of dynamic equilibrium. Density-dependent mortality was most pronounced for the dominant late-successional species, Tsuga heterophylla. The long-lived, early-seral Pseudotsuga menziesii experienced an annual stem mortality rate of 0.84% and no new recruitment. Late-seral species Tsuga and Abies amabilis had nearly balanced demographic rates of ingrowth and mortality. The 2.34% mortality rate for Taxus brevifolia was higher than expected, notably less than ingrowth, and strongly affected by proximity to Tsuga. Large-diameter Tsuga structured both the regenerating conspecific and heterospecific cohorts with recruitment of Tsuga and Abies unlikely in neighborhoods crowded with large-diameter competitors (P < 0.001). Density-dependent competitive interactions strongly shape forest communities even five centuries after stand initiation, underscoring the dynamic nature of even equilibrial old-growth forests.

  5. High and low mammographic density human breast tissues maintain histological differential in murine tissue engineering chambers.

    PubMed

    Chew, G L; Huang, D; Lin, S J; Huo, C; Blick, T; Henderson, M A; Hill, P; Cawson, J; Morrison, W A; Campbell, I G; Hopper, J L; Southey, M C; Haviv, I; Thompson, E W

    2012-08-01

    Mammographic density (MD) is the area of breast tissue that appears radiologically white on mammography. Although high MD is a strong risk factor for breast cancer, independent of BRCA1/2 mutation status, the molecular basis of high MD and its associated breast cancer risk is poorly understood. MD studies will benefit from an animal model, where hormonal, gene and drug perturbations on MD can be measured in a preclinical context. High and low MD tissues were selectively sampled by stereotactic biopsy from operative specimens of high-risk women undergoing prophylactic mastectomy. The high and low MD tissues were transferred into separate vascularised biochambers in the groins of SCID mice. Chamber material was harvested after 6 weeks for histological analyses and immunohistochemistry for cytokeratins, vimentin and a human-specific mitochondrial antigen. Within-individual analysis was performed in replicate mice, eliminating confounding by age, body mass index and process-related factors, and comparisons were made to the parental human tissue. Maintenance of differential MD post-propagation was assessed radiographically. Immunohistochemical staining confirmed the preservation of human glandular and stromal components in the murine biochambers, with maintenance of radiographic MD differential. Propagated high MD regions had higher stromal (p = 0.0002) and lower adipose (p = 0.0006) composition, reflecting the findings in the original human breast tissue, although glands appeared small and non-complex in both high and low MD groups. No significant differences were observed in glandular area (p = 0.4) or count (p = 0.4) between high and low MD biochamber tissues. Human mammary glandular and stromal tissues were viably maintained in murine biochambers, with preservation of differential radiographic density and histological features. Our study provides a murine model for future studies into the biomolecular basis of MD as a risk factor for breast cancer.

  6. The Global Seismographic Network (GSN): Challenges and Methods for Maintaining High Quality Network Performance

    NASA Astrophysics Data System (ADS)

    Hafner, Katrin; Davis, Peter; Wilson, David; Sumy, Danielle; Woodward, Bob

    2016-04-01

    The Global Seismographic Network (GSN) is a 152 station, globally-distributed, permanent network of state-of-the-art seismological and geophysical sensors. The GSN has been operating for over 20 years via an ongoing successful partnership between IRIS, the USGS, the University of California at San Diego, NSF and numerous host institutions worldwide. The central design goal of the GSN may be summarized as "to record with full fidelity and bandwidth all seismic signals above the Earth noise, accompanied by some efforts to reduce Earth noise by deployment strategies". While many of the technical design goals have been met, we continue to strive for higher data quality with a combination of new sensors and improved installation techniques designed to achieve the lowest noise possible under existing site conditions. Data from the GSN are used not only for research, but on a daily basis as part of the operational missions of the USGS NEIC, NOAA tsunami warning centers, the Comprehensive Nuclear-Test-Ban-Treaty Organization as well as other organizations. In the recent period of very tight funding budgets, the primary challenges for the GSN include maintaining these operational capabilities while simultaneously developing and replacing the primary sensors, maintaining high quality data and repairing station infrastructure. Aging of GSN equipment and station infrastructure has resulted in renewed emphasis on developing, evaluating and implementing quality control tools such as MUSTANG and DQA to maintain the high data quality from the GSN stations. These tools allow the network operators to routinely monitor and analyze waveform data to detect and track problems and develop action plans as issues are found. We will present summary data quality metrics for the GSN as obtained via these quality assurance tools. In recent years, the GSN has standardized dataloggers to the Quanterra Q330HR data acquisition system at all but three stations resulting in significantly improved

  7. A High-Throughput Biological Calorimetry Core: Steps to Startup, Run, and Maintain a Multiuser Facility.

    PubMed

    Yennawar, Neela H; Fecko, Julia A; Showalter, Scott A; Bevilacqua, Philip C

    2016-01-01

    Many labs have conventional calorimeters where denaturation and binding experiments are setup and run one at a time. While these systems are highly informative to biopolymer folding and ligand interaction, they require considerable manual intervention for cleaning and setup. As such, the throughput for such setups is limited typically to a few runs a day. With a large number of experimental parameters to explore including different buffers, macromolecule concentrations, temperatures, ligands, mutants, controls, replicates, and instrument tests, the need for high-throughput automated calorimeters is on the rise. Lower sample volume requirements and reduced user intervention time compared to the manual instruments have improved turnover of calorimetry experiments in a high-throughput format where 25 or more runs can be conducted per day. The cost and efforts to maintain high-throughput equipment typically demands that these instruments be housed in a multiuser core facility. We describe here the steps taken to successfully start and run an automated biological calorimetry facility at Pennsylvania State University. Scientists from various departments at Penn State including Chemistry, Biochemistry and Molecular Biology, Bioengineering, Biology, Food Science, and Chemical Engineering are benefiting from this core facility. Samples studied include proteins, nucleic acids, sugars, lipids, synthetic polymers, small molecules, natural products, and virus capsids. This facility has led to higher throughput of data, which has been leveraged into grant support, attracting new faculty hire and has led to some exciting publications.

  8. Dormant bacteria within Staphylococcus epidermidis biofilms have low inflammatory properties and maintain tolerance to vancomycin and penicillin after entering planktonic growth.

    PubMed

    Cerca, Filipe; França, Angela; Pérez-Cabezas, Begoña; Carvalhais, Virgínia; Ribeiro, Adília; Azeredo, Joana; Pier, Gerald; Cerca, Nuno; Vilanova, Manuel

    2014-10-01

    Staphylococcus epidermidis is the most commonly isolated aetiological agent of nosocomial infections, mainly due to its ability to establish biofilms on indwelling medical devices. Detachment of bacteria from S. epidermidis biofilms and subsequent growth in the planktonic form is a hallmark of the pathogenesis of these infections leading to dissemination. Here we showed that S. epidermidis cells collected from biofilms cultured in conditions that promote cell viability present marked changes in their physiological status upon initiating a planktonic mode of growth. When compared to cells growing in biofilms, they displayed an increased SYBR green I staining intensity, increased transcription of the rpiA gene, decreased transcription of the icaA gene, as well as higher susceptibility to vancomycin and penicillin. When bacteria collected from biofilms with high proportions of dormant cells were subsequently cultured in the planktonic mode, a large proportion of cells maintained a low SYBR green I staining intensity and increased resistance to vancomycin and penicillin, a profile typical of dormant cells. This phenotype further associated with a decreased ability of these biofilm-derived cells to induce the production of pro-inflammatory cytokines by bone marrow-derived dendritic cells in vitro. These results demonstrated that cells detached from the biofilm maintain a dormant cell-like phenotype, having a low pro-inflammatory effect and decreased susceptibility to antibiotics, suggesting these cells may contribute to the recalcitrant nature of biofilm infections. © 2014 The Authors.

  9. Dormant bacteria within Staphylococcus epidermidis biofilms have low inflammatory properties and maintain tolerance to vancomycin and penicillin after entering planktonic growth

    PubMed Central

    Cerca, Filipe; França, Ângela; Pérez-Cabezas, Begoña; Carvalhais, Virgínia; Ribeiro, Adília; Azeredo, Joana; Pier, Gerald; Cerca, Nuno

    2014-01-01

    Staphylococcus epidermidis is the most commonly isolated aetiological agent of nosocomial infections, mainly due to its ability to establish biofilms on indwelling medical devices. Detachment of bacteria from S. epidermidis biofilms and subsequent growth in the planktonic form is a hallmark of the pathogenesis of these infections leading to dissemination. Here we showed that S. epidermidis cells collected from biofilms cultured in conditions that promote cell viability present marked changes in their physiological status upon initiating a planktonic mode of growth. When compared to cells growing in biofilms, they displayed an increased SYBR green I staining intensity, increased transcription of the rpiA gene, decreased transcription of the icaA gene, as well as higher susceptibility to vancomycin and penicillin. When bacteria collected from biofilms with high proportions of dormant cells were subsequently cultured in the planktonic mode, a large proportion of cells maintained a low SYBR green I staining intensity and increased resistance to vancomycin and penicillin, a profile typical of dormant cells. This phenotype further associated with a decreased ability of these biofilm-derived cells to induce the production of pro-inflammatory cytokines by bone marrow-derived dendritic cells in vitro. These results demonstrated that cells detached from the biofilm maintain a dormant cell-like phenotype, having a low pro-inflammatory effect and decreased susceptibility to antibiotics, suggesting these cells may contribute to the recalcitrant nature of biofilm infections. PMID:25053799

  10. How to Identify High-Growth Schools

    ERIC Educational Resources Information Center

    Pfeiffer, Linda E.

    2015-01-01

    When researching school options, parents may want to look for schools with high-growth scores which, according to research, may be indicators of other characteristics such as programming, leadership, culture, and size. This quick guide offers parents tips on how to identify high-growth schools and what to ask when evaluating school options. An…

  11. How to Identify High-Growth Schools

    ERIC Educational Resources Information Center

    Pfeiffer, Linda E.

    2015-01-01

    When researching school options, parents may want to look for schools with high-growth scores which, according to research, may be indicators of other characteristics such as programming, leadership, culture, and size. This quick guide offers parents tips on how to identify high-growth schools and what to ask when evaluating school options. An…

  12. Measuring growth rate in high-throughput growth phenotyping.

    PubMed

    Blomberg, Anders

    2011-02-01

    Growth rate is an important variable and parameter in biology with a central role in evolutionary, functional genomics, and systems biology studies. In this review the pros and cons of the different technologies presently available for high-throughput measurements of growth rate are discussed. Growth rate can be measured in liquid microcultivation of individual strains, in competition between strains, as growing colonies on agar, as division of individual cells, and estimated from molecular reporters. Irrespective of methodology, statistical issues such as spatial biases and batch effects are crucial to investigate and correct for to ensure low false discovery rates. The rather low correlations between studies indicate that cross-laboratory comparison and standardization are pressing issue to assure high-quality and comparable growth-rate data. Copyright © 2010 Elsevier Ltd. All rights reserved.

  13. Does viviparity evolve in cold climate reptiles because pregnant females maintain stable (not high) body temperatures?

    PubMed

    Shine, Richard

    2004-08-01

    Viviparity (live bearing) has evolved from egg laying (oviparity) in many lineages of lizards and snakes, apparently in response to occupancy of cold climates. Explanations for this pattern have focused on the idea that behaviorally thermoregulating (sun-basking) pregnant female reptiles can maintain higher incubation temperatures for their embryos than would be available in nests under the soil surface. This is certainly true at very high elevations, where only viviparous species occur. However, comparisons of nest and lizard temperatures at sites close to the upper elevational limit for oviparous reptiles (presumably, the selective environment where the transition from oviparity to viviparity actually occurs) suggest that reproductive mode has less effect on mean incubation temperatures than on the diel distribution of those temperatures. Nests of the oviparous scincid lizard Bassiana duperreyi showed smooth diel cycles of heating and cooling. In contrast, body temperatures of the viviparous scincid Eulamprus heatwolei rose abruptly in the morning, were high and stable during daylight hours, and fell abruptly at night. Laboratory incubation experiments mimicking these patterns showed that developmental rates of eggs and phenotypic traits of hatchling B. duperreyi were sensitive to this type of thermal variance as well as to mean temperature. Hence, diel distributions as well as mean incubation temperatures may have played an important role in the selective forces for viviparity. More generally, variances as well as mean values of abiotic factors may constitute significant selective forces on life-history evolution.

  14. High salinity helps the halophyte Sesuvium portulacastrum in defense against Cd toxicity by maintaining redox balance and photosynthesis.

    PubMed

    Wali, Mariem; Gunsè, Benet; Llugany, Mercè; Corrales, Isabel; Abdelly, Chedly; Poschenrieder, Charlotte; Ghnaya, Tahar

    2016-08-01

    NaCl alleviates Cd toxicity in Sesvium portulacastrum by maintaining plant water status and redox balance, protecting chloroplasts structure and inducing some potential Cd (2+) chelators as GSH and proline. It has been demonstrated that NaCl alleviates Cd-induced growth inhibition in the halophyte Sesuvium portulacastrum. However, the processes that mediate this effect are still unclear. In this work we combined physiological, biochemical and ultrastructural studies to highlight the effects of salt on the redox balance and photosynthesis in Cd-stressed plants. Seedlings were exposed to different Cd concentrations (0, 25 and 50 µM Cd) combined with low (0.09 mM) (LS), or high (200 mM) NaCl (HS) in hydroponic culture. Plant-water relations, photosynthesis rate, leaf gas exchange, chlorophyll fluorescence, chloroplast ultrastructure, and proline and glutathione concentrations were analyzed after 1 month of treatment. In addition, the endogenous levels of stress-related hormones were determined in plants subjected to 25 µM Cd combined with both NaCl concentrations. In plants with low salt supply (LS), Cd reduced growth, induced plant dehydration, disrupted chloroplast structure and functioning, decreased net CO2 assimilation rate (A) and transpiration rate (E), inhibited the maximum potential quantum efficiency (Fv/Fm) and the quantum yield efficiency (Φ PSII) of PSII, and enhanced the non-photochemical quenching (NPQ). The addition of 200 mM NaCl (HS) to the Cd-containing medium culture significantly mitigated Cd phytotoxicity. Hence, even at similar internal Cd concentrations, HS-Cd plants were less affected by Cd than LS-Cd ones. Hence, 200 mM NaCl significantly alleviates Cd-induced toxicity symptoms, growth inhibition, and photosynthesis disturbances. The cell ultrastructure was better preserved in HS-Cd plants but affected in LS-Cd plants. The HS-Cd plants showed also higher concentrations of reduced glutathione (GSH), proline and jasmonic acid (JA

  15. Alanylglutamine dipeptide and growth hormone maintain PepT1-mediated transport in oxidatively stressed Caco-2 cells.

    PubMed

    Alteheld, B; Evans, M E; Gu, L H; Ganapathy, V; Leibach, F H; Jones, D P; Ziegler, T R

    2005-01-01

    Reactive oxygen species (ROS) produced by gut mucosal cells during conditions such as inflammatory bowel disease (IBD) may impair mucosal repair and nutrient transport/absorptive function. Absorption of di- and tripeptides in the small intestine and colon is mediated by the H(+)-dependent transporter PepT1, but effects of oxidative stress on di- and tripeptide transport are unknown. We assessed whether exposure to hydrogen peroxide (H(2)O(2)) influences dipeptide transport in human colonic epithelial (Caco-2) cells. Uptake of [(14)C]glycylsarcosine (Gly-Sar) was used to evaluate PepT1-mediated dipeptide transport. Exposure to 1-5 mmol/L H(2)O(2) for 24 h caused a dose-dependent decrease in Gly-Sar transport, which was associated with decreased PepT1 transport velocity (V(max)). Treatment with alanylglutamine (Ala-Gln) or growth hormone (GH) did not alter Caco-2 Gly-Sar transport in the absence of H(2)O(2). However, both Ala-Gln and GH prevented the decrease in dipeptide transport observed with 1 mmol/L H(2)O(2) treatment. Ala-Gln, but not GH, maintained cellular glutathione and prevented the decrease in PepT1 protein expression. Thus, these agents should be further investigated as potential therapies to improve absorption of small peptides in disorders associated with oxidative injury to the gut mucosa.

  16. Genomic Imprinting of IGF2 Is Maintained in Infantile Hemangioma despite its High Level of Expression

    PubMed Central

    Yu, Ying; Wylie-Sears, Jill; Boscolo, Elisa; Mulliken, John B; Bischoff, Joyce

    2004-01-01

    Hemangioma, the most common tumor of infancy, is characterized by rapid growth and slow regression. Increased mRNA expression of insulin-like growth factor 2 (IGF2) has been detected in the proliferating phase by cDNA microarray analysis, but the underlying mechanism causing the increase remains unknown. Here, using quantitative real-time polymerase chain reaction (PCR) and immunohistochemistry, we show that IGF2 is highly expressed in both proliferating and involuting phase hemangioma, but is not detectable in other vascular lesions such as pyogenic granuloma, venous malformation, lymphatic malformation, or in normal infant skin. Loss of imprinting of the Igf2 gene has been associated with IGF2 overexpression in a variety of childhood tumors. To determine if loss of imprinting and consequent bi-allelic expression might contribute to the increased expression of IGF2, we examined the genomic imprinting status of Igf2 in 48 individual hemangiomas. We determined allele-specific Igf2 expression using reverse transcriptase–PCR combined with analysis of an Apa I–sensitive restriction fragment length polymorphism. Similar to heterozygous normal skin controls, all 15 informative hemangiomas showed uniform mono-allelic expression of Igf2. Therefore, loss of imprinting is not involved in the increased expression of IGF2 in infantile hemangioma. PMID:15706404

  17. Intact glycosaminoglycans from intervertebral disc-derived notochordal cell-conditioned media inhibit neurite growth while maintaining neuronal cell viability.

    PubMed

    Purmessur, Devina; Cornejo, Marisa C; Cho, Samuel K; Roughley, Peter J; Linhardt, Robert J; Hecht, Andrew C; Iatridis, James C

    2015-05-01

    Painful human intervertebral discs (IVDs) exhibit nerve growth deep into the IVD. Current treatments for discogenic back pain do not address the underlying mechanisms propagating pain and are often highly invasive or only offer temporary symptom relief. The notochord produces factors during development that pattern the spine and inhibit the growth of dorsal root ganglion (DRG) axons into the IVD. We hypothesize that notochordal cell (NC)-conditioned medium (NCCM) includes soluble factors capable of inhibiting neurite growth and may represent a future therapeutic target. To test if NCCM can inhibit neurite growth and determine if NC-derived glycosaminoglycans (GAGs) are necessary candidates for this inhibition. Human neuroblastoma (SH-SY5Y) cells and rat DRG cells were treated with NCCM in two-dimensional culture in vitro, and digestion and mechanistic studies determined if specific GAGs were responsible for inhibitory effects. Notochordal cell-conditioned medium was generated from porcine nucleus pulposus tissue that was cultured in Dulbecco's modified eagle's medium for 4 days. A dose study was performed using SH-SY5Y cells that were seeded in basal medium for 24 hours and neurite outgrowth and cell viability were assessed after treatment with basal media or NCCM (10% and 100%) for 48 hours. Glycosaminoglycans from NCCM were characterized using multiple digestions and liquid chromatography mass spectroscopy (LC-MS). Neurite growth was assessed on both SH-SY5Y and DRG cells after treatment with NCCM with and without GAG digestion. Notochordal cell-conditioned medium significantly inhibited the neurite outgrowth from SH-SY5Y cells compared with basal controls without dose or cytotoxic effects; % of neurite expressing cells were 39.0±2.9%, 27.3±3.6%, and 30.2±2.7% and mean neurite length was 60.3±3.5, 50.8±2.4, 53.2±3.7 μm for basal, 10% NCCM, and 100% NCCM, respectively. Digestions and LC-MS determined that chondroitin-6-sulfate was the major GAG chain in

  18. mTORC1 maintains the tumorigenicity of SSEA-4(+) high-grade osteosarcoma.

    PubMed

    Zhang, Wu; Ding, Meng-Lei; Zhang, Jia-Nian; Qiu, Jian-Ru; Shen, Yu-Hui; Ding, Xiao-Yi; Deng, Lian-Fu; Zhang, Wei-Bin; Zhu, Jiang

    2015-04-08

    Inactivation of p53 and/or Rb pathways restrains osteoblasts from cell-cycle exit and terminal differentiation, which underpins osteosarcoma formation coupled with dedifferentiation. Recently, the level of p-S6K was shown to independently predict the prognosis for osteosarcomas, while the reason behind this is not understood. Here we show that in certain high-grade osteosarcomas, immature SSEA-4(+) tumor cells represent a subset of tumor-initiating cells (TICs) whose pool size is maintained by mTORC1 activity. mTORC1 supports not only SSEA-4(+) cell self-renewal through S6K but also the regeneration of SSEA-4(+) TICs by SSEA-4(-) osteosarcoma cell dedifferentiation. Mechanistically, active mTORC1 is required to prevent a likely upregulation of the cell-cycle inhibitor p27 independently of p53 or Rb activation, which otherwise effectively drives the terminal differentiation of SSEA-4(-) osteosarcoma cells at the expense of dedifferentiation. Thus, mTORC1 is shown to critically regulate the retention of tumorigenicity versus differentiation in discrete differentiation phases in SSEA-4(+) TICs and their progeny.

  19. Extracellular vesicles from high grade glioma exchange diverse pro-oncogenic signals that maintain intratumoral heterogeneity

    PubMed Central

    Ricklefs, Franz; Mineo, Marco; Rooj, Arun K.; Nakano, Ichiro; Charest, Al; Weissleder, Ralph; Breakefield, Xandra O.; Chiocca, E. Antonio; Godlewski, Jakub; Bronisz, Agnieszka

    2016-01-01

    A lack of experimental models of tumor heterogeneity limits our knowledge of the complex subpopulation dynamics within the tumor ecosystem. In high grade gliomas (HGG), distinct hierarchical cell populations arise from different glioma stem-like cell (GSC) subpopulations. Extracellular vesicles (EV) shed by cells may serve as conduits of genetic and signaling communications, however, little is known about how HGG heterogeneity may impact EV content and activity. In this study, we performed a proteomic analysis of EV isolated from patient-derived GSC of either proneural or mesenchymal subtypes. EV signatures were heterogeneous, but reflected the molecular make-up of the GSC and consistently clustered into the two subtypes. EV-borne protein cargoes transferred between proneural and mesenchymal GSC increased pro-tumorigenic behaviors in vitro and in vivo. Clinically, analyses of HGG patient data from the TCGA database revealed that proneural tumors with mesenchymal EV signatures or mesenchymal tumors with proneural EV signatures were both associated with worse outcomes, suggesting influences by the proportion of tumor cells of varying subtypes in tumors. Collectively, our findings illuminate the heterogeneity among tumor EV and the complexity of HGG heterogeneity which these EV help maintain. PMID:27013191

  20. mTORC1 Maintains the Tumorigenicity of SSEA-4+ High-Grade Osteosarcoma

    PubMed Central

    Zhang, Wu; Ding, Meng-Lei; Zhang, Jia-Nian; Qiu, Jian-Ru; Shen, Yu-Hui; Ding, Xiao-Yi; Deng, Lian-Fu; Zhang, Wei-Bin; Zhu, Jiang

    2015-01-01

    Inactivation of p53 and/or Rb pathways restrains osteoblasts from cell-cycle exit and terminal differentiation, which underpins osteosarcoma formation coupled with dedifferentiation. Recently, the level of p-S6K was shown to independently predict the prognosis for osteosarcomas, while the reason behind this is not understood. Here we show that in certain high-grade osteosarcomas, immature SSEA-4+ tumor cells represent a subset of tumor-initiating cells (TICs) whose pool size is maintained by mTORC1 activity. mTORC1 supports not only SSEA-4+ cell self-renewal through S6K but also the regeneration of SSEA-4+ TICs by SSEA-4− osteosarcoma cell dedifferentiation. Mechanistically, active mTORC1 is required to prevent a likely upregulation of the cell-cycle inhibitor p27 independently of p53 or Rb activation, which otherwise effectively drives the terminal differentiation of SSEA-4− osteosarcoma cells at the expense of dedifferentiation. Thus, mTORC1 is shown to critically regulate the retention of tumorigenicity versus differentiation in discrete differentiation phases in SSEA-4+ TICs and their progeny. PMID:25853231

  1. Ballistic tongue projection in chameleons maintains high performance at low temperature.

    PubMed

    Anderson, Christopher V; Deban, Stephen M

    2010-03-23

    Environmental temperature impacts the physical activity and ecology of ectothermic animals through its effects on muscle contractile physiology. Sprinting, swimming, and jumping performance of ectotherms decreases by at least 33% over a 10 degrees C drop, accompanied by a similar decline in muscle power. We propose that ballistic movements that are powered by recoil of elastic tissues are less thermally dependent than movements that rely on direct muscular power. We found that an elastically powered movement, ballistic tongue projection in chameleons, maintains high performance over a 20 degrees C range. Peak velocity and power decline by only 10%-19% with a 10 degrees C drop, compared to >42% for nonelastic, muscle-powered tongue retraction. These results indicate that the elastic recoil mechanism circumvents the constraints that low temperature imposes on muscle rate properties and thereby reduces the thermal dependence of tongue projection. We propose that organisms that use elastic recoil mechanisms for ecologically important movements such as feeding and locomotion may benefit from an expanded thermal niche.

  2. High protein diet maintains glucose production during exercise-induced energy deficit: a controlled trial

    PubMed Central

    2011-01-01

    Background Inadequate energy intake induces changes in endogenous glucose production (GP) to preserve muscle mass. Whether addition provision of dietary protein modulates GP response to energy deficit is unclear. The objective was to determine whether exercise-induced energy deficit effects on glucose metabolism are mitigated by increased dietary protein. Methods Nineteen men ([mean ± SD] 23 ± 2 y, VO2peak 59 ± 5 ml·kg-1·min-1) were divided into three groups, two consuming moderate (MP; 0.9 g protein kg-1 d-1), and one high (HP; 1.8 g protein kg-1 d-1) protein diets (55% energy from carbohydrate) for 11 days. Following 4 days of energy balance (D1-4), energy expenditure was increased for 7 days (D5-12) in all groups. Energy intake was unchanged in two, creating a 1000 kcal d-1 deficit (DEF-MP, DEF-HP; n = 6, both groups), whereas energy balance was maintained in the third (BAL-MP, n = 7). Biochemical markers of substrate metabolism were measured during fasting rest on D4 and D12, as were GP and contribution of gluconeogenesis to endogenous glucose production (fgng) using 4-h primed, continuous infusions of [6,6-2H2]glucose (dilution-method) and [2-13C]glycerol (MIDA technique). Glycogen breakdown (GB) was derived from GP and fgng. Results Plasma β-hydroxybutyrate levels increased, and plasma glucose and insulin declined from D4 to D12, regardless of group. DEF-MP experienced decreased plasma GP from D4 to D12 ([mean change ± SD] 0.24 ± 0.24 mg·kg-1·min-1), due to reduced GB from D4 (1.40 ± 0.28 mg·kg-1·min-1) to D12 (1.16 ± 0.17 mg·kg-1·min-1), P < 0.05. Conversely, BAL-MP and DEF-HP sustained GP from D4 to D12 ([mean change ± SD] 0.1 ± 0.5 and 0.0 ± 0.2 mg·kg-1·min-1, respectively) by maintaining GB. Conclusion Exercise-induced energy deficit decreased GP and additional dietary protein mitigated that effect. PMID:21527019

  3. High protein diet maintains glucose production during exercise-induced energy deficit: a controlled trial.

    PubMed

    Smith, Tracey J; Schwarz, Jean-Marc; Montain, Scott J; Rood, Jennifer; Pikosky, Matthew A; Castaneda-Sceppa, Carmen; Glickman, Ellen; Young, Andrew J

    2011-04-28

    Inadequate energy intake induces changes in endogenous glucose production (GP) to preserve muscle mass. Whether addition provision of dietary protein modulates GP response to energy deficit is unclear. The objective was to determine whether exercise-induced energy deficit effects on glucose metabolism are mitigated by increased dietary protein. Nineteen men ([mean ± SD] 23 ± 2 y, VO2peak 59 ± 5 ml·kg-1·min-1) were divided into three groups, two consuming moderate (MP; 0.9 g protein kg-1 d-1), and one high (HP; 1.8 g protein kg-1 d-1) protein diets (55% energy from carbohydrate) for 11 days. Following 4 days of energy balance (D1-4), energy expenditure was increased for 7 days (D5-12) in all groups. Energy intake was unchanged in two, creating a 1000 kcal d-1 deficit (DEF-MP, DEF-HP; n = 6, both groups), whereas energy balance was maintained in the third (BAL-MP, n = 7). Biochemical markers of substrate metabolism were measured during fasting rest on D4 and D12, as were GP and contribution of gluconeogenesis to endogenous glucose production (fgng) using 4-h primed, continuous infusions of [6,6-2H2]glucose (dilution-method) and [2-13C]glycerol (MIDA technique). Glycogen breakdown (GB) was derived from GP and fgng. Plasma β-hydroxybutyrate levels increased, and plasma glucose and insulin declined from D4 to D12, regardless of group. DEF-MP experienced decreased plasma GP from D4 to D12 ([mean change ± SD] 0.24 ± 0.24 mg·kg-1·min-1), due to reduced GB from D4 (1.40 ± 0.28 mg·kg-1·min-1) to D12 (1.16 ± 0.17 mg·kg-1·min-1), P < 0.05. Conversely, BAL-MP and DEF-HP sustained GP from D4 to D12 ([mean change ± SD] 0.1 ± 0.5 and 0.0 ± 0.2 mg·kg-1·min-1, respectively) by maintaining GB. Exercise-induced energy deficit decreased GP and additional dietary protein mitigated that effect.

  4. Haematological, inflammatory, and immunological responses in elite judo athletes maintaining high training loads during Ramadan.

    PubMed

    Chaouachi, Anis; Coutts, Aaron J; Wong, Del P; Roky, Rachida; Mbazaa, Abderraouf; Amri, Mohamed; Chamari, Karim

    2009-10-01

    During Ramadan, Muslims abstain from food and fluid intake from dawn to sunset for 1 month. These behavioural changes that accompany Ramadan may impact upon Muslim athletes who continue to train intensely. The aim of the present study was to evaluate the effect of Ramadan intermittent fasting (RIF) on the haematological, inflammatory, and immunological measures in elite judo athletes maintaining their usual high training loads. Haematological markers of inflammation, hormones, and immune status were studied in 15 elite male judo athletes before, during, and after Ramadan. The RIF produced small but significant changes in inflammatory, hormonal, and immunological profiles in judo athletes. Serum C-reactive protein increased from 2.93 +/- 0.26 mg.L-1 pre-Ramadan to 4.60 +/- 0.51 mg.L-1 at the end of Ramadan. Haptoglobin and antitrypsin also significantly increased at different phases during Ramadan, whereas homocysteine and prealbumin remained relatively unchanged. Albumin decreased slightly by mid-Ramadan, then recovered. Immunoglobulin Aincreased from 1.87 +/- 0.56 g.L-1 before Ramadan to 2.49 +/- 0.75 g.L-1 at the end, and remained high 3 weeks after. There were no changes in the leucocyte cell counts throughout the study. The mean blood level of thyroid-stimulating hormone and free thyroxine increased significantly during RIF. Most of these changes were within the normal ranges. These results suggest that athletes who continue to train intensely during Ramadan are liable to experience a myriad of small fluctuations in hormones, immunoglobulins, antioxidants, and inflammatory responses.

  5. ESCRT-III-Associated Protein ALIX Mediates High-Affinity Phosphate Transporter Trafficking to Maintain Phosphate Homeostasis in Arabidopsis.

    PubMed

    Cardona-López, Ximena; Cuyas, Laura; Marín, Elena; Rajulu, Charukesi; Irigoyen, María Luisa; Gil, Erica; Puga, María Isabel; Bligny, Richard; Nussaume, Laurent; Geldner, Niko; Paz-Ares, Javier; Rubio, Vicente

    2015-09-01

    Prior to the release of their cargoes into the vacuolar lumen, sorting endosomes mature into multivesicular bodies (MVBs) through the action of ENDOSOMAL COMPLEX REQUIRED FOR TRANSPORT (ESCRT) protein complexes. MVB-mediated sorting of high-affinity phosphate transporters (PHT1) to the vacuole limits their plasma membrane levels under phosphate-sufficient conditions, a process that allows plants to maintain phosphate homeostasis. Here, we describe ALIX, a cytosolic protein that associates with MVB by interacting with ESCRT-III subunit SNF7 and mediates PHT1;1 trafficking to the vacuole in Arabidopsis thaliana. We show that the partial loss-of-function mutant alix-1 displays reduced vacuolar degradation of PHT1;1. ALIX derivatives containing the alix-1 mutation showed reduced interaction with SNF7, providing a simple molecular explanation for impaired cargo trafficking in alix-1 mutants. In fact, the alix-1 mutation also hampered vacuolar sorting of the brassinosteroid receptor BRI1. We also show that alix-1 displays altered vacuole morphogenesis, implying a new role for ALIX proteins in vacuolar biogenesis, likely acting as part of ESCRT-III complexes. In line with a presumed broad target spectrum, the alix-1 mutation is pleiotropic, leading to reduced plant growth and late flowering, with stronger alix mutations being lethal, indicating that ALIX participates in diverse processes in plants essential for their life.

  6. ESCRT-III-Associated Protein ALIX Mediates High-Affinity Phosphate Transporter Trafficking to Maintain Phosphate Homeostasis in Arabidopsis

    PubMed Central

    Cardona-López, Ximena; Cuyas, Laura; Marín, Elena; Irigoyen, María Luisa; Gil, Erica; Puga, María Isabel; Bligny, Richard; Nussaume, Laurent; Geldner, Niko; Paz-Ares, Javier

    2015-01-01

    Prior to the release of their cargoes into the vacuolar lumen, sorting endosomes mature into multivesicular bodies (MVBs) through the action of ENDOSOMAL COMPLEX REQUIRED FOR TRANSPORT (ESCRT) protein complexes. MVB-mediated sorting of high-affinity phosphate transporters (PHT1) to the vacuole limits their plasma membrane levels under phosphate-sufficient conditions, a process that allows plants to maintain phosphate homeostasis. Here, we describe ALIX, a cytosolic protein that associates with MVB by interacting with ESCRT-III subunit SNF7 and mediates PHT1;1 trafficking to the vacuole in Arabidopsis thaliana. We show that the partial loss-of-function mutant alix-1 displays reduced vacuolar degradation of PHT1;1. ALIX derivatives containing the alix-1 mutation showed reduced interaction with SNF7, providing a simple molecular explanation for impaired cargo trafficking in alix-1 mutants. In fact, the alix-1 mutation also hampered vacuolar sorting of the brassinosteroid receptor BRI1. We also show that alix-1 displays altered vacuole morphogenesis, implying a new role for ALIX proteins in vacuolar biogenesis, likely acting as part of ESCRT-III complexes. In line with a presumed broad target spectrum, the alix-1 mutation is pleiotropic, leading to reduced plant growth and late flowering, with stronger alix mutations being lethal, indicating that ALIX participates in diverse processes in plants essential for their life. PMID:26342016

  7. High-growth-factor implosions (HEP4)

    SciTech Connect

    Landen, O.L.; Keane, C.J.; Hammel, B.A.

    1996-06-01

    In inertial confinement fusion (ICF), the kinetic energy of an ablating, inward-driven, solid spherical shell is used to compressionally heat the low-density fuel inside. For a given drive, the maximum achievable compressed fuel density and temperature - and hence the maximum neutron production rate depend on the degree of shell isentropy and integrity maintained during the compression. Shell integrity will be degraded by hydrodynamic instability growth of areal density imperfections in the capsule. Surface imperfections on the shell grow as a result of the Richtmyer-Meshkov and Rayleigh-Taylor (RT) instabilities when the shell is accelerated by the ablating lower-density plasma. Perturbations at the outer capsule surface are transferred hydrodynamically to the inner surface, where deceleration of the shell by the lower-density fuel gives rise to further RT growth at the pusher-fuel interface.

  8. Reliability and Maintainability Analysis of a High Air Pressure Compressor Facility

    NASA Technical Reports Server (NTRS)

    Safie, Fayssal M.; Ring, Robert W.; Cole, Stuart K.

    2013-01-01

    This paper discusses a Reliability, Availability, and Maintainability (RAM) independent assessment conducted to support the refurbishment of the Compressor Station at the NASA Langley Research Center (LaRC). The paper discusses the methodologies used by the assessment team to derive the repair by replacement (RR) strategies to improve the reliability and availability of the Compressor Station (Ref.1). This includes a RAPTOR simulation model that was used to generate the statistical data analysis needed to derive a 15-year investment plan to support the refurbishment of the facility. To summarize, study results clearly indicate that the air compressors are well past their design life. The major failures of Compressors indicate that significant latent failure causes are present. Given the occurrence of these high-cost failures following compressor overhauls, future major failures should be anticipated if compressors are not replaced. Given the results from the RR analysis, the study team recommended a compressor replacement strategy. Based on the data analysis, the RR strategy will lead to sustainable operations through significant improvements in reliability, availability, and the probability of meeting the air demand with acceptable investment cost that should translate, in the long run, into major cost savings. For example, the probability of meeting air demand improved from 79.7 percent for the Base Case to 97.3 percent. Expressed in terms of a reduction in the probability of failing to meet demand (1 in 5 days to 1 in 37 days), the improvement is about 700 percent. Similarly, compressor replacement improved the operational availability of the facility from 97.5 percent to 99.8 percent. Expressed in terms of a reduction in system unavailability (1 in 40 to 1 in 500), the improvement is better than 1000 percent (an order of magnitude improvement). It is worthy to note that the methodologies, tools, and techniques used in the LaRC study can be used to evaluate

  9. High-density lipoprotein maintains skeletal muscle function by modulating cellular respiration in mice.

    PubMed

    Lehti, Maarit; Donelan, Elizabeth; Abplanalp, William; Al-Massadi, Omar; Habegger, Kirk M; Weber, Jon; Ress, Chandler; Mansfeld, Johannes; Somvanshi, Sonal; Trivedi, Chitrang; Keuper, Michaela; Ograjsek, Teja; Striese, Cynthia; Cucuruz, Sebastian; Pfluger, Paul T; Krishna, Radhakrishna; Gordon, Scott M; Silva, R A Gangani D; Luquet, Serge; Castel, Julien; Martinez, Sarah; D'Alessio, David; Davidson, W Sean; Hofmann, Susanna M

    2013-11-26

    Abnormal glucose metabolism is a central feature of disorders with increased rates of cardiovascular disease. Low levels of high-density lipoprotein (HDL) are a key predictor for cardiovascular disease. We used genetic mouse models with increased HDL levels (apolipoprotein A-I transgenic [apoA-I tg]) and reduced HDL levels (apoA-I-deficient [apoA-I ko]) to investigate whether HDL modulates mitochondrial bioenergetics in skeletal muscle. ApoA-I ko mice exhibited fasting hyperglycemia and impaired glucose tolerance test compared with wild-type mice. Mitochondria isolated from gastrocnemius muscle of apoA-I ko mice displayed markedly blunted ATP synthesis. Endurance capacity during exercise exhaustion test was impaired in apoA-I ko mice. HDL directly enhanced glucose oxidation by increasing glycolysis and mitochondrial respiration rate in C2C12 muscle cells. ApoA-I tg mice exhibited lower fasting glucose levels, improved glucose tolerance test, increased lactate levels, reduced fat mass, associated with protection against age-induced decline of endurance capacity compared with wild-type mice. Circulating levels of fibroblast growth factor 21, a novel biomarker for mitochondrial respiratory chain deficiencies and inhibitor of white adipose lipolysis, were significantly reduced in apoA-I tg mice. Consistent with an increase in glucose utilization of skeletal muscle, genetically increased HDL and apoA-I levels in mice prevented high-fat diet-induced impairment of glucose homeostasis. In view of impaired mitochondrial function and decreased HDL levels in type 2 diabetes mellitus, our findings indicate that HDL-raising therapies may preserve muscle mitochondrial function and address key aspects of type 2 diabetes mellitus beyond cardiovascular disease.

  10. Dynamic medium containing growth differentiation factor-9 and FSH maintains survival and promotes in vitro growth of caprine preantral follicles after long-term in vitro culture.

    PubMed

    Alves, A M C V; Chaves, R N; Rocha, R M P; Lima, L F; Andrade, P M; Lopes, C A P; Souza, C E A; Moura, A A A; Campello, C C; Báo, S N; Smitz, J; Figueiredo, J R

    2013-01-01

    The aim of the present study was to evaluate the effects of growth differentiation factor 9 (GDF-9) and FSH on the in vitro development of caprine preantral follicles cultured for 16 days. Ovarian fragments were cultured in αMEM⁺ (α-minimum essential medium, pH 7.2-7.4, 10 μg mL⁻¹ insulin, 5.5 μg mL⁻¹ transferrin, 5.0 ng mL⁻¹ selenium, 2 mM glutamine, 2 mM hypoxanthine and 1.25 mg mL⁻¹ bovine serum albumin) in the absence or presence of 200 ng mL⁻¹ GDF-9 and/or 50 ng mL⁻¹ FSH added during the first (Days 0-8) and/or second (Days 8-16) half of the culture period. Non-cultured and cultured fragments were processed for histological and ultrastructural analyses. After 16 days, all treatments using GDF-9 or FSH showed higher rates of follicular survival compared with αMEM⁺ alone. Compared with non-cultured control, sequential culture media containing GDF-9 and/or FSH significantly increased the percentage of developing follicles and follicle diameter. Moreover, a progressive increase in oocyte diameter was observed only with sequential culture medium containing GDF-9 until Day 8 followed by FSH (GDF-9/FSH) in the second half of the culture period. After 16 days of culture, ultrastructural analysis confirmed the integrity of follicles cultured in the presence of GDF-9/FSH. In conclusion, a dynamic medium containing GDF-9 and FSH (GDF-9/FSH) maintained follicular integrity and promoted activation of primordial follicles and growth during long-term in vitro culture of goat preantral follicles.

  11. Antinociceptive effects of high-dose remifentanil in male methadone-maintained patients.

    PubMed

    Hay, Justin L; White, Jason M; Bochner, Felix; Somogyi, Andrew A

    2008-10-01

    The treatment of acute pain in patients maintained on methadone is difficult due to increased pain sensitivity (hyperalgesia) and cross-tolerance to other opioids. This study aimed to investigate whether remifentanil elicits antinociception in methadone-maintained subjects in a dose-dependent manner. Eight chronic methadone-maintained subjects attended the testing session approximately 20 h after their normal methadone dose (range 50-110 mgday(-1)). Following a 20 min saline infusion, subjects were administered intravenous remifentanil in seven increasing doses ranging from 0.5 to 3.5 microgkg(-1)min(-1), each for 2 0min. Testing was performed in the last 10 min of each infusion. The testing measures included nociception, as measured by the cold pressor test, withdrawal using the subjective opiate withdrawal scale (SOWS), and subjective opioid effects using the morphine-benzedrine group scale (MBG). Results showed dose-dependent increase in cold pressor tolerance time from baseline of 15.6+/-3.5 (mean+/-SEM)s up to 77.3+/-24.7s during this dosing protocol. During the infusion typical mu-opioid receptor agonist side effects were observed, but with no withdrawal. Methadone-maintained patients demonstrate significant tolerance to remifentanil and may require opioid doses 20-30 higher than required for the treatment of acute pain in opioid-naïve patients.

  12. Establishing and Maintaining High Expectations for Deaf/Blind Students Using a Team Approach

    ERIC Educational Resources Information Center

    Mockler, Kimberly

    2014-01-01

    As a teacher of the deaf as well as the classroom teacher, Kimberly Mockler works very closely with the teacher of the visually impaired. This involves sharing ideas, resources, and lesson plans for the deaf/blind students. Their lessons and goals are very similar and overlap in several areas. A major challenge for both of them is maintaining high…

  13. Hormonal pleiotropy helps maintain queen signal honesty in a highly eusocial wasp

    USDA-ARS?s Scientific Manuscript database

    In insect societies, both queens and workers produce chemicals that reliably signal caste membership and reproductive status. The mechanisms that help to maintain the honesty of such queen and fertility signals, however, remain poorly studied. Here we test if queen signal honesty could be based on t...

  14. The Myxococcus xanthus Two-Component System CorSR Regulates Expression of a Gene Cluster Involved in Maintaining Copper Tolerance during Growth and Development

    PubMed Central

    Sánchez-Sutil, María Celestina; Pérez, Juana; Gómez-Santos, Nuria; Shimkets, Lawrence J.; Moraleda-Muñoz, Aurelio; Muñoz-Dorado, José

    2013-01-01

    Myxococcus xanthus is a soil-dwelling member of the δ–Proteobacteria that exhibits a complex developmental cycle upon starvation. Development comprises aggregation and differentiation into environmentally resistant myxospores in an environment that includes fluctuations in metal ion concentrations. While copper is essential for M. xanthus cells because several housekeeping enzymes use it as a cofactor, high copper concentrations are toxic. These opposing effects force cells to maintain a tight copper homeostasis. A plethora of paralogous genes involved in copper detoxification, all of which are differentially regulated, have been reported in M. xanthus. The use of in-frame deletion mutants and fusions with the reporter gene lacZ has allowed the identification of a two-component system, CorSR, that modulates the expression of an operon termed curA consisting of nine genes whose expression slowly increases after metal addition, reaching a plateau. Transcriptional regulation of this operon is complex because transcription can be initiated at different promoters and by different types of regulators. These genes confer copper tolerance during growth and development. Copper induces carotenoid production in a ΔcorSR mutant at lower concentrations than with the wild-type strain due to lack of expression of a gene product resembling subunit III of cbb3-type cytochrome c oxidase. This data may explain why copper induces carotenoid biosynthesis at suboptimal rather than optimal growth conditions in wild-type strains. PMID:23874560

  15. The Myxococcus xanthus two-component system CorSR regulates expression of a gene cluster involved in maintaining copper tolerance during growth and development.

    PubMed

    Sánchez-Sutil, María Celestina; Pérez, Juana; Gómez-Santos, Nuria; Shimkets, Lawrence J; Moraleda-Muñoz, Aurelio; Muñoz-Dorado, José

    2013-01-01

    Myxococcus xanthus is a soil-dwelling member of the δ-Proteobacteria that exhibits a complex developmental cycle upon starvation. Development comprises aggregation and differentiation into environmentally resistant myxospores in an environment that includes fluctuations in metal ion concentrations. While copper is essential for M. xanthus cells because several housekeeping enzymes use it as a cofactor, high copper concentrations are toxic. These opposing effects force cells to maintain a tight copper homeostasis. A plethora of paralogous genes involved in copper detoxification, all of which are differentially regulated, have been reported in M. xanthus. The use of in-frame deletion mutants and fusions with the reporter gene lacZ has allowed the identification of a two-component system, CorSR, that modulates the expression of an operon termed curA consisting of nine genes whose expression slowly increases after metal addition, reaching a plateau. Transcriptional regulation of this operon is complex because transcription can be initiated at different promoters and by different types of regulators. These genes confer copper tolerance during growth and development. Copper induces carotenoid production in a ΔcorSR mutant at lower concentrations than with the wild-type strain due to lack of expression of a gene product resembling subunit III of cbb3-type cytochrome c oxidase. This data may explain why copper induces carotenoid biosynthesis at suboptimal rather than optimal growth conditions in wild-type strains.

  16. Bloomfield High School: Diversity Spurs Growth

    ERIC Educational Resources Information Center

    Principal Leadership, 2012

    2012-01-01

    Changing the culture of a large, diverse high school from a place of teaching to a place of learning requires determination and the commitment of the entire school staff. Documented academic growth for all students and reduced achievement gaps over the last five years have demonstrated that Bloomfield (New Jersey) High School has made this…

  17. Bloomfield High School: Diversity Spurs Growth

    ERIC Educational Resources Information Center

    Principal Leadership, 2012

    2012-01-01

    Changing the culture of a large, diverse high school from a place of teaching to a place of learning requires determination and the commitment of the entire school staff. Documented academic growth for all students and reduced achievement gaps over the last five years have demonstrated that Bloomfield (New Jersey) High School has made this…

  18. [Withdrawal syndromes of newborns of pregnant drug abusers maintained under methadone or high-dose buprenorphine: 246 cases].

    PubMed

    Lejeune, C; Aubisson, S; Simmat-Durand, L; Cneude, F; Piquet, M; Gourarier, L

    2001-11-01

    Perinatal prognosis of pregnant drug abusers is better with intensive prenatal care and substitution maintenance programs. There is a large body of data in the literature on methadone (MTD), but very little on high-dose buprenorphine (HDB). The objective of this study was to compare 2 groups of pregnant women maintained on MTD or HDB for perinatal events. Prospective multicentric study; all neonates (NN) whose mothers has been maintained during pregnancy on MTD or HDB were included by 34 French perinatal centers with specialized staff for care of these pregnant drug abusers. Two hundred and forty-six pregnant women were included: 93 (38%) MTD and 153 (62%) HDB. Social and perinatal data, prenatal care and factors correlated with poor prenatal care are reported. Forty-six percent of the pregnant women had good prenatal care; 88% had peridural analgesia; mean birthweight=2838g; mean gestational age=38.7 weeks; prematurity<37 weeks=13; intra-uterine growth retardation=32%. Sixty-five percent neonates had withdrawal neonatal syndrome (WNNS) at a mean age of beginning at H40, mean highest Lipsitz score was 8.2 at H78. Half of the neonates with WNNS received treatment, mainly with morphine chlorhydrate. Neonatal mortality was 0/246. Discharge of the neonates was 60% with their father and their mother, and 32% with their mother alone; 4% were placed in foster homes by judicial decision. The only statistically significant differences between the MTD and HDB groups were: maintenance program was more frequently initiated before this pregnancy for the HDB vs MTD group (p<0.03); MTD maintenance was more often supervised by maintenance specialized centers and HDB by general practitioners (p<0.001); prematurity was 18% for MTD group vs 9% for HDB group (p<0.04); mean age of maximum Lipsitz score was H92 for MTD group vs H70 for HDB group (p<0.001). The perinatal medical and social prognosis of these 246 pregnant drug abusers and of their neonates appeared to be improved by the

  19. Hormonal pleiotropy helps maintain queen signal honesty in a highly eusocial wasp.

    PubMed

    Oliveira, Ricardo Caliari; Vollet-Neto, Ayrton; Akemi Oi, Cintia; van Zweden, Jelle S; Nascimento, Fabio; Sullivan Brent, Colin; Wenseleers, Tom

    2017-05-10

    In insect societies, both queens and workers produce chemicals that reliably signal caste membership and reproductive status. The mechanisms that help to maintain the honesty of such queen and fertility signals, however, remain poorly studied. Here we test if queen signal honesty could be based on the shared endocrine control of queen fertility and the production of specific signals. In support of this "hormonal pleiotropy" hypothesis, we find that in the common wasp, application of methoprene (a juveline hormone analogue) caused workers to acquire a queen-like cuticular hydrocarbon profile, resulting in the overproduction of known queen pheromones as well as some compounds typically linked to worker fertility. By contrast, administration of precocene-I (a JH inhibitor) had a tendency to have the opposite effect. Furthermore, a clear gonadotropic effect of JH in queens was suggested by the fact that circulating levels of JH were ca. 2 orders of magnitude higher in queens than those in workers and virgin, non-egg-laying queens, even if methoprene or precocene treatment did not affect the ovary development of workers. Overall, these results suggest that queen signal honesty in this system is maintained by queen fertility and queen signal production being under shared endocrine control.

  20. The Effects of Noncontingent Delivery of High- and Low-Preference Stimuli on Attention-Maintained Destructive Behavior.

    ERIC Educational Resources Information Center

    Fisher, Wayne W.; O'Connor, Julia T.; Kurtz, Patricia F.; DeLeon, Iser G.; Gotjen, Deidre L.

    2000-01-01

    An adolescent with severe mental retardation and cerebral palsy who displayed attention-maintained destructive behavior was exposed to noncontingent reinforcer delivery (NCR) with a high-preference or a low-preference stimulus while reinforcement for destructive behavior with attention remained in effect. NCR without extinction was effective only…

  1. The Effects of Noncontingent Delivery of High- and Low-Preference Stimuli on Attention-Maintained Destructive Behavior.

    ERIC Educational Resources Information Center

    Fisher, Wayne W.; O'Connor, Julia T.; Kurtz, Patricia F.; DeLeon, Iser G.; Gotjen, Deidre L.

    2000-01-01

    An adolescent with severe mental retardation and cerebral palsy who displayed attention-maintained destructive behavior was exposed to noncontingent reinforcer delivery (NCR) with a high-preference or a low-preference stimulus while reinforcement for destructive behavior with attention remained in effect. NCR without extinction was effective only…

  2. The effects of noncontingent delivery of high- and low-preference stimuli on attention-maintained destructive behavior.

    PubMed

    Fisher, W W; O'Connor, J T; Kurtz, P F; DeLeon, I G; Gotjen, D L

    2000-01-01

    An adolescent with severe mental retardation and cerebral palsy who displayed attention-maintained destructive behavior was exposed to noncontingent reinforcer delivery (NCR) with either a high-preference or a low-preference stimulus while reinforcement for destructive behavior with attention remained in effect (i.e., NCR without extinction). NCR without extinction was effective only when the high-preference stimulus was available, suggesting that systematic assessment of stimulus quality may enhance the effectiveness of NCR with alternative stimuli.

  3. Maintaining the Momentum of Students of Spanish from High School to College

    ERIC Educational Resources Information Center

    Pratt, Comfort

    2010-01-01

    This article is part of a large-scale project on the study of Spanish in high school that reports on an investigation of the low college enrollments in Spanish courses of students who study Spanish in high school. An online survey was administered to 631 high school students studying Spanish and 19 Spanish teachers, and the results revealed that…

  4. Developmental axon stretch stimulates neuron growth while maintaining normal electrical activity, intracellular calcium flux, and somatic morphology

    PubMed Central

    Loverde, Joseph R.; Pfister, Bryan J.

    2015-01-01

    Elongation of nerve fibers intuitively occurs throughout mammalian development, and is synchronized with expansion of the growing body. While most tissue systems enlarge through mitosis and differentiation, elongation of nerve fibers is remarkably unique. The emerging paradigm suggests that axons undergo stretch as contiguous tissues enlarge between the proximal and distal segments of spanning nerve fibers. While stretch is distinct from growth, tension is a known stimulus which regulates the growth of axons. Here, we hypothesized that the axon stretch-growth process may be a natural form of injury, whereby regenerative processes fortify elongating axons in order to prevent disconnection. Harnessing the live imaging capability of our axon stretch-growth bioreactors, we assessed neurons both during and following stretch for biomarkers associated with injury. Utilizing whole-cell patch clamp recording, we found no evidence of changes in spontaneous action potential activity or degradation of elicited action potentials during real-time axon stretch at strains of up to 18% applied over 5 min. Unlike traumatic axonal injury, functional calcium imaging of the soma revealed no shifts in free intracellular calcium during axon stretch. Finally, the cross-sectional areas of nuclei and cytoplasms were normal, with no evidence of chromatolysis following week-long stretch-growth limited to the lower of 25% strain or 3 mm total daily stretch. The neuronal growth cascade coupled to stretch was concluded to be independent of the changes in membrane potential, action potential generation, or calcium flux associated with traumatic injury. While axon stretch-growth is likely to share overlap with regenerative processes, we conclude that developmental stretch is a distinct stimulus from traumatic axon injury. PMID:26379492

  5. Gender differences in scalp hair growth rates are maintained but reduced in pattern hair loss compared to controls.

    PubMed

    Van Neste, D J J; Rushton, D H

    2016-08-01

    Hair loss is related to follicular density, programmed regrowth and hair productivity. The dissatisfaction with hair growth in patients experiencing hair loss might be due to slower linear hair growth rate (LHGR). LHGR and hair diameter was evaluated in Caucasian controls and patients with patterned hair loss employing the validated non-invasive, contrast-enhanced-phototrichogram with exogen collection. We evaluated 59,765 anagen hairs (controls 24,609, patients 35,156) and found thinner hairs grew slower than thicker hairs. LHGR in normal women was generally higher than in normal men. LHGR correlates with hair diameter (P < 0.006) and global thinning is associated with slower growth rates. Compared with hair of equal thickness in controls, subjects affected with patterned hair loss showed reduced hair growth rates, an observation found in both male and female patients. Males with pattern hair loss showed further reduction in growth rates as clinical severity worsened. However, sample size limitations prevented statistical evaluation of LHGR in severely affected females. Caucasian ethnicity. In pattern hair loss, LHGR significantly contributes to the apparent decrease in hair volume in affected areas. In early onset, LHRG might have a prognostic value in females but not in males. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  6. Abscisic acid accumulation modulates auxin transport in the root tip to enhance proton secretion for maintaining root growth under moderate water stress.

    PubMed

    Xu, Weifeng; Jia, Liguo; Shi, Weiming; Liang, Jiansheng; Zhou, Feng; Li, Qianfeng; Zhang, Jianhua

    2013-01-01

    Maintenance of root growth is essential for plant adaptation to soil drying. Here, we tested the hypothesis that auxin transport is involved in mediating ABA's modulation by activating proton secretion in the root tip to maintain root growth under moderate water stress. Rice and Arabidopsis plants were raised under a hydroponic system and subjected to moderate water stress (-0.47 MPa) with polyethylene glycol (PEG). ABA accumulation, auxin transport and plasma membrane H(+)-ATPase activity at the root tip were monitored in addition to the primary root elongation and root hair density. We found that moderate water stress increases ABA accumulation and auxin transport in the root apex. Additionally, ABA modulation is involved in the regulation of auxin transport in the root tip. The transported auxin activates the plasma membrane H(+)-ATPase to release more protons along the root tip in its adaption to moderate water stress. The proton secretion in the root tip is essential in maintaining or promoting primary root elongation and root hair development under moderate water stress. These results suggest that ABA accumulation modulates auxin transport in the root tip, which enhances proton secretion for maintaining root growth under moderate water stress.

  7. Nucleation and droplet growth at high pressure

    NASA Astrophysics Data System (ADS)

    Luijten, Carlo Cornelis Maria

    Homogeneous nucleation, the first stage of droplet formation in the absence of foreign particles, usually takes place in the presence of one or more supercritical carrier gases. The present work aimed at a systematic investigation of the effects of carrier gas pressure on nucleation and droplet growth. Using the so-called nucleation pulse method, nucleation and droplet growth can be separated in time, which facilitates quantitative study of these processes using Constant Angle Mie Scattering and light extinction. The method was implemented in a modified shock tube, using gas dynamic principles to create the pulse. In this way, nucleation and growth rates were measured as a function of temperature, pressure, and composition. Composition measurement at high pressure was achieved along two different routes. Water vapour concentrations were determined using a commercial humidity sensor, after calibration with total pressure as an independent parameter. Gas chromatography was used to determine hydrocarbon concentrations, after pressure reduction of the mixture over a thermostatic capillary tube. Using the above analysis techniques, nucleation and droplet growth experiments were performed for several vapour-gas mixtures, at pressures between 1 and 40 bar. Mixtures with a varying degree of interaction were selected, to allow for a systematic investigation of carrier gas influence. Besides these binary mixtures, the first quantitative nucleation and growth rates for- multicomponent-natural gas were obtained. Theoretical models for both nucleation and droplet growth were adapted to take into account the presence of a carrier gas, under condition of small carrier gas solubility. The main effects involved are the increase of saturated vapour density and decrease of surface tension with pressure. On the basis of our experiments, these effects were demonstrated to play important and counteracting roles in high pressure nucleation. Using Density Functional Theory, both effects

  8. Maintaining rotational equilibrium during object manipulation: linear behavior of a highly non-linear system.

    PubMed

    Gao, Fan; Latash, Mark L; Zatsiorsky, Vladimir M

    2006-03-01

    We address issues of simultaneous control of the grasping force and the total moment of forces applied to a handheld object during its manipulation. Six young healthy male subjects grasped an instrumented handle and performed its cyclic motion in the vertical direction. The handle allowed for setting different clockwise (negative) or counterclockwise torques. Three movement frequencies: 1, 1.5 and 2 Hz, and five different torques: -1/3, -1/6, 0, 1/6 and 1/3 Nm, were used. The rotational equilibrium was maintained by two means: (1) Concerted changes of the moments produced by the normal and tangential forces, specifically anti-phase changes of the moments during the tasks with zero external torque and in-phase changes during the non-zero-torque tasks, and (2) Redistribution of the normal forces among individual fingers such that the agonist fingers--the fingers that resist external torque--increased the force in phase with the acceleration, while the forces of the antagonist fingers--those that assist the external torque--especially, the fingers with the large moment arms, the index and little fingers, stayed unchanged. The observed effects agree with the principle of superposition--according to which some complex actions, for example, prehension, can be decomposed into elemental actions controlled independently--and the mechanical advantage hypothesis according to which in moment production the fingers are activated in proportion to their moment arms with respect to the axis of rotation. We would like to emphasize the linearity of the observed relations, which was not prescribed by the task mechanics and seems to be produced by specific neural control mechanisms.

  9. Frozen adipose-derived mesenchymal stem cells maintain high capability to grow and differentiate.

    PubMed

    Minonzio, Greta; Corazza, Mattia; Mariotta, Luca; Gola, Mauro; Zanzi, Michele; Gandolfi, Eugenio; De Fazio, Domenico; Soldati, Gianni

    2014-10-01

    In recent years, there has been a shift toward tissue-engineering strategies using stem cells for plastic and reconstructive surgical procedures. Therefore, it is important to develop safe and reproducible protocols for the extraction of adipose-derived stromal cells (ASCs) to allow cells to be stored in liquid nitrogen for future needs. The aspirated liposuction obtained from healthy donors were immediately processed after the suction using a protocol developed in our laboratory. The resulting stromal vascular fraction (SVF) was then characterized by the presence of adipose-derived stromal cells, at later stage frozen in liquid nitrogen. After that, cells were thawed and again characterized by adipose-derived stromal cells, cellular survival, differentiation ability and Colony Forming Unit-Fibroblast like colonies (CFU-F). Extraction and freezing of cells contained in the stromal vascular fraction demonstrate that thawed cells maintain the full capability to grow and differentiate in culture. The advent of adipose-derived stromal cells use in tissue engineering will assume a wide role in esthetic restoration in plastic surgery. It is thus important to develop clinically translatable protocols for the preparation and storage of adipose-derived stromal cells. Our results show that adipose-derived stromal cells in serum free can easily be frozen and stored in liquid nitrogen with retention of 85% of cell viability and 180,890 cell/g yield plus normal proliferative capacity and differentiation potential compared with fresh controls. These observations set the basis for adipose-derived stromal cells banking. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  10. Field-reversed configuration maintained by rotating magnetic field with high spatial harmonics.

    PubMed

    Inomoto, Michiaki; Kitano, Katsuhisa; Okada, Shigefumi

    2007-10-26

    Field-reversed configurations (FRCs) driven by rotating magnetic fields (RMFs) with spatial high harmonics have been studied in the metal flux conserver of the FRC injection experiment. The experimental results show that the fundamental RMF component is observed to penetrate the plasma column, while the high harmonics are screened at the plasma edge due to their slower or reversed rotation. This selective penetration of the RMF provides good compatibility of radial and azimuthal force balances; significant radial inward force mostly from the high-harmonic components, and sufficient azimuthal torque solely provided by the fundamental component.

  11. NMR spectroscopy of hyperpolarized ^129Xe at high fields: Maintaining spin polarization after optical pumping.

    NASA Astrophysics Data System (ADS)

    Patton, Brian; Kuzma, Nicholas N.; Lisitza, Natalia V.; Happer, William

    2003-05-01

    Spin-polarized ^129Xe has become an invaluable tool in nuclear magnetic resonance research, with applications ranging from medical imaging to high-resolution spectroscopy. High-field NMR studies using hyperpolarized xenon as a spectroscopic probe benefit from the high signal-to-noise ratios and large chemical shifts typical of optically-pumped noble gases. The experimental sensitivity is ultimately determined by the absolute polarization of the xenon in the sample, which can be substantially decreased during purification and transfer. NMR of xenon at high fields (9.4 Tesla) will be discussed, and potential mechanisms of spin relaxation during the distillation, storage(N. N. Kuzma, B. Patton, K. Raman, and W. Happer, Phys. Rev. Lett. 88), 147602 (2002)., and delivery of hyperpolarized xenon will be analyzed.

  12. Highly nonlinear polarization-maintaining photonic crystal fiber with nanoscale GaP strips.

    PubMed

    Amin, Md Nafiz; Faisal, Mohammad

    2016-12-10

    A highly birefringent silica photonic crystal fiber (PCF) is proposed with nanoscale gallium phosphide strips at the core and modified spiral cladding air hole distribution. Optical properties of the PCF are simulated using the finite element method. Significant influences of low-refractive-index slot region confinement and high-index strips confinement are observed for two different modes. This introduces a high birefringence of ∼0.58 at 1.55 μm wavelength. Moreover, a high nonlinearity coefficient of the order of ∼104  W-1  km-1 is achieved in the wavelength range from 1.4 to 1.7 μm. The proposed fiber will find promising applications in coherent optical communications and sensing applications.

  13. Development of silvicultural systems for maintaining old-growth conditions in the temperate rainforest of southeast Alaska.

    Treesearch

    Michael H. McClellan

    2004-01-01

    In the old-growth temperate rainforests of southeast Alaska, concerns over clearcutting effects on habitat, visual quality, slope stability, and biodiversity have created a demand for the use of other silvicultural systems. The forest vegetation and animal taxa of southeast Alaska appear to be well adapted to frequent, widespread, small-scale disturbance, suggesting...

  14. Robustly Single-mode Polarization Maintaining Er/Yb co-doped LMA Fiber for High Power Applications

    DTIC Science & Technology

    2007-05-08

    the fabrication of highly efficient, polarization maintaining ( PM ) LMA fibers. A PM - LMA Er/Yb co-doped fiber suitable for nanosecond pulsed...associated with fabricating LMA Er/Yb and Tm-doped fibers have previously been discussed in detail by Tankala et. al. [6]. In the case of a PM - LMA ...demonstrate a large core diameter PM Er/Yb fiber incorporating a unique raised inner-cladding which facilitates the use of conventional LMA mode selection

  15. Maintaining the Momentum from High School to College: Report and Recommendations.

    ERIC Educational Resources Information Center

    Andress, Reinhard; James, Charles J.; Jurasek, Barbara; Lalande, John F., II; Lovik, Thomas A.; Lund, Deborah; Stoyak, Daniel P.; Tatlock, Lynne; Wipf, Joseph A.

    2002-01-01

    Reports on data gathered in an AATG-sponsored national survey of U.S. high school students enrolled in upper-level German courses, investigating why students select German, continue learning German, and plan to take German in college. The results are discussed and recommendations with regard to affective motivators are made. (AS)

  16. Do High Flyers Maintain Their Altitude? Performance Trends of Top Students

    ERIC Educational Resources Information Center

    Xiang, Yun; Dahlin, Michael; Cronin, John; Theaker, Robert; Durant, Sarah

    2011-01-01

    This groundbreaking study is the first ever to examine the achievement of high-performing students over time "at the individual level". It poses--and seeks to answer--this straightforward question: Do students who outscore their peers on standardized achievement tests remain at the top of the pack year after year? Put differently, how many "high…

  17. Maintaining high precision of isotope ratio analysis over extended periods of time.

    PubMed

    Brand, Willi A

    2009-06-01

    Stable isotope ratios are reliable and long lasting process tracers. In order to compare data from different locations or different sampling times at a high level of precision, a measurement strategy must include reliable traceability to an international stable isotope scale via a reference material (RM). Since these international RMs are available in low quantities only, we have developed our own analysis schemes involving laboratory working RM. In addition, quality assurance RMs are used to control the long-term performance of the delta-value assignments. The analysis schemes allow the construction of quality assurance performance charts over years of operation. In this contribution, the performance of three typical techniques established in IsoLab at the MPI-BGC in Jena is discussed. The techniques are (1) isotope ratio mass spectrometry with an elemental analyser for delta(15)N and delta(13)C analysis of bulk (organic) material, (2) high precision delta(13)C and delta(18)O analysis of CO(2) in clean-air samples, and (3) stable isotope analysis of water samples using a high-temperature reaction with carbon. In addition, reference strategies on a laser ablation system for high spatial resolution delta(13)C analysis in tree rings is exemplified briefly.

  18. Characteristics of high quality sorbent for fluidized bed combustion and problems of maintaining uniform reactivity

    SciTech Connect

    Bain, R.J. . Dept. of Geology)

    1993-03-01

    Fluidized bed combustion of coal is considered one of the more promising clean coal technologies for the future. While much research has gone into the design and operation of FBC units, there is little concern for what characterizes a high quality sorbent and the source of such a sorbent. Carbonate rocks, limestone and dolomite, have been tested extensively as sorbents and primarily two rock characteristics appear to significantly control reactivity: composition and texture. Calcium carbonate is more reactive than magnesium carbonate where all other rock characteristics are the same. In considering texture, highest reactivity is measured for carbonate rocks which consist of homogeneous, euhedral crystals ranging in size from .05 to .2 mm and which possess uniform intercrystalline porosity. The most reactive material possesses both high calcium content, uniform microcrystalline texture and intercrystalline porosity, however, such material is not very abundant in nature and is not locally available to midcontinent facilities. Sucrosic dolomite, which possesses uniform microcrystalline texture and intercrystalline porosity has high rank reactivity. While this rock is quite common, it occurs as beds, generally less than twenty feet thick, interlayered with less reactive dolomite types. Therefore, without selective quarrying methods, production of sorbent with uniformly high reactivity will be impossible.

  19. SOLVING COPPER CORROSION PROBLEMS WHILE MAINTAINING LEAD CONTROL IN A HIGH ALKALINITY WATER USING ORTHOPHOSPHATE

    EPA Science Inventory

    Lead and Copper Rule sampling in 1992 uncovered high copper levels in many homes in the Indian Hill Water Works, Ohio (IHWW) water system. The 90th percentile copper and lead levels were 1.63 mg/L and 0.012 mg/L, respectively. IHWW supplies water to several suburban communities t...

  20. An At-Risk Small Urban High School: Maintaining Accreditation Status

    ERIC Educational Resources Information Center

    Kirchmann, Laszlo, Jr.

    2017-01-01

    The purpose of this qualitative single case study was to investigate the performance of a small, urban high school in the northeastern United States by examining graduation rates, attendance, test scores, and inappropriate student behavior to determine at what levels the school is at risk of losing accreditation. The selected school had declined…

  1. Establishing and Maintaining High-Performing Leadership Teams: A Primary Perspective

    ERIC Educational Resources Information Center

    Abbott, Ian; Bush, Tony

    2013-01-01

    This article reports on the findings from a study into high-performing leadership teams in English primary schools. The schools, in the sample, received "outstanding" Office for Standards in Education (Ofsted) grades overall, and for leadership and management, in their most recent school inspection. The evidence suggests that developing…

  2. Establishing and Maintaining High-Performing Leadership Teams: A Primary Perspective

    ERIC Educational Resources Information Center

    Abbott, Ian; Bush, Tony

    2013-01-01

    This article reports on the findings from a study into high-performing leadership teams in English primary schools. The schools, in the sample, received "outstanding" Office for Standards in Education (Ofsted) grades overall, and for leadership and management, in their most recent school inspection. The evidence suggests that developing…

  3. SOLVING COPPER CORROSION PROBLEMS WHILE MAINTAINING LEAD CONTROL IN A HIGH ALKALINITY WATER USING ORTHOPHOSPHATE

    EPA Science Inventory

    Lead and Copper Rule sampling in 1992 uncovered high copper levels in many homes in the Indian Hill Water Works, Ohio (IHWW) water system. The 90th percentile copper and lead levels were 1.63 mg/L and 0.012 mg/L, respectively. IHWW supplies water to several suburban communities t...

  4. Recombinant fetuin-B protein maintains high fertilization rate in cumulus cell-free mouse oocytes.

    PubMed

    Dietzel, E; Floehr, J; Van de Leur, E; Weiskirchen, R; Jahnen-Dechent, W

    2017-01-01

    Does fetuin-B inhibit premature zona pellucida (ZP) hardening in mouse oocytes in vitro and thus increase IVF rate? Supplementation of oocyte in vitro maturation (IVM) media with recombinant mouse fetuin-B (rmFetuB) increased fertilization rate without affecting mouse embryo development into blastocysts. Mice deficient in fetuin-B are infertile owing to premature ZP hardening. Premature ZP hardening also occurs during oocyte IVM leading to decreased fertilization rate. We fertilized batches of 20-30 mouse metaphase II (Mll) stage oocytes from C57BL/6 mice with fresh sperm, and studied early embryo development until blastocyst hatching. Oocytes were maintained with or without rmFetuB during IVM and IVF. Exogenous rmFetuB was added to media prior to oocyte isolation. ZP hardening was quantified by chymotrypsin digestion timing and by counting attached sperm. In the absence of cumulus cells, rmFetuB dose-dependently inhibited ZP hardening and increased IVF rate (P = 0.039). Fetuin-B at ≥0.03 mg/ml also inhibited physiological, fertilization-triggered ZP hardening (indicated by increased sperm binding, P = 0.0002), without increasing embryo death. Exogenous rmFetuB increased IVF rate for up to 5 hours of IVM (P = 0.02 at 1 hour, P = 0.01 at 5 hours of IVM). Mll stage oocytes in this study were isolated from the ampullae of fetuin-B expressing mice. Thus, oocytes were protected against premature ZP hardening by endogenous fetuin-B. In humans and livestock, oocytes are usually isolated by follicle puncture before ovulation. In this situation, the deprivation of endogenous fetuin-B would occur earlier and the effect of exogenous fetuin-B in the IVF medium may be even more pronounced. Fertilization-triggered ZP hardening is essential for embryo development but in this study the effect of fetuin-B supplementation was only studied to blastocyst stage. Any influence of added fetuin-B on later embryo development after transplantation remains to be determined. The astacin

  5. Acetyl-CoA Synthetase 2 Promotes Acetate Utilization and Maintains Cancer Cell Growth under Metabolic Stress

    PubMed Central

    Schug, Zachary T.; Peck, Barrie; Jones, Dylan T.; Zhang, Qifeng; Grosskurth, Shaun; Alam, Israt S.; Goodwin, Louise M.; Smethurst, Elizabeth; Mason, Susan; Blyth, Karen; McGarry, Lynn; James, Daniel; Shanks, Emma; Kalna, Gabriela; Saunders, Rebecca E.; Jiang, Ming; Howell, Michael; Lassailly, Francois; Thin, May Zaw; Spencer-Dene, Bradley; Stamp, Gordon; van den Broek, Niels J.F.; Mackay, Gillian; Bulusu, Vinay; Kamphorst, Jurre J.; Tardito, Saverio; Strachan, David; Harris, Adrian L.; Aboagye, Eric O.; Critchlow, Susan E.; Wakelam, Michael J.O.; Schulze, Almut; Gottlieb, Eyal

    2015-01-01

    Summary A functional genomics study revealed that the activity of acetyl-CoA synthetase 2 (ACSS2) contributes to cancer cell growth under low-oxygen and lipid-depleted conditions. Comparative metabolomics and lipidomics demonstrated that acetate is used as a nutritional source by cancer cells in an ACSS2-dependent manner, and supplied a significant fraction of the carbon within the fatty acid and phospholipid pools. ACSS2 expression is upregulated under metabolically stressed conditions and ACSS2 silencing reduced the growth of tumor xenografts. ACSS2 exhibits copy-number gain in human breast tumors, and ACSS2 expression correlates with disease progression. These results signify a critical role for acetate consumption in the production of lipid biomass within the harsh tumor microenvironment. PMID:25584894

  6. Growth hormone/IGF-I and/or resistive exercise maintains myonuclear number in hindlimb unweighted muscles

    NASA Technical Reports Server (NTRS)

    Allen, D. L.; Linderman, J. K.; Roy, R. R.; Grindeland, R. E.; Mukku, V.; Edgerton, V. R.

    1997-01-01

    In the present study of rats, we examined the role, during 2 wk of hindlimb suspension, of growth hormone/insulin-like growth factor I (GH/IGF-I) administration and/or brief bouts of resistance exercise in ameliorating the loss of myonuclei in fibers of the soleus muscle that express type I myosin heavy chain. Hindlimb suspension resulted in a significant decrease in mean soleus wet weight that was attenuated either by exercise alone or by exercise plus GH/IGF-I treatment but was not attenuated by hormonal treatment alone. Both mean myonuclear number and mean fiber cross-sectional area (CSA) of fibers expressing type I myosin heavy chain decreased after 2 wk of suspension compared with control (134 vs. 162 myonuclei/mm and 917 vs. 2,076 micron2, respectively). Neither GH/IGF-I treatment nor exercise alone affected myonuclear number or fiber CSA, but the combination of exercise and growth-factor treatment attenuated the decrease in both variables. A significant correlation was found between mean myonuclear number and mean CSA across all groups. Thus GH/IGF-I administration and brief bouts of muscle loading had an interactive effect in attenuating the loss of myonuclei induced by chronic unloading.

  7. Menaquinone synthesis is critical for maintaining mycobacterial viability during exponential growth and recovery from non-replicating persistence.

    PubMed

    Dhiman, Rakesh K; Mahapatra, Sebabrata; Slayden, Richard A; Boyne, Melissa E; Lenaerts, Anne; Hinshaw, Jerald C; Angala, Shiva K; Chatterjee, Delphi; Biswas, Kallolmay; Narayanasamy, Prabagaran; Kurosu, Michio; Crick, Dean C

    2009-04-01

    Understanding the basis of bacterial persistence in latent infections is critical for eradication of tuberculosis. Analysis of Mycobacterium tuberculosis mRNA expression in an in vitro model of non-replicating persistence indicated that the bacilli require electron transport chain components and ATP synthesis for survival. Additionally, low microM concentrations of aminoalkoxydiphenylmethane derivatives inhibited both the aerobic growth and survival of non-replicating, persistent M. tuberculosis. Metabolic labelling studies and quantification of cellular menaquinone levels suggested that menaquinone synthesis, and consequently electron transport, is the target of the aminoalkoxydiphenylmethane derivatives. This hypothesis is strongly supported by the observations that treatment with these compounds inhibits oxygen consumption and that supplementation of growth medium with exogenous menaquinone rescued both growth and oxygen consumption of treated bacilli. In vitro assays indicate that the aminoalkoxydiphenylmethane derivatives specifically inhibit MenA, an enzyme involved in the synthesis of menaquinone. Thus, the results provide insight into the physiology of mycobacterial persistence and a basis for the development of novel drugs that enhance eradication of persistent bacilli and latent tuberculosis.

  8. Growth hormone/IGF-I and/or resistive exercise maintains myonuclear number in hindlimb unweighted muscles

    NASA Technical Reports Server (NTRS)

    Allen, D. L.; Linderman, J. K.; Roy, R. R.; Grindeland, R. E.; Mukku, V.; Edgerton, V. R.

    1997-01-01

    In the present study of rats, we examined the role, during 2 wk of hindlimb suspension, of growth hormone/insulin-like growth factor I (GH/IGF-I) administration and/or brief bouts of resistance exercise in ameliorating the loss of myonuclei in fibers of the soleus muscle that express type I myosin heavy chain. Hindlimb suspension resulted in a significant decrease in mean soleus wet weight that was attenuated either by exercise alone or by exercise plus GH/IGF-I treatment but was not attenuated by hormonal treatment alone. Both mean myonuclear number and mean fiber cross-sectional area (CSA) of fibers expressing type I myosin heavy chain decreased after 2 wk of suspension compared with control (134 vs. 162 myonuclei/mm and 917 vs. 2,076 micron2, respectively). Neither GH/IGF-I treatment nor exercise alone affected myonuclear number or fiber CSA, but the combination of exercise and growth-factor treatment attenuated the decrease in both variables. A significant correlation was found between mean myonuclear number and mean CSA across all groups. Thus GH/IGF-I administration and brief bouts of muscle loading had an interactive effect in attenuating the loss of myonuclei induced by chronic unloading.

  9. Development of a Remotely Maintained, High Temperature Vacuum Extraction Furnace for the Tritium Extraction Facility

    SciTech Connect

    Teese, G.D.

    2001-02-06

    Future production of tritium for use in US nuclear weapons will be accomplished by irradiation of Tritium Producing Burnable Absorber Rods (TPBARs) in a pressurized water reactor (PWR). The TPBARs will be subsequently shipped to the Tritium Extraction Facility (TEF) for processing. The TPBAR outside tube and end fittings are constructed of stainless steel, and become activated during irradiation. In order to allow workers to safely process the irradiated TPBARs, remote handling is being planned for the TEF. A key step in the tritium extraction process is the removal of the tritium from the TPBARs in a high temperature, vacuum extraction process.

  10. Virgin coconut oil maintains redox status and improves glycemic conditions in high fructose fed rats.

    PubMed

    Narayanankutty, Arunaksharan; Mukesh, Reshma K; Ayoob, Shabna K; Ramavarma, Smitha K; Suseela, Indu M; Manalil, Jeksy J; Kuzhivelil, Balu T; Raghavamenon, Achuthan C

    2016-01-01

    Virgin Coconut Oil (VCO), extracted from fresh coconut kernel possess similar fatty acid composition to that of Copra Oil (CO), a product of dried kernel. Although CO forms the predominant dietary constituent in south India, VCO is being promoted for healthy life due to its constituent antioxidant molecules. High fructose containing CO is an established model for insulin resistance and steatohepatitis in rodents. In this study, replacement of CO with VCO in high fructose diet markedly improved the glucose metabolism and dyslipidemia. The animals fed VCO diet had only 17 % increase in blood glucose level compared to CO fed animals (46 %). Increased level of GSH and antioxidant enzyme activities in VCO fed rats indicate improved hepatic redox status. Reduced lipid peroxidation and carbonyl adducts in VCO fed rats well corroborate with the histopathological findings that hepatic damage and steatosis were comparatively reduced than the CO fed animals. These results suggest that VCO could be an efficient nutraceutical in preventing the development of diet induced insulin resistance and associated complications possibly through its antioxidant efficacy.

  11. Bats are able to maintain long-term social relationships despite the high fission–fusion dynamics of their groups

    PubMed Central

    Kerth, Gerald; Perony, Nicolas; Schweitzer, Frank

    2011-01-01

    Elephants, dolphins, as well as some carnivores and primates maintain social links despite their frequent splitting and merging in groups of variable composition, a phenomenon known as fission–fusion. Information on the dynamics of social links and interactions among individuals is of high importance to the understanding of the evolution of animal sociality, including that of humans. However, detailed long-term data on such dynamics in wild mammals with fully known demography and kin structures are scarce. Applying a weighted network analysis on 20 500 individual roosting observations over 5 years, we show that in two wild Bechstein's bat colonies with high fission–fusion dynamics, individuals of different age, size, reproductive status and relatedness maintain long-term social relationships. In the larger colony, we detected two stable subunits, each comprising bats from several family lineages. Links between these subunits were mainly maintained by older bats and persisted over all years. Moreover, we show that the full details of the social structure become apparent only when large datasets are used. The stable multi-level social structures in Bechstein's bat colonies resemble that of elephants, dolphins and some primates. Our findings thus may shed new light on the link between social complexity and social cognition in mammals. PMID:21307051

  12. MAINTAINING HIGH RESOLUTION MASS SPECTROMETRY CAPABILITIES FOR NATIONAL NUCLEAR SECURITY ADMINISTRATION APPLICATIONS

    SciTech Connect

    Wyrick, S.; Cordaro, J.; Reeves, G.; Mcintosh, J.; Mauldin, C.; Tietze, K.; Varble, D.

    2011-06-06

    The Department of Energy (DOE) National Nuclear Security Administration (NNSA) has a specialized need for analyzing low mass gas species at very high resolutions. The currently preferred analytical method is electromagnetic sector mass spectrometry. This method allows the NNSA Nuclear Security Enterprise (NSE) to resolve species of similar masses down to acceptable minimum detection limits (MDLs). Some examples of these similar masses are helium-4/deuterium and carbon monoxide/nitrogen. Through the 1980s and 1990s, there were two vendors who supplied and supported these instruments. However, with declining procurements and down turns in the economy, the supply of instruments, service and spare parts from these vendors has become less available, and in some cases, nonexistent. The largest NSE user of this capability is the Savannah River Site (SRS), located near Aiken, South Carolina. The Research and Development Engineering (R&DE) Group in the Savannah River National Laboratory (SRNL) investigated the areas of instrument support that were needed to extend the life cycle of these aging instruments. Their conclusions, as to the focus areas of electromagnetic sector mass spectrometers to address, in order of priority, were electronics, software and hardware. Over the past 3-5 years, the R&DE Group has designed state of the art electronics and software that will allow high resolution legacy mass spectrometers, critical to the NNSA mission, to be operated for the foreseeable future. The funding support for this effort has been from several sources, including the SRS Defense Programs, NNSA Readiness Campaign, Pantex Plant and Sandia National Laboratory. To date, electronics systems have been upgraded on one development system at SRNL, two production systems at Pantex and one production system at Sandia National Laboratory. An NSE working group meets periodically to review strategies going forward. The R&DE Group has also applied their work to the electronics for a

  13. Fatal wounds sustained from "falling bullets": maintaining a high index of suspicion in a forensic setting.

    PubMed

    Rapkiewicz, Amy V; Shuman, Mark J; Hutchins, Kenneth D

    2014-01-01

    Celebratory gunfire injuries from "falling bullets" occur when guns are fired into the air during celebrations without realizing that this can cause serious injuries or even fatalities. Fatal celebratory gunfire injury is an uncommonly reported event in the continental United States. Our electronic database was queried for homicides occurring within days of July 4th and December 31st over a 14-year period. We describe two cases of fatal gunfire injury due to celebratory gunfire occurring during New Year's Eve in Southern Florida. The relevant literature is reviewed. These case reports illustrate that fatal gunfire injuries sustained from "falling bullets" may pose as an unexpected mimic to sudden natural deaths especially in patients with prior medical history. A high index of suspicion to recognize such injury is required particularly during holidays. 2013 American Academy of Forensic Sciences Published 2013. This article is a U.S. Government work and is in the public domain in the U.S.A.

  14. Polarization maintaining highly nonlinear photonic crystal fiber with closely lying two zero dispersion wavelengths

    NASA Astrophysics Data System (ADS)

    Hasan, Md. Rabiul; Anower, Md. Shamim; Hasan, Md. Imran

    2016-05-01

    A simple hexagonal photonic crystal fiber is proposed to simultaneously achieve ultrahigh birefringence, large nonlinear coefficient, and two zero dispersion wavelengths (ZDWs). The finite element method with circular perfectly matched layer boundary condition is used to simulate the designed structure. Simulation results show that it is possible to achieve two closely lying ZDWs of 1.08 and 1.29 μm for x-polarization with 0.88 and 1.20 μm for y-polarization modes, respectively. In addition, an ultrahigh birefringence of 3.15×10-2 and a high nonlinear coefficient of 58 W-1 km-1 are also obtained at the excitation wavelength of 1.55 μm. The proposed fiber can have important applications in supercontinuum generation, parametric amplification, four-wave mixing, and optical sensors design.

  15. Brünnich's guillemots (Uria lomvia) maintain high temperature in the body core during dives.

    PubMed

    Niizuma, Yasuaki; Gabrielsen, Geir W; Sato, Katsufumi; Watanuki, Yutaka; Naito, Yasuhiko

    2007-06-01

    A major challenge for diving birds, reptiles, and mammals is regulating body temperature while conserving oxygen through a reduction in metabolic processes. To gain insight into how these needs are met, we measured dive depth and body temperatures at the core or periphery between the skin and abdominal muscles simultaneously in freely diving Brünnich's guillemots (Uria lomvia), an arctic seabird, using an implantable data logger (16-mm diameter, 50-mm length, 14-g mass, Little Leonardo Ltd., Tokyo). Guillemots exhibited increased body core temperatures, but decreased peripheral temperatures, during diving. Heat conservation within the body core appeared to result from the combined effect of peripheral vasoconstriction and a high wing beat frequency that generates heat. Conversely, the observed tissue hypothermia in the periphery should reduce metabolic processes as well as heat loss to the water. These physiological effects are likely one of the key physiological adaptations that makes guillemots to perform as an efficient predator in arctic waters.

  16. Rates of fetal polydrug exposures in methadone-maintained pregnancies from a high-risk population.

    PubMed

    Delano, Kaitlyn; Gareri, Joey; Koren, Gideon

    2013-01-01

    Methadone maintenance treatment (MMT) is the standard of care during pregnancy for opioid-dependency, showing efficacy in improving prenatal care and reducing risk of relapse. By design, however, MMT is only intended to prevent withdrawal thus facilitating cognitive behavioural interventions. In order to maximize the benefits of MMT, it is essential that methadone is both properly prescribed and that additional addiction treatment is concurrently administered. This study aims to determine the effectiveness of MMT engagement in high-risk pregnant women in reducing polydrug use by objective laboratory examination of neonatal meconium. Over a 29-month period, the Motherisk Laboratory at the Hospital for Sick Children in Toronto analyzed meconium samples as per request by social services and hospitals for drugs of abuse. Of the 904 meconium samples received, 273 were tested for methadone with 164 positive and 109 negative for methadone. Almost half of the methadone positive samples (46.34%) were also positive for at least one other opioid compound, which did not differ statistically from the methadone-negative control samples (46.79%; Chi square test, p=0.94). No differences were found between the methadone positive and negative groups in rates of concurrent amphetamines, cocaine, cannabis, and alcohol use indicating a similar risk of polydrug use between pregnant women taking or not taking methadone in this population. The high rates of additional opioid and other drug use in the MMT group, suggest that MMT is failing this population of patients. It is possible that methadone doses during pregnancy are not appropriately adjusted for changes in pharmacokinetic parameters (e.g. blood volume, renal function) during the second and third trimesters. This may result in sub-therapeutic dosing creating withdrawal symptoms leading to additional substance use. Alternatively, these results may be demonstrating a substantial lack in delivery of addiction support services in this

  17. Phosphorus recycling in photorespiration maintains high photosynthetic capacity in woody species.

    PubMed

    Ellsworth, David S; Crous, Kristine Y; Lambers, Hans; Cooke, Julia

    2015-06-01

    Leaf photosynthetic CO2 responses can provide insight into how major nutrients, such as phosphorus (P), constrain leaf CO2 assimilation rates (Anet). However, triose-phosphate limitations are rarely employed in the classic photosynthesis model and it is uncertain as to what extent these limitations occur in field situations. In contrast to predictions from biochemical theory of photosynthesis, we found consistent evidence in the field of lower Anet in high [CO2] and low [O2 ] than at ambient [O2 ]. For 10 species of trees and shrubs across a range of soil P availability in Australia, none of them showed a positive response of Anet at saturating [CO2] (i.e. Amax) to 2 kPa O2. Three species showed >20% reductions in Amax in low [O2], a phenomenon potentially explained by orthophosphate (Pi) savings during photorespiration. These species, with largest photosynthetic capacity and Pi  > 2 mmol P m(-2), rely the most on additional Pi made available from photorespiration rather than species growing in P-impoverished soils. The results suggest that rarely used adjustments to a biochemical photosynthesis model are useful for predicting Amax and give insight into the biochemical limitations of photosynthesis rates at a range of leaf P concentrations. Phosphate limitations to photosynthetic capacity are likely more common in the field than previously considered.

  18. Taming the fear of voice: Dilemmas in maintaining a high vaccination rate in the Netherlands.

    PubMed

    Geelen, Els; van Vliet, Hans; de Hoogh, Pieter; Horstman, Klasien

    2016-03-01

    In the context of international public debates on vaccination the National Institute for Public Health and the Environment (RIVM), the Dutch public health body responsible for the National Immunization Programme (NIP), fears that the high vaccination rate of children in the Netherlands obscures the many doubts and criticisms parents may have about vaccination. The question arises as to how the robustness of this vaccination rate and the resilience of the NIP can be assessed. To answer this question, we explore the vaccination practices and relationships between professionals and parents using qualitative methods. Drawing on Hirschman's concepts of exit, voice and loyalty, we distinguish between two different approaches to vaccination: one which enforces parental loyalty to the vaccination programme, and one which allows for voice. The analysis shows that due to their lack of voice in the main vaccination setting, parents' considerations are unknown and insight into their loyalty is lacking. We argue that the Dutch vaccination programme is caught between the insecurity of enforced parental loyalty to the NIP and the insecurity of enabling parental voice and negotiating space. We conclude that to increase the resilience of the NIP, experimenting with voice and exit is inevitable.

  19. Ontogenetic changes in the olfactory antennules of the shore crab, Hemigrapsus oregonensis, maintain sniffing function during growth

    PubMed Central

    Waldrop, Lindsay D.; Hann, Miranda; Henry, Amy K.; Kim, Agnes; Punjabi, Ayesha; Koehl, M. A. R.

    2015-01-01

    Malacostracan crustaceans capture odours using arrays of chemosensory hairs (aesthetascs) on antennules. Lobsters and stomatopods have sparse aesthetascs on long antennules that flick with a rapid downstroke when water flows between the aesthetascs and a slow return stroke when water is trapped within the array (sniffing). Changes in velocity only cause big differences in flow through an array in a critical range of hair size, spacing and speed. Crabs have short antennules bearing dense arrays of flexible aesthetascs that splay apart during downstroke and clump together during return. Can crabs sniff, and when during ontogeny are they big enough to sniff? Antennules of Hemigrapsus oregonensis representing an ontogenetic series from small juveniles to adults were used to design dynamically scaled physical models. Particle image velocimetry quantified fluid flow through each array and showed that even very small crabs capture a new water sample in their arrays during the downstroke and retain that sample during return stroke. Comparison with isometrically scaled antennules suggests that reduction in aesthetasc flexural stiffness during ontogeny, in addition to increase in aesthetasc number and decrease in relative size, maintain sniffing as crabs grow. Sniffing performance of intermediate-sized juveniles was worse than for smaller and larger crabs. PMID:25411408

  20. Wheat cultivars selected for high Fv /Fm under heat stress maintain high photosynthesis, total chlorophyll, stomatal conductance, transpiration and dry matter.

    PubMed

    Sharma, Dew Kumari; Andersen, Sven Bode; Ottosen, Carl-Otto; Rosenqvist, Eva

    2015-02-01

    The chlorophyll fluorescence parameter Fv /Fm reflects the maximum quantum efficiency of photosystem II (PSII) photochemistry and has been widely used for early stress detection in plants. Previously, we have used a three-tiered approach of phenotyping by Fv /Fm to identify naturally existing genetic variation for tolerance to severe heat stress (3 days at 40°C in controlled conditions) in wheat (Triticum aestivum L.). Here we investigated the performance of the previously selected cultivars (high and low group based on Fv /Fm value) in terms of growth and photosynthetic traits under moderate heat stress (1 week at 36/30°C day/night temperature in greenhouse) closer to natural heat waves in North-Western Europe. Dry matter accumulation after 7 days of heat stress was positively correlated to Fv /Fm . The high Fv /Fm group maintained significantly higher total chlorophyll and net photosynthetic rate (PN ) than the low group, accompanied by higher stomatal conductance (gs ), transpiration rate (E) and evaporative cooling of the leaf (ΔT). The difference in PN between the groups was not caused by differences in PSII capacity or gs as the variation in Fv /Fm and intracellular CO2 (Ci ) was non-significant under the given heat stress. This study validated that our three-tiered approach of phenotyping by Fv /Fm performed under increasing severity of heat was successful in identifying wheat cultivars differing in photosynthesis under moderate and agronomically more relevant heat stress. The identified cultivars may serve as a valuable resource for further studies to understand the physiological mechanisms underlying the genetic variability in heat sensitivity of photosynthesis. © 2014 Scandinavian Plant Physiology Society.

  1. Populus species from diverse habitats maintain high night-time conductance under drought.

    PubMed

    Cirelli, Damián; Equiza, María Alejandra; Lieffers, Victor James; Tyree, Melvin Thomas

    2016-02-01

    We investigated the interspecific variability in nocturnal whole-plant stomatal conductance under well-watered and drought conditions in seedlings of four species of Populus from habitats characterized by abundant water supply (mesic and riparian) or from drier upland sites. The study was carried out to determine whether (i) nocturnal conductance varies across different species of Populus according to their natural habitat, (ii) nocturnal conductance is affected by water stress similarly to daytime conductance based on species habitat and (iii) differences in conductance among species could be explained partly by differences in stomatal traits. We measured whole-plant transpiration and conductance (G) of greenhouse-grown seedlings using an automated high-resolution gravimetric technique. No relationship was found between habitat preference and daytime G (GD), but night-time G (GN) was on average 1.5 times higher in riparian and mesic species (P. deltoides Bartr. ex Marsh. and P. trichocarpa Torr. & Gray) than in those from drier environments (P. tremuloides Michx. and P. × petrowskyana Schr.). GN was not significantly reduced under drought in riparian species. Upland species restricted GN significantly in response to drought, but it was still at least one order of magnitude greater that the cuticular conductance until leaf death was imminent. Under both well-watered and drought conditions, GN declined with increasing vapour pressure deficit (D). Also, a small increase in GN towards the end of the night period was observed in P. deltoides and P. × petrowskyana, suggesting the involvement of endogenous regulation. The anatomical analyses indicated a positive correlation between G and variable stomatal pore index among species and revealed that stomata are not likely to be leaky but instead seem capable of complete occlusion, which raises the question of the possible physiological role of the significant GN observed under drought. Further comparisons among

  2. Culture of bovine ovarian follicle wall sections maintained the highly estrogenic profile under basal and chemically defined conditions.

    PubMed

    Vasconcelos, R B; Salles, L P; Oliveira e Silva, I; Gulart, L V M; Souza, D K; Torres, F A G; Bocca, A L; Rosa e Silva, A A M

    2013-08-01

    Follicle cultures reproduce in vitro the functional features observed in vivo. In a search for an ideal model, we cultured bovine antral follicle wall sections (FWS) in a serum-free defined medium (DM) known to induce 17β-estradiol (E2) production, and in a nondefined medium (NDM) containing serum. Follicles were sectioned and cultured in NDM or DM for 24 or 48 h. Morphological features were determined by light microscopy. Gene expression of steroidogenic enzymes and follicle-stimulating hormone (FSH) receptor were determined by RT-PCR; progesterone (P4) and E2 concentrations in the media were measured by radioimmunoassay. DM, but not NDM, maintained an FWS morphology in vitro that was similar to fresh tissue. DM also induced an increase in the expression of all steroidogenic enzymes, except FSH receptor, but NDM did not. In both DM and NDM, there was a gradual increase in P4 throughout the culture period; however, P4 concentration was significantly higher in NDM. In both media, E2 concentration was increased at 24 h, followed by a decrease at 48 h. The E2:P4 ratio was higher in DM than in NDM. These results suggest that DM maintains morphological structure, upregulates the expression of steroidogenic enzyme genes, and maintains steroid production with a high E2:P4 ratio in FWS cultures.

  3. Culture of bovine ovarian follicle wall sections maintained the highly estrogenic profile under basal and chemically defined conditions

    PubMed Central

    Vasconcelos, R.B.; Salles, L.P.; Silva, I. Oliveira e; Gulart, L.V.M.; Souza, D.K.; Torres, F.A.G.; Bocca, A.L.; Silva, A.A.M. Rosa e

    2013-01-01

    Follicle cultures reproduce in vitro the functional features observed in vivo. In a search for an ideal model, we cultured bovine antral follicle wall sections (FWS) in a serum-free defined medium (DM) known to induce 17β-estradiol (E2) production, and in a nondefined medium (NDM) containing serum. Follicles were sectioned and cultured in NDM or DM for 24 or 48 h. Morphological features were determined by light microscopy. Gene expression of steroidogenic enzymes and follicle-stimulating hormone (FSH) receptor were determined by RT-PCR; progesterone (P4) and E2 concentrations in the media were measured by radioimmunoassay. DM, but not NDM, maintained an FWS morphology in vitro that was similar to fresh tissue. DM also induced an increase in the expression of all steroidogenic enzymes, except FSH receptor, but NDM did not. In both DM and NDM, there was a gradual increase in P4 throughout the culture period; however, P4 concentration was significantly higher in NDM. In both media, E2 concentration was increased at 24 h, followed by a decrease at 48 h. The E2:P4 ratio was higher in DM than in NDM. These results suggest that DM maintains morphological structure, upregulates the expression of steroidogenic enzyme genes, and maintains steroid production with a high E2:P4 ratio in FWS cultures. PMID:23969977

  4. Maintaining high moisture content of macadamia nuts-in-shell during storage induces brown centres in raw kernels.

    PubMed

    Walton, David A; Randall, Bruce W; Le Lagadec, Marie D; Wallace, Helen M

    2013-09-01

    Kernel brown centres in macadamia are a defect causing internal discolouration of kernels. This study investigates the effect on the incidence of brown centres in raw kernel after maintaining high moisture content in macadamia nuts-in-shell stored at temperatures of 30°C, 35°C, 40°C and 45°C. Brown centres of raw kernel increased with nuts-in-shell storage time and temperature when high moisture content was maintained by sealing in polyethylene bags. Almost all kernels developed the defect when kept at high moisture content for 5 days at 45°C, and 44% developed brown centres after only 2 days of storage at high moisture content at 45°C. This contrasted with only 0.76% when stored for 2 days at 45°C but allowed to dry in open-mesh bags. At storage temperatures below 45°C, there were fewer brown centres, but there were still significant differences between those stored at high moisture content and those allowed to dry (P < 0.05). Maintenance of high moisture content during macadamia nuts-in-shell storage increases the incidence of brown centres in raw kernels and the defect increases with time and temperature. On-farm nuts-in-shell drying and storage practices should rapidly remove moisture to reduce losses. Ideally, nuts-in-shell should not be stored at high moisture content on-farm at temperatures over 30°C. © 2013 Society of Chemical Industry.

  5. GCN2 is required to increase fibroblast growth factor 21 and maintain hepatic triglyceride homeostasis during asparaginase treatment.

    PubMed

    Wilson, Gabriel J; Lennox, Brittany A; She, Pengxiang; Mirek, Emily T; Al Baghdadi, Rana J T; Fusakio, Michael E; Dixon, Joseph L; Henderson, Gregory C; Wek, Ronald C; Anthony, Tracy G

    2015-02-15

    The antileukemic agent asparaginase triggers the amino acid response (AAR) in the liver by activating the eukaryotic initiation factor 2 (eIF2) kinase general control nonderepressible 2 (GCN2). To explore the mechanism by which AAR induction is necessary to mitigate hepatic lipid accumulation and prevent liver dysfunction during continued asparaginase treatment, wild-type and Gcn2 null mice were injected once daily with asparaginase or phosphate buffered saline for up to 14 days. Asparaginase induced mRNA expression of multiple AAR genes and greatly increased circulating concentrations of the metabolic hormone fibroblast growth factor 21 (FGF21) independent of food intake. Loss of Gcn2 precluded mRNA expression and circulating levels of FGF21 and blocked mRNA expression of multiple genes regulating lipid synthesis and metabolism including Fas, Ppara, Pparg, Acadm, and Scd1 in both liver and white adipose tissue. Furthermore, rates of triglyceride export and protein expression of apolipoproteinB-100 were significantly reduced in the livers of Gcn2 null mice treated with asparaginase, providing a mechanistic basis for the increase in hepatic lipid content. Loss of AAR-regulated antioxidant defenses in Gcn2 null livers was signified by reduced Gpx1 gene expression alongside increased lipid peroxidation. Substantial reductions in antithrombin III hepatic expression and activity in the blood of asparaginase-treated Gcn2 null mice indicated liver dysfunction. These results suggest that the ability of the liver to adapt to prolonged asparaginase treatment is influenced by GCN2-directed regulation of FGF21 and oxidative defenses, which, when lost, corresponds with maladaptive effects on lipid metabolism and hemostasis.

  6. Mechanisms of maintaining high suspended sediment concentration over tide-dominated offshore shoals in the southern Yellow Sea

    NASA Astrophysics Data System (ADS)

    Xiong, Jilian; Wang, Xiao Hua; Wang, Ya Ping; Chen, Jingdong; Shi, Benwei; Gao, Jianhua; Yang, Yang; Yu, Qian; Li, Mingliang; Yang, Lei; Gong, Xulong

    2017-05-01

    An understanding of the dynamics and behaviors of suspended sediments is vital in analysis of morphological, environmental, and ecological processes occurring in coastal marine environments. To study the mechanisms of maintaining high suspended sediment concentrations (SSCs) on a tide-dominated offshore shoal, we measured water depths, current velocities, SSCs, wave parameters and bottom sediment compositions in the southern Yellow Sea. These data were then used to calculate bottom shear stresses generated by currents (τc), waves (τw), and wave-current interactions (τcw). SSCs time series exhibited strong quarter-diurnal peaks during spring tides, in contrast to the semidiurnal signal during neap tides. A Fourier analysis showed that suspended sediment variations within tidal cycles was mainly controlled by resuspension in most stations. There existed relatively stable background SSCs (maintaining high SSCs among tidal cycles) values at all four stations during both windy (wind speed > 9.0 m/s) and normal weather conditions (wind speed < 3.0 m/s). The background SSCs had strong relationship with spring/neap-averaged τcw, indicating background SSCs were mainly controlled by mean bottom shear stress, with a minimum value of 0.21 N/m2. On account of the strong tidal currents, background SSCs of spring tides were greater than that of neap tides. In addition, on the base of wavelet, statistics analyses and turbulence dissipation parameter, background SSCs during slack tide in the study area may be maintained by intermittent turbulence events induced by a combined tidal current and wave action.

  7. The Nerve Growth Factor Receptor CD271 Is Crucial to Maintain Tumorigenicity and Stem-Like Properties of Melanoma Cells

    PubMed Central

    Behrens, Diana; Fichtner, Iduna; Przybilla, Dorothea; Wruck, Wasco; Yaspo, Marie-Laure; Lehrach, Hans; Schäfer, Reinhold; Regenbrecht, Christian R. A.

    2014-01-01

    Background Large-scale genomic analyses of patient cohorts have revealed extensive heterogeneity between individual tumors, contributing to treatment failure and drug resistance. In malignant melanoma, heterogeneity is thought to arise as a consequence of the differentiation of melanoma-initiating cells that are defined by cell-surface markers like CD271 or CD133. Results Here we confirmed that the nerve growth factor receptor (CD271) is a crucial determinant of tumorigenicity, stem-like properties, heterogeneity and plasticity in melanoma cells. Stable shRNA mediated knock-down of CD271 in patient-derived melanoma cells abrogated their tumor-initiating and colony-forming capacity. A genome-wide expression profiling and gene-set enrichment analysis revealed novel connections of CD271 with melanoma-associated genes like CD133 and points to a neural crest stem cell (NCSC) signature lost upon CD271 knock-down. In a meta-analysis we have determined a shared set of 271 differentially regulated genes, linking CD271 to SOX10, a marker that specifies the neural crest. To dissect the connection of CD271 and CD133 we have analyzed 10 patient-derived melanoma-cell strains for cell-surface expression of both markers compared to established cell lines MeWo and A375. We found CD271+ cells in the majority of cell strains analyzed as well as in a set of 16 different patient-derived melanoma metastases. Strikingly, only 2/12 cell strains harbored a CD133+ sub-set that in addition comprised a fraction of cells of a CD271+/CD133+ phenotype. Those cells were found in the label-retaining fraction and in vitro deduced from CD271+ but not CD271 knock-down cells. Conclusions Our present study provides a deeper insight into the regulation of melanoma cell properties and points CD271 out as a regulator of several melanoma-associated genes. Further, our data strongly suggest that CD271 is a crucial determinant of stem-like properties of melanoma cells like colony-formation and tumorigenicity

  8. The nerve growth factor receptor CD271 is crucial to maintain tumorigenicity and stem-like properties of melanoma cells.

    PubMed

    Redmer, Torben; Welte, Yvonne; Behrens, Diana; Fichtner, Iduna; Przybilla, Dorothea; Wruck, Wasco; Yaspo, Marie-Laure; Lehrach, Hans; Schäfer, Reinhold; Regenbrecht, Christian R A

    2014-01-01

    Large-scale genomic analyses of patient cohorts have revealed extensive heterogeneity between individual tumors, contributing to treatment failure and drug resistance. In malignant melanoma, heterogeneity is thought to arise as a consequence of the differentiation of melanoma-initiating cells that are defined by cell-surface markers like CD271 or CD133. Here we confirmed that the nerve growth factor receptor (CD271) is a crucial determinant of tumorigenicity, stem-like properties, heterogeneity and plasticity in melanoma cells. Stable shRNA mediated knock-down of CD271 in patient-derived melanoma cells abrogated their tumor-initiating and colony-forming capacity. A genome-wide expression profiling and gene-set enrichment analysis revealed novel connections of CD271 with melanoma-associated genes like CD133 and points to a neural crest stem cell (NCSC) signature lost upon CD271 knock-down. In a meta-analysis we have determined a shared set of 271 differentially regulated genes, linking CD271 to SOX10, a marker that specifies the neural crest. To dissect the connection of CD271 and CD133 we have analyzed 10 patient-derived melanoma-cell strains for cell-surface expression of both markers compared to established cell lines MeWo and A375. We found CD271+ cells in the majority of cell strains analyzed as well as in a set of 16 different patient-derived melanoma metastases. Strikingly, only 2/12 cell strains harbored a CD133+ sub-set that in addition comprised a fraction of cells of a CD271+/CD133+ phenotype. Those cells were found in the label-retaining fraction and in vitro deduced from CD271+ but not CD271 knock-down cells. Our present study provides a deeper insight into the regulation of melanoma cell properties and points CD271 out as a regulator of several melanoma-associated genes. Further, our data strongly suggest that CD271 is a crucial determinant of stem-like properties of melanoma cells like colony-formation and tumorigenicity.

  9. Palovarotene Inhibits Heterotopic Ossification and Maintains Limb Mobility and Growth in Mice With the Human ACVR1(R206H) Fibrodysplasia Ossificans Progressiva (FOP) Mutation.

    PubMed

    Chakkalakal, Salin A; Uchibe, Kenta; Convente, Michael R; Zhang, Deyu; Economides, Aris N; Kaplan, Frederick S; Pacifici, Maurizio; Iwamoto, Masahiro; Shore, Eileen M

    2016-09-01

    Fibrodysplasia ossificans progressiva (FOP), a rare and as yet untreatable genetic disorder of progressive extraskeletal ossification, is the most disabling form of heterotopic ossification (HO) in humans and causes skeletal deformities, movement impairment, and premature death. Most FOP patients carry an activating mutation in a bone morphogenetic protein (BMP) type I receptor gene, ACVR1(R206H) , that promotes ectopic chondrogenesis and osteogenesis and, in turn, HO. We showed previously that the retinoic acid receptor γ (RARγ) agonist palovarotene effectively inhibited HO in injury-induced and genetic mouse models of the disease. Here we report that the drug additionally prevents spontaneous HO, using a novel conditional-on knock-in mouse line carrying the human ACVR1(R206H) mutation for classic FOP. In addition, palovarotene restored long bone growth, maintained growth plate function, and protected growing mutant neonates when given to lactating mothers. Importantly, palovarotene maintained joint, limb, and body motion, providing clear evidence for its encompassing therapeutic potential as a treatment for FOP. © 2016 American Society for Bone and Mineral Research.

  10. The Sclerophyllous Eucalyptus camaldulensis and Herbaceous Nicotiana tabacum Have Different Mechanisms to Maintain High Rates of Photosynthesis

    PubMed Central

    Huang, Wei; Tong, You-Gui; Yu, Guo-Yun; Yang, Wei-Xian

    2016-01-01

    It is believed that high levels of mesophyll conductance (gm) largely contribute to the high rates of photosynthesis in herbaceous C3 plants. However, some sclerophyllous C3 plants that display low levels of gm have high rates of photosynthesis, and the underlying mechanisms responsible for high photosynthetic rates in sclerophyllous C3 plants are unclear. In the present study, we examined photosynthetic characteristics in two high-photosynthesis plants (the sclerophyllous Eucalyptus camaldulensis and the herbaceous Nicotiana tabacum) using measurements of gas exchange and chlorophyll fluorescence. Under saturating light intensities, both species had similar rates of CO2 assimilation at 400 μmol mol−1 CO2 (A400). However, E. camaldulensis exhibited significantly lower gm and chloroplast CO2 concentration (Cc) than N. tabacum. A quantitative analysis revealed that, in E. camaldulensis, the gm limitation was the most constraining factor for photosynthesis. By comparison, in N. tabacum, the biochemical limitation was the strongest, followed by gm and gs limitations. In conjunction with a lower Cc, E. camaldulensis up-regulated the capacities of photorespiratory pathway and alternative electron flow. Furthermore, the rate of alternative electron flow was positively correlated with the rates of photorespiration and ATP supply from other flexible mechanisms, suggesting the important roles of photorespiratory pathway, and alternative electron flow in sustaining high rate of photosynthesis in E. camaldulensis. These results highlight the different mechanisms used to maintain high rates of photosynthesis in the sclerophyllous E. camaldulensis and the herbaceous N. tabacum. PMID:27933083

  11. A Wheat SIMILAR TO RCD-ONE Gene Enhances Seedling Growth and Abiotic Stress Resistance by Modulating Redox Homeostasis and Maintaining Genomic Integrity[C][W

    PubMed Central

    Liu, Shuantao; Liu, Shuwei; Wang, Mei; Wei, Tiandi; Meng, Chen; Wang, Meng; Xia, Guangmin

    2014-01-01

    Plant growth inhibition is a common response to salinity. Under saline conditions, Shanrong No. 3 (SR3), a bread wheat (Triticum aestivum) introgression line, performs better than its parent wheat variety Jinan 177 (JN177) with respect to both seedling growth and abiotic stress tolerance. Furthermore, the endogenous reactive oxygen species (ROS) was also elevated in SR3 relative to JN177. The SR3 allele of sro1, a gene encoding a poly(ADP ribose) polymerase (PARP) domain protein, was identified to be crucial for both aspects of its superior performance. Unlike RADICAL-INDUCED CELL DEATH1 and other Arabidopsis thaliana SIMILAR TO RCD-ONE (SRO) proteins, sro1 has PARP activity. Both the overexpression of Ta-sro1 in wheat and its heterologous expression in Arabidopsis promote the accumulation of ROS, mainly by enhancing the activity of NADPH oxidase and the expression of NAD(P)H dehydrogenase, in conjunction with the suppression of alternative oxidase expression. Moreover, it promotes the activity of ascorbate-GSH cycle enzymes and GSH peroxidase cycle enzymes, which regulate ROS content and cellular redox homeostasis. sro1 is also found to be involved in the maintenance of genomic integrity. We show here that the wheat SRO has PARP activity; such activity could be manipulated to improve the growth of seedlings exposed to salinity stress by modulating redox homeostasis and maintaining genomic stability. PMID:24443520

  12. A wheat SIMILAR TO RCD-ONE gene enhances seedling growth and abiotic stress resistance by modulating redox homeostasis and maintaining genomic integrity.

    PubMed

    Liu, Shuantao; Liu, Shuwei; Wang, Mei; Wei, Tiandi; Meng, Chen; Wang, Meng; Xia, Guangmin

    2014-01-01

    Plant growth inhibition is a common response to salinity. Under saline conditions, Shanrong No. 3 (SR3), a bread wheat (Triticum aestivum) introgression line, performs better than its parent wheat variety Jinan 177 (JN177) with respect to both seedling growth and abiotic stress tolerance. Furthermore, the endogenous reactive oxygen species (ROS) was also elevated in SR3 relative to JN177. The SR3 allele of sro1, a gene encoding a poly(ADP ribose) polymerase (PARP) domain protein, was identified to be crucial for both aspects of its superior performance. Unlike RADICAL-INDUCED CELL DEATH1 and other Arabidopsis thaliana SIMILAR TO RCD-ONE (SRO) proteins, sro1 has PARP activity. Both the overexpression of Ta-sro1 in wheat and its heterologous expression in Arabidopsis promote the accumulation of ROS, mainly by enhancing the activity of NADPH oxidase and the expression of NAD(P)H dehydrogenase, in conjunction with the suppression of alternative oxidase expression. Moreover, it promotes the activity of ascorbate-GSH cycle enzymes and GSH peroxidase cycle enzymes, which regulate ROS content and cellular redox homeostasis. sro1 is also found to be involved in the maintenance of genomic integrity. We show here that the wheat SRO has PARP activity; such activity could be manipulated to improve the growth of seedlings exposed to salinity stress by modulating redox homeostasis and maintaining genomic stability.

  13. Maintaining exponential growth, solution conductivity, and solution pH in low-ionic-strength solution culture using a computer-controlled nutrient delivery system.

    PubMed

    Blair, Laura M; Taylor, Gregory J

    2004-07-01

    Studies of plant nutrient requirements in solution culture have often used nutrient concentrations many-fold higher than levels found in fertile soils, creating an artificial rooting environment that can alter patterns of nutrient acquisition. The relative addition rate (RAR) technique addresses this problem by providing nutrients in exponentially increasing quantities to plant roots in solution culture. A computer-controlled RAR nutrient delivery system has been developed to reduce workload and to facilitate more frequent nutrient additions (4x daily) than is possible with manual additions. In initial experiments, a minimum background solution containing 500 microM nitrogen and all other essential nutrients in optimal proportions was required for the healthy growth of Triticum aestivum. This requirement was reduced to 50 microM nitrogen when calcium in the background solutions was increased to 400 microM. Varying the abundance of ammonium and nitrate in both background and delivery solutions provided a means of controlling plant-induced pH changes in growth solutions. In optimized solutions, plant relative growth rates (RGR) in the order of 0.2 g g(-1) plant d(-1) were maintained over a 22 d experimental period. Variation in RARs provided a means of growing plants with varying RGRs under relatively constant conditions of solution electrical conductivity and pH.

  14. A mutant of Chlamydomonas without LHCSR maintains high rates of photosynthesis, but has reduced cell division rates in sinusoidal light conditions.

    PubMed

    Cantrell, Michael; Peers, Graham

    2017-01-01

    The LHCSR protein belongs to the light harvesting complex family of pigment-binding proteins found in oxygenic photoautotrophs. Previous studies have shown that this complex is required for the rapid induction and relaxation of excess light energy dissipation in a wide range of eukaryotic algae and moss. The ability of cells to rapidly regulate light harvesting between this dissipation state and one favoring photochemistry is believed to be important for reducing oxidative stress and maintaining high photosynthetic efficiency in a rapidly changing light environment. We found that a mutant of Chlamydomonas reinhardtii lacking LHCSR, npq4lhcsr1, displays minimal photoinhibition of photosystem II and minimal inhibition of short term oxygen evolution when grown in constant excess light compared to a wild type strain. We also investigated the impact of no LHCSR during growth in a sinusoidal light regime, which mimics daily changes in photosynthetically active radiation. The absence of LHCSR correlated with a slight reduction in the quantum efficiency of photosystem II and a stimulation of the maximal rates of photosynthesis compared to wild type. However, there was no reduction in carbon accumulation during the day. Another novel finding was that npq4lhcsr1 cultures underwent fewer divisions at night, reducing the overall growth rate compared to the wild type. Our results show that the rapid regulation of light harvesting mediated by LHCSR is required for high growth rates, but it is not required for efficient carbon accumulation during the day in a sinusoidal light environment. This finding has direct implications for engineering strategies directed at increasing photosynthetic productivity in mass cultures.

  15. Long-term sphere culture cannot maintain a high ratio of cancer stem cells: a mathematical model and experiment.

    PubMed

    Peng, Tang; Qinghua, Ma; Zhenning, Tang; Kaifa, Wang; Jun, Jiang

    2011-01-01

    Acquiring abundant and high-purity cancer stem cells (CSCs) is an important prerequisite for CSC research. At present, researchers usually gain high-purity CSCs through flow cytometry sorting and expand them by short-term sphere culture. However, it is still uncertain whether we can amplify high-purity CSCs through long-term sphere culture. We have proposed a mathematical model using ordinary differential equations to derive the continuous variation of the CSC ratio in long-term sphere culture and estimated the model parameters based on a long-term sphere culture of MCF-7 stem cells. We found that the CSC ratio in long-term sphere culture presented as gradually decreased drift and might be stable at a lower level. Furthermore, we found that fitted model parameters could explain the main growth pattern of CSCs and differentiated cancer cells in long-term sphere culture.

  16. Highly Dynamic Interactions Maintain Kinetic Stability of the ClpXP Protease During the ATP-Fueled Mechanical Cycle.

    PubMed

    Amor, Alvaro J; Schmitz, Karl R; Sello, Jason K; Baker, Tania A; Sauer, Robert T

    2016-06-17

    The ClpXP protease assembles in a reaction in which an ATP-bound ring hexamer of ClpX binds to one or both heptameric rings of the ClpP peptidase. Contacts between ClpX IGF-loops and clefts on a ClpP ring stabilize the complex. How ClpXP stability is maintained during the ATP-hydrolysis cycle that powers mechanical unfolding and translocation of protein substrates is poorly understood. Here, we use a real-time kinetic assay to monitor the effects of nucleotides on the assembly and disassembly of ClpXP. When ATP is present, complexes containing single-chain ClpX assemble via an intermediate and remain intact until transferred into buffers containing ADP or no nucleotides. ATP binding to high-affinity subunits of the ClpX hexamer prevents rapid dissociation, but additional subunits must be occupied to promote assembly. Small-molecule acyldepsipeptides, which compete with the IGF loops of ClpX for ClpP-cleft binding, cause exceptionally rapid dissociation of otherwise stable ClpXP complexes, suggesting that the IGF-loop interactions with ClpP must be highly dynamic. Our results indicate that the ClpX hexamer spends almost no time in an ATP-free state during the ATPase cycle, allowing highly processive degradation of protein substrates.

  17. Role of Internal Potassium in Maintaining Growth of Cultured Citrus Cells on Increasing NaCl and CaCl2 Concentrations 1

    PubMed Central

    Ben-Hayyim, Gozal; Kafkafi, Uzi; Ganmore-Neumann, Ruth

    1987-01-01

    Shamouti orange (Citrus sinensis L. Osbeck) salt-tolerant cells were grown under low water potential conditions induced by polyethylene glycol (PEG), NaCl, and CaCl2. On the basis of equal osmotic potentials, PEG was the least inhibitory, NaCl next, and CaCl2 the most inhibitory. The relation between growth capacity and ion content can be summarized as follows. (a) Internal K+ concentration was a major factor which changed in the presence of PEG, NaCl, and CaCl2 and probably played a key role in determining growth capacity. (b) Internal concentrations of Na+, Ca2+, or Cl− could not be directly correlated with growth. (C) Internal Mg2+ concentration could be significant only in the presence of high external Ca2+ concentrations. (d) The contribution of nitrate and phosphate to the internal osmoticum was negligible. The ratio of external (Ca2+)/(Na+)2 concentration is crucial for growth. Ratios above 0.5 × 10−4 per millimolar gave maximal protection from adverse effects of NaCl. Growth capacity was found to be determined by the combination of (Ca2+)/(Na+)2 ratio and the absolute external concentration of NaCl. However, a correlation between internal K+ concentration and growth capacity seemed independent of external NaCl concentration. PMID:16665716

  18. Sequential nutrient uptake as a potential mechanism for phytoplankton to maintain high primary productivity and balanced nutrient stoichiometry

    NASA Astrophysics Data System (ADS)

    Yin, Kedong; Liu, Hao; Harrison, Paul J.

    2017-05-01

    We hypothesize that phytoplankton have the sequential nutrient uptake strategy to maintain nutrient stoichiometry and high primary productivity in the water column. According to this hypothesis, phytoplankton take up the most limiting nutrient first until depletion, continue to draw down non-limiting nutrients and then take up the most limiting nutrient rapidly when it is available. These processes would result in the variation of ambient nutrient ratios in the water column around the Redfield ratio. We used high-resolution continuous vertical profiles of nutrients, nutrient ratios and on-board ship incubation experiments to test this hypothesis in the Strait of Georgia. At the surface in summer, ambient NO3- was depleted with excess PO43- and SiO4- remaining, and as a result, both N : P and N : Si ratios were low. The two ratios increased to about 10 : 1 and 0. 45 : 1, respectively, at 20 m. Time series of vertical profiles showed that the leftover PO43- continued to be removed, resulting in additional phosphorus storage by phytoplankton. The N : P ratios at the nutricline in vertical profiles responded differently to mixing events. Field incubation of seawater samples also demonstrated the sequential uptake of NO3- (the most limiting nutrient) and then PO43- and SiO4- (the non-limiting nutrients). This sequential uptake strategy allows phytoplankton to acquire additional cellular phosphorus and silicon when they are available and wait for nitrogen to become available through frequent mixing of NO3- (or pulsed regenerated NH4). Thus, phytoplankton are able to maintain high productivity and balance nutrient stoichiometry by taking advantage of vigorous mixing regimes with the capacity of the stoichiometric plasticity. To our knowledge, this is the first study to show the in situ dynamics of continuous vertical profiles of N : P and N : Si ratios, which can provide insight into the in situ dynamics of nutrient stoichiometry in the water column and the inference of

  19. Achieving and Maintaining Deep Space 1 Spacecraft High-Gain Antenna Pointing Control by Data Monitoring and Immediate Corrective Commanding

    NASA Astrophysics Data System (ADS)

    Taylor, J.; Ko, P.

    2000-10-01

    The Deep Space 1 (DS1) onboard stellar reference unit failed in November 1999, leaving the spacecraft able to achieve only Sun point, with 8.4 GHz (X-band) communications reduced to the low rates supportable via a low-gain antenna. By January 2000, the DS1 project fight team implemented an interim three-axis pointing concept called the "HGA activity" because it made the high-gain antenna (HGA) usable again. The HGA activity involves the telecommunications analyst as an integral part of a closed-loop ground--spacecraft pointing control system. The HGA activity initiates pointing of the high-gain antenna toward the Earth and subsequently maintains pointing for the duration of one or two passes. The concept requires the tracking station to lock its receiver on the X-band carrier and provide carrier signal-to-noise ratio in monitor data in real time. The project telecommunications analyst uses the data to prepare accurate event timing predictions and to assess performance through rapid and precise comparisons of monitor and prediction data. Use of this labor-intensive and real-time process enabled the project to receive high-rate telemetry data from 14 passes through May 2000. Finally, another 14 HGA activities in June 2000 enabled the project to reload several megabytes of flight software at a high rate. The new software brought to an end the routine use of the HGA activity because it operates the science camera to generate star data for onboard pointing control. With full three-axis pointing capability restored for ion-propulsion subsystem thrusting, DS1 has resumed its science mission with a flyby of the comet Borrelly planned for September 2001.

  20. Obesity and diabetes as accelerators of functional decline: can lifestyle interventions maintain functional status in high risk older adults?

    PubMed

    Anton, Stephen D; Karabetian, Christy; Naugle, Kelly; Buford, Thomas W

    2013-09-01

    Obesity and diabetes are known risk factors for the development of physical disability among older adults. With the number of seniors with these conditions rising worldwide, the prevention and treatment of physical disability in these persons have become a major public health challenge. Sarcopenia, the progressive loss of muscle mass and strength, has been identified as a common pathway associated with the initial onset and progression of physical disability among older adults. A growing body of evidence suggests that metabolic dysregulation associated with obesity and diabetes accelerates the progression of sarcopenia, and subsequently functional decline in older adults. The focus of this brief review is on the contributions of obesity and diabetes in accelerating sarcopenia and functional decline among older adults. We also briefly discuss the underexplored interaction between obesity and diabetes that may further accelerate sarcopenia and place obese older adults with diabetes at particularly high risk of disability. Finally, we review findings from studies that have specifically tested the efficacy of lifestyle-based interventions in maintaining the functional status of older persons with obesity and/or diabetes.

  1. High dispersal potential has maintained long-term population stability in the North Atlantic copepod Calanus finmarchicus

    PubMed Central

    Provan, Jim; Beatty, Gemma E.; Keating, Sianan L.; Maggs, Christine A.; Savidge, Graham

    2008-01-01

    The cool-water copepod Calanus finmarchicus is a key species in North Atlantic marine ecosystems since it represents an important food resource for the developmental stages of several fish of major economic value. Over the last 40 years, however, data from the Continuous Plankton Recorder survey have highlighted a 70 per cent reduction in C. finmarchicus biomass, coupled with a gradual northward shift in the species's distribution, which have both been linked with climate change. To determine the potential for C. finmarchicus to track changes in habitat availability and maintain stable effective population sizes, we have assessed levels of gene flow and dispersal in current populations, as well as using a coalescent approach together with palaeodistribution modelling to elucidate the historical population demography of the species over previous changes in Earth's climate. Our findings indicate high levels of dispersal and a constant effective population size over the period 359 000–566 000 BP and suggest that C. finmarchicus possesses the capacity to track changes in available habitat, a feature that may be of crucial importance to the species's ability to cope with the current period of global climate change. PMID:18812293

  2. Obesity and Diabetes as Accelerators of Functional Decline; Can Lifestyle Interventions Maintain Functional Status in High Risk Older Adults?

    PubMed Central

    Anton, Stephen D.; Karabetian, Christy; Naugle, Kelly; Buford, Thomas W.

    2013-01-01

    Obesity and diabetes are known risk factors for the development of physical disability among older adults. With the number of seniors with these conditions rising worldwide, the prevention and treatment of physical disability in these persons has become a major public health challenge. Sarcopenia, the progressive loss of muscle mass and strength, has been identified as a common pathway associated with the initial onset and progression of physical disability among older adults. A growing body of evidence suggests that metabolic dysregulation associated with obesity and diabetes accelerates the progression of sarcopenia, and subsequently functional decline in older adults. The focus of this brief review is on the contributions of obesity and diabetes in accelerating sarcopenia and functional decline among older adults. We also briefly discuss the underexplored interaction between obesity and diabetes that may further accelerate sarcopenia and place obese older adults with diabetes at particularly high risk of disability. Finally, we review findings from studies that have specifically tested the efficacy of lifestyle-based interventions in maintaining the functional status of older persons with obesity and/or diabetes. PMID:23832077

  3. Extracellular Vesicles from High-Grade Glioma Exchange Diverse Pro-oncogenic Signals That Maintain Intratumoral Heterogeneity.

    PubMed

    Ricklefs, Franz; Mineo, Marco; Rooj, Arun K; Nakano, Ichiro; Charest, Al; Weissleder, Ralph; Breakefield, Xandra O; Chiocca, E Antonio; Godlewski, Jakub; Bronisz, Agnieszka

    2016-05-15

    A lack of experimental models of tumor heterogeneity limits our knowledge of the complex subpopulation dynamics within the tumor ecosystem. In high-grade gliomas (HGG), distinct hierarchical cell populations arise from different glioma stem-like cell (GSC) subpopulations. Extracellular vesicles (EV) shed by cells may serve as conduits of genetic and signaling communications; however, little is known about how HGG heterogeneity may impact EV content and activity. In this study, we performed a proteomic analysis of EVs isolated from patient-derived GSC of either proneural or mesenchymal subtypes. EV signatures were heterogeneous, but reflected the molecular make-up of the GSC and consistently clustered into the two subtypes. EV-borne protein cargos transferred between proneural and mesenchymal GSC increased protumorigenic behaviors in vitro and in vivo Clinically, analyses of HGG patient data from the The Cancer Genome Atlas database revealed that proneural tumors with mesenchymal EV signatures or mesenchymal tumors with proneural EV signatures were both associated with worse outcomes, suggesting influences by the proportion of tumor cells of varying subtypes in tumors. Collectively, our findings illuminate the heterogeneity among tumor EVs and the complexity of HGG heterogeneity, which these EVs help to maintain. Cancer Res; 76(10); 2876-81. ©2016 AACR. ©2016 American Association for Cancer Research.

  4. Quasi-distributed birefringence dispersion measurement for polarization maintain device with high accuracy based on white light interferometry.

    PubMed

    Yu, Zhangjun; Yang, Jun; Yuan, Yonggui; Li, Chuang; Liang, Shuai; Hou, Lu; Peng, Feng; Wu, Bing; Zhang, Jianzhong; Liu, Zhihai; Yuan, Libo

    2016-01-25

    A white light temporal interferometric technique for measurement of the quasi-distributed birefringence dispersion (BD) in a polarization maintain (PM) device with high accuracy based on weighted least square (WLS) method is presented. It is verified theoretically and experimentally that the accuracy of WLS method and the conventional ordinary least square (OLS) method both are proportional to the signal-to-noise ratio (SNR) of interferogram, whereas the WLS method holds a higher scaling factor because it is more suitable for heteroscedastic model that has unequal error variance. The experiment results show a repeatability of ~4.6 × 10(-5) ps/nm @ 1550 nm with WLS method for 100 sets of data, and ~4.3 × 10(-4) ps/nm with OLS method, for an interferogram with SNR of 30 dB. Besides, WLS method without iterative operation is carried out by using power spectrum of interferogram as weight value. The feasibility of this technique is demonstrated by distinguishing the quasi-distributed BD of every part for a packaged Y-waveguide with two 1m-long PM pigtails.

  5. High-intensity interval training every second week maintains VO2max in soccer players during off-season.

    PubMed

    Slettaløkken, Gunnar; Rønnestad, Bent R

    2014-07-01

    Reduced endurance training among semiprofessional soccer players during off-season may have negative effect on game performance during the competition season. This negative effect can be prevented by adding high-intensity interval training (HIT) to normal activity. In this study, we want to compare 2 different frequencies of HIT (5 bouts of 4 minutes on 87-97% peak heart rate) session on maintenance of aerobic fitness among semiprofessional soccer players during a 6-week off-season period. Seventeen male players at second and third highest soccer division in Norway participated. The subjects were randomized into 1 HIT session every second week (HIT 0.5) or 1 HIT session per week (HIT 1). All participants performed a 20-m shuttle run test and a maximal oxygen uptake (VO2max) test on treadmill before and after the training intervention. VO2max (HIT 0.5, 63.4 ± 5.9 ml·kg-1·min-1; HIT 1, 65.6 ± 2.1 ml·kg-1·min-1) and 20-m shuttle run performance (HIT 0.5, 2335 ± 390 m, HIT 1, 2531 ± 106 m) were not different between the groups before the training intervention. VO2max was maintained after the training intervention in both HIT 0.5 and HIT 1 (64.0 ± 5.9 ml·kg-1·min-1 and 64.3 ± 1.3 ml·kg-1·min-1, respectively). There was a reduction in distance covered during the 20-m shuttle run test in HIT 1 and when groups were pooled (-7.9 ± 5.7% and -6.4 ± 7.9%, respectively, p ≤ 0.05). In conclusion, HIT 1 did not maintain VO2max better than HIT 0.5 when added to normal off-season activity. However, performance in 20-m shuttle run, which is a more soccer-specific fitness test than VO2max test, was slightly reduced when both groups was pooled.

  6. Growth mechanisms of plasma-assisted molecular beam epitaxy of green emission InGaN/GaN single quantum wells at high growth temperatures

    SciTech Connect

    Yang, W. C.; Wu, C. H.; Tseng, Y. T.; Chiu, S. Y.; Cheng, K. Y.

    2015-01-07

    The results of the growth of thin (∼3 nm) InGaN/GaN single quantum wells (SQWs) with emission wavelengths in the green region by plasma-assisted molecular beam epitaxy are present. An improved two-step growth method using a high growth temperature up to 650 °C is developed to increase the In content of the InGaN SQW to 30% while maintaining a strong luminescence intensity near a wavelength of 506 nm. The indium composition in InGaN/GaN SQW grown under group-III-rich condition increases with increasing growth temperature following the growth model of liquid phase epitaxy. Further increase in the growth temperature to 670 °C does not improve the photoluminescence property of the material due to rapid loss of indium from the surface and, under certain growth conditions, the onset of phase separation.

  7. Dynamic 3D visual analytic tools: a method for maintaining situational awareness during high tempo warfare or mass casualty operations

    NASA Astrophysics Data System (ADS)

    Lizotte, Todd E.

    2010-04-01

    Maintaining Situational Awareness (SA) is crucial to the success of high tempo operations, such as war fighting and mass casualty events (bioterrorism, natural disasters). Modern computer and software applications attempt to provide command and control manager's situational awareness via the collection, integration, interrogation and display of vast amounts of analytic data in real-time from a multitude of data sources and formats [1]. At what point does the data volume and displays begin to erode the hierarchical distributive intelligence, command and control structure of the operation taking place? In many cases, people tasked with making decisions, have insufficient experience in SA of high tempo operations and become overwhelmed easily as vast amounts of data begin to be displayed in real-time as an operation unfolds. In these situations, where data is plentiful and the relevance of the data changes rapidly, there is a chance for individuals to target fixate on those data sources they are most familiar. If these individuals fall into this type of pitfall, they will exclude other data that might be just as important to the success of the operation. To counter these issues, it is important that the computer and software applications provide a means for prompting its users to take notice of adverse conditions or trends that are critical to the operation. This paper will discuss a new method of displaying data called a Crisis ViewTM, that monitors critical variables that are dynamically changing and allows preset thresholds to be created to prompt the user when decisions need to be made and when adverse or positive trends are detected. The new method will be explained in basic terms, with examples of its attributes and how it can be implemented.

  8. Sun leaves up-regulate the photorespiratory pathway to maintain a high rate of CO2 assimilation in tobacco.

    PubMed

    Huang, Wei; Zhang, Shi-Bao; Hu, Hong

    2014-01-01

    The greater rate of CO2 assimilation (A n) in sun-grown tobacco leaves leads to lower intercellular and chloroplast CO2 concentrations and, thus, a higher rate of oxygenation of ribulose-1,5-bisphosphate (RuBP) than in shade-grown leaves. Impairment of the photorespiratory pathway suppresses photosynthetic CO2 assimilation. Here, we hypothesized that sun leaves can up-regulate photorespiratory pathway to enhance the A n in tobacco. To test this hypothesis, we examined the responses of photosynthetic electron flow (J T) and CO2 assimilation to incident light intensity and intercellular CO2 concentration (C i) in leaves of 'k326' tobacco plants grown at 95% sunlight (sun plants) or 28% sunlight (shade plants). The sun leaves had higher photosynthetic capacity and electron flow devoted to RuBP carboxylation (J C) than the shade leaves. When exposed to high light, the higher Rubisco (ribulose-1,5-bisphosphate carboxylase/oxygenase) content and lower C i in the sun leaves led to greater electron flow devoted to RuBP oxygenation (J O). The J O/J C ratio was significantly higher in the sun leaves than in the shade leaves under strong illumination. As estimated from CO2-response curves, the maximum J O was linearly correlated with the estimated Rubisco content. Based on light-response curves, the light-saturated J O was linearly correlated with light-saturated J T and light-saturated photosynthesis. These findings indicate that enhancement of the photorespiratory pathway is an important strategy by which sun plants maintain a high A n.

  9. Sox5 and Sox6 are needed to develop and maintain source, columnar, and hypertrophic chondrocytes in the cartilage growth plate.

    PubMed

    Smits, Patrick; Dy, Peter; Mitra, Srijeet; Lefebvre, Véronique

    2004-03-01

    Sox5 and Sox6 encode Sry-related transcription factors that redundantly promote early chondroblast differentiation. Using mouse embryos with three or four null alleles of Sox5 and Sox6, we show that they are also essential and redundant in major steps of growth plate chondrocyte differentiation. Sox5 and Sox6 promote the development of a highly proliferating pool of chondroblasts between the epiphyses and metaphyses of future long bones. This pool is the likely cellular source of growth plates. Sox5 and Sox6 permit formation of growth plate columnar zones by keeping chondroblasts proliferating and by delaying chondrocyte prehypertrophy. They allow induction of chondrocyte hypertrophy and permit formation of prehypertrophic and hypertrophic zones by delaying chondrocyte terminal differentiation induced by ossification fronts. They act, at least in part, by down-regulating Ihh signaling, Fgfr3, and Runx2 and by up-regulating Bmp6. In conclusion, Sox5 and Sox6 are needed for the establishment of multilayered growth plates, and thereby for proper and timely development of endochondral bones.

  10. Platelet-derived growth factor maintains stored calcium through a nonclustering Orai1 mechanism but evokes clustering if the endoplasmic reticulum is stressed by store depletion.

    PubMed

    McKeown, Lynn; Moss, Nicholas K; Turner, Paul; Li, Jing; Heath, Nikki; Burke, Dermot; O'Regan, David; Gilthorpe, Mark S; Porter, Karen E; Beech, David J

    2012-06-22

    Calcium entry through Orai1 channels drives vascular smooth muscle cell migration and neointimal hyperplasia. The channels are activated by the important growth factor platelet-derived growth factor (PDGF). Channel activation is suggested to depend on store depletion, which redistributes and clusters stromal interaction molecule 1 (STIM1), which then coclusters and activates Orai1. To determine the relevance of STIM1 and Orai1 redistribution in PDGF responses. Vascular smooth muscle cells were cultured from human saphenous vein. STIM1 and Orai1 were tagged with green and red fluorescent proteins to track them in live cells. Under basal conditions, the proteins were mobile but mostly independent of each other. Inhibition of sarco-endoplasmic reticulum calcium ATPase led to store depletion and dramatic redistribution of STIM1 and Orai1 into coclusters. PDGF did not evoke redistribution, even though it caused calcium release and Orai1-mediated calcium entry in the same time period. After chemical blockade of Orai1-mediated calcium entry, however, PDGF caused redistribution. Similarly, mutagenic disruption of calcium flux through Orai1 caused PDGF to evoke redistribution, showing that calcium flux through the wild-type channels had been filling the stores. Acidification of the extracellular medium to pH 6.4 caused inhibition of Orai1-mediated calcium entry and conferred capability for PDGF to evoke complete redistribution and coclustering. The data suggest that PDGF has a nonclustering mechanism by which to activate Orai1 channels and maintain calcium stores replete. Redistribution and clustering become important, however, when the endoplasmic reticulum stress signal of store depletion arises, for example when acidosis inhibits Orai1 channels.

  11. Stroma-Derived Connective Tissue Growth Factor Maintains Cell Cycle Progression and Repopulation Activity of Hematopoietic Stem Cells In Vitro.

    PubMed

    Istvánffy, Rouzanna; Vilne, Baiba; Schreck, Christina; Ruf, Franziska; Pagel, Charlotta; Grziwok, Sandra; Henkel, Lynette; Prazeres da Costa, Olivia; Berndt, Johannes; Stümpflen, Volker; Götze, Katharina S; Schiemann, Matthias; Peschel, Christian; Mewes, Hans-Werner; Oostendorp, Robert A J

    2015-11-10

    Hematopoietic stem cells (HSCs) are preserved in co-cultures with UG26-1B6 stromal cells or their conditioned medium. We performed a genome-wide study of gene expression changes of UG26-1B6 stromal cells in contact with Lineage⁻ SCA-1⁺ KIT⁺ (LSK) cells. This analysis identified connective tissue growth factor (CTGF) to be upregulated in response to LSK cells. We found that co-culture of HSCs on CTGF knockdown stroma (shCtgf) shows impaired engraftment and long-term quality. Further experiments demonstrated that CD34⁻ CD48⁻ CD150⁺ LSK (CD34⁻ SLAM) cell numbers from shCtgf co-cultures increase in G0 and senescence and show delayed time to first cell division. To understand this observation, a CTGF signaling network model was assembled, which was experimentally validated. In co-culture experiments of CD34⁻ SLAM cells with shCtgf stromal cells, we found that SMAD2/3-dependent signaling was activated, with increasing p27(Kip1) expression and downregulating cyclin D1. Our data support the view that LSK cells modulate gene expression in the niche to maintain repopulating HSC activity. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  12. Cognitive function is maintained in noninstitutionalized elderly Japanese requiring care with high levels of health-related quality of life.

    PubMed

    Kitamura, Kaori; Nakamura, Kazutoshi; Ueno, Kimiko; Nishiwaki, Tomoko

    2016-11-01

    Health-related quality of life (HRQOL) has been reported to be associated with cognitive function; however, whether or not this relationship involves causality is uncertain. This study aimed to determine whether HRQOL levels are associated with subsequent changes in cognitive function in elderly people requiring care. Participants were 74 community-dwelling elderly people utilizing the long-term care service (69 % women) who underwent physical and psychological examinations at baseline and follow-up. The outcome was 2-year changes in Mini-Mental State Examination (∆MMSE) score. The potential predictor was HRQOL level assessed by the EuroQol 5 dimension (EQ-5D) score (utility value) at baseline; other variables were body mass index (BMI), Barthel index, grip strength, Geriatric Depression Scale, serum albumin, and serum hemoglobin. Associations between EQ-5D and ∆MMSE scores were assessed using correlation analysis, regression analysis, and analysis of covariance (ANCOVA). Mean age, BMI, and Barthel index at baseline were 81.6 years [standard deviation (SD) 8.2], 21.1 kg/m(2) (SD 4.0), and 79 (SD 20), respectively; the mean ∆MMSE score was -2.2 (SD 5.1). EQ-5D was significantly correlated with ∆MMSE (partial r = 0.375, P = 0.0012). The mean ∆MMSE values of the 1st, 2nd, and 3rd EQ-5D quartiles were -4.2 (adjusted P = 0.0050), -2.6 (adjusted P = 0.0476), and -2.4 (adjusted P = 0.0298), respectively, which were lower than the -0.1 of the reference 4th quartile. HRQOL as assessed by EQ-5D is associated with longitudinal cognitive decline in frail elderly people, and cognitive function may be maintained in individuals with high HRQOL levels.

  13. Agricultural sustainable intensification improved nitrogen use efficiency and maintained high crop yield during 1980-2014 in Northern China.

    PubMed

    Zhang, Xin; Bol, Roland; Rahn, Clive; Xiao, Guangmin; Meng, Fanqiao; Wu, Wenliang

    2017-10-15

    Global population increase will require rapid increase of food production from existing agricultural land by 2050, which will inevitably mean the increase of agricultural productivity. Due to agricultural sustainable intensification since the 1990s, crop production in Huantai County of northern China has risen to 15tha(-1)yr(-1) for the annual wheat-maize rotation system. We examined the temporal dynamics of nitrogen (N) budget, N losses, and N use efficiency (NUE) during the 35years (1980-2014) in Huantai. The results revealed that atmospheric N deposition increased 220% while reactive N losses decreased by 21.5% from 1980s to 2010s. During 1980-2002, annual N partial factor productivity (PFPN), apparent NUE and N recovery efficiency (REN) increased from 20.3 to 40.7kggrainkg(-1)Nfert, from 36.5% to 71.0%, and from 32.4% to 57.7%, respectively; meanwhile, reactive N losses intensity, land use intensity and N use intensity decreased by 69.8%, 53.4%, 50.0%, respectively, but without further significant changes after 2002. Overall increases in NUE and decreases in N losses were largely due to the introduction of optimized fertilization practice, mechanization and increased incorporation of crop straw in Huantai. Straw incorporation was also significant in soil N stock accrual and fertility improvement. By 2030, northern China may reach the lowest end of PFPN values in developed countries (>45kggrainkg(-1)Nfert). These agricultural sustainable intensification practices will be critical in maintaining high grain yields and associated decreases in environmental pollution, although water use efficiency in the region still needs to be improved. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. A novel role for the Pol I transcription factor UBTF in maintaining genome stability through the regulation of highly transcribed Pol II genes

    PubMed Central

    Diesch, Jeannine; Lesmana, Analia; Poortinga, Gretchen; Hein, Nadine; Lidgerwood, Grace; Cameron, Donald P.; Ellul, Jason; Goodall, Gregory J.; Wong, Lee H.; Dhillon, Amardeep S.; Hamdane, Nourdine; Rothblum, Lawrence I.; Pearson, Richard B.; Haviv, Izhak; Moss, Tom

    2015-01-01

    Mechanisms to coordinate programs of highly transcribed genes required for cellular homeostasis and growth are unclear. Upstream binding transcription factor (UBTF, also called UBF) is thought to function exclusively in RNA polymerase I (Pol I)-specific transcription of the ribosomal genes. Here, we report that the two isoforms of UBTF (UBTF1/2) are also enriched at highly expressed Pol II-transcribed genes throughout the mouse genome. Further analysis of UBTF1/2 DNA binding in immortalized human epithelial cells and their isogenically matched transformed counterparts reveals an additional repertoire of UBTF1/2-bound genes involved in the regulation of cell cycle checkpoints and DNA damage response. As proof of a functional role for UBTF1/2 in regulating Pol II transcription, we demonstrate that UBTF1/2 is required for recruiting Pol II to the highly transcribed histone gene clusters and for their optimal expression. Intriguingly, lack of UBTF1/2 does not affect chromatin marks or nucleosome density at histone genes. Instead, it results in increased accessibility of the histone promoters and transcribed regions to micrococcal nuclease, implicating UBTF1/2 in mediating DNA accessibility. Unexpectedly, UBTF2, which does not function in Pol I transcription, is sufficient to regulate histone gene expression in the absence of UBTF1. Moreover, depletion of UBTF1/2 and subsequent reduction in histone gene expression is associated with DNA damage and genomic instability independent of Pol I transcription. Thus, we have uncovered a novel role for UBTF1 and UBTF2 in maintaining genome stability through coordinating the expression of highly transcribed Pol I (UBTF1 activity) and Pol II genes (UBTF2 activity). PMID:25452314

  15. Ergonomics Contribution in Maintainability

    NASA Astrophysics Data System (ADS)

    Teymourian, Kiumars; Seneviratne, Dammika; Galar, Diego

    2017-09-01

    The objective of this paper is to describe an ergonomics contribution in maintainability. The economical designs, inputs and training helps to increase the maintainability indicators for industrial devices. This analysis can be helpful, among other cases, to compare systems, to achieve a better design regarding maintainability requirements, to improve this maintainability under specific industrial environment and to foresee maintainability problems due to eventual changes in a device operation conditions. With this purpose, this work first introduces the notion of ergonomics and human factors, maintainability and the implementation of assessment of human postures, including some important postures to perform maintenance activities. A simulation approach is used to identify the critical posture of the maintenance personnel and implements the defined postures with minimal loads on the personnel who use the equipment in a practical scenario. The simulation inputs are given to the designers to improve the workplace/equipment in order to high level of maintainability. Finally, the work concludes summarizing the more significant aspects and suggesting future research.

  16. High Growth Rate Metal-Organic Molecular Beam Epitaxy for the Fabrication of GaAs Space Solar Cells

    NASA Technical Reports Server (NTRS)

    Freundlich, A.; Newman, F.; Monier, C.; Street, S.; Dargan, P.; Levy, M.

    2005-01-01

    In this work it is shown that high quality GaAs photovoltaic devices can be produced by Molecular Beam Epitaxy (MBE) with growth rates comparable to metal-organic chemical vapor deposition (MOCVD) through the subsitution of group III solid sources by metal-organic compounds. The influence the III/V flux-ratio and growth temperatures in maintaining a two dimensional layer by layer growth mode and achieving high growth rates with low residual background impurities is investigated. Finally subsequent to the study of the optimization of n- and p doping of such high growth rate epilayers, results from a preliminary attempt in the fabrication of GaAs photovoltaic devices such as tunnel diodes and solar cells using the proposed high growth rate approach are reported.

  17. Branched-chain Amino Acids are Beneficial to Maintain Growth Performance and Intestinal Immune-related Function in Weaned Piglets Fed Protein Restricted Diet.

    PubMed

    Ren, M; Zhang, S H; Zeng, X F; Liu, H; Qiao, S Y

    2015-12-01

    As a novel approach for disease control and prevention, nutritional modulation of the intestinal health has been proved. However, It is still unknown whether branched-chain amino acid (BCAA) is needed to maintain intestinal immune-related function. The objective of this study was to determine whether BCAA supplementation in protein restricted diet affects growth performance, intestinal barrier function and modulates post-weaning gut disorders. One hundred and eight weaned piglets (7.96±0.26 kg) were randomly fed one of the three diets including a control diet (21% crude protein [CP], CON), a protein restricted diet (17% CP, PR) and a BCAA diet (BCAA supplementation in the PR diet) for 14 d. The growth performance, plasma amino acid concentrations, small intestinal morphology and intestinal immunoglobulins were tested. First, average daily gain (ADG) (p<0.05) and average daily feed intake (ADFI) (p<0.05) of weaned pigs in PR group were lower, while gain:feed ratio was lower than the CON group (p<0.05). Compared with PR group, BCAA group improved ADG (p<0.05), ADFI (p<0.05) and feed:gain ratio (p<0.05) of piglets. The growth performance data between CON and BCAA groups was not different (p>0.05). The PR and BCAA treatments had a higher (p<0.05) plasma concentration of methionine and threonine than the CON treatment. The level of some essential and functional amino acids (such as arginine, phenylalanine, histidine, glutamine etc.) in plasma of the PR group was lower (p<0.05) than that of the CON group. Compared with CON group, BCAA supplementation significantly increased BCAA concentrations (p<0.01) and decreased urea concentration (p<0.01) in pig plasma indicating that the efficiency of dietary nitrogen utilization was increased. Compared with CON group, the small intestine of piglets fed PR diet showed villous atrophy, increasing of intra-epithelial lymphocytes (IELs) number (p<0.05) and declining of the immunoglobulin concentration, including jejunal

  18. Branched-chain Amino Acids are Beneficial to Maintain Growth Performance and Intestinal Immune-related Function in Weaned Piglets Fed Protein Restricted Diet

    PubMed Central

    Ren, M.; Zhang, S. H.; Zeng, X. F.; Liu, H.; Qiao, S. Y.

    2015-01-01

    As a novel approach for disease control and prevention, nutritional modulation of the intestinal health has been proved. However, It is still unknown whether branched-chain amino acid (BCAA) is needed to maintain intestinal immune-related function. The objective of this study was to determine whether BCAA supplementation in protein restricted diet affects growth performance, intestinal barrier function and modulates post-weaning gut disorders. One hundred and eight weaned piglets (7.96±0.26 kg) were randomly fed one of the three diets including a control diet (21% crude protein [CP], CON), a protein restricted diet (17% CP, PR) and a BCAA diet (BCAA supplementation in the PR diet) for 14 d. The growth performance, plasma amino acid concentrations, small intestinal morphology and intestinal immunoglobulins were tested. First, average daily gain (ADG) (p<0.05) and average daily feed intake (ADFI) (p<0.05) of weaned pigs in PR group were lower, while gain:feed ratio was lower than the CON group (p<0.05). Compared with PR group, BCAA group improved ADG (p<0.05), ADFI (p<0.05) and feed:gain ratio (p<0.05) of piglets. The growth performance data between CON and BCAA groups was not different (p>0.05). The PR and BCAA treatments had a higher (p<0.05) plasma concentration of methionine and threonine than the CON treatment. The level of some essential and functional amino acids (such as arginine, phenylalanine, histidine, glutamine etc.) in plasma of the PR group was lower (p<0.05) than that of the CON group. Compared with CON group, BCAA supplementation significantly increased BCAA concentrations (p<0.01) and decreased urea concentration (p<0.01) in pig plasma indicating that the efficiency of dietary nitrogen utilization was increased. Compared with CON group, the small intestine of piglets fed PR diet showed villous atrophy, increasing of intra-epithelial lymphocytes (IELs) number (p<0.05) and declining of the immunoglobulin concentration, including jejunal

  19. An in vitro biofilm model system maintaining a highly reproducible species and metabolic diversity approaching that of the human oral microbiome

    PubMed Central

    2013-01-01

    Background Our knowledge of microbial diversity in the human oral cavity has vastly expanded during the last two decades of research. However, much of what is known about the behavior of oral species to date derives from pure culture approaches and the studies combining several cultivated species, which likely does not fully reflect their function in complex microbial communities. It has been shown in studies with a limited number of cultivated species that early oral biofilm development occurs in a successional manner and that continuous low pH can lead to an enrichment of aciduric species. Observations that in vitro grown plaque biofilm microcosms can maintain similar pH profiles in response to carbohydrate addition as plaque in vivo suggests a complex microbial community can be established in the laboratory. In light of this, our primary goal was to develop a robust in vitro biofilm-model system from a pooled saliva inoculum in order to study the stability, reproducibility, and development of the oral microbiome, and its dynamic response to environmental changes from the community to the molecular level. Results Comparative metagenomic analyses confirmed a high similarity of metabolic potential in biofilms to recently available oral metagenomes from healthy subjects as part of the Human Microbiome Project. A time-series metagenomic analysis of the taxonomic community composition in biofilms revealed that the proportions of major species at 3 hours of growth are maintained during 48 hours of biofilm development. By employing deep pyrosequencing of the 16S rRNA gene to investigate this biofilm model with regards to bacterial taxonomic diversity, we show a high reproducibility of the taxonomic carriage and proportions between: 1) individual biofilm samples; 2) biofilm batches grown at different dates; 3) DNA extraction techniques and 4) research laboratories. Conclusions Our study demonstrates that we now have the capability to grow stable oral microbial in vitro

  20. Highly oriented graphene growth and characterization

    NASA Astrophysics Data System (ADS)

    Saheed, Mohamed Salleh Mohamed; Mohamed, Norani Muti; Singh, Balbir Singh Mahinder; Saheed, Mohamed Shuaib Mohamed

    2016-11-01

    Combination of the highly ordered monolayers to form the multilayer interconnected graphene is essential to produce robust and free standing graphene unlike its counterpart 2D monolayers. Here, chemical vapor deposition (CVD) technique is employed to produce highly flexible and high mobility 3D graphene. In this study, the 3D graphene is grown via direct carbon deposition on sacrificial template. With the use of polymer coating such as poly methyl methacrylate (PMMA), it is observed that the graphene is bendable without any degradation. Great potential in term of electrical conductivity and flexibility can be exploited for future work for this CVD grown 3D graphene.

  1. Surface growth of MG(multilayer graphene)-SiC nanofillers/poly(vinylidene fluoride) composites for improving thermal conductivity and maintaining electrical insulation

    NASA Astrophysics Data System (ADS)

    He, Jing; Guo, Yulan; Tian, Konghu; Wang, Hua; Su, Zheng; Huang, Weiqi; Tian, Xingyou

    2017-08-01

    In the present research, a high-frequency heating process with the advantages of simplicity and high yield was applied to synthesize multilayer graphene-SiC nanofillers (MG-SiCnf) and found to boost yields dramatically. The growth process of MG-SiCnf was also investigated. Nanofillers grown on an MG surface consisted of both SiC particles and SiC nanofibers. Interestingly, the growth process of SiC nanofibers included two main steps: firstly, SiC particles gathered on the edge of the MG, and then they grew into SiC nanofibers. SiC nanofibers enhanced the thermal conductivity of materials whereas SiC particles tended to hinder electronic transmission. The vertical and in-plane orientated thermal conductivities of poly(vinylidene fluoride) (PVDF)/MG-SiCnf composites were determined to be 0.28 and 30.491 W m-1 K-1, while the maximum value of the electrical conductivity of PVDF/MG-SiCnf composites was only 2.0  ×  10-11 S cm-1. In addition, the storage modulus of PVDF/MG-SiCnf composites also improved remarkably in comparison with that of pure PVDF.

  2. Polarization Maintaining, Very-Large-Mode Area, Er Fiber Amplifier for High Energy Pulses at 1572.3 nm

    NASA Technical Reports Server (NTRS)

    Nicholoson, J. W.; DeSantolo, A.; Yan, M. F.; Wisk, P.; Mangan, B.; Puc, G.; Yu, A.; Stephen, M.

    2016-01-01

    We demonstrate the first polarization maintaining, very-large-mode-area Er-doped fiber amplifier with 1000 square micron effective area. The amplifier is core pumped by a Raman fiber laser and is used to generate single frequency one microsecond pulses with pulse energy of 368 microJoules, M2 of 1.1, and polarization extinction greater than 20 dB. The amplifier operates at 1572.3 nm, a wavelength useful for trace atmospheric CO2 detection.

  3. "Personal Growth: A Continuation High School Drug Defense."

    ERIC Educational Resources Information Center

    Preshaw, Gene; Steele, Larry

    Two drug intervention courses were developed for students at risk, entitled "Personal Growth" and "Advanced Personal Growth." These courses were implemented by continuation high school staffs to raise self-esteem. Both courses emphasize building positive relationships and support systems, sharing feelings, and trusting. These are skills students…

  4. Measuring Junior High Math Growth in the NCLB Environment.

    ERIC Educational Resources Information Center

    Flicek, Michael

    2003-01-01

    Examines the implementation and utility of the blocked longitudinal growth method (BLGM) to understand math course placement practices in junior high schools in one district. Found that movement away from a conventional and normative approach to a more flexible approach based on growth in math skills seems to be supported. (Author/MLF)

  5. High Temperature Protonic Conductors by Melt Growth

    DTIC Science & Technology

    2006-11-21

    produce a family of single crystal and multiphase materials that exhibit high temperature protonic conductance, and superior mechanical properties at...with x = 0.05, 0.2, were ball-milled (WC ball and bottle) for 5 min. The resulting slurry was then dried at 70 ºC. The dried powders were heated 1000...explained taking into account the redistribution of the intercellular amorphous phase, and assuming that viscous flow plays a role at low strains. To

  6. Listeria monocytogenes varies among strains to maintain intracellular pH homeostasis under stresses by different acids as analyzed by a high-throughput microplate-based fluorometry

    PubMed Central

    Cheng, Changyong; Yang, Yongchun; Dong, Zhimei; Wang, Xiaowen; Fang, Chun; Yang, Menghua; Sun, Jing; Xiao, Liya; Fang, Weihuan; Song, Houhui

    2015-01-01

    Listeria monocytogenes, a food-borne pathogen, has the capacity to maintain intracellular pH (pHi) homeostasis in acidic environments, but the underlying mechanisms remain elusive. Here, we report a simple microplate-based fluorescent method to determine pHi of listerial cells that were prelabeled with the fluorescent dye carboxyfluorescein diacetate N-succinimidyl ester and subjected to acid stress. We found that L. monocytogenes responds differently among strains toward organic and inorganic acids to maintain pHi homeostasis. The capacity of L. monocytogenes to maintain pHi at extracellular pH 4.5 (pHex) was compromised in the presence of acetic acid and lactic acid, but not by hydrochloric acid and citric acid. Organic acids exhibited more inhibitory effects than hydrochloric acid at certain pH conditions. Furthermore, the virulent stains L. monocytogenes EGDe, 850658 and 10403S was more resistant to acidic stress than the avirulent M7 which showed a defect in maintaining pHi homeostasis. Deletion of sigB, a stress-responsive alternative sigma factor from 10403S, markedly altered intracellular pHi homeostasis, and showed a significant growth and survival defect under acidic conditions. Thus, this work provides new insights into bacterial survival mechanism to acidic stresses. PMID:25667585

  7. Listeria monocytogenes varies among strains to maintain intracellular pH homeostasis under stresses by different acids as analyzed by a high-throughput microplate-based fluorometry.

    PubMed

    Cheng, Changyong; Yang, Yongchun; Dong, Zhimei; Wang, Xiaowen; Fang, Chun; Yang, Menghua; Sun, Jing; Xiao, Liya; Fang, Weihuan; Song, Houhui

    2015-01-01

    Listeria monocytogenes, a food-borne pathogen, has the capacity to maintain intracellular pH (pHi) homeostasis in acidic environments, but the underlying mechanisms remain elusive. Here, we report a simple microplate-based fluorescent method to determine pHi of listerial cells that were prelabeled with the fluorescent dye carboxyfluorescein diacetate N-succinimidyl ester and subjected to acid stress. We found that L. monocytogenes responds differently among strains toward organic and inorganic acids to maintain pHi homeostasis. The capacity of L. monocytogenes to maintain pHi at extracellular pH 4.5 (pHex) was compromised in the presence of acetic acid and lactic acid, but not by hydrochloric acid and citric acid. Organic acids exhibited more inhibitory effects than hydrochloric acid at certain pH conditions. Furthermore, the virulent stains L. monocytogenes EGDe, 850658 and 10403S was more resistant to acidic stress than the avirulent M7 which showed a defect in maintaining pHi homeostasis. Deletion of sigB, a stress-responsive alternative sigma factor from 10403S, markedly altered intracellular pHi homeostasis, and showed a significant growth and survival defect under acidic conditions. Thus, this work provides new insights into bacterial survival mechanism to acidic stresses.

  8. Soybean stem growth under high-pressure sodium with supplemental blue lighting

    NASA Technical Reports Server (NTRS)

    Wheeler, R. M.; Mackowiak, C. L.; Sager, J. C.

    1991-01-01

    To study high-pressure sodium (HPS) lamps used for plant lighting because of their high energy conversion efficiencies, 'McCall' soybean plants were grown for 28 days in growth chambers utilizing HPS lamps, with/without supplemental light from blue phosphor fluorescent lamps. Total photosynthetic photon flux levels, including blue fluorescent, were maintained near 300 or 500 micromol/sq m s. Results indicate that employment of HPS or other blue-deficient sources for lighting at low to moderate photosynthetic photon flux levels may cause abnormal stem elongation, but this can be prevented by the addition of a small amount of supplemental blue light.

  9. Soybean stem growth under high-pressure sodium with supplemental blue lighting

    NASA Technical Reports Server (NTRS)

    Wheeler, R. M.; Mackowiak, C. L.; Sager, J. C.

    1991-01-01

    To study high-pressure sodium (HPS) lamps used for plant lighting because of their high energy conversion efficiencies, 'McCall' soybean plants were grown for 28 days in growth chambers utilizing HPS lamps, with/without supplemental light from blue phosphor fluorescent lamps. Total photosynthetic photon flux levels, including blue fluorescent, were maintained near 300 or 500 micromol/sq m s. Results indicate that employment of HPS or other blue-deficient sources for lighting at low to moderate photosynthetic photon flux levels may cause abnormal stem elongation, but this can be prevented by the addition of a small amount of supplemental blue light.

  10. High-thermal-gradient Superalloy Crystal Growth

    NASA Technical Reports Server (NTRS)

    Pearson, D. D.; Anton, D. L.; Giamei, A. F.

    1985-01-01

    Single, (001)-oriented crystals of PWA 1480 were processed in alumina/silica shell molds in a laboratory high gradient furnace. The furnace employs a graphite resistance heated element, a radiation baffle, and a water cooled radiation trap below the baffle. All crystals were grown in vacuum (10 torr) and all heat transfer was radiative. The element is constructed with a variable cross section that is tapered just above the baffle to maximize heat input and therefore thermal gradient. A maximum alloy temperature of 1600 C was used. A thermal gradient of 130 deg C/cm was recorded at 1370 C just above the solidus of the PWA 1480 alloys. Crystal bars with 14.4 and 17.5 mm diameters were grown in alumina/silica shell molds. Each crystal was started from a 1.6 mm pencil seed at a rate of 76 mm/hr and slowly accelerated to a rate of 200 mm/hr under computer control. Volume percent porosity and average pore size were measured as functions of distance in representative bars. Low cycle fatigue behavior and stress rupture properties were determined.

  11. High-throughput phenotyping of root growth dynamics.

    PubMed

    Yazdanbakhsh, Nima; Fisahn, Joachim

    2012-01-01

    Plant organ phenotyping by noninvasive video imaging techniques provides a powerful tool to assess physiological traits, circadian and diurnal rhythms, and biomass production. In particular, growth of individual plant organs is known to exhibit a high plasticity and occurs as a result of the interaction between various endogenous and environmental processes. Thus, any investigation aiming to unravel mechanisms that determine plant or organ growth has to accurately control and document the environmental growth conditions. Here we describe challenges in establishing a recently developed plant root monitoring platform (PlaRoM) specially suited for noninvasive high-throughput plant growth analysis with highest emphasis on the detailed documentation of capture time, as well as light and temperature conditions. Furthermore, we discuss the experimental procedure for measuring root elongation kinetics and key points that must be considered in such measurements. PlaRoM consists of a robotized imaging platform enclosed in a custom designed phytochamber and a root extension profiling software application. This platform has been developed for multi-parallel recordings of root growth phenotypes of up to 50 individual seedlings over several days, with high spatial and temporal resolution. Two Petri dishes are mounted on a vertical sample stage in a custom designed phytochamber that provides exact temperature control. A computer-controlled positioning unit moves these Petri dishes in small increments and enables continuous screening of the surface under a binocular microscope. Detection of the root tip is achieved by applying thresholds on image pixel data and verifying the neighbourhood for each dark pixel. The growth parameters are visualized as position over time or growth rate over time graphs and averaged over consecutive days, light-dark periods and 24 h day periods. This setup enables the investigation of root extension profiles of different genotypes in various growth

  12. Improvement of electrical conductivity while maintaining a high-transmittance of graphene oxide/MWCNT film by hydrazine reduction.

    PubMed

    Mihara, Shota; Tsubota, Toshiki; Murakami, Naoya; Ohno, Teruhisa

    2012-09-01

    In this study, we attempted to synthesize a transparent electrode with a composite of along graphene with multi-walled carbon nanotubes (MWCNT). Hydrazine was used for the reduction process. After the treatment with hydrazine, the sheet resistance was reduced from over 10 Momega/sq. The longest dip time sample (reduced GO/MWCNT-5, RGO/MWCNT-5) had the lowest sheet resistance (114 komega/sq). The reason for this decrease is likely due to the fact that the concentration of MWCNT in the deposited film increased with increases in the deposition time based on the higher density of the MWCNT. Although the transmittance decreased with decreases in the sheet resistance, the transmittances of all the samples were approximately 80% at 550 nm. We succeed in synthesizing a film that maintains transmittance (80%) despite a decreasing sheet resistance.

  13. Effects of Tamoxifen and oestrogen on histology and radiographic density in high and low mammographic density human breast tissues maintained in murine tissue engineering chambers.

    PubMed

    Chew, G L; Huo, C W; Huang, D; Blick, T; Hill, P; Cawson, J; Frazer, H; Southey, M C; Hopper, J L; Britt, K; Henderson, M A; Haviv, I; Thompson, E W

    2014-11-01

    Mammographic density (MD) is a strong risk factor for breast cancer. It is altered by exogenous endocrine treatments, including hormone replacement therapy and Tamoxifen. Such agents also modify breast cancer (BC) risk. However, the biomolecular basis of how systemic endocrine therapy modifies MD and MD-associated BC risk is poorly understood. This study aims to determine whether our xenograft biochamber model can be used to study the effectiveness of therapies aimed at modulating MD, by examine the effects of Tamoxifen and oestrogen on histologic and radiographic changes in high and low MD tissues maintained within the biochamber model. High and low MD human tissues were precisely sampled under radiographic guidance from prophylactic mastectomy fresh specimens of high-risk women, then inserted into separate vascularized murine biochambers. The murine hosts were concurrently implanted with Tamoxifen, oestrogen or placebo pellets, and the high and low MD biochamber tissues maintained in the murine host environment for 3 months, before the high and low MD biochamber tissues were harvested for histologic and radiographic analyses. The radiographic density of high MD tissue maintained in murine biochambers was decreased in Tamoxifen-treated mice compared to oestrogen-treated mice (p = 0.02). Tamoxifen treatment of high MD tissue in SCID mice led to a decrease in stromal (p = 0.009), and an increase in adipose (p = 0.023) percent areas, compared to placebo-treated mice. No histologic or radiographic differences were observed in low MD biochamber tissue with any treatment. High MD biochamber tissues maintained in mice implanted with Tamoxifen, oestrogen or placebo pellets had dynamic and measurable histologic compositional and radiographic changes. This further validates the dynamic nature of the MD xenograft model, and suggests the biochamber model may be useful for assessing the underlying molecular pathways of Tamoxifen-reduced MD, and in testing of other

  14. A key role for early growth response-1 and nuclear factor-kappaB in mediating and maintaining GRO/CXCR2 proliferative signaling in esophageal cancer.

    PubMed

    Wang, Bo; Khachigian, Levon M; Esau, Luke; Birrer, Michael J; Zhao, Xiaohang; Parker, M Iqbal; Hendricks, Denver T

    2009-05-01

    Although early growth response-1 (EGR-1) has been shown as a key transcription factor in controlling cell growth, proliferation, differentiation, and angiogenesis, its role in the development of esophageal cancer is poorly understood despite the high frequency of this disease in many parts of the world. Here, immunohistochemistry showed that EGR-1 is overexpressed in 80% of esophageal tumor tissues examined. Furthermore, EGR-1 is constitutively expressed in all esophageal cancer cell lines analyzed. Esophageal squamous carcinoma WHCO1 cells stably transfected with EGR-1 short hairpin RNA displayed a 55% reduction in EGR-1 protein levels, 50% reduction in cell proliferation, a 50% reduction in cyclin-dependent kinase 4 levels, and a 2-fold induction in p27(Kip1) levels associated with a G(2)-M cell cycle arrest. EGR-1 knockdown also caused a marked induction in IkappaBalpha expression, an effect also observed in GRObeta RNA interference-expressing WHCO1 cells, because EGR-1 lies downstream of GRO/CXCR2 signaling. Furthermore, p65 mRNA levels were also reduced in cells treated with either short hairpin RNA EGR-1 or small interfering RNA EGR-1. Immunohistochemical analysis indicated that p65 is elevated in 78% (n = 61) of esophageal tumor sections analyzed. Moreover, nuclear factor-kappaB inhibition with either sodium salicylate or p65 RNA interference led to a significant reduction in GROalpha and GRObeta expression. These results indicate that EGR-1 and nuclear factor-kappaB mediate GRO/CXCR2 proliferative signaling in esophageal cancer and may represent potential target molecules for therapeutic intervention.

  15. Growth of highly versus moderately trained competitive female artistic gymnasts.

    PubMed

    Daly, Robin M; Caine, Dennis; Bass, Shona L; Pieter, Willy; Broekhoff, Jan

    2005-06-01

    To investigate whether growth was adversely affected in 137 young competitive female artistic gymnasts involved in different training volumes. This was a 2-yr prospective cohort study in which height, sitting height, leg length, weight, skinfolds, and pubertal status were measured in competitive advanced (20-27 h x wk(-1)) and intermediate (7.5-22 h x wk(-1)) training level female gymnasts every 6-12 months. Biological parameters of the adolescent growth curve were estimated using the Preece-Baines growth model. Growth rates were estimated for both groups from the mixed-longitudinal data. Estimated ages at peak height velocity (PHV) (13-13.5 yr) and mean PHV (6.2-6.4 cm x yr(-1)) for the advanced- and intermediate-level gymnasts suggest that these gymnasts were later maturing and experienced a blunting of the growth spurt relative to reference values for U.S. youth. Comparison of growth velocities by pubertal status revealed that height velocity was lower in the advanced- versus the intermediate-level peripubertal gymnasts, which was due to a significant reduction in sitting height velocity (2.3 vs 3.1 cm x yr(-1), P. < 0.05). No marked acceleration in height or sitting height velocity was detected in the advanced-level gymnasts from pre- to peripuberty. Inspection of individual growth rates revealed that over 35% of the pre- and peripubertal gymnasts experienced growth faltering (height velocity less than 4.5 cm x yr(-1)) during follow-up. Advanced-and intermediate-training level competitive female gymnasts tend to exhibit an adolescent growth spurt that is similar in timing and tempo to short, normal, slowly maturing girls, but the high frequency of growth faltering suggests that training may alter the tempo of growth and maturation in some, but not all, female gymnasts.

  16. Growth and nutritional status of Tibetan children at high altitude.

    PubMed

    Argnani, Lisa; Cogo, Annalisa; Gualdi-Russo, Emanuela

    2008-09-01

    Growth and development are clearly affected by high-altitude exposure to hypoxia, nutritional stress, cold or a combination of these factors. Very little research has been conducted on the growth and nutritional status of children living on the Tibetan Plateau. The present study evaluated the environmental impact on human growth by analyzing anthropometric characteristics of Tibetan children aged 8-14, born and raised above 4000 m altitude on the Himalayan massif in the prefecture of Shegar in Tibet Autonomous Region. Data on anthropometric traits, never measured in this population, were collected and the nutritional status was assessed. A reference data set is provided for this population. There was no evidence of wasting but stunting was detected (28.3%). Children permanently exposed to the high-altitude environment above 4000 m present a phenotypic form of adaptation and a moderate reduction in linear growth. However, it is also necessary to consider the effects of socioeconomic deprivation.

  17. Synthesis and Characterization of High-Purity Bismuth Nanowires via Seed-Assisted Growth Approach

    NASA Astrophysics Data System (ADS)

    Mu, Xin; Zhao, Wen-Yu; He, Dan-Qi; Zhou, Hong-Yu; Zhu, Wan-Ting; Zhang, Qing-Jie

    2015-06-01

    Nanowires are considered as high-performance thermoelectric materials with large Seebeck coefficients due to quantum confinement and low thermal conductivity because of enhanced boundary scattering of phonons. In this work, a seed-assisted growth method has been developed to synthesize high-purity bismuth nanowires. The bismuth seeds were first synthesized by reducing BiCl3 in the ice water with NaBH4. The high-purity bismuth nanowires about 40-50 nm in diameter and several tens of micrometers in length were then grown on bismuth seeds by reducing NaBiO3 with ethylene glycol. X-ray diffraction, scanning electron microscopy, and transmission electron microscopy were employed to characterize the crystal structure, microstructure, and growth direction of the bismuth seeds and nanowires. The effects of temperature, reductant, and bismuth seeds template on the microstructures of the bismuth nanowires were also investigated. The synthesis conditions of bismuth seeds and nanowires were optimized. The selected area electron diffraction pattern confirms that the growth direction of bismuth nanowires is parallel to [] direction. It was discovered that high-purity bismuth nanowires with high aspect ratio can be synthesized by precisely controlling the temperature to adjust the nucleation rate of the bismuth nuclei, selecting the appropriate reductant to maintain a low nucleation rate, and using bismuth seeds as the template of the epitaxial growth of the bismuth nuclei.

  18. Will intra-specific differences in transpiration efficiency in wheat be maintained in a high CO₂ world? A FACE study.

    PubMed

    Tausz-Posch, Sabine; Norton, Robert M; Seneweera, Saman; Fitzgerald, Glenn J; Tausz, Michael

    2013-06-01

    This study evaluates whether the target breeding trait of superior leaf level transpiration efficiency is still appropriate under increasing carbon dioxide levels of a future climate using a semi-arid cropping system as a model. Specifically, we investigated whether physiological traits governing leaf level transpiration efficiency, such as net assimilation rates (A(net)), stomatal conductance (g(s)) or stomatal sensitivity were affected differently between two Triticum aestivum L. cultivars differing in transpiration efficiency (cv. Drysdale, superior; cv. Hartog, low). Plants were grown under Free Air Carbon dioxide Enrichment (FACE, approximately 550 µmol mol⁻¹ or ambient CO₂ concentrations (approximately 390 µmol mol⁻¹). Mean A(net) (approximately 15% increase) and gs (approximately 25% decrease) were less affected by elevated [CO₂] than previously found in FACE-grown wheat (approximately 25% increase and approximately 32% decrease, respectively), potentially reflecting growth in a dry-land cropping system. In contrast to previous FACE studies, analyses of the Ball et al. model revealed an elevated [CO₂] effect on the slope of the linear regression by 12% indicating a decrease in stomatal sensitivity to the combination of [CO₂], photosynthesis rate and humidity. Differences between cultivars indicated greater transpiration efficiency for Drysdale with growth under elevated [CO₂] potentially increasing the response of this trait. This knowledge adds valuable information for crop germplasm improvement for future climates.

  19. High-pressure processing of a raw milk cheese improved its food safety maintaining the sensory quality.

    PubMed

    Delgado, Francisco José; Delgado, Jonathan; González-Crespo, José; Cava, Ramón; Ramírez, Rosario

    2013-12-01

    The effect of high-pressure treatment (400 or 600 MPa for 7 min) on microbiology, proteolysis, texture and sensory parameters was investigated in a mature raw goat milk cheese. At day 60 of analysis, Mesophilic aerobic, Enterobacteriaceae, lactic acid bacteria and Listeria spp. were inactivated after high-pressure treatment at 400 or 600 MPa. At day 90, mesophilic aerobic, lactic acid bacteria and Micrococacceae counts were significantly lower in high-pressure-treated cheeses than in control ones. In general, nitrogen fractions were significantly modified after high-pressure treatment on day 60 at 600 MPa compared with control cheeses, but this effect was not found in cheeses after 30 days of storage (day 90). On the other hand, high-pressure treatment caused a significant increase of some texture parameters. However, sensory analysis showed that neither trained panellists nor consumers found significant differences between control and high-pressure-treated cheeses.

  20. Accountability Strain, College Readiness Drain: Sociopolitical Tensions Involved in Maintaining a College-Going Culture in a High "Minority", High Poverty, Texas High School

    ERIC Educational Resources Information Center

    Welton, Anjale; Williams, Montrischa

    2015-01-01

    Currently school reform discourse encourages states to adopt college readiness standards. Meanwhile, federal and state accountability and related mandated reforms remain a policy concern. As such, it is important to examine the interplay between accountability and the establishment of a college-going culture in high "minority", high…

  1. Soy protein isolate inhibits high fat diet-induced senescence pathways in osteoblasts to maintain bone acquisition in rats

    USDA-ARS?s Scientific Manuscript database

    Chronic consumption by experimental animals of a typical Western diet high in saturated fats and cholesterol during postnatal life has been demonstrated to impair skeletal development. However, the underlying mechanism by which high fat, energy dense diets affect bone-forming cell phenotypes is poor...

  2. Possible burst-like facet growth mode at high temperatures

    NASA Astrophysics Data System (ADS)

    Lovrić, Davorin; Vučić, Zlatko; Gladić, Jadranko

    2008-07-01

    A decade ago, a burst-like growth mode of c-facets of 4He crystals growing at mK temperatures, characterized by the alternation of time intervals during which the facet does not advance with the intervals of its fast advancement, was found [J.P. Ruutu, P.J. Hakonen, A.V. Babkin, A.Y. Parshin, J.S. Penttilä, J.P. Saramäki, G. Tvalashvili, Phys. Rev. Lett. 76 (1996) 4187]. We investigate the possibility that a similar facet growth mode exists for facets at high growth temperatures. We have applied the digital laser interferometry for monitoring facet kinetics of spherical copper selenide single crystals during their growth at constant volume growth rate around 800 K. Our analysis of directly measured (1 1 1) facet advancement curves has revealed that they consist of time intervals during which the facet does not advance vertically alternating with the time intervals of enhanced growth, resembling the burst-like facet growth mode. The results are discussed in terms of the enhancement of the local supersaturation induced by the existence of nucleation barrier.

  3. High Temperature Fatigue Crack Growth Behavior of Alloy 10

    NASA Technical Reports Server (NTRS)

    Gayda, John

    2001-01-01

    Methods to improve the high temperature, dwell crack growth resistance of Alloy 10, a high strength, nickel-base disk alloy, were studied. Two approaches, heat treat variations and composition modifications, were investigated. Under the heat treat approach, solution temperature, cooling rates, and stabilization, were studied. It was found that higher solution temperatures, which promote coarser grain sizes, coupled with a 1550 F stabilization treatment were found to significantly reduce dwell crack growth rates at 1300 F Changes in the niobium and tantalum content were found to have a much smaller impact on crack growth behavior. Lowering the niobium:tantalum ratio did improve crack growth resistance and this effect was most pronounced for coarse grain microstructures. Based on these findings, a coarse grain microstructure for Alloy 10 appears to be the best option for improving dwell crack growth resistance, especially in the rim of a disk where temperatures can reach or exceed 1300 T. Further, the use of advanced processing technologies, which can produce a coarse grain rim and fine grain bore, would be the preferred option for Alloy 10 to obtain the optimal balance between tensile, creep, and crack growth requirements for small gas turbine engines.

  4. Dolutegravir-based monotherapy or dual therapy maintains a high proportion of viral suppression even in highly experienced HIV-1-infected patients.

    PubMed

    Gubavu, Camelia; Prazuck, Thierry; Niang, Mohamadou; Buret, Jennifer; Mille, Catherine; Guinard, Jérôme; Avettand-Fènoël, Véronique; Hocqueloux, Laurent

    2016-04-01

    Dolutegravir is a powerful, well-tolerated integrase inhibitor with a high genetic barrier to resistance and may thus constitute the backbone of lightened regimens. This was a monocentric, retrospective study. HIV-1-infected patients receiving dolutegravir as monotherapy (mDGV) or dual therapy (dDGV) were systematically identified. The primary outcome was the proportion of patients who maintained undetectable (<50 copies/mL) plasma HIV RNA [plasma viral load (PVL)]. We identified 21 patients on mDGV (50 mg/day) and 31 on dDGV (50 or 100 mg/day, with atazanavir  ±  ritonavir, n = 12; rilpivirine, n = 11; maraviroc, n = 3; lamivudine, n = 3; darunavir/ritonavir, n = 1; or abacavir, n = 1). All of the patients were treatment experienced and 48% had experienced at least one virological failure. The baseline characteristics were as follows (for the mDGV/dDGV patients, respectively): 5%/29% had a history of AIDS; the median (IQR) highest PVL was 4.5 (4.3-5.5)/5.3 (4.7-5.6) log copies/mL; the median (IQR) nadir CD4+ count was 310 (280-468)/199 (134-281) cells/mm(3); 100% had undetectable PVL before the mDGV for a median (IQR) duration of 5.9 (3.5-9.9) years/81% had undetectable PVL before the dDGV for a median (IQR) duration of 3.7 (1.4-8.3) years; and the median (IQR) HIV DNA level was 2.7 (2.1-3.1)/2.9 (2.7-3) log copies/10(6) PBMCs. At the last follow-up visit, 100% and 97% of patients showed undetectable PVL following mDGV and dDGV, respectively [median (IQR) follow-up of 32 (29-45) and 50 (30-74) weeks, respectively]. In our experience, dolutegravir-based lightened regimens provided a high proportion of viral suppression, even in highly treatment-experienced patients. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy.

  5. Dolutegravir-based monotherapy or dual therapy maintains a high proportion of viral suppression even in highly experienced HIV-1-infected patients

    PubMed Central

    Gubavu, Camelia; Prazuck, Thierry; Niang, Mohamadou; Buret, Jennifer; Mille, Catherine; Guinard, Jérôme; Avettand-Fènoël, Véronique; Hocqueloux, Laurent

    2016-01-01

    Background Dolutegravir is a powerful, well-tolerated integrase inhibitor with a high genetic barrier to resistance and may thus constitute the backbone of lightened regimens. Methods This was a monocentric, retrospective study. HIV-1-infected patients receiving dolutegravir as monotherapy (mDGV) or dual therapy (dDGV) were systematically identified. The primary outcome was the proportion of patients who maintained undetectable (<50 copies/mL) plasma HIV RNA [plasma viral load (PVL)]. Results We identified 21 patients on mDGV (50 mg/day) and 31 on dDGV (50 or 100 mg/day, with atazanavir ± ritonavir, n = 12; rilpivirine, n = 11; maraviroc, n = 3; lamivudine, n = 3; darunavir/ritonavir, n = 1; or abacavir, n = 1). All of the patients were treatment experienced and 48% had experienced at least one virological failure. The baseline characteristics were as follows (for the mDGV/dDGV patients, respectively): 5%/29% had a history of AIDS; the median (IQR) highest PVL was 4.5 (4.3–5.5)/5.3 (4.7–5.6) log copies/mL; the median (IQR) nadir CD4+ count was 310 (280–468)/199 (134–281) cells/mm3; 100% had undetectable PVL before the mDGV for a median (IQR) duration of 5.9 (3.5–9.9) years/81% had undetectable PVL before the dDGV for a median (IQR) duration of 3.7 (1.4–8.3) years; and the median (IQR) HIV DNA level was 2.7 (2.1–3.1)/2.9 (2.7–3) log copies/106 PBMCs. At the last follow-up visit, 100% and 97% of patients showed undetectable PVL following mDGV and dDGV, respectively [median (IQR) follow-up of 32 (29–45) and 50 (30–74) weeks, respectively]. Conclusions In our experience, dolutegravir-based lightened regimens provided a high proportion of viral suppression, even in highly treatment-experienced patients. PMID:26712907

  6. Acidic pH with coordinated reduction of basic fibroblast growth factor maintains the glioblastoma stem cell-like phenotype in vitro.

    PubMed

    Haley, Elizabeth M; Tilson, Samantha G; Triantafillu, Ursula L; Magrath, Justin W; Kim, Yonghyun

    2017-01-04

    Glioblastoma stem cells (GSCs) are a unique subpopulation of cells within glioblastoma multiforme (GBM) brain tumors that possess the ability to self-renew and differentiate into bulk tumor cells. GSCs are resistant to currently available treatments and are the likely culprit behind tumor relapse in GBM patients. However, GSCs are currently inaccessible to the larger scientific community because obtaining a sufficient number of GSCs remains technically challenging and cost-prohibitive. Thus, the objective of this study was to develop a more efficient GSC culture strategy that results in a higher cell yield of GSCs at a lower cost. We observed that the basic fibroblast growth factor (bFGF) is indispensable in allowing GSCs to retain an optimal stem cell-like phenotype in vitro, but little change was seen in their stemness when grown with lower concentrations of bFGF than the established protocol. Interestingly, a dynamic fluctuation of GSC protein marker expression was observed that corresponded to the changes in the bFGF concentration during the culture period. This suggested that bFGF alone did not control stem cell-like phenotype; rather, it was linked to the fluctuations of both bFGF and media pH. We demonstrated that a high level of stem cell-like phenotype could be retained even when lowering bFGF to 8 ng/mL when the media pH was simultaneously lowered to 6.8. These results provide the proof-of-concept that GSC expansion costs could be lowered to a more economical level and warrant the use of pH- and bFGF-controlled bioprocessing methodologies to more optimally expand GSCs in the future.

  7. Education methods for maintaining nursing competency in low-volume, high-risk procedures in the rural setting: bridging the theory to practice gap.

    PubMed

    Banks, Cassie M; Gilmartin, Heather; Fink, Regina M

    2010-01-01

    Nurses practicing in the rural setting have faced a unique challenge in maintaining competency in low-volume, high-risk procedures. This study assessed the effectiveness of a focused, multifaceted educational intervention on the retention of nursing knowledge related to central venous access devices care and maintenance. A pretest-posttest intervention study design was used at a 58-bed rural healthcare facility in a Western state. This study demonstrates a statistically significant increase in functional nursing knowledge in the postintervention period.

  8. Nucleation and growth kinetics of biochemicals measured at high supersaturations

    NASA Astrophysics Data System (ADS)

    Mahajan, Amarjit J.; Kirwan, Donald J.

    1994-12-01

    A grid mixer device (characteristic micromixing time < 3 ms) was successfully used to measure both nucleation and growth kinetics of lovastatin in 60 vol% methanol and asparagine monohydrate in 50 vol% 2-propanol at 23°C at high supersaturations but in the absence of mixing limitations. The supersaturation ratios investigated were in the range 1.25-8.8 for the lovastatin system and 1.17-4.1 for the asparagine system. When plotted according to primary nucleation theory, the induction time and nucleation rate measurements for both systems exhibited a homogeneous nucleation region at high supersaturations and a heterogeneous nucleation region at low supersaturations. The values of interfacial free energy extracted from these measurements for lovastatin (1.4-1.6 mJ/m 2) and asparagine (4.5-6.1 mJ/m 2) were an order-of-magnitude lower than those for inorganic salts reflecting the weaker intermolecular bonding in such biochemical solutes. The measured crystal growth rates for both solutes over the entire range of supersaturation could be represented with a power law dependence on chemical potential driving force. The kinetic orders of crystal growth were found to be 6.7 and 2.9 for lovastatin and asparagine, respectively. These unusually high kinetic orders could be represented by a polynuclear surface nucleation growth mechanism. The activation energy for the growth of lovastatin was measured as 280 kJ/mol.

  9. Repair on the go: E. coli maintains a high proliferation rate while repairing a chronic DNA double-strand break.

    PubMed

    Darmon, Elise; Eykelenboom, John K; Lopez-Vernaza, Manuel A; White, Martin A; Leach, David R F

    2014-01-01

    DNA damage checkpoints exist to promote cell survival and the faithful inheritance of genetic information. It is thought that one function of such checkpoints is to ensure that cell division does not occur before DNA damage is repaired. However, in unicellular organisms, rapid cell multiplication confers a powerful selective advantage, leading to a dilemma. Is the activation of a DNA damage checkpoint compatible with rapid cell multiplication? By uncoupling the initiation of DNA replication from cell division, the Escherichia coli cell cycle offers a solution to this dilemma. Here, we show that a DNA double-strand break, which occurs once per replication cycle, induces the SOS response. This SOS induction is needed for cell survival due to a requirement for an elevated level of expression of the RecA protein. Cell division is delayed, leading to an increase in average cell length but with no detectable consequence on mutagenesis and little effect on growth rate and viability. The increase in cell length caused by chronic DNA double-strand break repair comprises three components: two types of increase in the unit cell size, one independent of SfiA and SlmA, the other dependent of the presence of SfiA and the absence of SlmA, and a filamentation component that is dependent on the presence of either SfiA or SlmA. These results imply that chronic checkpoint induction in E. coli is compatible with rapid cell multiplication. Therefore, under conditions of chronic low-level DNA damage, the SOS checkpoint operates seamlessly in a cell cycle where the initiation of DNA replication is uncoupled from cell division.

  10. High temperature growth of Ag phases on Ge(111)

    SciTech Connect

    Mullet, Cory H.; Chiang, Shirley

    2013-03-15

    The growth of the (3 Multiplication-Sign 1) and ({radical}3 Multiplication-Sign {radical}3)R30 Degree-Sign phases of Ag on Ge(111) on substrates at temperatures from 540 to 660 Degree-Sign C is characterized with low energy electron microscopy (LEEM) and low energy electron diffraction (LEED). From 540 Degree-Sign C to the Ag desorption temperature of 575 Degree-Sign C, LEEM images show that growth of the (3 Multiplication-Sign 1) phase begins at step edges. Upon completion of the (3 Multiplication-Sign 1) phase, the ({radical}3 Multiplication-Sign {radical}3)R30 Degree-Sign phase is observed with a dendritic growth morphology that is not much affected by steps. For sufficiently high deposition rates, Ag accumulates on the sample above the desorption temperature. From 575 to 640 Degree-Sign C, the growth proceeded in a manner similar to that at lower temperatures, with growth of the (3 Multiplication-Sign 1) phase to completion, followed by growth of the ({radical}3 Multiplication-Sign {radical}3)R30 Degree-Sign phase. Increasing the substrate temperature to 660 Degree-Sign C resulted in only (3 Multiplication-Sign 1) growth. In addition, for samples with Ag coverage less than 0.375ML, LEEM and LEED images were used to follow a reversible phase transformation near 575 Degree-Sign C, between a mixed high coverage phase of [(4 Multiplication-Sign 4) + (3 Multiplication-Sign 1)] and the high temperature, lower coverage (3 Multiplication-Sign 1) phase.

  11. Does the Slow-Growth, High-Mortality Hypothesis Apply Below Ground?

    PubMed Central

    Bennett, Alison E.; Johnson, Scott N.; Gange, Alan C.

    2016-01-01

    Belowground tri-trophic study systems present a challenging environment in which to study plant-herbivore-natural enemy interactions. For this reason, belowground examples are rarely available for testing general ecological theories. To redress this imbalance, we present, for the first time, data on a belowground tri-trophic system to test the slow growth, high mortality hypothesis. We investigated whether the differing performance of entomopathogenic nematodes (EPNs) in controlling the common pest black vine weevil Otiorhynchus sulcatus could be linked to differently resistant cultivars of the red raspberry Rubus idaeus. The O. sulcatus larvae recovered from R. idaeus plants showed significantly slower growth and higher mortality on the Glen Rosa cultivar, relative to the more commercially favored Glen Ample cultivar creating a convenient system for testing this hypothesis. Heterorhabditis megidis was found to be less effective at controlling O. sulcatus than Steinernema kraussei, but conformed to the hypothesis. However, S. kraussei maintained high levels of O. sulcatus mortality regardless of how larval growth was influenced by R. idaeus cultivar. We link this to direct effects that S. kraussei had on reducing O. sulcatus larval mass, indicating potential sub-lethal effects of S. kraussei, which the slow-growth, high-mortality hypothesis does not account for. Possible origins of these sub-lethal effects of EPN infection and how they may impact on a hypothesis designed and tested with aboveground predator and parasitoid systems are discussed. PMID:27571368

  12. Does the Slow-Growth, High-Mortality Hypothesis Apply Below Ground?

    PubMed

    Hourston, James E; Bennett, Alison E; Johnson, Scott N; Gange, Alan C

    2016-01-01

    Belowground tri-trophic study systems present a challenging environment in which to study plant-herbivore-natural enemy interactions. For this reason, belowground examples are rarely available for testing general ecological theories. To redress this imbalance, we present, for the first time, data on a belowground tri-trophic system to test the slow growth, high mortality hypothesis. We investigated whether the differing performance of entomopathogenic nematodes (EPNs) in controlling the common pest black vine weevil Otiorhynchus sulcatus could be linked to differently resistant cultivars of the red raspberry Rubus idaeus. The O. sulcatus larvae recovered from R. idaeus plants showed significantly slower growth and higher mortality on the Glen Rosa cultivar, relative to the more commercially favored Glen Ample cultivar creating a convenient system for testing this hypothesis. Heterorhabditis megidis was found to be less effective at controlling O. sulcatus than Steinernema kraussei, but conformed to the hypothesis. However, S. kraussei maintained high levels of O. sulcatus mortality regardless of how larval growth was influenced by R. idaeus cultivar. We link this to direct effects that S. kraussei had on reducing O. sulcatus larval mass, indicating potential sub-lethal effects of S. kraussei, which the slow-growth, high-mortality hypothesis does not account for. Possible origins of these sub-lethal effects of EPN infection and how they may impact on a hypothesis designed and tested with aboveground predator and parasitoid systems are discussed.

  13. Spotsizer: High-throughput quantitative analysis of microbial growth.

    PubMed

    Bischof, Leanne; Převorovský, Martin; Rallis, Charalampos; Jeffares, Daniel C; Arzhaeva, Yulia; Bähler, Jürg

    2016-10-01

    Microbial colony growth can serve as a useful readout in assays for studying complex genetic interactions or the effects of chemical compounds. Although computational tools for acquiring quantitative measurements of microbial colonies have been developed, their utility can be compromised by inflexible input image requirements, non-trivial installation procedures, or complicated operation. Here, we present the Spotsizer software tool for automated colony size measurements in images of robotically arrayed microbial colonies. Spotsizer features a convenient graphical user interface (GUI), has both single-image and batch-processing capabilities, and works with multiple input image formats and different colony grid types. We demonstrate how Spotsizer can be used for high-throughput quantitative analysis of fission yeast growth. The user-friendly Spotsizer tool provides rapid, accurate, and robust quantitative analyses of microbial growth in a high-throughput format. Spotsizer is freely available at https://data.csiro.au/dap/landingpage?pid=csiro:15330 under a proprietary CSIRO license.

  14. Growth of lead-tin telluride crystals under high gravity

    NASA Astrophysics Data System (ADS)

    Regel, L. L.; Turchaninov, A. M.; Shumaev, O. V.; Bandeira, I. N.; An, C. Y.; Rappl, P. H. O.

    1992-04-01

    The influence of high gravity environment on several growth habits of lead-tin telluride crystals began to be investigated. Preliminary experiments with Pb 0.8Sn 0.2te grown by the Bridgman technique had been made at the centrifuge facilities of the Y.A. Gagarin Cosmonauts Center in the USSR, using accelerations of 5 g, 5.2 g and 8 g. The Sn distribution for these crystals was compared with that obtained for growth at normal gravity and the results show the existence of significant compositional inhomogeneities along the axial direction. Convection currents at high gravity seem to help multiple nucleation and subsequent random orientation of growth. Analyses of carrier concentrations as well as morphological characteristics were also made.

  15. Spotsizer: High-throughput quantitative analysis of microbial growth

    PubMed Central

    Jeffares, Daniel C.; Arzhaeva, Yulia; Bähler, Jürg

    2017-01-01

    Microbial colony growth can serve as a useful readout in assays for studying complex genetic interactions or the effects of chemical compounds. Although computational tools for acquiring quantitative measurements of microbial colonies have been developed, their utility can be compromised by inflexible input image requirements, non-trivial installation procedures, or complicated operation. Here, we present the Spotsizer software tool for automated colony size measurements in images of robotically arrayed microbial colonies. Spotsizer features a convenient graphical user interface (GUI), has both single-image and batch-processing capabilities, and works with multiple input image formats and different colony grid types. We demonstrate how Spotsizer can be used for high-throughput quantitative analysis of fission yeast growth. The user-friendly Spotsizer tool provides rapid, accurate, and robust quantitative analyses of microbial growth in a high-throughput format. Spotsizer is freely available at https://data.csiro.au/dap/landingpage?pid=csiro:15330 under a proprietary CSIRO license. PMID:27712582

  16. High relative humidity increases yield, harvest index, flowering, and gynophore growth of hydroponically grown peanut plants

    NASA Technical Reports Server (NTRS)

    Mortley, D. G.; Bonsi, C. K.; Loretan, P. A.; Hill, W. A.; Morris, C. E.

    2000-01-01

    Growth chamber experiments were conducted to study the physiological and growth response of peanut (Arachis hypogaea L.) to 50% and 85% relative humidity (RH). The objective was to determine the effects of RH on pod and seed yield, harvest index, and flowering of peanut grown by the nutrient film technique (NFT). 'Georgia Red' peanut plants (14 days old) were planted into growth channels (0.15 x 0.15 x 1.2 m). Plants were spaced 25 cm apart with 15 cm between channels. A modified half-Hoagland solution with an additional 2 mM Ca was used. Solution pH was maintained between 6.4 and 6.7, and electrical conductivity (EC) ranged between 1100 and 1200 microS cm-1. Temperature regimes of 28/22 degrees C were maintained during the light/dark periods (12 hours each) with photosynthetic photon flux (PPF) at canopy level of 500 micromoles-m-2s-1. Foliage and pod fresh and dry weights, total seed yield, harvest index (HI), and seed maturity were greater at high than at low RH. Plants grown at 85% RH had greater total and individual leaflet area and stomatal conductance, flowered 3 days earlier and had a greater number of flowers reaching anthesis. Gynophores grew more rapidly at 85% than at 50% RH.

  17. High relative humidity increases yield, harvest index, flowering, and gynophore growth of hydroponically grown peanut plants

    NASA Technical Reports Server (NTRS)

    Mortley, D. G.; Bonsi, C. K.; Loretan, P. A.; Hill, W. A.; Morris, C. E.

    2000-01-01

    Growth chamber experiments were conducted to study the physiological and growth response of peanut (Arachis hypogaea L.) to 50% and 85% relative humidity (RH). The objective was to determine the effects of RH on pod and seed yield, harvest index, and flowering of peanut grown by the nutrient film technique (NFT). 'Georgia Red' peanut plants (14 days old) were planted into growth channels (0.15 x 0.15 x 1.2 m). Plants were spaced 25 cm apart with 15 cm between channels. A modified half-Hoagland solution with an additional 2 mM Ca was used. Solution pH was maintained between 6.4 and 6.7, and electrical conductivity (EC) ranged between 1100 and 1200 microS cm-1. Temperature regimes of 28/22 degrees C were maintained during the light/dark periods (12 hours each) with photosynthetic photon flux (PPF) at canopy level of 500 micromoles-m-2s-1. Foliage and pod fresh and dry weights, total seed yield, harvest index (HI), and seed maturity were greater at high than at low RH. Plants grown at 85% RH had greater total and individual leaflet area and stomatal conductance, flowered 3 days earlier and had a greater number of flowers reaching anthesis. Gynophores grew more rapidly at 85% than at 50% RH.

  18. High relative humidity increases yield, harvest index, flowering, and gynophore growth of hydroponically grown peanut plants.

    PubMed

    Mortley, D G; Bonsi, C K; Loretan, P A; Hill, W A; Morris, C E

    2000-02-01

    Growth chamber experiments were conducted to study the physiological and growth response of peanut (Arachis hypogaea L.) to 50% and 85% relative humidity (RH). The objective was to determine the effects of RH on pod and seed yield, harvest index, and flowering of peanut grown by the nutrient film technique (NFT). 'Georgia Red' peanut plants (14 days old) were planted into growth channels (0.15 x 0.15 x 1.2 m). Plants were spaced 25 cm apart with 15 cm between channels. A modified half-Hoagland solution with an additional 2 mM Ca was used. Solution pH was maintained between 6.4 and 6.7, and electrical conductivity (EC) ranged between 1100 and 1200 microS cm-1. Temperature regimes of 28/22 degrees C were maintained during the light/dark periods (12 hours each) with photosynthetic photon flux (PPF) at canopy level of 500 micromoles-m-2s-1. Foliage and pod fresh and dry weights, total seed yield, harvest index (HI), and seed maturity were greater at high than at low RH. Plants grown at 85% RH had greater total and individual leaflet area and stomatal conductance, flowered 3 days earlier and had a greater number of flowers reaching anthesis. Gynophores grew more rapidly at 85% than at 50% RH.

  19. Anomolous Fatigue Crack Growth Phenomena in High-Strength Steel

    NASA Technical Reports Server (NTRS)

    Forth, Scott C.; James, Mark A.; Johnston, William M., Jr.; Newman, James C., Jr.

    2004-01-01

    The growth of a fatigue crack through a material is the result of a complex interaction between the applied loading, component geometry, three-dimensional constraint, load history, environment, material microstructure and several other factors. Previous studies have developed experimental and computational methods to relate the fatigue crack growth rate to many of the above conditions, with the intent of discovering some fundamental material response, i.e. crack growth rate as a function of something. Currently, the technical community uses the stress intensity factor solution as a simplistic means to relate fatigue crack growth rate to loading, geometry and all other variables. The stress intensity factor solution is a very simple linear-elastic representation of the continuum mechanics portion of crack growth. In this paper, the authors present fatigue crack growth rate data for two different high strength steel alloys generated using standard methods. The steels exhibit behaviour that appears unexplainable, compared to an aluminium alloy presented as a baseline for comparison, using the stress intensity factor solution.

  20. Functional approach to high-throughput plant growth analysis

    PubMed Central

    2013-01-01

    Method Taking advantage of the current rapid development in imaging systems and computer vision algorithms, we present HPGA, a high-throughput phenotyping platform for plant growth modeling and functional analysis, which produces better understanding of energy distribution in regards of the balance between growth and defense. HPGA has two components, PAE (Plant Area Estimation) and GMA (Growth Modeling and Analysis). In PAE, by taking the complex leaf overlap problem into consideration, the area of every plant is measured from top-view images in four steps. Given the abundant measurements obtained with PAE, in the second module GMA, a nonlinear growth model is applied to generate growth curves, followed by functional data analysis. Results Experimental results on model plant Arabidopsis thaliana show that, compared to an existing approach, HPGA reduces the error rate of measuring plant area by half. The application of HPGA on the cfq mutant plants under fluctuating light reveals the correlation between low photosynthetic rates and small plant area (compared to wild type), which raises a hypothesis that knocking out cfq changes the sensitivity of the energy distribution under fluctuating light conditions to repress leaf growth. Availability HPGA is available at http://www.msu.edu/~jinchen/HPGA. PMID:24565437

  1. Growth depth effects of bacteria in ground turkey meat patties subjected to high carbon dioxide or high oxygen atmospheres.

    PubMed

    Dhananjayan, R; Han, I Y; Acton, J C; Dawson, P L

    2006-10-01

    Modified atmosphere packaging (MAP) is used to extend the shelf life of ground meats by altering the gas atmosphere surrounding the meat. This study evaluated how deep MAP bactericidal effects penetrate into a ground meat patty. Patties made from freshly ground turkey breasts were subjected to 2 MAP treatments of high CO(2) (97%) or high O(2) (80% O(2), 20% CO(2)). Total plate and lactic acid bacterial counts were determined for 3 patty depths (top, middle, bottom). Meat surface color and the package gas headspace composition were also measured. All analyses were performed on 0, 3, 6, 9, and 12 d. Changes in gas headspace and meat surface color were also measured at 0, 3, 6, 9, and 12 d. High CO(2) atmosphere maintained a better meat surface color than high O(2) atmosphere over the whole storage period. Overall counts were lower (P < or = 0.05) in a high-CO(2) atmosphere compared with a high-O(2) modified atmosphere. Patties stored under a high-CO(2) atmosphere displayed slower bacterial growth in the top layer compared with the middle and bottom layers. Total plate count did not differ (P > or = 0.05) in layers for patties pack-aged in a high-O(2) atmosphere Lactic acid bacterial counts increased in the high-O(2) modified atmosphere by d 9 and 12 of storage; no increase was observed in CO(2)-packaged patties. Thus, high-CO(2) MAP slowed the growth of total bacteria as well as lactic acid bacteria. Also, there was slower growth in the top meat layer exposed to CO(2) compared with interior layers.

  2. State investments in high-technology job growth.

    PubMed

    Leicht, Kevin T; Jenkins, J Craig

    2017-07-01

    Since the early 1970's state and local governments have launched an array of economic development programs designed to promote high-technology development. The question our analysis addresses is whether these programs promote long-term high-technology employment growth net of state location and agglomeration advantages. Proponents talk about an infrastructure strategy that promotes investment in public research and specialized infrastructure to attract and grow new high technology industries in specific locations, and a more decentralized entrepreneurial strategy that reinforces local agglomeration capacities by investing in new enterprises and products, promoting the development of local networks and partnerships. Our results support the entrepreneurial strategy, suggesting that state governments can accelerate high technology development by adopting market-supportive programs that complement private sector initiatives. In addition to positive direct benefits of technology deployment/transfer programs and SBIR programs, entrepreneurial programs affect change in high-technology employment in concert with existing locational and agglomeration advantages. Rural (i.e. low population density) states tend to benefit by technology development programs. Infrastructure strategy programs also facilitate high technology job growth in places where local advantages already exist. Our results suggest that critics of industrial policy are correct that high technology growth is organic and endogenous, yet state governments are able to "pick winners and losers" in ways that grow their local economy. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Interferon beta overexpression attenuates adipose tissue inflammation and high-fat diet-induced obesity and maintains glucose homeostasis.

    PubMed

    Alsaggar, M; Mills, M; Liu, D

    2017-01-01

    The worldwide prevalence of obesity is increasing, raising health concerns regarding obesity-related complications. Chronic inflammation has been characterized as a major contributor to the development of obesity and obesity-associated metabolic disorders. The purpose of the current study is to assess whether the overexpression of interferon beta (IFNβ1), an immune-modulating cytokine, will attenuate high-fat diet-induced adipose inflammation and protect animals against obesity development. Using hydrodynamic gene transfer to elevate and sustain blood concentration of IFNβ1 in mice fed a high-fat diet, we showed that the overexpression of Ifnβ1 gene markedly suppressed immune cell infiltration into adipose tissue, and attenuated production of pro-inflammatory cytokines. Systemically, IFNβ1 blocked adipose tissue expansion and body weight gain, independent of food intake. Possible browning of white adipose tissue might also contribute to blockade of weight gain. More importantly, IFNβ1 improved insulin sensitivity and glucose homeostasis. These results suggest that targeting inflammation represents a practical strategy to block the development of obesity and its related pathologies. In addition, IFNβ1-based therapies have promising potential for clinical applications for the prevention and treatment of various inflammation-driven pathologies.

  4. Increased Peptide Contacts Govern High Affinity Binding of a Modified TCR Whilst Maintaining a Native pMHC Docking Mode.

    PubMed

    Cole, David K; Sami, Malkit; Scott, Daniel R; Rizkallah, Pierre J; Borbulevych, Oleg Y; Todorov, Penio T; Moysey, Ruth K; Jakobsen, Bent K; Boulter, Jonathan M; Baker, Brian M; Yi Li

    2013-01-01

    Natural T cell receptors (TCRs) generally bind to their cognate pMHC molecules with weak affinity and fast kinetics, limiting their use as therapeutic agents. Using phage display, we have engineered a high affinity version of the A6 wild-type TCR (A6wt), specific for the human leukocyte antigen (HLA-A(∗)0201) complexed with human T cell lymphotropic virus type 111-19 peptide (A2-Tax). Mutations in just 4 residues in the CDR3β loop region of the A6wt TCR were selected that improved binding to A2-Tax by nearly 1000-fold. Biophysical measurements of this mutant TCR (A6c134) demonstrated that the enhanced binding was derived through favorable enthalpy and a slower off-rate. The structure of the free A6c134 TCR and the A6c134/A2-Tax complex revealed a native binding mode, similar to the A6wt/A2-Tax complex. However, concordant with the more favorable binding enthalpy, the A6c134 TCR made increased contacts with the Tax peptide compared with the A6wt/A2-Tax complex, demonstrating a peptide-focused mechanism for the enhanced affinity that directly involved the mutated residues in the A6c134 TCR CDR3β loop. This peptide-focused enhanced TCR binding may represent an important approach for developing antigen specific high affinity TCR reagents for use in T cell based therapies.

  5. Incidence of high dosage buprenorphine and methadone shopping behavior in a retrospective cohort of opioid-maintained patients in France.

    PubMed

    Delorme, Jessica; Chenaf, Chouki; Kabore, Jean-Luc; Pereira, Bruno; Mulliez, Aurélien; Tremey, Aurore; Brousse, Georges; Zenut, Marie; Laporte, Catherine; Authier, Nicolas

    2016-05-01

    Opioid Substitution Treatment (OST) misuse and diversion have significantly increased worldwide. Obtaining OST prescriptions from multiple prescribers, known as doctor shopping, is a way in which opioids may be diverted. The aim of this study was to assess the incidence of OST (high dosage buprenorphine (HDB) and methadone (MTD)) shopping behavior and identify associated risk factors, and its impact on mortality. A retrospective cohort of patients treated by OST between April 1, 2004 and December 31, 2012 from a sample of the French Health Insurance database was established. Doctor shopping was defined as ≥1 day of overlapping prescriptions written by ≥2 different prescribers and filled in ≥3 different pharmacies. A total of 2043 patients were enrolled, 1450HDB and 593 MTD. The one-year incidence of shopping behavior was 8.4% (95% CI: 7.0-10.1) in HDB group and 0% in MTD group, compared to 0.2% (95% CI: 0.1-0.2) for diuretics. On multivariate analysis, factors associated with HDB shopping behavior were: male gender HR: 1.74 (95% CI: 1.20-2.54); low-income status HR: 2.95 (95% CI: 2.07-4.44); mental health disorders HR: 1.43 (95% CI: 1.06-1.94); concurrent hypnotics use HR: 1.90 (95% CI: 1.39-2.61); concurrent use of weak opioids HR: 1.48 (95% CI: 1.09-1.99) and morphine HR: 1.69 (95% CI: 1.02-2.80). HDB shoppers had a higher, yet non-significant risk of death (HR: 1.56 (95% CI: 0.64-3.81)) than non HDB shoppers. Shopping behavior was only found in high dosage buprenorphine patients and concerned almost one out ten patients. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  6. High light decreases xylem contribution to fruit growth in tomato.

    PubMed

    Hanssens, Jochen; DE Swaef, Tom; Steppe, Kathy

    2015-03-01

    Recently, contradicting evidence has been reported on the contribution of xylem and phloem influx into tomato fruits, urging the need for a better understanding of the mechanisms involved in fruit growth. So far, little research has been performed on quantifying the effect of light intensity on the different contributors to the fruit water balance. However, as light intensity affects both transpiration and photosynthesis, it might be expected to induce important changes in the fruit water balance. In this study, tomato plants (Solanum lycopersicum L.) were grown in light and shade conditions and the fruit water balance was studied by measuring fruit growth of girdled and intact fruits with linear variable displacement transducers combined with a model-based approach. Results indicated that the relative xylem contribution significantly increased when shading lowered light intensity. This resulted from both a higher xylem influx and a lower phloem influx during the daytime. Plants from the shade treatment were able to maintain a stronger gradient in total water potential between stem and fruits during daytime, thereby promoting xylem influx. It appeared that the xylem pathway was still functional at 35 days after anthesis and that relative xylem contribution was strongly affected by environmental conditions.

  7. Obtaining and maintaining funding

    SciTech Connect

    Beverly Hartline

    1996-04-01

    Obtaining and maintaining funding is important for individuals, groups, institutions, and fields. This challenge is easier during times of abundant and growing resources than it is now, when funding is tight and shrinking. Thus, to obtain and maintain funding will require: maintaining healthy funding levels for all of science; maintaining healthy funding levels for the field(s) you work in; and competing successfully for the available funds. Everyone should pay attention to the overall prospects for science funding and dedicate some effort to working with others to grow the constituency for science. Public support is likely an important prerequisite for keeping future science budgets high. In this context, researchers should share with society at large the benefits of their research, so that taxpayers can see and appreciate some return from the federal investment in science. Assuming this effort is successful, and there continue to be government and private organizations with substantial resources to invest in research, what can the individual investigator do to improve her chances? She can be clear about her goal(s) and carefully plan her effort to make maximum progress for minimum resources, especially early in her career while she is establishing a solid professional reputation. Specific useful strategies include: brainstorm funding options and select the most promising one(s); be persistent but flexible, responsive to new information and changing circumstances; provide value and assistance to prospective funding sources both before and after receiving funding; know the funding agents and what their goals are, they are the customers; promise a lot and always deliver more; build partnerships and collaboration to leverage interest and resources; and develop capabilities and ideas with a promising, irresistible future. There is no guarantee of success. For the best chances, consistently contribute positively and productively in all your efforts, and continue to

  8. The ability of exogenous growth hormone to maintain milk production during prolonged lactation in the mouse is more evident with reduced nursing frequency

    USDA-ARS?s Scientific Manuscript database

    Although growth hormone (GH) increases milk production in dairy animals, the milk production response of lactating rodents to this treatment has been variable. Milk removal frequency in the lactating mouse is about 10-fold higher than that of lactating dairy cows. The hypothesis tested in this study...

  9. The Microtubule Plus-End Tracking Proteins SPR1 and EB1b Interact to Maintain Polar Cell Elongation and Directional Organ Growth in Arabidopsis[W

    PubMed Central

    Galva, Charitha; Kirik, Viktor; Lindeboom, Jelmer J.; Kaloriti, Despoina; Rancour, David M.; Hussey, Patrick J.; Bednarek, Sebastian Y.; Ehrhardt, David W.; Sedbrook, John C.

    2014-01-01

    The microtubule plus-end tracking proteins (+TIPs) END BINDING1b (EB1b) and SPIRAL1 (SPR1) are required for normal cell expansion and organ growth. EB proteins are viewed as central regulators of +TIPs and cell polarity in animals; SPR1 homologs are specific to plants. To explore if EB1b and SPR1 fundamentally function together, we combined genetic, biochemical, and cell imaging approaches in Arabidopsis thaliana. We found that eb1b-2 spr1-6 double mutant roots exhibit substantially more severe polar expansion defects than either single mutant, undergoing right-looping growth and severe axial twisting instead of waving on tilted hard-agar surfaces. Protein interaction assays revealed that EB1b and SPR1 bind each other and tubulin heterodimers, which is suggestive of a microtubule loading mechanism. EB1b and SPR1 show antagonistic association with microtubules in vitro. Surprisingly, our combined analyses revealed that SPR1 can load onto microtubules and function independently of EB1 proteins, setting SPR1 apart from most studied +TIPs in animals and fungi. Moreover, we found that the severity of defects in microtubule dynamics in spr1 eb1b mutant hypocotyl cells correlated well with the severity of growth defects. These data indicate that SPR1 and EB1b have complex interactions as they load onto microtubule plus ends and direct polar cell expansion and organ growth in response to directional cues. PMID:25415978

  10. The microtubule plus-end tracking proteins SPR1 and EB1b interact to maintain polar cell elongation and directional organ growth in Arabidopsis.

    PubMed

    Galva, Charitha; Kirik, Viktor; Lindeboom, Jelmer J; Kaloriti, Despoina; Rancour, David M; Hussey, Patrick J; Bednarek, Sebastian Y; Ehrhardt, David W; Sedbrook, John C

    2014-11-01

    The microtubule plus-end tracking proteins (+TIPs) END BINDING1b (EB1b) and SPIRAL1 (SPR1) are required for normal cell expansion and organ growth. EB proteins are viewed as central regulators of +TIPs and cell polarity in animals; SPR1 homologs are specific to plants. To explore if EB1b and SPR1 fundamentally function together, we combined genetic, biochemical, and cell imaging approaches in Arabidopsis thaliana. We found that eb1b-2 spr1-6 double mutant roots exhibit substantially more severe polar expansion defects than either single mutant, undergoing right-looping growth and severe axial twisting instead of waving on tilted hard-agar surfaces. Protein interaction assays revealed that EB1b and SPR1 bind each other and tubulin heterodimers, which is suggestive of a microtubule loading mechanism. EB1b and SPR1 show antagonistic association with microtubules in vitro. Surprisingly, our combined analyses revealed that SPR1 can load onto microtubules and function independently of EB1 proteins, setting SPR1 apart from most studied +TIPs in animals and fungi. Moreover, we found that the severity of defects in microtubule dynamics in spr1 eb1b mutant hypocotyl cells correlated well with the severity of growth defects. These data indicate that SPR1 and EB1b have complex interactions as they load onto microtubule plus ends and direct polar cell expansion and organ growth in response to directional cues.

  11. High Frequency Nasal Ventilation for 21 Days Maintains Gas Exchange with Lower Respiratory Pressures and Promotes Alveolarization in Preterm Lambs

    PubMed Central

    Null, Donald M.; Alvord, Jeremy; Leavitt, Wendy; Wint, Albert; Dahl, Mar Janna; Presson, Angela P.; Lane, Robert H.; DiGeronimo, Robert J.; Yoder, Bradley A.; Albertine, Kurt H.

    2014-01-01

    Background Short-term high-frequency nasal ventilation (HFNV) of preterm neonates provides acceptable gas exchange compared to endotracheal intubation and intermittent mandatory ventilation (IMV). Whether long-term HFNV will provide acceptable gas exchange is unknown. We hypothesized that HFNV for up to 21d would lead to acceptable gas exchange at lower inspired oxygen (O2) levels and airway pressures compared to intubation and IMV. Methods Preterm lambs were exposed to antenatal steroids, and treated with perinatal surfactant and postnatal caffeine. Lambs were intubated and resuscitated by IMV. At ~3h of age, half of the lambs were switched to non-invasive HFNV. Support was for 3d or 21d. By design, PaO2 and PaCO2 were not different between groups. Results At 3d (n=5) and 21d (n=4) of HFNV, fractional inspired O2 (FiO2), peak inspiratory pressure, mean airway, intra-tracheal, and positive end-expiratory pressures, oxygenation index, and Alveolar-arterial gradient were significantly lower than matched periods of intubation and IMV. PaO2/FiO2 ratio was significantly higher at 3d and 21d of HFNV compared to matched intubation and IMV. HFNV led to better alveolarization at 3d and 21d. Conclusion Long-term HFNV provides acceptable gas exchange at lower inspired O2 levels and respiratory pressures compared to intubation and IMV. PMID:24378898

  12. Nanosuspensions of 10-hydroxycamptothecin that can maintain high and extended supersaturation to enhance oral absorption: preparation, characterization and in vitro/in vivo evaluation

    NASA Astrophysics Data System (ADS)

    Pu, Xiaohui; Sun, Jin; Han, Jihong; Lian, He; Zhang, Peng; Yan, Zhongtian; He, Zhonggui

    2013-11-01

    The purpose of the study was to prepare and characterize nanosuspensions that can maintain high and extended supersaturation to improve the dissolution and absorption of poorly soluble 10-hydroxycamptothecin (10-HCPT). 10-HCPT oral nanosuspensions (HCPT-Nanosuspensions) were produced on a laboratory-scale by microprecipitation- high pressure homogenization method. The particle morphology and the physical state were studied using transmission electron microscopy, X-ray powder diffraction (XRPD), and differential scanning calorimetry (DSC). Supersaturated dissolution tests were carried out with the paddle method. Caco-2 cell experiments were performed to imitate the oral absorption. The in vivo pharmacokinetics studies were undertaken in rats following oral administration. The 10-HCPT nanoparticles were 135 nm in dimension before lyophilization and were claviform or lump in shape. XRPD and DSC both confirmed that a portion of 10-HCPT was present in a crystalline state in nanosuspension. Supersaturated dissolution tests showed HCPT-Nanosuspensions could maintain high supersaturated level for an extended period time. The cell experiment on HCPT-Nanosuspensions showed a significantly higher uptake and greater membrane permeability compared with the other formulations. The pharmacokinetic test exhibited HCPT-Nanosuspensions had a similar pharmacokinetic performance with 10-HCPT solution. In conclusion, highly and extendedly supersaturated HCPT-Nanosuspensions have been prepared which could result in high peak concentration ( C max) and great exposure (AUC) after oral administration.

  13. High-quality and high-purity homoepitaxial diamond (100) film growth under high oxygen concentration condition

    SciTech Connect

    Teraji, Tokuyuki

    2015-09-21

    Defect formation during diamond homoepitaxial growth was sufficiently inhibited by adding oxygen simultaneously in the growth ambient with high concentration of 2%. A 30-μm thick diamond films with surface roughness of <2 nm were homoepitaxially deposited on the (100) diamond single crystal substrates with reasonable growth rate of approximately 3 μm h{sup −1} under the conditions of higher methane concentration of 10%, higher substrate temperature of ∼1000 °C, and higher microwave power density condition of >100 W cm{sup −3}. Surface characteristic patterns moved to an identical direction with growth thickness, indicating that lateral growth was dominant growth mode. High chemical purity represented by low nitrogen concentration of less than 1 ppb and the highest {sup 12}C isotopic ratio of 99.998% of the obtained homoepitaxial diamond (100) films suggest that the proposed growth condition has high ability of impurity control.

  14. Jasmonate Controls Leaf Growth by Repressing Cell Proliferation and the Onset of Endoreduplication while Maintaining a Potential Stand-By Mode1[W][OA

    PubMed Central

    Noir, Sandra; Bömer, Moritz; Takahashi, Naoki; Ishida, Takashi; Tsui, Tjir-Li; Balbi, Virginia; Shanahan, Hugh; Sugimoto, Keiko; Devoto, Alessandra

    2013-01-01

    Phytohormones regulate plant growth from cell division to organ development. Jasmonates (JAs) are signaling molecules that have been implicated in stress-induced responses. However, they have also been shown to inhibit plant growth, but the mechanisms are not well understood. The effects of methyl jasmonate (MeJA) on leaf growth regulation were investigated in Arabidopsis (Arabidopsis thaliana) mutants altered in JA synthesis and perception, allene oxide synthase and coi1-16B (for coronatine insensitive1), respectively. We show that MeJA inhibits leaf growth through the JA receptor COI1 by reducing both cell number and size. Further investigations using flow cytometry analyses allowed us to evaluate ploidy levels and to monitor cell cycle progression in leaves and cotyledons of Arabidopsis and/or Nicotiana benthamiana at different stages of development. Additionally, a novel global transcription profiling analysis involving continuous treatment with MeJA was carried out to identify the molecular players whose expression is regulated during leaf development by this hormone and COI1. The results of these studies revealed that MeJA delays the switch from the mitotic cell cycle to the endoreduplication cycle, which accompanies cell expansion, in a COI1-dependent manner and inhibits the mitotic cycle itself, arresting cells in G1 phase prior to the S-phase transition. Significantly, we show that MeJA activates critical regulators of endoreduplication and affects the expression of key determinants of DNA replication. Our discoveries also suggest that MeJA may contribute to the maintenance of a cellular “stand-by mode” by keeping the expression of ribosomal genes at an elevated level. Finally, we propose a novel model for MeJA-regulated COI1-dependent leaf growth inhibition. PMID:23439917

  15. Jasmonate controls leaf growth by repressing cell proliferation and the onset of endoreduplication while maintaining a potential stand-by mode.

    PubMed

    Noir, Sandra; Bömer, Moritz; Takahashi, Naoki; Ishida, Takashi; Tsui, Tjir-Li; Balbi, Virginia; Shanahan, Hugh; Sugimoto, Keiko; Devoto, Alessandra

    2013-04-01

    Phytohormones regulate plant growth from cell division to organ development. Jasmonates (JAs) are signaling molecules that have been implicated in stress-induced responses. However, they have also been shown to inhibit plant growth, but the mechanisms are not well understood. The effects of methyl jasmonate (MeJA) on leaf growth regulation were investigated in Arabidopsis (Arabidopsis thaliana) mutants altered in JA synthesis and perception, allene oxide synthase and coi1-16B (for coronatine insensitive1), respectively. We show that MeJA inhibits leaf growth through the JA receptor COI1 by reducing both cell number and size. Further investigations using flow cytometry analyses allowed us to evaluate ploidy levels and to monitor cell cycle progression in leaves and cotyledons of Arabidopsis and/or Nicotiana benthamiana at different stages of development. Additionally, a novel global transcription profiling analysis involving continuous treatment with MeJA was carried out to identify the molecular players whose expression is regulated during leaf development by this hormone and COI1. The results of these studies revealed that MeJA delays the switch from the mitotic cell cycle to the endoreduplication cycle, which accompanies cell expansion, in a COI1-dependent manner and inhibits the mitotic cycle itself, arresting cells in G1 phase prior to the S-phase transition. Significantly, we show that MeJA activates critical regulators of endoreduplication and affects the expression of key determinants of DNA replication. Our discoveries also suggest that MeJA may contribute to the maintenance of a cellular "stand-by mode" by keeping the expression of ribosomal genes at an elevated level. Finally, we propose a novel model for MeJA-regulated COI1-dependent leaf growth inhibition.

  16. High oleic ready-to-use therapeutic food maintains docosahexaenoic acid status in severe malnutrition: a randomized, blinded trial

    PubMed Central

    Hsieh, Ji-Cheng; Liu, Lei; Zeilani, Mamane; Ickes, Scott; Trehan, Indi; Maleta, Ken; Craig, Christina; Thakwalakwa, Chrissie; Singh, Lauren; Brenna, J. Thomas; Manary, Mark J.

    2015-01-01

    Objective Ready-to-use therapeutic food (RUTF) is the preferred treatment for uncomplicated severe acute malnutrition. RUTF contains large amounts of linoleic acid and very little α-linolenic acid, which may reduce the availability of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) to the recovering child. A novel high oleic RUTF (HO-RUTF) was developed with less linoleic acid to determine its effect on DHA and EPA status. Methods We conducted a prospective, randomized, double-blinded, clinical effectiveness trial treating rural Malawian children with severe acute malnutrition. Children were treated with either HO-RUTF or standard RUTF. Plasma phospholipid (PL) fatty acid status was measured upon enrollment and after 4 weeks and compared between the two intervention groups. Results Among the 141 children enrolled, 48/71 receiving HO-RUTF and 50/70 receiving RUTF recovered. Plasma PL samples were analyzed from 43 children consuming HO-RUTF and 35 children consuming RUTF. The change in DHA content during the first 4 weeks was +4% and −25% in the HO-RUTF and RUTF groups, respectively (P = 0.04). For EPA, the change in content was 63% and −24% in the HO-RUTF and RUTF groups (P < 0.001). For arachidonic acid, the change in content was −3% and 13% in the HO-RUTF and RUTF groups (P < 0.009). Conclusions The changes in DHA and EPA seen in the children treated with HO-RUTF warrant further investigation as they suggest HO-RUTF support improved PUFA status, necessary for neural development and recovery. PMID:25633498

  17. Age and body weight effects on glucose and insulin tolerance in colony cats maintained since weaning on high dietary carbohydrate.

    PubMed

    Backus, R C; Cave, N J; Ganjam, V K; Turner, J B M; Biourge, V C

    2010-12-01

    High dietary carbohydrate is suggested to promote development of diabetes mellitus in cats. Glucose tolerance, insulin sensitivity, and insulin secretion were assessed in young [0.8-2.3 (median = 1.1) years, n = 13] and mature [4.0-7.0 (median 5.8) years, n = 12] sexually intact females of a large (n ≅ 700) feline colony in which only dry-type diets (35% metabolizable energy as carbohydrate) were fed from weaning. Insulin sensitivity was assessed from the 'late-phase' (60-120 min) plasma insulin response of intravenous glucose tolerance tests (IVGTTs) and from fractional change in glycaemia from baseline 15 min after an insulin bolus (0.1 U/kg, i.v.). Insulin secretion was assessed from the 'early-phase' (0-15 min) plasma insulin response of IVGTTs. Compared to the young cats, the mature cats had greater body weights [2.3-3.8 (median = 2.9) vs. 3.0-6.3 (median = 4.0) kg, p < 0.01], greater late-phase insulin responses (p < 0.05), lower insulin-induced glycaemic changes (p = 0.06), lower early-phase insulin responses (p < 0.05), and non-significantly different rates of glucose disposal. The late-phase insulin response was correlated with body weight and age (p < 0.05). When group assignments were balanced for body weight, the age-group differences and correlations became non-significant. The findings indicate that body weight gain is more likely than dry-type diets to induce the pre-diabetic conditions of insulin resistance and secretion dysfunction.

  18. Dynamic changes in high and low mammographic density human breast tissues maintained in murine tissue engineering chambers during various murine peripartum states and over time.

    PubMed

    Chew, G L; Huang, D; Huo, C W; Blick, T; Hill, P; Cawson, J; Frazer, H; Southey, M D; Hopper, J L; Henderson, M A; Haviv, I; Thompson, E W

    2013-07-01

    Mammographic density (MD) is a strong heritable risk factor for breast cancer, and may decrease with increasing parity. However, the biomolecular basis for MD-associated breast cancer remains unclear, and systemic hormonal effects on MD-associated risk is poorly understood. This study assessed the effect of murine peripartum states on high and low MD tissue maintained in a xenograft model of human MD. Method High and low MD human breast tissues were precisely sampled under radiographic guidance from prophylactic mastectomy specimens of women. The high and low MD tissues were maintained in separate vascularised biochambers in nulliparous or pregnant SCID mice for 4 weeks, or mice undergoing postpartum involution or lactation for three additional weeks. High and low MD biochamber material was harvested for histologic and radiographic comparisons during various murine peripartum states. High and low MD biochamber tissues in nulliparous mice were harvested at different timepoints for histologic and radiographic comparisons. Results High MD biochamber tissues had decreased stromal (p = 0.0027), increased adipose (p = 0.0003) and a trend to increased glandular tissue areas (p = 0.076) after murine postpartum involution. Stromal areas decreased (p = 0.042), while glandular (p = 0.001) and adipose areas (p = 0.009) increased in high MD biochamber tissues during lactation. A difference in radiographic density was observed in high (p = 0.0021) or low MD biochamber tissues (p = 0.004) between nulliparous, pregnant and involution groups. No differences in tissue composition were observed in high or low MD biochamber tissues maintained for different durations, although radiographic density increased over time. Conclusion High MD biochamber tissues had measurable histologic changes after postpartum involution or lactation. Alterations in radiographic density occurred in biochamber tissues between different peripartum states and over time. These findings

  19. Reproductive failure in Arabidopsis thaliana under transient carbohydrate limitation: flowers and very young siliques are jettisoned and the meristem is maintained to allow successful resumption of reproductive growth.

    PubMed

    Lauxmann, Martin A; Annunziata, Maria G; Brunoud, Géraldine; Wahl, Vanessa; Koczut, Andrzej; Burgos, Asdrubal; Olas, Justyna J; Maximova, Eugenia; Abel, Christin; Schlereth, Armin; Soja, Aleksandra M; Bläsing, Oliver E; Lunn, John E; Vernoux, Teva; Stitt, Mark

    2016-04-01

    The impact of transient carbon depletion on reproductive growth in Arabidopsis was investigated by transferring long-photoperiod-grown plants to continuous darkness and returning them to a light-dark cycle. After 2 days of darkness, carbon reserves were depleted in reproductive sinks, and RNA in situ hybridization of marker transcripts showed that carbon starvation responses had been initiated in the meristem, anthers and ovules. Dark treatments of 2 or more days resulted in a bare-segment phenotype on the floral stem, with 23-27 aborted siliques. These resulted from impaired growth of immature siliques and abortion of mature and immature flowers. Depolarization of PIN1 protein and increased DII-VENUS expression pointed to rapid collapse of auxin gradients in the meristem and inhibition of primordia initiation. After transfer back to a light-dark cycle, flowers appeared and formed viable siliques and seeds. A similar phenotype was seen after transfer to sub-compensation point irradiance or CO2 . It also appeared in a milder form after a moderate decrease in irradiance and developed spontaneously in short photoperiods. We conclude that Arabidopsis inhibits primordia initiation and aborts flowers and very young siliques in C-limited conditions. This curtails demand, safeguarding meristem function and allowing renewal of reproductive growth when carbon becomes available again. © 2015 John Wiley & Sons Ltd.

  20. Randomised comparison of diets for maintaining obese subjects' weight after major weight loss: ad lib, low fat, high carbohydrate diet v fixed energy intake.

    PubMed

    Toubro, S; Astrup, A

    1997-01-04

    To compare importance of rate of initial weight loss for long term outcome in obese patients and to compare efficacy of two different weight maintenance programmes. Subjects were randomised to either rapid or slow initial weight loss. Completing patients were re-randomised to one year weight maintenance programme of ad lib diet or fixed energy intake diet. Patients were followed up one year later. University research department in Copenhagen, Denmark. 43 (41 women) obese adults (body mass index 27-40) who were otherwise healthy living in or around Copenhagen. 8 weeks of low energy diet (2 MJ/day) or 17 weeks of conventional diet (5 MJ/day), both supported by an anorectic compound (ephedrine 20 mg and caffeine 200 mg thrice daily); one year weight maintenance programme of ad lib, low fat, high carbohydrate diet or fixed energy intake diet (< or = 7.8 MJ/day), both with reinforcement sessions 2-3 times monthly. Mean initial weight loss and proportion of patients maintaining a weight loss of > 5 kg at follow up. Mean initial weight loss was 12.6 kg (95% confidence interval 10.9 to 14.3 kg) in rapid weight loss group and 12.6 (9.9 to 15.3) kg in conventional diet group. Rate of initial weight loss had no effect on weight maintenance after 6 or 12 months of weight maintenance or at follow up. After weight maintenance programme, the ad lib group had maintained 13.2 (8.1 to 18.3) kg of the initial weight loss of 13.5 (11.4 to 15.5) kg, and the fixed energy intake group had maintained 9.7 (6.1 to 13.3) kg of the initial 13.8 (11.8 to 15.7) kg weight loss (group difference 3.5 (-2.4 to 9.3) kg). Regained weight at follow up was greater in fixed energy intake group than in ad lib group (11.3 (7.1 to 15.5) kg v 5.4 (2.3 to 8.6) kg, group difference 5.9 (0.7 to 11.1) kg, P < 0.03). At follow up, 65% of ad lib group and 40% of fixed energy intake group had maintained a weight loss of > 5 kg (P < 0.07). Ad lib, low fat, high carbohydrate diet was superior to fixed energy intake

  1. A requirement for cell elongation protein RodZ and cell division proteins FtsN and DedD to maintain the small rod morphology of Escherichia coli at growth temperatures near 8°C.

    PubMed

    Porter, T; Frederick, D; Johnson, E; Jones, P G

    2016-09-12

    As similarly observed in nutrient-poor media at 37°C, Escherichia coli forms small rods in nutrient-rich media at temperatures near 8°C, the minimum temperature of growth. A study was initiated to identify proteins required to facilitate the small rod morphology at low temperature. E. coli contains three nonessential SPOR domain proteins (DamX, RlpA, and DedD) that have been demonstrated to bind to the septal ring. In contrast to the normal growth and small rod morphology of damX and rlpA null mutants at 10°C, the dedD null mutant exhibited reduced growth and formed filamentous cells. The presence of plasmid-encoded DedD restored growth and small rods. Plasmid-encoded FtsN, an essential SPOR domain protein that functions to stabilize the septal ring and to initiate septation, in the dedD null mutant resulted in increased growth and the formation of shorter chained cells. However, plasmid-encoded DedD failed to restore growth and cell division of cells lacking FtsN at 10°C. In contrast to cell division protein DedD, RodZ is a cell elongation protein particularly required for growth at 30°C. However, the rodZ null mutant grew similarly as the wild type strain and produced cocci in LB broth at 10°C. Moreover at 10°C, the concerted deletion of dedD and rodZ resulted in severe inhibition of growth accompanied with the formation of swollen prolate ellipsoids due to a block in septal ring assembly and cell elongation. The data indicate the cellular requirement of both FtsN and DedD for septation as well as RodZ for cell elongation to maintain the small rod morphology at temperatures near 8°C. In comparison to the growth and small rods of the wild type in M9-glucose minimal media at 37°C, the dedD null mutant grew at the same rate and produced elongated cells while the rodZ null mutant grew at a slightly slower rate and produced cocci. The data indicate that DedD and RodZ are also required to maintain the small rod morphology in nutrient-poor media, but there is a

  2. Screening of a high growth influenza B virus strain in Vero cells.

    PubMed

    Liu, Ze; Li, Wei-dong; Sun, Ming-bo; Ma, Lei; Guo, Zi-quan; Jiang, Shu-de; Liao, Guo-yang; Yang, Jing-si; Li, Chang-gui

    2010-02-01

    Due to the insufficient supply of embryonated chicken eggs, the preparation of large quantities of inactivated influenza vaccines will require an alternative virus culture system after the emergence or reemergence of a pandemic influenza virus. The Vero cell is one of the ideal options since it was used for producing many kinds of human vaccines. However, most of the influenza viruses can not grow well in Vero cells. To develop a new influenza vaccine with Vero cells as a substrate, the virus needs to adapt to this cell substrate to maintain high growth characteristics. By serial passages in Vero cells, the B/Yunnan/2/2005va (B) strain was successfully adapted to Vero cells, with the hemagglutination titer (HAT) of the virus reaching 1:512. The high growth characteristic of this strain is stable up to 21 passages. The strain was identified by hemagglutination inhibition (HAI) test and sequencing respectively; the HA₁ gene sequence of the virus was cloned and analyzed. The screening and establishment of high growth B virus provides an important tool for influenza vaccine production in Vero cells.

  3. Crystal growth of energetic materials during high acceleration

    SciTech Connect

    Lanzerotti, M.Y.D.; Autera, J.; Borne, L.; Sharma, J.

    1996-07-01

    Studies of the growth of crystals of energetic materials under conditions of high acceleration in an ultracentrifuge are reported. When a saturated solution is accelerated in an ultracentrifuge, the solute molecules move individually through the solvent molecules to form a crystal at the outer edge of the tube if the solute is more dense than the solvent. Since there is no evaporation or temperature variation, convection currents caused by simultaneous movement of solvent and solute are minimized and crystal defects are potentially minimized. Crystal growth is controlled by the g-level of the acceleration. In addition, solution inclusions and bubbles migrate out of the saturated solution as a result of the pressure gradient induced by the g-force. The authors present results of TNT, RDX, and TNAZ grown at high g from various solutions.

  4. Growth of Nanowires by High-Temperature Glancing Angle Deposition

    NASA Astrophysics Data System (ADS)

    Suzuki, Motofumi; Minamitake, Haruhiko; Kita, Ryo; Hamachi, Kenji; Hara, Hideki; Nakajima, Kaoru; Kimura, Kenji; Hsu, Chia-Wei; Chou, Li-Jen

    2013-11-01

    We have demonstrated that nanowires of various metals, Ge, and Ga2O3 can be grown by high-temperature glancing angle deposition (HT-GLAD). The nanowires of metals including Al, Cu, Ag, Au, Mn, Fe, Co, Ni, and Zn are self-catalyzed, while the nanowires of other materials such as Ge and Ga2O3 are catalyzed by Au nanoparticles. However, once the nanowires start to grow, the growth modes of the HT-GLAD nanowires are fundamentally the same, i.e., nanowires with uniform diameter grow only when the vapor is incident at a very high glancing angle and reach a length larger than 1-8 µm even though the number of deposited atoms corresponds to the average thickness of 20-30 nm. This suggests that there is a universal growth mechanism for the nanowires grown by HT-GLAD.

  5. Growth of Han migrants at high altitude in central Asia.

    PubMed

    Weitz, Charles A; Garruto, Ralph M

    2004-01-01

    Han Chinese of low-altitude descent have been living in Qinghai Province of Western China for at least two millennia. For most of this time they have lived at elevations under 2,500 m. However, during the last four decades an increasing number of Han have moved into high-altitude towns at elevations over 3,000 m, and some above 4,000 m. There are now sufficient numbers of Han descendants who have been born and raised at high altitude to allow a comparison of their morphological and physiological growth patterns with low-altitude Han to detect the effect of hypoxia. The field study reported here was conducted by collaborating Chinese and American researchers over a 6-year period, and included 1,227 Han living at high altitude in Qinghai and at low altitude near Beijing. This study demonstrates that Han born and raised at high altitude are smaller and lighter than those at low altitude-particularly as children and adolescents. Slower growth at high altitude may be a consequence of hypoxia, but it also corresponds to poorer economic conditions in rural Qinghai Province, and thus may reflect nutritional inadequacies. Differences in altitude and/or nutrition do not seem to affect thorax dimensions, since, relative to stature, chest dimensions are similar at both high and low altitudes. Nevertheless, lung volumes are higher among Han at high altitude, possibly reflecting the influence of hypoxia on alveolar growth. The hematological values of Han growing up at 3,200 m are not different from those at low altitude-an unusual finding relative to other low-altitude groups that may reflect population differences in response to hypoxia. At 3,800 m and 4,300 m, however, Han show elevated hemoglobin relative to Han at low altitude.

  6. Increased Relative Calcification, Shell Dissolution and Maintained Larval Growth in Mussel (Mytilus edulis) Larvae Exposed to Acidified Under-Saturated Seawater

    NASA Astrophysics Data System (ADS)

    Ventura, A.; Dupont, S. T.; Schulz, S.

    2016-02-01

    Ocean acidification (OA) is known to affect bivalve early life-stages. It is often assumed that aragonite saturation state (Ωa) is the main driver of the biological response. However saturation state of different CaCO3 forms is not the main driver of most physiological processes and pH/pCO2 are playing an overarching role (e.g. acid-base regulation). The aim of our study was to investigate the effects of a wide range of seawater pH on different physiological parameters (e. g. calcification; growth) of blue mussel (Mytilus edulis) developing larvae in order to identify a physiological tipping point beyond which they are no longer capable of carrying out those functions necessary to their survival and recruitment into the adult population. Our results confirmed that increasing seawater acidity and decreasing saturation state increases larval mortality rate and the percentage of abnormally developing larvae. No larvae reared at pHT ≈ 7.1 were able to reach the D-shell veliger stage and their development appeared to be arrested at the trochophore stage. However - despite morphological shell abnormalities - larvae were capable of reaching the D-shell stage when reared at pHT ≈ 7.35 and normally D-shaped larvae were observed in all the remaining treatments (pH ≈ 7.6, 7.85 and 8.1) including in under-saturated seawater with Ωa as low as 0.75 ± 0.03 (mean ± SE). Growth rate of these larvae was not affected by lower pHT despite potential increased energy costs associated with compensatory calcification in response to increased shell dissolution. Overall, our results suggest a shift in energy allocation toward growth in larvae exposed to ocean acidification.

  7. Morphometric study of ovarian follicular growth during the estrous cycle of the laboratory-maintained Indian desert gerbil, Meriones hurrianae (Jerdon).

    PubMed

    Saidapur, S K; Kamath, S R

    1993-01-01

    The pattern of changes in the population of healthy and regressing follicles in relation to the estrous cycle, was studied in the recently domesticated desert gerbil, Meriones hurrianae, which exhibits a longer cycle (proestrus: 1.5 days; estrus: 1 day; metestrus: 1.5 days; diestrus: 3 days). As the granulosa cell layers were not distinct, the follicles were classified on the basis of their morphology and size (group I: small preantral follicles; group II: large preantral follicles; group III: small antral follicles; group IV: medium-sized antral follicles; group V: large-sized follicles; group VI: Graafian follicles). Regressing follicles were classified likewise. Five animals were used for each stage of the cycle. One ovary from each gerbil was serially cut and stained with hematoxylin-eosin. Healthy and regressing follicles were found throughout the cycle. The follicular development occurred typically in a biphasic manner. In phase A, in which follicles reach the antral stage, the growth of oocytes and follicles is linearly correlated, whereas, in phase B, oocyte size remains stationary while follicle size increases due to accumulation of antral fluid. However, oocyte growth and nucleus growth are positively and linearly correlated (r = 0.74). The healthy follicles under 260 microns (groups I, II) do not fluctuate in the ovary of cyclic gerbils, whereas follicles in group III (261-350 microns) increase significantly (p < 0.05) at estrus and those of group IV in diestrus. Further, healthy group III follicles are reduced in diestrus while regressing follicles in group III increase. These findings thus suggest that the antral follicles are rescued from atresia at estrus.(ABSTRACT TRUNCATED AT 250 WORDS)

  8. Platelet-Derived Growth Factor-BB Protects Mesenchymal Stem Cells (MSCs) Derived From Immune Thrombocytopenia Patients Against Apoptosis and Senescence and Maintains MSC-Mediated Immunosuppression.

    PubMed

    Zhang, Jia-Min; Feng, Fei-Er; Wang, Qian-Ming; Zhu, Xiao-Lu; Fu, Hai-Xia; Xu, Lan-Ping; Liu, Kai-Yan; Huang, Xiao-Jun; Zhang, Xiao-Hui

    2016-12-01

    : Immune thrombocytopenia (ITP) is characterized by platelet destruction and megakaryocyte dysfunction. Mesenchymal stem cells (MSCs) from ITP patients (MSC-ITP) do not exhibit conventional proliferative abilities and thus exhibit defects in immunoregulation, suggesting that MSC impairment might be a mechanism involved in ITP. Platelet-derived growth factor (PDGF) improves growth and survival in various cell types. Moreover, PDGF promotes MSC proliferation. The aim of the present study was to analyze the effects of PDGF-BB on MSC-ITP. We showed that MSC-ITP expanded more slowly and appeared flattened and larger. MSC-ITP exhibited increased apoptosis and senescence compared with controls. Both the intrinsic and extrinsic pathways account for the enhanced apoptosis. P53 and p21 expression were upregulated in MSC-ITP, but inhibition of p53 with pifithrin-α markedly inhibited apoptosis and senescence. Furthermore, MSCs from ITP patients showed a lower capacity for inhibiting the proliferation of activated T cells inducing regulatory T cells (Tregs) and suppressing the synthesis of anti-glycoprotein (GP)IIb-IIIa antibodies. PDGF-BB treatment significantly decreased the expression of p53 and p21 and increased survivin expression in MSC-ITP. In addition, the apoptotic rate and number of senescent cells in ITP MSCs were reduced. Their impaired ability for inhibiting activated T cells, inducing Tregs, and suppressing the synthesis of anti-GPIIb-IIIa antibodies was restored after PDGF-BB treatment. In conclusion, we have demonstrated that PDGF-BB protects MSCs derived from ITP patients against apoptosis, senescence, and immunomodulatory defects. This protective effect of PDGF-BB is likely mediated via the p53/p21 pathway, thus potentially providing a new therapeutic approach for ITP. Immune thrombocytopenia (ITP) is characterized by platelet destruction and megakaryocyte dysfunction. Platelet-derived growth factor (PDGF) improves growth and survival in various cell types

  9. Polarization-maintaining, high-energy, wavelength-tunable, Er-doped ultrashort pulse fiber laser using carbon-nanotube polyimide film.

    PubMed

    Senoo, Y; Nishizawa, N; Sakakibara, Y; Sumimura, K; Itoga, E; Kataura, H; Itoh, K

    2009-10-26

    A high-energy, wavelength-tunable, all-polarization-maintaining Er-doped ultrashort fiber laser was demonstrated using a polyimide film dispersed with single-wall carbon nanotubes. A variable output coupler and wavelength filter were used in the cavity configuration, and high-power operation was demonstrated. The maximum average power was 12.6 mW and pulse energy was 585 pJ for stable single-pulse operation with an output coupling ratio as high as 98.3%. Wide wavelength-tunable operation at 1532-1562 nm was also demonstrated by controlling the wavelength filter. The RF amplitude noise characteristics were examined in terms of their dependence on output coupling ratio and oscillation wavelength.

  10. Value innovation: the strategic logic of high growth.

    PubMed

    Kim, W C; Mauborgne, R

    1997-01-01

    Why are some companies able to sustain high growth in revenues and profits--and others are not? To answer that question, the authors, both of INSEAD, spent five years studying more than 30 companies around the world. They found that the difference between the high-growth companies and their less successful competitors was in each group's assumptions about strategy. Managers of the less successful companies followed conventional strategic logic. Managers of the high-growth companies followed what the authors call the logic of value innovation. Conventional strategic logic and value innovation differ along the basic dimensions of strategy. Many companies take their industry's conditions as given; value innovators don't. Many companies let competitors set the parameters of their strategic thinking; value innovators do not use rivals as benchmarks. Rather than focus on the differences among customers, value innovators look for what customers value in common. Rather than view opportunities through the lens of existing assets and capabilities, value innovators ask, What if we start anew? The authors tell the story of the French hotelier Accor, which discarded the notion of what a hotel is supposed to look like in order to offer what most customers want: a good night's sleep at a low price. And Virgin Atlantic challenged industry conventions by eliminating first-class service and channeling savings into innovations for business-class passengers. Those companies didn't set out to build advantages over the competition, but they ended up achieving the greatest competitive advantages.

  11. The problematic growth of dust in high-redshift galaxies

    NASA Astrophysics Data System (ADS)

    Ferrara, A.; Viti, S.; Ceccarelli, C.

    2016-11-01

    Dust growth via accretion of gas species has been proposed as the dominant process to increase the amount of dust in galaxies. We show here that this hypothesis encounters severe difficulties that make it unfit to explain the observed UV and IR properties of such systems, particularly at high redshifts. Dust growth in the diffuse ISM phases is hampered by (a) too slow accretion rates, (b) too high dust temperatures, and (c) the Coulomb barrier that effectively blocks accretion. In molecular clouds these problems are largely alleviated. Grains are cold (but not colder than the CMB temperature, TCMB ≈ 20 K at redshift z = 6). However, in dense environments accreted materials form icy water mantles, perhaps with impurities. Mantles are immediately (≲1 yr) photo-desorbed as grains return to the diffuse ISM at the end of the cloud lifetime, thus erasing any memory of the growth. We conclude that dust attenuating stellar light at high-z must be ready-made stardust largely produced in supernova ejecta.

  12. High-power laser float-zone crystal growth

    NASA Astrophysics Data System (ADS)

    Cohen, A.; Brauch, Uwe; Muckenschnabel, J.; Opower, Hans

    1990-10-01

    A float zone crystal growth apparatus was developed. The heat source was a 3.5 kW CO2 Trumpf laser with a long term stability of 2 %. The original laser beam was divided, in the beam delivery system, into three equivalent focusable beams. The vacuum vessel is equipped with two equivalent rotation - translation systems with a maximum translational speed of 1 mm/minute. The vessel is also pierced with five windows, three of which serve the three incoming beams, one for observation with a television camera, one for an optical pyrometer or for direct observation. The three beam windows are protected by a laminar gas curtain. A heat shield system with an after heater is planned, in order to enable growth of high temperature oxides. The system was tested in the growth of small sapphire crystals (0 4 mm) and in the growth of silicon whose dimensions were 0 10 mm x 70 mm. * On leave from the Weizmann Institute, Rehovot, Israel

  13. Effects of high CO2 on growth and metabolism of Arabidopsis seedlings during growth with a constantly limited supply of nitrogen.

    PubMed

    Takatani, Nobuyuki; Ito, Takuro; Kiba, Takatoshi; Mori, Marie; Miyamoto, Tetsuro; Maeda, Shin-Ichi; Omata, Tatsuo

    2014-02-01

    Elevated CO2 has been reported to stimulate plant growth under nitrogen-sufficient conditions, but the effects of CO2 on growth in a constantly nitrogen-limited state, which is relevant to most natural habitats of plants, remain unclear. Here, we maintained Arabidopsis seedlings under such conditions by growing a mutant with reduced nitrate uptake activity on a medium containing nitrate as the sole nitrogen source. Under nitrogen-sufficient conditions (i.e. in the presence of ammonium), growth of shoots and roots of both the wild type (WT) and the mutant was increased approximately 2-fold by elevated CO2. Growth stimulation of shoots and roots by elevated CO2 was observed in the WT growing with nitrate as the sole nitrogen source, but in the mutant grown with nitrate, the high-CO2 conditions stimulated only the growth of roots. In the mutant, elevated CO2 caused well-known symptoms of nitrogen-starved plants, including decreased shoot/root ratio, reduced nitrate content and accumulation of anthocyanin, but also had an increased Chl content in the shoot, which was contradictory to the known effect of nitrogen depletion. A high-CO2-responsive change specific to the mutant was not observed in the levels of the major metabolites, although CO2 responses were observed in the WT and the mutant. These results indicated that elevated CO2 causes nitrogen limitation in the seedlings grown with a constantly limited supply of nitrogen, but the Chl content and the root biomass of the plant increase to enhance the activities of both photosynthesis and nitrogen uptake, while maintaining normal metabolism and response to high CO2.

  14. Effects of High CO2 on Growth and Metabolism of Arabidopsis Seedlings During Growth with a Constantly Limited Supply of Nitrogen

    PubMed Central

    Takatani, Nobuyuki; Ito, Takuro; Kiba, Takatoshi; Mori, Marie; Miyamoto, Tetsuro; Maeda, Shin-ichi; Omata, Tatsuo

    2014-01-01

    Elevated CO2 has been reported to stimulate plant growth under nitrogen-sufficient conditions, but the effects of CO2 on growth in a constantly nitrogen-limited state, which is relevant to most natural habitats of plants, remain unclear. Here, we maintained Arabidopsis seedlings under such conditions by growing a mutant with reduced nitrate uptake activity on a medium containing nitrate as the sole nitrogen source. Under nitrogen-sufficient conditions (i.e. in the presence of ammonium), growth of shoots and roots of both the wild type (WT) and the mutant was increased approximately 2-fold by elevated CO2. Growth stimulation of shoots and roots by elevated CO2 was observed in the WT growing with nitrate as the sole nitrogen source, but in the mutant grown with nitrate, the high-CO2 conditions stimulated only the growth of roots. In the mutant, elevated CO2 caused well-known symptoms of nitrogen-starved plants, including decreased shoot/root ratio, reduced nitrate content and accumulation of anthocyanin, but also had an increased Chl content in the shoot, which was contradictory to the known effect of nitrogen depletion. A high-CO2-responsive change specific to the mutant was not observed in the levels of the major metabolites, although CO2 responses were observed in the WT and the mutant. These results indicated that elevated CO2 causes nitrogen limitation in the seedlings grown with a constantly limited supply of nitrogen, but the Chl content and the root biomass of the plant increase to enhance the activities of both photosynthesis and nitrogen uptake, while maintaining normal metabolism and response to high CO2. PMID:24319077

  15. An In Vitro Procedure for Phenotypic Screening of Growth Parameters and Symbiotic Performances in Lotus corniculatus Cultivars Maintained in Different Nutritional Conditions.

    PubMed

    Valkov, Vladimir Totev; Chiurazzi, Maurizio

    2016-10-13

    The establishment of legumes crops with phenotypic traits that favour their persistence and competitiveness in mixed swards is a pressing task in sustainable agriculture. However, to fully exploit the potential benefits of introducing pasture-based grass-legume systems, an increased scientific knowledge of legume agronomy for screening of favourable traits is needed. We exploited a short-cut phenotypic screening as a preliminary step to characterize the growth capacity of three different Lotus corniculatus cvs cultivated in different nutritional conditions as well as the evaluation of their nodulation capacities. This experimental scheme, developed for legume species amenable to grow on agar plates conditions, may represent a very preliminary step to achieve phenotypic discrimination on different cultivars.

  16. An In Vitro Procedure for Phenotypic Screening of Growth Parameters and Symbiotic Performances in Lotus corniculatus Cultivars Maintained in Different Nutritional Conditions

    PubMed Central

    Valkov, Vladimir Totev; Chiurazzi, Maurizio

    2016-01-01

    The establishment of legumes crops with phenotypic traits that favour their persistence and competitiveness in mixed swards is a pressing task in sustainable agriculture. However, to fully exploit the potential benefits of introducing pasture-based grass-legume systems, an increased scientific knowledge of legume agronomy for screening of favourable traits is needed. We exploited a short-cut phenotypic screening as a preliminary step to characterize the growth capacity of three different Lotus corniculatus cvs cultivated in different nutritional conditions as well as the evaluation of their nodulation capacities. This experimental scheme, developed for legume species amenable to grow on agar plates conditions, may represent a very preliminary step to achieve phenotypic discrimination on different cultivars. PMID:27754365

  17. 3,5-Diiodothyronine in vivo maintains euthyroidal expression of type 2 iodothyronine deiodinase, growth hormone, and thyroid hormone receptor beta1 in the killifish.

    PubMed

    García-G, C; López-Bojorquez, L; Nuñez, J; Valverde-R, C; Orozco, A

    2007-08-01

    Until recently, 3,5-diiodothyronine (3,5-T(2)) has been considered an inactive by-product of triiodothyronine (T(3)) deiodination. However, studies from several laboratories have shown that 3,5-T(2) has specific, nongenomic effects on mitochondrial oxidative capacity and respiration rate that are distinct from those due to T(3). Nevertheless, little is known about the putative genomic effects of 3,5-T(2). We have previously shown that hyperthyroidism induced by supraphysiological doses of 3,5-T(2) inhibits hepatic iodothyronine deiodinase type 2 (D2) activity and lowers mRNA levels in the killifish in the same manner as T(3) and T(4), suggesting a pretranslational effect of 3,5-T(2) (Garcia-G C, Jeziorski MC, Valverde-R C, Orozco A. Gen Comp Endocrinol 135: 201-209, 2004). The question remains as to whether 3,5-T(2) would have effects under conditions similar to those that are physiological for T(3). To this end, intact killifish were rendered hypothyroid by administering methimazole. Groups of hypothyroid animals simultaneously received 30 nM of either T(3), reverse T(3), or 3,5-T(2). Under these conditions, we expected that, if it were bioactive, 3,5-T(2) would mimic T(3) and thus reverse the compensatory upregulation of D2 and tyroid receptor beta1 and downregulation of growth hormone that characterize hypothyroidism. Our results demonstrate that 3,5-T(2) is indeed bioactive, reversing both hepatic D2 and growth hormone responses during a hypothyroidal state. Furthermore, we observed that 3,5-T(2) and T(3) recruit two distinct populations of transcription factors to typical palindromic and DR4 thyroid hormone response elements. Taken together, these results add further evidence to support the notion that 3,5-T(2) is a bioactive iodothyronine.

  18. Partial root-zone drying and conventional deficit irrigation applied during the whole berry growth maintain yield and berry quality in 'Crimson Seedless' table grapes

    NASA Astrophysics Data System (ADS)

    Pérez-Pastor, Alejandro; Domingo, Rafael; De la Rosa, Jose M.°; Rosario Conesa Saura, M.°

    2016-04-01

    To compare the effects of partial root-zone drying and conventional deficit irrigation applied during post-veraison and the whole berry growth on water relations, yield and berry quality, one experiment was conducted in a commercial vineyard of 'Crimson Seedless' table grapes. Five irrigation treatments were imposed: (i) Control (CTL) irrigated to 110% of crop evapotranspiration (ETc), (ii) regulated deficit irrigation (RDI) irrigated at 50% of CTL during the non- critical period of post-verasion, (iii) continuous deficit irrigation (DIc), irrigated at 50% of CTL throughout the whole berry growing season, (iv) partial root-zone drying (PRD), irrigated similar to RDI, but alternating the irrigation applied in the dry side every 10-14 days; and (v) continuous partial root-zone drying (PRDc), irrigated as DIc but alternating the irrigation in the dry side every 10-14 days. RDI and PRD received 24% and 28% less water than CTL, respectively. These reductions were higher in DIc and PRDc (65% and 53%, respectively). Total yield was not affected by any DI strategy. Only significantly lower values were observed in the weight and height's berries in respect to CTL. However, the colour parameters evaluated increased in all DI treatments, being slightly higher in DIc and PRDc compared with RDI and PRD. In addition, total soluble solids (TSS) were significantly higher in DIc, compared to other irrigated counterparts. Our findings showed that the application of water deficit during the whole berry growth through the use of DIc and PRDc, can be considered for irrigation scheduling in 'Crimson Seedless' table grapes. Acknowledgements This work has been funded by the European Union LIFE+ project IRRIMAN (LIFE13 ENV/ES/000539).

  19. High nitrogen pressure solution growth of GaN

    NASA Astrophysics Data System (ADS)

    Bockowski, Michal

    2014-10-01

    Results of GaN growth from gallium solution under high nitrogen pressure are presented. Basic of the high nitrogen pressure solution (HNPS) growth method is described. A new approach of seeded growth, multi-feed seed (MFS) configuration, is demonstrated. The use of two kinds of seeds: free-standing hydride vapor phase epitaxy GaN (HVPE-GaN) obtained from metal organic chemical vapor deposition (MOCVD)-GaN/sapphire templates and free-standing HVPE-GaN obtained from the ammonothermally grown GaN crystals, is shown. Depending on the seeds’ structural quality, the differences in the structural properties of pressure grown material are demonstrated and analyzed. The role and influence of impurities, like oxygen and magnesium, on GaN crystals grown from gallium solution in the MFS configuration is presented. The properties of differently doped GaN crystals are discussed. An application of the pressure grown GaN crystals as substrates for electronic and optoelectronic devices is reported.

  20. A Microchip for High-throughput Axon Growth Drug Screening

    PubMed Central

    Kim, Hyun Soo; Jeong, Sehoon; Koo, Chiwan; Han, Arum; Park, Jaewon

    2016-01-01

    It has been recently known that not only the presence of inhibitory molecules associated with myelin but also the reduced growth capability of the axons limit mature central nervous system (CNS) axonal regeneration after injury. Conventional axon growth studies are typically conducted using multi-well cell culture plates that are very challenging to investigate localized effects of drugs and limited to low throughput. Unfortunately, there is currently no other in vitro tools that allow investigating localized axonal responses to biomolecules in high-throughput for screening potential drugs that might promote axonal growth. We have developed a compartmentalized neuron culture platform enabling localized biomolecular treatments in parallel to axons that are physically and fluidically isolated from their neuronal somata. The 24 axon compartments in the developed platform are designed to perform four sets of six different localized biomolecular treatments simultaneously on a single device. In addition, the novel microfluidic configuration allows culture medium of 24 axon compartments to be replenished altogether by a single aspiration process, making high-throughput drug screening a reality. PMID:27928514

  1. Bulge Growth Through Disc Instabilities in High-Redshift Galaxies

    NASA Astrophysics Data System (ADS)

    Bournaud, Frédéric

    The role of disc instabilities, such as bars and spiral arms, and the associated resonances, in growing bulges in the inner regions of disc galaxies have long been studied in the low-redshift nearby Universe. There it has long been probed observationally, in particular through peanut-shaped bulges (Chap. 14 10.1007/978-3-319-19378-6_14"). This secular growth of bulges in modern disc galaxies is driven by weak, non-axisymmetric instabilities: it mostly produces pseudobulges at slow rates and with long star-formation timescales. Disc instabilities at high redshift (z > 1) in moderate-mass to massive galaxies (1010 to a few 1011 M⊙ of stars) are very different from those found in modern spiral galaxies. High-redshift discs are globally unstable and fragment into giant clumps containing 108-9 M⊙ of gas and stars each, which results in highly irregular galaxy morphologies. The clumps and other features associated to the violent instability drive disc evolution and bulge growth through various mechanisms on short timescales. The giant clumps can migrate inward and coalesce into the bulge in a few 108 years. The instability in the very turbulent media drives intense gas inflows toward the bulge and nuclear region. Thick discs and supermassive black holes can grow concurrently as a result of the violent instability. This chapter reviews the properties of high-redshift disc instabilities, the evolution of giant clumps and other features associated to the instability, and the resulting growth of bulges and associated sub-galactic components.

  2. Comparative proteome approach demonstrates that platelet-derived growth factor C and D efficiently induce proliferation while maintaining multipotency of hMSCs

    SciTech Connect

    Sotoca, Ana M.; Roelofs-Hendriks, Jose; Boeren, Sjef; Kraan, Peter M. van der; Vervoort, Jacques; Zoelen, Everardus J.J. van; Piek, Ester

    2013-10-15

    This is the first study that comprehensively describes the effects of the platelet-derived growth factor (PDGF) isoforms C and D during in vitro expansion of human mesenchymal stem cells (hMSCs). Our results show that PDGFs can enhance proliferation of hMSCs without affecting their multipotency. It is of great value to culture and expand hMSCs in a safe and effective manner without losing their multipotency for manipulation and further development of cell-based therapies. Moreover, differential effects of PDGF isoforms have been observed on lineage-specific differentiation induced by BMP2 and Vitamin D3. Based on label-free LC-based quantitative proteomics approach we have furthermore identified specific pathways induced by PDGFs during the proliferation process, showing the importance of bioinformatics tools to study cell function. - Highlights: • PDGFs (C and D) significantly increased the number of multipotent undifferentiated hMSCs. • Enhanced proliferation did not impair the ability to undergo lineage-specific differentiation. • Proteomic analysis confirmed the overall signatures of the ‘intact’ cells.

  3. Ex vivo cultures of glioblastoma in three-dimensional hydrogel maintain the original tumor growth behavior and are suitable for preclinical drug and radiation sensitivity screening

    SciTech Connect

    Jiguet Jiglaire, Carine; Baeza-Kallee, Nathalie; Denicolaï, Emilie; Barets, Doriane; Metellus, Philippe; and others

    2014-02-15

    Identification of new drugs and predicting drug response are major challenges in oncology, especially for brain tumors, because total surgical resection is difficult and radiation therapy or chemotherapy is often ineffective. With the aim of developing a culture system close to in vivo conditions for testing new drugs, we characterized an ex vivo three-dimensional culture system based on a hyaluronic acid-rich hydrogel and compared it with classical two-dimensional culture conditions. U87-MG glioblastoma cells and seven primary cell cultures of human glioblastomas were subjected to radiation therapy and chemotherapy drugs. It appears that 3D hydrogel preserves the original cancer growth behavior and enables assessment of the sensitivity of malignant gliomas to radiation and drugs with regard to inter-tumoral heterogeneity of therapeutic response. It could be used for preclinical assessment of new therapies. - Highlights: • We have compared primary glioblastoma cell culture in a 2D versus 3D-matrix system. • In 3D morphology, organization and markers better recapitulate the original tumor. • 3D-matrix culture might represent a relevant system for more accurate drug screening.

  4. Rare Sugar Syrup Containing d-Allulose but Not High-Fructose Corn Syrup Maintains Glucose Tolerance and Insulin Sensitivity Partly via Hepatic Glucokinase Translocation in Wistar Rats.

    PubMed

    Shintani, Tomoya; Yamada, Takako; Hayashi, Noriko; Iida, Tetsuo; Nagata, Yasuo; Ozaki, Nobuaki; Toyoda, Yukiyasu

    2017-04-05

    Ingestion of high-fructose corn syrup (HFCS) is associated with the risk of both diabetes and obesity. Rare sugar syrup (RSS) has been developed by alkaline isomerization of HFCS and has anti-obesity and anti-diabetic effects. However, the influence of RSS on glucose metabolism has not been explored. We investigated whether long-term administration of RSS maintains glucose tolerance and whether the underlying mechanism involves hepatic glucokinase translocation. Wistar rats were administered water, RSS, or HFCS in drinking water for 10 weeks and then evaluated for glucose tolerance, insulin tolerance, liver glycogen content, and subcellular distribution of liver glucokinase. RSS significantly suppressed body weight gain and abdominal fat mass (p < 0.05). The glucose tolerance test revealed significantly higher blood glucose levels in the HFCS group compared to the water group, whereas the RSS group had significantly lower blood glucose levels from 90 to 180 min (p < 0.05). At 30, 60, and 90 min, the levels of insulin in the RSS group were significantly lower than those in the water group (p < 0.05). The amount of hepatic glycogen was more than 3 times higher in the RSS group than that in the other groups. After glucose loading, the nuclear export of glucokinase was significantly increased in the RSS group compared to the water group. These results imply that RSS maintains glucose tolerance and insulin sensitivity, at least partly, by enhancing nuclear export of hepatic glucokinase.

  5. Randomised comparison of diets for maintaining obese subjects' weight after major weight loss: ad lib, low fat, high carbohydrate diet v fixed energy intake.

    PubMed Central

    Toubro, S.; Astrup, A.

    1997-01-01

    OBJECTIVES: To compare importance of rate of initial weight loss for long term outcome in obese patients and to compare efficacy of two different weight maintenance programmes. DESIGN: Subjects were randomised to either rapid or slow initial weight loss. Completing patients were re-randomised to one year weight maintenance programme of ad lib diet or fixed energy intake diet. Patients were followed up one year later. SETTING: University research department in Copenhagen, Denmark. SUBJECTS: 43 (41 women) obese adults (body mass index 27-40) who were otherwise healthy living in or around Copenhagen. INTERVENTIONS: 8 weeks of low energy diet (2 MJ/day) or 17 weeks of conventional diet (5 MJ/day), both supported by an anorectic compound (ephedrine 20 mg and caffeine 200 mg thrice daily); one year weight maintenance programme of ad lib, low fat, high carbohydrate diet or fixed energy intake diet (< or = 7.8 MJ/day), both with reinforcement sessions 2-3 times monthly. MAIN OUTCOME MEASURES: Mean initial weight loss and proportion of patients maintaining a weight loss of > 5 kg at follow up. RESULTS: Mean initial weight loss was 12.6 kg (95% confidence interval 10.9 to 14.3 kg) in rapid weight loss group and 12.6 (9.9 to 15.3) kg in conventional diet group. Rate of initial weight loss had no effect on weight maintenance after 6 or 12 months of weight maintenance or at follow up. After weight maintenance programme, the ad lib group had maintained 13.2 (8.1 to 18.3) kg of the initial weight loss of 13.5 (11.4 to 15.5) kg, and the fixed energy intake group had maintained 9.7 (6.1 to 13.3) kg of the initial 13.8 (11.8 to 15.7) kg weight loss (group difference 3.5 (-2.4 to 9.3) kg). Regained weight at follow up was greater in fixed energy intake group than in ad lib group (11.3 (7.1 to 15.5) kg v 5.4 (2.3 to 8.6) kg, group difference 5.9 (0.7 to 11.1) kg, P < 0.03). At follow up, 65% of ad lib group and 40% of fixed energy intake group had maintained a weight loss of > 5 kg (P

  6. Cultivating a Growth Mindset in Students at a High-Achieving High School

    ERIC Educational Resources Information Center

    Fegley, Alan D.

    2010-01-01

    The purpose of this EPP is to develop a plan for changing the mindset of a large number of Haddonfield Memorial High School (HMHS) students from a fixed mindset to a growth mindset. HMHS is by most conventional measures a high performing school. Typically 100% of the students graduate with 96% of the students attending two or four year colleges…

  7. The growth efficiency of high-redshift black holes

    NASA Astrophysics Data System (ADS)

    Pacucci, Fabio; Volonteri, Marta; Ferrara, Andrea

    2015-09-01

    The observational evidence that Super-Massive Black Holes (M• ˜ 109-10 M⊙) are already in place less than 1 Gyr after the big bang poses stringent time constraints on the growth efficiency of their seeds. Among proposed possibilities, the formation of massive (˜103-6 M⊙) seeds and/or the occurrence of super-Eddington (dot{M}>dot{M}_{Edd}) accretion episodes may contribute to the solution of this problem. In this work, using a set of astrophysically motivated initial conditions, we analytically and numerically investigate the accretion flow on to high-redshift (z ˜ 10) black holes to understand the physical requirements favouring rapid and efficient growth. Our model identifies a `feeding-dominated' accretion regime and a `feedback-limited' one, the latter being characterized by intermittent (duty cycles D ≲ 0.5) and inefficient growth, with recurring outflow episodes. We find that low-mass seeds (≲103-4 M⊙) evolve in the feedback-limited regime, while more massive seeds (≳105-6 M⊙) grow very rapidly as they are found in the feeding-dominated regime. In addition to the standard accretion model with a fixed matter-energy conversion factor (ɛ = 0.1), we have also explored slim disc models, appropriate for super-Eddington accretion, where radiation is trapped in the disc and the radiative efficiency is reduced (ɛ ≲ 0.04), which may ensure a continuous growth with dot{M} ≫ dot{M}_{Edd} (up to {˜ } 300 dot{M}_{Edd} in our simulations). Under these conditions, outflows play a negligible role and a black hole can accrete 80-100 per cent of the gas mass of the host halo (˜107 M⊙) in ˜10 Myr, while in feedback-limited systems we predict that black holes can accrete only up to ˜15 per cent of the available mass.

  8. Stationary structure of a high-frequency discharge maintained by a distributed electromagnetic source in the presence of an external magnetic field

    SciTech Connect

    Es'kin, V. A.; Kudrin, A. V.

    2010-04-15

    The stationary structure of an axisymmetric high-frequency discharge maintained by a given source in an external dc magnetic field is investigated. The source is assumed to be a current wave that travels over the discharge tube surface in the direction of the external magnetic field. The source current has a single azimuthal component and its frequency belongs to the lower hybrid range. The main emphasis is placed on the special case where the electron heat conduction length across the external magnetic field exceeds considerably the tube radius. The dependences of discharge plasma parameters on the current amplitude and propagation constant along the tube have been found for this case. The results of numerical calculations of the distributions of the field and the power of the Joule loss in a discharge are presented.

  9. High-power near-infrared linearly-polarized supercontinuum generation in a polarization-maintaining Yb-doped fiber amplifier.

    PubMed

    Zhang, Bin; Jin, Aijun; Ma, Pengfei; Chen, Shengping; Hou, Jing

    2015-11-02

    We report an all-fiber linearly-polarized (LP) supercontinuum (SC) source with high average power generated in a polarization-maintaining (PM) master-oscillation power-amplifier (MOPA). The experimental configuration comprises an LP picosecond pulsed laser and three PM Yd-doped fiber amplifiers (YDFA). The output has the average power of 124.8 W with the spectrum covering from 850 to 1900 nm. The measured polarization extinction ratio (PER) of the whole SC source is about 85% which verifies the SC an LP source. This work is, to our best knowledge, the highest output average power of an LP SC source that ever reported. The influence of PM fiber splicing method on the LP SC property is investigated by splicing the PM fibers with slow axis parallel or perpendicularly aligned, and also an LP SC with low output power is demonstrated.

  10. Normal bone growth requires optimal estrogen levels: negative effects of both high and low dose estrogen on the number of growth plate chondrocytes.

    PubMed

    Takano, Hiroyuki; Aizawa, Toshimi; Irie, Taichi; Itoi, Eiji; Kokubun, Shoichi; Roach, Helmtrud I

    2008-03-01

    Endochondral bone formation at epiphyseal growth plate consists of the synchronized processes of chondrogenesis and cartilage ossification. Estrogen, the major female sex hormone, plays an important role in this process, particularly during the pubertal growth spurt. However, its effects on the growth plate are not completely understood. The aims of this study were to clarify the effects of estrogen on the kinetics of chondrocytes in the growth plates of 10- to 25-week-old female rabbits by studying the effects of ovariectomy or high-dose administration of estrogen on the balance between cell proliferation and death. Forty-eight Japanese white rabbits were divided into three groups: sham operated, ovariectomized, or ovariectomized with subsequent weekly injection of high dose estrogen from 10 weeks. The chondrocyte kinetics was investigated by histomorphometry and immunohistochemistry, using antibodies for caspase-3, a marker of apoptosis, and for proliferating cell nuclear antigen. Both ovariectomized and estrogen-injected rabbits showed a declination of the chondrocyte number although the latter animals indicated a more dramatic effect. Estrogen-injected rabbits showed a decrease in the cell proliferating ability together with an increase in chondrocytes undergoing apoptosis while ovariectomy mainly reduced the cell proliferating ability. Given the known importance of estrogen for bone growth, one would expect that ovariectomy and high-dose administration of estrogen would have opposite effects. However, the present study indicated that both low and high concentration had a similar effect: a decrease in the chondrocyte number compared with control, suggesting that estrogen has to be maintained within a narrow range for optimal bone growth.

  11. High-density fluids and the growth of monocrystalline diamonds

    NASA Astrophysics Data System (ADS)

    Weiss, Y.; Kiflawi, I.; Davies, N.; Navon, O.

    2014-09-01

    The chemical nature and composition of the growth medium of monocrystalline (MC) diamonds is still a matter of debate, partially because carbonate-bearing high-density fluids (HDFs) that are common in fibrous diamonds have not been found in MC diamonds. Here we report the first finding of HDF microinclusions in a MC octahedral diamond from Finsch, South Africa and in the MC octahedral core of a coated diamond from Kankan, Guinea; both diamonds carry nitrogen in B-centers. Numerous microinclusions in diamond Finsch_2a_cap1 are restricted to two thin layers parallel to the (1 1 1) face, ∼20 and 200 μm from the diamond rim. Low-Mg carbonatitic HDFs are found along the inner layer while the outer layer trapped saline compositions. The major and trace element compositions of the inclusions and their infrared spectra are highly similar to those of microinclusions found in fibrous diamonds. A few isolated microinclusions of saline compositions are scattered around a sulfide inclusion in the center of the octahedral core of diamond ON-KAN-383. This evidence for the involvement of oxidized fluids in the formation of MC diamonds adds to previous reports on the antiquity of HDFs in fibrous diamonds, the presence of carbonate and halide phases in inclusions in MC diamonds and the similarity of trace element pattern of a MC diamond to those of low-Mg carbonatitic HDF in fibrous diamonds. In addition, we show that the interaction of HDFs with depleted garnets can produce sinusoidal REE patterns which are one of the primary features of lherzolitic and harzburgitic garnet inclusions in MC diamonds. Together, these observations suggest that HDFs are involved in the formation of many types of diamonds from the Archaean to the Phanerozoic. HDFs are trapped in large quantities during rapid, fibrous growth, but must also be present during the growth of many MC diamonds.

  12. Modeling high speed growth of large rods of cesium iodide crystals by edge-defined film-fed growth (EFG)

    NASA Astrophysics Data System (ADS)

    Yeckel, Andrew

    2016-09-01

    A thermocapillary model of edge-defined film-fed growth (EFG) is developed to analyze an experimental system for high speed growth of cesium iodide as a model system for halide scintillator production. The model simulates heat transfer and fluid dynamics in the die, melt, and crystal under conditions of steady growth. Appropriate mass, force, and energy balances are used to compute self-consistent shapes of the growth interface and melt-vapor meniscus. The model is applied to study the effects of growth rate, die geometry, and furnace heat transfer on the limits of system operability. An inverse problem formulation is used to seek operable states at high growth rates by adjusting the overall temperature level and thermal gradient in the furnace. The model predicts that steady growth is feasible at rates greater than 20 mm/h for crystals up to 18 mm in diameter under reasonable furnace gradients.

  13. Growth of highly strained CeO2 ultrathin films

    DOE PAGES

    Shi, Yezhou; Lee, Sang Chul; Monti, Matteo; ...

    2016-11-07

    Large biaxial strain is a promising route to tune the functionalities of oxide thin films. However, large strain is often not fully realized due to the formation of misfit dislocations at the film/substrate interface. In this work, we examine the growth of strained ceria (CeO2) thin films on (001)-oriented single crystal yttria-stabilized zirconia (YSZ) via pulsed-laser deposition. By varying the film thickness systematically between 1 and 430 nm, we demonstrate that ultrathin ceria films are coherently strained to the YSZ substrate for thicknesses up to 2.7 nm, despite the large lattice mismatch (~5%). The coherency is confirmed by both X-raymore » diffraction and high-resolution transmission electron microscopy. This thickness is several times greater than the predicted equilibrium critical thickness. Partial strain relaxation is achieved by forming semirelaxed surface islands rather than by directly nucleating dislocations. In situ reflective high-energy electron diffraction during growth confirms the transition from 2-D (layer-by-layer) to 3-D (island) at a film thickness of ~1 nm, which is further supported by atomic force microscopy. We propose that dislocations likely nucleate near the surface islands and glide to the film/substrate interface, as evidenced by the presence of 60° dislocations. Finally, an improved understanding of growing oxide thin films with a large misfit lays the foundation to systematically explore the impact of strain and dislocations on properties such as ionic transport and redox chemistry.« less

  14. High Thermal Conducting Boron Arsenide: Crystal Growth and Characterization

    NASA Astrophysics Data System (ADS)

    Lv, Bing; Lan, Yucheng; Wang, Xiqu; Zhang, Qian; Hu, Yongjie; Jacobson, Allan J.; Broido, David; Chen, Gang; Ren, Zhifeng; Chu, Ching-Wu

    2015-03-01

    Intrigued by recent calculations [Phys. Rev. Lett. 111, 025901(2013)] which predict a remarkably high thermal conductivity of ~ 2,000 Wm-1K-1 , comparable to that of diamond, in cubic boron arsenide (BAs) crystals, we have succeeded in synthesizing single crystals of BAs with a zinc blende structure and lattice parameters of a = 4.7830(7) Å characterized by X-ray single crystal diffraction and transmission electron microscopy (TEM). A relatively high thermal conductivity is obtained but still smaller than the predicted value. We attribute the difference of thermal conductivity value to the defect scattering associated with crystal twinning and As vacancies, verified both from experimental evidence and theoretical calculations. The predicted super-thermal-conductivity may be achieved in BAs single crystals with further improvement of crystal growth by removing the defects. Lawrence Berkeley National Laboratory, Berkeley California 94720.

  15. High Speed Crystal Growth by Q-switched Laser Melting

    NASA Technical Reports Server (NTRS)

    Cullis, A. G.

    1984-01-01

    The modification of the structural and electrical properties of semiconductors short radiation pulses obtained from Q-switched lasers is described. These modifications are accomplished by high heating and cooling rates. This processing revealed novel crystal growth and high speed resolidification phenomena. The behavior of semiconductor Si is analyzed. The annealing process typically employs short pulses of radiation in or near the visible region of the spectrum. The Q-switched ruby and Nd-YAG lasers are commonly used and these are sometimes mode locked to reduce the pulse length still further. Material to be annealed can be processed with a single large area radiation spot. Alternatively, a small radiation spot size can be used and a large sample area is covered by overlapping irradiated regions.

  16. Developing Seeds of Ricinus communis L., When Detached and Maintained in an Atmosphere of High Relative Humidity, Switch to a Germinative Mode without the Requirement for Complete Desiccation.

    PubMed

    Kermode, A R; Bewley, J D

    1989-06-01

    Immature seeds of castor bean (Ricinus communis) removed from the capsule at 25 to 40 days after pollination (25-40 DAP) and placed in an atmosphere of high relative humidity undergo limited water loss, and germinate upon subsequent return to full hydration. This switch from a developmental to a germinative/growth mode at 40 DAP is reflected in a change in the types of proteins being synthesized in the endosperm; after partial drying, developmental protein synthesis ceases and germinative/growth-related proteins are produced. The nature and timing of these protein synthetic changes elicited upon imbibition are identical to those following premature desiccation/rehydration of 30 and 40 DAP seeds and upon imbibition of the mature dry seed. Enzymes involved in postgerminative reserve mobilization (l-leucyl-beta-naphthylamidase and isocitrate lyase) are induced upon imbibition, following partial drying at 40 DAP, to levels attained in the endosperms of germinated mature, and prematurely dried/rehydrated, seeds. The changes in protein synthesis resulting from partial drying are effected at the transcriptional and post-transcriptional level. Upon return to full hydration some new (i.e. germination and growth-related) mRNAs are synthesized, while others (associated with development) present in the partially dried endosperm decline. Thus developing seeds of castor bean do not have to experience substantial (whole seed) water loss to acquire the ability to germinate and grow upon subsequent imbibition. Seed detachment from the mother plant alone is not sufficient to elicit a switch to germination and growth processes. However, the length of time of detachment from the mother plant, in combination with some water loss may interact to elicit the "switch" from development to germination.

  17. Distinct Ca2+ channels maintain a high motility state of the sperm that may be needed for penetration of egg jelly of the newt, Cynops pyrrhogaster.

    PubMed

    Takahashi, Tomoe; Kutsuzawa, Megumi; Shiba, Kogiku; Takayama-Watanabe, Eriko; Inaba, Kazuo; Watanabe, Akihiko

    2013-09-01

    Activation state of sperm motility named "hyperactivation" enables mammalian sperm to progress through the oviductal matrix, although a similar state of sperm motility is unknown in non-mammalian vertebrates at fertilization. Here, we found a high motility state of the sperm in the newt Cynops pyrrhogaster. It was predominantly caused in egg jelly extract (JE) and characterized by a high wave velocity of the undulating membrane (UM) that was significantly higher at the posterior midpiece. An insemination assay suggested that the high motility state might be needed for sperm to penetrate the egg jelly, which is the accumulated oviductal matrix. Specific characteristics of the high motility state were completely abrogated by a high concentration of verapamil, which blocks the L-type and T-type voltage-dependent Ca(2+) channels (VDCCs). Mibefradil, a dominant blocker of T-type VDCCs, suppressed the wave of the UM at the posterior midpiece with separate wave propagation from both the anterior midpiece and the posterior principal piece. In addition, nitrendipine, a dominant L-type VDCC blocker, weakened the wave of the UM, especially in the anterior midpiece. Live Ca(2+) imaging showed that, compared with the intact sperm in the JE, the relative intracellular Ca(2+) level changed especially in the anterior and posterior ends of the midpiece of the blocker-treated sperm. These suggest that different types of Ca(2+) channels mediate the intracellular Ca(2+) level predominantly in the anterior and posterior ends of the midpiece to maintain the high motility state of the newt sperm.

  18. Updated periodic evaluation of standardized neurointensive care shows that it is possible to maintain a high level of favorable outcome even with increasing mean age.

    PubMed

    Lenell, Samuel; Nyholm, Lena; Lewén, Anders; Enblad, Per

    2015-03-01

    Periodic evaluation of neurointensive care (NIC) is important. There is a risk that quality of daily care declines and there may also be unrecognized changes in patient characteristics and management. The aim of this work was to investigate the characteristics and outcome for traumatic brain injury (TBI) patients in the period 2008-2009 in comparison with 1996-1997 and to some extent also with earlier periods. TBI patients 16-79 years old admitted from 2008 to 2009 were selected for the study. Glasgow Coma Scale Motor score at admission (GCS M), radiology, surgery, and outcome (Glasgow Outcome Extended Scale) were collected from Uppsala Traumatic Brain Injury Register. The study included 148 patients (mean age, 45 years). Patients >60 years old increased from 16 % 1996-1997 to 30 % 2008-2009 (p < 0.01). The proportion of GCS M 4-6 were similar, 92 vs. 93 % (NS). In 1996-1997 patients, 73 % had diffuse injury (Marshall classification) compared to 77 % for the 2008-2009 period (NS). More patients underwent surgery during 2008-2009 (43 %) compared to 1996-1997 (32 %, p < 0.05). Good recovery increased and mortality decreased substantially from 1980-1981 to 1987-1988 and to 1996-1997, but then the results were unchanged in the 2008-2009 period, with 73 % favorable outcome and 11 % mortality. Mortality increased in GCS M 6-4, from 2.8 % in 1996-1997 to 10 % in 2008-2009 (p < 0.05); most of the patients that died had aggravating factors, e.g., high age, malignancy. A large-proportion favorable outcome was maintained despite that patients >60 years with poorer prognosis doubled, indicating that the quality of NIC has increased or at least is unchanged. More surgery may have contributed to maintaining the large proportion of favorable outcome. For future improvements, more knowledge about TBI management in the elderly is required.

  19. Will Coral Islands maintain their growth over the next century? A deterministic model of sediment availability at Lady Elliot Island, Great Barrier Reef.

    PubMed

    Hamylton, Sarah

    2014-01-01

    A geomorphic assessment of reef system calcification is conducted for past (3200 Ka to present), present and future (2010-2100) time periods. Reef platform sediment production is estimated at 569 m3 yr-1 using rate laws that express gross community carbonate production as a function of seawater aragonite saturation, community composition and rugosity and incorporating estimates of carbonate removal from the reef system. Key carbonate producers including hard coral, crustose coralline algae and Halimeda are mapped accurately (mean R2 = 0.81). Community net production estimates correspond closely to independent census-based estimates made in-situ (R2 = 0.86). Reef-scale outputs are compared with historic rates of production generated from (i) radiocarbon evidence of island deposition initiation around 3200 years ago, and (ii) island volume calculated from a high resolution island digital elevation model. Contemporary carbonate production rates appear to be remarkably similar to historical values of 573 m3 yr-1. Anticipated future seawater chemistry parameters associated with an RCP8.5 emissions scenario are employed to model rates of net community calcification for the period 2000-2100 on the basis of an inorganic aragonite precipitation law, under the assumption of constant benthic community character. Simulations indicate that carbonate production will decrease linearly to a level of 118 m3 yr-1 by 2100 and that by 2150 aragonite saturation levels may no longer support the positive budgetary status necessary to sustain island accretion. Novel aspects of this assessment include the development of rate law parameters to realistically represent the variable composition of coral reef benthic carbonate producers, incorporation of three dimensional rugosity of the entire reef platform and the coupling of model outputs with both historical radiocarbon dating evidence and forward hydrochemical projections to conduct an assessment of island evolution through time

  20. Rational Water and Nitrogen Management Improves Root Growth, Increases Yield and Maintains Water Use Efficiency of Cotton under Mulch Drip Irrigation

    PubMed Central

    Zhang, Hongzhi; Khan, Aziz; Tan, Daniel K. Y.; Luo, Honghai

    2017-01-01

    There is a need to optimize water-nitrogen (N) applications to increase seed cotton yield and water use efficiency (WUE) under a mulch drip irrigation system. This study evaluated the effects of four water regimes [moderate drip irrigation from the third-leaf to the boll-opening stage (W1), deficit drip irrigation from the third-leaf to the flowering stage and sufficient drip irrigation thereafter (W2), pre-sowing and moderate drip irrigation from the third-leaf to the boll-opening stage (W3), pre-sowing and deficit drip irrigation from the third-leaf to the flowering stage and sufficient drip irrigation thereafter (W4)] and N fertilizer at a rate of 520 kg ha-1 in two dressing ratios [7:3 (N1), 2:8 (N2)] on cotton root morpho-physiological attributes, yield, WUE and the relationship between root distribution and dry matter production. Previous investigations have shown a strong correlation between root activity and water consumption in the 40–120 cm soil layer. The W3 and especially W4 treatments significantly increased root length density (RLD), root volume density (RVD), root mass density (RMD), and root activity in the 40–120 cm soil layer. Cotton RLD, RVD, RMD was decreased by 13.1, 13.3, and 20.8%, respectively, in N2 compared with N1 at 70 days after planting (DAP) in the 0–40 cm soil layer. However, root activity in the 40–120 cm soil layer at 140 DAP was 31.6% higher in N2 than that in N1. Total RMD, RLD and root activity in the 40–120 cm soil were significantly and positively correlated with shoot dry weight. RLD and root activity in the 40–120 cm soil layer was highest in the W4N2 treatments. Therefore increased water consumption in the deep soil layers resulted in increased shoot dry weight, seed cotton yield and WUE. Our data can be used to develop a water-N management strategy for optimal cotton yield and high WUE. PMID:28611817

  1. Rational Water and Nitrogen Management Improves Root Growth, Increases Yield and Maintains Water Use Efficiency of Cotton under Mulch Drip Irrigation.

    PubMed

    Zhang, Hongzhi; Khan, Aziz; Tan, Daniel K Y; Luo, Honghai

    2017-01-01

    There is a need to optimize water-nitrogen (N) applications to increase seed cotton yield and water use efficiency (WUE) under a mulch drip irrigation system. This study evaluated the effects of four water regimes [moderate drip irrigation from the third-leaf to the boll-opening stage (W1), deficit drip irrigation from the third-leaf to the flowering stage and sufficient drip irrigation thereafter (W2), pre-sowing and moderate drip irrigation from the third-leaf to the boll-opening stage (W3), pre-sowing and deficit drip irrigation from the third-leaf to the flowering stage and sufficient drip irrigation thereafter (W4)] and N fertilizer at a rate of 520 kg ha(-1) in two dressing ratios [7:3 (N1), 2:8 (N2)] on cotton root morpho-physiological attributes, yield, WUE and the relationship between root distribution and dry matter production. Previous investigations have shown a strong correlation between root activity and water consumption in the 40-120 cm soil layer. The W3 and especially W4 treatments significantly increased root length density (RLD), root volume density (RVD), root mass density (RMD), and root activity in the 40-120 cm soil layer. Cotton RLD, RVD, RMD was decreased by 13.1, 13.3, and 20.8%, respectively, in N2 compared with N1 at 70 days after planting (DAP) in the 0-40 cm soil layer. However, root activity in the 40-120 cm soil layer at 140 DAP was 31.6% higher in N2 than that in N1. Total RMD, RLD and root activity in the 40-120 cm soil were significantly and positively correlated with shoot dry weight. RLD and root activity in the 40-120 cm soil layer was highest in the W4N2 treatments. Therefore increased water consumption in the deep soil layers resulted in increased shoot dry weight, seed cotton yield and WUE. Our data can be used to develop a water-N management strategy for optimal cotton yield and high WUE.

  2. Will Coral Islands Maintain Their Growth over the Next Century? A Deterministic Model of Sediment Availability at Lady Elliot Island, Great Barrier Reef

    PubMed Central

    Hamylton, Sarah

    2014-01-01

    A geomorphic assessment of reef system calcification is conducted for past (3200 Ka to present), present and future (2010–2100) time periods. Reef platform sediment production is estimated at 569 m3 yr−1 using rate laws that express gross community carbonate production as a function of seawater aragonite saturation, community composition and rugosity and incorporating estimates of carbonate removal from the reef system. Key carbonate producers including hard coral, crustose coralline algae and Halimeda are mapped accurately (mean R2 = 0.81). Community net production estimates correspond closely to independent census-based estimates made in-situ (R2 = 0.86). Reef-scale outputs are compared with historic rates of production generated from (i) radiocarbon evidence of island deposition initiation around 3200 years ago, and (ii) island volume calculated from a high resolution island digital elevation model. Contemporary carbonate production rates appear to be remarkably similar to historical values of 573 m3 yr−1. Anticipated future seawater chemistry parameters associated with an RCP8.5 emissions scenario are employed to model rates of net community calcification for the period 2000–2100 on the basis of an inorganic aragonite precipitation law, under the assumption of constant benthic community character. Simulations indicate that carbonate production will decrease linearly to a level of 118 m3 yr−1 by 2100 and that by 2150 aragonite saturation levels may no longer support the positive budgetary status necessary to sustain island accretion. Novel aspects of this assessment include the development of rate law parameters to realistically represent the variable composition of coral reef benthic carbonate producers, incorporation of three dimensional rugosity of the entire reef platform and the coupling of model outputs with both historical radiocarbon dating evidence and forward hydrochemical projections to conduct an assessment of island evolution

  3. Initial segment Kv2.2 channels mediate a slow delayed rectifier and maintain high frequency action potential firing in medial nucleus of the trapezoid body neurons.

    PubMed

    Johnston, Jamie; Griffin, Sarah J; Baker, Claire; Skrzypiec, Anna; Chernova, Tatanya; Forsythe, Ian D

    2008-07-15

    The medial nucleus of the trapezoid body (MNTB) is specialized for high frequency firing by expression of Kv3 channels, which minimize action potential (AP) duration, and Kv1 channels, which suppress multiple AP firing, during each calyceal giant EPSC. However, the outward K(+) current in MNTB neurons is dominated by another unidentified delayed rectifier. It has slow kinetics and a peak conductance of approximately 37 nS; it is half-activated at -9.2 +/- 2.1 mV and half-inactivated at -35.9 +/- 1.5 mV. It is blocked by several non-specific potassium channel antagonists including quinine (100 microm) and high concentrations of extracellular tetraethylammonium (TEA; IC(50) = 11.8 mM), but no specific antagonists were found. These characteristics are similar to recombinant Kv2-mediated currents. Quantitative RT-PCR showed that Kv2.2 mRNA was much more prevalent than Kv2.1 in the MNTB. A Kv2.2 antibody showed specific staining and Western blots confirmed that it recognized a protein approximately 110 kDa which was absent in brainstem tissue from a Kv2.2 knockout mouse. Confocal imaging showed that Kv2.2 was highly expressed in axon initial segments of MNTB neurons. In the absence of a specific antagonist, Hodgkin-Huxley modelling of voltage-gated conductances showed that Kv2.2 has a minor role during single APs (due to its slow activation) but assists recovery of voltage-gated sodium channels (Nav) from inactivation by hyperpolarizing interspike potentials during repetitive AP firing. Current-clamp recordings during high frequency firing and characterization of Nav inactivation confirmed this hypothesis. We conclude that Kv2.2-containing channels have a distinctive initial segment location and crucial function in maintaining AP amplitude by regulating the interspike potential during high frequency firing.

  4. Effects of high medium pH on growth, metabolism and transport in Saccharomyces cerevisiae.

    PubMed

    Peña, Antonio; Sánchez, Norma Silvia; Álvarez, Helber; Calahorra, Martha; Ramírez, Jorge

    2015-03-01

    Growth of Saccharomyces cerevisiae stopped by maintaining the pH of the medium in a pH-stat at pH 8.0 or 9.0. Studying its main physiological capacities and comparing cells after incubation at pH 6.0 vs. 8.0 or 9.0, we found that (a) fermentation was moderately decreased by high pH and respiration was similar and sensitive to the addition of an uncoupler, (b) ATP and glucose-6-phosphate levels upon glucose addition increased to similar levels and (c) proton pumping and K(+) transport were also not affected; all this indicating that energy mechanisms were preserved. Growth inhibition at high pH was also not due to a significant lower amino acid transport by the cells or incorporation into proteins. The cell cycle stopped at pH 9.0, probably due to an arrest as a result of adjustments needed by the cells to contend with the changes under these conditions, and microarray experiments showed some relevant changes to this response.

  5. Approach for growth of high-quality and large protein crystals.

    PubMed

    Matsumura, Hiroyoshi; Sugiyama, Shigeru; Hirose, Mika; Kakinouchi, Keisuke; Maruyama, Mihoko; Murai, Ryota; Adachi, Hiroaki; Takano, Kazufumi; Murakami, Satoshi; Mori, Yusuke; Inoue, Tsuyoshi

    2011-01-01

    Three crystallization methods for growing large high-quality protein crystals, i.e. crystallization in the presence of a semi-solid agarose gel, top-seeded solution growth (TSSG) and a large-scale hanging-drop method, have previously been presented. In this study the effectiveness of crystallization in the presence of a semi-solid agarose gel has been further evaluated by crystallizing additional proteins in the presence of 2.0% (w/v) agarose gel, resulting in complete gelification with high mechanical strength. In TSSG the seed crystals are hung by a seed holder protruding from the top of the growth vessel to prevent polycrystallization. In the large-scale hanging-drop method, a cut pipette tip was used to maintain large-scale droplets consisting of protein-precipitant solution. Here a novel crystallization method that combines TSSG and the large-scale hanging-drop method is reported. A large and single crystal of lysozyme was obtained by this method.

  6. Poor early growth and high salt intake in Indian infants.

    PubMed

    Genovesi, Simonetta; Antolini, Laura; Orlando, Antonina; Brahmochary, Sujit; De Servi, Alessandra; Capelli, Silvia; Giussani, Marco; Nava, Elisa; Agostoni, Carlo; Gallieni, Maurizio

    2016-11-06

    The influence of feeding patterns on the growth of infants and how salt is included in the diet are unknown in the area of West Bengal, India. A cross-sectional study was carried on 517 infants (median age 6.5 months). Negative Z-scores were observed for all anthropometric parameters. About 72.7% of infants aged 0-6 months received exclusive breastfeeding. In the 6-12-month-old group (n = 235), 91.5% had salt added to foods. In a regression model adjusted for age, a low salt diet resulted a significant factor in increasing weight-for-length and BMI for age z-scores, with increments equal to 0.637 SD (p = 0.037) and 0.650 SD (p = 0.036), respectively. In West Bengal infants showing poor growth, breastfeeding was associated with better anthropometric indexes, but early in life salt is added to their diet. Early life low weight coupled with high salt intake may be a risk factor for arterial hypertension in Indian children.

  7. A Microfluidic, High Throughput Protein Crystal Growth Method for Microgravity

    PubMed Central

    Carruthers Jr, Carl W.; Gerdts, Cory; Johnson, Michael D.; Webb, Paul

    2013-01-01

    The attenuation of sedimentation and convection in microgravity can sometimes decrease irregularities formed during macromolecular crystal growth. Current terrestrial protein crystal growth (PCG) capabilities are very different than those used during the Shuttle era and that are currently on the International Space Station (ISS). The focus of this experiment was to demonstrate the use of a commercial off-the-shelf, high throughput, PCG method in microgravity. Using Protein BioSolutions’ microfluidic Plug Maker™/CrystalCard™ system, we tested the ability to grow crystals of the regulator of glucose metabolism and adipogenesis: peroxisome proliferator-activated receptor gamma (apo-hPPAR-γ LBD), as well as several PCG standards. Overall, we sent 25 CrystalCards™ to the ISS, containing ~10,000 individual microgravity PCG experiments in a 3U NanoRacks NanoLab (1U = 103 cm.). After 70 days on the ISS, our samples were returned with 16 of 25 (64%) microgravity cards having crystals, compared to 12 of 25 (48%) of the ground controls. Encouragingly, there were more apo-hPPAR-γ LBD crystals in the microgravity PCG cards than the 1g controls. These positive results hope to introduce the use of the PCG standard of low sample volume and large experimental density to the microgravity environment and provide new opportunities for macromolecular samples that may crystallize poorly in standard laboratories. PMID:24278480

  8. Microbial growth under a high-pressure CO2 environment

    NASA Astrophysics Data System (ADS)

    Thompson, J. R.; Hernandez, H. H.

    2009-12-01

    Carbon capture and storage (CCS) of CO2 has the potential to significantly reduce the emission of greenhouse gasses associated with fossil fuel combustion. The largest potential for storing captured CO2 in the United Sates is in deep geologic saline formations. Currently, little is known about the effects of CO2 storage on biologically active microbial communities found in the deep earth biosphere. Therefore, to investigate how deep earth microbial communities will be affected by the storage of CO2, we have built a high-pressure microbial growth system in which microbial samples are subjected to a supercritical CO2 (scCO2) environment. Recently we have isolated a microbial consortium that is capable of growth and extracellular matrix production in nutrient media under a supercritical CO2 headspace. This consortium was cultivated from hydrocarbon residues associated with saline formation waters and includes members of the gram-positive Bacillus genus. The cultivation of actively growing cells in an environment containing scCO2 is unexpected based on previous experimental evidence of microbial sterilization attributed to the acidic, desiccating, and solvent-like properties of scCO2. Such microbial consortia have potential for development as (i) biofilm barriers for geological carbon-dioxide sequestration, and as (ii) agents of biocatalysis in environmentally-friendly supercritical (sc) CO2 solvent systems. The discovery that microbes can remain biologically active, and grow, in these environments opens new frontiers for the use of self-regenerating biological systems in engineering applications.

  9. Measurement of plasma density in the discharge maintained in a nonuniform gas flow by a high-power terahertz-wave gyrotron

    SciTech Connect

    Sidorov, A. V.; Razin, S. V.; Golubev, S. V.; Safronova, M. I.; Fokin, A. P.; Luchinin, A. G.; Vodopyanov, A. V.; Glyavin, M. Yu.

    2016-04-15

    We performed measurements of plasma density in a “point-like” discharge, which is generated in a nonuniform flow of a gas (argon) under the action of high-power terahertz gyrotron radiation with a frequency of 0.67 THz, a power of 40 kW, and a pulse duration of 20 μs. The nonuniform flow was produced by injecting the gas to the vacuum chamber through a small hole (0.14 mm in diameter) under a background pressure at a level of 0.01 Torr. The discharge developed and was localized only in a small region of space (about 1 mm) near the gas injection hole, where the pressure was high (close to the atmospheric one) and the breakdown conditions (the “point-like” discharge) were fulfilled. The density of electrons in the discharge was measured by observing the Stark broadening of the atomic radiation line H{sub α} of hydrogen (656.3 nm) which was present in the discharge as a minor admixture. The plasma density in the discharge was equal to about 2 × 10{sup 16} cm{sup −3}, which exceeds the cut-off density for a frequency of 0.67 THz used to maintain the discharge.

  10. 76 FR 30391 - Agency Information Collection Activities; Submission for OMB Review; Comment Request; High Growth...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-25

    ... Activities; Submission for OMB Review; Comment Request; High Growth and Community-Based Job Training Grants... Administration (ETA) sponsored information collection request (ICR) titled, ``High Growth and Community-Based Job... INFORMATION: This information collection request implements reporting requirements for High Growth...

  11. High Yield Chemical Vapor Deposition Growth of High Quality Large-Area AB Stacked Bilayer Graphene

    PubMed Central

    Liu, Lixin; Zhou, Hailong; Cheng, Rui; Yu, Woo Jong; Liu, Yuan; Chen, Yu; Shaw, Jonathan; Zhong, Xing; Huang, Yu; Duan, Xiangfeng

    2012-01-01

    Bernal stacked (AB stacked) bilayer graphene is of significant interest for functional electronic and photonic devices due to the feasibility to continuously tune its band gap with a vertical electrical field. Mechanical exfoliation can be used to produce AB stacked bilayer graphene flakes but typically with the sizes limited to a few micrometers. Chemical vapor deposition (CVD) has been recently explored for the synthesis of bilayer graphene but usually with limited coverage and a mixture of AB and randomly stacked structures. Herein we report a rational approach to produce large-area high quality AB stacked bilayer graphene. We show that the self-limiting effect of graphene growth on Cu foil can be broken by using a high H2/CH4 ratio in a low pressure CVD process to enable the continued growth of bilayer graphene. A high temperature and low pressure nucleation step is found to be critical for the formation of bilayer graphene nuclei with high AB stacking ratio. A rational design of a two-step CVD process is developed for the growth of bilayer graphene with high AB stacking ratio (up to 90 %) and high coverage (up to 99 %). The electrical transport studies demonstrated that devices made of the as-grown bilayer graphene exhibit typical characteristics of AB stacked bilayer graphene with the highest carrier mobility exceeding 4,000 cm2/V·s at room temperature, comparable to that of the exfoliated bilayer graphene. PMID:22906199

  12. Temporal variability in detritus resource maintains diversity of bacterial communities

    NASA Astrophysics Data System (ADS)

    Hiltunen, Teppo; Laakso, Jouni; Kaitala, Veijo; Suomalainen, Lotta-Riina; Pekkonen, Minna

    2008-05-01

    Competition theory generally predicts that diversity is maintained by temporal environmental fluctuations. One of the many suggested mechanisms for maintaining diversity in fluctuating environments is the gleaner-opportunist trade-off, whereby gleaner species have low threshold resource levels and low maximum growth rates in high resource concentration while opportunist species show opposite characteristics. We measured the growth rates of eight heterotrophic aquatic bacteria under different concentrations of chemically complex plant detritus resource. The growth rates revealed gleaner-opportunist trade-offs. The role of environmental variability in maintaining diversity was tested in a 28-day experiment with three different resource fluctuation regimes imposed on two four-species bacterial communities in microcosms. We recorded population densities with serial dilution plating and total biomass as turbidity. Changes in resource availability were measured from filter-sterilised medium by re-introducing the consumer species and recording short-term growth rates. The type of environmental variation had no effect on resource availability, which declined slowly during the experiment and differed in level between the communities. However, the slowly fluctuating environment had the highest Shannon diversity index, biomass, and coefficient of variation of biomass in both communities. We did not find a clear link between the gleaner-opportunist trade-off and diversity in fluctuating environments. Nevertheless, our results do not exclude this explanation and support the general view that temporal environmental variation maintains species diversity also in communities feeding chemically complex resource.

  13. Carbohydrate Mouth Rinse Maintains Muscle Electromyographic Activity and Increases Time to Exhaustion during Moderate but not High-Intensity Cycling Exercise

    PubMed Central

    Bastos-Silva, Victor José; Melo, Alan de Albuquerque; Lima-Silva, Adriano Eduardo; Moura, Felipe Arruda; Bertuzzi, Rômulo; de Araujo, Gustavo Gomes

    2016-01-01

    The aim was to investigate the influence of a carbohydrate (CHO) mouth rinse on the vastus lateralis (VL) and rectus femoris (RF) electromyographic activity (EMG) and time to exhaustion (TE) during moderate (MIE) and high-intensity cycling exercise (HIE). Thirteen participants cycled at 80% of their respiratory compensation point and at 110% of their peak power output to the point of exhaustion. Before the trials and every 15 min during MIE, participants rinsed with the CHO or Placebo (PLA) solutions. The root mean square was calculated. CHO had no effect on the TE during HIE (CHO: 177.3 ± 42.2 s; PLA: 163.0 ± 26.7 s, p = 0.10), but the TE was increased during MIE (CHO: 76.6 ± 19.7 min; PLA: 65.4 ± 15.2 min; p = 0.01). The EMG activity in the VL was higher than PLA at 30 min (CHO: 10.5% ± 2.6%; PLA: 7.7% ± 3.3%; p = 0.01) and before exhaustion (CHO: 10.3% ± 2.5%; PLA: 8.0% ± 2.9%; p = 0.01) with CHO rinsing. There was no CHO effect on the EMG activity of RF during MIE or for VL and RF during HIE. CHO mouth rinse maintains EMG activity and enhances performance for MIE but not for HIE. PMID:27005660

  14. Molecular simplification of 1,4-diazabicyclo[4.3.0]nonan-9-ones gives piperazine derivatives that maintain high nootropic activity.

    PubMed

    Manetti, D; Ghelardini, C; Bartolini, A; Dei, S; Galeotti, N; Gualtieri, F; Romanelli, M N; Teodori, E

    2000-11-16

    Several 4-substituted 1-acylpiperazines, obtained by molecular simplification of 4-substituted 1,4-diazabicyclo[4.3.0]nonan-9-ones, have been synthesized and tested in vivo on the mouse passive avoidance test, to evaluate their nootropic activity. The results show that, apparently, an N-acylpiperazine group can mimic the 2-pyrrolidinone ring of 1,4-diazabicyclo[4.3.0]nonan-9-one, as the compounds of the new series maintain high nootropic activity. Moreover molecular simplification produces more clear-cut structure-activity relationships with respect to the parent series. The mechanism of action also appears to be similar in the two series. In fact, although the molecular mechanism remains to be elucidated, the most potent compound of each class (DM232 and 13, DM235) is able to increase acetylcholine release in rat brain. Piperazine derivatives represent a new class of nootropic drugs with an in vivo pharmacological profile very similar to that of piracetam, showing much higher potency with respect to the reference compound. Among the compounds studied, 13 (DM235) shows outstanding potency, being active at a dose of 0.001 mg kg(-1) sc.

  15. Activation of high and low affinity dopamine receptors generates a closed loop that maintains a conductance ratio and its activity correlate

    PubMed Central

    Krenz, Wulf-Dieter C.; Hooper, Ryan M.; Parker, Anna R.; Prinz, Astrid A.; Baro, Deborah J.

    2013-01-01

    Neuromodulators alter network output and have the potential to destabilize a circuit. The mechanisms maintaining stability in the face of neuromodulation are not well described. Using the pyloric network in the crustacean stomatogastric nervous system, we show that dopamine (DA) does not simply alter circuit output, but activates a closed loop in which DA-induced alterations in circuit output consequently drive a change in an ionic conductance to preserve a conductance ratio and its activity correlate. DA acted at low affinity type 1 receptors (D1Rs) to induce an immediate modulatory decrease in the transient potassium current (IA) of a pyloric neuron. This, in turn, advanced the activity phase of that component neuron, which disrupted its network function and thereby destabilized the circuit. DA simultaneously acted at high affinity D1Rs on the same neuron to confer activity-dependence upon the hyperpolarization activated current (Ih) such that the DA-induced changes in activity subsequently reduced Ih. This DA-enabled, activity-dependent, intrinsic plasticity exactly compensated for the modulatory decrease in IA to restore the IA:Ih ratio and neuronal activity phase, thereby closing an open loop created by the modulator. Activation of closed loops to preserve conductance ratios may represent a fundamental operating principle neuromodulatory systems use to ensure stability in their target networks. PMID:24155696

  16. Analysis of high-speed growth of silicon sheet in inclined-meniscus configuration

    NASA Technical Reports Server (NTRS)

    Thomas, P. D.; Brown, R. A.

    1985-01-01

    The study of high speed growth of silicon sheet in inclined-meniscus configurations is discussed. It was concluded that the maximum growth rates in vertical and inclined growth are set by thermal-capillary limits. Also, the melt/crystal interface was determined to be flat. And, vertical growth is qualitatively modelled by one dimensional heat transfer.

  17. Reduced instability growth with high-adiabat high-foot implosions at the National Ignition Facility.

    PubMed

    Casey, D T; Smalyuk, V A; Raman, K S; Peterson, J L; Berzak Hopkins, L; Callahan, D A; Clark, D S; Dewald, E L; Dittrich, T R; Haan, S W; Hinkel, D E; Hoover, D; Hurricane, O A; Kroll, J J; Landen, O L; Moore, A S; Nikroo, A; Park, H-S; Remington, B A; Robey, H F; Rygg, J R; Salmonson, J D; Tommasini, R; Widmann, K

    2014-07-01

    Hydrodynamic instabilities are a major obstacle in the quest to achieve ignition as they cause preexisting capsule defects to grow and ultimately quench the fusion burn in experiments at the National Ignition Facility. Unstable growth at the ablation front has been dramatically reduced in implosions with "high-foot" drives as measured using x-ray radiography of modulations at the most dangerous wavelengths (Legendre mode numbers of 30-90). These growth reductions have helped to improve the performance of layered DT implosions reported by O. A. Hurricane et al. [Nature (London) 506, 343 (2014)], when compared to previous "low-foot" experiments, demonstrating the value of stabilizing ablation-front growth and providing directions for future ignition designs.

  18. Microorganisms under high pressure--adaptation, growth and biotechnological potential.

    PubMed

    Mota, Maria J; Lopes, Rita P; Delgadillo, Ivonne; Saraiva, Jorge A

    2013-12-01

    Hydrostatic pressure is a well-known physical parameter which is now considered an important variable of life, since organisms have the ability to adapt to pressure changes, by the development of resistance against this variable. In the past decades a huge interest in high hydrostatic pressure (HHP) technology is increasingly emerging among food and biosciences researchers. Microbial specific stress responses to HHP are currently being investigated, through the evaluation of pressure effects on biomolecules, cell structure, metabolic behavior, growth and viability. The knowledge development in this field allows a better comprehension of pressure resistance mechanisms acquired at sub-lethal pressures. In addition, new applications of HHP could arise from these studies, particularly in what concerns to biotechnology. For instance, the modulation of microbial metabolic pathways, as a response to different pressure conditions, may lead to the production of novel compounds with potential biotechnological and industrial applications. Considering pressure as an extreme life condition, this review intends to present the main findings so far reported in the scientific literature, focusing on microorganisms with the ability to withstand and to grow in high pressure conditions, whether they have innated or acquired resistance, and show the potential of the application of HHP technology for microbial biotechnology. © 2013.

  19. Policy makers will need a way to update bundled payments that reflects highly skewed spending growth of various care episodes.

    PubMed

    Rosen, Allison B; Aizcorbe, Ana; Ryu, Alexander J; Nestoriak, Nicole; Cutler, David M; Chernew, Michael E

    2013-05-01

    Bundled payment entails paying a single price for all services delivered as part of an episode of care for a specific condition. It is seen as a promising way to slow the growth of health care spending while maintaining or improving the quality of care. To implement bundled payment, policy makers must set base payment rates for episodes of care and update the rates over time to reflect changes in the costs of delivering care and the components of care. Adopting the fee-for-service paradigm of adjusting payments with uniform update rates would be fair and accurate if costs increased at a uniform rate across episodes. But our analysis of 2003 and 2007 US commercial claims data showed spending growth to be highly skewed across episodes: 10 percent of episodes accounted for 82.5 percent of spending growth, and within-episode spending growth ranged from a decline of 75 percent to an increase of 323 percent. Given that spending growth was much faster for some episodes than for others, a situation known as skewness, policy makers should not update episode payments using uniform update rates. Rather, they should explore ways to address variations in spending growth, such as updating episode payments one by one, at least at the outset.

  20. Proline 107 Is a Major Determinant in Maintaining the Structure of the Distal Pocket and Reactivity of the High-Spin Heme of MauG

    SciTech Connect

    Feng, Manliang; Jensen, Lyndal M.R.; Yukl, Erik T.; Wei, Xiaoxi; Liu, Aimin; Wilmot, Carrie M.; Davidson, Victor L.

    2012-05-09

    The diheme enzyme MauG catalyzes a six-electron oxidation required for posttranslational modification of a precursor of methylamine dehydrogenase (preMADH) to complete the biosynthesis of its protein-derived tryptophan tryptophylquinone (TTQ) cofactor. Crystallographic studies had shown that Pro107, which resides in the distal pocket of the high-spin heme of MauG, changes conformation upon binding of CO or NO to the heme iron. In this study, Pro107 was converted to Cys, Val, and Ser by site-directed mutagenesis. The structures of each of these MauG mutant proteins in complex with preMADH were determined, as were their physical and catalytic properties. P107C MauG was inactive, and the crystal structure revealed that Cys107 had been oxidatively modified to a sulfinic acid. Mass spectrometry revealed that this modification was present prior to crystallization. P107V MauG exhibited spectroscopic and catalytic properties that were similar to those of wild-type MauG, but P107V MauG was more susceptible to oxidative damage. The P107S mutation caused a structural change that resulted in the five-coordinate high-spin heme being converted to a six-coordinate heme with a distal axial ligand provided by Glu113. EPR and resonance Raman spectroscopy revealed this heme remained high-spin but with greatly increased rhombicity as compared to that of the axial signal of wild-type MauG. P107S MauG was resistant to reduction by dithionite and reaction with H{sub 2}O{sub 2} and unable to catalyze TTQ biosynthesis. These results show that the presence of Pro107 is critical in maintaining the proper structure of the distal heme pocket of the high-spin heme of MauG, allowing exogenous ligands to bind and directing the reactivity of the heme-activated oxygen during catalysis, thus minimizing the oxidation of other residues of MauG.

  1. Plasticity in sunflower leaf and cell growth under high salinity.

    PubMed

    Céccoli, G; Bustos, D; Ortega, L I; Senn, M E; Vegetti, A; Taleisnik, E

    2015-01-01

    A group of sunflower lines that exhibit a range of leaf Na(+) concentrations under high salinity was used to explore whether the responses to the osmotic and ionic components of salinity can be distinguished in leaf expansion kinetics analysis. It was expected that at the initial stages of the salt treatment, leaf expansion kinetics changes would be dominated by responses to the osmotic component of salinity, and that later on, ion inclusion would impose further kinetics changes. It was also expected that differential leaf Na(+) accumulation would be reflected in specific changes in cell division and expansion rates. Plants of four sunflower lines were gradually treated with a relatively high (130 mm NaCl) salt treatment. Leaf expansion kinetics curves were compared in leaves that were formed before, during and after the initiation of the salt treatment. Leaf areas were smaller in salt-treated plants, but the analysis of growth curves did not reveal differences that could be attributed to differential Na(+) accumulation, since similar changes in leaf expansion kinetics were observed in lines with different magnitudes of salt accumulation. Nevertheless, in a high leaf Na(+) -including line, cell divisions were affected earlier, resulting in leaves with proportionally fewer cells than in a Na(+) -excluding line. A distinct change in leaf epidermal pavement shape caused by salinity is reported for the first time. Mature pavement cells in leaves of control plants exhibited typical lobed, jigsaw-puzzle shape, whereas in treated plants, they tended to retain closer-to-circular shapes and a lower number of lobes. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

  2. Shigella reroutes host cell central metabolism to obtain high-flux nutrient supply for vigorous intracellular growth.

    PubMed

    Kentner, David; Martano, Giuseppe; Callon, Morgane; Chiquet, Petra; Brodmann, Maj; Burton, Olga; Wahlander, Asa; Nanni, Paolo; Delmotte, Nathanaël; Grossmann, Jonas; Limenitakis, Julien; Schlapbach, Ralph; Kiefer, Patrick; Vorholt, Julia A; Hiller, Sebastian; Bumann, Dirk

    2014-07-08

    Shigella flexneri proliferate in infected human epithelial cells at exceptionally high rates. This vigorous growth has important consequences for rapid progression to life-threatening bloody diarrhea, but the underlying metabolic mechanisms remain poorly understood. Here, we used metabolomics, proteomics, and genetic experiments to determine host and Shigella metabolism during infection in a cell culture model. The data suggest that infected host cells maintain largely normal fluxes through glycolytic pathways, but the entire output of these pathways is captured by Shigella, most likely in the form of pyruvate. This striking strategy provides Shigella with an abundant favorable energy source, while preserving host cell ATP generation, energy charge maintenance, and survival, despite ongoing vigorous exploitation. Shigella uses a simple three-step pathway to metabolize pyruvate at high rates with acetate as an excreted waste product. The crucial role of this pathway for Shigella intracellular growth suggests targets for antimicrobial chemotherapy of this devastating disease.

  3. Shigella reroutes host cell central metabolism to obtain high-flux nutrient supply for vigorous intracellular growth

    PubMed Central

    Kentner, David; Martano, Giuseppe; Callon, Morgane; Chiquet, Petra; Brodmann, Maj; Burton, Olga; Wahlander, Asa; Nanni, Paolo; Delmotte, Nathanaël; Grossmann, Jonas; Limenitakis, Julien; Schlapbach, Ralph; Kiefer, Patrick; Vorholt, Julia A.; Hiller, Sebastian; Bumann, Dirk

    2014-01-01

    Shigella flexneri proliferate in infected human epithelial cells at exceptionally high rates. This vigorous growth has important consequences for rapid progression to life-threatening bloody diarrhea, but the underlying metabolic mechanisms remain poorly understood. Here, we used metabolomics, proteomics, and genetic experiments to determine host and Shigella metabolism during infection in a cell culture model. The data suggest that infected host cells maintain largely normal fluxes through glycolytic pathways, but the entire output of these pathways is captured by Shigella, most likely in the form of pyruvate. This striking strategy provides Shigella with an abundant favorable energy source, while preserving host cell ATP generation, energy charge maintenance, and survival, despite ongoing vigorous exploitation. Shigella uses a simple three-step pathway to metabolize pyruvate at high rates with acetate as an excreted waste product. The crucial role of this pathway for Shigella intracellular growth suggests targets for antimicrobial chemotherapy of this devastating disease. PMID:24958876

  4. Growth

    NASA Astrophysics Data System (ADS)

    Waag, Andreas

    This chapter is devoted to the growth of ZnO. It starts with various techniques to grow bulk samples and presents in some detail the growth of epitaxial layers by metal organic chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE), and pulsed laser deposition (PLD). The last section is devoted to the growth of nanorods. Some properties of the resulting samples are also presented. If a comparison between GaN and ZnO is made, very often the huge variety of different growth techniques available to fabricate ZnO is said to be an advantage of this material system. Indeed, growth techniques range from low cost wet chemical growth at almost room temperature to high quality MOCVD growth at temperatures above 1, 000∘C. In most cases, there is a very strong tendency of c-axis oriented growth, with a much higher growth rate in c-direction as compared to other crystal directions. This often leads to columnar structures, even at relatively low temperatures. However, it is, in general, not straight forward to fabricate smooth ZnO thin films with flat surfaces. Another advantage of a potential ZnO technology is said to be the possibility to grow thin films homoepitaxially on ZnO substrates. ZnO substrates are mostly fabricated by vapor phase transport (VPT) or hydrothermal growth. These techniques are enabling high volume manufacturing at reasonable cost, at least in principle. The availability of homoepitaxial substrates should be beneficial to the development of ZnO technology and devices and is in contrast to the situation of GaN. However, even though a number of companies are developing ZnO substrates, only recently good quality substrates have been demonstrated. However, these substrates are not yet widely available. Still, the situation concerning ZnO substrates seems to be far from low-cost, high-volume production. The fabrication of dense, single crystal thin films is, in general, surprisingly difficult, even when ZnO is grown on a ZnO substrate. However

  5. Effect of a High-Rate Versus a Low-Rate Oxytocin Infusion for Maintaining Uterine Contractility During Elective Cesarean Delivery: A Prospective Randomized Clinical Trial.

    PubMed

    Duffield, Adrienne; McKenzie, Christine; Carvalho, Brendan; Ramachandran, Bharathi; Yin, Victoria; El-Sayed, Yasser Y; Riley, Edward T; Butwick, Alexander J

    2017-03-01

    Oxytocin is routinely used as prophylaxis against uterine atony. During elective cesarean delivery (CD), an oxytocin bolus is used to initiate adequate uterine tone, followed by an oxytocin infusion to maintain uterine contractility. However, it is unclear whether oxytocin maintenance infusion rate influences total estimated blood loss (EBL). We performed a prospective, randomized, double-blind trial in 51 women undergoing elective CD. Women were randomly assigned to receive an oxytocin maintenance infusion of 2.5 or 15 U/h. All women received an oxytocin 1 U bolus to initiate adequate uterine tone. The primary outcome was EBL. EBL values between groups were compared using a Mann-Whitney U test; P < .05 as statistically significant. The median EBL difference with 95% confidence intervals was also calculated. Secondary outcomes included adequacy of uterine tone, use of additional uterotonics, and oxytocin-related side effects, including hypotension. Of 51 women, 24 received a low-rate infusion and 27 received a high-rate infusion. Median (interquartile range) EBL values in the low-rate and high-rate groups were 634 (340-886) mL versus 512 (405-740) mL, respectively (P = .7). The median difference in EBL between groups was 22 mL; 95% confidence interval = -158 to 236 mL. The rate of postpartum hemorrhage did not differ between groups (low-rate group: 4/24 [16.7%] versus high-rate group: 4/26 [15.4%]). There were no between-group differences over time (first 20 minutes after commencing infusion) in the incidence of adequate uterine tone (P = .72) or hypotension (P = .32). Among women undergoing elective CD receiving an oxytocin maintenance infusion, EBL and uterine tone did not differ between women receiving 2.5 U/h oxytocin and those receiving 15 U/h oxytocin. Our findings suggest that efficacy can be obtained with a low oxytocin maintenance infusion rate; however, dose-finding studies are needed to determine the infusion rate that optimizes drug efficacy while

  6. High-density polyethylene (HDPE) faces slower growth

    SciTech Connect

    Savage, R.

    1980-05-19

    According to R. Savage of American Hoechst Corp., the 1979 U.S. HDPE capacity, production, plant operating rate, domestic shipments, and total shipments are (in millions of lb) 5400, 5010, 93%, 4284, and 4893, respectively. For 1984, the corresponding figures are 8800, 7300, 83%, 6500, and 7150. HDPE is entering the 'mature' phase of its cycle, and will not, in the future, be able to match the 13.3%/yr avg growth rate for the last five years, but the increase in capacity this year to 6 billion lb and the predicted 7.9%/yr avg increase through 1984, indicate that HDPE will outperform much of its competition. Plant operating rates were high last year because some HDPE capacity was converted to low-density polyethylene capacity. The HDPE export market will remain flat through 1984 because other countries are increasing capacity and the U.S. price advantage will disappear. HDPE capacity additions planned by U.S. companies, and HDPE uses, particularly blow-molding and injecting molding applications (the major uses of HDPE), are discussed.

  7. Neural plasticity maintained high by activation of cyclic AMP-dependent protein kinase: an age-independent, general mechanism in cat striate cortex.

    PubMed

    Imamura, K; Kasamatsu, T; Tanaka, S

    2007-06-29

    general mechanism to maintain ocular dominance plasticity high, their sensitivity being substantially higher in the immature than mature cortex.

  8. The growth of massive galaxies and clusters at high redshift

    NASA Astrophysics Data System (ADS)

    Lindner, Robert Raymond

    2013-12-01

    Massive galaxies and galaxy clusters gain much of their mass by merging with their neighbors; this hierarchical structure formation is the foundation of our understanding of galaxy evolution. Nevertheless, the detailed evolutionary processes needed to form the structures we see in the local Universe remain poorly understood. This thesis comprises four projects examining the growth of galaxies and clusters at high redshift by using radio, sub/millimeter, and X-ray observations to provide empirical constraints on their cosmic evolution. Chapter 2 presents deep 1.2mm imaging of the inner 20' x 20' of the Lockman Hole North (LHN) field to search for submillimeter galaxies (SMGs), rapidly star-forming, high-redshift galaxy mergers. We detect 41 SMGs with S/N>4.0 and use Monte Carlo simulations to estimate their number counts and angular clustering properties. Chapter 3 investigates the nuclear accretion properties of the LHN SMGs. In the sample's average rest-frame X-ray spectrum, we detect strong Fe K alpha emission (equivalent width EW >=1 keV) from highly-ionized Fe species -- evidence that beneath the galaxies' heavy obscuration, supermassive black holes may be growing rapidly. Chapter 4 describes a new 345 GHz and 2.1 GHz imaging campaign to study the intracluster media (ICM) of eleven massive Sunyaev Zel'dovich Effect (SZE)-detected clusters from the Atacama Cosmology Telescope (ACT) southern survey. In six of eleven, 345 GHz SZE increments are detected and used to characterize the spatial distribution and energy content of the ICM at high (19.2") resolution. This work helps us understand how SZE-mass scaling relations are affected by contamination from other sources along the line of sight and by dynamical properties of the ICM. Chapter 5 studies the non-thermal radio emission in one exceptional z=0.870 binary cluster merger (ACTJ0102-4915, ``El Gordo'') with the help of newly-acquired radio observations. El Gordo is the highest-redshift cluster known to host

  9. High growth rate homoepitaxial diamond film deposition at high temperatures by microwave plasma-assisted chemical vapor deposition

    NASA Technical Reports Server (NTRS)

    Vohra, Yogesh K. (Inventor); McCauley, Thomas S. (Inventor)

    1997-01-01

    The deposition of high quality diamond films at high linear growth rates and substrate temperatures for microwave-plasma chemical vapor deposition is disclosed. The linear growth rate achieved for this process is generally greater than 50 .mu.m/hr for high quality films, as compared to rates of less than 5 .mu.m/hr generally reported for MPCVD processes.

  10. Maintaining DACUM Quality.

    ERIC Educational Resources Information Center

    Norton, Robert E.

    This document discusses the importance of maintaining the quality of DACUM (Developing a Curriculum) occupational analyses and presents a 2-page checklist detailing DACUM quality performance criteria. The introduction to the checklist discusses various "infractions" discovered during an analyses of some curriculum/program developers'…

  11. Diversity & Community: Maintaining Allegiances.

    ERIC Educational Resources Information Center

    Pena, Devon G.

    1990-01-01

    The quest for diversity must overcome the resistance of traditional White, male faculty to redefining the mission and curriculum of the liberal arts college. Change will be difficult, but it must occur if liberal arts colleges are to survive and maintain a central and relevant place in multicultural America. (MSE)

  12. Maintaining Medicinal Plant Germplasm

    USDA-ARS?s Scientific Manuscript database

    For all plant genetic resources collections, including medicinal plant germplasm, maintaining the genetic integrity of material held ex situ is of major importance. This holds true for all intended end uses of the material whether it is as a source for crop improvement, medical research, as voucher...

  13. High level runners are able to maintain a VO2 steady-state below VO2max in an all-out run over their critical velocity.

    PubMed

    Billat, V; Binsse, V; Petit, B; Koralsztein, J P

    1998-02-01

    During prolonged and intense running exercises beyond the critical power level, a VO2 slow component elevates VO2 above predicted VO2-work rates calculated from exercise performed at intensities below the lactate threshold. In such cases, the actual VO2 value will increase over time until it reaches VO2max. The aims of the present study were to examine whether the VO2 slow component is a major determinant of VO2 over time when running at a speed beyond critical velocity, and whether the exhaustion latency period at such intensity correlates with the magnitude of the VO2 slow component. Fourteen highly trained long-distance runners performed four exhaustive runs, each separated by one week of light training. VO2 and the velocity at VO2max (vVO2max) were determined for each by a graded treadmill exercise. The critical velocity (86.1 +/- 1.5% vVO2max) of each runner was calculated from exhaustive treadmill runs at 90, 100 and 105% of vVO2max. During supra-critical velocity runs at 90% of vVO2max, there was no significant rise in VO2max (20.9 +/- 2.1 ml min-1 kg-1 between the third and last min of tlim 90), such that the runners reached a VO2 steady-state, but did not reach their vVO2max level over time (69.5 +/- 5.0 vs 74.9 +/- 3.0 ml min-1 kg-1). Thus, subjects' time to exhaustion at 90% of vVO2max was not correlated with the VO2max slow component (r = 0.11, P = 0.69), but significantly correlated with the lactate threshold (r = 0.54, P = 0.04) and the critical velocity (% vVO2max; r = 0.65, P = 0.01). In conclusion, the present study demonstrates that for highly trained long-distance runners performing exhaustive, supra-critical velocity runs at 90% of vVO2max, there was not a VO2 slow component tardily completing the rise of VO2. Instead, runners will maintain a VO2 steady-state below VO2max, such that the time to exhaustion at 90% of vVO2max for these runners is positively correlated with the critical velocity expressed as % of vVO2max.

  14. Growth of diamond microcrystals by the oriented attachment mechanism at high pressure and high temperature

    NASA Astrophysics Data System (ADS)

    Kidalov, S. V.; Shakhov, F. M.; Shvidchenko, A. V.; Smirnov, A. N.; Sokolov, V. V.; Yagovkina, M. A.; Vul', A. Ya.

    2017-01-01

    For the first time it has been experimentally shown that a powder of detonation nanodiamonds (DND) and a saturated acyclic hydrocarbon, mono- or dibasic alcohol, used as the reaction mixture after treatment at high pressures (5-8 GPa) and high temperatures (1300-1800°C) results in the formation of diamond single crystals up to 15 micron in size. The Raman spectrum indicates that the diamonds have a perfect of crystal structure. It has been suggested that the oriented attachment mechanism is responsible for growth of micrometer-size diamond single crystals out of DND particles with sizes of about 5 nm under these technological conditions.

  15. Maintaining High Quality Network Performance at the GSN: Sensor Installation Methods, New VBB Borehole Sensors and Data Quality Assessment from MUSTANG

    NASA Astrophysics Data System (ADS)

    Hafner, Katrin

    2017-04-01

    Data Management Center, which not only maintains the data archive, but also provides easy, rapid, and open access to data recorded from seconds to decades ago. All data flow to the IRIS DMC through the UCSD or ASL Data Collection Centers (DCCs). The DCCs focus on delivering data to the DMC, maintaining correct metadata for GSN stations, reviewing data quality from the stations that ASL and UCSD operate, and addressing circumstances that require special data handling, such as back filling following telemetry outages. Key to the high quality of the GSN data is the direct feedback on data quality problems identified by the DCC analysts to the network operations staff and field engineers. Aging of GSN equipment and station infrastructure has resulted in renewed emphasis on using data quality control tools such as MUSTANG. These tools allow the network operators to routinely monitor and analyze waveform data to detect and track problems and develop short and longer term action plans for improving network data quality. We will present summary data quality metrics for the GSN as obtained via these quality assurance tools.

  16. Growth

    Treesearch

    John R. Jones; George A. Schier

    1985-01-01

    This chapter considers aspen growth as a process, and discusses some characteristics of the growth and development of trees and stands. For the most part, factors affecting growth are discussed elsewhere, particularly in the GENETICS AND VARIATION chapter and in chapters in PART 11. ECOLOGY. Aspen growth as it relates to wood production is examined in the WOOD RESOURCE...

  17. High growth rate 4H-SiC epitaxial growth using dichlorosilane in a hot-wall CVD reactor

    NASA Astrophysics Data System (ADS)

    Chowdhury, Iftekhar; Chandrasekhar, M. V. S.; Klein, Paul B.; Caldwell, Joshua D.; Sudarshan, Tangali

    2011-02-01

    Thick, high quality 4H-SiC epilayers have been grown in a vertical hot-wall chemical vapor deposition system at a high growth rate on (0 0 0 1) 8° off-axis substrates. We discuss the use of dichlorosilane as the Si-precursor for 4H-SiC epitaxial growth as it provides the most direct decomposition route into SiCl 2, which is the predominant growth species in chlorinated chemistries. A specular surface morphology was attained by limiting the hydrogen etch rate until the system was equilibrated at the desired growth temperature. The RMS roughness of the grown films ranged from 0.5-2.0 nm with very few morphological defects (carrots, triangular defects, etc.) being introduced, while enabling growth rates of 30-100 μm/h, 5-15 times higher than most conventional growths. Site-competition epitaxy was observed over a wide range of C/Si ratios, with doping concentrations <1×10 14 cm -3 being recorded. X-ray rocking curves indicated that the epilayers were of high crystallinity, with linewidths as narrow as 7.8 arcsec being observed, while microwave photoconductive decay (μPCD) measurements indicated that these films had high injection (ambipolar) carrier lifetimes in the range of 2 μs.

  18. Nuclear power plant maintainability.

    PubMed

    Seminara, J L; Parsons, S O

    1982-09-01

    In the mid-1970s a general awareness of human factors engineering deficiencies associated with power plant control rooms took shape and the Electric Power Research Institute (EPRI) awarded the Lockheed Corporation a contract to review the human factors aspects of five representative operational control rooms and their associated simulators. This investigation revealed a host of major and minor deficiencies that assumed unforeseen dimensions in the post- Three Mile Island accident period. In the course of examining operational problems (Seminara et al, 1976) and subsequently the methods for overcoming such problems (Seminara et al, 1979, 1980) indications surfaced that power plants were far from ideal in meeting the needs of maintenance personnel. Accordingly, EPRI sponsored an investigation of the human factors aspects of power plant maintainability (Seminara, 1981). This paper provides an overview of the maintainability problems and issues encountered in the course of reviewing five nuclear power plants.

  19. Life history and past demography maintain genetic structure, outcrossing rate, contemporary pollen gene flow of an understory herb in a highly fragmented rainforest

    PubMed Central

    Suárez-Montes, Pilar; Chávez-Pesqueira, Mariana

    2016-01-01

    . Aphelandra aurantiaca shows a mixed mating system (tm = 0.81) and the outcrossing rate have not been affected by habitat fragmentation. A strong pollen pool structure was detected due to few effective pollen donors (Nep) and low distance pollen movement, pointing that most plants received pollen from close neighbors. Past demographic fluctuations may have affected the present population genetic structure as Bayesian coalescent analysis revealed the signature of past population expansion, possibly during warmer conditions after the last glacial maximum. Discussion Habitat fragmentation has not increased genetic differentiation or reduced genetic diversity of A. aurantiaca despite dozens of generations since the onset of fragmentation in the region of Los Tuxtlas. Instead, past population expansion is compatible with the lack of observed genetic structure. The predicted negative effects of rainforest fragmentation on genetic diversity and population structure of A. aurantiaca seem to have been buffered owing to its large effective populations and long-distance dispersal events. In particular, its mixed-mating system, mostly of outcrossing, suggests high efficiency of pollinators promoting connectivity and reducing inbreeding. However, some results point that the effects of fragmentation are underway, as two small fragments showed higher membership probabilities to their population of origin, suggesting genetic isolation. Our findings underscore the importance of fragment size to maintain genetic connectivity across the landscape. PMID:28028460

  20. Life history and past demography maintain genetic structure, outcrossing rate, contemporary pollen gene flow of an understory herb in a highly fragmented rainforest.

    PubMed

    Suárez-Montes, Pilar; Chávez-Pesqueira, Mariana; Núñez-Farfán, Juan

    2016-01-01

    a mixed mating system (tm  = 0.81) and the outcrossing rate have not been affected by habitat fragmentation. A strong pollen pool structure was detected due to few effective pollen donors (Nep ) and low distance pollen movement, pointing that most plants received pollen from close neighbors. Past demographic fluctuations may have affected the present population genetic structure as Bayesian coalescent analysis revealed the signature of past population expansion, possibly during warmer conditions after the last glacial maximum. Habitat fragmentation has not increased genetic differentiation or reduced genetic diversity of A. aurantiaca despite dozens of generations since the onset of fragmentation in the region of Los Tuxtlas. Instead, past population expansion is compatible with the lack of observed genetic structure. The predicted negative effects of rainforest fragmentation on genetic diversity and population structure of A. aurantiaca seem to have been buffered owing to its large effective populations and long-distance dispersal events. In particular, its mixed-mating system, mostly of outcrossing, suggests high efficiency of pollinators promoting connectivity and reducing inbreeding. However, some results point that the effects of fragmentation are underway, as two small fragments showed higher membership probabilities to their population of origin, suggesting genetic isolation. Our findings underscore the importance of fragment size to maintain genetic connectivity across the landscape.

  1. Highly efficient growth of vertically aligned carbon nanotubes on Fe-Ni based metal alloy foils for supercapacitors

    NASA Astrophysics Data System (ADS)

    Amalina Raja Seman, Raja Noor; Asyadi Azam, Mohd; Ambri Mohamed, Mohd

    2016-12-01

    Supercapacitors are highly promising energy devices with superior charge storage performance and a long lifecycle. Construction of the supercapacitor cell, especially electrode fabrication, is critical to ensure good performance in applications. This work demonstrates direct growth of vertically aligned carbon nanotubes (CNTs) on Fe-Ni based metal alloy foils, namely SUS 310S, Inconel 600 and YEF 50, and their use in symmetric vertically aligned CNT supercapacitor electrodes. Alumina and cobalt thin film catalysts were deposited onto the foils, and then CNT growth was performed using alcohol catalytic chemical vapour deposition. By this method, vertically aligned CNTs were successfully grown and used directly as a binder-free supercapacitor electrode to deliver excellent electrochemical performance. The device showed relatively good specific capacitance, a superior rate capability and excellent cycle stability, maintaining about 96% capacitance up to 1000 cycles.

  2. Influence of high pressure hydrogen on cyclic load crack growth in metals

    NASA Technical Reports Server (NTRS)

    Jewett, R. P.; Walter, R. J.; Chandler, W. T.

    1978-01-01

    The effect of high pressure hydrogen on the crack growth rate of various nickel-base alloys was studied at ambient temperature. Considerable enhancement of the cyclic flaw growth rate was observed for Inconel 718, wrought and cast, and Waspaloy, a nickel-base alloy similar to Inconel 718. Only slight enhancement of the flaw growth rate for Alloy 903 was observed.

  3. High mortality and poor growth of green mussels, Perna viridis, in high chlorophyll- a environment

    NASA Astrophysics Data System (ADS)

    Soon, Tan Kar; Denil, Delta Jenetty; Ransangan, Julian

    2016-03-01

    The current study was carried out from May 2014 to April 2015 to estimate the stock status of P. viridis in Marudu Bay. The gonad development was monitored by histological examination, while the population parameters including asymptotic length ( L ∞), growth coefficient ( K), mortality rate ( Z, F and M), exploitation level ( E) and recruitment of P. viridis were estimated using the lengthfrequency data. Results of the current study demonstrated that P. viridis in Marudu Bay spawned throughout the year with two major peaks, one in April to May and another one in October to December. The recruitment pattern was continuous with the peak in May to June 2014, which corresponded to the first spawning peak in April. However, no significant recruitment was observed from the second spawning peak due to the difference in spawning timing between male and female populations. The estimated asymptotic length ( L ∞), growth coefficient ( K), total mortality ( Z), natural mortality ( M), fishing mortality ( F) and growth performance ( φ) of P. viridis in Marudu Bay were estimate to be 117 mm, 0.97 yr-1, 4.39 yr-1, 1.23 yr-1, 3.16 yr-1 and 4.123, respectively. The exponent b of the lengthweight relationship was 2.4 and exploitation level ( E) was 0.72. The high mortality, low condition indices and negative allometric of P. viridis in Marudu Bay is caused by a lack of suitable food in the surrounding water.

  4. The Survey and Analysis of Excellent Senior High School Physics Teachers' Professional Growth Actuality

    ERIC Educational Resources Information Center

    Sun, Haibin; Liu, Tingting

    2010-01-01

    Excellent senior high school physics teachers are the backbone power in the new course reform of physics in China. The excellent senior high school physics teachers' professional growth actuality in Shandong is surveyed in this article by the self-made "Questionnaire of Excellent Senior High School Physics Teachers' Professional Growth",…

  5. A High Through-put Combinatorial Growth Technique for Semiconductor Thin Film Search

    NASA Astrophysics Data System (ADS)

    Ma, Z. X.; Hao, H. Y.; Xiao, P.; Oehlerking, L. J.; Liu, D. F.; Zhang, X. J.; Yu, K.-M.; Walukiewicz, W.; Mao, S. S.; Yu, P. Y.

    2011-12-01

    Conventional semiconductor material growth technique is costly and time-consuming. Here we developed a new method to growth semiconductor thin films using high through-put combinatorial technique. In this way, we have successfully fabricated tens of semiconductor libraries with high crystallinity and high product of μτ for the purpose of radiation detection.

  6. The mechanism of eutectic growth in highly anisotropic materials

    PubMed Central

    Shahani, Ashwin J.; Xiao, Xianghui; Voorhees, Peter W.

    2016-01-01

    In the past 50 years, there has been increasing interest—both theoretically and experimentally—in the problem of pattern formation of a moving boundary, such as a solidification front. One example of pattern formation is that of irregular eutectic solidification, in which the solid–liquid interface is non-isothermal and the interphase spacing varies in ways that are poorly understood. Here, we identify the growth mode of irregular eutectics, using reconstructions from four-dimensional (that is, time and space resolved) X-ray microtomography. Our results show that the eutectic growth process can be markedly different from that seen in previously used model systems and theories based on the ex situ analysis of microstructure. In light of our experimental findings, we present a coherent growth model of irregular eutectic solidification. PMID:27671764

  7. Very-high-growth-factor Planar Ablative Rayleigh Taylor Experiments

    SciTech Connect

    Bradley, D K; Braun, D G; Glendinning, S G; Edwards, M J; Milovich, J L; Sorce, C M; Collins, G W; Haan, S W; Page, R H

    2006-10-30

    The Rayleigh-Taylor (RT) instability is an important factor in bounding the performance envelope of ignition targets. This paper describes an experiment for ablative RT instability that for the first time achieves growth factors close to those expected to occur in ignition targets at the National Ignition Facility (NIF). The large growth allows small seed perturbations to be detected and can be used to place an upper bound on perturbation growth at the ablation front resulting from microstructure in the preferred Be ablator. The experiments were performed on the Omega laser using a halfraum 1.2 mm long by 2 mm diameter with a 75% laser entrance hole. The halfraum was filled with {approx} 1 atm of neopentane to delay gold plasma from closing the diagnostic line of sight down the axis of the halfraum. The ablator was mounted at the base of the halfraum, and was accelerated by a two stepped X-ray pulse consisting of an early time section {approx} 100 eV to emulate the NIF foot followed by an approximately constant {approx} 150 eV drive sustained over an additional 5-7ns. It is this long pulse duration and late time observation that distinguishes the present work from previous experiments, and is responsible for the large growth that is achieved. The growth of a 2D sinusoidal perturbation machined on the drive side of the ablator was measured using face-on radiography. The diagnostic view remained open until {approx} 11 ns with maximum growth factors measured to be {approx} 200. The trajectory of the ablator was measured using streaked backlit radiography. The design and analysis of the experiments is described, and implications for experiments on ignition target ablators are discussed.

  8. Stable and high-speed SiC bulk growth without dendrites by the HTCVD method

    NASA Astrophysics Data System (ADS)

    Tokuda, Yuichiro; Makino, Emi; Sugiyama, Naohiro; Kamata, Isaho; Hoshino, Norihiro; Kojima, Jun; Hara, Kazukuni; Tsuchida, Hidekazu

    2016-08-01

    We investigate growth conditions to obtain high-quality SiC bulk crystals by the High-Temperature Chemical Vapor Deposition (HTCVD) method. Formation of dendrite crystals, which sometimes occurs on the growth front and degrades the material quality, is raised as an issue. We find that a bulk crystal growth under a high vertical temperature gradient, where the temperature of the back side of the bulk crystal is much lower than that of the crystal surface, suppresses the formation of dendrite crystals. Under growth conditions with a high temperature gradient, a very high-speed growth of 2.4 mm/h is achieved without the formation of dendrite crystals. Growth of a thick 4H-SiC bulk crystal without the dendrites is demonstrated and the quality of a grown crystal is evaluated.

  9. Gestures maintain spatial imagery.

    PubMed

    Wesp, R; Hesse, J; Keutmann, D; Wheaton, K

    2001-01-01

    Recent theories suggest alternatives to the commonly held belief that the sole role of gestures is to communicate meaning directly to listeners. Evidence suggests that gestures may serve a cognitive function for speakers, possibly acting as lexical primes. We observed that participants gestured more often when describing a picture from memory than when the picture was present and that gestures were not influenced by manipulating eye contact of a listener. We argue that spatial imagery serves a short-term memory function during lexical search and that gestures may help maintain spatial images. When spatial imagery is not necessary, as in conditions of direct visual stimulation, reliance on gestures is reduced or eliminated.

  10. High temperature effects on rice growth, yield, and grain quality

    USDA-ARS?s Scientific Manuscript database

    Rice (Oryza sativa L.) is a globally important cereal plant, and as a primary source of food it accounts for 35-75% of the calorie intake of more than 3 billion humans. With the likely growth of world’s population towards 10 billion by 2050, the demand for rice will grow faster than for other crops....

  11. Recovery High Schools: Opportunities for Support and Personal Growth for Students in Recovery

    ERIC Educational Resources Information Center

    Finch, Andrew; Wegman, Holly

    2012-01-01

    The time right after treatment for substance abuse is a particularly vulnerable time for adolescents; a time made more difficult by the expectation that they will return to their high school. Traditional high schools are often a high-risk environment for students who are working on maintaining their sobriety. Recovery schools offer an alternative…

  12. Recovery High Schools: Opportunities for Support and Personal Growth for Students in Recovery

    ERIC Educational Resources Information Center

    Finch, Andrew; Wegman, Holly

    2012-01-01

    The time right after treatment for substance abuse is a particularly vulnerable time for adolescents; a time made more difficult by the expectation that they will return to their high school. Traditional high schools are often a high-risk environment for students who are working on maintaining their sobriety. Recovery schools offer an alternative…

  13. Polarization-maintaining property of tapered polarization-maintaining fibers.

    PubMed

    Wang, Xiaozhen; Niedermayer, Graeme; Lin, Ganbin; Lu, Ping; Wang, Baishi; Chen, Liang; Bao, Xiaoyi

    2013-03-10

    Distributed group birefringence of tapered polarization-maintaining fibers (PMFs) is measured by employing a high-resolution optical frequency-domain reflectometry system. Autocorrelation data processing reveals distributed mode coupling between the fast and slow modes and higher-order modes excited by the tapering process along the taper region. The polarization-maintaining property of a tapered PMF is examined by distributed group birefringence along the tapered PMF with a spatial resolution of ~1.25 cm and a polarization-extinction ratio at the fiber taper output over the wavelength range of 1510-1570 nm. With a waist diameter of 80 μm, the polarization state of the launched light is maintained and the birefringence of the tapered PMF is slightly reduced from 3.28×10(-4) to 2.89×10(-4) at the taper waist. For both the waist diameters of 60 and 40 μm, mode coupling is observed in the form of significantly decreased birefringence by a factor of ~10 at the taper waists.

  14. High yields from young-growth ponderosa pine.

    Treesearch

    Edwin L. Mowat

    1947-01-01

    A ponderosa pine stand growing at a net rate of 618 board feet per acre per year may be rather amazing to foresters accustomed to the proverbial slow growth of this species in the virgin forest. Yet that is the average increment for the last 6 years of a 102-year-old even-aged stand on Lookout Mountain in the Pringle Falls Experimental Forest in central Oregon. During...

  15. High-pressure, high-temperature bioreactor for comparing effects of hyperbaric and hydrostatic pressure on bacterial growth.

    PubMed Central

    Nelson, C M; Schuppenhauer, M R; Clark, D S

    1992-01-01

    We describe a high-pressure reactor system suitable for simultaneous hyperbaric and hydrostatic pressurization of bacterial cultures at elevated temperatures. For the deep-sea thermophile ES4, the growth rate at 500 atm (1 atm = 101.29 kPa) and 95 degrees C under hydrostatic pressure was ca. three times the growth rate under hyperbaric pressure and ca. 40% higher than the growth rate at 35 atm. PMID:1622255

  16. Exogenously Applied Plant Growth Regulators Enhance the Morpho-Physiological Growth and Yield of Rice under High Temperature

    PubMed Central

    Fahad, Shah; Hussain, Saddam; Saud, Shah; Hassan, Shah; Ihsan, Zahid; Shah, Adnan N.; Wu, Chao; Yousaf, Muhammad; Nasim, Wajid; Alharby, Hesham; Alghabari, Fahad; Huang, Jianliang

    2016-01-01

    A 2-year experiment was conducted to ascertain the effects of exogenously applied plant growth regulators (PGR) on rice growth and yield attributes under high day (HDT) and high night temperature (HNT). Two rice cultivars (IR-64 and Huanghuazhan) were subjected to temperature treatments in controlled growth chambers and four different combinations of ascorbic acid (Vc), alpha-tocopherol (Ve), brassinosteroids (Br), methyl jasmonates (MeJA), and triazoles (Tr) were applied. High temperature severely affected rice morphology, and also reduced leaf area, above-, and below-ground biomass, photosynthesis, and water use efficiency, while increased the leaf water potential of both rice cultivars. Grain yield and its related attributes except number of panicles, were reduced under high temperature. The HDT posed more negative effects on rice physiological attributes, while HNT was more detrimental for grain formation and yield. The Huanghuazhan performed better than IR-64 under high temperature stress with better growth and higher grain yield. Exogenous application of PGRs was helpful in alleviating the adverse effects of high temperature. Among PGR combinations, the Vc+Ve+MejA+Br was the most effective treatment for both cultivars under high temperature stress. The highest grain production by Vc+Ve+MejA+Br treated plants was due to enhanced photosynthesis, spikelet fertility and grain filling, which compensated the adversities of high temperature stress. Taken together, these results will be of worth for further understanding the adaptation and survival mechanisms of rice to high temperature and will assist in developing heat-resistant rice germplasm in future. PMID:27625658

  17. Effects of High Intensity Training and High Volume Training on Endothelial Microparticles and Angiogenic Growth Factors

    PubMed Central

    Achtzehn, Silvia; Schmitz, Theresa; Bloch, Wilhelm; Mester, Joachim; Werner, Nikos

    2014-01-01

    Aims Endothelial microparticles (EMP) are complex vesicular structures shed from activated or apoptotic endothelial cells. As endurance exercise affects the endothelium, the objective of the study was to examine levels of EMP and angiogenic growth factors following different endurance exercise protocols. Methods 12 subjects performed 3 different endurance exercise protocols: 1. High volume training (HVT; 130 min at 55% peak power output (PPO); 2. 4×4 min at 95% PPO; 3. 4×30 sec all-out. EMPs were quantified using flow cytometry after staining platelet-poor-plasma. Events positive for Annexin-V and CD31, and negative for CD42b, were classified as EMPs. Vascular endothelial growth factor (VEGF), migratory inhibiting factor (MIF) and hepatocyte growth factor (HGF) were determined by ELISA technique. For all these measurements venous blood samples were taken pre, 0′, 30′, 60′ and 180′ after each intervention. Furthermore, in vitro experiments were performed to explore the effect of collected sera on target endothelial functions and MP uptake capacities. Results VEGF and HGF significantly increased after HIT interventions. All three interventions caused a significant decrease in EMP levels post exercise compared to pre values. The sera taken after exercise increased the uptake of EMP in target endothelial cells compared to sera taken under resting conditions, which was shown to be phosphatidylserin-dependent. Increased EMP uptake was associated with an improved protection of target cells against apoptosis. Sera taken prior and after exercise promoted target endothelial cell migration, which was abrogated after inhibition of VEGF. Conclusion Physical exercise leads to decreased EMP levels and promotes a phosphatidylserin-dependent uptake of EMP into target endothelial cells, which is associated with a protection of target cells against apoptosis. PMID:24770423

  18. High-Achieving and Average Students' Reading Growth: Contrasting School and Summer Trajectories

    ERIC Educational Resources Information Center

    Rambo-Hernandez, Karen E.; McCoach, D. Betsy

    2015-01-01

    Much is unknown about how initially high-achieving students grow academically, especially given the measurement issues inherent in assessing growth for the highest performing students. This study compared initially high-achieving and average students' growth in reading (in a cohort of third-grade students from 2,000 schools) over 3 years.…

  19. The Benefits of High School Experiences on Growth in Occupational Status in U.S.

    ERIC Educational Resources Information Center

    Kim, Kyung-Nyun; Passmore, David L.

    2016-01-01

    In this study, we investigated high school graduates' school-to-work transition by considering their post-school occupational skill levels. Using an ordinal growth model analysis, occupational status increased in an arch-shaped curve as the number of years after high school graduation also increased. This growth trajectory was further related to…

  20. High-Achieving and Average Students' Reading Growth: Contrasting School and Summer Trajectories

    ERIC Educational Resources Information Center

    Rambo-Hernandez, Karen E.; McCoach, D. Betsy

    2015-01-01

    Much is unknown about how initially high-achieving students grow academically, especially given the measurement issues inherent in assessing growth for the highest performing students. This study compared initially high-achieving and average students' growth in reading (in a cohort of third-grade students from 2,000 schools) over 3 years.…

  1. The Benefits of High School Experiences on Growth in Occupational Status in U.S.

    ERIC Educational Resources Information Center

    Kim, Kyung-Nyun; Passmore, David L.

    2016-01-01

    In this study, we investigated high school graduates' school-to-work transition by considering their post-school occupational skill levels. Using an ordinal growth model analysis, occupational status increased in an arch-shaped curve as the number of years after high school graduation also increased. This growth trajectory was further related to…

  2. High-Growth Firms and the Future of the American Economy. Kauffman Foundation Research Series: Firm Formation and Economic Growth

    ERIC Educational Resources Information Center

    Stangler, Dane

    2010-01-01

    Into early 2010, more than two years after the recession began, the American economy continues to send out mixed signals with respect to economic recovery: GDP (gross domestic product) growth looks set to recover, while unemployment is projected to remain high for many more years. The most important economic matter facing the country is job…

  3. Analysis of Arabidopsis thaliana root growth kinetics with high temporal and spatial resolution

    PubMed Central

    Yazdanbakhsh, Nima; Fisahn, Joachim

    2010-01-01

    Background Methods exist to quantify the distribution of growth rate over the root axis. However, non-destructive, high-throughput evaluations of total root elongation in controlled environments and the field are lacking in growth studies. A new imaging approach to analyse total root elongation is described. Scope High pixel resolution of the images enables the study of growth in short time intervals and provides high temporal resolution. Using the method described, total root elongation rates are calculated from the displacement of the root tip. Although the absolute root elongation rate changes in response to growth conditions, this set-up enables root growth of Arabidopsis wild-type seedlings to be followed for more than 1 month after germination. The method provides an easy approach to decipher root extension rate and much simpler calculations compared with other methods that use segmental growth to address this question. Conclusions The high temporal resolution allows small modifications of total root elongation growth to be revealed. Furthermore, with the options to investigate growth of various mutants in diverse growth conditions the present tool allows modulations in root growth kinetics due to different biotic and abiotic stimuli to be unravelled. Measurements performed on Arabidopsis thaliana wild-type (Col0) plants revealed rhythms superimposed on root elongation. Results obtained from the starchless mutant pgm, however, present a clearly modified pattern. As expected, deviation is strongest during the dark period. PMID:20421235

  4. Interactions of climate and regional landscape physiography on high elevation forest growth

    NASA Astrophysics Data System (ADS)

    Kelsey, K.; Barger, N. N.; Neff, J. C.

    2014-12-01

    Forests of the western United States are in a period of rapid change, due in part to climate driven changes in life history processes of trees such as growth, establishment, and mortality. These changes in forest condition are of particular concern in the American Southwest where climate conditions are projected to become increasingly hot and dry throughout the next century. While lower elevation trees of the American Southwest are already experiencing decreased radial growth in response to moisture stress, the response of high elevation trees to future climate is highly uncertain. Here we use dendro-climatological techniques to explore the climate-mediated changes in radial tree growth over time in the high elevation forests of southwestern Colorado by sampling 450 Engelmann Spruce and 350 Subalpine Fir from 22 sites across varying aspect, elevation, slope and soil type. Our results indicate variable and frequently opposing growth responses of individuals of the same species to climate variables; 52% of Engelmann Spruce sampled (233 individuals) exhibited positive growth responses to warm summer monthly mean temperatures with the remaining 48% exhibiting negative growth response to warm summer temperatures. We found similarly opposing results for growth response to monthly precipitation and vapor pressure deficit. In this presentation we explore the physiological factors responsible for variable climate-growth relationships within these species. Our results suggest a complex response of high elevation forest growth to climate change, and indicate that efforts to constrain future growth in this region will be contingent on both climatic and local physiographic factors.

  5. Develop and Implement a Computerized System to Collate, Analyze and Maintain Records on All Student Discipline Infractions and Administrative/Teacher Punitive Actions in the Seaford Senior High School.

    ERIC Educational Resources Information Center

    Newman, Daniel G.

    To comply with a 1975 memo from the Office for Civil Rights, the Seaford Senior High School in Seaford, Delaware, was required to maintain records on all student discipline actions. These records consisted of student disciplinary case reports designated by case file numbers. In addition, all discipline actions were to be logged by racial or ethnic…

  6. High temperature slows down growth in tobacco hornworms (Manduca sexta larvae) under food restriction.

    PubMed

    Hayes, Matthew B; Jiao, Lihong; Tsao, Tsu-hsuan; King, Ian; Jennings, Michael; Hou, Chen

    2015-03-01

    When fed ad libitum (AL), ectothermic animals usually grow faster and have higher metabolic rate at higher ambient temperature. However, if food supply is limited, there is an energy tradeoff between growth and metabolism. Here we hypothesize that for ectothermic animals under food restriction (FR), high temperature will lead to a high metabolic rate, but growth will slow down to compensate for the high metabolism. We measure the rates of growth and metabolism of 4 cohorts of 5th instar hornworms (Manduca sexta larvae) reared at 2 levels of food supply (AL and FR) and 2 temperatures (20 and 30 °C). Our results show that, compared to the cohorts reared at 20 °C, the ones reared at 30 °C have high metabolic rates under both AL and FR conditions, but a high growth rate under AL and a low growth rate under FR, supporting this hypothesis.

  7. Epitaxial growth of high quality WO3 thin films

    DOE PAGES

    Leng, X.; Pereiro, J.; Strle, J.; ...

    2015-09-09

    We have grown epitaxial WO3 films on various single-crystal substrates using radio-frequency (RF) magnetron sputtering. While pronounced surface roughness is observed in films grown on LaSrAlO4 substrates, films grown on YAlO3 substrates show atomically flat surfaces, as demonstrated by atomic force microscopy (AFM) and X-ray diffraction (XRD) measurements. The crystalline structure has been confirmed to be monoclinic by symmetric and skew-symmetric XRD. Furthermore, the dependence of the growth modes and the surface morphology on the lattice mismatch is discussed.

  8. High temperature alters the growth reaction of Pottia protonemata

    NASA Astrophysics Data System (ADS)

    Chaban, Ch. I.; Ripetskyj, R. T.; Kordyum, E. L.; Kit, N. A.

    1999-01-01

    Under gravistimulation, dark-grown protonemata of Pottia intermedia revealed negative gravitropism with a growth rate of approximately 28 μm.h-1 at room temperature (20 °C). In 7 days, the protonema formed a bundle of vertically oriented filaments. At an elevated temperature (30 °C), bundles of vertically growing filaments were also formed. However, both filament growth rate and amplitude of the gravicurvature were reduced. Red light (RL) irradiation induced a positive phototropism of most apical protonemal cells at 20 °C. In a following period of darkness, approximately two-thirds of such cells began to grow upward again, recovering their negative gravitropism. RL irradiation at the elevated temperature caused a partial increase in the number of protonemal cells with negative phototropism, but the protonemata did not exhibit negative gravitropism after transfer to darkness. The negative gravitropic reaction was renewed only when protonemata were placed at 20 °C. A dramatic decrease in starch amount in protonemal apical cells, which are sensitive to both gravity and light, occurred at the higher temperature. Such a decrease may be one of the reasons for the inhibition of the protonemal gravireaction at the higher temperature. The observation has a bearing on the starch-statolith theory.

  9. Gestational and Early Postnatal Exposure to Simulated High Altitude Does Not Modify Postnatal Body Mass Growth Trajectory in the Rat

    PubMed Central

    Champin, Graciela M.; Bozzini, Clarisa; Alippi, Rosa M.

    2014-01-01

    Abstract Bozzini, Carlos E, Graciela M. Champin, Clarisa Bozzini, and Rosa M. Alippi. Gestational and Early Postnatal Exposure to Simulated High Altitude Does Not Modify Postnatal Body Mass Growth Trajectory in the Rat. High Alt Med Biol 15:418–421, 2014.—Postnatal hypoxia blunts body mass growth. It is also known that the quality of the fetal environment can influence the subsequent adult phenotype. The main purpose of the study was to determine whether gestational hypoxia and early postnatal hypoxia are able to blunt growth when the offspring is raised under normoxia. Hypobaric hypoxia was induced in simulated high altitude (SHA) chambers in which air was maintained at 380 mmHg (5450 m). Mature Sprague-Dawley rats of both sexes were divided in normoxic (NX) and hypoxic (HX) groups and, in the case of the HX group, maintained for 1 month at 5450 m. Mating was then allowed under NX or HX conditions. Offspring were NX-NX, NX-HX, HX-HX, or HX-NX: the first term indicates NX or HX during both gestation and the first 30 days of life; the second term indicates NX or HX during postnatal life between days 30 and 133. Body mass (g) was measured periodically and body mass growth rate (BMGR, g/d) was estimated between days 33 and 65 of postnatal life. Results can be summarized as follows: 1) BM was significantly higher in NX than in HX rats at weaning; 2) BMGR was not significantly different between NX-NX and HX-NX rats, and between HX-HX and NX-HX animals; and 3) BMGR was significantly higher in rats living under NX conditions than in those living under HX conditions during postnatal life. Data suggest that that hypobaric hypoxia during gestational and early postnatal development of rats does not alter the regulation of body mass growth in rats when compared to that seen under sea-level conditions. PMID:25184739

  10. Maintaining plant safety margins

    SciTech Connect

    Bergeron, P.A.

    1989-01-01

    The Final Safety Analysis Report Forms the basis of demonstrating that the plant can operate safely and meet all applicable acceptance criteria. In order to assure that this continues through each operating cycle, the safety analysis is reexamined for each reload core. Operating limits are set for each reload core to assure that safety limits and applicable acceptance criteria are not exceeded for postulated events within the design basis. These operating limits form the basis for plant operation, providing barriers on various measurable parameters. The barriers are refereed to as limiting conditions for operation (LCO). The operating limits, being influenced by many factors, can change significantly from cycle to cycle. In order to be successful in demonstrating safe operation for each reload core (with adequate operating margin), it is necessary to continue to focus on ways to maintain/improve existing safety margins. Existing safety margins are a function of the plant type (boiling water reactor/pressurized water reactor (BWR/PWR)), nuclear system supply (NSSS) vendor, operating license date, core design features, plant design features, licensing history, and analytical methods used in the safety analysis. This paper summarizes the experience at Yankee Atomic Electric Company (YAEC) in its efforts to provide adequate operating margin for the plants that it supports.

  11. MBE growth technology for high quality strained III-V layers

    NASA Technical Reports Server (NTRS)

    Grunthaner, Frank J. (Inventor); Liu, John K. (Inventor); Hancock, Bruce R. (Inventor)

    1990-01-01

    The III-V films are grown on large automatically perfect terraces of III-V substrates which have a different lattice constant, with temperature and Group III and V arrival rates chosen to give a Group III element stable surface. The growth is pulsed to inhibit Group III metal accumulation of low temperature, and to permit the film to relax to equilibrium. The method of the invention: (1) minimizes starting step density on sample surface; (2) deposits InAs and GaAs using an interrupted growth mode (0.25 to 2 monolayers at a time); (3) maintains the instantaneous surface stoichiometry during growth (As-stable for GaAs, In-stable for InAs); and (4) uses time-resolved RHEED to achieve aspects (1) through (3).

  12. MBE growth technology for high quality strained III-V layers

    NASA Technical Reports Server (NTRS)

    Grunthaner, Frank J. (Inventor); Liu, John K. (Inventor); Hancock, Bruce R. (Inventor)

    1992-01-01

    III-V films are grown on large automatically perfect terraces of III-V substrates which have a different lattice constant, with temperature and Group II and V arrival rates chosen to give a Group III element stable surface. The growth is pulsed to inhibit Group III metal accumulation to low temperature, and to permit the film to relax to equilibrium. The method of the invention 1) minimizes starting step density on sample surface; 2) deposits InAs and GaAs using an interrupted growth mode (0.25 to 2 mono-layers at a time); 3) maintains the instantaneous surface stoichiometry during growth (As-stable for GaAs, In-stable for InAs); and 4) uses time-resolved RHEED to achieve aspects (1)-14 (3).

  13. Heteroepitaxial growth of highly oriented diamond on cubic silicon carbide

    SciTech Connect

    Kawarada, H.; Wild, C.; Herres, N.; Locher, R.; Koidl, P.; Nagasawa, H.

    1997-04-01

    We have deposited epitaxial diamond films with very low angular spread on epitaxial {beta}-phase silicon carbide layers on silicon (001) substrates. From x-ray rocking curve measurements, half-widths of the angular spread of the crystal orientation as low as 0.6{degree} have been determined, which is the smallest value ever reported in heteroepitaxial diamond films and appears to be smaller than those of the {beta}-phase silicon carbide underlayers. The film surface exhibits a roughness of about 100 nm with very few discernible boundaries due to misorientation. The optimization of the bias-enhanced nucleation process and the control of selective growth are the main factors for the improvement of the crystallinity. {copyright} {ital 1997 American Institute of Physics.}

  14. Credit Recovery and Proficiency-Based Credit: Maintaining High Expectations While Providing Flexibility. The Progress of Education Reform. Volume 12, Number 3

    ERIC Educational Resources Information Center

    Zinth, Jennifer Dounay

    2011-01-01

    Improving high school graduation rates has become the focus of virtually every high school, district and state nationwide, as dropout rates in many areas remain unacceptably high. As 80-90% of students voice the expectation that they will go to college (and federal labor projections support the need for a more educated workforce), greater numbers…

  15. Developing a Growth Mindset among High School Students. Practitioner Brief

    ERIC Educational Resources Information Center

    National Center on Scaling Up Effective Schools, 2014

    2014-01-01

    The National Center on Scaling Up Effective Schools (NCSU) spent the 2011-12 school year conducting intensive case studies of four Fort Worth, Texas, high schools to understand what differentiates higher-performing from lower-performing schools. It was found that high schools can address gaps in student achievement, especially with traditionally…

  16. Electronic Equipment Maintainability Data

    DTIC Science & Technology

    1980-01-01

    MISSION CRITICALITY HIGH MISSION CRITICALITY HIGH DESIGN APPROACH DESIGN APPROACH SURVEILLANCE/SEARCH SURVEILLANCE/SEARCH TRACKING TRACKING ECCN ECCM...CRITICALITY NIGH DESIGN APPROACH DESIGN APPROACH SURVEILLANCE/SEARCH SURVEILLANCE/SEARCH TRACKING TRACKING ECCM ECCN MULT ICHANNEL/MULTIFREQUENCY

  17. High frequency ultrasound imaging of the growth and development of the normal chick embryo.

    PubMed

    Schellpfeffer, Michael A; Bolender, David L; Kolesari, Gary L

    2007-05-01

    The purpose of this study is to delineate with high frequency ultrasound imaging the normal growth and development of the chick embryo throughout its incubation period. White Leghorn chick embryos were imaged through an opening in the egg air cell from incubation day 0-19 (Hamburger & Hamilton stage 1-45) using a 13 MHz clinical high frequency linear small parts transducer. Multiple anatomic growth parameters were measured. Normal growth was confirmed with Hamburger and Hamilton staging. A timeline was constructed showing when each anatomic growth parameter could be visualized. Means and standard deviations of each parameter were plotted against incubation days studied to create nomograms and numerical tables of normal growth and development of the chick embryo. With this set of data, abnormal growth and development of the chick embryo can now be assessed.

  18. ADAS Update and Maintainability

    NASA Technical Reports Server (NTRS)

    Watson, Leela R.

    2010-01-01

    Since 2000, both the National Weather Service Melbourne (NWS MLB) and the Spaceflight Meteorology Group (SMG) have used a local data integration system (LOIS) as part of their forecast and warning operations. The original LOIS was developed by the Applied Meteorology Unit (AMU) in 1998 (Manobianco and Case 1998) and has undergone subsequent improvements. Each has benefited from three-dimensional (3-D) analyses that are delivered to forecasters every 15 minutes across the peninsula of Florida. The intent is to generate products that enhance short-range weather forecasts issued in support of NWS MLB and SMG operational requirements within East Central Florida. The current LDIS uses the Advanced Regional Prediction System (ARPS) Data Analysis System (AD AS) package as its core, which integrates a wide variety of national, regional, and local observational data sets. It assimilates all available real-time data within its domain and is run at a finer spatial and temporal resolution than current national or regional-scale analysis packages. As such, it provides local forecasters with a more comprehensive understanding of evolving fine-scale weather features. Over the years, the LDIS has become problematic to maintain since it depends on AMU-developed shell scripts that were written for an earlier version of the ADAS software. The goals of this task were to update the NWS MLB/SMG LDIS with the latest version of ADAS, incorporate new sources of observational data, and upgrade and modify the AMU-developed shell scripts written to govern the system. In addition, the previously developed ADAS graphical user interface (GUI) was updated. Operationally, these upgrades will result in more accurate depictions of the current local environment to help with short-range weather forecasting applications, while also offering an improved initialization for local versions of the Weather Research and Forecasting (WRF) model used by both groups.

  19. Ettlia sp. YC001 showing high growth rate and lipid content under high CO2.

    PubMed

    Yoo, Chan; Choi, Gang-Guk; Kim, Sun-Chang; Oh, Hee-Mock

    2013-01-01

    Over 100 green-colored colonies were isolated from environmental samples when cultivating on a BG11 agar medium, and 4 strains showing different morphologies were selected based on light microscopic observation. Among these strains, the microalgal species with the highest growth rate under 10% CO(2) was identified as Ettlia sp. YC001 using an 18S rDNA-based phylogenetic analysis and morphological comparison. The highest cell density of 3.10 g/L (based on dry cell weight) and biomass productivity of 0.19 g/L/d were obtained under 5% CO(2) after 16 days. The lipid content and productivity were also up to 42% of the dry cell weight and 80.0mg/L/d, respectively. The color of the Ettlia sp. YC001 culture changed from green to red after a month due to the accumulation of certain carotenoids. Therefore, it would seem that Ettlia sp. YC001 is appropriate for mitigating CO(2) due to its high biomass productivity, and a suitable candidate for producing biodiesel and high-value products.

  20. Perturbative growth of high-multiplicity W, Z and Higgs production processes at high energies

    NASA Astrophysics Data System (ADS)

    Khoze, Valentin V.

    2015-03-01

    Using the classical recursion relations we compute scattering amplitudes in a spontaneously broken Gauge-Higgs theory into final states involving high multiplicities of massive vector bosons and Higgs bosons. These amplitudes are computed in the kinematic regime where the number of external particles n is ≫ 1 and their momenta are non-relativistic. Our results generalise the previously known expressions for the amplitudes on the multi-particle thresholds to a more non-trivial kinematic domain. We find that the amplitudes in spontaneously broken gauge theories grow factorially with the numbers of particles produced, and that this factorial growth is only mildly affected by the energy-dependent formfactor computed in the non-relativistic limit. This is reminiscent of the behaviour previously found in massive scalar theories. Cross sections are obtained by integrating the amplitudes squared over the non-relativistic phase-space and found to grow exponentially at energy scales in a few hundred TeV range if we use the non-relativistic high multiplicity limit. This signals a breakdown of perturbation theory and indicates that the weak sector of the Standard Model becomes effectively strongly coupled at these multiplicities. There are interesting implications for the next generation of hadron colliders both for searches of new physics phenomena beyond and within the Standard Model.

  1. Ascorbic-acid-assisted growth of high quality M@ZnO: a growth mechanism and kinetics study

    NASA Astrophysics Data System (ADS)

    Yang, Yun; Han, Shuhua; Zhou, Guangju; Zhang, Lijie; Li, Xingliang; Zou, Chao; Huang, Shaoming

    2013-11-01

    We present a general route for synthesizing M@ZnO nanoparticles (NPs) by using ascorbic acid (AA) to induce deposition of ZnO on various shaped and structured cationic-surfactant-capped NP surfaces (noble, magnetic, semiconductor, rod-like, spherical, cubic, dendrite, alloy, core@shell). The results show that the complexing (AA and Zn2+) and cooperative effects (AA and CTAB) play important roles in the formation of polycrystalline ZnO shells. Besides, the growth kinetics of M@ZnO was systematically studied. It was found that the slow growth rate favors the successful formation of uniform core@ZnO NPs with relatively loose shells. An appropriate growth rate allows achieving high quality M@ZnO NPs with dense shells. However, very fast growth causes significant additional nucleation and the formation of pure ZnO NPs. This general method is suitable for preparing M@ZnO using seed NPs prepared in both water and organic phases. It might be an alternative route for functionalizing NPs for bioapplications (ZnO is biocompatible), modulating material properties as designed, or synthesizing template materials for building other nanostructures.We present a general route for synthesizing M@ZnO nanoparticles (NPs) by using ascorbic acid (AA) to induce deposition of ZnO on various shaped and structured cationic-surfactant-capped NP surfaces (noble, magnetic, semiconductor, rod-like, spherical, cubic, dendrite, alloy, core@shell). The results show that the complexing (AA and Zn2+) and cooperative effects (AA and CTAB) play important roles in the formation of polycrystalline ZnO shells. Besides, the growth kinetics of M@ZnO was systematically studied. It was found that the slow growth rate favors the successful formation of uniform core@ZnO NPs with relatively loose shells. An appropriate growth rate allows achieving high quality M@ZnO NPs with dense shells. However, very fast growth causes significant additional nucleation and the formation of pure ZnO NPs. This general method is

  2. Higher Ammonium Transamination Capacity Can Alleviate Glutamate Inhibition on Winter Wheat (Triticum aestivum L.) Root Growth under High Ammonium Stress.

    PubMed

    Wang, Feng; Gao, Jingwen; Liu, Yang; Tian, Zhongwei; Muhammad, Abid; Zhang, Yixuan; Jiang, Dong; Cao, Weixing; Dai, Tingbo

    2016-01-01

    Most of the studies about NH4+ stress mechanism simply address the effects of free NH4+, failing to recognize the changed nitrogen assimilation products. The objective of this study was to elucidate the effects of glutamate on root growth under high ammonium (NH4+) conditions in winter wheat (Triticum aestivum L.). Hydroponic experiments were conducted using two wheat cultivars, AK58 (NH4+-sensitive) and Xumai25 (NH4+-tolerant) with either 5 mM NH4+ nitrogen (AN) as stress treatment or 5 mM nitrate (NO3-) nitrogen as control. To evaluate the effects of NH4+-assimilation products on plant growth, 1 μM L-methionine sulfoximine (MSO) (an inhibitor of glutamine synthetase (GS)) and 1 mM glutamates (a primary N assimilation product) were added to the solutions, respectively. The AN significantly reduced plant biomass, total root length, surface area and root volume in both cultivars, but less effect was observed in Xumai25. The inhibition effects were alleviated by the application of MSO but strengthened by the application of glutamate. The AN increased the activities of GS, glutamate dehydrogenase (GDH) in both cultivars, resulting in higher glutamate contents. However, its contents were decreased by the application of MSO. Compared to AK58, Xumai25 showed lower glutamate contents due to its higher activities of glutamic-oxaloacetic transaminase (GOT) and glutamic-pyruvic transaminase (GPT). With the indole-3-acetic acid (IAA) contents decreasing in roots, the ratio of shoot to root in IAA was increased, and further increased by the application of glutamate, and reduced by the application of MSO, but the ratio was lower in Xumai25. Meanwhile, the total soluble sugar contents and its root to shoot ratio also showed similar trends. These results indicate that the NH4+-tolerant cultivar has a greater transamination ability to prevent glutamate over-accumulation to maintain higher IAA transport ability, and consequently promoted soluble sugar transport to roots, further

  3. Maintaining the unmethylated state

    PubMed Central

    2013-01-01

    Background A remarkable correspondence exists between the cytogenetic locations of the known fragile sites and frequently reported sites of hypermethylation. The best-known features of fragile sites are sequence motifs that are prone to the spontaneous formation of a non-B DNA structure. These facts, coupled with the known enzymological specificities of DNA methyltransferase 1 (DNMT1), the ATP-dependent and actin-dependent helicases, and the ten-eleven translocation (TET) dioxygenases, suggest that these enzymes are involved in an epigenetic cycle that maintains the unmethylated state at these sites by resolving non-B structure, preventing both the sequestration of DNA methyltransferases (DNMTs) and hypermethylation in normal cells. Presentation of the hypothesis The innate tendency of DNA sequences present at fragile sites to form non-B DNA structures results in de novo methylation of DNA at these sites that is held in check in normal cells by the action of ATP-dependent and actin-dependent helicases coupled with the action of TET dioxygenases. This constitutes a previously unrecognized epigenetic repair cycle in which spontaneously forming non-B DNA structures formed at fragile sites are methylated by DNMTs as they are removed by the action of ATP-dependent and actin-dependent helicases, with the resulting nascent methylation rendered non-transmissible by TET dioxygenases. Testing the hypothesis A strong prediction of the hypothesis is that knockdown of ATP-dependent and actin-dependent helicases will result in enhanced bisulfite sensitivity and hypermethylation at non-B structures in multiple fragile sites coupled with global hypomethylation. Implications of the hypothesis A key implication of the hypothesis is that helicases, like the lymphoid-specific helicase and alpha thalassemia/mental retardation syndrome X-linked helicase, passively promote accurate maintenance of DNA methylation by preventing the sequestration of DNMTs at sites of unrepaired non-B DNA

  4. Polyamines regulate cell growth and cellular methylglyoxal in high-glucose medium independently of intracellular glutathione.

    PubMed

    Kwak, Min-Kyu; Lee, Mun-Hyoung; Park, Seong-Jun; Shin, Sang-Min; Liu, Rui; Kang, Sa-Ouk

    2016-03-01

    Polyamines can presumably inhibit protein glycation, when associated with the methylglyoxal inevitably produced during glycolysis. Herein, we hypothesized a nonenzymatic interaction between putrescine and methylglyoxal in putrescine-deficient or -overexpressing Dictyostelium cells in high-glucose medium, which can control methylglyoxal production. Putrescine was essentially required for growth rescue accompanying methylglyoxal detoxification when cells underwent growth defect and cell cycle G1-arrest when supplemented with high glucose. Furthermore, methylglyoxal regulation by putrescine seemed to be a parallel pathway independent of the changes in cellular glutathione content in high-glucose medium. Consequently, we suggest that Dictyostelium cells need polyamines for normal growth and cellular methylglyoxal regulation.

  5. Soy protein isolate inhibits high-Ffat diet-induced senescence pathways in osteoblasts to maintain bone acquisition in male rats

    USDA-ARS?s Scientific Manuscript database

    Chronic consumption by experimental animals of a typical Western diet high in saturated fats and cholesterol during postnatal life has been demonstrated to impair skeletal development. However, underlying mechanism by which high fat, energy dense diets affect bone forming cell phenotypes is poorly u...

  6. Planning for Lutheran High Schools. Maintaining Fiscal Responsibility. Part One--Accounting. Part Two--Budgeting. Part Three--Five-Year Budget Projection. H 10.

    ERIC Educational Resources Information Center

    Lutheran Church, Missouri Synod, St. Louis, MO.

    This handbook has been prepared to assist new and existing Lutheran high schools. Three major portions of a high school financial system are described: accounting, budgeting, and five-year budget projections. The chart of accounts is described in detail in the accounting section and in the appendices. In order to develop some consistency in the…

  7. High-Resolution Transmission Electron Microscopy Observation of Colloidal Nanocrystal Growth Mechanisms using Graphene Liquid Cells

    SciTech Connect

    Yuk, Jong Min; Park, Jungwon; Ercius, Peter; Kim, Kwanpyo; Hellebusch, Danny J.; Crommie, Michael F.; Lee, Jeong Yong; Zettl, A.; Alivisatos, A. Paul

    2011-12-12

    We introduce a new type of liquid cell for in-situ electron microscopy based upon entrapment of a liquid film between layers of graphene. We employ this cell to achieve high-resolution imaging of colloidal platinum nanocrystal growth. The ability to directly image and resolve critical steps at atomic resolution provides new insights into nanocrystal coalescence and reshaping during growth.

  8. Markers for hepatitis A, B and C in methadone maintained patients: an unexpectedly high co-infection with silent hepatitis B.

    PubMed

    Bart, Gavin; Piccolo, Paola; Zhang, Linqi; Jacobson, Ira; Schaefer, Robert A; Kreek, Mary Jeanne

    2008-04-01

    To determine the prevalence of hepatitis A, B and C viruses in patients attending a methadone maintenance clinic in New York City. Cross-sectional. The Adult Services Clinic of Weill Cornell Medical College, an urban hospital-affiliated methadone program. Former heroin addicted adults (n = 103) on methadone maintenance therapy. Markers for hepatitis A virus [HAV immunoglobulin M (IgM) and imunoglobulin G (IgG)], hepatitis B [hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (HBsAb) and hepatitis B core antibody (HBcAb)] and hepatitis C virus (HCVAb). Serum alanine aminotransferase (ALT) and quantitative HCV RNA were also obtained. Qualitative detection of HBV DNA and HCV genotype were obtained in a subset of subjects. More than 40% of subjects had markers for all three viruses. HCVAb was the most prevalent (83.5%), followed by HBcAb (65.0%), HAV IgG (46.1%) and HBsAb (41.1%). Hepatitis C RNA was detected in 70.6% of HCVAb positive subjects. While no subject had HBsAg, HBV DNA was detected in 26.4% of subjects who underwent this measure; all (n = 20) had HBcAb as their only HBV marker. The presence of HBV DNA did not influence ALT. Subjects with HCV RNA had higher ALTs than those without HCV RNA. Most methadone-maintained subjects had at least one marker for viral hepatitis, with 41.8% having markers for HAV, HBV and HCV. A quarter of subjects had silent HBV infection, defined as the presence of HBV DNA in the absence of HBsAg. These subjects should be considered infectious and pose a public health risk.

  9. Quality of life attributes spur growth in high amenity communities.

    Treesearch

    Linda. Kruger

    2006-01-01

    Many communities located near high amenity public lands are growing rapidly (McGranahan 2005). The phenomenon behind the change is amenity migration-the relocation of people to areas rich in environmental and cultural resources and recreation opportunities (Johnson and Beale 2002, McCool and Kruger 2003; Green, Deller, and Marcouiller 2006). Migrants often visit an...

  10. Growth and demography of Pinaleno high elevation forests

    Treesearch

    Christopher O' Connor; Donald A. Falk; Ann M. Lynch; Craig P. Wilcox; Thomas W. Swetnam; Tyson L. Swetnam

    2010-01-01

    The project goal is to understand how multiple disturbance events including fire, insect outbreaks, and climate variability interact in space and time, and how they combine to influence forest species composition, spatial structure, and tree population dynamics in high elevation forests of the Pinaleno Mountains. Information from each of these components is needed in...

  11. Plate-only open door laminoplasty maintains stable spinal canal expansion with high rates of hinge union and no plate failures.

    PubMed

    Rhee, John M; Register, Bradley; Hamasaki, Takahiko; Franklin, Betty

    2011-01-01

    occur in any case in which 2 laminar screws had been placed. Plate-only laminoplasty provided stable reconstruction of an expanded laminar arch with no failures, dislodgements, adverse neurologic consequences, or premature closures in 217 levels. Ninety-three percent of hinges demonstrated radiographic union at 12 months, and even those that did not heal by CT scan criteria maintained patent expansion of the spinal canal without adverse neurologic consequences. Supplemental bone graft does not appear necessary when plated laminoplasty is performed.

  12. Increased fibroblast growth factor 21 expression in high-fat diet-sensitive non-human primates (Macaca mulatta).

    PubMed

    Nygaard, E B; Møller, C L; Kievit, P; Grove, K L; Andersen, B

    2014-02-01

    Fibroblast growth factor 21 (FGF21) is a metabolic regulator of glucose and lipid metabolism. The physiological role of FGF21 is not yet fully elucidated, however, administration of FGF21 lowers blood glucose in diabetic animals. Moreover, increased levels of FGF21 are found in obese and diabetic rodents and humans compared with lean/non-diabetic controls. Adult male rhesus macaque monkeys were chronically maintained on a high-fat diet (HFD) or a standard diet (control, CTR). Plasma levels of FGF21, triglycerides and cholesterol were measured and body weight was record. Glucose-stimulated insulin secretion (GSIS) and glucose clearance was determined during an intravenous glucose tolerance test. Furthermore, expression of FGF21 and its receptors were determined in liver, pancreas, three white adipose tissues (WATs) and two skeletal muscles. A cohort of the high-fat fed monkeys responded to the HFD with increasing body weight, plasma lipids, total cholesterol, GSIS and decreased glucose tolerance. These monkeys were termed HFD sensitive. Another cohort of monkeys did not become obese and maintained normal insulin sensitivity. These animals were defined as HFD resistant. Plasma FGF21 levels were significantly increased in all HFD fed monkeys compared with the CTR group. The HFD-sensitive monkeys showed a significant increase in FGF21 mRNA expression in all examined tissues compared with CTR, whereas FGF21 expression in the HFD-resistant group was only increased in the liver, pancreas and the retroperitoneal WAT. In the WAT, the co-receptor β-klotho was downregulated in the HFD-sensitive monkeys compared with the HFD-resistant group. This study demonstrates that HFD changes FGF21 and FGF21 receptor expression in a tissue-specific manner in rhesus monkeys; differential regulation is moreover observed between HFD-sensitive and -resistant monkeys. Monkeys that maintain normal levels of the FGF21 co-receptor β-klotho in the WAT on HFD were protected toward development of

  13. Downward regulation of photosynthesis and growth at high CO sub 2 levels

    SciTech Connect

    Idso, S.B.; Kimball, B.A. )

    1991-07-01

    Numerous photosynthesis and growth measurements of sour orange (Citrus aurantium L.) trees maintained in ambient air and air enriched with an extra 300 microliters per liter of Co{sub 2} have revealed the Co{sub 2}-enriched trees to have consistently sequestered approximately 2.8 times more carbon than the control trees over a period of three full years. Under field conditions in the natural environment, plants may not experience the downward regulation of photosynthetic capacity typically observed in long-term CO{sub 2} enrichment experiments with plants growing in pots.

  14. Understanding the mathematics and science achievement and growth trajectories of high ability high school students using hierarchical linear modeling

    NASA Astrophysics Data System (ADS)

    Belen-Ferrer, Bellasanta

    2009-12-01

    This study used longitudinal data and individual, family, and academic-related matriculation variables to examine trends in initial status and growth trajectories in overall academics, mathematics, and science achievement among 224 high ability high school Asian students. Results indicate that females have an advantage in both initial status and growth rates in overall academics and science. None of the family variables entered in the models were found to be significantly related to overall academics grade point average. All available matriculation variables entered into the models explained less than or at most about half the variance in initial achievement status and growth rate in overall academics and science but not in mathematics. These results strongly imply that other factors, notably family and school and/or classroom-related variables, not measured by the ones used in the models could explain the expected variance in initial status and growth rate of the students especially in Mathematics.

  15. High Growth Rate Deposition of Hydrogenated Amorphous Silicon-Germanium Films and Devices Using ECR-PECVD

    SciTech Connect

    Liu, Yong

    2002-01-01

    Hydrogenated amorphous silicon germanium films (a-SiGe:H) and devices have been extensively studied because of the tunable band gap for matching the solar spectrum and mature the fabrication techniques. a-SiGe:H thin film solar cells have great potential for commercial manufacture because of very low cost and adaptability to large-scale manufacturing. Although it has been demonstrated that a-SiGe:H thin films and devices with good quality can be produced successfully, some issues regarding growth chemistry have remained yet unexplored, such as the hydrogen and inert-gas dilution, bombardment effect, and chemical annealing, to name a few. The alloying of the SiGe introduces above an order-of-magnitude higher defect density, which degrades the performance of the a-SiGe:H thin film solar cells. This degradation becomes worse when high growth-rate deposition is required. Preferential attachment of hydrogen to silicon, clustering of Ge and Si, and columnar structure and buried dihydride radicals make the film intolerably bad. The work presented here uses the Electron-Cyclotron-Resonance Plasma-Enhanced Chemical Vapor Deposition (ECR-PECVD) technique to fabricate a-SiGe:H films and devices with high growth rates. Helium gas, together with a small amount of H2, was used as the plasma species. Thickness, optical band gap, conductivity, Urbach energy, mobility-lifetime product, I-V curve, and quantum efficiency were characterized during the process of pursuing good materials. The microstructure of the a-(Si,Ge):H material was probed by Fourier-Transform Infrared spectroscopy. They found that the advantages of using helium as the main plasma species are: (1) high growth rate--the energetic helium ions break the reactive gas more efficiently than hydrogen ions; (2) homogeneous growth--heavy helium ions impinging on the surface promote the surface mobility of the reactive radicals, so that heteroepitaxy growth as clustering of Ge and Si, columnar structure are

  16. Biophysical Properties and Oxygenation Potential of High-Molecular-Weight Glutaraldehyde-Polymerized Human Hemoglobins Maintained in the Tense and Relaxed Quaternary States

    PubMed Central

    Zhang, Ning; Jia, Yiping; Chen, Guo; Cabrales, Pedro

    2011-01-01

    Recent clinical evaluation of commercial glutaraldehyde-polymerized hemoglobins (PolyHbs) as transfusion solutions has demonstrated several adverse side effects. Chief among these is the hypertensive effect. Fortunately, previous studies have shown that the hypertensive effect can be attenuated by removing free hemoglobin (Hb) and low-molecular-weight (low-MW) PolyHbs from the PolyHb mixture. In this work, polymerized human Hb (PolyhHb) solutions were synthesized in two distinct quaternary states with high MW and subjected to extensive diafiltration to remove free Hb and low-MW PolyhHb components (<500 kDa). The resultant PolyhHb solutions possessed high MW, distinct quaternary state, distinct reactivities with O2 and CO, similar NO deoxygenating rate constants, distinct autoxidation rate constants, high viscosity, and low colloid osmotic pressure. To preliminarily assess the ability of PolyhHb solutions to oxygenate surrounding tissues fed by a blood vessel, we evaluated the ability of PolyhHbs to transport O2 to cultured hepatocytes in a mathematical model of a hollow fiber bioreactor. The structure of individual hollow fibers in the bioreactor is similar to that of a blood vessel and provides an easy way to assess the oxygenation potential of PolyhHbs without the need for expensive and time-consuming animal studies. It was observed that PolyhHbs with low O2 affinities were more effective in oxygenating cultured hepatocytes inside the bioreactor than high O2 affinity PolyhHbs. Taken together, our results show that it is possible to synthesize high-MW PolyhHbs with no free Hb and low-MW PolyhHb components that are capable of transporting O2 to cultured cells/tissues. PMID:20979534

  17. Arrest at metaphase of meiosis I in starfish oocytes in the ovary is maintained by high CO2 and low O2 concentrations in extracellular fluid.

    PubMed

    Moriwaki, Kei; Nakagawa, Takako; Nakaya, Fumio; Hirohashi, Noritaka; Chiba, Kazuyoshi

    2013-11-01

    During the spawning process in starfish, oocytes are arrested at metaphase of meiosis I (MI) within the ovary, and reinitiate meiosis only after they have been released into the seawater. However, this arrest does not occur if the ovary is removed from the animal. As the pH of the coelomic fluid is buffered by CO2/H(+)/HCO3(-), we investigated the involvement of gas concentrations in MI arrest. In vivo, the CO2 level in the coelomic fluid was high (∼1.5% vs. 0.04% in air) and the O2 level was low (0.1-1.0% vs. ∼20% in air). When these gas conditions were reproduced in isolated coelomic fluid or seawater, ovarian oocytes arrested at MI, just as in vivo. Isolated oocytes from the ovary required the similar high CO2 and low O2 level to remain arrested in MI and had an intracellular pH of ∼6.9. Intracellular pH increased to ∼7.3 when oocytes were transferred to seawater equilibrated with air, a condition that mimics that of spawning. We used ammonium acetate to clamp intracellular pH at different levels and found that MI arrest occurred when intracellular pH was ∼6.9. Our results support the idea that high CO2 and low O2 in the ovarian environment lead to low intracellular pH and MI arrest, while spawning into the seawater with low CO2 and high O2 results in high intracellular pH and release from MI arrest. The biological significance of MI arrest is that oocytes are spawned into seawater at the optimal physiological state of MI when the least polyspermy occurs.

  18. Maintaining network security: how macromolecular structures cross the peptidoglycan layer.

    PubMed

    Scheurwater, Edie M; Burrows, Lori L

    2011-05-01

    Peptidoglycan plays a vital role in bacterial physiology, maintaining cell shape and resisting cellular lysis from high internal turgor pressures. Its integrity is carefully maintained by controlled remodeling during growth and division by the coordinated activities of penicillin-binding proteins, lytic transglycosylases, and N-acetylmuramyl-l-alanine amidases. However, its small pore size (∼2 nm) and covalently closed structure make it a formidable barrier to the assembly of large macromolecular cell-envelope-spanning complexes involved in motility and secretion. Here, we review the strategies used by Gram-negative bacteria to assemble such macromolecular complexes across the peptidoglycan layer, while preserving its essential structural role. In addition, we discuss evidence that suggests that peptidoglycan can be integrated into cell-envelope-spanning complexes as a structural and functional extension of their architecture.

  19. Kinetics of inclusion body production in batch and high cell density fed-batch culture of Escherichia coli expressing ovine growth hormone.

    PubMed

    Panda, A K; Khan, R H; Rao, K B; Totey, S M

    1999-10-08

    A process for maximizing the volumetric productivity of recombinant ovine growth hormone (r-oGH) expressed in Escherichia coli during high cell density fermentation process has been devised. Kinetics of r-oGH expression as inclusion bodies and its effect on specific growth rates of E. coli cells were monitored during batch fermentation process. It was observed that during r-oGH expression in E. coli, the specific growth rate of the culture became an intrinsic property of the cells which reduced in a programmed manner upon induction. Nutrient feeding during protein expression phase of the fed-batch process was designed according to the reduction in specific growth rate of the culture. By feeding yeast extract along with glucose during fed-batch operation, high cell growth with very little accumulation of acetic acid was observed. Use of yeast extract helped in maintaining high specific cellular protein yield which resulted in high volumetric productivity of r-oGH. In 16 h of fed-batch fermentation, 3.2 g l-1 of r-oGH were produced at a cell OD of 124. This is the highest concentration of r-oGH reported to date using E. coli expression system. The volumetric productivity of r-oGH was 0.2 g l-1 h-1, which is also the highest value reported for any therapeutic protein using IPTG inducible expression system in a single stage fed-batch process.

  20. Installing and maintaining gear pumps

    SciTech Connect

    Whitmire, K.

    1996-03-01

    While not as common as centrifugal pumps in the CPI, gear pumps play important roles in handling many of today`s more difficult-to-pump fluids. Because they operate at lower speeds -- generally, 900 rpm or less -- their seals and bearings tend to last longer than those of centrifugal models. In addition, unlike centrifugal pumps, gear pumps` flows are independent of their systems` pressure curves, and they can handle a wider range of viscosities. Although high-flow, low-head applications remain the domain of centrifugal pumps, the use of gear pumps is increasing in the chemical process industries (CPI). While some application boundaries between gears and centrifugals are blurring, there are some crucial differences between the way the two are operated and maintained -- for example, where pressure relief is concerned. This article provides a general summary of gear pump characteristics and applications, highlighting critical aspects of installation, operation and maintenance.

  1. Measurements of the growth and coagulation of soot particles in a high-pressure shock tube

    SciTech Connect

    Kellerer, H.; Koch, R.; Wittig, S.

    2000-01-01

    The advantage of well-defined experimental conditions in shock tubes has been used to investigate the growth and coagulation of soot particles at high pressures. The measurements have been made for fuel-rich oxidation and pyrolysis of different hydrocarbons behind the reflected shock at pressures between 10 and 60 bar and temperatures between 1,500 and 2,300 K. In addition to soot volume fraction, time-resolved scattering measurements yielded particle diameters and number densities; all these give insight into both surface growth and coagulation at enhanced pressures. The temperature behind the reflected shock was monitored by two-color pyrometry. Soot growth was characterized by induction periods and soot growth rates. At low final soot yields, the growth rate of soot depends on the square of the carbon concentration. At high soot yields, reduced growth rates of soot volume fraction were observed and can be attributed to a lack of growth species. At constant carbon concentration no pressure dependence of soot volume fraction could be found. Particle diameters between 15 and 40 nm were measured. The number density of particles was found to increase strongly with soot volume fraction. Calculated and measured particle number densities agree well during early soot growth. However, at longer times the experiments reveal coagulation rates which are significantly smaller than predicted. This behavior indicates that collisions of deactivated soot particles are characterized by sticking probabilities lower than unity. A correlation for the sticking probability has been established to match both the experimental results and calculations.

  2. Effects of enzyme supplementation of a total mixed ration on microbial fermentation in continuous culture, maintained at high and low pH.

    PubMed

    Colombatto, D; Hervás, G; Yang, W Z; Beauchemin, K A

    2003-10-01

    A dual-flow continuous culture system was used to investigate the effects of pH and addition of an enzyme mixture to a total mixed ration (TMR) on fermentation, nutrient digestion, and microbial protein synthesis. A 4 x 4 Latin square design with a factorial arrangement of treatments was used, with four 9-d periods consisting of 6 d for adaptation and 3 d for measurements. Treatments were as follows: 1) high pH with control TMR, 2) high pH with TMR treated with enzyme, 3) low pH with control TMR, and 4) low pH with TMR treated with enzyme. Ranges of pH were 6.0 to 6.6 and 5.4 to 6.0 for high and low, respectively. Fermenters were fed twice daily a TMR consisting of 30% alfalfa hay, 30% corn silage, and 40% rolled corn (DM basis). The silage was milled fresh and the TMR was fed to the fermenters in fresh form (64% DM). The enzyme mixture was a commercial product of almost exclusive protease activity; it was applied daily to the fresh TMR and stored at 4 degrees C for at least 12 h before feeding. Degradability of OM, NDF, ADF, and cellulose was decreased (P < 0.05) by low pH. Hemicellulose and protein degradation were not affected by pH. Enzyme addition increased (P < 0.01) NDF degradability (by 43% and 25% at high and low pH, respectively), largely as a result of an increase in hemicellulose degradation (by 79% and 51% at high and low pH, respectively). This improvement was supported by an increase (P < 0.05) in the xylanase and cellulase activities in the liquid phase of the fermenter contents. Total VFA were decreased (P < 0.05) by low pH, but were not affected by enzyme addition. Total bacterial numbers were increased (P < 0.03) at low pH and tended (P < 0.13) to increase with enzyme addition. Cellulolytic bacteria in effluent fluid were decreased (P < 0.02) at low pH but were unaffected by enzyme addition. Despite a large increase (P < 0.001) in protease activity, protein degradation was only numerically increased by enzyme addition. Microbial protein synthesis

  3. Evolutionary growth process of highly conserved sequences in vertebrate genomes.

    PubMed

    Ishibashi, Minaka; Noda, Akiko Ogura; Sakate, Ryuichi; Imanishi, Tadashi

    2012-08-01

    Genome sequence comparison between evolutionarily distant species revealed ultraconserved elements (UCEs) among mammals under strong purifying selection. Most of them were also conserved among vertebrates. Because they tend to be located in the flanking regions of developmental genes, they would have fundamental roles in creating vertebrate body plans. However, the evolutionary origin and selection mechanism of these UCEs remain unclear. Here we report that UCEs arose in primitive vertebrates, and gradually grew in vertebrate evolution. We searched for UCEs in two teleost fishes, Tetraodon nigroviridis and Oryzias latipes, and found 554 UCEs with 100% identity over 100 bps. Comparison of teleost and mammalian UCEs revealed 43 pairs of common, jawed-vertebrate UCEs (jUCE) with high sequence identities, ranging from 83.1% to 99.2%. Ten of them retain lower similarities to the Petromyzon marinus genome, and the substitution rates of four non-exonic jUCEs were reduced after the teleost-mammal divergence, suggesting that robust conservation had been acquired in the jawed vertebrate lineage. Our results indicate that prototypical UCEs originated before the divergence of jawed and jawless vertebrates and have been frozen as perfect conserved sequences in the jawed vertebrate lineage. In addition, our comparative sequence analyses of UCEs and neighboring regions resulted in a discovery of lineage-specific conserved sequences. They were added progressively to prototypical UCEs, suggesting step-wise acquisition of novel regulatory roles. Our results indicate that conserved non-coding elements (CNEs) consist of blocks with distinct evolutionary history, each having been frozen since different evolutionary era along the vertebrate lineage. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. Recent Advances in High-Growth Rate Single-Crystal CVD Diamond

    SciTech Connect

    Liang, Q.; Yan, C; Meng, Y; Lai, J; Krasnicki, S; Mao, H; Hemley, R

    2009-01-01

    There have been important advances in microwave plasma chemical vapor deposition (MPCVD) of large single-crystal CVD diamond at high growth rates and applications of this diamond. The types of gas chemistry and growth conditions, including microwave power, pressure, and substrate surface temperatures, have been varied to optimize diamond quality and growth rates. The diamond has been characterized by a variety of spectroscopic and diffraction techniques. We have grown single-crystal CVD diamond over ten carats and above 1 cm in thickness at growth rates of 50-100 {micro}m/h. Colorless and near colorless single crystals up to two carats have been produced by further optimizing the process. The nominal Vickers fracture toughness of this high-growth rate diamond can be tuned to exceed 20 MPa m{sup 1/2} in comparison to 5-10 MPa m{sup 1/2} for conventional natural and CVD diamond. Post-growth high-pressure/high-temperature (HPHT) and low-pressure/high-temperature (LPHT) annealing have been carried out to alter the optical, mechanical, and electronic properties. Most recently, single-crystal CVD diamond has been successfully annealed by LPHT methods without graphitization up to 2200 C and < 300 Torr for periods of time ranging from a fraction of minute to a few hours. Significant changes observed in UV, visible, infrared, and photoluminescence spectra are attributed to changes in various vacancy centers and extended defects.

  5. High-Ti, bright-CL rims in volcanic quartz: a result of very rapid growth

    NASA Astrophysics Data System (ADS)

    Pamukcu, Ayla S.; Ghiorso, Mark S.; Gualda, Guilherme A. R.

    2016-12-01

    Volcanic quartz commonly contains Ti-enriched zones and CO2-enriched melt inclusions, and crystallization temperatures and pressures derived from Ti-in-quartz geothermobarometry and H2O-CO2 glass geobarometry applied to these compositions are typically high. Consequently, these features are generally interpreted to represent high temperatures and/or pressures. Yet, growth rate estimates from some high-Ti/bright-CL quartz rims suggest they grew at rates orders of magnitude faster than did cores and interiors of the crystals. This observation is notable in light of studies that suggest that fast crystal growth rates can produce a boundary layer in the melt surrounding a growing crystal that is enriched in components that diffuse comparatively slowly in the melt. In these circumstances, the composition of zones or melt inclusions formed from such a boundary layer melt will not accurately represent that of the far-field melt, and temperatures and pressures estimated from these compositions will be anomalous. We use a numerical model based on the coupled growth-diffusion equation of Lasaga (1982) to assess the effect of growth rate on the production of high-Ti/bright-CL zones and high-CO2 melt inclusions in quartz in rhyolitic melts. Simulations span a wide range of growth rates (10-7 to 10-13 m/s) and timescales (1 minute-1 year), and results suggest that quartz growth at 10-10 m/s or faster can produce a boundary layer enriched in these components. This suggests that appropriate application of Ti-in-quartz and H2O-CO2 glass geothermobarometry is contingent upon the verification that the compositions used are not those of boundary layer melts. Applying our model to the Bishop Tuff, which contains quartz displaying high-Ti/bright-CL rims and high-CO2 rim-hosted melt inclusions, we find that growth rates of 10-7 to 10-9 m/s can produce the observed enrichments in these components over the timescales estimated for the growth of the rims (days-weeks); these growth rates

  6. The Maintaining Factors of Social Anxiety: A Three-Group Comparison of a Clinical Sample with Highly Socially Anxious Students and Non-Anxious Students.

    PubMed

    Skocic, Sonja; Jackson, Henry; Hulbert, Carol; Faber, Christina

    2016-07-01

    Clark and Wells' (1995) cognitive model of social anxiety (CWM) explains the maintenance of social anxiety and has been used as a guide for treatment of Social Anxiety Disorder (SAD). Few studies have examined the components of the model together across different samples. This study had two distinct aims: to test the components of CWM and to examine how the variables of CWM may differ between clinical and non-clinical samples with varying levels of social anxiety. Hypothesized relationships between three groups (i.e. a clinical sample of individuals diagnosed with SAD (ClinS), n = 40; socially anxious students (HSA), n = 40; and, non-anxious students (LSA), n = 40) were investigated. Four out of five CWM variables tested were able to distinguish between highly socially anxious and non-anxious groups after controlling for age and depression. CWM variables are able to distinguish between high and low levels of social anxiety and are uniquely related to social anxiety over depression.

  7. Growth of high aspect ratio ZnO nanorods by solution process: Effect of polyethyleneimine

    SciTech Connect

    Choi, Han-Seok; Vaseem, Mohammad; Kim, Sang Gon; Im, Yeon-Ho; Hahn, Yoon-Bong

    2012-05-15

    High aspect ratio ZnO nanorods were grown vertically on ZnO seed layer deposited silicon, glass and polyimide substrates by a solution process at low-temperature using zinc nitrate hexahydrate and hexamethylenetetramine. We studied the effect of polyethlyeneimine (PEI) on the growth of ZnO nanorods. It was found that PEI has a prominent effect on controlling the aspect ratio of ZnO nanorods in solution. The morphological and photoluminescence properties of the ZnO nanorods were also examined with varying the growth temperature (60-90 Degree-Sign C). - Graphical abstract: With addition of polyehyleneimine (PEI) high aspect-ratio ZnO nanorods were grown. It is believed that during ZnO nanorods growth, protonized form of linear PEI molecules inhibits the lateral growth by being adsorbed on non-polar lateral planes. Thus the vertical growth is favored. Highlights: Black-Right-Pointing-Pointer A controlled growth of high aspect ratio ZnO nanorods on different substrates. Black-Right-Pointing-Pointer A prominent effect of polyethlyeneimine (PEI) on controlling the aspect ratio of ZnO nanorods in solution. Black-Right-Pointing-Pointer Precursor concentration and growth temperature effect for various aspect ratio ZnO nanorods.

  8. Near-equilibrium growth of thick, high quality beta-SiC by sublimation

    NASA Technical Reports Server (NTRS)

    Shields, Virgil B.; Fekade, Konjit; Spencer, Michael G.

    1993-01-01

    A close spaced near-equilibrium growth technique was used to produce thick, high quality epitaxial layers of beta-silicon carbide. The process utilized a sublimation method to grow morphologically smooth layers. The beta silicon carbide growth layers varied from about 200 to 750 microns in thickness. Chemical vapor deposition grown, 2-10 microns, beta silicon carbide films were used as seeds at 1860 and 1910 C growth temperatures. The respective average growth rates were 20 and 30 microns per hour. The layers are p-type with a 3.1 x 10 exp 17/cu cm carrier concentration. Electrical measurements indicate considerable improvement in the breakdown voltage of Schottky barriers on growth samples. Breakdown values ranged from 25 to 60 V. These measurements represent the highest values reported for 3C-SiC.

  9. High-dose electron beam sterilization of soft-tissue grafts maintains significantly improved biomechanical properties compared to standard gamma treatment.

    PubMed

    Hoburg, A; Keshlaf, S; Schmidt, T; Smith, M; Gohs, U; Perka, C; Pruss, A; Scheffler, S

    2015-06-01

    Allografts have gained increasing popularity in anterior cruciate ligament (ACL) reconstruction. However, one of the major concerns regarding allografts is the possibility of disease transmission. Electron beam (Ebeam) and Gamma radiation have been proven to be successful in sterilization of medical products. In soft tissue sterilization high dosages of gamma irradiation have been shown to be detrimental to biomechanical properties of grafts. Therefore, it was the objective of this study to compare the biomechanical properties of human bone-patellar tendon-bone (BPTB) grafts after ebeam with standard gamma irradiation at medium (25 kGy) and high doses (34 kGy). We hypothesized that the biomechanical properties of Ebeam irradiated grafts would be superior to gamma irradiated grafts. Paired 10 mm-wide human BPTB grafts were harvested from 20 donors split into four groups following irradiation with either gamma or Ebeam (each n = 10): (A) Ebeam 25 kGy, (B) Gamma 25 kGy, (C) Ebeam 34 kGy (D) Gamma 34 kGy and ten non-irradiated BPTB grafts were used as controls. All grafts underwent biomechanical testing which included preconditioning (ten cycles, 0-20 N); cyclic loading (200 cycles, 20-200 N) and a load-to-failure (LTF) test. Stiffness of non-irradiated controls (199.6 ± 59.1 N/mm) and Ebeam sterilized grafts did not significantly differ (152.0 ± 37.0 N/mm; 192.8 ± 58.0 N/mm), while Gamma-irradiated grafts had significantly lower stiffness than controls at both irradiation dosages (25 kGy: 126.1 ± 45.4 N/mm; 34 kGy: 170.6 ± 58.2 N/mm) (p < 0.05). Failure loads at 25 kGy were significantly lower in the gamma group (1,009 ± 400 N), while the failure load was significantly lower in both study groups at high dose irradiation with 34 kGy (Ebeam: 1,139 ± 445 N, Gamma: 1,073 ± 617 N) compared to controls (1,741 ± 304 N) (p < 0.05). Creep was significantly larger in the gamma irradiated groups (25 kGy: 0.96 ± 1.34 mm; 34 kGy: 1.06 ± 0.58 mm) than in the Ebeam (25 k

  10. Drought-induced weakening of growth-temperature associations in high-elevation Iberian pines

    NASA Astrophysics Data System (ADS)

    Diego Galván, J.; Büntgen, Ulf; Ginzler, Christian; Grudd, Håkan; Gutiérrez, Emilia; Labuhn, Inga; Julio Camarero, J.

    2015-01-01

    The growth/climate relationship of theoretically temperature-controlled high-elevation forests has been demonstrated to weaken over recent decades. This is likely due to new tree growth limiting factors, such as an increasing drought risk for ecosystem functioning and productivity across the Mediterranean Basin. In addition, declining tree growth sensitivity to spring temperature may emerge in response to increasing drought stress. Here, we evaluate these ideas by assessing the growth/climate sensitivity of 1500 tree-ring width (TRW) and 102 maximum density (MXD) measurement series from 711 and 74 Pinus uncinata trees, respectively, sampled at 28 high-elevation forest sites across the Pyrenees and two relict populations of the Iberian System. Different dendroclimatological standardization and split period approaches were used to assess the high- to low-frequency behavior of 20th century tree growth in response to temperature means, precipitation totals and drought indices. Long-term variations in TRW track summer temperatures until about 1970 but diverge afterwards, whereas MXD captures the recent temperature increase in the low-frequency domain fairly well. On the other hand summer drought has increasingly driven TRW along the 20th century. Our results suggest fading temperature sensitivity of Iberian high-elevation P. uncinata forest growth, and reveal the importance of summer drought that is becoming the emergent limiting factor of tree ring width formation in many parts of the Mediterranean Basin.

  11. Harnessing High Density Lipoproteins to Block Transforming Growth Factor Beta and to Inhibit the Growth of Liver Tumor Metastases

    PubMed Central

    Medina-Echeverz, José; Fioravanti, Jessica; Díaz-Valdés, Nancy; Frank, Kathrin; Aranda, Fernando; Gomar, Celia; Ardaiz, Nuria; Dotor, Javier; Umansky, Viktor; Prieto, Jesús; Berraondo, Pedro

    2014-01-01

    Transforming growth factor β (TGF-β) is a powerful promoter of cancer progression and a key target for antitumor therapy. As cancer cells exhibit active cholesterol metabolism, high density lipoproteins (HDLs) appear as an attractive delivery system for anticancer TGFβ-inhibitory molecules. We constructed a plasmid encoding a potent TGF-β-blocking peptide (P144) linked to apolipoprotein A-I (ApoA-I) through a flexible linker (pApoLinkerP144). The ApoLinkerP144 sequence was then incorporated into a hepatotropic adeno-associated vector (AAVApoLinkerP144). The aim was to induce hepatocytes to produce HDLs containing a modified ApoA-I capable of blocking TGF-β. We observed that transduction of the murine liver with pApoLinkerP144 led to the appearance of a fraction of circulating HDL containing the fusion protein. These HDLs were able to attenuate TGF-β signaling in the liver and to enhance IL-12 -mediated IFN-γ production. Treatment of liver metastasis of MC38 colorectal cancer with AAVApoLinkerP144 resulted in a significant reduction of tumor growth and enhanced expression of IFN-γ and GM-CSF in cancerous tissue. ApoLinkerP144 also delayed MC38 liver metastasis in Rag2−/−IL2rγ−/− immunodeficient mice. This effect was associated with downregulation of TGF-β target genes essential for metastatic niche conditioning. Finally, in a subset of ret transgenic mice, a model of aggressive spontaneous metastatic melanoma, AAVApoLinkerP144 delayed tumor growth in association with increased CD8+ T cell numbers in regional lymph nodes. In conclusion, modification of HDLs to transport TGF-β-blocking molecules is a novel and promising approach to inhibit the growth of liver metastases by immunological and non-immunological mechanisms. PMID:24797128

  12. SIRT3 Is Crucial for Maintaining Skeletal Muscle Insulin Action and Protects Against Severe Insulin Resistance in High-Fat–Fed Mice

    PubMed Central

    Williams, Ashley S.; Williams, Ian M.; Yang, Karen K.; Bracy, Deanna P.; Goelzer, Mickael; James, Freyja D.; Gius, David; Wasserman, David H.

    2015-01-01

    Protein hyperacetylation is associated with glucose intolerance and insulin resistance, suggesting that the enzymes regulating the acetylome play a role in this pathological process. Sirtuin 3 (SIRT3), the primary mitochondrial deacetylase, has been linked to energy homeostasis. Thus, it is hypothesized that the dysregulation of the mitochondrial acetylation state, via genetic deletion of SIRT3, will amplify the deleterious effects of a high-fat diet (HFD). Hyperinsulinemic-euglycemic clamp experiments show, for the first time, that mice lacking SIRT3 exhibit increased insulin resistance due to defects in skeletal muscle glucose uptake. Permeabilized muscle fibers from HFD-fed SIRT3 knockout (KO) mice showed that tricarboxylic acid cycle substrate–based respiration is decreased while fatty acid–based respiration is increased, reflecting a fuel switch from glucose to fatty acids. Consistent with reduced muscle glucose uptake, hexokinase II (HKII) binding to the mitochondria is decreased in muscle from HFD-fed SIRT3 KO mice, suggesting decreased HKII activity. These results show that the absence of SIRT3 in HFD-fed mice causes profound impairments in insulin-stimulated muscle glucose uptake, creating an increased reliance on fatty acids. Insulin action was not impaired in the lean SIRT3 KO mice. This suggests that SIRT3 protects against dietary insulin resistance by facilitating glucose disposal and mitochondrial function. PMID:25948682

  13. Human naïve regulatory T-cells feature high steady-state turnover and are maintained by IL-7.

    PubMed

    Silva, Susana L; Albuquerque, Adriana S; Serra-Caetano, Ana; Foxall, Russell B; Pires, Ana R; Matoso, Paula; Fernandes, Susana M; Ferreira, João; Cheynier, Rémi; Victorino, Rui M M; Caramalho, Iris; Barata, João T; Sousa, Ana E

    2016-03-15

    Naïve FoxP3-expressing regulatory T-cells (Tregs) are essential to control immune responses via continuous replenishment of the activated-Treg pool with thymus-committed suppressor cells. The mechanisms underlying naïve-Treg maintenance throughout life in face of the age-associated thymic involution remain unclear. We found that in adults thymectomized early in infancy the naïve-Treg pool is remarkably well preserved, in contrast to conventional naïve CD4 T-cells. Naïve-Tregs featured high levels of cycling and pro-survival markers, even in healthy individuals, and contrasted with other circulating naïve/memory CD4 T-cell subsets in terms of their strong γc-cytokine-dependent signaling, particularly in response to IL-7. Accordingly, ex-vivo stimulation of naïve-Tregs with IL-7 induced robust cytokine-dependent signaling, Bcl-2 expression, and phosphatidylinositol 3-kinase (PI3K)-dependent proliferation, whilst preserving naïve phenotype and suppressive capacity. Altogether, our data strongly implicate IL-7 in the thymus-independent long-term survival of functional naïve-Tregs, and highlight the potential of targeting the IL-7 pathway to modulate Tregs in different clinical settings.

  14. IL-12 and type I interferon prolong the division of activated CD8 T cells by maintaining high-affinity IL-2 signaling in vivo

    PubMed Central

    Starbeck-Miller, Gabriel R.; Xue, Hai-Hui

    2014-01-01

    TCR ligation and co-stimulation induce cellular division; however, optimal accumulation of effector CD8 T cells requires direct inflammatory signaling by signal 3 cytokines, such as IL-12 or type I IFNs. Although in vitro studies suggest that IL-12/type I IFN may enhance T cell survival or early proliferation, the mechanisms underlying optimal accumulation of CD8 T cells in vivo are unknown. In particular, it is unclear if disparate signal 3 cytokines optimize effector CD8 T cell accumulation by the same mechanism and how these inflammatory cytokines, which are transiently produced early after infection, affect T cell accumulation many days later at the peak of the immune response. Here, we show that transient exposure of CD8 T cells to IL-12 or type I IFN does not promote survival or confer an early proliferative advantage in vivo, but rather sustains surface expression of CD25, the high-affinity IL-2 receptor. This prolongs division of CD8 T cells in response to basal IL-2, through activation of the PI3K pathway and expression of FoxM1, a positive regulator of cell cycle progression genes. Thus, signal 3 cytokines use a common pathway to optimize effector CD8 T cell accumulation through a temporally orchestrated sequence of cytokine signals that sustain division rather than survival. PMID:24367005

  15. SIRT3 Is Crucial for Maintaining Skeletal Muscle Insulin Action and Protects Against Severe Insulin Resistance in High-Fat-Fed Mice.

    PubMed

    Lantier, Louise; Williams, Ashley S; Williams, Ian M; Yang, Karen K; Bracy, Deanna P; Goelzer, Mickael; James, Freyja D; Gius, David; Wasserman, David H

    2015-09-01

    Protein hyperacetylation is associated with glucose intolerance and insulin resistance, suggesting that the enzymes regulating the acetylome play a role in this pathological process. Sirtuin 3 (SIRT3), the primary mitochondrial deacetylase, has been linked to energy homeostasis. Thus, it is hypothesized that the dysregulation of the mitochondrial acetylation state, via genetic deletion of SIRT3, will amplify the deleterious effects of a high-fat diet (HFD). Hyperinsulinemic-euglycemic clamp experiments show, for the first time, that mice lacking SIRT3 exhibit increased insulin resistance due to defects in skeletal muscle glucose uptake. Permeabilized muscle fibers from HFD-fed SIRT3 knockout (KO) mice showed that tricarboxylic acid cycle substrate-based respiration is decreased while fatty acid-based respiration is increased, reflecting a fuel switch from glucose to fatty acids. Consistent with reduced muscle glucose uptake, hexokinase II (HKII) binding to the mitochondria is decreased in muscle from HFD-fed SIRT3 KO mice, suggesting decreased HKII activity. These results show that the absence of SIRT3 in HFD-fed mice causes profound impairments in insulin-stimulated muscle glucose uptake, creating an increased reliance on fatty acids. Insulin action was not impaired in the lean SIRT3 KO mice. This suggests that SIRT3 protects against dietary insulin resistance by facilitating glucose disposal and mitochondrial function. © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

  16. The role of apelin in central cardiovascular regulation in rats with post-infarct heart failure maintained on a normal fat or high fat diet.

    PubMed

    Czarzasta, Katarzyna; Cudnoch-Jedrzejewska, Agnieszka; Szczepanska-Sadowska, Ewa; Fus, Lukasz; Puchalska, Liana; Gondek, Agata; Dobruch, Jakub; Gomolka, Ryszard; Wrzesien, Robert; Zera, Tymoteusz; Gornicka, Barbara; Kuch, Marek

    2016-10-01

    Based on the available literature, it can be assumed that in cases of post-infarct heart failure (HF) and obesity, a significant change in the central regulation of the cardiovascular system takes place with, among others, the involvement of the apelinergic system. The main objective of the present study was to clarify the role of apelin-13 in the central regulation of the cardiovascular system in Sprague Dawley rats with HF or sham operated (SO) and fed on a normal fat (NFD) or a high fat diet (HFD). The study was divided into two parts: Part I, hemodynamic studies; and Part II, biochemical and molecular studies. The animals were subjected to the following research procedures. Part I and II: feeding NFD or HFD; experimental induction of HF or SO; Part I: intracerebroventricular (ICV) infusion of the examined substances, monitoring of mean arterial blood pressure (MABP) and heart rate (HR); Part II: venous blood and tissue samples collected. ICV infusion of apelin-13 caused significantly higher changes in ΔMABP in the SO NFD group. No changes were noted in ΔHR in any of the studied groups. Apelin and apelin receptor (APJ) mRNA expression in the brain and adipose tissues was higher in the HF rats. HFD causes significant increase in expression of apelin and APJ mRNA in the left ventricle. In conclusion, HF and HFD appear to play an important role in modifying the activity of the central apelinergic system and significant changes in mRNA expression of apelin and APJ receptor. © 2016 John Wiley & Sons Australia, Ltd.

  17. Homoepitaxial growth of metal halide crystals investigated by reflection high-energy electron diffraction

    DOE PAGES

    Chen, Pei; Kuttipillai, Padmanaban S.; Wang, Lili; ...

    2017-01-10

    Here, we report the homoepitaxial growth of a metal halide on single crystals investigated with in situ reflection high-energy electron diffraction (RHEED) and ex situ atomic force microscopy (AFM). Epitaxial growth of NaCl on NaCl (001) is explored as a function of temperature and growth rate which provides the first detailed report of RHEED oscillations for metal halide growth. Layer-by-layer growth is observed at room temperature accompanied by clear RHEED oscillations while the growth mode transitions to an island (3D) mode at low temperature. At higher temperatures (>100 °C), RHEED oscillations and AFM data indicate a transition to a step-flowmore » growth mode. To show the importance of such metal halide growth, green organic light-emitting diodes (OLEDs) are demonstrated using a doped NaCl film with a phosphorescent emitter as the emissive layer. This study demonstrates the ability to perform in situ and non-destructive RHEED monitoring even on insulating substrates and could enable doped single crystals and crystalline substrates for a range of optoelectronic applications.« less

  18. Homoepitaxial Growth of Metal Halide Crystals Investigated by Reflection High-Energy Electron Diffraction

    NASA Astrophysics Data System (ADS)

    Chen, Pei; Kuttipillai, Padmanaban S.; Wang, Lili; Lunt, Richard R.

    2017-01-01

    We report the homoepitaxial growth of a metal halide on single crystals investigated with in situ reflection high-energy electron diffraction (RHEED) and ex situ atomic force microscopy (AFM). Epitaxial growth of NaCl on NaCl (001) is explored as a function of temperature and growth rate which provides the first detailed report of RHEED oscillations for metal halide growth. Layer-by-layer growth is observed at room temperature accompanied by clear RHEED oscillations while the growth mode transitions to an island (3D) mode at low temperature. At higher temperatures (>100 °C), RHEED oscillations and AFM data indicate a transition to a step-flow growth mode. To show the importance of such metal halide growth, green organic light-emitting diodes (OLEDs) are demonstrated using a doped NaCl film with a phosphorescent emitter as the emissive layer. This study demonstrates the ability to perform in situ and non-destructive RHEED monitoring even on insulating substrates and could enable doped single crystals and crystalline substrates for a range of optoelectronic applications.

  19. Homoepitaxial Growth of Metal Halide Crystals Investigated by Reflection High-Energy Electron Diffraction

    PubMed Central

    Chen, Pei; Kuttipillai, Padmanaban S.; Wang, Lili; Lunt, Richard R.

    2017-01-01

    We report the homoepitaxial growth of a metal halide on single crystals investigated with in situ reflection high-energy electron diffraction (RHEED) and ex situ atomic force microscopy (AFM). Epitaxial growth of NaCl on NaCl (001) is explored as a function of temperature and growth rate which provides the first detailed report of RHEED oscillations for metal halide growth. Layer-by-layer growth is observed at room temperature accompanied by clear RHEED oscillations while the growth mode transitions to an island (3D) mode at low temperature. At higher temperatures (>100 °C), RHEED oscillations and AFM data indicate a transition to a step-flow growth mode. To show the importance of such metal halide growth, green organic light-emitting diodes (OLEDs) are demonstrated using a doped NaCl film with a phosphorescent emitter as the emissive layer. This study demonstrates the ability to perform in situ and non-destructive RHEED monitoring even on insulating substrates and could enable doped single crystals and crystalline substrates for a range of optoelectronic applications. PMID:28071732

  20. Big-data reflection high energy electron diffraction analysis for understanding epitaxial film growth processes.

    PubMed

    Vasudevan, Rama K; Tselev, Alexander; Baddorf, Arthur P; Kalinin, Sergei V

    2014-10-28

    Reflection high energy electron diffraction (RHEED) has by now become a standard tool for in situ monitoring of film growth by pulsed laser deposition and molecular beam epitaxy. Yet despite the widespread adoption and wealth of information in RHEED images, most applications are limited to observing intensity oscillations of the specular spot, and much additional information on growth is discarded. With ease of data acquisition and increased computation speeds, statistical methods to rapidly mine the data set are now feasible. Here, we develop such an approach to the analysis of the fundamental growth processes through multivariate statistical analysis of a RHEED image sequence. This approach is illustrated for growth of La(x)Ca(1-x)MnO(3) films grown on etched (001) SrTiO(3) substrates, but is universal. The multivariate methods including principal component analysis and k-means clustering provide insight into the relevant behaviors, the timing and nature of a disordered to ordered growth change, and highlight statistically significant patterns. Fourier analysis yields the harmonic components of the signal and allows separation of the relevant components and baselines, isolating the asymmetric nature of the step density function and the transmission spots from the imperfect layer-by-layer (LBL) growth. These studies show the promise of big data approaches to obtaining more insight into film properties during and after epitaxial film growth. Furthermore, these studies open the pathway to use forward prediction methods to potentially allow significantly more control over growth process and hence final film quality.

  1. [Over-compensatory growth of Microcystis aeruginosa after high temperature stress].

    PubMed

    Qin, Hong-jie; Li, Dun-hai

    2010-07-01

    Two groups of Microcystis aeruginosa FACHB 905 cultures, 40 degrees C and 25 degrees c cultures were set in present study. Both of them were cultured for 5 and 10 days before transferred to fresh medium in same cell densities and then cultured under the same conditions at 25 degrees C. The algae which were cultured under 25 degrees C for all the time were set as the control. The growth, chlorophyll a concentration, Fv/Fm, net photosynthetic rate and respiration rate were determined after re-inoculation. The result showed that the high temperature treated groups have lower specific growth rate and lower Fv/Fm than those of control groups (p < 0.01). However, in the middle-later stage of recovery growth, the specific growth rate of 40 degrees C for 5 days group was 0.362, and it was significantly higher than that of control groups of 0.301 (p < 0.05), while the specific growth rate of 40 degrees c for 10 days group was 0.358, and there was no significant difference with control. 40 degrees C for 5 days group showed over-compensatory growth while 40 degrees C for 10 days group showed exact-compensatory growth. It implies that the over-compensatory growth characteristics of Microcysis aeruginosa is an endogenous biological factor that contributing the outbreak of blooms.

  2. Natural Genetic Variation for Growth and Development Revealed by High-Throughput Phenotyping in Arabidopsis thaliana

    PubMed Central

    Zhang, Xu; Hause, Ronald J.; Borevitz, Justin O.

    2012-01-01

    Leaf growth and development determines a plant’s capacity for photosynthesis and carbon fixation. These morphological traits are the integration of genetic and environmental factors through time. Yet fine dissection of the developmental genetic basis of leaf expansion throughout a growing season is difficult, due to the complexity of the trait and the need for real time measurement. In this study, we developed a time-lapse image analysis approach, which traces leaf expansion under seasonal light variation. Three growth traits, rosette leaf area, circular area, and their ratio as compactness, were measured and normalized on a linear timescale to control for developmental heterogeneity. We found high heritability for all growth traits that changed over time. Our study highlights a cost-effective, high-throughput phenotyping approach that facilitates the dissection of genetic basis of plant shoot growth and development under dynamic environmental conditions. PMID:22384379

  3. High speed growth of SrI2 scintillator crystals by the EFG process

    NASA Astrophysics Data System (ADS)

    Calvert, G.; Guguschev, C.; Burger, A.; Groza, M.; Derby, J. J.; Feigelson, R. S.

    2016-12-01

    Strontium iodide (SrI2), an important new scintillator crystal having a high light yield and excellent energy resolution, was grown for the first time by the edge-defined film-fed (EFG) growth method. Using high purity starting materials and floating dies made of graphite, fused quartz or AlN, large cylindrical, planar or square cross-section single crystals (12-15 mm across and >7 cm long) were produced at growth rates up to 15 mm/h, significantly faster than the current Bridgman growth technology. Details on the equipment used to grow this deliquescent material and on its growth behavior are given along with some discussion of crystalline quality.

  4. Natural Genetic Variation for Growth and Development Revealed by High-Throughput Phenotyping in Arabidopsis thaliana.

    PubMed

    Zhang, Xu; Hause, Ronald J; Borevitz, Justin O

    2012-01-01

    Leaf growth and development determines a plant's capacity for photosynthesis and carbon fixation. These morphological traits are the integration of genetic and environmental factors through time. Yet fine dissection of the developmental genetic basis of leaf expansion throughout a growing season is difficult, due to the complexity of the trait and the need for real time measurement. In this study, we developed a time-lapse image analysis approach, which traces leaf expansion under seasonal light variation. Three growth traits, rosette leaf area, circular area, and their ratio as compactness, were measured and normalized on a linear timescale to control for developmental heterogeneity. We found high heritability for all growth traits that changed over time. Our study highlights a cost-effective, high-throughput phenotyping approach that facilitates the dissection of genetic basis of plant shoot growth and development under dynamic environmental conditions.

  5. Fatigue Crack Growth Behavior of Metastable Austenitic Stainless Steel in Cryogenic High Magnetic Field Environments

    NASA Astrophysics Data System (ADS)

    Shindo, Yasuhide; Takeda, Tomo; Suzuki, Masato; Narita, Fumio

    2009-08-01

    This article studies the fatigue crack growth in a metastable austenitic stainless steel in cryogenic high magnetic field environments. Fatigue crack growth tests were performed with the compact tension (CT) specimens at liquid helium temperature (4 K) in magnetic fields of 0 and 6 T, and the crack growth rate data were expressed in terms of the J-integral range during fatigue loading. The J-integral range values were evaluated using an elastic-plastic finite element analysis. The measurement of martensite phase in the test specimens and the fractographic examination were also carried out. The high magnetic field effect on the fatigue crack growth rate properties at 4 K is discussed in detail.

  6. A highly conserved gene island of three genes on chromosome 3B of hexaploid wheat: diverse gene function and genomic structure maintained in a tightly linked block

    PubMed Central

    2010-01-01

    Background The complexity of the wheat genome has resulted from waves of retrotransposable element insertions. Gene deletions and disruptions generated by the fast replacement of repetitive elements in wheat have resulted in disruption of colinearity at a micro (sub-megabase) level among the cereals. In view of genomic changes that are possible within a given time span, conservation of genes between species tends to imply an important functional or regional constraint that does not permit a change in genomic structure. The ctg1034 contig completed in this paper was initially studied because it was assigned to the Sr2 resistance locus region, but detailed mapping studies subsequently assigned it to the long arm of 3B and revealed its unusual features. Results BAC shotgun sequencing of the hexaploid wheat (Triticum aestivum cv. Chinese Spring) genome has been used to assemble a group of 15 wheat BACs from the chromosome 3B physical map FPC contig ctg1034 into a 783,553 bp genomic sequence. This ctg1034 sequence was annotated for biological features such as genes and transposable elements. A three-gene island was identified among >80% repetitive DNA sequence. Using bioinformatics analysis there were no observable similarity in their gene functions. The ctg1034 gene island also displayed complete conservation of gene order and orientation with syntenic gene islands found in publicly available genome sequences of Brachypodium distachyon, Oryza sativa, Sorghum bicolor and Zea mays, even though the intergenic space and introns were divergent. Conclusion We propose that ctg1034 is located within the heterochromatic C-band region of deletion bin 3BL7 based on the identification of heterochromatic tandem repeats and presence of significant matches to chromodomain-containing gypsy LTR retrotransposable elements. We also speculate that this location, among other highly repetitive sequences, may account for the relative stability in gene order and orientation within the gene

  7. Multidrug- and Extensively Drug-Resistant Uropathogenic Escherichia coli Clinical Strains: Phylogenetic Groups Widely Associated with Integrons Maintain High Genetic Diversity

    PubMed Central

    Ochoa, Sara A.; Cruz-Córdova, Ariadnna; Luna-Pineda, Victor M.; Reyes-Grajeda, Juan P.; Cázares-Domínguez, Vicenta; Escalona, Gerardo; Sepúlveda-González, Ma. Eugenia; López-Montiel, Fernanda; Arellano-Galindo, José; López-Martínez, Briceida; Parra-Ortega, Israel; Giono-Cerezo, Silvia; Hernández-Castro, Rigoberto; de la Rosa-Zamboni, Daniela; Xicohtencatl-Cortes, Juan

    2016-01-01

    In recent years, an increase of uropathogenic Escherichia coli (UPEC) strains with Multidrug-resistant (MDR) and Extensively Drug-resistant (XDR) profiles that complicate therapy for urinary tract infections (UTIs) has been observed and has directly impacted costs and extended hospital stays. The aim of this study was to determine MDR- and XDR-UPEC clinical strains, their virulence genes, their phylogenetic groups and to ascertain their relationship with integrons and genetic diversity. From a collection of 500 UPEC strains, 103 were selected with MDR and XDR characteristics. MDR-UPEC strains were mainly associated with phylogenetic groups D (54.87%) and B2 (39.02%) with a high percentage (≥70%) of several fimbrial genes (ecpA, fimH, csgA, and papGII), an iron uptake gene (chuA), and a toxin gene (hlyA). In addition, a moderate frequency (40–70%) of other genes (iutD, tosA, and bcsA) was observed. XDR-UPEC strains were predominantly associated with phylogenetic groups B2 (47.61%) and D (42.85%), which grouped with ≥80 virulence genes, including ecpA, fimH, csgA, papGII, iutD, and chuA. A moderate frequency (40–70%) of the tosA and hlyA genes was observed. The class 1 and 2 integrons that were identified in the MDR- and XDR-UPEC strains were associated with phylogenetic groups D, B2, and A, while the XDR-UPEC strains that were associated with phylogenetic groups B2, D, and A showed an extended-spectrum beta-lactamase (ESBL) phenotype. The modifying enzymes (aadA1, aadB, aacC, ant1, dfrA1, dfrA17, and aadA4) that were identified in the variable region of class 1 and 2 integrons from the MDR strains showed resistance to gentamycin (56.25 and 66.66%, respectively) and trimethoprim-sulfamethoxazole (84.61 and 66.66%, respectively). The MDR- and XDR-UPEC strains were distributed into seven clusters and were closely related to phylogenic groups B2 and D. The diversity analysis by PFGE showed 42.68% of clones of MDR-UPEC and no clonal association in the XDR

  8. Multidrug- and Extensively Drug-Resistant Uropathogenic Escherichia coli Clinical Strains: Phylogenetic Groups Widely Associated with Integrons Maintain High Genetic Diversity.

    PubMed

    Ochoa, Sara A; Cruz-Córdova, Ariadnna; Luna-Pineda, Victor M; Reyes-Grajeda, Juan P; Cázares-Domínguez, Vicenta; Escalona, Gerardo; Sepúlveda-González, Ma Eugenia; López-Montiel, Fernanda; Arellano-Galindo, José; López-Martínez, Briceida; Parra-Ortega, Israel; Giono-Cerezo, Silvia; Hernández-Castro, Rigoberto; de la Rosa-Zamboni, Daniela; Xicohtencatl-Cortes, Juan

    2016-01-01

    In recent years, an increase of uropathogenic Escherichia coli (UPEC) strains with Multidrug-resistant (MDR) and Extensively Drug-resistant (XDR) profiles that complicate therapy for urinary tract infections (UTIs) has been observed and has directly impacted costs and extended hospital stays. The aim of this study was to determine MDR- and XDR-UPEC clinical strains, their virulence genes, their phylogenetic groups and to ascertain their relationship with integrons and genetic diversity. From a collection of 500 UPEC strains, 103 were selected with MDR and XDR characteristics. MDR-UPEC strains were mainly associated with phylogenetic groups D (54.87%) and B2 (39.02%) with a high percentage (≥70%) of several fimbrial genes (ecpA, fimH, csgA, and papGII), an iron uptake gene (chuA), and a toxin gene (hlyA). In addition, a moderate frequency (40-70%) of other genes (iutD, tosA, and bcsA) was observed. XDR-UPEC strains were predominantly associated with phylogenetic groups B2 (47.61%) and D (42.85%), which grouped with ≥80 virulence genes, including ecpA, fimH, csgA, papGII, iutD, and chuA. A moderate frequency (40-70%) of the tosA and hlyA genes was observed. The class 1 and 2 integrons that were identified in the MDR- and XDR-UPEC strains were associated with phylogenetic groups D, B2, and A, while the XDR-UPEC strains that were associated with phylogenetic groups B2, D, and A showed an extended-spectrum beta-lactamase (ESBL) phenotype. The modifying enzymes (aadA1, aadB, aacC, ant1, dfrA1, dfrA17, and aadA4) that were identified in the variable region of class 1 and 2 integrons from the MDR strains showed resistance to gentamycin (56.25 and 66.66%, respectively) and trimethoprim-sulfamethoxazole (84.61 and 66.66%, respectively). The MDR- and XDR-UPEC strains were distributed into seven clusters and were closely related to phylogenic groups B2 and D. The diversity analysis by PFGE showed 42.68% of clones of MDR-UPEC and no clonal association in the XDR

  9. Crack Growth of D6 Steel in Air and High Pressure Oxygen

    NASA Technical Reports Server (NTRS)

    Bixler, W. D.; Engstrom, W. L.

    1971-01-01

    Fracture and subcritical flaw growth characteristics were experimentally deter­mined for electroless nickel plated D6 steel in dry air and high pressure oxygen environments as applicable to the Lunar Module/Environmental Control System (LM/ECS) descent gaseous oxygen (GOX) tank. The material tested included forgings, plate, and actual LM/ECS descent GOX tank material. Parent metal and TIG (tungsten inert gas) welds were tested. Tests indicate that proof testing the tanks at 4000 pounds per square inch or higher will insure safe operation at 3060 pounds per square inch. Although significant flaw growth can occur during proofing, subsequent growth of flaws during normal tank operation is negligible.

  10. Predicting growth of graphene nanostructures using high-fidelity atomistic simulations

    SciTech Connect

    McCarty, Keven F.; Zhou, Xiaowang; Ward, Donald K.; Schultz, Peter A.; Foster, Michael E.; Bartelt, Norman Charles

    2015-09-01

    In this project we developed t he atomistic models needed to predict how graphene grows when carbon is deposited on metal and semiconductor surfaces. We first calculated energies of many carbon configurations using first principles electronic structure calculations and then used these energies to construct an empirical bond order potentials that enable s comprehensive molecular dynamics simulation of growth. We validated our approach by comparing our predictions to experiments of graphene growth on Ir, Cu and Ge. The robustness of ou r understanding of graphene growth will enable high quality graphene to be grown on novel substrates which will expand the number of potential types of graphene electronic devices.

  11. Fast Growth of Highly Ordered TiO2 Nanotube Arrays on Si Substrate under High-Field Anodization

    NASA Astrophysics Data System (ADS)

    Song, Jingnan; Zheng, Maojun; Zhang, Bin; Li, Qiang; Wang, Faze; Ma, Liguo; Li, Yanbo; Zhu, Changqing; Ma, Li; Shen, Wenzhong

    2017-04-01

    Highly ordered TiO2 nanotube arrays (NTAs) on Si substrate possess broad applications due to its high surface-to-volume ratio and novel functionalities, however, there are still some challenges on facile synthesis. Here, we report a simple and cost-effective high-field (90-180 V) anodization method to grow highly ordered TiO2 NTAs on Si substrate, and investigate the effect of anodization time, voltage, and fluoride content on the formation of TiO2 NTAs. The current density-time curves, recorded during anodization processes, can be used to determine the optimum anodization time. It is found that the growth rate of TiO2 NTAs is improved significantly under high field, which is nearly 8 times faster than that under low fields (40-60 V). The length and growth rate of the nanotubes are further increased with the increase of fluoride content in the electrolyte.

  12. Strategies for minimizing emittance growth in high charge CW FEL injectors

    SciTech Connect

    Liu, H.

    1995-12-31

    This paper is concerned with the best strategies for designing low emittance, high charge CW FEL injectors. This issue has become more and more critical as today`s interest in FELs is toward UV wavelength high average power operation. The challenge of obtaining the smallest possible emittance is discussed from both the practical point of view and the beam physics point of view. Various mechanisms responsible for beam emittance growth are addressed in detail. Finally, the design of a high charge injector test stand at CEBAF is chosen to help illustrate the design strategies and emittance growth mechanisms discussed in this paper.

  13. Brief Report: A Growth Mixture Model of Occupational Aspirations of Individuals with High-Incidence Disabilities

    ERIC Educational Resources Information Center

    Lee, In Heok; Rojewski, Jay W.

    2013-01-01

    A previous longitudinal study of the occupational aspirations of individuals with high-incidence disabilities revealed multiple longitudinal patterns for individuals with learning disabilities or emotional-behavioral disorders. Growth mixture modeling was used to determine whether individuals in these two high-incidence disabilities groups (N =…

  14. Brief Report: A Growth Mixture Model of Occupational Aspirations of Individuals with High-Incidence Disabilities

    ERIC Educational Resources Information Center

    Lee, In Heok; Rojewski, Jay W.

    2013-01-01

    A previous longitudinal study of the occupational aspirations of individuals with high-incidence disabilities revealed multiple longitudinal patterns for individuals with learning disabilities or emotional-behavioral disorders. Growth mixture modeling was used to determine whether individuals in these two high-incidence disabilities groups (N =…

  15. Ambient surfactantless synthesis, growth mechanism, and size-dependent electrocatalytic behavior of high-quality, single crystalline palladium nanowires.

    PubMed

    Koenigsmann, Christopher; Santulli, Alexander C; Sutter, Eli; Wong, Stanislaus S

    2011-09-27

    In this report, we utilize the U-tube double diffusion device as a reliable, environmentally friendly method for the size-controlled synthesis of high-quality, single crystalline Pd nanowires. The nanowires grown in 200 and 15 nm polycarbonate template pores maintain diameters of 270 ± 45 nm and 45 ± 9 nm, respectively, and could be isolated either as individual nanowires or as ordered free-standing arrays. The growth mechanism of these nanowires has been extensively explored, and we have carried out characterization of the isolated nanowires, free-standing nanowire arrays, and cross sections of the filled template in order to determine that a unique two-step growth process predominates within the template pores. Moreover, as-prepared submicrometer and nanosized wires were studied by comparison with ultrathin 2 nm Pd nanowires in order to elucidate the size-dependent trend in oxygen reduction reaction (ORR) electrocatalysis. Subsequently, the desired platinum monolayer overcoating was reliably deposited onto the surface of the Pd nanowires by Cu underpotential deposition (UPD) followed by galvanic displacement of the Cu adatoms. The specific and platinum mass activity of the core-shell catalysts was found to increase from 0.40 mA/cm(2) and 1.01 A/mg to 0.74 mA/cm(2) and 1.74 A/mg as the diameter was decreased from the submicrometer size regime to the ultrathin nanometer range.

  16. High Arctic summer warming tracked by increased Cassiope tetragona growth in the world's northernmost polar desert.

    PubMed

    Weijers, Stef; Buchwal, Agata; Blok, Daan; Löffler, Jörg; Elberling, Bo

    2017-11-01

    Rapid climate warming has resulted in shrub expansion, mainly of erect deciduous shrubs in the Low Arctic, but the more extreme, sparsely vegetated, cold and dry High Arctic is generally considered to remain resistant to such shrub expansion in the next decades. Dwarf shrub dendrochronology may reveal climatological causes of past changes in growth, but is hindered at many High Arctic sites by short and fragmented instrumental climate records. Moreover, only few High Arctic shrub chronologies cover the recent decade of substantial warming. This study investigated the climatic causes of growth variability of the evergreen dwarf shrub Cassiope tetragona between 1927 and 2012 in the northernmost polar desert at 83°N in North Greenland. We analysed climate-growth relationships over the period with available instrumental data (1950-2012) between a 102-year-long C. tetragona shoot length chronology and instrumental climate records from the three nearest meteorological stations, gridded climate data, and North Atlantic Oscillation (NAO) and Arctic Oscillation (AO) indices. July extreme maximum temperatures (JulTemx ), as measured at Alert, Canada, June NAO, and previous October AO, together explained 41% of the observed variance in annual C. tetragona growth and likely represent in situ summer temperatures. JulTemx explained 27% and was reconstructed back to 1927. The reconstruction showed relatively high growing season temperatures in the early to mid-twentieth century, as well as warming in recent decades. The rapid growth increase in C. tetragona shrubs in response to recent High Arctic summer warming shows that recent and future warming might promote an expansion of this evergreen dwarf shrub, mainly through densification of existing shrub patches, at High Arctic sites with sufficient winter snow cover and ample water supply during summer from melting snow and ice as well as thawing permafrost, contrasting earlier notions of limited shrub growth sensitivity to

  17. Phenology and cover of plant growth forms predict herbivore habitat selection in a high latitude ecosystem.

    PubMed

    Iversen, Marianne; Fauchald, Per; Langeland, Knut; Ims, Rolf A; Yoccoz, Nigel G; Bråthen, Kari Anne

    2014-01-01

    The spatial and temporal distribution of forage quality is among the most central factors affecting herbivore habitat selection. Yet, for high latitude areas, forage quantity has been found to be more important than quality. Studies on large ungulate foraging patterns are faced with methodological challenges in both assessing animal movements at the scale of forage distribution, and in assessing forage quality with relevant metrics. Here we use first-passage time analyses to assess how reindeer movements relate to forage quality and quantity measured as the phenology and cover of growth forms along reindeer tracks. The study was conducted in a high latitude ecosystem dominated by low-palatable growth forms. We found that the scale of reindeer movement was season dependent, with more extensive area use as the summer season advanced. Small-scale movement in the early season was related to selection for younger stages of phenology and for higher abundances of generally phenologically advanced palatable growth forms (grasses and deciduous shrubs). Also there was a clear selection for later phenological stages of the most dominant, yet generally phenologically slow and low-palatable growth form (evergreen shrubs). As the summer season advanced only quantity was important, with selection for higher quantities of one palatable growth form and avoidance of a low palatable growth form. We conclude that both forage quality and quantity are significant predictors to habitat selection by a large herbivore at high latitude. The early season selectivity reflected that among dominating low palatability growth forms there were palatable phenological stages and palatable growth forms available, causing herbivores to be selective in their habitat use. The diminishing selectivity and the increasing scale of movement as the season developed suggest a response by reindeer to homogenized forage availability of low quality.

  18. Phenology and Cover of Plant Growth Forms Predict Herbivore Habitat Selection in a High Latitude Ecosystem

    PubMed Central

    Fauchald, Per; Langeland, Knut; Ims, Rolf A.; Yoccoz, Nigel G.; Bråthen, Kari Anne

    2014-01-01

    The spatial and temporal distribution of forage quality is among the most central factors affecting herbivore habitat selection. Yet, for high latitude areas, forage quantity has been found to be more important than quality. Studies on large ungulate foraging patterns are faced with methodological challenges in both assessing animal movements at the scale of forage distribution, and in assessing forage quality with relevant metrics. Here we use first-passage time analyses to assess how reindeer movements relate to forage quality and quantity measured as the phenology and cover of growth forms along reindeer tracks. The study was conducted in a high latitude ecosystem dominated by low-palatable growth forms. We found that the scale of reindeer movement was season dependent, with more extensive area use as the summer season advanced. Small-scale movement in the early season was related to selection for younger stages of phenology and for higher abundances of generally phenologically advanced palatable growth forms (grasses and deciduous shrubs). Also there was a clear selection for later phenological stages of the most dominant, yet generally phenologically slow and low-palatable growth form (evergreen shrubs). As the summer season advanced only quantity was important, with selection for higher quantities of one palatable growth form and avoidance of a low palatable growth form. We conclude that both forage quality and quantity are significant predictors to habitat selection by a large herbivore at high latitude. The early season selectivity reflected that among dominating low palatability growth forms there were palatable phenological stages and palatable growth forms available, causing herbivores to be selective in their habitat use. The diminishing selectivity and the increasing scale of movement as the season developed suggest a response by reindeer to homogenized forage availability of low quality. PMID:24972188

  19. Predators select against high growth rates and risk-taking behaviour in domestic trout populations.

    PubMed Central

    Biro, Peter A.; Abrahams, Mark V.; Post, John R.; Parkinson, Eric A.

    2004-01-01

    Domesticated (farm) salmonid fishes display an increased willingness to accept risk while foraging, and achieve high growth rates not observed in nature. Theory predicts that elevated growth rates in domestic salmonids will result in greater risk-taking to access abundant food, but low survival in the presence of predators. In replicated whole-lake experiments, we observed that domestic trout (selected for high growth rates) took greater risks while foraging and grew faster than a wild strain. However, survival consequences for greater growth rates depended upon the predation environment. Domestic trout experienced greater survival when risk was low, but lower survival when risk was high. This suggests that animals with high intrinsic growth rates are selected against in populations with abundant predators, explaining the absence of such phenotypes in nature. This is, to our knowledge, the first large-scale field experiment to directly test this theory and simultaneously quantify the initial invasibility of domestic salmonid strains that escape into the wild from aquaculture operations, and the ecological conditions affecting their survival. PMID:15539348

  20. Maintaining High Availability in Distributed Mobile Systems

    DTIC Science & Technology

    2009-09-01

    systems, formal standards . Retrieved August 29, 2009, from IEEEXplore : http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=225554&isnum ber=5883...Systems. Retrieved August 29, 2009, from IEEEXplore : http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=73717&isnumb er=2482 Darroch, J. (2006

  1. Maintaining High Assurance in Asynchronous Messaging

    DTIC Science & Technology

    2015-10-24

    assurance environment. Index Terms—Asynchronous Communication, Publish Subscribe, IT Security, Encryption, Key Management I. INTRODUCTION...synchronous communication take place in or how these relate to each other. It is possible to implement synchronous communication using an asynchronous...continuing its processing. At the completion of message transmission, the sender does not know when or whether the receiver received it . The message

  2. Colony-live —a high-throughput method for measuring microbial colony growth kinetics— reveals diverse growth effects of gene knockouts in Escherichia coli

    PubMed Central

    2014-01-01

    Background Precise quantitative growth measurements and detection of small growth changes in high-throughput manner is essential for fundamental studies of bacterial cell. However, an inherent tradeoff for measurement quality in high-throughput methods sacrifices some measurement quality. A key challenge has been how to enhance measurement quality without sacrificing throughput. Results We developed a new high-throughput measurement system, termed Colony-live. Here we show that Colony-live provides accurate measurement of three growth values (lag time of growth (LTG), maximum growth rate (MGR), and saturation point growth (SPG)) by visualizing colony growth over time. By using a new normalization method for colony growth, Colony-live gives more precise and accurate growth values than the conventional method. We demonstrated the utility of Colony-live by measuring growth values for the entire Keio collection of Escherichia coli single-gene knockout mutants. By using Colony-live, we were able to identify subtle growth defects of single-gene knockout mutants that were undetectable by the conventional method quantified by fixed time-point camera imaging. Further, Colony-live can reveal genes that influence the length of the lag-phase and the saturation point of growth. Conclusions Measurement quality is critical to achieving the resolution required to identify unique phenotypes among a diverse range of phenotypes. Sharing high-quality genome-wide datasets should benefit many researchers who are interested in specific gene functions or the architecture of cellular systems. Our Colony-live system provides a new powerful tool to accelerate accumulation of knowledge of microbial growth phenotypes. PMID:24964927

  3. High-yield chemical vapor deposition growth of high-quality large-area AB-stacked bilayer graphene.

    PubMed

    Liu, Lixin; Zhou, Hailong; Cheng, Rui; Yu, Woo Jong; Liu, Yuan; Chen, Yu; Shaw, Jonathan; Zhong, Xing; Huang, Yu; Duan, Xiangfeng

    2012-09-25

    Bernal-stacked (AB-stacked) bilayer graphene is of significant interest for functional electronic and photonic devices due to the feasibility to continuously tune its band gap with a vertical electric field. Mechanical exfoliation can be used to produce AB-stacked bilayer graphene flakes but typically with the sizes limited to a few micrometers. Chemical vapor deposition (CVD) has been recently explored for the synthesis of bilayer graphene but usually with limited coverage and a mixture of AB- and randomly stacked structures. Herein we report a rational approach to produce large-area high-quality AB-stacked bilayer graphene. We show that the self-limiting effect of graphene growth on Cu foil can be broken by using a high H(2)/CH(4) ratio in a low-pressure CVD process to enable the continued growth of bilayer graphene. A high-temperature and low-pressure nucleation step is found to be critical for the formation of bilayer graphene nuclei with high AB stacking ratio. A rational design of a two-step CVD process is developed for the growth of bilayer graphene with high AB stacking ratio (up to 90%) and high coverage (up to 99%). The electrical transport studies demonstrate that devices made of the as-grown bilayer graphene exhibit typical characteristics of AB-stacked bilayer graphene with the highest carrier mobility exceeding 4000 cm(2)/V · s at room temperature, comparable to that of the exfoliated bilayer graphene.

  4. High-level construal benefits, meaning making, and posttraumatic growth in cancer patients.

    PubMed

    Wang, Yu; Gan, Yiqun; Miao, Miao; Ke, Qin; Li, Wenju; Zhang, Zijin; Cheng, Gang

    2016-10-01

    The present study sought to explore the role of meaning making and high-level construal in the relationship between meaning discrepancy and posttraumatic growth among Chinese cancer patients. The participants were 193 individuals diagnosed with cancer. Meaning discrepancy, meaning making, high-level construal in meaning making, and posttraumatic growth were measured. Bootstrapping and structural equation modeling were performed to test the mediation effects of high-level construal on the meaning-making process. Mediation analysis revealed that perceived discrepancies were associated with individuals' meaning-making efforts. Meaning-making efforts prompted participants to adopt a high-level construal orientation, which in turn enhanced posttraumatic growth. Our study empirically tested construal level theory in a population suffering from severe chronic trauma. The results demonstrate the important role of high-level construal in the meaning-making process of cancer patients, suggesting a specific effective strategy to foster posttraumatic growth. It seems encouraging to indicate that adopting such high-level construal may be included as part of psychological interventions for cancer patients.

  5. High-resistance GaN epilayers with low dislocation density via growth mode modification

    NASA Astrophysics Data System (ADS)

    Xu, Z. Y.; Xu, F. J.; Wang, J. M.; Lu, L.; Yang, Z. J.; Wang, X. Q.; Shen, B.

    2016-09-01

    High-resistance GaN with low dislocation density adopting growth mode modification has been investigated by metalorganic chemical vapor deposition. The sheet resistance of the order of 1016 Ω/sq has been achieved at room temperature by diminishing the oxygen impurity level close to the substrate with an AlN blocking layer. Attributed to this method which offers more freedom to tailor the growth mode, a three-dimensional (3D) growth process is introduced by adjusting the growth pressure and temperature at the initial stage of the GaN epitaxy to improve the crystalline quality. The large 3D GaN grains formed during this period roughen the surface, and the following coalescence of the GaN grains causes threading dislocations bending, which finally remarkably reduces the dislocation density.

  6. Initial development of a high-pressure crystal growth facility: Center director's discretionary fund

    NASA Technical Reports Server (NTRS)

    Szofran, F. R.; Lehoczky, S. L.; Cobb, S. D.; Gillies, D. C.

    1993-01-01

    A low-cost, flexible, high-pressure (600 psi) system for crystal growth and related thermophysical properties measurements was designed, assembled, and tested. The furnace system includes a magnetically coupled translation mechanism that eliminates the need for a high-pressure mechanical feedthru. The system is currently being used for continuing crystal growth experiments and thermophysical properties measurements on several material systems including Hg(1-x)Cd(x)Te, Hg(1-x)Zn(x)Te, and Hg(1-x)Zn(x)Se.

  7. Continuous microbial cultures maintained by electronically-controlled device

    NASA Technical Reports Server (NTRS)

    Eisler, W. J., Jr.; Webb, R. B.

    1967-01-01

    Photocell-controlled instrument maintains microbial culture. It uses commercially available chemostat glassware, provides adequate aeration through bubbling of the culture, maintains the population size and density, continuously records growth rates over small increments of time, and contains a simple, sterilizable nutrient control mechanism.

  8. Protein folding failure sets high-temperature limit on growth of phage P22 in Salmonella enterica serovar Typhimurium.

    PubMed

    Pope, Welkin H; Haase-Pettingell, Cameron; King, Jonathan

    2004-08-01

    The high-temperature limit for growth of microorganisms differs greatly depending on their species and habitat. The importance of an organism's ability to manage thermal stress is reflected in the ubiquitous distribution of the heat shock chaperones. Although many chaperones function to reduce protein folding defects, it has been difficult to identify the specific protein folding pathways that set the high-temperature limit of growth for a given microorganism. We have investigated this for a simple system, phage P22 infection of Salmonella enterica serovar Typhimurium. Production of infectious particles exhibited a broad maximum of 150 phage per cell when host cells were grown at between 30 and 39 degrees C in minimal medium. Production of infectious phage declined sharply in the range of 40 to 41 degrees C, and at 42 degrees C, production had fallen to less than 1% of the maximum rate. The host cells maintained optimal division rates at these temperatures. The decrease in phage infectivity was steeper than the loss of physical particles, suggesting that noninfectious particles were formed at higher temperatures. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed a decrease in the tailspike adhesins assembled on phage particles purified from cultures incubated at higher temperatures. The infectivity of these particles was restored by in vitro incubation with soluble tailspike trimers. Examination of tailspike folding and assembly in lysates of phage-infected cells confirmed that the fraction of polypeptide chains able to reach the native state in vivo decreased with increasing temperature, indicating a thermal folding defect rather than a particle assembly defect. Thus, we believe that the folding pathway of the tailspike adhesin sets the high-temperature limit for P22 formation in Salmonella serovar Typhimurium.

  9. Higher Ammonium Transamination Capacity Can Alleviate Glutamate Inhibition on Winter Wheat (Triticum aestivum L.) Root Growth under High Ammonium Stress

    PubMed Central

    Liu, Yang; Tian, Zhongwei; Muhammad, Abid; Zhang, Yixuan; Jiang, Dong; Cao, Weixing; Dai, Tingbo

    2016-01-01

    Most of the studies about NH4+ stress mechanism simply address the effects of free NH4+, failing to recognize the changed nitrogen assimilation products. The objective of this study was to elucidate the effects of glutamate on root growth under high ammonium (NH4+) conditions in winter wheat (Triticum aestivum L.). Hydroponic experiments were conducted using two wheat cultivars, AK58 (NH4+-sensitive) and Xumai25 (NH4+-tolerant) with either 5 mM NH4+ nitrogen (AN) as stress treatment or 5 mM nitrate (NO3-) nitrogen as control. To evaluate the effects of NH4+-assimilation products on plant growth, 1 μM L-methionine sulfoximine (MSO) (an inhibitor of glutamine synthetase (GS)) and 1 mM glutamates (a primary N assimilation product) were added to the solutions, respectively. The AN significantly reduced plant biomass, total root length, surface area and root volume in both cultivars, but less effect was observed in Xumai25. The inhibition effects were alleviated by the application of MSO but strengthened by the application of glutamate. The AN increased the activities of GS, glutamate dehydrogenase (GDH) in both cultivars, resulting in higher glutamate contents. However, its contents were decreased by the application of MSO. Compared to AK58, Xumai25 showed lower glutamate contents due to its higher activities of glutamic-oxaloacetic transaminase (GOT) and glutamic-pyruvic transaminase (GPT). With the indole-3-acetic acid (IAA) contents decreasing in roots, the ratio of shoot to root in IAA was increased, and further increased by the application of glutamate, and reduced by the application of MSO, but the ratio was lower in Xumai25. Meanwhile, the total soluble sugar contents and its root to shoot ratio also showed similar trends. These results indicate that the NH4+-tolerant cultivar has a greater transamination ability to prevent glutamate over-accumulation to maintain higher IAA transport ability, and consequently promoted soluble sugar transport to roots, further

  10. Noncontact monitoring of fatigue crack growth using high frequency guided waves

    NASA Astrophysics Data System (ADS)

    Masserey, B.; Fromme, P.

    2014-03-01

    The development of fatigue cracks at fastener holes due to stress concentration is a common problem in aircraft maintenance. This contribution investigates the use of high frequency guided waves for the non-contact monitoring of fatigue crack growth in tensile, aluminium specimens. High frequency guided ultrasonic waves have a good sensitivity for defect detection and can propagate along the structure, thus having the potential for the inspection of difficult to access parts by means of non-contact measurements. Experimentally the required guided wave modes are excited using standard wedge transducers and measured using a laser interferometer. The growth of fatigue cracks during cyclic loading was monitored optically and the resulting changes in the signal caused by crack growth are quantified. Full three-dimensional simulation of the scattering of the high frequency guided ultrasonic waves at the fastener hole and crack has been implemented using the Finite Difference (FD) method. The comparison of the results shows a good agreement of the measured and predicted scattered field of the guided wave at quarter-elliptical and through-thickness fatigue cracks. The measurements show a good sensitivity for the early detection of fatigue damage and for the monitoring of fatigue crack growth at a fastener hole. The sensitivity and repeatability are ascertained, and the robustness of the methodology for practical in-situ ultrasonic monitoring of fatigue crack growth is discussed.

  11. High nitrate supply reduces growth in maize, from cell to whole plant.

    PubMed

    Saiz-Fernández, Iñigo; De Diego, Nuria; Sampedro, Maria Carmen; Mena-Petite, Amaia; Ortiz-Barredo, Amaia; Lacuesta, Maite

    2015-01-15

    Nitrogen (N) is an essential macronutrient that limits agricultural productivity, and both low and high N supply have been suggested to alter plant growth. The overall aim of this work is to study the impact of nitrate (NO3(-)) in maize yield and the possible causes that induce this alteration. High NO3(-) doses did not increase the yield of maize grown neither in the field nor under controlled conditions. In fact, plants grown under controlled conditions for 45 days with NO3(-) concentrations over 5mM showed a decrease in biomass production. This reduction was perceptible in shoots prior to roots, where phytomer expansion was reduced. Cell size and number were also reduced in the leaves of plants with high NO3(-). This alteration was correlated with the increase of 1-aminocyclopropane-1-carboxylic acid in leaves, which was probably translocated from the roots in order to synthesize ethylene. Cytokinins (CKs) also showed a relevant role in this inhibitory effect, increasing in high NO3(-) plants with a reduction in root and shoot growth, inhibition of apical dominance and a strong decrease of leaf expansion, symptoms described previously as "CK syndrome". We propose that high NO3(-) inhibits maize growth by causing hormonal alterations that modify plant growth from cell to whole plant. Copyright © 2014 Elsevier GmbH. All rights reserved.

  12. Maintainability Program Requirements for Space Systems

    NASA Technical Reports Server (NTRS)

    1987-01-01

    This document is established to provide common general requirements for all NASA programs to: design maintainability into all systems where maintenance is a factor in system operation and mission success; and ensure that maintainability characteristics are developed through the systems engineering process. These requirements are not new. Design for ease of maintenance and minimization of repair time have always been fundamental requirements of the systems engineering process. However, new or reusable orbital manned and in-flight maintainable unmanned space systems demand special emphasis on maintainability, and this document has been prepared to meet that need. Maintainability requirements on many NASA programs differ in phasing and task emphasis from requirements promulgated by other Government agencies. This difference is due to the research and development nature of NASA programs where quantities produced are generally small; therefore, the depth of logistics support typical of many programs is generally not warranted. The cost of excessive maintenance is very high due to the logistics problems associated with the space environment. The ability to provide timely maintenance often involves safety considerations for manned space flight applications. This document represents a basic set of requirements that will achieve a design for maintenance. These requirements are directed primarily at manned and unmanned orbital space systems. To be effective, maintainability requirements should be tailored to meet specific NASA program and project needs and constraints. NASA activities shall invoke the requirements of this document consistent with program planning in procurements or on inhouse development efforts.

  13. Highly ordered self-assembled nanoscale periodic faceting in GaAs(631) homoepitaxial growth

    NASA Astrophysics Data System (ADS)

    Cruz-Hernández, E.; Shimomura, S.; Méndez-García, V. H.

    2012-08-01

    We report on the self-assembly of large-order-correlated nanoscale faceting on GaAs(631)A substrates grown by molecular beam epitaxy. The surface morphology of the grown samples as a function of the growth temperature and the As-beam equivalent pressure was studied using atomic force microscopy. A two-dimensional autocorrelation function analysis was performed in order to quantitatively determine the uniformity of the surface corrugation. By optimizing the growth conditions, correlated faceted areas as large as 1.7 × 1.7 μm2 are obtained. The highly ordered surface corrugation discussed here provides useful insights to prepare highly ordered facet planes for the self organized growth of quantum wires.

  14. Highly ordered self-assembled nanoscale periodic faceting in GaAs(631) homoepitaxial growth

    SciTech Connect

    Cruz-Hernandez, E.; Mendez-Garcia, V. H.; Shimomura, S.

    2012-08-13

    We report on the self-assembly of large-order-correlated nanoscale faceting on GaAs(631)A substrates grown by molecular beam epitaxy. The surface morphology of the grown samples as a function of the growth temperature and the As-beam equivalent pressure was studied using atomic force microscopy. A two-dimensional autocorrelation function analysis was performed in order to quantitatively determine the uniformity of the surface corrugation. By optimizing the growth conditions, correlated faceted areas as large as 1.7 Multiplication-Sign 1.7 {mu}m{sup 2} are obtained. The highly ordered surface corrugation discussed here provides useful insights to prepare highly ordered facet planes for the self organized growth of quantum wires.

  15. Maintaining quality in online education.

    PubMed

    Moore, Janet C

    2007-01-01

    Higher education is adapting to new technologies and to the evolving pedagogies that accompany change. Maintaining quality begins with identifying purpose and assessing progress. Using the Sloan Consortium's quality framework, this article provides resources for measuring quality in online environments.

  16. Growth of high purity N-polar (In,Ga)N films

    NASA Astrophysics Data System (ADS)

    Lund, Cory; Nakamura, Shuji; DenBaars, Steven P.; Mishra, Umesh K.; Keller, Stacia

    2017-04-01

    In this work, secondary ion mass spectroscopy was used to study carbon and oxygen impurity incorporation in N-polar [000-1] GaN films grown by MOCVD. The effects of growth temperature, V/III ratio, and precursor flows were studied within a regime relevant to low temperature (In,Ga)N:Mg growth for device structures containing high indium concentrations. For films grown without magnesium, oxygen levels were between 3 and 8×1016 cm-3 and did not depend strongly on the growth conditions. Mg-doped films yielded higher oxygen concentrations ranging from 8×1016 to 4×1017 cm-3 depending on the gallium and magnesium precursor flow rates. The carbon concentration in the films varied significantly with different growth conditions, and was most affected by the growth temperature and the V/III ratio. With careful tuning of the growth parameters carbon and oxygen concentrations of 2 and 4×1016 cm-3, respectively, were achievable under a wide range of conditions.

  17. Patterning Expression of Regenerative Growth Factors Using High Intensity Focused Ultrasound

    PubMed Central

    Wilson, Christopher G.; Martín-Saavedra, Francisco M.; Padilla, Frédéric; Fabiilli, Mario L.; Zhang, Man; Baez, Alexander M.; Bonkowski, Christopher J.; Kripfgans, Oliver D.; Voellmy, Richard; Vilaboa, Nuria; Fowlkes, J. Brian

    2014-01-01

    Temporal and spatial control of growth factor gradients is critical for tissue patterning and differentiation. Reinitiation of this developmental program is also required for regeneration of tissues during wound healing and tissue regeneration. Devising methods for reconstituting growth factor gradients remains a central challenge in regenerative medicine. In the current study we develop a novel gene therapy approach for temporal and spatial control of two important growth factors in bone regeneration, vascular endothelial growth factor, and bone morphogenetic protein 2, which involves application of high intensity focused ultrasound to cells engineered with a heat-activated- and ligand-inducible gene switch. Induction of transgene expression was tightly localized within cell-scaffold constructs to subvolumes of ∼30 mm3, and the amplitude and projected area of transgene expression was tuned by the intensity and duration of ultrasound exposure. Conditions for ultrasound-activated transgene expression resulted in minimal cytotoxicity and scaffold damage. Localized regions of growth factor expression also established gradients in signaling activity, suggesting that patterns of growth factor expression generated by this method will have utility in basic and applied studies on tissue development and regeneration. PMID:24460731

  18. Importance of cell damage causing growth delay for high pressure inactivation of Saccharomyces cerevisiae

    NASA Astrophysics Data System (ADS)

    Nanba, Masaru; Nomura, Kazuki; Nasuhara, Yusuke; Hayashi, Manabu; Kido, Miyuki; Hayashi, Mayumi; Iguchi, Akinori; Shigematsu, Toru; Hirayama, Masao; Ueno, Shigeaki; Fujii, Tomoyuki

    2013-06-01

    A high pressure (HP) tolerant (barotolerant) mutant a2568D8 and a variably barotolerant mutant a1210H12 were generated from Saccharomyces cerevisiae using ultra-violet mutagenesis. The two mutants, a barosensitive mutant a924E1 and the wild-type strain, were pressurized (225 MPa), and pressure inactivation behavior was analyzed. In the wild-type strain, a proportion of the growth-delayed cells were detected after exposure to HP. In a924E1, the proportion of growth-delayed cells significantly decreased compared with the wild-type. In a2568D8, the proportion of growth-delayed cells increased and the proportion of inactivated cells decreased compared with the wild-type. In a1210H12, the growth-delayed cells could not be detected within 120 s of exposure to HP. The proportion of growth-delayed cells, which incurred the damage, would affect the survival ratio by HP. These results suggested that cellular changes in barotolerance caused by mutations are remarkably affected by the ability to recover from cellular damage, which results in a growth delay.

  19. High quality chemical vapor deposition diamond growth on iron and stainless steel substrates

    NASA Astrophysics Data System (ADS)

    Nakamura, Eri; Hirakuri, Kenji K.; Ohyama, Manabu; Friedbacher, Gernot; Mutsukura, Nobuki

    2002-09-01

    Due to the catalytic effect and the rapid diffusion coefficients of carbon species into iron-based materials such as iron and 18-8 stainless steel [18% chrome (Cr) and 8% nickel (Ni)], it is very difficult to produce diamond grains on such substrates. However, diamond growth on iron-based materials is extremely important for mechanical and electrical applications, since these materials are widely used in industrial field and fundamental science. In our previous study, diamond nucleation and subsequent growth have been precisely controlled by the residence time of the source gas, which is an essential parameter. Here, we have carried out diamond growth on iron-based materials using the hot-filament chemical vapor deposition technique with varying residence times. At low residence times, diamond grains with practically useful growth rate are grown. The growth rate of diamond grains on stainless steel substrates was a factor of about 10 greater than that on a regular silicon substrate at optimum conditions. At optimized conditions, diamond growths with high crystalline quality on stainless steel substrates were confirmed by Raman spectroscopy and scanning electron microscopy. The full width of half maximums of the Raman peaks for diamonds grown in this study are comparable to the ones of natural diamonds.

  20. Investigating the Effects of Anisotropic Mass Transport on Dendrite Growth in High Energy Density Lithium Batteries

    SciTech Connect

    Tan, Jinwang; Tartakovsky, Alexandre M.; Ferris, Kim F.; Ryan, Emily M.

    2016-01-01

    Dendrite formation on the electrode surface of high energy density lithium (Li) batteries causes safety problems and limits their applications. Suppressing dendrite growth could significantly improve Li battery performance. Dendrite growth and morphology is a function of the mixing in the electrolyte near the anode interface. Most research into dendrites in batteries focuses on dendrite formation in isotropic electrolytes (i.e., electrolytes with isotropic diffusion coefficient). In this work, an anisotropic diffusion reaction model is developed to study the anisotropic mixing effect on dendrite growth in Li batteries. The model uses a Lagrangian particle-based method to model dendrite growth in an anisotropic electrolyte solution. The model is verified by comparing the numerical simulation results with analytical solutions, and its accuracy is shown to be better than previous particle-based anisotropic diffusion models. Several parametric studies of dendrite growth in an anisotropic electrolyte are performed and the results demonstrate the effects of anisotropic transport on dendrite growth and morphology, and show the possible advantages of anisotropic electrolytes for dendrite suppression.

  1. Effect of moderate high temperature on the vegetative growth and potassium allocation in olive plants.

    PubMed

    Benlloch-González, María; Quintero, José Manuel; Suárez, María Paz; Sánchez-Lucas, Rosa; Fernández-Escobar, Ricardo; Benlloch, Manuel

    2016-12-01

    There is little information about the prolonged effect of a moderately high temperature on the growth of olive (Olea europaea L.). It has been suggested that when the temperature of the air rises above 35°C the shoot growth of olive is inhibited while there is any reference on how growth is affected when the soil is warmed. In order to examine these effects, mist-cuttings and young plants generated from seeds were grown under moderate high temperature (37°C) for 64 and 42days respectively. In our study, plant dry matter accumulation was reduced when the temperature of both the air and the root medium was moderately high. However, when the temperature of the root medium was 25°C, the inhibitory effect of air high temperature on plant growth was not observed. The exposure of both the aerial part and the root to moderate high temperature also reduced the accumulation of K(+) in the stem and the root, the water use efficiency and leaf relative water content. However, when only the aerial part was exposed to moderate high temperature, the accumulation of K(+) in the stem, the water use efficiency and leaf relative water content were not modified. The results from this study suggest that the olive is very efficient in regulating the water and potassium transport through the plant when only the atmosphere surrounding the aerial part is warmed up. However, an increase in the soil temperature decrease root K(+) uptake and its transport to the aerial parts resulting in a reduction in shoot water status and growth.

  2. Grain growth behavior and high-temperature high-strain-rate tensile ductility of iridium alloy DOP-26

    SciTech Connect

    McKamey, C.G.; Gubbi, A.N.; Lin, Y.; Cohron, J.W.; Lee, E.H.; George, E.P.

    1998-04-01

    This report summarizes results of studies conducted to date under the Iridium Alloy Characterization and Development subtask of the Radioisotope Power System Materials Production and Technology Program to characterize the properties of the new-process iridium-based DOP-26 alloy used for the Cassini space mission. This alloy was developed at Oak Ridge National Laboratory (ORNL) in the early 1980`s and is currently used by NASA for cladding and post-impact containment of the radioactive fuel in radioisotope thermoelectric generator (RTG) heat sources which provide electric power for interplanetary spacecraft. Included within this report are data generated on grain growth in vacuum or low-pressure oxygen environments; a comparison of grain growth in vacuum of the clad vent set cup material with sheet material; effect of grain size, test temperature, and oxygen exposure on high-temperature high-strain-rate tensile ductility; and grain growth in vacuum and high-temperature high-strain-rate tensile ductility of welded DOP-26. The data for the new-process material is compared to available old-process data.

  3. Tracking Growth: Studying First-Year Teacher Development under a High-Stakes Evaluation System

    ERIC Educational Resources Information Center

    Maier, Adam; Grogan, Erin

    2013-01-01

    Students who have more effective teachers are more likely to attend college, earn a higher salary, and live in higher socioeconomic neighborhoods (Chetty, Friedman, & Rockoff, 2012). As such, teacher effectiveness is critically important, and identifying teachers who demonstrate high potential for growth in their first year of teaching could…

  4. Environmentally assisted crack growth rates of high-strength aluminum alloys

    NASA Astrophysics Data System (ADS)

    Connolly, Brain J.; Deffenbaugh, Kristen L.; Moran, Angela L.; Koul, Michelle G.

    2003-01-01

    The scope of this project is to evaluate the environmentally assisted long crack growth behavior of candidate high-strength aluminum alloys/tempers, specifically AA7150-T7751 and AA7040-T7651, for consideration as viable replacements/refurbishment for stress-corrosion cracking in susceptible AA7075-T6 aircraft components found in aging aircraft systems.

  5. Synthesis and Characterization of High-Purity Tellurium Nanowires via Self-seed-Assisted Growth Approach

    NASA Astrophysics Data System (ADS)

    Li, Ying; Zhao, Wen-yu; Mu, Xin; Liu, Xing; He, Dan-qi; Zhu, Wan-ting; Zhang, Qing-jie

    2016-03-01

    Nanowires have attracted intense attention in recent years due to their novel physical properties. In this work, we prepare high-purity tellurium nanowires through the self-seed-assisted growth method previously developed by us. The tellurium seeds were firstly synthesized by reducing Na2TeO3 in the ice water with NaBH4. The high-purity tellurium nanowires with a diameter of 40-50 nm and a length of several tens of micrometers were then grown on tellurium seeds by reducing Na2TeO3 with hydrazine hydrate. X-ray diffraction, scanning electron microscopy and transmission electron microscopy were employed to characterize the crystal structure, microstructure, and growth direction of tellurium seeds and nanowires. The effects of temperature, time, surfactant and tellurium seeds on microstructures of tellurium nanowires has also been investigated. The synthesis conditions of tellurium seeds and nanowires was optimized. The selected area electron diffraction pattern confirms that the growth direction of tellurium nanowires is parallel to [0001] direction. It was discovered that high-purity tellurium nanowires with high aspect ratio can be synthesized by precisely controlling the temperature to adjust the nucleation rate of the tellurium nuclei, selecting the appropriate surfactant to induce the coordination along the macromolecular chain, and using tellurium seeds as the templates of the epitaxial growth of tellurium nuclei.

  6. Identification of High Growth Occupations. Job Corps Vocational Education Offerings Review. Documentation Report No. 2.

    ERIC Educational Resources Information Center

    Manpower Administration (DOL), Washington, DC. Job Corps.

    As part of a multiphased evaluation of vocational training provided by the Job Corps in fiscal year 1982, a study examined Job Corps practices for identifying high growth occupations. At least for the present, national projections are the main source of information available to Job Corps planners for use in assessing future vocational training…

  7. High-grade serous ovarian cancer cell lines exhibit heterogeneous responses to growth factor stimulation.

    PubMed

    Bourgeois, Danielle L; Kabarowski, Karl A; Porubsky, Veronica L; Kreeger, Pamela K

    2015-01-01

    The factors driving the onset and progression of ovarian cancer are not well understood. Recent reports have identified cell lines that are representative of the genomic pattern of high-grade serous ovarian cancer (HGSOC), in which greater than 90 % of tumors have a mutation in TP53. However, many of these representative cell lines have not been widely used so it is unclear if these cell lines capture the variability that is characteristic of the disease. We investigated six TP53-mutant HGSOC cell lines (Caov3, Caov4, OV90, OVCA432, OVCAR3, and OVCAR4) for migration, MMP2 expression, proliferation, and VEGF secretion, behaviors that play critical roles in tumor progression. In addition to comparing baseline variation between the cell lines, we determined how these behaviors changed in response to four growth factors implicated in ovarian cancer progression: HB-EGF, NRG1β, IGF1, and HGF. Baseline levels of each behavior varied across the cell lines and this variation was comparable to that seen in tumors. All four growth factors impacted cell proliferation or VEGF secretion, and HB-EGF, NRG1β, and HGF impacted wound closure or MMP2 expression in at least two cell lines. Growth factor-induced responses demonstrated substantial heterogeneity, with cell lines sensitive to all four growth factors, a subset of the growth factors, or none of the growth factors, depending on the response of interest. Principal component analysis demonstrated that the data clustered together based on cell line rather than growth factor identity, suggesting that response is dependent on intrinsic qualities of the tumor cell rather than the growth factor. Significant variation was seen among the cell lines, consistent with the heterogeneity of HGSOC.

  8. New Crystal-Growth Methods for Producing Lattice-Matched Substrates for High-Temperature Superconductors

    SciTech Connect

    Boatner, L.A.

    2008-06-24

    This effort addressed the technical problem of identifying and growing, on a commercial scale, suitable single-crystal substrates for the subsequent deposition of epitaxial thin films of high temperature semiconductors such as GaN/AlN. The lack of suitable lattice-matched substrate materials was one of the major problem areas in the development of semiconducting devices for use at elevated temperatures as well as practical opto-electronic devices based on Al- and GaN technology. Such lattice-matched substrates are necessary in order to reduce or eliminate high concentrations of defects and dislocations in GaN/AlN and related epitaxial thin films. This effort concentrated, in particular, on the growth of single crystals of ZnO for substrate applications and it built on previous ORNL experience in the chemical vapor transport growth of large single crystals of zinc oxide. This combined expertise in the substrate growth area was further complemented by the ability of G. Eres and his collaborators to deposit thin films of GaN on the subject substrates and the overall ORNL capability for characterizing the quality of such films. The research effort consisted of research on the growth of two candidate substrate materials in conjunction with concurrent research on the growth and characterization of GaN films, i.e. the effort combined bulk crystal growth capabilities in the area of substrate production at both ORNL and the industrial partner, Commercial Crystal Growth Laboratories (CCL), Naples, Florida, with the novel thin-film deposition techniques previously developed in the ORNL SSD.

  9. Controlled growth of high-quality graphene using hot-filament chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Selvakumar, N.; Vadivel, B.; Rao, D. V. Sridhara; Krupanidhi, S. B.; Barshilia, Harish C.

    2016-11-01

    High-quality graphene was grown on polycrystalline copper (Cu) foils (1 cm × 1 cm) using hot-filament chemical vapor deposition method. The role of process parameters such as gas flow rates (methane and hydrogen), growth temperatures (filament and substrate) and durations on the growth of graphene was studied. The process parameters were also optimized to grow monolayer, bilayer and multilayer graphene in a controlled manner, and a growth mechanism was deduced from the experimental results. The presence of graphene on Cu foils was confirmed using X-ray photoelectron spectroscopy, micro-Raman spectroscopy, field-emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) techniques. FESEM micrographs clearly showed that the graphene starts nucleating as hexagonal islands and later evolves as dendritic lobe-shaped islands with an increase in supersaturation. The TEM images substantiate the growth of monolayer, bilayer and multilayer graphene. The I 2D/ I G ratio = 2 confirmed the presence of the monolayer graphene and the absence of `D' peak in the Raman spectrum indicated the high purity of graphene grown on Cu foils. These results also show that the polycrystalline copper foil morphology has negligible effect on the growth of monolayer graphene.

  10. Growth of Single-Walled Carbon Nanotubes by High Melting Point Metal Oxide Catalysts

    NASA Astrophysics Data System (ADS)

    Qian, Yang; Xiang, Rong; An, Hua; Inoue, Taiki; Chiashi, Shohei; Maruyama, Shigeo

    We report on the growth of single-walled carbon nanotubes (SWNTs) from Co oxide catalysts. The concept is using the relatively lower mobility of metal oxide (than metal) to suppress catalyst aggregation at high temperatures. Compared to the SWNTs grown by pre-reduced catalysts, SWNTs grown from oxidized Co catalysts have shown narrower diameter distribution and smaller average diameter. Different growth parameters are discussed regarding the resulting morphology of SWNTs. Transmission electron microscopy (TEM) investigations reveal the information that Co catalysts are transformed to Co3O4 after reduction-calcination process. X-ray photoelectron spectroscopy (XPS) investigations indicate that Co3O4 has decomposed to CoO before growth at a typical growth temperature (800 ºC) in Ar atmosphere. We propose that CoO has higher melting point than Co and thus is more stable during the growth. Our results indicate that besides the bimetallic catalysts, monometallic catalytic system could also be useful in stabilizing the catalysts to grow chirality-specific SWNTs by transforming the relatively low melting point metal catalysts to high melting point metal oxide catalysts. Yang Qian was supported through ``Global Leader Program for Social Design and Management''.

  11. High altitude hypoxia as a factor that promotes tibial growth plate development in broiler chickens.

    PubMed

    Huang, Shucheng; Zhang, Lihong; Rehman, Mujeeb Ur; Iqbal, Muhammad Kashif; Lan, Yanfang; Mehmood, Khalid; Zhang, Hui; Qiu, Gang; Nabi, Fazul; Yao, Wangyuan; Wang, Meng; Li, Jiakui

    2017-01-01

    Tibial dyschondroplasia (TD) is one of the most common problems in the poultry industry and leads to lameness by affecting the proximal growth plate of the tibia. However, due to the unique environmental and geographical conditions of Tibet, no case of TD has been reported in Tibetan chickens (TBCs). The present study was designed to investigate the effect of high altitude hypoxia on blood parameters and tibial growth plate development in chickens using the complete blood count, morphology, and histological examination. The results of this study showed an undesirable impact on the overall performance, body weight, and mortality of Arbor Acres chickens (AACs) exposed to a high altitude hypoxic environment. However, AACs raised under hypoxic conditions showed an elevated number of red blood cells (RBCs) and an increase in hemoglobin and hematocrit values on day 14 compared to the hypobaric normoxia group. Notably, the morphology and histology analyses showed that the size of tibial growth plates in AACs was enlarged and that the blood vessel density was also higher after exposure to the hypoxic environment for 14 days, while no such change was observed in TBCs. Altogether, our results revealed that the hypoxic environment has a potentially new role in increasing the blood vessel density of proximal tibial growth plates to strengthen and enhance the size of the growth plates, which may provide new insights for the therapeutic manipulation of hypoxia in poultry TD.

  12. High altitude hypoxia as a factor that promotes tibial growth plate development in broiler chickens

    PubMed Central

    Huang, Shucheng; Zhang, Lihong; Rehman, Mujeeb Ur; Iqbal, Muhammad Kashif; Lan, Yanfang; Mehmood, Khalid; Zhang, Hui; Qiu, Gang; Nabi, Fazul; Yao, Wangyuan; Wang, Meng; Li, Jiakui

    2017-01-01

    Tibial dyschondroplasia (TD) is one of the most common problems in the poultry industry and leads to lameness by affecting the proximal growth plate of the tibia. However, due to the unique environmental and geographical conditions of Tibet, no case of TD has been reported in Tibetan chickens (TBCs). The present study was designed to investigate the effect of high altitude hypoxia on blood parameters and tibial growth plate development in chickens using the complete blood count, morphology, and histological examination. The results of this study showed an undesirable impact on the overall performance, body weight, and mortality of Arbor Acres chickens (AACs) exposed to a high altitude hypoxic environment. However, AACs raised under hypoxic conditions showed an elevated number of red blood cells (RBCs) and an increase in hemoglobin and hematocrit values on day 14 compared to the hypobaric normoxia group. Notably, the morphology and histology analyses showed that the size of tibial growth plates in AACs was enlarged and that the blood vessel density was also higher after exposure to the hypoxic environment for 14 days, while no such change was observed in TBCs. Altogether, our results revealed that the hypoxic environment has a potentially new role in increasing the blood vessel density of proximal tibial growth plates to strengthen and enhance the size of the growth plates, which may provide new insights for the therapeutic manipulation of hypoxia in poultry TD. PMID:28282429

  13. High-throughput dental biofilm growth analysis for multiparametric microenvironmental biochemical conditions using microfluidics.

    PubMed

    Lam, Raymond H W; Cui, Xin; Guo, Weijin; Thorsen, Todd

    2016-04-26

    Dental biofilm formation is not only a precursor to tooth decay, but also induces more serious systematic health problems such as cardiovascular disease and diabetes. Understanding the conditions promoting colonization and subsequent biofilm development involving complex bacteria coaggregation is particularly important. In this paper, we report a high-throughput microfluidic 'artificial teeth' device offering controls of multiple microenvironmental factors (e.g. nutrients, growth factors, dissolved gases, and seeded cell populations) for quantitative characteristics of long-term dental bacteria growth and biofilm development. This 'artificial teeth' device contains multiple (up to 128) incubation chambers to perform parallel cultivation and analyses (e.g. biofilm thickness, viable-dead cell ratio, and spatial distribution of multiple bacterial species) of bacteria samples under a matrix of different combinations of microenvironmental factors, further revealing possible developmental mechanisms of dental biofilms. Specifically, we applied the 'artificial teeth' to investigate the growth of two key dental bacteria, Streptococci species and Fusobacterium nucleatum, in the biofilm under different dissolved gas conditions and sucrose concentrations. Together, this high-throughput microfluidic platform can provide extended applications for general biofilm research, including screening of the biofilm properties developing under combinations of specified growth parameters such as seeding bacteria populations, growth medium compositions, medium flow rates and dissolved gas levels.

  14. A high-resolution monitoring network investigating stem growth of tropical forest trees

    NASA Astrophysics Data System (ADS)

    Hofhansl, F.; De Araujo, A. C.; DeLucia, E. H.

    2015-12-01

    The proportion of carbon (C) allocated to tree stems is an important determinant of the C sink-strength of global forest ecosystems. Understanding the mechanisms controlling stem growth is essential for parameterization of global vegetation models and to accurately predict C sequestration of forest ecosystems. However, we still lack a thorough understanding of intra-annual variations in stem growth of tropical forest ecosystems, which could be especially prone to projected climatic changes. We here present high-resolution data (≤ 6 µm; ≥ 1 min) from a novel monitoring network of wireless devices for automated measurement of expansion and contraction in tree diameter using a membrane potentiometer, as well as point dendrometers on phloem and xylem to analyze diurnal changes in stem growth. Our results indicate that diurnal changes in stem diameter were associated with sap flow and related to seasonal variations in daytime temperature and water availability, such that daily maximum stem growth was positively related to temperature during the wet season but showed the opposite trend during the onset of the dry season. We show that high-resolution monitoring of stem growth of tropical trees is crucial to determine the response to intra-annual climate variation and therefore will be key to accurately predict future responses of tropical aboveground C storage, and should be of special interest for tropical ecosystem research and earth system science.

  15. A High-Sensitivity Potential-Drop Technique for Fatigue Crack Growth Measurements,

    DTIC Science & Technology

    1979-08-01

    inappropriate to assume that crack growth characteristics at the surface are representative of crack behaviour in the specimen mid-thickness. 2.2 Ultrasonic...techniques has been described by several authors [23-25], and offers the advantages of high noise rejection and low current consumption . However, as the...Colonel B.C. Joshi, Military, Naval and Air Adviser, High Commission of India, Red Hill, A.C.T. Director, Defence Research Centre, Kuala Lumpur, Malaysia

  16. Highly Oriented Growth of Piezoelectric Thin Films on Silicon Using Two-Dimensional Nanosheets as Growth Template Layer.

    PubMed

    Nguyen, Minh D; Yuan, Huiyu; Houwman, Evert P; Dekkers, Matthijn; Koster, Gertjan; Ten Elshof, Johan E; Rijnders, Guus

    2016-11-16

    Ca2Nb3O10 (CNOns) and Ti0.87O2 (TiOns) metal oxide nanosheets (ns) are used as a buffer layer for epitaxial growth of piezoelectric capacitor stacks on Si and Pt/Ti/SiO2/Si (Pt/Si) substrates. Highly (001)- and (110)-oriented Pb(Zr0.52Ti0.48)O3 (PZT) films are achieved by utilizing CNOns and TiOns, respectively. The piezoelectric capacitors are characterized by polarization and piezoelectric hysteresis loops and by fatigue measurements. The devices fabricated with SrRuO3 top and bottom electrodes directly on nanosheets/Si have ferroelectric and piezoelectric properties well comparable with devices that use more conventional oxide buffer layers (stacks) such as YSZ, CeO2/YSZ, or SrTiO3 on Si. The devices grown on nanosheets/Pt/Si with Pt top electrodes show significantly improved polarization fatigue properties over those of similar devices grown directly on Pt/Si. The differences in properties are ascribed to differences in the crystalline structures and the density of the films. These results show a route toward the fabrication of single crystal piezoelectric thin films and devices with high quality, long-lifetime piezoelectric capacitor structures on nonperovskite and even noncrystalline substrates such as glass or polished metal surfaces.

  17. New CVD-based method for the growth of high-quality crystalline zinc oxide layers

    NASA Astrophysics Data System (ADS)

    Huber, Florian; Madel, Manfred; Reiser, Anton; Bauer, Sebastian; Thonke, Klaus

    2016-07-01

    High-quality zinc oxide (ZnO) layers were grown using a new chemical vapour deposition (CVD)-based low-cost growth method. The process is characterized by total simplicity, high growth rates, and cheap, less hazardous precursors. To produce elementary zinc vapour, methane (CH4) is used to reduce a ZnO powder. By re-oxidizing the zinc with pure oxygen, highly crystalline ZnO layers were grown on gallium nitride (GaN) layers and on sapphire substrates with an aluminum nitride (AlN) nucleation layer. Using simple CH4 as precursor has the big advantage of good controllability and the avoidance of highly toxic gases like nitrogen oxides. In photoluminescence (PL) measurements the samples show a strong near-band-edge emission and a sharp line width at 5 K. The good crystal quality has been confirmed in high resolution X-ray diffraction (HRXRD) measurements. This new growth method has great potential for industrial large-scale production of high-quality single crystal ZnO layers.

  18. Statistical modeling of crack growth and reliability assessment of high-density polyethylene

    SciTech Connect

    Qureshi, F.S.; Sheikh, A.K.; Khan, Z.; Ahmad, M.

    1999-06-01

    In this work, a statistical evaluation of the crack-growth process in high-density polyethylene (HDPE) was carried out. The specimens were compression molded from virgin, molding-grade HDPE. Edge-notched specimens for replicate fatigue testing were prepared from compression-molded sheets. Fatigue test results were then analyzed, and it is shown that if the crack-growth process can be characterized as a random process following a power-law-type behavior, then the time to reach a critical crack length will be distributed according to an inverted lognormal model.

  19. High water-use efficiency and growth contribute to success of non-native Erodium cicutarium in a Sonoran Desert winter annual community.

    PubMed

    Kimball, Sarah; Gremer, Jennifer R; Barron-Gafford, Greg A; Angert, Amy L; Huxman, Travis E; Venable, D Lawrence

    2014-01-01

    The success of non-native, invasive species may be due to release from natural enemies, superior competitive abilities, or both. In the Sonoran Desert, Erodium cicutarium has increased in abundance over the last 30 years. While native species in this flora exhibit a strong among-species trade-off between relative growth rate and water-use efficiency, E. cicutarium seems to have a higher relative growth rate for its water-use efficiency value relative to the pattern across native species. This novel trait combination could provide the non-native species with a competitive advantage in this water-limited environment. To test the hypothesis that E. cicutarium is able to achieve high growth rates due to release from native herbivores, we compared the effects of herbivory on E. cicutarium and its native congener, Erodium texanum. We also compared these two species across a range of environmental conditions, both in a common garden and in two distinct seasons in the field, using growth analysis, isotopic compositions and leaf-level gas exchange. Additionally, we compared the competitive abilities of the two Erodium species in a greenhouse experiment. We found no evidence of herbivory to either species. Physiological measurements in a common environment revealed that E. cicutarium was able to achieve high growth rates while simultaneously controlling leaf-level water loss. Non-native E. cicutarium responded to favourable conditions in the field with greater specific leaf area and leaf area ratio than native E. texanum. The non-native Erodium was a stronger competitor than its native congener in a greenhouse competition experiment. The ability to maintain relatively higher values of water-use efficiency:relative growth rate in comparison to the native flora may be what enables E. cictarium to outcompete native species in both wet and dry years, resulting in an increase in abundance in the highly variable Sonoran Desert.

  20. High water-use efficiency and growth contribute to success of non-native Erodium cicutarium in a Sonoran Desert winter annual community

    PubMed Central

    Kimball, Sarah; Gremer, Jennifer R.; Barron-Gafford, Greg A.; Angert, Amy L.; Huxman, Travis E.; Venable, D. Lawrence

    2014-01-01

    The success of non-native, invasive species may be due to release from natural enemies, superior competitive abilities, or both. In the Sonoran Desert, Erodium cicutarium has increased in abundance over the last 30 years. While native species in this flora exhibit a strong among-species trade-off between relative growth rate and water-use efficiency, E. cicutarium seems to have a higher relative growth rate for its water-use efficiency value relative to the pattern across native species. This novel trait combination could provide the non-native species with a competitive advantage in this water-limited environment. To test the hypothesis that E. cicutarium is able to achieve high growth rates due to release from native herbivores, we compared the effects of herbivory on E. cicutarium and its native congener, Erodium texanum. We also compared these two species across a range of environmental conditions, both in a common garden and in two distinct seasons in the field, using growth analysis, isotopic compositions and leaf-level gas exchange. Additionally, we compared the competitive abilities of the two Erodium species in a greenhouse experiment. We found no evidence of herbivory to either species. Physiological measurements in a common environment revealed that E. cicutarium was able to achieve high growth rates while simultaneously controlling leaf-level water loss. Non-native E. cicutarium responded to favourable conditions in the field with greater specific leaf area and leaf area ratio than native E. texanum. The non-native Erodium was a stronger competitor than its native congener in a greenhouse competition experiment. The ability to maintain relatively higher values of water-use efficiency:relative growth rate in comparison to the native flora may be what enables E. cictarium to outcompete native species in both wet and dry years, resulting in an increase in abundance in the highly variable Sonoran Desert. PMID:27293627

  1. Modeling stability of growth between mathematics and science achievement during middle and high school.

    PubMed

    Ma, Xin; Ma, Lingling

    2004-04-01

    In this study, the authors introduced a multivariate multilevel model to estimate the consistency among students and schools in the rates of growth between mathematics and science achievement during the entire middle and high school years with data from the Longitudinal Study of American Youth (LSAY). There was no evident consistency in the rates of growth between mathematics and science achievement among students, and this inconsistency was not much influenced by student characteristics and school characteristics. However, there was evident consistency in the average rates of growth between mathematics and science achievement among schools, and this consistency was influenced by student characteristics and school characteristics. Major school-level variables associated with parental involvement did not show any significant impacts on consistency among either students or schools. Results call for educational policies that promote collaboration between mathematics and science departments or teachers.

  2. Effects of Ni Additions on the Growth of Cu3Sn in High-Lead Solders

    NASA Astrophysics Data System (ADS)

    Wang, Y. W.; Chang, C. C.; Chen, W. M.; Kao, C. R.

    2010-12-01

    In reactions between solders and Cu, additions of minor alloying elements, such as Fe, Co or Ni, to solders often reduce the Cu3Sn growth rate. Nevertheless, the mechanism for this effect remains unresolved. To provide more experimental observations that are essential for uncovering this mechanism, growth of Cu3Sn in the reaction between Cu and high-lead solders with or without Ni additions has been studied. The solders used for this study were 10Sn-90Pb and 5Sn-95Pb doped with 0 wt.%, 0.03 wt.%, 0.06 wt.%, 0.1 wt.% or 0.2 wt.% Ni. Reaction conditions included one reflow at 350°C for 2 min and solid-state aging at 160°C for up to 2000 h. The effect of Ni on the growth of Cu3Sn is discussed in detail based on the experimental results.

  3. Large single crystal growth of MnWO4-type materials from high-temperature solutions

    NASA Astrophysics Data System (ADS)

    Gattermann, U.; Röska, B.; Paulmann, C.; Park, S.-H.

    2016-11-01

    A simple high-temperature growth apparatus was constructed to obtain large crystals of chemically gradient (In, Na)-doped MnWO4solid-solutions. This paper presents the crystal growth and characterisation of both MnWO4and epitaxially grown (In, Na): MnWO4crystals on MnWO4. These large monolithic crystals were made in two steps: A MnWO4 crystal was grown in the crystallographic main direction [001] applying the Czochralski method, followed by the top seeded growth of (In, Na): MnWO4 solid-solutions with an oriented seed crystal of MnWO4. Such a monolithic crystal will serve to fundamental investigation of coupling properties at boundaries between various multiferroic MnWO4-typesolid-solutions.

  4. Compartmentalized microchannel array for high-throughput analysis of single cell polarized growth and dynamics

    PubMed Central

    Geng, Tao; Bredeweg, Erin L.; Szymanski, Craig J.; Liu, Bingwen; Baker, Scott E.; Orr, Galya; Evans, James E.; Kelly, Ryan T.

    2015-01-01

    Interrogating polarized growth is technologically challenging due to extensive cellular branching and uncontrollable environmental conditions in conventional assays. Here we present a robust and high-performance microfluidic system that enables observations of polarized growth with enhanced temporal and spatial control over prolonged periods. The system has built-in tunability and versatility to accommodate a variety of scientific applications requiring precisely controlled environments. Using the model filamentous fungus, Neurospora crassa, our microfluidic system enabled direct visualization and analysis of cellular heterogeneity in a clonal fungal cell population, nuclear distribution and dynamics at the subhyphal level, and quantitative dynamics of gene expression with single hyphal compartment resolution in response to carbon source starvation and exchange. Although the microfluidic device is demonstrated on filamentous fungi, the technology is immediately extensible to a wide array of other biosystems that exhibit similar polarized cell growth, with applications ranging from bioenergy production to human health. PMID:26530004

  5. Crystal growth of high magnetostrictive polycrystalline Fe 81Ga 19 alloys

    NASA Astrophysics Data System (ADS)

    Li, Chuan; Liu, Jinghua; Wang, Zhibin; Jiang, Chengbao

    2012-03-01

    High magnetostrictive Fe81Ga19 alloy was prepared by induction heating zone melting method. The microstructure, solute partition behaviour, orientation evolution and magnetostriction are investigated. During the crystal growth process, the initial small grains gradually grow into large columnar crystals, and the solid-liquid interface shows slightly concave morphology. The equilibrium solute partition coefficient (k0), effective solute partition coefficient (ke) and solution diffusion coefficient (D) are calculated to be 0.74, 0.76 and 1.04×10-9 m2/s, respectively. In the steady growth stage, the composition distribution of the FeGa rod is uniform with average level about 18.50 at% Ga, which is close to the nominal composition. The deviation of the <001> orientation from the axial direction evolves from about 8° to 3° along the growth direction, and the corresponding magnetostriction increases from the initial 180 ppm to the final 305 ppm.

  6. Thin film growth of the 2122-phase of BCSCO superconductor with high degree of crystalline perfection

    NASA Technical Reports Server (NTRS)

    Raina, K. K.; Narayanan, S.; Pandey, R. K.

    1992-01-01

    Thin films of the 80 K-phase of BiCaSrCu-oxide superconductor having the composition of Bi2Ca1.05Sr2.1Cu2.19O(x) and high degree of crystalline perfection have been grown on c-axis oriented twin free single crystal substrates of NdGaO3. This has been achieved by carefully establishing the growth conditions of the LPE experiments. The temperature regime of 850 to 830 C and quenching of the specimens on the termination of the growth period are found to be pertinent for the growth of quasi-single crystalline superconducting BCSCO films on NdGaO3 substrates. The TEM analysis reveals a single crystalline nature of these films which exhibit 100 percent reflectivity in infrared regions at liquid nitrogen temperature.

  7. Mapping high-growth phenotypes in the flux space of microbial metabolism

    PubMed Central

    Güell, Oriol; Massucci, Francesco Alessandro; Font-Clos, Francesc; Sagués, Francesc; Serrano, M. Ángeles

    2015-01-01

    Experimental and empirical observations on cell metabolism cannot be understood as a whole without their integration into a consistent systematic framework. However, the characterization of metabolic flux phenotypes is typically reduced to the study of a single optimal state, such as maximum biomass yield that is by far the most common assumption. Here, we confront optimal growth solutions to the whole set of feasible flux phenotypes (FFPs), which provides a benchmark to assess the likelihood of optimal and high-growth states and their agreement with experimental results. In addition, FFP maps are able to uncover metabolic behaviours, such as aerobic fermentation accompanying exponential growth on sugars at nutrient excess conditions, that are unreachable using standard models based on optimality principles. The information content of the full FFP space provides us with a map to explore and evaluate metabolic behaviour and capabilities, and so it opens new avenues for biotechnological and biomedical applications. PMID:26289659

  8. Compartmentalized microchannel array for high-throughput analysis of single cell polarized growth and dynamics

    DOE PAGES

    Geng, Tao; Bredeweg, Erin L.; Szymanski, Craig J.; ...

    2015-11-04

    Here, interrogating polarized growth is technologically challenging due to extensive cellular branching and uncontrollable environmental conditions in conventional assays. Here we present a robust and high-performance microfluidic system that enables observations of polarized growth with enhanced temporal and spatial control over prolonged periods. The system has built-in tunability and versatility to accommodate a variety of science applications requiring precisely controlled environments. Using the model filamentous fungus, Neurospora crassa, this microfluidic system enabled direct visualization and analysis of cellular heterogeneity in a clonal fungal cell population, nuclear distribution and dynamics at the subhyphal level, and quantitative dynamics of gene expression withmore » single hyphal compartment resolution in response to carbon source starvation and exchange experiments. Although the microfluidic device is demonstrated on filamentous fungi, our technology is immediately extensible to a wide array of other biosystems that exhibit similar polarized cell growth with applications ranging from bioenergy production to human health.« less

  9. Compartmentalized microchannel array for high-throughput analysis of single cell polarized growth and dynamics

    SciTech Connect

    Geng, Tao; Bredeweg, Erin L.; Szymanski, Craig J.; Liu, Bingwen; Baker, Scott E.; Orr, Galya; Evans, James E.; Kelly, Ryan T.

    2015-11-04

    Here, interrogating polarized growth is technologically challenging due to extensive cellular branching and uncontrollable environmental conditions in conventional assays. Here we present a robust and high-performance microfluidic system that enables observations of polarized growth with enhanced temporal and spatial control over prolonged periods. The system has built-in tunability and versatility to accommodate a variety of science applications requiring precisely controlled environments. Using the model filamentous fungus, Neurospora crassa, this microfluidic system enabled direct visualization and analysis of cellular heterogeneity in a clonal fungal cell population, nuclear distribution and dynamics at the subhyphal level, and quantitative dynamics of gene expression with single hyphal compartment resolution in response to carbon source starvation and exchange experiments. Although the microfluidic device is demonstrated on filamentous fungi, our technology is immediately extensible to a wide array of other biosystems that exhibit similar polarized cell growth with applications ranging from bioenergy production to human health.

  10. Growth of high quality and uniformity AlGaN/GaN heterostructures on Si substrates using a single AlGaN layer with low Al composition

    NASA Astrophysics Data System (ADS)

    Cheng, Jianpeng; Yang, Xuelin; Sang, Ling; Guo, Lei; Zhang, Jie; Wang, Jiaming; He, Chenguang; Zhang, Lisheng; Wang, Maojun; Xu, Fujun; Tang, Ning; Qin, Zhixin; Wang, Xinqiang; Shen, Bo

    2016-03-01

    By employing a single AlGaN layer with low Al composition, high quality and uniformity AlGaN/GaN heterostructures have been successfully grown on Si substrates by metal-organic chemical vapor deposition (MOCVD). The heterostructures exhibit a high electron mobility of 2150 cm2/Vs with an electron density of 9.3 × 1012 cm‑2. The sheet resistance is 313 ± 4 Ω/◻ with ±1.3% variation. The high uniformity is attributed to the reduced wafer bow resulting from the balance of the compressive stress induced and consumed during the growth, and the thermal tensile stress induced during the cooling down process. By a combination of theoretical calculations and in situ wafer curvature measurements, we find that the compressive stress consumed by the dislocation relaxation (~1.2 GPa) is comparable to the value of the thermal tensile stress (~1.4 GPa) and we should pay more attention to it during growth of GaN on Si substrates. Our results demonstrate a promising approach to simplifying the growth processes of GaN-on-Si to reduce the wafer bow and lower the cost while maintaining high material quality.

  11. Growth of high quality and uniformity AlGaN/GaN heterostructures on Si substrates using a single AlGaN layer with low Al composition

    PubMed Central

    Cheng, Jianpeng; Yang, Xuelin; Sang, Ling; Guo, Lei; Zhang, Jie; Wang, Jiaming; He, Chenguang; Zhang, Lisheng; Wang, Maojun; Xu, Fujun; Tang, Ning; Qin, Zhixin; Wang, Xinqiang; Shen, Bo

    2016-01-01

    By employing a single AlGaN layer with low Al composition, high quality and uniformity AlGaN/GaN heterostructures have been successfully grown on Si substrates by metal-organic chemical vapor deposition (MOCVD). The heterostructures exhibit a high electron mobility of 2150 cm2/Vs with an electron density of 9.3 × 1012 cm−2. The sheet resistance is 313 ± 4 Ω/◻ with ±1.3% variation. The high uniformity is attributed to the reduced wafer bow resulting from the balance of the compressive stress induced and consumed during the growth, and the thermal tensile stress induced during the cooling down process. By a combination of theoretical calculations and in situ wafer curvature measurements, we find that the compressive stress consumed by the dislocation relaxation (~1.2 GPa) is comparable to the value of the thermal tensile stress (~1.4 GPa) and we should pay more attention to it during growth of GaN on Si substrates. Our results demonstrate a promising approach to simplifying the growth processes of GaN-on-Si to reduce the wafer bow and lower the cost while maintaining high material quality. PMID:26960730

  12. Subcritical Crack Growth in Ceramic Composites at High Temperature Measured Using Digital Image Correlation

    SciTech Connect

    Mumm, D.R.; Morris, W.L.; Dadkhah, M.S.; Cox, B.N.

    1996-01-11

    An in situ experimental technique is described that allows high resolution, high sensitivity determination of displacements and full-field strains during high temperature mechanical testing. The technique is used to investigate elevated temperature crack growth in SiC/Nicalon sub f composites. At 1150 degrees C, the reinforcing fibers have a higher creep susceptibility than the matrix. Fiber creep leads to relaxation of crack bridging tractions, resulting in subcritical crack growth. Differential image analysis is used to measure the crack opening displacement profile u(x) of an advancing, bridged crack. With appropriate modeling, such data can be used to determine the traction law, from which the mechanics of cracking and failure may be determined.

  13. Basic criteria for formation of growth twins in high stacking fault energy metals

    NASA Astrophysics Data System (ADS)

    Yu, K. Y.; Bufford, D.; Chen, Y.; Liu, Y.; Wang, H.; Zhang, X.

    2013-10-01

    Nanotwinned metals received significant interest lately as twin boundaries may enable simultaneous enhancement of strength, ductility, thermal stability, and radiation tolerance. However, nanotwins have been the privilege of metals with low-to-intermediate stacking fault energy (SFE). Recent scattered studies show that nanotwins could be introduced into high SFE metals, such as Al. In this paper, we examine several sputter-deposited, {111} textured Ag/Al, Cu/Ni, and Cu/Fe multilayers, wherein growth twins were observed in Al, Ni, and face-centered cubic (fcc) Fe. The comparisons lead to two important design criteria that dictate the introduction of growth twins in high SFE metals. The validity of these criteria was then examined in Ag/Ni multilayers. Furthermore, another twin formation mechanism in high SFE metals was discovered in Ag/Ni system.

  14. Basic criteria for formation of growth twins in high stacking fault energy metals

    SciTech Connect

    Yu, K. Y.; Zhang, X.; Bufford, D.; Chen, Y.; Liu, Y.; Wang, H.

    2013-10-28

    Nanotwinned metals received significant interest lately as twin boundaries may enable simultaneous enhancement of strength, ductility, thermal stability, and radiation tolerance. However, nanotwins have been the privilege of metals with low-to-intermediate stacking fault energy (SFE). Recent scattered studies show that nanotwins could be introduced into high SFE metals, such as Al. In this paper, we examine several sputter-deposited, (111) textured Ag/Al, Cu/Ni, and Cu/Fe multilayers, wherein growth twins were observed in Al, Ni, and face-centered cubic (fcc) Fe. The comparisons lead to two important design criteria that dictate the introduction of growth twins in high SFE metals. The validity of these criteria was then examined in Ag/Ni multilayers. Furthermore, another twin formation mechanism in high SFE metals was discovered in Ag/Ni system.

  15. Antimony mediated growth of high-density InAs quantum dots for photovoltaic cells

    SciTech Connect

    Tutu, F. K.; Wu, J.; Lam, P.; Tang, M.; Liu, H.; Miyashita, N.; Okada, Y.; Wilson, J.; Allison, R.

    2013-07-22

    We report enhanced solar cell performance using high-density InAs quantum dots. The high-density quantum dot was grown by antimony mediated molecular beam epitaxy. In-plane quantum dot density over 1 × 10{sup 11} cm{sup −2} was achieved by applying a few monolayers of antimony on the GaAs surface prior to quantum dot growth. The formation of defective large clusters was reduced by optimization of the growth temperature and InAs coverage. Comparing with a standard quantum dot solar cell without the incorporation of antimony, the high-density quantum dot solar cell demonstrates a distinct improvement in short-circuit current from 7.4 mA/cm{sup 2} to 8.3 mA/cm{sup 2}.

  16. Growth of Preschool Children at High Risk for Asthma Two Years after Discontinuation of Fluticasone

    PubMed Central

    Guilbert, Theresa W.; Mauger, David T.; Allen, David B.; Zeiger, Robert S.; Lemanske, Robert F.; Szefler, Stanley J.; Strunk, Robert C.; Bacharier, Leonard B.; Covar, Ronina; Sorkness, Christine A.; Taussig, Lynn M.; Martinez, Fernando D.

    2011-01-01

    Background The effect on linear growth of daily long-term inhaled corticosteroid (ICS) therapy in preschool-aged children with recurrent wheezing is controversial. Objective To determine the effect of daily ICS given for 2 years on linear growth in preschool children with recurrent wheezing. Methods Children ages 2 and 3 years with recurrent wheezing and positive modified asthma predictive indices were randomized to a two-year treatment period of fluticasone propionate CFC (176 mcg/day) or masked-placebo delivered by valved chamber with mask and then followed 2 years off study medication. Height growth determined by stadiometry was compared between treatment groups. Results In the study cohort as a whole, the fluticasone group did not have significantly less linear growth than the placebo-group [change in height from baseline difference (ΔHt) of −0.2 cm (95% CI, −1.1, 0.6)] two years after discontinuation of study treatment. In post-hoc analyses, children 2 years old and who weighed < 15 kg at enrollment treated with fluticasone had less linear growth compared to placebo [ΔHt of −1.6 cm (95% CI, −2.8, −0.4), p=0.009]. Conclusion Linear growth was not significantly different in high-risk, recurrent wheezing preschool age children treated with CFC fluticasone 176 mcg/day compared to placebo 2 years after fluticasone is discontinued. However, post-hoc subgroup analyses revealed that children who are younger in age and of lesser weight relative to the entire study cohort had significantly less linear growth, possibly due to a higher relative fluticasone exposure. PMID:21820163

  17. Growth of preschool children at high risk for asthma 2 years after discontinuation of fluticasone.

    PubMed

    Guilbert, Theresa W; Mauger, David T; Allen, David B; Zeiger, Robert S; Lemanske, Robert F; Szefler, Stanley J; Strunk, Robert C; Bacharier, Leonard B; Covar, Ronina; Sorkness, Christine A; Taussig, Lynn M; Martinez, Fernando D

    2011-11-01

    The effect on linear growth of daily long-term inhaled corticosteroid therapy in preschool-aged children with recurrent wheezing is controversial. We sought to determine the effect of daily inhaled corticosteroid given for 2 years on linear growth in preschool children with recurrent wheezing. Children aged 2 and 3 years with recurrent wheezing and positive modified Asthma Predictive Index scores were randomized to a 2-year treatment period of chlorofluorocarbon-delivered fluticasone propionate (176 μg/d) or masked placebo delivered through a valved chamber with a mask and then followed for 2 years off study medication. Height growth determined by means of stadiometry was compared between treatment groups. In the study cohort as a whole, the fluticasone group did not have significantly less linear growth than the placebo group (change in height from baseline difference, -0.2 cm; 95% CI, -1.1 to 0.6) 2 years after discontinuation of study treatment. In post hoc analyses children 2 years old who weighed less than 15 kg at enrollment and were treated with fluticasone had less linear growth compared with those treated with placebo (change in height from baseline difference, -1.6 cm; 95% CI, -2.8 to -0.4; P = .009). Linear growth was not significantly different in high-risk preschool-aged children with recurrent wheezing treated with 176 μg/d chlorofluorocarbon-delivered fluticasone compared with placebo 2 years after fluticasone is discontinued. However, post hoc subgroup analyses revealed that children who are younger in age and of lesser weight relative to the entire study cohort had significantly less linear growth, possibly because of a higher relative fluticasone exposure. Copyright © 2011 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

  18. Patterned growth of carbon nanotubes obtained by high density plasma chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Mousinho, A. P.; Mansano, R. D.

    2015-03-01

    Patterned growth of carbon nanotubes by chemical vapor deposition represents an assembly approach to place and orient nanotubes at a stage as early as when they are synthesized. In this work, the carbon nanotubes were obtained at room temperature by High Density Plasmas Chemical Vapor Deposition (HDPCVD) system. This CVD system uses a new concept of plasma generation, where a planar coil coupled to an RF system for plasma generation was used with an electrostatic shield for plasma densification. In this mode, high density plasmas are obtained. We also report the patterned growth of carbon nanotubes on full 4-in Si wafers, using pure methane plasmas and iron as precursor material (seed). Photolithography processes were used to pattern the regions on the silicon wafers. The carbon nanotubes were characterized by micro-Raman spectroscopy, the spectra showed very single-walled carbon nanotubes axial vibration modes around 1590 cm-1 and radial breathing modes (RBM) around 120-400 cm-1, confirming that high quality of the carbon nanotubes obtained in this work. The carbon nanotubes were analyzed by atomic force microscopy and scanning electron microscopy too. The results showed that is possible obtain high-aligned carbon nanotubes with patterned growth on a silicon wafer with high reproducibility and control.

  19. A marker of growth differs between adolescents with high versus low sugar preference

    PubMed Central

    Coldwell, Susan E.; Oswald, Teresa K.; Reed, Danielle R.

    2009-01-01

    Sweet preference is higher in childhood than adulthood but the mechanism for this developmental shift is not known. The objective of this study was to assess perceptual, physiological and eating habit differences between children preferring solutions high in sugar (high preference) and children preferring solutions low in sugar (low preference). We tested 143 children (11- to 15-years old) using sip and spit methodology to assess their hedonic profile, detection threshold, and perceived intensity of sucrose. Their plasma concentration of several hormones, a biomarker of bone-growth, body size, puberty stage, and dietary habits were measured. Eighty-eight children were classified as high preference and 53 were classified as low preference based on their hedonic ratings to a series of sucrose solutions. A marker of bone growth measured in urine and plasma leptin adjusted for body weight were significantly lower in the low preference group. Children with high and low preference patterns did not differ in sensory aspects of sucrose perception, nor did they differ in age, body mass index percentile, or dietary restraint. The change in sugar preference from high to low during adolescence appears to be associated with the cessation of growth. PMID:19150454

  20. Tree seedling growth enhancement in a high CO[sub 2] environment declines over three years

    SciTech Connect

    Miao, S.L.; Bazzaz, F.A. )

    1993-06-01

    For predicting global carbon budgets in a high CO[sub 2] environment of the future, we must understand how long the enhancement of plant growth in the high CO[sub 2] environment will be sustained. To elucidate how an enriched CO[sub 2] atmosphere affects long-term growth of tree seedlings, we grew ash (Fraxinus americana L.), gray birch (Betula populifolia), red maple (Acer rubrum), yellow birch (Betula alleghaniensis), striped maple (Acer pensylvanicum), and red oak (Quercus rubra L.) seedlings in various combinations of light, nutrient, and CO[sub 2] levels for three years. After year one, in 10 of 24 cases plants grown in high CO[sub 2] were significantly larger than those grown in ambient CO[sub 2], however, after three years only 6 of 24 cases differed significantly. Weight ratio (die ratio of total weight of plants grown in high CO[sub 2] to that of plants grown in ambient CO[sub 2]) declined from year one to year dime for plants grown in high nutrient and low light. Species identity determined whether weight ratio decreased, increased, or remained unchanged in the other dime treatments. Allocation patterns were largely unaffected by CO[sub 2], but significantly affected by nutrients and light in most species. These insults suggest that the stimulation of seedling growth in response to elevated CO[sub 2] for some species may be of a limited duration and depends on the levels of other resources in the environment.

  1. The lag-phase during diauxic growth is a trade-off between fast adaptation and high growth rate

    NASA Astrophysics Data System (ADS)

    Chu, Dominique; Barnes, David J.

    2016-04-01

    Bi-phasic or diauxic growth is often observed when microbes are grown in a chemically defined medium containing two sugars (for example glucose and lactose). Typically, the two growth stages are separated by an often lengthy phase of arrested growth, the so-called lag-phase. Diauxic growth is usually interpreted as an adaptation to maximise population growth in multi-nutrient environments. However, the lag-phase implies a substantial loss of growth during the switch-over. It therefore remains unexplained why the lag-phase is adaptive. Here we show by means of a stochastic simulation model based on the bacterial PTS system that it is not possible to shorten the lag-phase without incurring a permanent growth-penalty. Mechanistically, this is due to the inherent and well established limitations of biological sensors to operate efficiently at a given resource cost. Hence, there is a trade-off between lost growth during the diauxic switch and the long-term growth potential of the cell. Using simulated evolution we predict that the lag-phase will evolve depending on the distribution of conditions experienced during adaptation. In environments where switching is less frequently required, the lag-phase will evolve to be longer whereas, in frequently changing environments, the lag-phase will evolve to be shorter.

  2. Highly Invasive Listeria monocytogenes Strains Have Growth and Invasion Advantages in Strain Competition

    PubMed Central

    Manthou, Evanthia; Ciolacu, Luminita; Wagner, Martin; Skandamis, Panagiotis N.

    2015-01-01

    Multiple Listeria monocytogenes strains can be present in the same food sample; moreover, infection with more than one L. monocytogenes strain can also occur. In this study we investigated the impact of strain competition on the growth and in vitro virulence potential of L. monocytogenes. We identified two strong competitor strains, whose growth was not (or only slightly) influenced by the presence of other strains and two weak competitor strains, which were outcompeted by other strains. Cell contact was essential for growth inhibition. In vitro virulence assays using human intestinal epithelial Caco2 cells showed a correlation between the invasion efficiency and growth inhibition: the strong growth competitor strains showed high invasiveness. Moreover, invasion efficiency of the highly invasive strain was further increased in certain combinations by the presence of a low invasive strain. In all tested combinations, the less invasive strain was outcompeted by the higher invasive strain. Studying the effect of cell contact on in vitro virulence competition revealed a complex pattern in which the observed effects depended only partially on cell-contact suggesting that competition occurs at two different levels: i) during co-cultivation prior to infection, which might influence the expression of virulence factors, and ii) during infection, when bacterial cells compete for the host cell. In conclusion, we show that growth of L. monocytogenes can be inhibited by strains of the same species leading potentially to biased recovery during enrichment procedures. Furthermore, the presence of