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Sample records for cam photosynthesis clusia

  1. Facultative crassulacean acid metabolism (CAM) plants: powerful tools for unravelling the functional elements of CAM photosynthesis.

    Science.gov (United States)

    Winter, Klaus; Holtum, Joseph A M

    2014-07-01

    Facultative crassulacean acid metabolism (CAM) describes the optional use of CAM photosynthesis, typically under conditions of drought stress, in plants that otherwise employ C3 or C4 photosynthesis. In its cleanest form, the upregulation of CAM is fully reversible upon removal of stress. Reversibility distinguishes facultative CAM from ontogenetically programmed unidirectional C3-to-CAM shifts inherent in constitutive CAM plants. Using mainly measurements of 24h CO2 exchange, defining features of facultative CAM are highlighted in five terrestrial species, Clusia pratensis, Calandrinia polyandra, Mesembryanthemum crystallinum, Portulaca oleracea and Talinum triangulare. For these, we provide detailed chronologies of the shifts between photosynthetic modes and comment on their usefulness as experimental systems. Photosynthetic flexibility is also reviewed in an aquatic CAM plant, Isoetes howellii. Through comparisons of C3 and CAM states in facultative CAM species, many fundamental biochemical principles of the CAM pathway have been uncovered. Facultative CAM species will be of even greater relevance now that new sequencing technologies facilitate the mapping of genomes and tracking of the expression patterns of multiple genes. These technologies and facultative CAM systems, when joined, are expected to contribute in a major way towards our goal of understanding the essence of CAM. PMID:24642847

  2. CAM Photosynthesis in Submerged Aquatic Plants

    Science.gov (United States)

    Keeley, J.E.

    1998-01-01

    Crassulacean acid metabolism (CAM) is a CO2-concentrating mechanism selected in response to aridity in terrestrial habitats, and, in aquatic environments, to ambient limitations of carbon. Evidence is reviewed for its presence in five genera of aquatic vascular plants, including Isoe??tes, Sagittaria, Vallisneria, Crassula, and Littorella. Initially, aquatic CAM was considered by some to be an oxymoron, but some aquatic species have been studied in sufficient detail to say definitively that they possess CAM photosynthesis. CO2-concentrating mechanisms in photosynthetic organs require a barrier to leakage; e.g., terrestrial C4 plants have suberized bundle sheath cells and terrestrial CAM plants high stomatal resistance. In aquatic CAM plants the primary barrier to CO2 leakage is the extremely high diffusional resistance of water. This, coupled with the sink provided by extensive intercellular gas space, generates daytime CO2(Pi) comparable to terrestrial CAM plants. CAM contributes to the carbon budget by both net carbon gain and carbon recycling, and the magnitude of each is environmentally influenced. Aquatic CAM plants inhabit sites where photosynthesis is potentially limited by carbon. Many occupy moderately fertile shallow temporary pools that experience extreme diel fluctuations in carbon availability. CAM plants are able to take advantage of elevated nighttime CO2 levels in these habitats. This gives them a competitive advantage over non-CAM species that are carbon starved during the day and an advantage over species that expend energy in membrane transport of bicarbonate. Some aquatic CAM plants are distributed in highly infertile lakes, where extreme carbon limitation and light are important selective factors. Compilation of reports on diel changes in titratable acidity and malate show 69 out of 180 species have significant overnight accumulation, although evidence is presented discounting CAM in some. It is concluded that similar proportions of the aquatic

  3. The pineapple genome and the evolution of CAM photosynthesis

    Science.gov (United States)

    Ming, Ray; VanBuren, Robert; Wai, Ching Man; Tang, Haibao; Schatz, Michael C.; Bowers, John E.; Lyons, Eric; Wang, Ming-Li; Chen, Jung; Biggers, Eric; Zhang, Jisen; Huang, Lixian; Zhang, Lingmao; Miao, Wenjing; Zhang, Jian; Ye, Zhangyao; Miao, Chenyong; Lin, Zhicong; Wang, Hao; Zhou, Hongye; Yim, Won C.; Priest, Henry D.; Zheng, Chunfang; Woodhouse, Margaret; Edger, Patrick P.; Guyot, Romain; Guo, Hao-Bo; Guo, Hong; Zheng, Guangyong; Singh, Ratnesh; Sharma, Anupma; Min, Xiangjia; Zheng, Yun; Lee, Hayan; Gurtowski, James; Sedlazeck, Fritz J.; Harkess, Alex; McKain, Michael R.; Liao, Zhenyang; Fang, Jingping; Liu, Juan; Zhang, Xiaodan; Zhang, Qing; Hu, Weichang; Qin, Yuan; Wang, Kai; Chen, Li-Yu; Shirley, Neil; Lin, Yann-Rong; Liu, Li-Yu; Hernandez, Alvaro G.; Wright, Chris L.; Bulone, Vincent; Tuskan, Gerald A.; Heath, Katy; Zee, Francis; Moore, Paul H.; Sunkar, Ramanjulu; Leebens-Mack, James H.; Mockler, Todd; Bennetzen, Jeffrey L.; Freeling, Michael; Sankoff, David; Paterson, Andrew H.; Zhu, Xinguang; Yang, Xiaohan; Smith, J. Andrew C.; Cushman, John C.; Paull, Robert E.; Yu, Qingyi

    2016-01-01

    Pineapple (Ananas comosus (L.) Merr.) is the most economically valuable crop possessing crassulacean acid metabolism (CAM), a photosynthetic carbon assimilation pathway with high water use efficiency, and the second most important tropical fruit after banana in terms of international trade. We sequenced the genomes of pineapple varieties ‘F153’ and ‘MD2’, and a wild pineapple relative A. bracteatus accession CB5. The pineapple genome has one fewer ancient whole genome duplications than sequenced grass genomes and, therefore, provides an important reference for elucidating gene content and structure in the last common ancestor of extant members of the grass family (Poaceae). Pineapple has a conserved karyotype with seven pre rho duplication chromosomes that are ancestral to extant grass karyotypes. The pineapple lineage has transitioned from C3 photosynthesis to CAM with CAM-related genes exhibiting a diel expression pattern in photosynthetic tissues using beta-carbonic anhydrase (βCA) for initial capture of CO2. Promoter regions of all three βCA genes contain a CCA1 binding site that can bind circadian core oscillators. CAM pathway genes were enriched with cis-regulatory elements including the morning (CCACAC) and evening (AAAATATC) elements associated with regulation of circadian-clock genes, providing the first link between CAM and the circadian clock regulation. Gene-interaction network analysis revealed both activation and repression of regulatory elements that control key enzymes in CAM photosynthesis, indicating that CAM evolved by reconfiguration of pathways preexisting in C3 plants. Pineapple CAM photosynthesis is the result of regulatory neofunctionalization of preexisting gene copies and not acquisition of neofunctionalized genes via whole genome or tandem gene duplication. PMID:26523774

  4. Aquatic CAM photosynthesis: a brief history of its discovery

    Science.gov (United States)

    Keeley, Jon E.

    2014-01-01

    Aquatic CAM (Crassulacean Acid Metabolism) photosynthesis was discovered while investigating an unrelated biochemical pathway concerned with anaerobic metabolism. George Bowes was a significant contributor to this project early in its infancy. Not only did he provide me with some valuable perspectives on peer review rejections, but by working with his gas exchange system I was able to take our initial observations of diel fluctuations in malic acid to the next level, showing this aquatic plant exhibited dark CO2 uptake. CAM is universal in all aquatic species of the worldwide Lycophyta genus Isoetes and non-existent in terrestrial Isoetes. Outside of this genus aquatic CAM has a limited occurrence in three other families, including the Crassulaceae. This discovery led to fascinating adventures in the highlands of the Peruvian Andes in search of Stylites, a terrestrial relative of Isoetes. Stylites is a plant that is hermetically sealed from the atmosphere and obtains all of its carbon from terrestrial sources and recycles carbon through CAM. Considering the Mesozoic origin of Isoetes in shallow pools, coupled with the fact that aquatic Isoetes universally possess CAM, suggests the earliest evolution of CAM photosynthesis was most likely not in terrestrial plants.

  5. The pineapple genome and the evolution of CAM photosynthesis

    Science.gov (United States)

    Pineapple (Ananas comosus (L.) Merr.) is the most economically valuable crop possessing crassulacean acid metabolism (CAM), a photosynthetic carbon assimilation pathway with high water-use efficiency, and the second most important tropical fruit. We sequenced the genomes of pineapple varieties F153 ...

  6. Ecophysiological comportment of the tropical C3/CAM-intermediate tree Clusia rosea in the field as assessed by analysis of stable carbon- and hydrogen-isotope ratios

    International Nuclear Information System (INIS)

    Grown-up trees of C. rosea (girths larger than 7 cm, heights taller than 2 m) in the Virgin Islands have a strong component of nocturnal CAM-type CO2 fixation as indicated by their δ13C values of ≈ −18‰ reaching up to the low end of the range typical for CAM (−9 to −18‰). Seedlings (girths up to 3.5em and heights up to 1.2m) have a smaller but still notable CO2-dark fixation as suggested by ODC values of ≈ −21 to ≈ −26‰, and only very small seedlings appear to be exclusively C3 (δ13C = −29‰). The larger variation of δ13C-values among seedlings suggests that seedlings make more flexible use of the options of CO2 dark- and light-fixation than adult trees, while the larger variation of δD-values among trees supports the conclusion, that overall the trees are more flexible in their use of water in transpiration. More negative values of δ13C and δD in terrestrial plants as compared to their epiphytic sympatriotes suggest that the ratio of dark fixation to light fixation of CO2 is smaller in terrestrial plants and that epiphytic plants transpire more of the water available to them. Leaf-N levels support the assumption of a better supply of the terrestrial plants. The analyses of stable isotopes and leaf-N levels, which are very suitable for screening in the field, corroborate the high ecophysiological flexibility of C. rosea as shown by more elaborate experimental approaches in the laboratory and in the field. (author)

  7. Large-scale mRNA expression profiling in the common ice plant, Mesembryanthemum crystallinum, performing C3 photosynthesis and Crassulacean acid metabolism (CAM).

    Science.gov (United States)

    Cushman, John C; Tillett, Richard L; Wood, Joshua A; Branco, Joshua M; Schlauch, Karen A

    2008-01-01

    The common ice plant (Mesembryanthemum crystallinum L.) has emerged as a useful model for molecular genetic studies of Crassulacean acid metabolism (CAM) because CAM can be induced in this species by water deficit or salinity stress. Non-redundant sequence information from expressed sequence tag data was used to fabricate a custom oligonucleotide microarray to compare large-scale mRNA expression patterns in M. crystallinum plants conducting C(3) photosynthesis versus CAM. Samples were collected every 4 h over a 24 h time period at the start of the subjective second day from plants grown under constant light and temperature conditions in order to capture variation in mRNA expression due to salinity stress and circadian clock control. Of 8455 genes, a total of 2343 genes (approximately 28%) showed a significant change as judged by analysis of variance (ANOVA) in steady-state mRNA abundance at one or more time points over the 24 h period. Of these, 858 (10%) and 599 (7%) exhibited a greater than two-fold ratio (TFR) increase or decrease in mRNA abundance, respectively. Functional categorization of these TFR genes revealed that many genes encoding products that function in CAM-related C(4) acid carboxylation/decarboxylation, glycolysis/gluconeogenesis, polysaccharide, polyol, and starch biosynthesis/degradation, protein degradation, transcriptional activation, signalling, stress response, and transport facilitation, and novel, unclassified proteins exhibited stress-induced increases in mRNA abundance. In contrast, salt stress resulted in a significant decrease in transcript abundance for genes encoding photosynthetic functions, protein synthesis, and cellular biogenesis functions. Many genes with CAM-related functions exhibited phase shifts in their putative circadian expression patterns following CAM induction. This report establishes an extensive catalogue of gene expression patterns for future investigations aimed at understanding the complex, transcriptional

  8. Bees visitors of three species of Clusia (Clusiaceae) flowers in Central Amazonia Abelhas visitantes de flores de três espécies de Clusia (Clusiacea) na Amazônia Central

    OpenAIRE

    Ana Claudia Kaminski; Maria Lúcia Absy

    2006-01-01

    Observations on bees visitors to three species of Clusia (Clusiaceae) flowers in the Reserva Adolpho Ducke, Manaus, Amazonas, Brazil were made during three two-week periods. The three species of Clusia, namely C. grandiflora, C. panapanari and C. insignis, presented variations regarding the species of bee visitors. A total of 23 bee species visited the three species of Clusia. The Euglossini and Meliponinae bees were the most frequent visitors of the Clusia flowers. Bee collecting behavior of...

  9. A New Xeromorphic Species of Clusia (Clusiaceae) from Dry Valleys of Northern Peru

    DEFF Research Database (Denmark)

    Gustafsson, Mats

    2010-01-01

    Clusia magnoliiflora M. H. G. Gust. is described as new for the Clusiaceae. It grows in dry scrub in the river valleys of the Marañón and its tributaries in northern Peru, a kind of habitat that harbors very few Clusia species. The species is distinct on account of its extremely thick, obovate...

  10. Bees visitors of three species of Clusia (Clusiaceae flowers in Central Amazonia Abelhas visitantes de flores de três espécies de Clusia (Clusiacea na Amazônia Central

    Directory of Open Access Journals (Sweden)

    Ana Claudia Kaminski

    2006-01-01

    Full Text Available Observations on bees visitors to three species of Clusia (Clusiaceae flowers in the Reserva Adolpho Ducke, Manaus, Amazonas, Brazil were made during three two-week periods. The three species of Clusia, namely C. grandiflora, C. panapanari and C. insignis, presented variations regarding the species of bee visitors. A total of 23 bee species visited the three species of Clusia. The Euglossini and Meliponinae bees were the most frequent visitors of the Clusia flowers. Bee collecting behavior of floral resources is described.Durante seis semanas foram realizadas observações das abelhas visitantes de flores de três espécies de Clusia (Clusiaceae, na Reserva Florestal Adolpho Ducke, em Manaus. As três espécies de Clusia: C. grandiflora Splitg., C. panapanari (Aubl. e C. insignis Mart. apresentaram diferenças com relação às visitas de espécies de abelhas, tendo sido visitadas por 23 espécies. Abelhas Euglossini e Meliponinae foram os visitantes mais freqüentes em flores de Clusia. O comportamento de coleta de recursos florais é descrito.

  11. Dioecious Clusia nemorosa achieves pollination by combining specialized and generalized floral rewards

    Czech Academy of Sciences Publication Activity Database

    Vlasáková, Blanka; Jarau, S.

    2011-01-01

    Roč. 212, č. 8 (2011), s. 1327-1337. ISSN 1385-0237 R&D Projects: GA ČR(CZ) GD206/03/H137 Institutional research plan: CEZ:AV0Z60050516 Keywords : Clusia * inselberg * Meliponini Subject RIV: EF - Botanics Impact factor: 1.829, year: 2011

  12. A new biphenyl from Clusia melchiorii and a new tocotrienol from C. obdeltifolia

    Energy Technology Data Exchange (ETDEWEB)

    Teixeira, Josanaide S.R.; Moreira, Luciana de M.; Cruz, Frederico G. [Bahia Univ., Salvador, BA (Brazil). Inst. de Quimica]. E-mail: fguare@ufba.br; Guedes, Maria L. da S. [Bahia Univ., Salvador, BA (Brazil). Inst. de Biologia

    2006-08-15

    Chromatographic purification of the dichloromethane extract of Clusia melchiorii trunk leading to the isolation of a new biphenyl, 2,2-dimethyl-5-hydroxy-7-phenylchromene, along with the known compounds 2,2-dimethyl-5,10-dihydro-2H-benzo[g]chromene-5,10-dione (xyloidone), betulinic acid, friedelin, friedelinol, euphol, sitostenone, stigmastenone and a mixture of {beta}-sitosterol and stigmasterol. The hexane extract of Clusia obdeltifolia trunk yielded, after chromatographic fractionation, a new {delta}-tocotrienilic alcohol 2Z, 6E, 10E-13-(6-hydroxy- 2,8-dimethyl-3,4-dihydro-2H,2-chromenyl)-2,6,10-trimethyl- 2,6,10-tridecatrien-1-ol, along with 2Z and 2E-{delta}-tocotrienoloic acids, betulinic acid, betulonic acid, betunilic aldehyde, glutinol, friedelin, sitostenone and a mixture of {beta}-sitosterol and stigmasterol. Their structures were determined from spectral data and comparison with data from previously reported compounds. (author)

  13. A new biphenyl from Clusia melchiorii and a new tocotrienol from C. obdeltifolia

    International Nuclear Information System (INIS)

    Chromatographic purification of the dichloromethane extract of Clusia melchiorii trunk leading to the isolation of a new biphenyl, 2,2-dimethyl-5-hydroxy-7-phenylchromene, along with the known compounds 2,2-dimethyl-5,10-dihydro-2H-benzo[g]chromene-5,10-dione (xyloidone), betulinic acid, friedelin, friedelinol, euphol, sitostenone, stigmastenone and a mixture of β-sitosterol and stigmasterol. The hexane extract of Clusia obdeltifolia trunk yielded, after chromatographic fractionation, a new δ-tocotrienilic alcohol 2Z, 6E, 10E-13-(6-hydroxy- 2,8-dimethyl-3,4-dihydro-2H,2-chromenyl)-2,6,10-trimethyl- 2,6,10-tridecatrien-1-ol, along with 2Z and 2E-δ-tocotrienoloic acids, betulinic acid, betulonic acid, betunilic aldehyde, glutinol, friedelin, sitostenone and a mixture of β-sitosterol and stigmasterol. Their structures were determined from spectral data and comparison with data from previously reported compounds. (author)

  14. Flavonoids, benzophenones and a new euphane derivative from Clusia columnaris Engl. Flavonóides, benzofenonas e um novo eufano de Clusia columnaris Engl.

    Directory of Open Access Journals (Sweden)

    Reinaldo S. Compagnone

    2008-03-01

    Full Text Available The polyisoprenylated benzophenones machuone and clusiachromene A have been isolated from the fruits of Clusia columnaris. The hexane extract of the young branches with leaves afforded a new euphane derivative, whose structure was elucidated by spectroscopic methods. On the contrary, the most polar EtOAc and ButOH extracts were constituted of flavonoid C-glucosides (isovitexin, vitexin and vitexin-2"-xyloside and seven biflavonoids of the so-called Garcinia group.Dos frutos de Clusia columnaris foram isoladas as benzofenonas poliisopreniladas machuona e clusiacromeno A. Do extrato em hexano obtido de galhos e folhas novas, um novo triterpeno do tipo eufano foi isolado. Sua estrutura foi elucidada através de métodos espectroscópicos. Por outro lado, dos extratos mais polares - em acetato de etila e em butanol, foram isolados os flavonóides C-glicosilados isovitexina, vitexina e vitexina-2"-xilosídeo, além de sete bisflavonóides conhecidos como bisflavonóides do grupo da Garcinia.

  15. Density dependence in flower visitation rates of cockroach-pollinated Clusia blattophila on the Nouragues inselberg, French Guiana

    Czech Academy of Sciences Publication Activity Database

    Vlasáková, Blanka

    2015-01-01

    Roč. 31, Part 1 (2015), s. 95-98. ISSN 0266-4674 R&D Projects: GA ČR GPP505/12/P039 Institutional support: RVO:67985939 Keywords : Clusia * ockroach * density dependence Subject RIV: EF - Botanics Impact factor: 0.904, year: 2014

  16. Vertical distribution of spiders associated to Quercus humboldtii and clusia spp. at sanctuary of fauna and flora Iguaque, Colombia

    International Nuclear Information System (INIS)

    the vertical distribution of spiders associated to trees of quercus humboldtii and clusia spp. with different architectural model, was studied at sanctuary of fauna and flora of Iguaque; for this, we selected trees of each architectural model, stratified them each three m in high starting at the base to the canopy of the tree. We took samples in each stratus for 20 min during the day and at night. Also, we took samples in the nearest ground plot (4 m2). We collected 1,261 specimens of 104 morphospecies and 20 families. The most frequent families were theridiidae, salticidae, araneidae, linyphiidae, anyphaenidae, and theridiosomatidae. We observed differences in the spiders' vertical distribution in abundance, richness, composition, time period, and sex ratio, all of them attributable to plant architectures and its stratification. Clusia spider community was the most diverse, quercus spider community was the richest rain, period of time at day, and support availability affected the spiders' composition.

  17. Early detection of injuries in leaves of Clusia hilariana Schltdl. (Clusiaceae) caused by particulate deposition of iron

    OpenAIRE

    Diego Ismael Rocha; Luzimar Campos da Silva; Eduardo Gusmão Pereira; Bruno Francisco Sant' Anna-Santos; Elisa Rodrigues Gontijo; Marco Antônio Oliva

    2014-01-01

    This study aims to evaluate the prognostic value of microscopic parameters of asymptomatic leaves of Clusia hilariana Schltdl. subjected to particulate deposition of iron (2.14 mg cm-2 day-1) for 45 consecutive days. Samples of young and expanded leaves without symptoms were collected and subjected to light and scanning electron microscopy techniques. The height of the epidermal cells on both surfaces of the leaf and the thickness of the hypodermis, the chlorophyll parenchyma, and the leaf bl...

  18. Shared origins of a key enzyme during the evolution of C4 and CAM metabolism.

    Science.gov (United States)

    Christin, Pascal-Antoine; Arakaki, Monica; Osborne, Colin P; Bräutigam, Andrea; Sage, Rowan F; Hibberd, Julian M; Kelly, Steven; Covshoff, Sarah; Wong, Gane Ka-Shu; Hancock, Lillian; Edwards, Erika J

    2014-07-01

    CAM and C4 photosynthesis are two key plant adaptations that have evolved independently multiple times, and are especially prevalent in particular groups of plants, including the Caryophyllales. We investigate the origin of photosynthetic PEPC, a key enzyme of both the CAM and C4 pathways. We combine phylogenetic analyses of genes encoding PEPC with analyses of RNA sequence data of Portulaca, the only plants known to perform both CAM and C4 photosynthesis. Three distinct gene lineages encoding PEPC exist in eudicots (namely ppc-1E1, ppc-1E2 and ppc-2), one of which (ppc-1E1) was recurrently recruited for use in both CAM and C4 photosynthesis within the Caryophyllales. This gene is present in multiple copies in the cacti and relatives, including Portulaca. The PEPC involved in the CAM and C4 cycles of Portulaca are encoded by closely related yet distinct genes. The CAM-specific gene is similar to genes from related CAM taxa, suggesting that CAM has evolved before C4 in these species. The similar origin of PEPC and other genes involved in the CAM and C4 cycles highlights the shared early steps of evolutionary trajectories towards CAM and C4, which probably diverged irreversibly only during the optimization of CAM and C4 phenotypes. PMID:24638902

  19. Climate-resilient agroforestry: physiological responses to climate change and engineering of crassulacean acid metabolism (CAM) as a mitigation strategy.

    Science.gov (United States)

    Borland, Anne M; Wullschleger, Stan D; Weston, David J; Hartwell, James; Tuskan, Gerald A; Yang, Xiaohan; Cushman, John C

    2015-09-01

    Global climate change threatens the sustainability of agriculture and agroforestry worldwide through increased heat, drought, surface evaporation and associated soil drying. Exposure of crops and forests to warmer and drier environments will increase leaf:air water vapour-pressure deficits (VPD), and will result in increased drought susceptibility and reduced productivity, not only in arid regions but also in tropical regions with seasonal dry periods. Fast-growing, short-rotation forestry (SRF) bioenergy crops such as poplar (Populus spp.) and willow (Salix spp.) are particularly susceptible to hydraulic failure following drought stress due to their isohydric nature and relatively high stomatal conductance. One approach to sustaining plant productivity is to improve water-use efficiency (WUE) by engineering crassulacean acid metabolism (CAM) into C3 crops. CAM improves WUE by shifting stomatal opening and primary CO2 uptake and fixation to the night-time when leaf:air VPD is low. CAM members of the tree genus Clusia exemplify the compatibility of CAM performance within tree species and highlight CAM as a mechanism to conserve water and maintain carbon uptake during drought conditions. The introduction of bioengineered CAM into SRF bioenergy trees is a potentially viable path to sustaining agroforestry production systems in the face of a globally changing climate. PMID:25366937

  20. Artificial photosynthesis

    OpenAIRE

    Andrew C. Benniston; Anthony Harriman

    2008-01-01

    We raise here a series of critical issues regarding artificial photosynthesis with the intention of increasing awareness about what needs to be done to bring about a working prototype. Factors under consideration include energy and electron transfers, coupled redox reactions, repair mechanisms, and integrated photosystems.

  1. Reintroducing Photosynthesis

    Science.gov (United States)

    Vila, F.; Sanz, A.

    2012-01-01

    This article reports on conceptual difficulties related to photosynthesis and respiratory metabolism of a Plant Physiology course for undergraduate students that could hinder their better learning of metabolic processes. A survey of results obtained in this area during the last 10 academic years was performed, as well as a specific test, aimed to…

  2. Dramatic Photosynthesis.

    Science.gov (United States)

    Carlsson, Britta

    2003-01-01

    Presents a creative way to teach photosynthesis. Revolves around the growth of a lily planted and stored in the classroom. Combines the concepts of particle theory, transformation, and changes of phase and mass in a holistic approach. The six-step teaching sequence is founded on the notions of challenge, variation, and drama. (Author/NB)

  3. Clusiaxanthone and tocotrienol series from Clusia pernambucensis and their antileishmanial activity

    International Nuclear Information System (INIS)

    Phytochemical analysis of the ethyl acetate extract from the stem bark of Clusia pernambucensis G. Mariz, Clusiaceae, a Brazilian Cerrado species, led to the isolation and full characterization of a new xanthone, 1,7-dihydroxy-2-(3-methyl-2-butenyl)-6’,6’- dimethylpyrano(2’,3’:3,4)xanthone, namely clusiaxanthone. Four previously unreported tocotrienols from this species were also isolated. A derivative was obtained from clusiaxanthone, 1-hydroxy,7-methoxy-2-(3-methyl- 2-butenyl)-6’,6’-dimethylpyrano(2’,3’:3,4)xanthone (7-O-methylclusiaxanthone), and an additional derivative was obtained from Z-δ-tocotrienoloic acid. The structures of these compounds were established based on data from 1H and 13C nuclear magnetic resonance (1D and 2D NMR), high resolution electrospray ionization mass spectrometry (HRESIMS) and infrared spectroscopy. The clusiaxanthone and its derivative were able to control macrophage infection by Leishmania (Leishmania) amazonensis amastigotes (IC50 = 66.9 and 57.4 μM, respectively). The cytotoxicity of the compounds was assessed in BALB/c mouse peritoneal macrophages. (author)

  4. Clusiaxanthone and tocotrienol series from Clusia pernambucensis and their antileishmanial activity

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Everton M.; Freire-Filha, Lindomar G.; Espindola, Laila S., E-mail: darvenne@unb.br [Laboratorio de Farmacognosia, Universidade de Brasilia, Brasilia-DF (Brazil); Araujo, Renata M. [Instituto de Quimica, Universidade Federal do Rio Grande do Norte, Natal-RN (Brazil); Silveira, Edilberto R. [Departamento de Quimica Organica, Universidade Federal do Ceara, Fortaleza-CE (Brazil); Lopes, Norberto P. [Faculdade de Ciencias Farmaceuticas de Ribeirao Preto, Universidade de Sao Paulo, Ribeirao Preto-SP (Brazil); Paula, Jose Elias de [Laboratorio de Anatomia Vegetal, Universidade de Brasilia, 70910-900 Brasilia-DF (Brazil); Braz-Filho, Raimundo [Laboratorio de Ciencias Quimicas, Universidade Estadual do Norte Fluminense, Campos dos Goytacazes-RJ (Brazil)

    2013-07-15

    Phytochemical analysis of the ethyl acetate extract from the stem bark of Clusia pernambucensis G. Mariz, Clusiaceae, a Brazilian Cerrado species, led to the isolation and full characterization of a new xanthone, 1,7-dihydroxy-2-(3-methyl-2-butenyl)-6',6'- dimethylpyrano(2',3':3,4)xanthone, namely clusiaxanthone. Four previously unreported tocotrienols from this species were also isolated. A derivative was obtained from clusiaxanthone, 1-hydroxy,7-methoxy-2-(3-methyl- 2-butenyl)-6',6'-dimethylpyrano(2',3':3,4)xanthone (7-O-methylclusiaxanthone), and an additional derivative was obtained from Z-{delta}-tocotrienoloic acid. The structures of these compounds were established based on data from {sup 1}H and {sup 13}C nuclear magnetic resonance (1D and 2D NMR), high resolution electrospray ionization mass spectrometry (HRESIMS) and infrared spectroscopy. The clusiaxanthone and its derivative were able to control macrophage infection by Leishmania (Leishmania) amazonensis amastigotes (IC{sub 50} = 66.9 and 57.4 {mu}M, respectively). The cytotoxicity of the compounds was assessed in BALB/c mouse peritoneal macrophages. (author)

  5. Larvas de insetos associadas a Clusia hilariana Schltdl. (Clusiaceae na Restinga de Jurubatiba, RJ, Brasil Insect larvae associated with Clusia hilariana Schltdl. (Clusiaceae in the Restinga de Jurubatiba, RJ, Brazil

    Directory of Open Access Journals (Sweden)

    Vagner Reis da Silveira

    2008-01-01

    Full Text Available Clusia hilariana é uma das espécies de plantas mais abundantes no Parque Nacional, desempenhando um papel importante na dinâmica sucessional desse ecossistema de restinga. Esse trabalho apresenta a composição e aspectos ecológicos das espécies de larvas de mariposas encontradas em C. hilariana. Em 40 plantas, mensalmente vistoriadas, foram obtidas quatorze espécies de lepidópteros. Chloropaschia granitalis foi a espécie de larva mais abundante alimentando-se nessa espécie de planta.Clusia hilariana is one of the most abundant plant species in the National Park playing important role at the sucessional dynamic of the restinga ecosystem. This paper presents the composition and ecological aspects of caterpillars species found on C. hilariana. From 40 plants monthy inspected, fourteen species of Lepidoptera were obtained. Chloropaschia granitalis (Pyralidae was the most abundant species feeding on this plant species.

  6. Early detection of injuries in leaves of Clusia hilariana Schltdl. (Clusiaceae caused by particulate deposition of iron

    Directory of Open Access Journals (Sweden)

    Diego Ismael Rocha

    2014-06-01

    Full Text Available This study aims to evaluate the prognostic value of microscopic parameters of asymptomatic leaves of Clusia hilariana Schltdl. subjected to particulate deposition of iron (2.14 mg cm-2 day-1 for 45 consecutive days. Samples of young and expanded leaves without symptoms were collected and subjected to light and scanning electron microscopy techniques. The height of the epidermal cells on both surfaces of the leaf and the thickness of the hypodermis, the chlorophyll parenchyma, and the leaf blade were measured. Micromorphological injury occurred in the abaxial surface of young leaves and on both surfaces of expanded leaves. Erosion of the epicuticular wax and cuticle rupture were frequent on the adaxial surface, while on the abaxial surface of both leaves there was a loss of sinuosity on the anticlinal wall of the epidermal cells, stomatal deformity and obstruction. Micromorphometric alterations were seen in all leaf tissues except in the height of epidermic cells, probably due to the thick cuticle and prominent cuticular flanges. The highest difference in thickness of the leaf blade was seen in young leaves of plants subjected to SPMFe, indicating greater sensibility to particulate iron in comparison to the expanded leaves. The micromorphological and micromorphometric alterations in the leaf blade of Clusia hilariana Schltdl. showed the prognostic potential of these tools on the evaluation of impacts caused by the deposition of particulate matter, especially in the 'Restinga' natural vegetation, where the exposure is increasing due to the presence of iron ore industry in their surroundings.

  7. Holographic Photosynthesis

    CERN Document Server

    Aref'eva, Irina

    2016-01-01

    There are successful applications of the holographic AdS/CFT correspondence to high energy and condensed matter physics. We apply the holographic approach to photosynthesis that is an important example of nontrivial quantum phenomena relevant for life which is being studied in the emerging field of quantum biology. Light harvesting complexes of photosynthetic organisms are many-body quantum systems, in which quantum coherence has recently been experimentally shown to survive for relatively long time scales even at the physiological temperature despite the decohering effects of their environments. We use the holographic approach to evaluate the time dependence of entanglement entropy and quantum mutual information in the Fenna-Matthews-Olson (FMO) protein-pigment complex in green sulfur bacteria during the transfer of an excitation from a chlorosome antenna to a reaction center. It is demonstrated that the time evolution of the mutual information simulating the Lindblad master equation in some cases can be obt...

  8. VARIABLE-THROW CAM

    Science.gov (United States)

    Godsil, E.C.; Robinson, E.Y.

    1963-07-16

    A variable-throw cam comprising inner and outer eccentric sleeves which are adjustably locked together is described. The cam throw is varied by unlocking the inner and outer sleeves, rotating the outer sleeve relative to the inner one until the desired throw is obtained, and locking the sleeves together again. The cam is useful in applications wherein a continuously-variable throw is required, e.g., ram-and-die pressing operations, cyclic fatigue testing of materials, etc. (AEC)

  9. CAM and NK Cells

    Directory of Open Access Journals (Sweden)

    Kazuyoshi Takeda

    2004-01-01

    Full Text Available It is believed that tumor development, outgrowth and metastasis are under the surveillance of the immune system. Although both innate and acquired immune systems play roles, innate immunity is the spearhead against tumors. Recent studies have revealed the critical role of natural killer (NK cells in immune surveillance and that NK cell activity is considerably influenced by various agents, such as environmental factors, stress, foods and drugs. Some of these NK cell stimulants have been used in complementary and alternative medicine (CAM since ancient times. Therefore, the value of CAM should be re-evaluated from this point of view. In this review, we overview the intimate correlation between NK cell functions and CAM agents, and discuss possible underlying mechanisms mediating this. In particular, neuro-immune crosstalk and receptors for CAM agents are the most important and interesting candidates for such mechanisms.

  10. THE GENESIS OF PHOTOSYNTHESIS TYPES AS THE BASIS OF ECOLOGICAL EXPANSION OF HALOPHYTIC PLANTS

    Directory of Open Access Journals (Sweden)

    Pyurko O.Ye.

    2011-12-01

    Full Text Available The C3, C4, and CAM photosynthesis types are considerably differed by CO2 absorption intensity, its biochemistry, saturation level, water productivity, biological productivity, and other different features, which secure the plants survival at stress and extreme conditions. The aim of current research was to discover the photosynthesis peculiarities at halophytic plants species (Salicornia europaea L., Halimione pedunculata, Artemisia santonica L., Plantago lanceolata L. by salinity at model and natural conditions, and to generalize data in historical aspect. It was constituted that S. europaea L. was characterized by C3 photosynthesis passage which was switched on CAM CO2 fixation under soil salinity conditions till 4-4,5 %, but glycophyte A.santonica was immanent C4assimilation way of aspartate type.Analysis of literature data and own research allows to find out that in majority the C3photosynthesis dependence from environmental factors described by determinate curve with matched mathematical expression. It was suggested to generalize the data by Lagrange polynomial. The obtained results proved that the pattern of photosynthesis evolution is: C3 → C4 → CAM with commute possibilities: C3 → CAM; C4 → CAM.

  11. PreCam

    Energy Technology Data Exchange (ETDEWEB)

    Allam, Sahar S. [Fermilab; Tucker, Douglas L. [Fermilab

    2015-01-01

    The Dark Energy Survey (DES) will be taking the next step in probing the properties of Dark Energy and in understanding the physics of cosmic acceleration. A step towards the photometric calibration of DES is to have a quick, bright survey in the DES footprint (PreCam), using a pre-production set of the Dark Energy Camera (DECam) CCDs and a set of 100 mm×100 mm DES filters. The objective of the PreCam Survey is to create a network of calibrated DES grizY standard stars that will be used for DES nightly calibrations and to improve the DES global relative calibrations. Here, we describe the first year of PreCam observation, results, and photometric calibrations.

  12. CAMS achievements in 1995

    International Nuclear Information System (INIS)

    CAMS (Computerized Accident Management Support) is a system being developed as a joint research activity at the Halden Reactor Project with additional financing from the Swedish Nuclear Inspectorate (SKI) and the Nordic NKS/RAK-2 project. Three types of users are envisaged: the staff in the control room, the staff in the technical support centre and the staff at a national emergency centre. It is still an experimental system. The Swedish Nuclear Inspectorate kindly accepted to test CAMS at a safety exercise on the 4th of May, 1995. CAMS is designed assuming automatic data transfer from the plant. Missing the data link, a simulator running in the next room was updated now and then with data received by phone. As seen from CAMS, it did not matter if the data came from a fake plant or from a real plant, except that the data were delayed. Overall, it seemed that CAMS can be a very important tool for a national authority. A data link from the plant would increase its usefulness. Several comments on design features were collected and will be used to improve the system. The model needs more inputs to control the main parameters, and a larger repertoire of fault conditions should be put into the model. In the second half of 1995 the work on CAMS has concentrated upon designing new modules for signal validation, tracking simulation and state identification. This will provide better capabilities for on-line monitoring and assessment of the plant state. Further, it has been proposed to introduce Probabilistic Safety Assessment (PSA) to assist in risk monitoring. A first prototype has been made on a personal computer showing the main features of such a PSA module. (au)

  13. Modeling analysis of the benefits of Crassulacean acid metabolism (CAM) for sustainable agriculture in arid regions

    Science.gov (United States)

    Bartlett, M. S.; Vico, G.; Porporato, A. M.

    2012-12-01

    In view of the pressing needs to sustainably manage water and soil resources, especially in arid and semi-arid regions, here we propose a new carbon assimilation model that couples a simple yet mechanistic description of Crassulacean acid metabolism (CAM) photosynthesis to the soil-plant-atmosphere continuum. The model captures the full coupling of the CAM photosynthetic pathway with fluctuations in environmental conditions (cycles of light availability and air humidity, changes in soil moisture as driven by plant transpiration and rainfall occurrence). As such, the model is capable of reproducing the different phases of CAM, including daytime stomatal closure and photosynthesis from malic acid, afternoon stomatal opening for direct carbon assimilation, and nighttime stomatal opening for CO2 uptake and malic acid synthesis. Thanks to its versatility, our model allows us to relate CAM productivity, for both obligate and facultative CAM plants, to various soil moisture conditions including hydroclimatic scenarios of rainfall frequency and intensity as well as different night-time conditions of temperature, wind speed, and humidity. Our analyses show the potential productive benefits of CAM cultivation in dryland environments as feedstock and possible biofuel source, in terms of sustainable water use and economic benefits. In particular, the model is used to explore conditions where CAM plant resiliency to water stress makes these plants a more sustainable alternative to C3 and C4 species for potential deficit irrigation.

  14. Australia lacks stem succulents but is it depauperate in plants with crassulacean acid metabolism (CAM)?

    Science.gov (United States)

    Holtum, Joseph Am; Hancock, Lillian P; Edwards, Erika J; Crisp, Michael D; Crayn, Darren M; Sage, Rowan; Winter, Klaus

    2016-06-01

    In the flora of Australia, the driest vegetated continent, crassulacean acid metabolism (CAM), the most water-use efficient form of photosynthesis, is documented in only 0.6% of native species. Most are epiphytes and only seven terrestrial. However, much of Australia is unsurveyed, and carbon isotope signature, commonly used to assess photosynthetic pathway diversity, does not distinguish between plants with low-levels of CAM and C3 plants. We provide the first census of CAM for the Australian flora and suggest that the real frequency of CAM in the flora is double that currently known, with the number of terrestrial CAM species probably 10-fold greater. Still unresolved is the question why the large stem-succulent life - form is absent from the native Australian flora even though exotic large cacti have successfully invaded and established in Australia. PMID:27088716

  15. Caracterización por cromatografía de gases/espectrometría de masas del extracto apolar de las hojas de Clusia minor L.

    OpenAIRE

    Mangas Marín, Raisa; Montes de Oca Porto, Rodny; Bello Alarcón, Adonis; Nival Vázquez Lavín, Alejandro

    2008-01-01

    El estudio de la composición química de la fracción apolar de las hojas de la especie Clusia minor L. con el empleo de la Cromatografía de Gases/Espectrometría de Masas, permitió el aislamiento e identificación de 25 compuestos, en su mayoría, terpenoides y esteroides, volátiles y otros. Un gran número de estos constituyen nuevos reportes para la especie. El sitosterol y el estigmasterol, el lupeol y la α-amirina fueron, respectivamente, los esteroides y triterpenos más abundantes. Co...

  16. THE GENESIS OF PHOTOSYNTHESIS TYPES AS THE BASIS OF ECOLOGICAL EXPANSION OF HALOPHYTIC PLANTS

    OpenAIRE

    Pyurko O. Ye.

    2011-01-01

    The C3, C4, and CAM photosynthesis types are considerably differed by CO2 absorption intensity, its biochemistry, saturation level, water productivity, biological productivity, and other different features, which secure the plants survival at stress and extreme conditions. The aim of current research was to discover the photosynthesis peculiarities at halophytic plants species (Salicornia europaea L., Halimione pedunculata, Artemisia santonica L., Plantago lanceolata L.) by salinity at model ...

  17. A roadmap for research on crassulacean acid metabolism (CAM) to enhance sustainable food and bioenergy production in a hotter, drier world.

    Science.gov (United States)

    Yang, Xiaohan; Cushman, John C; Borland, Anne M; Edwards, Erika J; Wullschleger, Stan D; Tuskan, Gerald A; Owen, Nick A; Griffiths, Howard; Smith, J Andrew C; De Paoli, Henrique C; Weston, David J; Cottingham, Robert; Hartwell, James; Davis, Sarah C; Silvera, Katia; Ming, Ray; Schlauch, Karen; Abraham, Paul; Stewart, J Ryan; Guo, Hao-Bo; Albion, Rebecca; Ha, Jungmin; Lim, Sung Don; Wone, Bernard W M; Yim, Won Cheol; Garcia, Travis; Mayer, Jesse A; Petereit, Juli; Nair, Sujithkumar S; Casey, Erin; Hettich, Robert L; Ceusters, Johan; Ranjan, Priya; Palla, Kaitlin J; Yin, Hengfu; Reyes-García, Casandra; Andrade, José Luis; Freschi, Luciano; Beltrán, Juan D; Dever, Louisa V; Boxall, Susanna F; Waller, Jade; Davies, Jack; Bupphada, Phaitun; Kadu, Nirja; Winter, Klaus; Sage, Rowan F; Aguilar, Cristobal N; Schmutz, Jeremy; Jenkins, Jerry; Holtum, Joseph A M

    2015-08-01

    Crassulacean acid metabolism (CAM) is a specialized mode of photosynthesis that features nocturnal CO2 uptake, facilitates increased water-use efficiency (WUE), and enables CAM plants to inhabit water-limited environments such as semi-arid deserts or seasonally dry forests. Human population growth and global climate change now present challenges for agricultural production systems to increase food, feed, forage, fiber, and fuel production. One approach to meet these challenges is to increase reliance on CAM crops, such as Agave and Opuntia, for biomass production on semi-arid, abandoned, marginal, or degraded agricultural lands. Major research efforts are now underway to assess the productivity of CAM crop species and to harness the WUE of CAM by engineering this pathway into existing food, feed, and bioenergy crops. An improved understanding of CAM has potential for high returns on research investment. To exploit the potential of CAM crops and CAM bioengineering, it will be necessary to elucidate the evolution, genomic features, and regulatory mechanisms of CAM. Field trials and predictive models will be required to assess the productivity of CAM crops, while new synthetic biology approaches need to be developed for CAM engineering. Infrastructure will be needed for CAM model systems, field trials, mutant collections, and data management. PMID:26153373

  18. Photosynthesis and Plant Productivity.

    Science.gov (United States)

    Zelitch, Israel

    1979-01-01

    Research in photosynthesis is revealing a number of possible ways to increase the efficiency of carbon dioxide assimilation by crops and thus increase yields, a necessity in times of growing population and shrinking agricultural land. (Author/BB)

  19. Hydraulic involute cam actuator

    Science.gov (United States)

    Love, Lonnie J.; Lind, Randall F.

    2011-11-01

    Mechanical joints are provided in which the angle between a first coupled member and a second coupled member may be varied by mechanical actuators. In some embodiments the angle may be varied around a pivot axis in one plane and in some embodiments the angle may be varied around two pivot axes in two orthogonal planes. The joints typically utilize a cam assembly having two lobes with an involute surface. Actuators are configured to push against the lobes to vary the rotation angle between the first and second coupled member.

  20. Carbon isotopes in photosynthesis

    International Nuclear Information System (INIS)

    The efficiency of photosynthesis continues to interest biochemists, biologists, and plant physiologists. Scientists interested in CO2 uptake are concerned about the extent to which the uptake rate is limited by such factors as stomatal diffusion and the chemistry of the CO2 absorption process. The fractionation of carbon isotopes that occurs during photosynthesis is one of the most useful techniques for investigating the efficiency of CO2 uptake

  1. Oxygenic photosynthesis without galactolipids

    OpenAIRE

    Awai, Koichiro; Ohta, Hiroyuki; Sato, Naoki

    2014-01-01

    Cyanobacteria, as well as chloroplasts of plants and algae, are the sites of photosynthesis that produces oxygen. Photosynthetic membranes, also known as thylakoid membranes, in these organisms contain galactolipids, without exception, as the major components. Galactolipids are thus believed to be important for photosynthesis or at least for the formation of the flattened shape of thylakoid membranes. The biosynthetic pathway of galactolipids is definitely different in plants and cyanobacteri...

  2. CAD/CAM data management

    Science.gov (United States)

    Bray, O. H.

    1984-01-01

    The role of data base management in CAD/CAM, particularly for geometric data is described. First, long term and short term objectives for CAD/CAM data management are identified. Second, the benefits of the data base management approach are explained. Third, some of the additional work needed in the data base area is discussed.

  3. DISTRIBUCIÓN VERTICAL DE ARAÑAS ASOCIADAS A Quercus humboldtii Y Clusia spp. EN EL SANTUARIO DE FAUNA Y FLORA IGUAQUE, COLOMBIA Vertical Distribution of Spiders Associated to Quercus humboldtii and Clusia spp. at Sanctuary of Fauna and Flora Iguaque, Colombia

    Directory of Open Access Journals (Sweden)

    SILVIA VANEGAS

    2012-12-01

    Full Text Available Se estudió la distribución vertical de arañas asociadas a árboles de Quercus humboldtii y Clusia spp. con diferentes modelos arquitecturales en el Santuario de Fauna y Flora Iguaque, Colombia. Se seleccionaron árboles de cada modelo arquitectural, estratificándolos verticalmente cada tres metros desde la base hasta el dosel. Se realizaron colectas en cada estrato por 20 minutos durante el día y en la noche. También se tomaron muestras en la parcela aledaña (4 m². Se colectaron 1261 individuos pertenecientes a 104 morfoespecies y 20 familias; las familias más frecuentes fueron Theridiidae, Salticidae, Araneidae, Linyphiidae, Anyphaenidae y Theridiosomatidae. Se encontraron diferencias en la distribución vertical de arañas en cuanto a la abundancia, la riqueza, la composición, la distribución de sexos y las épocas climáticas atribuibles a las arquitecturas vegetales y a su estratificación. Clusia presentó la comunidad de arañas más diversa, Quercus la de mayor dominancia. La composición estuvo influida por las lluvias, el período del día y la disponibilidad de soportes vegetales.The vertical distribution of spiders associated to trees of Quercus humboldtii and Clusia spp. with different architectural model, was studied at Sanctuary of Fauna and Flora of Iguaque; for this, we selected trees of each architectural model, stratified them each three m in high starting at the base to the canopy of the tree. We took samples in each stratus for 20 min during the day and at night. Also, we took samples in the nearest ground plot (4 m². We collected 1,261 specimens of 104 morphospecies and 20 families. The most frequent families were Theridiidae, Salticidae, Araneidae, Linyphiidae, Anyphaenidae, and Theridiosomatidae. We observed differences in the spiders' vertical distribution in abundance, richness, composition, time period, and sex ratio, all of them attributable to plant architectures and its stratification. Clusia spider

  4. DISTRIBUCIÓN VERTICAL DE ARAÑAS ASOCIADAS A Quercus humboldtii Y Clusia spp. EN EL SANTUARIO DE FAUNA Y FLORA IGUAQUE, COLOMBIA Vertical Distribution of Spiders Associated to Quercus humboldtii and Clusia spp. at Sanctuary of Fauna and Flora Iguaque, Colombia

    OpenAIRE

    SILVIA VANEGAS; GIOVANNY FAGUA; EDUARDO FLÓREZ

    2012-01-01

    Se estudió la distribución vertical de arañas asociadas a árboles de Quercus humboldtii y Clusia spp. con diferentes modelos arquitecturales en el Santuario de Fauna y Flora Iguaque, Colombia. Se seleccionaron árboles de cada modelo arquitectural, estratificándolos verticalmente cada tres metros desde la base hasta el dosel. Se realizaron colectas en cada estrato por 20 minutos durante el día y en la noche. También se tomaron muestras en la parcela aledaña (4 m²). Se colectaron 1261 individuo...

  5. Optimisation Methods for Cam Mechanisms

    Directory of Open Access Journals (Sweden)

    Claudia–Mari Popa

    2010-01-01

    Full Text Available In this paper we present the criteria which represent the base of optimizing the cam mechanisms and also we perform the calculations for several types of mechanisms. We study the influence of the constructive parameters in case of the simple machines with rotation cam and follower (flat or curve of translation on the curvature radius and that of the transmission angle. As it follows, we present the optimization calculations of the cam and flat rotation follower mechanisms, as well as the calculations for optimizing the cam mechanisms by circular groove followers’ help. For an easier interpretation of the results, we have visualized the obtained cam in AutoCAD according to the script files generated by a calculation program.

  6. The Evolution of Photosynthesis

    International Nuclear Information System (INIS)

    This Review was written by Engelbert Broda, an Austrian Chemist and Physicist, on February the 10th 1976. The merits of the inductive and the deductive approach in tracing the pathways of evolution are discussed. Using the latter approach, it is concluded that photosynthesis followed fermentation as a method of obtaining energy-rich compounds, especially ATP. Photosynthesis probably arose by utilization of membranes for bioenergetic processes. Originally photosynthesis served photophosphorylation (ATP production), later reducing power was also made, either by open-ended, light-powered, electron flow or driven by ATP; ultimate electron donors were at first hydrogen or sulfur compounds, and later water, the last-named capability Was acquired by prokaryotic algae the earliest plants, similar to the recent blue-greens. When free oxygen entered the atmosphere for the first time, various forms of respiration (oxidative phosphorylation) became possible. Mechanistically, respiration evolved from photosynthesis (‘conversion hypotheses’). Prokaryotic algae are probably the ancestors of the chloroplasts in the eukaryotes, In the evolution of the eukaryotes, not much change in the basic processes of photosynthesis occurred.(author)

  7. Distribución vertical de arañas asociadas a quercus humboldtii y clusia spp. en el santuario de fauna y flora iguaque, colombia

    OpenAIRE

    VANEGAS, SILVIA; FAGUA, GIOVANNY; FLOREZ, EDUARDO

    2012-01-01

    Se estudió la distribución vertical de arañas asociadas a Quercus humboldtii y Clusia spp. en el Santuario de Fauna y Flora Iguaque, para esto se seleccionaron 10 árboles de cada género estratificándolos verticalmente cada 3m desde la base hasta el dosel. Se realizaron colectas en cada estrato por 20 min durante el día y en la noche. También se tomaron muestras en la parcela aledaña (4 m2). Se colectaron 1.261 individuos pertenecientes a 104 morfoespecies y 20 familias; las más frecuentes fue...

  8. Rad Pole Cam Development

    International Nuclear Information System (INIS)

    The RadPoleCam was developed to provide Department Of Energy (DOE) first responders the capability to assess the radiological and visual condition of remote or inaccessible locations. Real time gamma isotopic identification is provided to the first responder in the form of audio feedback (i.e. spoken through head phones) from a gamma detector mounted on a collapsible pole that can extend from 1 to 9 meters (6 to 29 feet). Simultaneously, selectable direct and side looking visual images are provided from the 5cm (2in) diameter, waterproof probe tip. The lightweight, self contained, ruggedized, system will provide a rapidly deployable field system for visual and radiological search and assessment of confined spaces and extended reach locations

  9. Time to Talk about CAM

    Science.gov (United States)

    ... Home Current Issue Past Issues Special Section CAM Time to Talk Past Issues / Winter 2009 Table of ... helps to ensure your coordinated, safe care. NCCAM's Time to Talk program is just right for talking ...

  10. Teaching Photosynthesis with ELL Students

    Science.gov (United States)

    Piper, Susan; Shaw, Edward Lewis, Jr.

    2010-01-01

    Although the teaching of photosynthesis occurs yearly in elementary classrooms, one thing that makes it challenging is the inclusion of English language learners (ELLs). This article presents several activities for teaching and assessing of photosynthesis in a third grade classroom. The activities incorporate the photosynthesis content, teaching…

  11. Leaf absorbance and photosynthesis

    Science.gov (United States)

    Schurer, Kees

    1994-01-01

    The absorption spectrum of a leaf is often thought to contain some clues to the photosynthetic action spectrum of chlorophyll. Of course, absorption of photons is needed for photosynthesis, but the reverse, photosynthesis when there is absorption, is not necessarily true. As a check on the existence of absorption limits we measured spectra for a few different leaves. Two techniques for measuring absorption have been used, viz. the separate determination of the diffuse reflectance and the diffuse transmittance with the leaf at a port of an integrating sphere and the direct determination of the non-absorbed fraction with the leaf in the sphere. In a cross-check both methods yielded the same results for the absorption spectrum. The spectrum of a Fuchsia leaf, covering the short-wave region from 350 to 2500 nm, shows a high absorption in UV, blue and red, the well known dip in the green and a steep fall-off at 700 nm. Absorption drops to virtually zero in the near infrared, with subsequent absorptions, corresponding to the water absorption bands. In more detailed spectra, taken at 5 nm intervals with a 5 nm bandwidth, differences in chlorophyll content show in the different depths of the dip around 550 nm and in a small shift of the absorption edge at 700 nm. Spectra for Geranium (Pelargonium zonale) and Hibiscus (with a higher chlorophyll content) show that the upper limit for photosynthesis can not be much above 700 nm. No evidence, however, is to be seen of a lower limit for photosynthesis and, in fact, some experiments down to 300 nm still did not show a decrease of the absorption although it is well recognized that no photosynthesis results with 300 nm wavelengths.

  12. Hyper Suprime-Cam

    Science.gov (United States)

    Miyazaki, Satoshi; Komiyama, Yutaka; Nakaya, Hidehiko; Kamata, Yukiko; Doi, Yoshi; Hamana, Takashi; Karoji, Hiroshi; Furusawa, Hisanori; Kawanomoto, Satoshi; Morokuma, Tomoki; Ishizuka, Yuki; Nariai, Kyoji; Tanaka, Yoko; Uraguchi, Fumihiro; Utsumi, Yousuke; Obuchi, Yoshiyuki; Okura, Yuki; Oguri, Masamune; Takata, Tadafumi; Tomono, Daigo; Kurakami, Tomio; Namikawa, Kazuhito; Usuda, Tomonori; Yamanoi, Hitomi; Terai, Tsuyoshi; Uekiyo, Hatsue; Yamada, Yoshihiko; Koike, Michitaro; Aihara, Hiro; Fujimori, Yuki; Mineo, Sogo; Miyatake, Hironao; Yasuda, Naoki; Nishizawa, Jun; Saito, Tomoki; Tanaka, Manobu; Uchida, Tomohisa; Katayama, Nobu; Wang, Shiang-Yu; Chen, Hsin-Yo; Lupton, Robert; Loomis, Craig; Bickerton, Steve; Price, Paul; Gunn, Jim; Suzuki, Hisanori; Miyazaki, Yasuhito; Muramatsu, Masaharu; Yamamoto, Koei; Endo, Makoto; Ezaki, Yutaka; Itoh, Noboru; Miwa, Yoshinori; Yokota, Hideo; Matsuda, Toru; Ebinuma, Ryuichi; Takeshi, Kunio

    2012-09-01

    Hyper Suprime-Cam (HSC) is an 870 Mega pixel prime focus camera for the 8.2 m Subaru telescope. The wide field corrector delivers sharp image of 0.25 arc-sec FWHM in r-band over the entire 1.5 degree (in diameter) field of view. The collimation of the camera with respect to the optical axis of the primary mirror is realized by hexapod actuators whose mechanical accuracy is few microns. As a result, we expect to have seeing limited image most of the time. Expected median seeing is 0.67 arc-sec FWHM in i-band. The sensor is a p-ch fully depleted CCD of 200 micron thickness (2048 x 4096 15 μm square pixel) and we employ 116 of them to pave the 50 cm focal plane. Minimum interval between exposures is roughly 30 seconds including reading out arrays, transferring data to the control computer and saving them to the hard drive. HSC uniquely features the combination of large primary mirror, wide field of view, sharp image and high sensitivity especially in red. This enables accurate shape measurement of faint galaxies which is critical for planned weak lensing survey to probe the nature of dark energy. The system is being assembled now and will see the first light in August 2012.

  13. Operation of the Xanthophyll Cycle and Degradation of D1 Protein in the Inducible CAM plant, Talinum triangulare, under Water Deficit

    OpenAIRE

    PIETERS, ALEJANDRO J.; Tezara, Wilmer; Herrera, Ana

    2003-01-01

    Changes in photochemical activity induced by water deficit were investigated in Talinum triangulare, an inducible CAM plant. The aim was to analyse the interactions between C3 photosynthesis, induction and activity of CAM, photosynthetic energy regulation and the mechanisms responsible for photoprotection and photoinhibition under water stress. Gas exchange, chlorophyll a fluorescence, titratable acidity, carotenoid composition and relative contents of the PSII reaction centre protein (D1) we...

  14. Special Section: Complementary and Alternative Medicine (CAM): Low Back Pain and CAM

    Science.gov (United States)

    ... Current Issue Past Issues Special Section CAM Low Back Pain and CAM Past Issues / Winter 2009 Table of ... from CAM treatment for conditions such as low back pain. Photo courtesy of Glenn Scimonelli "Oh, my aching ...

  15. Transcriptome Analysis of Drought-Tolerant CAM plants Agave deserti and Agave tequilana

    OpenAIRE

    Gross, Stephen M.

    2013-01-01

    Agaves are succulent monocotyledonous plants native to hot and arid environments of North America. Because of their adaptations to their environment, including crassulacean acid metabolism (CAM, a water-efficient form of photosynthesis) and existing technologies for ethanol production, agaves have gained attention both as potential lignocellulosic bioenergy feedstocks and models for exploring plant responses to abiotic stress. However, the lack of comprehensive Agave sequence datasets limits ...

  16. De novo transcriptome assembly of drought tolerant CAM plants, Agave deserti and Agave tequilana

    OpenAIRE

    Gross, Stephen M.; Martin, Jeffrey A.; Simpson, June; Abraham-Juarez, María Jazmín; Wang, Zhong; Visel, Axel

    2013-01-01

    Background Agaves are succulent monocotyledonous plants native to xeric environments of North America. Because of their adaptations to their environment, including crassulacean acid metabolism (CAM, a water-efficient form of photosynthesis), and existing technologies for ethanol production, agaves have gained attention both as potential lignocellulosic bioenergy feedstocks and models for exploring plant responses to abiotic stress. However, the lack of comprehensive Agave sequence datasets li...

  17. Crassulacean acid metabolism enhances underwater photosynthesis and diminishes photorespiration in the aquatic plant Isoetes australis

    DEFF Research Database (Denmark)

    Pedersen, Ole; Rich, S.M.; Pulido Pérez, Cristina;

    2011-01-01

    were evaluated for Isoetes australis, a submerged plant that inhabits shallow temporary rock pools. • Leaves high or low in malate were evaluated for underwater net photosynthesis and apparent photorespiration at a range of CO2 and O2 concentrations. • CAM activity was indicated by 9.7-fold higher leaf...

  18. New Concept of Photosynthesis

    Directory of Open Access Journals (Sweden)

    Komissarov Gennadiy Germanovich

    2014-12-01

    Full Text Available The history of the formation of a new concept of photosynthesis proposed by the author is considered for the period since 1966 to 2013. Its essence consists in the following facts: the photosynthetic oxygen (hydrogen source is not water, but exo- and endogenous hydrogen peroxide; thermal energy is a necessary part of the photosynthetic process; along with the carbon dioxide the air (oxygen, inert gases is included in the photosynthetic equation. The mechanism of the photovoltaic (Becquerel effect in films of chlorophyll and its synthetic analogue - phthalocyanine are briefly touched upon in the article. The article presents the works on artificial photosynthesis performed in the laboratory of Photobionics of N.N. Semenov Institute of Chemical Physics, RAS.

  19. New Concept of Photosynthesis

    OpenAIRE

    Komissarov Gennadiy Germanovich

    2014-01-01

    The history of the formation of a new concept of photosynthesis proposed by the author is considered for the period since 1966 to 2013. Its essence consists in the following facts: the photosynthetic oxygen (hydrogen) source is not water, but exo- and endogenous hydrogen peroxide; thermal energy is a necessary part of the photosynthetic process; along with the carbon dioxide the air (oxygen, inert gases) is included in the photosynthetic equation. The mechanism of the photovoltaic (Becquerel)...

  20. Carotenoids and Photosynthesis.

    Science.gov (United States)

    Hashimoto, Hideki; Uragami, Chiasa; Cogdell, Richard J

    2016-01-01

    Carotenoids are ubiquitous and essential pigments in photosynthesis. They absorb in the blue-green region of the solar spectrum and transfer the absorbed energy to (bacterio-)chlorophylls, and so expand the wavelength range of light that is able to drive photosynthesis. This is an example of singlet-singlet energy transfer, and so carotenoids serve to enhance the overall efficiency of photosynthetic light reactions. Carotenoids also act to protect photosynthetic organisms from the harmful effects of excess exposure to light. Triplet-triplet energy transfer from chlorophylls to carotenoids plays a key role in this photoprotective reaction. In the light-harvesting pigment-protein complexes from purple photosynthetic bacteria and chlorophytes, carotenoids have an additional role of structural stabilization of those complexes. In this article we review what is currently known about how carotenoids discharge these functions. The molecular architecture of photosynthetic systems will be outlined first to provide a basis from which to describe carotenoid photochemistry, which underlies most of their important functions in photosynthesis. PMID:27485220

  1. The dawn of photosynthesis.

    Science.gov (United States)

    Pennazio, Sergio

    2011-01-01

    Photosynthesis may be hold the most important process of plant nutrition, whose essential principles, viz. water, earth, and air, were stated by E. Mariotte and S. Hales between the second half of the seventeenth and the first half of the eighteenth centuries. Subsequently, the pneumatic chemistry demonstrated that the atmospheric air was composed of different kinds of gases. In this context, J. Priestley discovered, in 1772, that the unbreathable air containing high amount of "fixed air" (carbon dioxide) could be made breathable by plants. This English chemist perhaps sensed the importance of this discovery as for the physiology of plant, whilst such importance was clearly perceived by the Dutch physician Jan Ingenhouse. He collected, between 1779 and 1796, a series of experimental results into a reliable hypothesis whose protagonists were air, water and light. Ingenhousz's work was substantiated by the results of the Swiss physiologists Jean Senebier and, in particular, by those of Théodore de Saussure. This latter, in 1804, transformed the hypothesis into a true theory that defined the elaboration of carbon dioxide as nutritional process, and the release of oxygen as a by-product. This theory constituted the ground of photosynthesis for the two successive centuries, distinguished by exciting and splendid research which transformed photosynthesis research into a classic work of scientific genius. PMID:25095597

  2. Estrutura do estrato herbáceo na formação aberta de Clusia do Parque Nacional da Restinga de Jurubatiba, RJ, Brasil Herb layer structure of Clusia scrub in the Restinga de Jurubatiba National Park, Rio de Janeiro, Brazil

    OpenAIRE

    Miriam Cristina Alvarez Pereira; Sandra Zorat Cordeiro; Dorothy Sue Dunn de Araujo

    2004-01-01

    No Parque Nacional da Restinga de Jurubatiba localiza-se o site 5 do Programa de Pesquisas Ecológicas de Longa Duração (PELD), região de grande diversidade de hábitats e riqueza florística nas restingas do Norte do Estado do Rio de Janeiro. Para descrever a composição florística e estrutura do estrato herbáceo da formação aberta de Clusia foram amostrados todos os indivíduos deste estrato utilizando-se o método de parcelas. Em três diferentes áreas foram distribuídos 200 quadrados de 1m², tot...

  3. IBD and Complementary and Alternative Medicine (CAM)

    Science.gov (United States)

    ... Alternative Medicine (CAM) Go Back Complementary and Alternative Medicine (CAM) Email Print + Share Crohn’s disease and ulcerative ... Energy Medicine, and Biologically-Based Practices. Mind-Body Medicine Mind-body medicine is a set of interventions ...

  4. The detection of EpCAM(+) and EpCAM(-) circulating tumor cells

    NARCIS (Netherlands)

    de Wit, Sanne; van Dalum, Guus; Lenferink, Aufried T. M.; Tibbe, Arjan G. J.; Hiltermann, T. Jeroen N.; Groen, Harry J. M.; van Rijn, Cees J. M.; Terstappen, Leon W. M. M.

    2015-01-01

    EpCAM expressing circulating tumor cells, detected by CellSearch, are predictive of short survival in several cancers and may serve as a liquid biopsy to guide therapy. Here we investigate the presence of EpCAM(+) CTC detected by CellSearch and EpCAM(-) CTC discarded by CellSearch, after EpCAM based

  5. The Z CamPaign: Year Five

    CERN Document Server

    Simonsen, Mike

    2014-01-01

    Entering into the fifth year of the Z CamPaign, the author has developed a website summarizing our findings which will also act as a living catalog of bona fide Z Cam stars, suspected Z Cams and Z Cam impostors. In this paper we summarize the findings of the first four years of research, introduce the website and its contents to the public and discuss the way forward into year five and beyond.

  6. The detection of EpCAM

    NARCIS (Netherlands)

    Wit, De Sanne; Dalum, Van Guus; Lenferink, Aufried T.M.; Tibbe, Arjan G.J.; Hiltermann, T.J.N.; Groen, Harry J.M.; Rijn, Van C.J.M.; Terstappen, Leon W.M.M.

    2015-01-01

    EpCAM expressing circulating tumor cells, detected by CellSearch, are predictive of short survival in several cancers and may serve as a liquid biopsy to guide therapy. Here we investigate the presence of EpCAM+ CTC detected by CellSearch and EpCAM- CTC discarded by CellSear

  7. CAMS: Computerized Accident Management Support

    International Nuclear Information System (INIS)

    The OECD Halden Reactor Project has initiated a new research programme on computerised accident management support, the so-called CAMS project (CAMS = Computerized Accident Management Support). This work will investigate the possibilities for developing systems which provide more extensive support to the control room staff and technical support centre than the existing SPDS (Safety Parameter Display System) type of systems. The CAMS project will utilize available simulator codes and the capabilities of computerized tools to assist the plant staff during the various accident stages including: identification of the accident state, assessment of the future development of the accident, and planning accident mitigation strategies. This research programme aims at establishing a prototype system which can be used for experimental testing of the concept and serve as a tool for training and education in accident management. The CAMS prototype should provide support to the staff when the plant is in a normal state, in a disturbance sate, and in an accident state. Even though better support in an accident state is the main goal of the project, it is felt to be important that the staff is familiar with the use of the system during normal operation, when they utilize the system during transients

  8. Photosynthesis: 1900-1930.

    Science.gov (United States)

    Pennazio, Sergio

    2007-01-01

    During the second half of the 19th century Julius von Sachs established the main principles of the photosynthetic production of sugars. From then, a growing number of biochemists and physiologists attended to the process, that appeared like a "black box", in order to detect what came in and what went out of it. The English group of Frederick Blackman gave a remarkable contribution in individuating the close connection between temperature, light and CO2 concentration. Later, the great importance of light was stressed by Otto Warburg, who evaluated the radiant energy necessary to the process in terms of quantum theory. The biochemical mechanism of photosynthesis was interpreted by the main European schools on the basis of Adolf Baeyer's suggestion which posed formaldehyde as the core of the process. Formaldehyde's theory hold engaged the biochemists for about fifty years although some voices rose up against it. However, nobody could put forward more coherent theories until the 1940s, when Sam Ruben and Martin Kamen individuated the cyclic pattern of the process. Ultimately, the first thirty years of the 20th century must be seen as a preliminary stage studded with light and shade even if, in spite of controversial trends, several findings of remarkable interest became to disclose that "black box" as we know today chlorophyll photosynthesis. PMID:18278741

  9. Evolution of Oxygenic Photosynthesis

    Science.gov (United States)

    Fischer, Woodward W.; Hemp, James; Johnson, Jena E.

    2016-06-01

    The origin of oxygenic photosynthesis was the most important metabolic innovation in Earth history. It allowed life to generate energy and reducing power directly from sunlight and water, freeing it from the limited resources of geochemically derived reductants. This greatly increased global primary productivity and restructured ecosystems. The release of O2 as an end product of water oxidation led to the rise of oxygen, which dramatically altered the redox state of Earth's atmosphere and oceans and permanently changed all major biogeochemical cycles. Furthermore, the biological availability of O2 allowed for the evolution of aerobic respiration and novel biosynthetic pathways, facilitating much of the richness we associate with modern biology, including complex multicellularity. Here we critically review and synthesize information from the geological and biological records for the origin and evolution of oxygenic photosynthesis. Data from both of these archives illustrate that this metabolism first appeared in early Paleoproterozoic time and, despite its biogeochemical prominence, is a relatively late invention in the context of our planet's history.

  10. Measuring and modelling ecosystem productivity: a PhenoCam-based approach.

    Science.gov (United States)

    Hufkens, K.; Keenan, T. F.; Flanagan, L. B.; Richardson, A. D.

    2015-12-01

    Phenology controls feedbacks to the climate system through abiotic and biotic forces such as albedo or fluxes of water, energy and CO2. Understanding and modelling these vegetation-climate feedbacks is key to accurately predicting a future climate. For the past 6 years the PhenoCam network, a network of near-surface remote sensing cameras, has consistently monitored vegetation phenology in a wide range of ecoregions, climate zones, and plant functional types. Here we explore the tight coupling between canopy greenness and rates of photosynthesis using two studies. A first study highlights how PhenoCam data can be used to quantify the effect of a late spring frost event on ecosystem productivity, introducing a 7-14% loss in annual gross productivity across 8753 km2 in the northeastern United States. This case study emphasizes the use of the PhenoCam data in estimating productivity loss / the opportunity cost of ecosystem disturbance in areas not covered by ecosystem flux measurement equipment. In a more recent, second, study we developed a PhenoCam data-informed pulse-response model of grassland growth to explore potential responses of grasslands to future climate change across North America. Our findings projected widespread and consistent increase in grassland productivity (for the current range of grassland ecosystems of North American) over the coming century, despite a general increase in aridity projected across most of our study area. Once more PhenoCam data allowed us to inform our modelling efforts with data of a high temporal and spatial resolution. In conclusion, both studies illustrate direct applications of the ever growing PhenoCam network (http://phenocam.sr.unh.edu/webcam/) in scaling the effects of ecosystem disturbances, predicting future ecosystem productivity and underscore the complementary nature of PhenoCam data with ecosystem exchange measurements.

  11. Fruit photosynthesis in Satsuma mandarin.

    Science.gov (United States)

    Hiratsuka, Shin; Suzuki, Mayu; Nishimura, Hiroshi; Nada, Kazuyoshi

    2015-12-01

    To clarify detailed characteristics of fruit photosynthesis, possible gas exchange pathway and photosynthetic response to different environments were investigated in Satsuma mandarin (Citrus unshiu). About 300 mm(-2) stomata were present on fruit surface during young stages (∼10-30 mm diameter fruit) and each stoma increased in size until approximately 88 days after full bloom (DAFB), while the stomata collapsed steadily thereafter; more than 50% stomata deformed at 153 DAFB. The transpiration rate of the fruit appeared to match with stoma development and its intactness rather than the density. Gross photosynthetic rate of the rind increased gradually with increasing CO2 up to 500 ppm but decreased at higher concentrations, which may resemble C4 photosynthesis. In contrast, leaf photosynthesis increased constantly with CO2 increment. Although both fruit and leaf photosynthesis were accelerated by rising photosynthetic photon flux density (PPFD), fruit photosynthesis was greater under considerably lower PPFD from 13.5 to 68 μmolm(-2)s(-1). Thus, Satsuma mandarin fruit appears to incorporate CO2 through fully developed and non-collapsed stomata, and subject it to fruit photosynthesis, which may be characterized as intermediate status among C3, C4 and shade plant photosynthesis. The device of fruit photosynthesis may develop differently from its leaf to capture CO2 efficiently. PMID:26706059

  12. Principles of Natural Photosynthesis.

    Science.gov (United States)

    Krewald, Vera; Retegan, Marius; Pantazis, Dimitrios A

    2016-01-01

    Nature relies on a unique and intricate biochemical setup to achieve sunlight-driven water splitting. Combined experimental and computational efforts have produced significant insights into the structural and functional principles governing the operation of the water-oxidizing enzyme Photosystem II in general, and of the oxygen-evolving manganese-calcium cluster at its active site in particular. Here we review the most important aspects of biological water oxidation, emphasizing current knowledge on the organization of the enzyme, the geometric and electronic structure of the catalyst, and the role of calcium and chloride cofactors. The combination of recent experimental work on the identification of possible substrate sites with computational modeling have considerably limited the possible mechanistic pathways for the critical O-O bond formation step. Taken together, the key features and principles of natural photosynthesis may serve as inspiration for the design, development, and implementation of artificial systems. PMID:26099285

  13. The primary steps of photosynthesis

    International Nuclear Information System (INIS)

    The two important initial steps of photosynthesis-electron transfer and energy transfer occur with great speed and efficiency. New techniques in laser optics and genetic engineering age helping us to understand why. (author). 24 refs. 8 figs

  14. Growth and photosynthesis of lettuce

    OpenAIRE

    Holsteijn, van, H.M.C.

    1981-01-01

    Butterhead lettuce is an important glass-house crop in the poor light period in The Netherlands. Fundamental data about the influence of temperature, light and CO 2 on growth and photosynthesis are important e.g. to facilitate selection criteria for new cultivars. In this study on lettuce emphasis has been given to light interception in the poor light period, the relationship of growth rate and relative growth rate with time, dry weight and soil cover, and to photosynthesis properties of the ...

  15. Modeling the protection of photosynthesis

    OpenAIRE

    Harbinson, J.

    2012-01-01

    It is hard to overstate the importance of photosynthesis for mankind and the biosphere. It produces the oxygen we breathe and the food we eat, and images of Earth from space show the green of terrestrial vegetation and swirls of marine phytoplankton. To meet our increasing demand for food and energy, it seems inevitable that we will need to increase the efficiency of photosynthesis in plants and algae. There is therefore some urgency in our drive to better understand the operation, regulation...

  16. Photosynthesis: From Natural Towards Artificial

    OpenAIRE

    Chow, W.S.

    2003-01-01

    Photosynthesis, the natural process that yields food, fuel and fibre, spans physical and biological sciences, spatially from atomic scales to the global and temporally from electronic transitions to the evolutionary time frame. Photosynthesis is highly efficient in its primary energy capture, but much less so in terms of conversion to crop yield. The natural photosynthetic system provides fertile ground for exploring and dissecting partial processes that may be mimicked inartificial systems f...

  17. Dark states in quantum photosynthesis

    CERN Document Server

    Kozyrev, S V

    2016-01-01

    We discuss a model of quantum photosynthesis with degeneracy in the light-harvesting system. We consider interaction of excitons in chromophores with light and phonons (vibrations of environment). These interactions have dipole form but are different (are related to non-parallel vectors of "bright" states). We show that this leads to excitation of non-decaying "dark" states. We discuss relation of this model to the known from spectroscopical experiments phenomenon of existence of photonic echo in quantum photosynthesis.

  18. Prokaryotic photosynthesis and phototrophy illuminated

    DEFF Research Database (Denmark)

    Bryant, Donald A; Frigaard, Niels-Ulrik

    2006-01-01

    Genome sequencing projects are revealing new information about the distribution and evolution of photosynthesis and phototrophy. Although coverage of the five phyla containing photosynthetic prokaryotes (Chlorobi, Chloroflexi, Cyanobacteria, Proteobacteria and Firmicutes) is limited and uneven......, genome sequences are (or soon will be) available for >100 strains from these phyla. Present knowledge of photosynthesis is almost exclusively based on data derived from cultivated species but metagenomic studies can reveal new organisms with novel combinations of photosynthetic and phototrophic...

  19. Hazmat Cam Wireless Video System

    Energy Technology Data Exchange (ETDEWEB)

    Kevin L. Young

    2006-02-01

    This paper describes the Hazmat Cam Wireless Video System and its application to emergency response involving chemical, biological or radiological contamination. The Idaho National Laboratory designed the Hazmat Cam Wireless Video System to assist the National Guard Weapons of Mass Destruction - Civil Support Teams during their mission of emergency response to incidents involving weapons of mass destruction. The lightweight, handheld camera transmits encrypted, real-time video from inside a contaminated area, or hot-zone, to a command post located a safe distance away. The system includes a small wireless video camera, a true-diversity receiver, viewing console, and an optional extension link that allows the command post to be placed up to five miles from danger. It can be fully deployed by one person in a standalone configuration in less than 10 minutes. The complete system is battery powered. Each rechargeable camera battery powers the camera for 3 hours with the receiver and video monitor battery lasting 22 hours on a single charge. The camera transmits encrypted, low frequency analog video signals to a true-diversity receiver with three antennas. This unique combination of encryption and transmission technologies delivers encrypted, interference-free images to the command post under conditions where other wireless systems fail. The lightweight camera is completely waterproof for quick and easy decontamination after use. The Hazmat Cam Wireless Video System is currently being used by several National Guard Teams, the US Army, and by fire fighters. The system has been proven to greatly enhance situational awareness during the crucial, initial phase of a hazardous response allowing commanders to make better, faster, safer decisions.

  20. CAD/CAM-prosessin kuvaus

    OpenAIRE

    Aho, Arto

    2014-01-01

    Työssä selvitettiin CAD/CAM-prosessin toiminta ja datan liikkuminen eri järjestelmien välillä. Teoriassa perehdyttiin tuotetietojen ja muutostenhallintaan sekä järjestelmien integrointiin. Siemens PLM -järjestelmästä esitellään valmistusprosessin suunnitteluun ja hallintaan tarkoitettuja sovelluksia. Työssä käsitellään muutoksenhallintaa järjestelmien välillä sekä nopeiden muutosten aikaansaamat hyödyt prosessissa ja integraation tuomat edut virheiden ja kustannusten vähentämisessä. Työssä...

  1. CAD/CAM-ohjelmiston valinta

    OpenAIRE

    Heino, Sanna

    2011-01-01

    Opinnäytetyön toimeksianto tuli Helasteel Oy:ltä. Työn sisältö koostuu sopivan CAM-ohjelmiston etsimisestä Helasteelille sekä niiden perusteiden selvittämisestä, jotka vaikuttavat ohjelmiston valintaan. Kolmea eri ohjelmistotoimittajaa pyydettiin esittelemään tuotteitaan Helasteelille. Näistä ohjelmistoista valittiin sopivin yrityksen työstämät kappaleet ja tuotanto huomioon ottaen. Prosessin jälkeen päädyttiin Wincam-ohjelmistoon, joka vastasi parhaiten Helasteelin vaatimuksiin niin omina...

  2. Thyroid Disease and Complementary and Alternative Medicine (CAM)

    Science.gov (United States)

    ... to Donate Thyroid Disease and Complementary and Alternative Medicine (CAM) WHAT IS A THYROID NODULE? The term ... type of evaluation. WHAT IS COMPLEMENTARY AND ALTERNATIVE MEDICINE (CAM)? Complementary and Alternative Medicine (CAM) is defined ...

  3. Differential responses of C3 and CAM native Brazilian plant species to a SO2- and SPMFe-contaminated Restinga.

    Science.gov (United States)

    da Silva, Luzimar Campos; de Araújo, Talita Oliveira; Martinez, Carlos Alberto; de Almeida Lobo, Francisco; Azevedo, Aristéa Alves; Oliva, Marco Antonio

    2015-09-01

    Aiming to evaluate responses in terms of growth rates, physiological parameters, and degree of sensitivity to SO2 and SPMFe in Eugenia uniflora L. (Myrtaceae, a C3 species) and Clusia hilariana Schlecht (Clusiaceae, a CAM species); saplings were exposed to emissions from a pelletizing factory for 7 months. The species were distributed along a transect (200, 500, 800, 1400, and 1700 m away from the emission source), and analyses were performed after 71, 118, and 211 days of exposure to the pollutants. E. uniflora received higher superficial deposition of particulate iron. The highest total iron foliar contents were observed 200 m away from the emission source in both plant species, while the highest total sulfur foliar contents were observed 200 m away in C. hilariana and 800 m away in E. uniflora. E. uniflora presented decreased values of height growth rate, number of necrotic leaves, chlorophyll analysis (SPAD index) and transpiration, in relation to the distances from the emission source. C. hilariana showed decreased values of height growth rate, number of leaves, number of necrotic leaves, total ionic permeability, stomatal conductance, transpiration, net CO2 assimilation, and total dry matter, in relation to distances from the emission source. In relation to the days of exposure, both species presented increased number of necrotic leaves and foliar phytotoxicity index, and decreased values in the chlorophyll analysis. The two native plant species, both of which occur in the Brazilian Restinga, showed damage when exposed to emissions from an iron ore pelletizing factory. C. hilariana was considered the most sensitive species due to the decreased values in a higher number of variables after exposition. PMID:25956514

  4. RESEARCH ON STRAIGHTENING TECHNOLOGY CAM SYSTEM

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Automatic straightening process is a nonlinear process, and affected by many factors.The straightening technology CAM system has been designed and built up to straighten shafts, which mainly consists of the straightening technology's database and the model of stroke-controlled precise straightening calculation model.The operational test of the CAM system has been passed.

  5. Impact of the cam and follower cooperation and of lubrication on the cam wear

    Directory of Open Access Journals (Sweden)

    P. Folęga

    2012-12-01

    Full Text Available Purpose: The paper provides an analysis of the reasons for excessive wear of the cam/follower system components based on physical and mathematical models developed to describe the impact of selected material, technological and operational factors. Owing to the comparison between the calculation results obtained and the actual cam wear values, it was possible to asses the correctness of the wear models taken into consideration.Design/methodology/approach: The research in question included preparation of a mathematical cam wear model developed by way of dimensional analysis as well as finite element (FEM based structural models for a cam/follower system. The aforementioned FEM models were noted in a parametrical form using macro commands of the COSMOS/M system, and hence it was possible to analyse contact problems in various cam positions and change the selected analytical parameters (e.g. dimensions, material parameters.Findings: The main reasons for excessive cam wear include inferior quality of the cam and follower frictional couple lubrication as well as edge-type cooperation between the cam and the cam follower. At the same time, a significant impact on the wear is exerted by hardness of the cam and its follower.Research limitations/implications: Wear of cams and cam followers operating in timing gear systems of vehicle combustion engines takes place as an effect of friction occurring in presence of lubricant. During standard operation, components of the cam/follower system may be subject to an excessive or accelerated wear process. This study is an attempt to establish the reasons for this phenomenon to occur in order to control such cases.Originality/value: In order to counteract the phenomenon of accelerated wear of cams, one should consider increasing the required hardness of their working surfaces.

  6. Community photosynthesis of aquatic macrophytes

    DEFF Research Database (Denmark)

    Binzer, T.; Sand-Jensen, K.; Middelboe, A. L.

    2006-01-01

    We compared 190 photosynthesis-irradiance (P-E) experiments with single- and multispecies communities of macroalgae and vascular plants from freshwater and marine habitats. We found a typical hyperbolic P-E relation in all communities and no sign of photosaturation or photoinhibition of photosynt......We compared 190 photosynthesis-irradiance (P-E) experiments with single- and multispecies communities of macroalgae and vascular plants from freshwater and marine habitats. We found a typical hyperbolic P-E relation in all communities and no sign of photosaturation or photoinhibition of...... photosynthesis at the highest irradiances of about 2,000 mmol m22 s21. Macrophyte communities displayed much higher maximum gross production (GPmax), respiration, and light compensation point than separate phytoelements because of the multilayered structure and extensive self-shading in the communities, whereas...

  7. Techniques in studies of photosynthesis

    International Nuclear Information System (INIS)

    The use of both stable and radioactive isotopes has led to major advances in the understanding of the basic mechanisms of photosynthesis. An early use of isotopic material in photosynthetic investigations was the demonstration using 18O, that O2 evolved in photosynthesis was derived from water rather than from CO2. When the long-lived isotope of carbon, 14C, became available in 1945, its use, coupled with two-dimensional chromatography developed a few years earlier, enabled Calvin and Benson (1948) to devise experiments to elucidate the pathway of photosynthetic 14CO2 fixation, 12 refs, 6 figs, 10 tabs

  8. Cad/cam-tekniikan kannattavuus hammastekniikassa

    OpenAIRE

    Kinnunen, Vilho

    2012-01-01

    Hammaslaboratorioissa tehdään cad/cam-tekniikalla kiinteän protetiikan töitä. Opinnäytetyössäni tarkastelen, kuinka kannattavaa on valmistaa jyrsintekniikalla kiinteän protetiikan valmisteita. Selvitän millainen cad/cam-tekniikkaa käyttävä yritys pitää olla, jotta se on kannattava. Opinnäytetyöni aineiston keruun tein haastattelemalla cad/cam tekniikkaa ja perinteistä tekniikkaa käyttävien hammaslaboratorioiden omistajia. Haastattelun toteutin teemahaastatteluna. Kehitin laajuuskäsitteen,...

  9. CAM Stochastic Volatility Model for Option Pricing

    Directory of Open Access Journals (Sweden)

    Wanwan Huang

    2016-01-01

    Full Text Available The coupled additive and multiplicative (CAM noises model is a stochastic volatility model for derivative pricing. Unlike the other stochastic volatility models in the literature, the CAM model uses two Brownian motions, one multiplicative and one additive, to model the volatility process. We provide empirical evidence that suggests a nontrivial relationship between the kurtosis and skewness of asset prices and that the CAM model is able to capture this relationship, whereas the traditional stochastic volatility models cannot. We introduce a control variate method and Monte Carlo estimators for some of the sensitivities (Greeks of the model. We also derive an approximation for the characteristic function of the model.

  10. The Path of Carbon in Photosynthesis VI.

    Science.gov (United States)

    Calvin, M.

    1949-06-30

    This paper is a compilation of the essential results of our experimental work in the determination of the path of carbon in photosynthesis. There are discussions of the dark fixation of photosynthesis and methods of separation and identification including paper chromatography and radioautography. The definition of the path of carbon in photosynthesis by the distribution of radioactivity within the compounds is described.

  11. Growth and photosynthesis of lettuce

    NARCIS (Netherlands)

    Holsteijn, van H.M.C.

    1981-01-01

    Butterhead lettuce is an important glass-house crop in the poor light period in The Netherlands. Fundamental data about the influence of temperature, light and CO 2 on growth and photosynthesis are important e.g. to facilitate selection criteria for new cultivars. In this study on lettuce

  12. How carotenoids protect bacterial photosynthesis.

    OpenAIRE

    Cogdell, R J; Howard, T. D.; Bittl, R.; Schlodder, E; Geisenheimer, I; Lubitz, W.

    2000-01-01

    The essential function of carotenoids in photosynthesis is to act as photoprotective agents, preventing chlorophylls and bacteriochlorophylls from sensitizing harmful photodestructive reactions in the presence of oxygen. Based upon recent structural studies on reaction centres and antenna complexes from purple photosynthetic bacteria, the detailed organization of the carotenoids is described. Then with specific reference to bacterial antenna complexes the details of the photoprotective role, ...

  13. Chlorophylls, Symmetry, Chirality, and Photosynthesis.

    OpenAIRE

    Mathias O. Senge; Aoife A. Ryan; Kristie A. Letchford; Stuart A. MacGowan; Tamara Mielke

    2014-01-01

    Chlorophylls are a fundamental class of tetrapyrroles and function as the central reaction center, accessory and photoprotective pigments in photosynthesis. Their unique individual photochemical properties are a consequence of the tetrapyrrole macrocycle, the structural chemistry and coordination behavior of the phytochlorin system, and specific substituent pattern. They achieve their full potential in solar energy conversion by working in concert in highly complex, supramolecular structures ...

  14. Studying Photosynthesis by Measuring Fluorescence

    Science.gov (United States)

    Sanchez, Jose Francisco; Quiles, Maria Jose

    2006-01-01

    This paper describes an easy experiment to study the absorption and action spectrum of photosynthesis, as well as the inhibition by heat, high light intensity and the presence of the herbicide 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) on the photosynthetic process. The method involves measuring the chlorophyll fluorescence emitted by intact…

  15. Assessing Photosynthesis by Fluorescence Imaging

    Science.gov (United States)

    Saura, Pedro; Quiles, Maria Jose

    2011-01-01

    This practical paper describes a novel fluorescence imaging experiment to study the three processes of photochemistry, fluorescence and thermal energy dissipation, which compete during the dissipation of excitation energy in photosynthesis. The technique represents a non-invasive tool for revealing and understanding the spatial heterogeneity in…

  16. Injecting Inquiry into Photosynthesis Investigations

    Science.gov (United States)

    Salter, Irene; Smith, Rebecca; Nielsen, Katherine

    2008-01-01

    This is the story of how a typical middle school lab was transformed into an open-ended inquiry experience through a few small, but very powerful, changes. By allowing students to follow their own questions, the classroom filled with enthusiasm and students learned much more about photosynthesis, respiration, and the scientific processes. The…

  17. Vertical distribution of pelagic photosynthesis

    DEFF Research Database (Denmark)

    Lyngsgaard, Maren Moltke

    As phytoplankton photosynthesis is dependent on light, one might assume that all the phytoplankton activity occurs in the surface of our oceans. This assumption was, however, challenged early in the history of biological oceanography when chlorophyll sampling and fluorescence profiling showed deep...

  18. A CAD/CAM interface for computer-aided design of cams

    OpenAIRE

    Gandhi, Ashit R.

    1985-01-01

    The purpose of this thesis is to provide a complete package for the design and three dimensional modeling display of cams. The software produced as a part of this work will operate as a module of CADAM to produce cam designs and enter the resulting cam as a CAD model and produce the graphical display of the cam. In addition to the introductory material, this thesis is divided into four sections. The section on the graphics packages used in this thesis includes a b...

  19. AFSC/FMA/CAMS Data Objects

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The CAMS system consists of a set of tables and packages that provide authentication services to all other North Pacific Groundfish and Halibut Observing Program...

  20. Model Documentation for the MiniCAM

    Energy Technology Data Exchange (ETDEWEB)

    Brenkert, Antoinette L.; Smith, Steven J.; Kim, Son H.; Pitcher, Hugh M.

    2003-07-17

    The MiniCAM, short for the Mini-Climate Assessment Model, is an integrated assessment model of moderate complexity focused on energy and agriculture sectors. The model produces emissions of greenhouse gases (carbon dioxide, methane and nitrous oxide) and other radiatively important substances such as sulfur dioxide. Through incorporation of the simple climate model MAGICC, the consequences of these emissions for climate change and sea-level rise can be examined. The MiniCAM is designed to be fast and flexible.

  1. Radiometric Calibration for AgCam

    OpenAIRE

    Edward Hildum; Lianbo Hu; Hojin Kim; Xiaodong Zhang; Changyong Dou; Doug Olsen

    2010-01-01

    The student-built Agricultural Camera (AgCam) now onboard the International Space Station observes the Earth surface through two linescan cameras with Charge-Coupled Device (CCD) arrays sensitive to visible and near-infrared wavelengths, respectively. The electro-optical components of the AgCam were characterized using precision calibration equipment; a method for modeling and applying these measurements was derived. Correction coefficients to minimize effects of optical vignetting, CCD non-u...

  2. CAM and stack air sampler design guide

    International Nuclear Information System (INIS)

    About 128 air samplers and CAMs presently in service to detect and document potential radioactive release from 'H' and 'F' area tank farm ventilation stacks are scheduled for replacement and/or upgrade by Projects S-5764, S-2081, S-3603, and S-4516. The seven CAMs scheduled to be upgraded by Project S-4516 during 1995 are expected to provide valuable experience for the three remaining projects. The attached document provides design guidance for the standardized High Level Waste air sampling system

  3. Statistical Shape Modeling of Cam Femoroacetabular Impingement

    Energy Technology Data Exchange (ETDEWEB)

    Harris, Michael D.; Dater, Manasi; Whitaker, Ross; Jurrus, Elizabeth R.; Peters, Christopher L.; Anderson, Andrew E.

    2013-10-01

    In this study, statistical shape modeling (SSM) was used to quantify three-dimensional (3D) variation and morphologic differences between femurs with and without cam femoroacetabular impingement (FAI). 3D surfaces were generated from CT scans of femurs from 41 controls and 30 cam FAI patients. SSM correspondence particles were optimally positioned on each surface using a gradient descent energy function. Mean shapes for control and patient groups were defined from the resulting particle configurations. Morphological differences between group mean shapes and between the control mean and individual patients were calculated. Principal component analysis was used to describe anatomical variation present in both groups. The first 6 modes (or principal components) captured statistically significant shape variations, which comprised 84% of cumulative variation among the femurs. Shape variation was greatest in femoral offset, greater trochanter height, and the head-neck junction. The mean cam femur shape protruded above the control mean by a maximum of 3.3 mm with sustained protrusions of 2.5-3.0 mm along the anterolateral head-neck junction and distally along the anterior neck, corresponding well with reported cam lesion locations and soft-tissue damage. This study provides initial evidence that SSM can describe variations in femoral morphology in both controls and cam FAI patients and may be useful for developing new measurements of pathological anatomy. SSM may also be applied to characterize cam FAI severity and provide templates to guide patient-specific surgical resection of bone.

  4. Chiropractic and CAM Utilization: A Descriptive Review

    Directory of Open Access Journals (Sweden)

    Meeker William C

    2007-01-01

    Full Text Available Abstract Objective To conduct a descriptive review of the scientific literature examining use rates of modalities and procedures used by CAM clinicians to manage chronic LBP and other conditions Data Sources A literature of PubMed and MANTIS was performed using the key terms Chiropractic; Low Back Pain; Utilization Rate; Use Rate; Complementary and Alternative Medicine; and Health Services in various combinations. Data Selection A total of 137 papers were selected, based upon including information about chiropractic utilization, CAM utilization and low back pain and other conditions. Data Synthesis Information was extracted from each paper addressing use of chiropractic and CAM, and is summarized in tabular form. Results Thematic analysis of the paper topics indicated that there were 5 functional areas covered by the literature: back pain papers, general chiropractic papers, insurance-related papers, general CAM-related papers; and worker's compensation papers. Conclusion Studies looking at chiropractic utilization demonstrate that the rates vary, but generally fall into a range from around 6% to 12% of the population, most of whom seek chiropractic care for low back pain and not for organic disease or visceral dysfunction. CAM is itself used by people suffering from a variety of conditions, though it is often used not as a primary intervention, but rather as an additional form of care. CAM and chiropractic often offer lower costs for comparable results compared to conventional medicine.

  5. A NEW CONCEPT OF PHOTOSYNTHESIS

    OpenAIRE

    Komissarov, Gennadiy

    2014-01-01

    The history of the formation of a new concept of photosynthesis proposed by the author is considered for the period since 1966 to 2013. Its essence consists in the following facts: the photosynthetic oxygen (hydrogen) source is not water, but exoand endogenous hydrogen peroxide; thermal energy is a necessary part of the photosynthetic process; along with the carbon dioxide the air (oxygen, inert gases) is included in the photosynthetic equation. The mechanism of the photovoltaic (Becquerel) e...

  6. Characterization of SynCAM surface trafficking using a SynCAM derived ligand with high homophilic binding affinity

    International Nuclear Information System (INIS)

    In order to better probe SynCAM function in neurons, we produced a fusion protein between the extracellular domain of SynCAM1 and the constant fragment of human IgG (SynCAM-Fc). Whether in soluble form or immobilized on latex microspheres, the chimera bound specifically to the surface of hippocampal neurons and recruited endogenous SynCAM molecules. SynCAM-Fc was also used in combination with Quantum Dots to follow the mobility of transfected SynCAM receptors at the neuronal surface. Both immobile and highly mobile SynCAM were found. Thus, SynCAM-Fc behaves as a high affinity ligand that can be used to study the function of SynCAM at the neuronal membrane

  7. BOOK REVIEW. Photosynthesis in the Marine Environment

    OpenAIRE

    Arthur Grossman

    2015-01-01

    Photosynthesis in the Marine Environment was written by three experienced marine biologists, Sven Beer, Mats Björk, and John Beardall, who have all worked for many years on photosynthesis and the utilization of inorganic carbon in the marine environment. They have published numerous papers dealing with photosynthesis and the fixation of inorganic carbon by various marine organisms, including seagrasses, macroalgae, and microalgae, and how the environment impacts their photosynthetic activity....

  8. Global Analysis of Photosynthesis Transcriptional Regulatory Networks

    OpenAIRE

    Imam, Saheed; Noguera, Daniel R.; Donohue, Timothy J.

    2014-01-01

    Photosynthesis is a crucial biological process that depends on the interplay of many components. This work analyzed the gene targets for 4 transcription factors: FnrL, PrrA, CrpK and MppG (RSP_2888), which are known or predicted to control photosynthesis in Rhodobacter sphaeroides. Chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-seq) identified 52 operons under direct control of FnrL, illustrating its regulatory role in photosynthesis, iron homeostasis, nitrogen met...

  9. Global analysis of photosynthesis transcriptional regulatory networks.

    OpenAIRE

    Saheed Imam; Noguera, Daniel R.; Donohue, Timothy J.

    2014-01-01

    Photosynthesis is a crucial biological process that depends on the interplay of many components. This work analyzed the gene targets for 4 transcription factors: FnrL, PrrA, CrpK and MppG (RSP_2888), which are known or predicted to control photosynthesis in Rhodobacter sphaeroides. Chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-seq) identified 52 operons under direct control of FnrL, illustrating its regulatory role in photosynthesis, iron homeostasis, nitrogen met...

  10. Photosynthesis for Food, Fuel and the Future

    Institute of Scientific and Technical Information of China (English)

    Congming Lu

    2010-01-01

    @@ Photosynthesis is a process that converts solar energy to chemical energy in many different organisms, ranging from plants to bacteria. Photosynthesis provides all the food we eat and all the fossil fuel we use. Photosynthesis has long been studied in order to understand its underlying mechanisms and then to apply this knowledge to the production of energy and food for the needs of our society.

  11. Understanding of photosynthesis among primary school pupils

    OpenAIRE

    Murn, Špela

    2014-01-01

    Photosynthesis is considered one of the most difficult subjects for pupils. It is very complex topic, which is very difficult to understand. The goal of our research was to examine the knowledge on photosynthesis of the pupils of the primary school, their attitude towrds it, and whether there were any misconceptions about photosynthesis. The research was conducted on a sample of 120 pupils in Dolenjske Toplice primary school. The questionnaire consisted of 19 questions. In the first part o...

  12. MEASUREMENT AND MODELLING AVERAGE PHOTOSYNTHESIS OF MAIZE

    OpenAIRE

    ZS LÕKE

    2005-01-01

    The photosynthesis of fully developed maize was investigated in the Agrometeorological Research Station Keszthely, in 2000. We used LI-6400 type measurement equipment to locate measurement points where the intensity of photosynthesis mostly nears the average. So later we could obtain average photosynthetic activities featuring the crop, with only one measurement. To check average photosynthesis of maize we used Goudriaan’s simulation model (CMSM) as well to calculate values on cloudless sampl...

  13. CAM practitioners in the Australian health workforce: an underutilized resource

    Directory of Open Access Journals (Sweden)

    Grace Sandra

    2012-11-01

    Full Text Available Abstract Background CAM practitioners are a valuable but underutilizes resource in Australian health care. Despite increasing public support for complementary and alternative medicine (CAM little is known about the CAM workforce. Apart from the registered professions of chiropractic, osteopathy and Chinese medicine, accurate information about the number of CAM practitioners in the workforce has been difficult to obtain. It appears that many non-registered CAM practitioners, although highly qualified, are not working to their full capacity. Discussion Increasing public endorsement of CAM stands in contrast to the negative attitude toward the CAM workforce by some members of the medical and other health professions and by government policy makers. The marginalisation of the CAM workforce is evident in prejudicial attitudes held by some members of the medical and other health professions and its exclusion from government policy making. Inconsistent educational standards has meant that non-registered CAM practitioners, including highly qualified and competent ones, are frequently overlooked. Legitimising their contribution to the health workforce could alleviate workforce shortages and provide opportunities for redesigned job roles and new multidisciplinary teams. Priorities for better utilisation of the CAM workforce include establishing a guaranteed minimum education standard for more CAM occupation groups through national registration, providing interprofessional education that includes CAM practitioners, developing courses to upgrade CAM practitioners' professional skills in areas of indentified need, and increasing support for CAM research. Summary Marginalisation of the CAM workforce has disadvantaged those qualified and competent CAM practitioners who practise evidence-informed medicine on the basis of many years of university training. Legitimising and expanding the important contribution of CAM practitioners could alleviate projected health

  14. Patients’ views of CAM as spiritual practice

    DEFF Research Database (Denmark)

    Ulrich, Anita; Evron, Lotte; Ostenfeld-Rosenthal, Ann

    2011-01-01

    Objectives: This paper explores Danish cancer patients’ narratives on spiritual beliefs, practices and the relationship these practices may have to complementary and alternative medicine (CAM). Design: Narrative inquiry was used to understand how spiritual beliefs and practices might be related...... to CAM. Thirty-two cancer patients, family, friends and alternative practitioners were followed up over a two year period by face to face interview, telephone and focus groups. Results: Although religious and spiritual issues were not manifestly expressed by many of the subjects, these issues were...... significantly elaborated upon in narratives by four female participants to warrant more detailed consideration and analysis. Conclusion: It is suggested that for some cancer patients CAM may function, not just as a treatment for cancer related symptoms and side effects, but also as a form of spiritual practice...

  15. Estrutura do estrato herbáceo na formação aberta de Clusia do Parque Nacional da Restinga de Jurubatiba, RJ, Brasil Herb layer structure of Clusia scrub in the Restinga de Jurubatiba National Park, Rio de Janeiro, Brazil

    Directory of Open Access Journals (Sweden)

    Miriam Cristina Alvarez Pereira

    2004-09-01

    Full Text Available No Parque Nacional da Restinga de Jurubatiba localiza-se o site 5 do Programa de Pesquisas Ecológicas de Longa Duração (PELD, região de grande diversidade de hábitats e riqueza florística nas restingas do Norte do Estado do Rio de Janeiro. Para descrever a composição florística e estrutura do estrato herbáceo da formação aberta de Clusia foram amostrados todos os indivíduos deste estrato utilizando-se o método de parcelas. Em três diferentes áreas foram distribuídos 200 quadrados de 1m², totalizando 600m². Em cada quadrado anotou-se o número de indivíduos e percentagem de cobertura de cada espécie. Para a comparação entre as áreas utilizaram-se os índices de Similaridade de Sørensen, diversidade de Shannon (H' e equabilidade de Pielou (J'. Foram amostrados 39 espécies e 3.021 indivíduos. Allagoptera arenaria (Gomes Kuntze, Vriesea neoglutinosa Mez, Aechmea nudicaulis (L. Griseb., Stigmaphyllon paralias A. Juss., Neoregelia cruenta (Graham L.B. Sm., Anthurium maricense Nadruz & Mayo, Pilosocereus arrabidae (Lem. Byles & G.D. Rowl. e Ipomoea imperati (Vahl Griseb. obtiveram os maiores valores de importância. A diversidade foi H'=1,89 nats/m² e a equabilidade J'= 0,52, utilizando a cobertura como medida de abundância das espécies por esta evitar a subjetividade na definição de indivíduos e melhor representar a estrutura oligárquica aqui descrita. O ponto A diferencia-se significativamente de B e C quanto ao número de indivíduos e à cobertura vegetal herbácea. O número de espécies e os índices de diversidade não apresentaram diferenças significativas. Os resultados aqui apresentados diferem parcialmente dos obtidos anteriormente para o estrato arbustivo, sugerindo que estudos sobre distribuição espacial e associação entre espécies são necessários para esclarecer as relações entre estes dois estratos.Long Term Ecological Research (LTER Site No.5 in the Restinga de Jurubatiba National Park

  16. Artificial intelligence and CAD/CAM

    Energy Technology Data Exchange (ETDEWEB)

    Iwata, K.

    1983-10-01

    In recent years CAD/CAM technology has improved industrial productivity. It is a significant step towards the design of the factory of the future. CAD/CAM in conjunction with artificial intelligence will become paramount. Workers in this field are attempting to produce systems of ever-increasing intelligence and independence for everyday use in factories, schools and elsewhere. A computer system which could understand natural language in both spoken and handwritten form and communicate in natural language would have considerable advantage in practical situations over one of the present generation of computers and computer programs. 2 references.

  17. CAD/CAM at the design stage

    Energy Technology Data Exchange (ETDEWEB)

    Masur, W.

    1989-01-01

    The introduction of CAD/CAM requires a thorough analysis of the manufacturing process in order to be able to single out those operations and partial complexes which are found suited for CAD/CAM use and are also expected to bring about the streamlining effects desired. Further it has to be analysed what partial jobs can be done by existing and planned hardware and software as well as by the skilled labour available or to be made available yet. The organization of the relations between program developer and program user and the required training measures has to be fixed in time and clearly by the managerial staff.

  18. General lighting requirements for photosynthesis

    Science.gov (United States)

    Geiger, Donald R.

    1994-01-01

    This paper presents data that suggests some criteria for evaluating growth chamber and greenhouse lighting. A review of the general lighting requirements for photosynthesis reveals that four aspects of light are important: irradiance, quality, timing, and duration. Effective lighting should produce plants that perform according to the goals of the project. For example, for physiological studies the plants probably should exhibit morphology and physiology similar to that found in field-grown plants. For other projects the criteria will obviously be set according to the reason for raising the plants.

  19. Integrated design of cam mechanisms and servo-control systems

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Traditionally, in a cam mechanism, the cam is driven by an actuator at a constant speed. The motion characteristics of the follower are determined once the cam profile is designed. This paper presents a novel theory named "integrated design of cam mechanisms and servo-control systems" whose basic idea is varying the input speed trajectory of the cam by a microcomputer-controlled servomotor to improve kinematic and dynamic characteristics of the follower system. The philosophy of the theory is developing superior machines by taking advantage of the flexibility of servo-control systems to compensate for disadvantages of rigid cam mechanisms. The systematic design criteria of the cam-servo-integrated system are developed and an approach based on optimal-control theory is presented for to select suitable cam speed functions, hence the basis of the theory is formed.

  20. Parametric Modeling for Globoidal Cam Based and NC Machining

    OpenAIRE

    Haitao Liu; Zhibin Chang; Lei Zhang; Wei Jiang; Guangguo Zhang

    2013-01-01

    The design and machining of globoidal cam is difficult, because the shape of working surface is complex,and the curved surface of its space is undevelopable. Based on the above reasons,we proposed the parametric Modeling method for globoidal cam based. Through the secondary development, we realized the parameterized modeling of globoidal cam. Base on using of globular indexing cam NC milling machine existing in the lab,research the programming technology,analyses the defects of conventional p...

  1. DFM/CAPP/CAM System in a Concurrent Engineering Environment

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    In this paper the importance of DFM/CAPP/CAM system in Concurrent Engineering (CE) is discussed. Based on the analyses of the character of concurrent product design and manufacturing process design, the workflow of DFM/CAPP/CAM system in CE is given. DFM/CAPP/CAM theories, methods and functions are investigated in a delicate and all-round way, and are implemented in the developed DFM/CAPP/CAM system.

  2. Photochemistry and enzymology of photosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Radmer, R.

    1979-07-30

    In the first task, a specially designed mass spectrometer system monitors the gas exchange occurring in response to single short flashes of light. This apparatus will be primarily used to study photosystem II donor reactions, such as the photooxidation of hydroxylamine, hydrazine, and hydrogen peroxide. This technique will also be used to study the light-induced exchange of O/sub 2/ and CO/sub 2/ in algae. The second task, biochemical studies, will focus on the role of chloroplast copper in photosynthesis. We propose to isolate, purify, and characterize the chloroplast copper enzyme polyphenol oxidase, and attempt to elucidate its role in photosynthesis. These studies will be integrated with a new program devoted to the biochemical response of the photosynthetic membrane to stress. The third task is a series of studies on the light-harvesting and electron-transport mechanisms of C/sub 4/ plants. This program will address three basic problems: (1) the effect of different preparative procedures on various photosynthetic reactions, with particular emphasis on photosystem II reactions in corn bundle sheath chloroplasts; (2) the development and testing of photosystem II assays; and (3) studies of the stoichiometry of electron carriers in bundle sheath chloroplasts, and whether cyclic phosphorylation could be a major pathway in this tissue.

  3. Chlorophylls, Symmetry, Chirality, and Photosynthesis

    Directory of Open Access Journals (Sweden)

    Mathias O. Senge

    2014-09-01

    Full Text Available Chlorophylls are a fundamental class of tetrapyrroles and function as the central reaction center, accessory and photoprotective pigments in photosynthesis. Their unique individual photochemical properties are a consequence of the tetrapyrrole macrocycle, the structural chemistry and coordination behavior of the phytochlorin system, and specific substituent pattern. They achieve their full potential in solar energy conversion by working in concert in highly complex, supramolecular structures such as the reaction centers and light-harvesting complexes of photobiology. The biochemical function of these structures depends on the controlled interplay of structural and functional principles of the apoprotein and pigment cofactors. Chlorophylls and bacteriochlorophylls are optically active molecules with several chiral centers, which are necessary for their natural biological function and the assembly of their supramolecular complexes. However, in many cases the exact role of chromophore stereochemistry in the biological context is unknown. This review gives an overview of chlorophyll research in terms of basic function, biosynthesis and their functional and structural role in photosynthesis. It highlights aspects of chirality and symmetry of chlorophylls to elicit further interest in their role in nature.

  4. CAD/CAM. High-Technology Training Module.

    Science.gov (United States)

    Zuleger, Robert

    This high technology training module is an advanced course on computer-assisted design/computer-assisted manufacturing (CAD/CAM) for grades 11 and 12. This unit, to be used with students in advanced drafting courses, introduces the concept of CAD/CAM. The content outline includes the following seven sections: (1) CAD/CAM software; (2) computer…

  5. Therapeutic Uses of the WebCam in Child Psychiatry

    Science.gov (United States)

    Chlebowski, Susan; Fremont, Wanda

    2011-01-01

    Objective: The authors provide examples for the use of the WebCam as a therapeutic tool in child psychiatry, discussing cases to demonstrate the application of the WebCam, which is most often used in psychiatry training programs during resident supervision and for case presentations. Method: Six cases illustrate the use of the WebCam in individual…

  6. The factors that influence CAD/CAM/CAE

    International Nuclear Information System (INIS)

    CAD/CAM/CAE usage has grown and expanded significantly due to its many applications relating to the productivity of an organization. It is important for an organization to have planning and strategy in using CAD/CAM/CAE to ensure sustained efficiency. This paper will discuss the factors that can influence the implementation and success of CAD/CAM/CAE. (Author)

  7. Photosynthesis: The Path of Carbon in Photosynthesis and the Primary Quantum Conversion Act of Photosynthesis

    Science.gov (United States)

    Calvin, Melvin

    1952-11-22

    This constitutes a review of the path of carbon in photosynthesis as it has been elaborated through the summer of 1952, with particular attention focused on those aspects of carbon metabolism and its variation which have led to some direct information regarding the primary quantum conversion act. An introduction to the arguments which have been adduced in support of the idea that chlorophyll is a physical sensitizer handing its excitation on to thioctic acid, a compound containing a strained 1, 2 -dithiolcyclopentane ring, is given.

  8. Photosynthesis and Respiration in a Jar.

    Science.gov (United States)

    Buttner, Joseph K.

    2000-01-01

    Describes an activity that reduces the biosphere to a water-filled jar to simulate the relationship between cellular respiration, photosynthesis, and energy. Allows students in high school biology and related courses to explore quantitatively cellular respiration and photosynthesis in almost any laboratory setting. (ASK)

  9. Modelling Photosynthesis to Increase Conceptual Understanding

    Science.gov (United States)

    Ross, Pauline; Tronson, Deidre; Ritchie, Raymond J.

    2006-01-01

    Biology students in their first year at university have difficulty understanding the abstract concepts of photosynthesis. The traditional didactic lecture followed by practical exercises that show various macroscopic aspects of photosynthesis often do not help the students visualise or understand the submicroscopic (molecular-level) reactions that…

  10. Environmental and physiological control of dynamic photosynthesis

    NARCIS (Netherlands)

    Kaiser, M.E.

    2016-01-01

    Irradiance is the main driver of photosynthesis. In natural conditions, irradiance incident on a leaf often fluctuates, due to the movement of leaves, clouds and the sun. These fluctuations force photosynthesis to respond dynamically, however with delays that are subject to rate constants of underly

  11. CAD-CAM data exchange pilot project

    Energy Technology Data Exchange (ETDEWEB)

    Hintz, J.; Williams, D.

    1986-03-01

    CAD-CAM data were exchanged between dissimilar CAD systems and the information was used to fabricate three parts. Problems were identified and solutions were proposed or implemented in the area of translation methods, data verification, CAD drawing conventions, and data handling. Additional software needed for productive data exchange has been identified.

  12. Patients’ views of CAM as spiritual practice

    DEFF Research Database (Denmark)

    Ulrich, Anita; Evron, Lotte; Ostenfeld-Rosenthal, Ann

    2011-01-01

    CAM. Thirty-two cancer patients, family, friends and alternative practitioners were followed up over a two year period by face to face interview, telephone and focus groups. Results: Although religious and spiritual issues were not manifestly expressed by many of the subjects, these issues were...

  13. Some Workplace Effects of CAD and CAM.

    Science.gov (United States)

    Ebel, Karl-H.; Ulrich, Erhard

    1987-01-01

    Examines the impact of computer-aided design (CAD) and computer-aided manufacturing (CAM) on employment, work organization, working conditions, job content, training, and industrial relations in several countries. Finds little evidence of negative employment effects since productivity gains are offset by various compensatory factors. (Author/CH)

  14. The Path of Carbon in Photosynthesis VII. Respiration and Photosynthesis

    Science.gov (United States)

    Benson, A. A.; Calvin, M.

    1949-07-21

    The relationship of respiration to photosynthesis in barley seedling leaves and the algae, Chlorella and Scenedesmus, has been investigated using radioactive carbon dioxide and the techniques of paper chromatography and radioautography. The plants are allowed to photosynthesize normally for thirty seconds in c{sup 14}O{sub 2} after which they are allowed to respire in air or helium in the light or dark. Respiration of photosynthetic intermediates as evidenced by the appearance of labeled glutomic, isocitric, fumaric and succinic acids is slower in the light than in the dark. Labeled glycolic acid is observed in barley and algae. It disappears rapidly in the dark and is maintained and increased in quantity in the light in C0{sub 2}-free air.

  15. Complementary and alternative medicine use of women with breast cancer : Self-help CAM attracts other women than guided CAM therapies

    NARCIS (Netherlands)

    Lo-Fo-Wong, Deborah N. N.; Ranchor, Adelita V.; de Haes, Hanneke C. J. M.; Sprangers, Mirjam A. G.; Henselmans, Inge

    2012-01-01

    Objective: Examine stability of use of complementary and alternative medicine (CAM) of breast cancer patients, reasons for CAM use, and sociodemographic, clinical, and psychological predictors of CAM use. Methods: CAM use was assessed after adjuvant therapy and six months later. Following the CAM He

  16. From natural to artificial photosynthesis.

    Science.gov (United States)

    Barber, James; Tran, Phong D

    2013-04-01

    Demand for energy is projected to increase at least twofold by mid-century relative to the present global consumption because of predicted population and economic growth. This demand could be met, in principle, from fossil energy resources, particularly coal. However, the cumulative nature of carbon dioxide (CO(2)) emissions demands that stabilizing the atmospheric CO(2) levels to just twice their pre-anthropogenic values by mid-century will be extremely challenging, requiring invention, development and deployment of schemes for carbon-neutral energy production on a scale commensurate with, or larger than, the entire present-day energy supply from all sources combined. Among renewable and exploitable energy resources, nuclear fusion energy or solar energy are by far the largest. However, in both cases, technological breakthroughs are required with nuclear fusion being very difficult, if not impossible on the scale required. On the other hand, 1 h of sunlight falling on our planet is equivalent to all the energy consumed by humans in an entire year. If solar energy is to be a major primary energy source, then it must be stored and despatched on demand to the end user. An especially attractive approach is to store solar energy in the form of chemical bonds as occurs in natural photosynthesis. However, a technology is needed which has a year-round average conversion efficiency significantly higher than currently available by natural photosynthesis so as to reduce land-area requirements and to be independent of food production. Therefore, the scientific challenge is to construct an 'artificial leaf' able to efficiently capture and convert solar energy and then store it in the form of chemical bonds of a high-energy density fuel such as hydrogen while at the same time producing oxygen from water. Realistically, the efficiency target for such a technology must be 10 per cent or better. Here, we review the molecular details of the energy capturing reactions of natural

  17. A Comparative Study by δ13C-Analysis of Crassulacean Acid Metabolism (CAM) in Kalanchoë (Crassulaceae) Species of Africa and Madagascar

    International Nuclear Information System (INIS)

    The carbon isotope ratios (δ13C values) of samples of Kalanchoë species collected in Africa were compared with previous data obtained with species from Madagascar. In contrast to the Malagasy species which cover the whole range of δ13C values from −10 to − 30%o, indicating high inter- and intraspecific diversity of CAM performance, in the African species nearly all δ13C values were less negative than −18%0. Thus, in the African species the CAM behaviour is characterized by CO2 uptake proceeding mainly during the night. The distribution of δ13C values among the species clearly mirrors the taxonomic groups and the three sections of the genus Kalanchoë sensu lato. The Kitchingia section comprises only groups having CAM with a high proportion of carbon acquisition by the C3-pathway of photosynthesis. The same holds true for the first three groups of the Bryophyllum section, whereas in the following groups of the section CAM with CO2 proceeding mainly during the night is common. The latter CAM mode is typical also for the majority of groups and species in the section Eukalanchoë. The African Kalanchoë species belong to the Eukalanchoë section, whereas in Madagascar all three sections are abundant. The data support the view that the centre of adaptive radiation of the genus is located in Madagascar. They also suggest that high CAM variability is abundant in the more primitive taxa of the genus, whereas the phylogenetically more derived taxa show a stereotype CAM with CO2 uptake taking place only during the night. (author)

  18. Regulation of Calcium on Peanut Photosynthesis Under Low Night Temperature Stress

    Institute of Scientific and Technical Information of China (English)

    LIU Yi-fei; HAN Xiao-ri; ZHAN Xiu-mei; YANG Jin-feng; WANG Yu-zhi; SONG Qiao-bo; CHEN Xin

    2013-01-01

    The effects of different levels of CaCl2 on photosynthesis under low night temperature (8°C) stress in peanuts were studied in order to ifnd out the appropriate concentration of Ca2+ through the artiifcial climate chamber potted culture test. The results indicated that Ca2+, by means of improving the stomatal conductivity of peanut leaves under low night temperature stress, may mitigate the decline of photosynthetic rate in the peanut leaves. The regulation with 15 mmol L-1 CaCl2 (Ca15) was the most effective, compared with other treatments. Subsequently, the improvement of Ca2+ on peanut photosynthesis under low night temperature stress was validated further through spraying withCa15, Ca2+ chelator (ethylene glycol bis(2-aminoethyl) tetraacetic acid; EGTA) and calmodulin antagonists (trilfuonerazine; TFP).And CaM (Ca2+-modulin) played an important role in the nutritional signal transduction for Ca2+ mitigating photosynthesis limitations in peanuts under low night temperature stress.

  19. Stratospheric sulfate geoengineering could enhance the terrestrial photosynthesis rate

    Science.gov (United States)

    Xia, L.; Robock, A.; Tilmes, S.; Neely, R. R., III

    2016-02-01

    Stratospheric sulfate geoengineering could impact the terrestrial carbon cycle by enhancing the carbon sink. With an 8 Tg yr-1 injection of SO2 to produce a stratospheric aerosol cloud to balance anthropogenic radiative forcing from the Representative Concentration Pathway 6.0 (RCP6.0) scenario, we conducted climate model simulations with the Community Earth System Model - the Community Atmospheric Model 4 fully coupled to tropospheric and stratospheric chemistry (CAM4-chem). During the geoengineering period, as compared to RCP6.0, land-averaged downward visible (300-700 nm) diffuse radiation increased 3.2 W m-2 (11 %). The enhanced diffuse radiation combined with the cooling increased plant photosynthesis by 0.07 ± 0.02 µmol C m-2 s-1, which could contribute to an additional 3.8 ± 1.1 Gt C yr-1 global gross primary productivity without explicit nutrient limitation. This increase could potentially increase the land carbon sink. Suppressed plant and soil respiration due to the cooling would reduce natural land carbon emission and therefore further enhance the terrestrial carbon sink during the geoengineering period. This potentially beneficial impact of stratospheric sulfate geoengineering would need to be balanced by a large number of potential risks in any future decisions about the implementation of geoengineering.

  20. Photosynthesis and photorespiration in algae.

    Science.gov (United States)

    Lloyd, N D; Canvin, D T; Culver, D A

    1977-05-01

    The CO(2) exchange of several species of fresh water and marine algae was measured in the laboratory to determine whether photorespiration occurs in these organisms. The algae were positioned as thin layers on filter paper and the CO(2) exchange determined in an open gas exchange system. In either 21 or 1% O(2) there was little difference between (14)CO(2) and (12)CO(2) uptake. Apparent photosynthesis was the same in 2, 21, or 50% O(2). The compensation points of all algae were less than 10 mul 1(-1). CO(2) or (14)CO(2) evolution into CO(2)-free air in the light was always less than the corresponding evolution in darkness. These observations are inconsistent with the proposal that photorespiration exists in these algae. PMID:16659972

  1. Model systems in photosynthesis research

    International Nuclear Information System (INIS)

    After a general discussion of model studies in photosynthesis research, three recently developed model systems are described. The current status of covalently linked chlorophyll pairs as models for P700 and P865 is first briefly reviewed. Mg-tris(pyrochlorophyllide)1,1,1-tris(hydroxymethyl) ethane triester in its folded configuration is then discussed as a rudimentary antenna-photoreaction center model. Finally, self-assembled chlorophyll systems that contain a mixture of monomeric, oligomeric and special pair chlorophyll are shown to have fluorescence emission characteristics that resemble thoe of intact Tribonema aequale at room temperature in that both show fluorescence emission at 675 and 695 nm. In the self-assembled systems the wavelength of the emitted fluorescence depends on the wavelength of excitation, arguing that energy transfer between different chlorophyll species in these systems may be more complex than previously suspected

  2. The oldest records of photosynthesis

    Science.gov (United States)

    Awramik, S. M.

    1992-01-01

    There is diverse, yet controversial fossil evidence for the existence of photosynthesis 3500 million years ago. Among the most persuasive evidence is the stromatolites described from low grade metasedimentary rocks in Western Australia and South Africa. Based on the understanding of the paleobiology of stromatolites and using pertinent fossil and Recent analogs, these Early Archean stromatolites suggest that phototrophs evolved by 3500 million years ago. The evidence allows further interpretation that cyanobacteria were involved. Besides stromatolites, microbial and chemical fossils are also known from the same rock units. Some microfossils morphologically resemble cyanobacteria and thus complement the adduced cyanobacterial involvement in stromatolite construction. If cyanobacteria had evolved by 3500 million years ago, this would indicate that nearly all prokaryotic phyla had already evolved and that prokaryotes diversified rapidly on the early Earth.

  3. INTERACTIVE ILUSTRATION FOR PHOTOSYNTHESIS TEACHING

    Directory of Open Access Journals (Sweden)

    M.R. Pereira

    2004-05-01

    Full Text Available Computational resources became the major tool in the challenge of making high education moreeasy and motivating. Complex Biochemical pathways can now be presented in interactive and three-dimensional animations. One of the most complex (detailed and interesting metabolic pathway thatstudents must understand in biochemical courses is photosynthesis. The light-dependent reactionsare of special interest since they involve many dierent kinds of mechanisms, as light absorptionby membrane complexes, proteins movement inside membranes, reactions of water hydrolysis, andelectrons ow; making it dicult to understand by static bi-dimensional representations.The resources of animation and ActionScript programming were used to make an interactive ani-mation of photosynthesis, which at some times even simulates three-dimensionality. The animationbegins with a leaf and progressively zooms in, until we have a scheme of a tylakoyd membrane, whereeach of the dierent steps of the pathway can be clicked to reveal a more detailed scheme of it. Whereappropriate, the energy graphs are shown side by side with the reactions. The electron is representedwith a face, so it can be shown to be stressing while going up in the energy graphs. Finally, there isa simplied version of the whole pathway, to illustrate how it all goes together.The objective is to help professors on teaching the subject in regular classes, since currently allthe explanations are omitted. In a future version, texts will be added to each step so it can beself-explicative to the students, helping them even on home or on-line learning.

  4. Introduction to Analytical Methods for Internal Combustion Engine Cam Mechanisms

    CERN Document Server

    Williams, J J

    2013-01-01

    Modern design methods of Automotive Cam Design require the computation of a range of parameters. This book provides a logical sequence of steps for the derivation of the relevant equations from first principles, for the more widely used cam mechanisms. Although originally derived for use in high performance engines, this work is equally applicable to the design of mass produced automotive and other internal combustion engines.   Introduction to Analytical Methods for Internal Combustion Engine Cam Mechanisms provides the equations necessary for the design of cam lift curves with an associated smooth acceleration curve. The equations are derived for the kinematics and kinetics of all the mechanisms considered, together with those for cam curvature and oil entrainment velocity. This permits the cam shape, all loads, and contact stresses to be evaluated, and the relevant tribology to be assessed. The effects of asymmetry on the manufacture of cams for finger follower and offset translating curved followers is ...

  5. The detection of EpCAM+ and EpCAM- circulating tumor cells

    OpenAIRE

    Wit, de, J.; Dalum, van, G.; Lenferink, Aufried T. M.; Arjan G. J. Tibbe; Hiltermann, T.J.N.; Groen, Harry J. M.; Rijn, van, Michela; Terstappen, Leon W.M.M.

    2015-01-01

    EpCAM expressing circulating tumor cells, detected by CellSearch, are predictive of short survival in several cancers and may serve as a liquid biopsy to guide therapy. Here we investigate the presence of EpCAM+ CTC detected by CellSearch and EpCAM- CTC discarded by CellSearch, after EpCAM based enrichment. EpCAM- CTC were identified by filtration and fluorescent labelling. This approach was validated using different cell lines spiked into blood and evaluated on blood samples of 27 metastatic...

  6. Photosynthesis in Hydrogen-Dominated Atmospheres

    Directory of Open Access Journals (Sweden)

    William Bains

    2014-11-01

    Full Text Available The diversity of extrasolar planets discovered in the last decade shows that we should not be constrained to look for life in environments similar to early or present-day Earth. Super-Earth exoplanets are being discovered with increasing frequency, and some will be able to retain a stable, hydrogen-dominated atmosphere. We explore the possibilities for photosynthesis on a rocky planet with a thin H2-dominated atmosphere. If a rocky, H2-dominated planet harbors life, then that life is likely to convert atmospheric carbon into methane. Outgassing may also build an atmosphere in which methane is the principal carbon species. We describe the possible chemical routes for photosynthesis starting from methane and show that less energy and lower energy photons could drive CH4-based photosynthesis as compared with CO2-based photosynthesis. We find that a by-product biosignature gas is likely to be H2, which is not distinct from the hydrogen already present in the environment. Ammonia is a potential biosignature gas of hydrogenic photosynthesis that is unlikely to be generated abiologically. We suggest that the evolution of methane-based photosynthesis is at least as likely as the evolution of anoxygenic photosynthesis on Earth and may support the evolution of complex life.

  7. Formal Management of CAD/CAM Processes

    Science.gov (United States)

    Kohlhase, Michael; Lemburg, Johannes; Schröder, Lutz; Schulz, Ewaryst

    Systematic engineering design processes have many aspects in common with software engineering, with CAD/CAM objects replacing program code as the implementation stage of the development. They are, however, currently considerably less formal. We propose to draw on the mentioned similarities and transfer methods from software engineering to engineering design in order to enhance in particular the reliability and reusability of engineering processes. We lay out a vision of a document-oriented design process that integrates CAD/CAM documents with requirement specifications; as a first step towards supporting such a process, we present a tool that interfaces a CAD system with program verification workflows, thus allowing for completely formalised development strands within a semi-formal methodology.

  8. CAD/CAM-assisted breast reconstruction

    International Nuclear Information System (INIS)

    The application of computer-aided design and manufacturing (CAD/CAM) techniques in the clinic is growing slowly but steadily. The ability to build patient-specific models based on medical imaging data offers major potential. In this work we report on the feasibility of employing laser scanning with CAD/CAM techniques to aid in breast reconstruction. A patient was imaged with laser scanning, an economical and facile method for creating an accurate digital representation of the breasts and surrounding tissues. The obtained model was used to fabricate a customized mould that was employed as an intra-operative aid for the surgeon performing autologous tissue reconstruction of the breast removed due to cancer. Furthermore, a solid breast model was derived from the imaged data and digitally processed for the fabrication of customized scaffolds for breast tissue engineering. To this end, a novel generic algorithm for creating porosity within a solid model was developed, using a finite element model as intermediate.

  9. CAD/CAM-assisted breast reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Melchels, Ferry; Hutmacher, Dietmar Werner [Institute of Health and Biomedical Innovation, Queensland University of Technology, 60 Musk Avenue, Kelvin Grove, QLD 4059 (Australia); Wiggenhauser, Paul Severin; Schantz, Jan-Thorsten [Department of Plastic and Hand Surgery, Klinikum rechts der Isar, Technische Universitaet Muenchen, Ismaninger Strasse 22, 81675 Munich (Germany); Warne, David; Barry, Mark [High Performance Computing and Research Support, Queensland University of Technology, Gardens Point Road, Brisbane, QLD 4000 (Australia); Ong, Fook Rhu; Chong, Woon Shin, E-mail: Dietmar.Hutmacher@qut.edu.au, E-mail: jtschantz@lrz.tu-muenchen.de [Singapore Polytechnic, 500 Dover Road, 139651 Singapore (Singapore)

    2011-09-15

    The application of computer-aided design and manufacturing (CAD/CAM) techniques in the clinic is growing slowly but steadily. The ability to build patient-specific models based on medical imaging data offers major potential. In this work we report on the feasibility of employing laser scanning with CAD/CAM techniques to aid in breast reconstruction. A patient was imaged with laser scanning, an economical and facile method for creating an accurate digital representation of the breasts and surrounding tissues. The obtained model was used to fabricate a customized mould that was employed as an intra-operative aid for the surgeon performing autologous tissue reconstruction of the breast removed due to cancer. Furthermore, a solid breast model was derived from the imaged data and digitally processed for the fabrication of customized scaffolds for breast tissue engineering. To this end, a novel generic algorithm for creating porosity within a solid model was developed, using a finite element model as intermediate.

  10. CAD/CAM at Gullick Dobson Ltd

    Energy Technology Data Exchange (ETDEWEB)

    1985-11-01

    Gullick Dobson introduced computer-aided design systems more than four years ago, and those have improved the standard of technical presentation for tendering as well as saving time and the repetitive mundane work involved in incorporating standard plants onto several drawings. Computer-aided manufacture has also helped to reduce costs and in future interactive CAD/CAM will be developed where total engineering will result in the best product.

  11. CAD/CAM: influencing the skilled trades

    Energy Technology Data Exchange (ETDEWEB)

    Plomp, P.W.

    1983-01-01

    CAD/CAM is influencing many of the skilled trades. Computers are permitting an increase in productivity with a resulting need for people with greater mental rather than motor skills. Computers are used for the control of a wide variety of manufacturing operations and the trend is accelerating rapidly. The net result is a smaller need for semi-skilled jobs but an increasing demand for skilled craftsmen.

  12. Deterministic mathematical morphology for CAD/CAM

    OpenAIRE

    Sarabia Pérez, Rubén; Jimeno Morenilla, Antonio; Molina Carmona, Rafael

    2014-01-01

    Purpose – The purpose of this paper is to present a new geometric model based on the mathematical morphology paradigm, specialized to provide determinism to the classic morphological operations. The determinism is needed to model dynamic processes that require an order of application, as is the case for designing and manufacturing objects in CAD/CAM environments. Design/methodology/approach – The basic trajectory-based operation is the basis of the proposed morphological specialization. This ...

  13. The NectarCAM camera project

    CERN Document Server

    Glicenstein, J-F; Barrio, J-A; Blanch, O; Boix, J; Bolmont, J; Boutonnet, C; Cazaux, S; Chabanne, E; Champion, C; Chateau, F; Colonges, S; Corona, P; Couturier, S; Courty, B; Delagnes, E; Delgado, C; Ernenwein, J-P; Fegan, S; Ferreira, O; Fesquet, M; Fontaine, G; Fouque, N; Henault, F; Gascón, D; Herranz, D; Hermel, R; Hoffmann, D; Houles, J; Karkar, S; Khelifi, B; Knödlseder, J; Martinez, G; Lacombe, K; Lamanna, G; LeFlour, T; Lopez-Coto, R; Louis, F; Mathieu, A; Moulin, E; Nayman, P; Nunio, F; Olive, J-F; Panazol, J-L; Petrucci, P-O; Punch, M; Prast, J; Ramon, P; Riallot, M; Ribó, M; Rosier-Lees, S; Sanuy, A; Siero, J; Tavernet, J-P; Tejedor, L A; Toussenel, F; Vasileiadis, G; Voisin, V; Waegebert, V; Zurbach, C

    2013-01-01

    In the framework of the next generation of Cherenkov telescopes, the Cherenkov Telescope Array (CTA), NectarCAM is a camera designed for the medium size telescopes covering the central energy range of 100 GeV to 30 TeV. NectarCAM will be finely pixelated (~ 1800 pixels for a 8 degree field of view, FoV) in order to image atmospheric Cherenkov showers by measuring the charge deposited within a few nanoseconds time-window. It will have additional features like the capacity to record the full waveform with GHz sampling for every pixel and to measure event times with nanosecond accuracy. An array of a few tens of medium size telescopes, equipped with NectarCAMs, will achieve up to a factor of ten improvement in sensitivity over existing instruments in the energy range of 100 GeV to 10 TeV. The camera is made of roughly 250 independent read-out modules, each composed of seven photo-multipliers, with their associated high voltage base and control, a read-out board and a multi-service backplane board. The read-out b...

  14. The relationship of CO2 assimilation pathways and photorespiration to the physiological quantum requirement of green plant photosynthesis.

    Science.gov (United States)

    Campbell, W H; Black, C C

    1978-08-01

    The quantum requirement of green cells for CO2 fixation has been evaluated and discussed in view of the recent discovery of photorespiration and of multiple biochemical pathways for photosynthetic CO2 fixation. The reported quantum requirement of algae generally is near 9 quanta per CO2 fixed. It is suggested that the high CO2 concentrations and low O2 concentrations used for these algae experiments would have completely suppressed photorespiration and, therefore, the minimum number of quanta required to fix 1 CO2 molecule was correctly determined in these experiments. With higher plant leaves, when measurements are made under physiological environments, quantum requirements range from about 12 to 20 quanta per CO2 fixed. It is suggested that these physiological quantum requirements are higher because photorespiration is functional in these leaves and that photorespiration requires energy. The energy requirement of photorespiration was derived using biochemical models of leaf photosynthesis combining photorespiration with specific biochemical pathways for CO2 fixation. The calculated physiological quantum requirements for C3, C4 and CAM plant photosynthesis are 13, 15 and 17 respectively. The literature values on quantum requirements correspond well with these biochemical models of net photosynthesis. However, it was concluded that the biochemical models fail to give a complete description of photosynthesis in plants using the C4-dicarboxylic acid cycle. PMID:719139

  15. Development of optimal cam contours; Entwicklung von optimalen Nockenkonturen

    Energy Technology Data Exchange (ETDEWEB)

    Grosse-Loescher, Hendrik; Haberland, Heiner [MAN-Diesel SE, Augsburg (Germany)

    2011-07-01

    A closed-loop method for the development of an optimal shape of an injection cam for a common rail injection system of a large-bore Diesel engine is presented. Due to the demanded fuel flow rate of the engine, a three-loop cam is necessary. The optimal shape of the cam results of a multitude of criteria, constaints and optimization aims. A stepwise resolution of 0.5 rotation angle of the cam shape is required due to manufacturing demands. One single cam shape consists of 120 rotation angles. Thus, the calculation of the optimal cam shape comprises 241 nodes. The method described aims to develop an optimal cam shape depending on all criteria and constaints. Due to the huge number of constraints as well as the complex calculations, the application of a particle swarm optimization (PSA) algorithm is proposed. An optimal cam shape complies to all demands required at each single node. Therefore, a loose lifting curve without any additional conditions applying, such as e.g. linear velocity profiles, is created. Following this procedure, all potentials are best exploited. Each node of the cam shape is basically independent of all other nodes within the chosen demands and constaints. The nodes are thus treated as independent parameters. The procedure described generates optimal cam shapes. (orig.)

  16. Photosynthesis and Respiration in Leaf Slices.

    Science.gov (United States)

    Brown, Simon

    1998-01-01

    Demonstrates how leaf slices provide an inexpensive material for illustrating several fundamental points about the biochemistry of photosynthesis and respiration. Presents experiments that illustrate the effects of photon flux density and herbicides and carbon dioxide concentration. (DDR)

  17. Final report, Feedback limitations of photosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Sharkey, Thomas D.

    1999-07-22

    Final report of research on carbon metabolism of photosynthesis. The feedback from carbon metabolism to primary photosynthetic processes is summarized, and a comprehensive list of published scientific papers is provided.

  18. Chem 1 Supplement: Energy Interconversions in Photosynthesis.

    Science.gov (United States)

    Bering, Charles L.

    1985-01-01

    Examines energy interconversions in photosynthesis, limiting the discussion to areas pertinent to chemistry (particularly the energetics of the light reactions). Topic areas considered include bioenergetics, photochemistry, conversion of light energy into electrical potential energy, the chemiosmotic hypothesis, and others. (JN)

  19. Using photosynthesis to detect plant stress

    Science.gov (United States)

    1994-01-01

    Two Stennis Space Center scientists use a photosynthesis measuring system on a pine tree at the Harrison County Experimental Forest about 15 miles north of Gulfport, Miss. The scientists have discovered a new method of detecting plant stress.

  20. Photosynthesis in Antarctic sea ice diatoms

    OpenAIRE

    Mock, Thomas

    2003-01-01

    This thesis was conducted to apply new techniques for measuring photosynthesis in Antarctic sea ice diatoms. A systematic approach of investigations was applied to obtain precise measurements of photosynthesis under natural conditions in the field from which questions were derived for further analysis in the laboratory. In situ measurements with the tracer 14C through the entire thickness of a young sea ice floe revealed that algae are able to actively assimilate dissolved inorganic carbon un...

  1. Development of the pipe machining CAD/CAM system; Kankako CAD/CAM system no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Taketomi, Y.; Teshima, H.; Suzuki, T.; Yoshida, A.

    1997-11-05

    The pipe machining CAD/CAM system was developed which can use previously prepared CAD input data for piping work diagrams. This system can automatically prepare diagrams and information necessary for machining, packaging, handling/lifting planning and assembly of pipes from previously inputted data. Output contents are as follows: parts machining diagram, piping work diagram, piping parts table, label, parts packaging/loading indication, transport program, assembly diagram (isometric diagram, plan). Since all data are transmitted to CAM system in automatic machining, these outputs are unnecessary. A reliable pipe machining system (automatic screwing/cutting machine) was prepared by improving recognized existing machines. The new mechanism (pipe automatic warehouse) which can certainly take out a desired pipe from randomly stacked pipes by an originally developed `rotation disk.` A precise measurement equipment was also developed by using a stopper arm and encoder. The CAD/CAM system achieved labor saving requiring only 1-2 operators. 3 figs.

  2. Parametric Modeling for Globoidal Cam Based and NC Machining

    Directory of Open Access Journals (Sweden)

    Haitao Liu

    2013-02-01

    Full Text Available The design and machining of globoidal cam is difficult, because the shape of working surface is complex,and the curved surface of its space is undevelopable. Based on the above reasons,we proposed the parametric Modeling method for globoidal cam based. Through the secondary development, we realized the parameterized modeling of globoidal cam. Base on using of globular indexing cam NC milling machine existing in the lab,research the programming technology,analyses the defects of conventional programming method,raise improvement measures,control the programming error,modify the feeding speed,develop the special purpose programming software, creat globular indexing cam NC machining program automaticly ,improve the machining precision and efficiency of globular indexing cam.  

  3. Availability Analysis of the Ventilation Stack CAM Interlock System

    International Nuclear Information System (INIS)

    Ventilation Stack Continuous Air Monitor (CAM) Interlock System failure modes, failure frequencies and system availability have been evaluated for the RPP. The evaluation concludes that CAM availability is as high as assumed in the safety analysis and that the current routine system surveillance is adequate to maintain this availability. Further, requiring an alarm to actuate upon CAM failure is not necessary to maintain the availability credited in the safety analysis, nor is such an arrangement predicted to significantly improve system availability. However, if CAM failures were only detected by the 92-day functional tests required in the Authorization Basis (AB), CAM availability would be much less than that credited in the safety analysis. Therefore it is recommended that the current surveillance practice of daily simple system checks, 30-day source checks and 92-day functional tests be continued in order to maintain CAM availability

  4. Resin-composite Blocks for Dental CAD/CAM Applications

    OpenAIRE

    Ruse, N.D.; Sadoun, M.J.

    2014-01-01

    Advances in digital impression technology and manufacturing processes have led to a dramatic paradigm shift in dentistry and to the widespread use of computer-aided design/computer-aided manufacturing (CAD/CAM) in the fabrication of indirect dental restorations. Research and development in materials suitable for CAD/CAM applications are currently the most active field in dental materials. Two classes of materials are used in the production of CAD/CAM restorations: glass-ceramics/ceramics and ...

  5. Treatment Preferences for CAM in Children with Chronic Pain

    OpenAIRE

    Tsao, Jennie C. I.; Marcia Meldrum; Kim, Su C.; Jacob, Margaret C.; Zeltzer, Lonnie K

    2006-01-01

    CAM therapies have become increasingly popular in pediatric populations. Yet, little is known about children's preferences for CAM. This study examined treatment preferences in chronic pediatric pain patients offered a choice of CAM therapies for their pain. Participants were 129 children (94 girls) (mean age = 14.5 years ± 2.4; range = 8–18 years) presenting at a multidisciplinary, tertiary clinic specializing in pediatric chronic pain. Bivariate and multivariate analyses were used to examin...

  6. Compression Testing Using a CAM-Driven Electromagnetic Machine

    OpenAIRE

    Martins, Paulo; Rosa, Pedro; Silva, Carlos

    2012-01-01

    This paper presents new equipment for the compression testing of materials under high rates of loading. The equipment consists of an electromagnetic actuator, a fixed housing containing two flat compression platens, a translating cam and a follower. The electromagnetic actuator makes possible reaching high strain rates with a very precise control of the impact velocity and of the energy transmitted to the translating cam. The cam profile enables compression testing to be perfor...

  7. New Conception of Waving Machine CamEl Drive

    Science.gov (United States)

    Bílkovský, A.; Marek, O.; Jirásko, P.; Volanský, Z.

    New mechatronic conception of waving machine CamEl drive is realized by two electronic cams Yaskawa and planetary gears. The first servo motor is used to slay and shedding motion in position mode and the second servo motor is used in automatic weaving mode. Moment of inertia of kinematic chain was reduced that it was possible used a smaller servo motor of electronic cam Yaskawa.

  8. CAD/CAM of braided preforms for advanced composites

    Science.gov (United States)

    Yang, Gui; Pastore, Christopher; Tsai, Yung Jia; Soebroto, Heru; Ko, Frank

    A CAD/CAM system for braiding to produce preforms for advanced textile structural composites is presented in this paper. The CAD and CAM systems are illustrated in detail. The CAD system identifies the fiber placement and orientation needed to fabricate a braided structure over a mandrel, for subsequent composite formation. The CAM system uses the design parameters generated by the CAD system to control the braiding machine. Experimental evidence demonstrating the success of combining these two technologies to form a unified CAD/CAM system for the manufacture of braided fabric preforms with complex structural shapes is presented.

  9. Estimating phytoplankton photosynthesis by active fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Falkowski, P.G.; Kolber, Z.

    1992-10-01

    Photosynthesis can be described by target theory, At low photon flux densities, photosynthesis is a linear function of irradiance (I), The number of reaction centers (n), their effective absorption capture cross section {sigma}, and a quantum yield {phi}. As photosynthesis becomes increasingly light saturated, an increased fraction of reaction centers close. At light saturation the maximum photosynthetic rate is given as the product of the number of reaction centers (n) and their maximum electron transport rate (I/{tau}). Using active fluorometry it is possible to measure non-destructively and in real time the fraction of open or closed reaction centers under ambient irradiance conditions in situ, as well as {sigma} and {phi} {tau} can be readily, calculated from knowledge of the light saturation parameter, I{sub k} (which can be deduced by in situ by active fluorescence measurements) and {sigma}. We built a pump and probe fluorometer, which is interfaced with a CTD. The instrument measures the fluorescence yield of a weak probe flash preceding (f{sub 0}) and succeeding (f{sub 0}) a saturating pump flash. Profiles of the these fluorescence yields are used to derive the instantaneous rate of gross photosynthesis in natural phytoplankton communities without any incubation. Correlations with short-term simulated in situ radiocarbon measurements are extremely high. The average slope between photosynthesis derived from fluorescence and that measured by radiocarbon is 1.15 and corresponds to the average photosynthetic quotient. The intercept is about 15% of the maximum radiocarbon uptake and corresponds to the average net community respiration. Profiles of photosynthesis and sections showing the variability in its composite parameters reveal a significant effect of nutrient availability on biomass specific rates of photosynthesis in the ocean.

  10. The many meanings of gross photosynthesis and their implication for photosynthesis research from leaf to globe

    Science.gov (United States)

    Gu, Lianghong; Wohlfahrt, Georg

    2015-04-01

    Gross photosynthesis is a key term and concept in carbon cycle science. It however turns out that this term has been and is used with different meanings by different communities - either with (historically referred to as apparent photosynthesis) or without (historically referred to as true photosynthesis) including photorespiration - which has been and still is causing confusion. Here we review the history of these terms and the underlying theory to clarify the terminology and make recommendations about a consistent use of terms. We further show that eddy covariance CO2 flux partitioning, due to an overestimation of daytime mitochondrial respiration and our inability to estimate photorespiration, yields estimates which are quantitatively closer to the definition of true photosynthesis (i.e. carboxylation only) despite aiming at estimating apparent photosynthesis (i.e. carboxylation minus photorespiration). The implications of this finding are discussed.

  11. Konepajan siirtyminen CAD-CAM-ohjelmointiin

    OpenAIRE

    Moisanen, Sari

    2011-01-01

    Sandvik Mining and Construction Köping AB Haparanda aloitti konepajauudistusprojektin kesällä 2008. Uudistuksen tavoitteena oli kasvattaa konepajan tuotantokapasiteettia ja muuttaa tuotantotapa funktionaalisesta solumuotoiseksi. Uudistuksen myötä konepajalle hankittiin keväällä 2009 kolme uutta NC-sorvia ja tietokoneavusteiseen ohjelmointiin soveltuva WinCAM-ohjelmisto. Osa konepajan tuotantohenkilöstöstä koulutettiin käyttämään NC-ohjelmointia ja tekemään NC-ohjelmia Fanucin käyttöjärjestelm...

  12. Compartilhando protocolos: maquina CMM / CAD / CAM

    OpenAIRE

    Pinheiro Beck, Joao Carlos; Lima da Silva, Isaac Newton; Baroni, Alexandre; Mazin Dias, Gilver

    2007-01-01

    A meta desta contribuição é a descrição da metodologia utilizada para compartilhar um software comercial de CAD/CAM, orientado à indústria mecânica, com um equipamento industrial de controle de qualidade tridimensional (CMM). As etapas necessárias a esta integração são apresentadas, passo a passo, para facilitar o entendimento e a visualização progressiva de cada uma das fases de estudo e análise. Tomando-se como referência este compartilhamento, efetuouse, como aplicação do proce...

  13. CAD/CAM-assisted breast reconstruction.

    Science.gov (United States)

    Melchels, Ferry; Wiggenhauser, Paul Severin; Warne, David; Barry, Mark; Ong, Fook Rhu; Chong, Woon Shin; Hutmacher, Dietmar Werner; Schantz, Jan-Thorsten

    2011-09-01

    The application of computer-aided design and manufacturing (CAD/CAM) techniques in the clinic is growing slowly but steadily. The ability to build patient-specific models based on medical imaging data offers major potential. In this work we report on the feasibility of employing laser scanning with CAD/CAM techniques to aid in breast reconstruction. A patient was imaged with laser scanning, an economical and facile method for creating an accurate digital representation of the breasts and surrounding tissues. The obtained model was used to fabricate a customized mould that was employed as an intra-operative aid for the surgeon performing autologous tissue reconstruction of the breast removed due to cancer. Furthermore, a solid breast model was derived from the imaged data and digitally processed for the fabrication of customized scaffolds for breast tissue engineering. To this end, a novel generic algorithm for creating porosity within a solid model was developed, using a finite element model as intermediate. PMID:21900731

  14. CAMS confirmation of previously reported meteor showers

    Science.gov (United States)

    Jenniskens, P.; Nénon, Q.; Gural, P. S.; Albers, J.; Haberman, B.; Johnson, B.; Holman, D.; Morales, R.; Grigsby, B. J.; Samuels, D.; Johannink, C.

    2016-03-01

    Leading up to the 2015 IAU General Assembly, the International Astronomical Union's Working List of Meteor Showers included 486 unconfirmed showers, showers that are not certain to exist. If confirmed, each shower would provide a record of past comet or asteroid activity. Now, we report that 41 of these are detected in the Cameras for Allsky Meteor Surveillance (CAMS) video-based meteor shower survey. They manifest as meteoroids arriving at Earth from a similar direction and orbit, after removing the daily radiant drift due to Earth's motion around the Sun. These showers do exist and, therefore, can be moved to the IAU List of Established Meteor Showers. This adds to 31 previously confirmed showers from CAMS data. For each shower, finding charts are presented based on 230,000 meteors observed up to March of 2015, calculated by re-projecting the drift-corrected Sun-centered ecliptic coordinates into more familiar equatorial coordinates. Showers that are not detected, but should have, and duplicate showers that project to the same Sun-centered ecliptic coordinates, are recommended for removal from the Working List.

  15. CAD/CAM: Practical and Persuasive in Canadian Schools

    Science.gov (United States)

    Willms, Ed

    2007-01-01

    Chances are that many high school students would not know how to use drafting instruments, but some might want to gain competence in computer-assisted design (CAD) and possibly computer-assisted manufacturing (CAM). These students are often attracted to tech courses by the availability of CAD/CAM instructions, and many go on to impress employers…

  16. Application of CAM in online measurement of mechanical parameters

    OpenAIRE

    Xiaokang, Gao

    2013-01-01

    Online Measurement of mechanical parameters by using CAM (Computer Aided Measurement) is a new advanced technique in the field of measurement. Taking special measurement software DASYLab as an example, this paper describes the basic principles and unique advantages of this technique. The application of CAM is explained through an example of measurements of temperature, flow rate and pressure.

  17. Radiation and photosynthesis in kiwifruit canopies

    International Nuclear Information System (INIS)

    Inclination angles, incident radiation, and photosynthesis were measured for leaves of kiwifruit vines in the field. Soon after flowering, mean leaf inclination angles were 29.5° and 27.6° for vines on T-bar and pergola trellises respectively. The diurnal integral of incident radiation for the upward-facing part of a T-bar vine exceeded that for the inclined part, by 50–100%. The radiation saturated rate of photosynthesis increased from 8–10 μmol CO2 m-2 s-1 about 1 month after leaf emergence to about 16–17 μmol CO2 m-2 s-1 at 3–5 months after leaf emergence, before declining as leaves senesced in autumn. The quantum efficiency increased marginally with leaf age. Simulated canopy photosynthesis early in the season was strongly related to leaf area development. (author)

  18. Anoxygenic Photosynthesis Controls Oxygenic Photosynthesis in a Cyanobacterium from a Sulfidic Spring

    KAUST Repository

    Klatt, Judith M.

    2015-03-15

    Before the Earth\\'s complete oxygenation (0.58 to 0.55 billion years [Ga] ago), the photic zone of the Proterozoic oceans was probably redox stratified, with a slightly aerobic, nutrient-limited upper layer above a light-limited layer that tended toward euxinia. In such oceans, cyanobacteria capable of both oxygenic and sulfide-driven anoxygenic photosynthesis played a fundamental role in the global carbon, oxygen, and sulfur cycle. We have isolated a cyanobacterium, Pseudanabaena strain FS39, in which this versatility is still conserved, and we show that the transition between the two photosynthetic modes follows a surprisingly simple kinetic regulation controlled by this organism\\'s affinity for H2S. Specifically, oxygenic photosynthesis is performed in addition to anoxygenic photosynthesis only when H2S becomes limiting and its concentration decreases below a threshold that increases predictably with the available ambient light. The carbon-based growth rates during oxygenic and anoxygenic photosynthesis were similar. However, Pseudanabaena FS39 additionally assimilated NO3 - during anoxygenic photosynthesis. Thus, the transition between anoxygenic and oxygenic photosynthesis was accompanied by a shift of the C/N ratio of the total bulk biomass. These mechanisms offer new insights into the way in which, despite nutrient limitation in the oxic photic zone in the mid-Proterozoic oceans, versatile cyanobacteria might have promoted oxygenic photosynthesis and total primary productivity, a key step that enabled the complete oxygenation of our planet and the subsequent diversification of life.

  19. Global analysis of photosynthesis transcriptional regulatory networks.

    Science.gov (United States)

    Imam, Saheed; Noguera, Daniel R; Donohue, Timothy J

    2014-12-01

    Photosynthesis is a crucial biological process that depends on the interplay of many components. This work analyzed the gene targets for 4 transcription factors: FnrL, PrrA, CrpK and MppG (RSP_2888), which are known or predicted to control photosynthesis in Rhodobacter sphaeroides. Chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-seq) identified 52 operons under direct control of FnrL, illustrating its regulatory role in photosynthesis, iron homeostasis, nitrogen metabolism and regulation of sRNA synthesis. Using global gene expression analysis combined with ChIP-seq, we mapped the regulons of PrrA, CrpK and MppG. PrrA regulates ∼34 operons encoding mainly photosynthesis and electron transport functions, while CrpK, a previously uncharacterized Crp-family protein, regulates genes involved in photosynthesis and maintenance of iron homeostasis. Furthermore, CrpK and FnrL share similar DNA binding determinants, possibly explaining our observation of the ability of CrpK to partially compensate for the growth defects of a ΔFnrL mutant. We show that the Rrf2 family protein, MppG, plays an important role in photopigment biosynthesis, as part of an incoherent feed-forward loop with PrrA. Our results reveal a previously unrealized, high degree of combinatorial regulation of photosynthetic genes and significant cross-talk between their transcriptional regulators, while illustrating previously unidentified links between photosynthesis and the maintenance of iron homeostasis. PMID:25503406

  20. Global analysis of photosynthesis transcriptional regulatory networks.

    Directory of Open Access Journals (Sweden)

    Saheed Imam

    2014-12-01

    Full Text Available Photosynthesis is a crucial biological process that depends on the interplay of many components. This work analyzed the gene targets for 4 transcription factors: FnrL, PrrA, CrpK and MppG (RSP_2888, which are known or predicted to control photosynthesis in Rhodobacter sphaeroides. Chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-seq identified 52 operons under direct control of FnrL, illustrating its regulatory role in photosynthesis, iron homeostasis, nitrogen metabolism and regulation of sRNA synthesis. Using global gene expression analysis combined with ChIP-seq, we mapped the regulons of PrrA, CrpK and MppG. PrrA regulates ∼34 operons encoding mainly photosynthesis and electron transport functions, while CrpK, a previously uncharacterized Crp-family protein, regulates genes involved in photosynthesis and maintenance of iron homeostasis. Furthermore, CrpK and FnrL share similar DNA binding determinants, possibly explaining our observation of the ability of CrpK to partially compensate for the growth defects of a ΔFnrL mutant. We show that the Rrf2 family protein, MppG, plays an important role in photopigment biosynthesis, as part of an incoherent feed-forward loop with PrrA. Our results reveal a previously unrealized, high degree of combinatorial regulation of photosynthetic genes and significant cross-talk between their transcriptional regulators, while illustrating previously unidentified links between photosynthesis and the maintenance of iron homeostasis.

  1. Cam Drive Step Mechanism of a Quadruped Robot

    Directory of Open Access Journals (Sweden)

    Qun Sun

    2014-01-01

    Full Text Available Bionic quadruped robots received considerable worldwide research attention. For a quadruped robot walking with steady paces on a flat terrain, using a cam drive control mechanism instead of servomotors provides theoretical and practical benefits as it reduces the system weight, cost, and control complexities; thus it may be more cost beneficial for some recreational or household applications. This study explores the robot step mechanism including the leg and cam drive control systems based on studying the bone structure and the kinematic step sequences of dog. The design requirements for the cam drive robot legs have been raised, and the mechanical principles of the leg operating mechanism as well as the control parameters have been analyzed. A cam drive control system was constructed using three cams to control each leg. Finally, a four-leg demo robot was manufactured for experiments and it showed stable walking patterns on a flat floor.

  2. Knowledge and training needs among Danish nurses about CAM

    DEFF Research Database (Denmark)

    Lunde, Anita

    2010-01-01

    Background: The increased use of CAM among the Danish population is well documented as are patient’s requests to discuss CAM with a healthcare professional. It is suggested that among different groups of healthcare professionals nurses are the most “open minded” about CAM. This makes it important...... to explore nurses’ knowledge about CAM and their needs for training. Methods: Similar to international investigations a Danish “CAM-knowledge” questionnaire was developed that included multiple choice, yes/no and 5 points scale answers. Validity was established through initial pilot testing. Contacts...... to a randomized sample of 2500 nurses were established through the Danish Nurses Foundation. The questionnaires were mailed by post with the possibility of anonymous return. The data material was analyzed using non-parametic methods. Results: The response rate was 67 % and 1458 completed...

  3. Photosynthesis and the world food problem

    Directory of Open Access Journals (Sweden)

    Jerzy Poskuta

    2014-02-01

    Full Text Available Studies in the field of photosynthesis are particularly predisposed to play an important role in the solving of the main problem of today food for the world's growing population. The article presents data on the rate of population increase, the size of food production and yields of the most important crop plants. The relationship between the photosynthetic productivity of C3 and C4 plants and their yields is discussed. The problem of the rising atmospheric CO2 concentration and its influence on photosynthesis, photorespiration and accumulation of plant biomass is presented.

  4. Treatment Preferences for CAM in children with chronic pain.

    Science.gov (United States)

    Tsao, Jennie C I; Meldrum, Marcia; Kim, Su C; Jacob, Margaret C; Zeltzer, Lonnie K

    2007-09-01

    CAM therapies have become increasingly popular in pediatric populations. Yet, little is known about children's preferences for CAM. This study examined treatment preferences in chronic pediatric pain patients offered a choice of CAM therapies for their pain. Participants were 129 children (94 girls) (mean age = 14.5 years +/- 2.4; range = 8-18 years) presenting at a multidisciplinary, tertiary clinic specializing in pediatric chronic pain. Bivariate and multivariate analyses were used to examine the relationships between CAM treatment preferences and patient's sociodemographic and clinical characteristics, as well as their self-reported level of functioning. Over 60% of patients elected to try at least one CAM approach for pain. The most popular CAM therapies were biofeedback, yoga and hypnosis; the least popular were art therapy and energy healing, with craniosacral, acupuncture and massage being intermediate. Patients with a diagnosis of fibromyalgia (80%) were the most likely to try CAM versus those with other pain diagnoses. In multivariate analyses, pain duration emerged as a significant predictor of CAM preferences. For mind-based approaches (i.e. hypnosis, biofeedback and art therapy), pain duration and limitations in family activities were both significant predictors. When given a choice of CAM therapies, this sample of children with chronic pain, irrespective of pain diagnosis, preferred non-invasive approaches that enhanced relaxation and increased somatic control. Longer duration of pain and greater impairment in functioning, particularly during family activities increased the likelihood that such patients agreed to engage in CAM treatments, especially those that were categorized as mind-based modalities. PMID:17965769

  5. Treatment Preferences for CAM in Children with Chronic Pain

    Directory of Open Access Journals (Sweden)

    Jennie C. I. Tsao

    2007-01-01

    Full Text Available CAM therapies have become increasingly popular in pediatric populations. Yet, little is known about children's preferences for CAM. This study examined treatment preferences in chronic pediatric pain patients offered a choice of CAM therapies for their pain. Participants were 129 children (94 girls (mean age = 14.5 years ± 2.4; range = 8–18 years presenting at a multidisciplinary, tertiary clinic specializing in pediatric chronic pain. Bivariate and multivariate analyses were used to examine the relationships between CAM treatment preferences and patient's sociodemographic and clinical characteristics, as well as their self-reported level of functioning. Over 60% of patients elected to try at least one CAM approach for pain. The most popular CAM therapies were biofeedback, yoga and hypnosis; the least popular were art therapy and energy healing, with craniosacral, acupuncture and massage being intermediate. Patients with a diagnosis of fibromyalgia (80% were the most likely to try CAM versus those with other pain diagnoses. In multivariate analyses, pain duration emerged as a significant predictor of CAM preferences. For mind-based approaches (i.e. hypnosis, biofeedback and art therapy, pain duration and limitations in family activities were both significant predictors. When given a choice of CAM therapies, this sample of children with chronic pain, irrespective of pain diagnosis, preferred non-invasive approaches that enhanced relaxation and increased somatic control. Longer duration of pain and greater impairment in functioning, particularly during family activities increased the likelihood that such patients agreed to engage in CAM treatments, especially those that were categorized as mind-based modalities.

  6. Can miscanthus C4 photosynthesis compete with festulolium C3 photosynthesis in a temperate climate?

    DEFF Research Database (Denmark)

    Jiao, Xiurong; Sørensen, Kirsten Kørup; Andersen, Mathias Neumann;

    2016-01-01

    Miscanthus, a perennial grass with C4 photosynthesis, is regarded as a promising energy crop due to its high biomass productivity. Compared with other C4 species, most miscanthus genotypes have high cold tolerances at 14 °C. However, in temperate climates, temperatures below 14 °C are common and...... each temperature level and still maintained photosynthesis after growing for a longer period at 6/4 °C. Only two of five measured miscanthus genotypes increased photosynthesis immediately after the temperature was raised again. The photosynthetic capacity of festulolium was significantly higher at 10...

  7. Complementary and alternative medicine (CAM providers’ views of chronic low back pain patients’ expectations of CAM therapies: a qualitative study

    Directory of Open Access Journals (Sweden)

    Schafer Lisa M

    2012-11-01

    Full Text Available Abstract Background Some researchers think that patients with higher expectations for CAM therapies experience better outcomes and that enthusiastic providers can enhance treatment outcomes. This is in contrast to evidence suggesting conventional medical providers often reorient patient expectations to better match what providers believe to be realistic. However, there is a paucity of research on CAM providers’ views of their patients’ expectations regarding CAM therapy and the role of these expectations in patient outcomes. Methods To better understand how CAM providers view and respond to their patients’ expectations of a particular therapy, we conducted 32 semi-structured, qualitative interviews with acupuncturists, chiropractors, massage therapists and yoga instructors identified through convenience sampling. Interviews were recorded, transcribed and analyzed thematically using Atlas ti version 6.1. Results CAM providers reported that they attempt to ensure that their patients’ expectations are realistic. Providers indicated they manage their patients’ expectations in a number of domains— roles and responsibilities of providers and patients, treatment outcomes, timeframe for improvement, and treatment experience. Providers reported that patients’ expectations change over time and that they need to continually manage these expectations to enhance patient engagement and satisfaction with treatment. Conclusions Providers of four types of CAM therapies viewed patients’ expectations as an important component of their experiences with CAM therapy and indicated that they try to align patient expectations with reality. These findings suggest that CAM providers are similar in this respect to conventional medical providers.

  8. Underwater Photosynthesis of Submerged Plants – Recent Advances and Methods

    OpenAIRE

    PEDERSEN, OLE; Colmer, Timothy D.; Sand-Jensen, Kaj

    2013-01-01

    We describe the general background and the recent advances in research on underwater photosynthesis of leaf segments, whole communities, and plant dominated aquatic ecosystems and present contemporary methods tailor made to quantify photosynthesis and carbon fixation under water. The majority of studies of aquatic photosynthesis have been carried out with detached leaves or thalli and this selectiveness influences the perception of the regulation of aquatic photosynthesis. We thus recommend a...

  9. Challenges in Understanding Photosynthesis in a University Introductory Biosciences Class

    Science.gov (United States)

    Södervik, Ilona; Virtanen, Viivi; Mikkilä-Erdmann, Mirjamaija

    2015-01-01

    University students' understanding of photosynthesis was examined in a large introductory biosciences class. The focus of this study was to first examine the conceptions of photosynthesis among students in class and then to investigate how a certain type of text could enhance students' understanding of photosynthesis. The study was based on pre-…

  10. Ecological Understanding 1: Ways of Experiencing Photosynthesis.

    Science.gov (United States)

    Carlsson, Britta

    2002-01-01

    Investigates 10 student teachers' understanding of the different ways in which the function of the ecosystem could be experienced. Explores the functional aspects of the ecosystem using a system approach. Concludes that the idea of transformation is crucial to more complex ways of understanding photosynthesis. (Contains 62 references.) (Author/YDS)

  11. Scaling and Integration of Kinetic Models of Photosynthesis.Towards Comprehensive E-Photosynthesis

    Czech Academy of Sciences Publication Activity Database

    Nedbal, Ladislav; Červený, Jan; Schmidt, H.

    Dordrecht: Springer, 2009 - (Laisk, A.; Nedbal, L.; Govindjee), s. 17-28 ISBN 978-1-4020-9236-7 Institutional research plan: CEZ:AV0Z60870520 Keywords : complexity * mathematical models * photosynthesis * dimensionality reduction * silico Subject RIV: EF - Botanics

  12. Immediate CAD/ CAM Custom Fabricated Dental Implants

    Directory of Open Access Journals (Sweden)

    Jafar Kolahi

    2010-11-01

    Full Text Available Introduction: There will almost always be gaps between cylin-drical or screw shaped prefabricated implant surface and funnel-shaped tooth socket when an implant is placed immediately after tooth extraction. Hence expensive and difficult bone grafting is re-quired. A custom fabricated implant will be a pragmatic solution for this limitation.The hypothesis: First step following extraction of a tooth is data capture or scanning via a 3D scan method e.g. coordinate measuring machine or non-contact laser scanners such as triangulation range finder. Second step is reconstruction or modeling via editable CAD (computer-aided design model, allowing us to add retentive holes and correction of implant angle. Third step is fabrication via CAM (computer aided manufacturing followed by plasma cleaning process. Fourth step is insertion of the CAD/CAM custom fabricated one-stage implant in the fresh tooth socket. Optimal time for this step is 24-48 hours after extraction. The custom fabricated implant should not load 3-4 months. Usage of chlorhexidine mouth-rinse or chewing gum twice daily for 2 weeks and, in some cases oral antibiotic is recommended. Evaluation of the hypothesis: Contemporary dental implant system faced with several clinical and anatomical limitations such is low sinuses or nerve bundles. Complex and expensive surgical procedures such as nerve repositioning and sinus lift are frequently required. With custom fabricated implant we can overcome several of these limitations because insertion of custom fabricated implant will perform before alveolar bone recession.

  13. Predicting photosynthesis and transpiration responses to ozone: decoupling modeled photosynthesis and stomatal conductance

    OpenAIRE

    D. Lombardozzi; Levis, S.; G. Bonan; Sparks, J. P.

    2012-01-01

    Plants exchange carbon dioxide and water, two key greenhouse gases, with the atmosphere through the processes of photosynthesis and transpiration, making them essential in climate regulation. Carbon dioxide and water exchange are typically coupled through the control of stomatal conductance, and the parameterization in many models often predict conductance based on photosynthesis values. Some environmental conditions, like exposure to high ozone (O3) concentrations, alt...

  14. Cam Profile Grinding CNC System Based on Open Architecture

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    This paper studies some key technologies of CNC system for cam grinding. Themathematical motion model for cam grinding is established according to the harmony of re-ciprocating motion of the grinding wheel and the rotating motion of the woorkpiece. Themethod of using the linear servomotor to accomplish the grinding wheel tracking is devel-oped and the dynamic model of the system is analyzed. Then the cross-coupled biaxial errorcompensation model is proposed. Finally,the hardware and software of the control systemare designed based on open architecture. Some algorithms, such as spline fitting and inter-polation for cam contour, velocity control and feed control, are presented to improvegrinding precision.

  15. UVAJANJE PROGRAMSKIH ORODIJ CAD/CAM V PODJETJU

    OpenAIRE

    Gjerkeš, Srečko

    2010-01-01

    V diplomskem delu je prikazan postopek uvedbe CAD/CAM programskega orodja v podjetje. Cilj diplomskega dela je primerjava med ročnim programiranjem in programiranjem s pomočjo CAM sistema ter povečanje produktivnosti proizvodnje pri izdelavi serijskih izdelkov. Z uvedbo programskega orodja bi predvsem skrajšali obdelovalne čase izdelkov, ki se izdelujejo v različnih serijah. Diplomsko delo opisuje osnovne značilnosti CAD/CAM sistemov, podjetje Medicop d.o.o, programska orodja in njihovo p...

  16. SODOBNA RAČUNALNIŠKA TEHNOLOGIJA ZA CAD/CAM

    OpenAIRE

    Herženjak, Eric

    2011-01-01

    Sodobna računalniška tehnologija CAD/CAM se čedalje pogosteje uporablja v naprednih podjetjih v tujini in tudi v Sloveniji. Pomembno je vedeti kakšna aparaturna oprema za CAD/CAM je danes na voljo, saj omogoča uspešno konstruiranje, modeliranje in simulacije. V prvem delu diplomske naloge sem zato preučil sodobno programsko in aparaturno opremo za CAD/CAM, ki je namenjena za konstruiranje, modeliranje in simulacije. Prav tako sem na kratko opisal najpomembnejše vidike dodajanih tehnologij, ki...

  17. CAD/CAM ceramic restorations in the operatory and laboratory.

    Science.gov (United States)

    Fasbinder, Dennis J

    2003-08-01

    Computer assisted design/computer assisted machining (CAD/CAM) technology has received considerable clinical and research interest from modern dental practices as a means of delivering all-ceramic restorations. The CEREC, System offers CAD/CAM dental technology designed for clinical use by dentists, as well as a separate system designed for dental laboratory technicians. The CEREC 3 system is indicated for dental operatory applications, and the CEREC inLab, system is indicated for dental laboratory applications. Although both systems rely on similar CAD/CAM technology, several significant differences exist in the processing techniques involved, restorative materials used, and types of restoration provided. PMID:14692164

  18. CAD/CAM approach to improving industry productivity gathers momentum

    Science.gov (United States)

    Fulton, R. E.

    1982-01-01

    Recent results and planning for the NASA/industry Integrated Programs for Aerospace-Vehicle Design (IPAD) program for improving productivity with CAD/CAM methods are outlined. The industrial group work is being mainly done by Boeing, and progress has been made in defining the designer work environment, developing requirements and a preliminary design for a future CAD/CAM system, and developing CAD/CAM technology. The work environment was defined by conducting a detailed study of a reference design process, and key software elements for a CAD/CAM system have been defined, specifically for interactive design or experiment control processes. Further work is proceeding on executive, data management, geometry and graphics, and general utility software, and dynamic aspects of the programs being developed are outlined

  19. Resin-composite Blocks for Dental CAD/CAM Applications

    Science.gov (United States)

    Ruse, N.D.; Sadoun, M.J.

    2014-01-01

    Advances in digital impression technology and manufacturing processes have led to a dramatic paradigm shift in dentistry and to the widespread use of computer-aided design/computer-aided manufacturing (CAD/CAM) in the fabrication of indirect dental restorations. Research and development in materials suitable for CAD/CAM applications are currently the most active field in dental materials. Two classes of materials are used in the production of CAD/CAM restorations: glass-ceramics/ceramics and resin composites. While glass-ceramics/ceramics have overall superior mechanical and esthetic properties, resin-composite materials may offer significant advantages related to their machinability and intra-oral reparability. This review summarizes recent developments in resin-composite materials for CAD/CAM applications, focusing on both commercial and experimental materials. PMID:25344335

  20. IGES data exchange between dissimilar CAD-CAM systems

    Energy Technology Data Exchange (ETDEWEB)

    Theilen, D.F.

    1982-06-01

    Sandia National Laboratories and Bendix Kansas City have successfully transferred geometrical model data by using a neutral graphics format, Initial Graphics Exchange Specification (IGES). Data was exchanged between two dissimilar CAD-CAM systems without the need for special translators. The exchanged data was used to fabricate a mechanical part. Design information developed on a CAD-CAM system was translated to IGES with a commercial preprocessor at Sandia. A second vendor's postprocessor translated the design information from IGES to the CAD-CAM system at Bendix. The Bendix CAD-CAM system was used to generate the numerical control tape from the exchange data. The tape was used to fabricate the part. A production print from Sandia was used during final inspection to verify part accuracy. Project results indicated that both vendor-furnished translators correctly transferred the geometric model of points, lines and arcs.

  1. Selecting a CAD/CAM system for the first time

    Energy Technology Data Exchange (ETDEWEB)

    Link, C.H.

    1984-01-01

    A good percentage of manufacturing companies with gross sales exceeding $100 million already use some form of computer-aided design and manufacturing (CAD/CAM). More recently, however, a new, larger group with annual gross sales between $10 million and $100 million have entered the CAD/CAM marketplace. Interested because the technology has proven itself to be economical, beneficial, and relatively easy to implement without prior computer experience, these companies are actively investigating and applying CAD and CAD/CAM. Many are subcontractors to large companies with low design requirements. Others may design and/or manufacture a proprietary product line. Yet, while resembling one another, the needs of these companies vary widely. Applying the proper kind and level of CAD/CAM, therefore, requires a careful analysis of each user's needs.

  2. Surgical hip dislocation for treatment of cam femoroacetabular impingement

    Directory of Open Access Journals (Sweden)

    Milind M Chaudhary

    2015-01-01

    Conclusion: Cam femoroacetabular Impingement causing pain and limitation of hip movements was treated by open osteochondroplasty after surgical hip dislocation. This reduced pain, improved hip motion and gave good to excellent results in the short term.

  3. Engine testing of ceramic cam-roller followers

    Energy Technology Data Exchange (ETDEWEB)

    Kalish, Y. (Detroit Diesel Corp., MI (United States))

    1992-04-01

    For several years, DDC has been developing monolithic ceramic heat engine components. One of the components, developed for an application in our state-of-the-art on-highway, heavy-duty diesel engine, the Series 60, is a silicon nitride cam-roller follower. Prior to starting this program, each valve train component in the Series 60 was considered for conversion to a ceramic material. Many advantages and disadvantages (benefits and risks) were considered. From this effort, one component was selected, the cam-roller follower. Using a system design approach, a ceramic cam-roller follower offered functional improvement at a reasonable cost. The purpose of the project was to inspect and test 100 domestically produced silicon nitride cam-roller followers built to the requirements of the DDC series 60 engine.

  4. Engine testing of ceramic cam-roller followers. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kalish, Y. [Detroit Diesel Corp., MI (United States)

    1992-04-01

    For several years, DDC has been developing monolithic ceramic heat engine components. One of the components, developed for an application in our state-of-the-art on-highway, heavy-duty diesel engine, the Series 60, is a silicon nitride cam-roller follower. Prior to starting this program, each valve train component in the Series 60 was considered for conversion to a ceramic material. Many advantages and disadvantages (benefits and risks) were considered. From this effort, one component was selected, the cam-roller follower. Using a system design approach, a ceramic cam-roller follower offered functional improvement at a reasonable cost. The purpose of the project was to inspect and test 100 domestically produced silicon nitride cam-roller followers built to the requirements of the DDC series 60 engine.

  5. Today's CAD/CAM: flexible digital technologies expanding workflow options.

    Science.gov (United States)

    Ferencz, Jonathan L

    2015-03-01

    CAD/CAM and digital scanning technologies have become essential components of dentistry. Digital impression scanning, restoration design, and manufacturing techniques yield greater treatment predictability, high-level esthetics, and functional accuracy using a variety of materials. PMID:25822749

  6. CAD-CAM Implants in Esthetic and Reconstructive Craniofacial Surgery

    OpenAIRE

    Hendricks, Jörg; Hemprich, Alexander; Schulze, Fritz Peter; Berti, Guntram; Schmidt, Jens-Georg; Scholz, Eckhard; Wollny, Gerd; Hierl, Thomas

    2006-01-01

    In the reconstruction of complex craniofacial malformations CAD-CAM procedures could help generating alloplastic implants to achieve almost optimal esthetic results. Complementary to the existing CAD-CAM techniques in the cranial vault region or modeling procedures in unilateral defects, these techniques are introduced to bilaterally affected skulls in esthetic reconstructive surgery. Surgery could thus become less invasive and results more predictable. A tool chain is shown to generate such ...

  7. Geometric Distortion Analysis Using CAD/CAM Based Manufacturing Simulation

    OpenAIRE

    Werke, Mats; Hedlind, Mikael; Nicolescu, Mihai

    2014-01-01

    Machining of components may cause geometric distortions and thereby quality issues and increased costs. This paper presents an engineering approach of CAD/CAM based manufacturing simulation in order to be in control of geometric distortions after machining. The method utilises STEP AP209 for communication of CAD/CAM simulation data. The method improves the ability to optimise process parameters, geometry, and material, in order to fulfil the design requirements. The method supports concurrent...

  8. Availability Analysis of the Ventilation Stack CAM Interlock System

    International Nuclear Information System (INIS)

    Ventilation Stack Continuous Air Monitor (CAM) Interlock System failure modes, failure frequencies, and system availability have been evaluated for the RPP. The evaluation concludes that CAM availability is as high as assumed in the safety analysis and that the current routine system surveillance is adequate to maintain this availability credited in the safety analysis, nor is such an arrangement predicted to significantly improve system availability

  9. A systematic review of CAD/CAM fit restoration evaluations.

    Science.gov (United States)

    Boitelle, P; Mawussi, B; Tapie, L; Fromentin, O

    2014-11-01

    The evolution and development of CAD/CAM systems have led to the production of prosthetic reconstructions by going beyond the use of traditional techniques. Precision adjustment of prosthetic elements is considered essential to ensure sustainable restoration and dental preparation. The purpose of this article was to summarise the current literature on the fitting quality of fixed prostheses obtained by CAD/CAM technology. PMID:24952991

  10. Operation of the xanthophyll cycle and degradation of D1 protein in the inducible CAM plant, Talinum triangulare, under water deficit.

    Science.gov (United States)

    Pieters, Alejandro J; Tezara, Wilmer; Herrera, Ana

    2003-09-01

    Changes in photochemical activity induced by water deficit were investigated in Talinum triangulare, an inducible CAM plant. The aim was to analyse the interactions between C3 photosynthesis, induction and activity of CAM, photosynthetic energy regulation and the mechanisms responsible for photoprotection and photoinhibition under water stress. Gas exchange, chlorophyll a fluorescence, titratable acidity, carotenoid composition and relative contents of the PSII reaction centre protein (D1) were measured. A decrease in xylem tension (psi) from -0.14 to -0.2 MPa substantially decreased daytime net CO2 assimilation and daily carbon gain, and induced CAM, as shown by CO2 assimilation during the night and changes in titratable acidity; a further decrease in psi decreased nocturnal acid accumulation by 60%. Non-photochemical quenching of chlorophyll a fluorescence (NPQ) increased with water deficit, but decreased with a more severe drought (psi below -0.2 MPa), when CAM activity was low. NPQ was lower at 0900 h (during maximum decarboxylation rates) than at 1400 h, when malate pools were depleted. Down-regulation of PSII activity related to the rise in NPQ was indicated by a smaller quantum yield of PSII photochemistry (phiPSII) in droughted compared with watered plants. However, phiPSII was larger at 0900 h than at 1400 h. The de-epoxidation state of the xanthophyll cycle increased with drought and was linearly related to NPQ. Intrinsic quantum yield of PSII (FV/FM) measured at dusk was also lower in severely stressed plants than in controls. Under maximum photosynthetic photon flux and high decarboxylation rates of organic acids, the D1 content in leaves of droughted plants showing maximal CAM activity was identical to the controls; increased drought decreased D1 content by more than 30%. Predawn samples had D1 contents similar to leaves sampled at peak irradiance, with no signs of recovery after 12 h of darkness. It is concluded that under mild water stress, early

  11. Toxicity of pesticides on photosynthesis of diatoms

    International Nuclear Information System (INIS)

    Pakistan being an agricultural country, a large amount of pesticides are used, including organophosphates and synthetic pyrethroids. These pesticides are released through rivers and other tributeries into the coastal environment, thus posing a contiguous threat to marine organisms. In the present study two species of diatoms Amphora and Navicula were selected for the assessment of impact of organ phosphate and pyrethroid toxicity on these primary producers. The study shows that rate of photosynthesis was inhibited in both Amphora and Navicula species exposed to pesticide. The acute toxicity of pesticide was determined by measuring IC50 of the test organisms. IC50 calculated for diatom species depicts that different pesticides had variable effects on the photosynthesis of microalgae. High sensitivity of marine organisms is alarming as it may have implications on the marine ecosystem and fisheries. The results are also useful in setting control limits for the release of these chemicals in nature. (author)

  12. Moessbauer spectroscopy in studies of photosynthesis

    International Nuclear Information System (INIS)

    Photosynthesis is a process occurring in certain species of bacteria, algae and higher plants. It transforms solar energy into various forms of energy-rich organic molecules. Photosystem II (PSII) is the 'heart' of the photosynthetic apparatus because it delivers electrons and protons for further steps of the light-driven phases of photosynthesis. There are two enigmatic iron binding structures within the core of photosynthetic apparatus, which play an important role in the electron transfer within PSII. Many investigations focus on the determination of their function which is the key to the understanding of the molecular mechanism of the energy and electron transfer within PSII. Among many methods used in this research field, the Moessbauer spectroscopy is a unique one, which gives the possibility to study changes of the valence and spin states of those two iron sites and the dynamical properties of their protein matrix in the presence of various physiological and stress conditions.

  13. A quantum protective mechanism in photosynthesis

    CERN Document Server

    Marais, Adriana; Petruccione, Francesco; van Grondelle, Rienk

    2016-01-01

    Since the emergence of oxygenic photosynthesis, living systems have developed protective mechanisms against reactive oxygen species. During charge separation in photosynthetic reaction centres, triplet states can react with molecular oxygen generating destructive singlet oxygen. The triplet product yield in bacteria is observed to be reduced by weak magnetic fields. Reaction centres from plants' photosystem II share many features with bacterial reaction centres, including a high-spin iron whose function has remained obscure. To explain observations that the magnetic field effect is reduced by the iron, we propose that its fast-relaxing spin plays a protective role in photosynthesis by generating an effective magnetic field. We consider a simple model of the system, derive an analytical expression for the effective magnetic field and analyse the resulting triplet yield reduction. The protective mechanism is robust for realistic parameter ranges, constituting a clear example of a quantum effect playing a macros...

  14. CAD-CAM at Bendix Kansas city: the BICAM system

    Energy Technology Data Exchange (ETDEWEB)

    Witte, D.R.

    1983-04-01

    Bendix Kansas City Division (BEKC) has been involved in Computer Aided Manufacturing (CAM) technology since the late 1950's when the numerical control (N/C) analysts installed computers to aid in N/C tape preparation for numerically controlled machines. Computer Aided Design (CAD) technology was introduced in 1976, when a number of 2D turnkey drafting stations were procured for printed wiring board (PWB) drawing definition and maintenance. In June, 1980, CAD-CAM Operations was formed to incorporate an integrated CAD-CAM capability into Bendix operations. In March 1982, a ninth division was added to the existing eight divisions at Bendix. Computer Integrated Manufacturing (CIM) is a small organization, reporting directly to the general manager, who has responsibility to coordinate the overall integration of computer aided systems at Bendix. As a long range plan, CIM has adopted a National Bureau of Standards (NBS) architecture titled Factory of the Future. Conceptually, the Bendix CAD-CAM system has a centrally located data base which can be accessed by both CAD and CAM tools, processes, and personnel thus forming an integrated Computer Aided Engineering (CAE) System. This is a key requirement of the Bendix CAD-CAM system that will be presented in more detail.

  15. Manganese and the Evolution of Photosynthesis

    Science.gov (United States)

    Fischer, Woodward W.; Hemp, James; Johnson, Jena E.

    2015-09-01

    Oxygenic photosynthesis is the most important bioenergetic event in the history of our planet—it evolved once within the Cyanobacteria, and remained largely unchanged as it was transferred to algae and plants via endosymbiosis. Manganese plays a fundamental role in this history because it lends the critical redox behavior of the water-oxidizing complex of photosystem II. Constraints from the photoassembly of the Mn-bearing water-oxidizing complex fuel the hypothesis that Mn(II) once played a key role as an electron donor for anoxygenic photosynthesis prior to the evolution of oxygenic photosynthesis. Here we review the growing body of geological and geochemical evidence from the Archean and Paleoproterozoic sedimentary records that supports this idea and demonstrates that the oxidative branch of the Mn cycle switched on prior to the rise of oxygen. This Mn-oxidizing phototrophy hypothesis also receives support from the biological record of extant phototrophs, and can be made more explicit by leveraging constraints from structural biology and biochemistry of photosystem II in Cyanobacteria. These observations highlight that water-splitting in photosystem II evolved independently from a homodimeric ancestral type II reaction center capable of high potential photosynthesis and Mn(II) oxidation, which is required by the presence of homologous redox-active tyrosines in the modern heterodimer. The ancestral homodimer reaction center also evolved a C-terminal extension that sterically precluded standard phototrophic electron donors like cytochrome c, cupredoxins, or high-potential iron-sulfur proteins, and could only complete direct oxidation of small molecules like Mn2+, and ultimately water.

  16. Photosynthesis/translocation studies in terrestrial ecosystems

    International Nuclear Information System (INIS)

    In this chapter, the basic methods of 14C use in plant science are presented with three examples of applications in the field of plant physiology and ecology. Since environmental factors play a major role in the rates of photosynthesis and translocation processes, a majority of the chapter is devoted to the description of methods and technologies involved to maintain normal growth conditions for the plants used for 14C experiments

  17. A quantum protective mechanism in photosynthesis

    OpenAIRE

    Adriana Marais; Ilya Sinayskiy; Francesco Petruccione; Rienk van Grondelle

    2015-01-01

    Since the emergence of oxygenic photosynthesis, living systems have developed protective mechanisms against reactive oxygen species. During charge separation in photosynthetic reaction centres, triplet states can react with molecular oxygen generating destructive singlet oxygen. The triplet product yield in bacteria is observed to be reduced by weak magnetic fields. Reaction centres from plants' photosystem II share many features with bacterial reaction centres, including a high-spin iron who...

  18. Energy Conversion in Natural and Artificial Photosynthesis

    OpenAIRE

    McConnell, Iain; Li, Gonghu; Brudvig, Gary W.

    2010-01-01

    Modern civilization is dependent upon fossil fuels, a nonrenewable energy source originally provided by the storage of solar energy. Fossil fuel dependence has severe consequences including energy security issues and greenhouse gas emissions. The consequences of fossil fuel dependence could be avoided by fuel-producing artificial systems that mimic natural photosynthesis, directly converting solar energy to fuel. This review describes the three key components of solar energy conversion in pho...

  19. Modelling the fast fluorescence rise of photosynthesis

    OpenAIRE

    Baake, Ellen; Schlöder, Johannes P.

    1992-01-01

    We construct an ODE model for the fast fluorescence rise of photosynthesis by combining the current reaction scheme of the PS II two-electron-gate with a quasi steady-state description of the fast processes of excitation energy transfer and primary charge separation. The model is fitted to measured induction curves with a multiple shooting algorithm, and remarkably good approximations of the data are obtained. Model refinements are discussed focusing on PS II heterogeneity, and on PS I.

  20. Response of photosynthesis to ocean acidification

    OpenAIRE

    Mackey, KRM; Morris, JJ; Morel, FMM; Kranz, SA

    2015-01-01

    © 2015 by The Oceanography Society. All rights reserved. All phytoplankton and higher plants perform photosynthesis, where carbon dioxide is incorporated into biomass during cell growth. Ocean acidification (OA) has the potential to affect photosynthetic kinetics due to increasing seawater pCO2 levels and lower pH. The effects of increased CO2 are difficult to predict because some species utilize carbon concentrating mechanisms that buffer their sensitivity to ambient CO2 levels and require v...

  1. Response of Photosynthesis to Ocean Acidification

    OpenAIRE

    Katherine R.M. Mackey; J. Jeffrey Morris; Morel, François M. M.; Kranz, Sven A.

    2015-01-01

    All phytoplankton and higher plants perform photosynthesis, where carbon dioxide is incorporated into biomass during cell growth. Ocean acidification (OA) has the potential to affect photosynthetic kinetics due to increasing seawater pCO2 levels and lower pH. The effects of increased CO2 are difficult to predict because some species utilize carbon concentrating mechanisms that buffer their sensitivity to ambient CO2 levels and require variable energy investments. Here, we discuss the current ...

  2. Photosynthesis and the world food problem

    OpenAIRE

    Jerzy Poskuta

    2014-01-01

    Studies in the field of photosynthesis are particularly predisposed to play an important role in the solving of the main problem of today food for the world's growing population. The article presents data on the rate of population increase, the size of food production and yields of the most important crop plants. The relationship between the photosynthetic productivity of C3 and C4 plants and their yields is discussed. The problem of the rising atmospheric CO2 concentration and its influence ...

  3. Automated photosynthesis of 11C-glucose

    International Nuclear Information System (INIS)

    Glucose and fructose, labelled with 11C, were produced by passing 11CO2 into an evacuated chamber containing spinach leaves. Photosynthesis was carried out by day light lamp illumination. 75-95% of the 11CO2 was absorbed by the leaves and the radioactivity in the leaves was extracted in ethanol as sugars. Radiochemical purity was determined by HPLC. The automated system was controlled by timers. (U.K.)

  4. Evidence of Drought Stress Memory in the Facultative CAM, Aptenia cordifolia: Possible Role of Phytohormones.

    Directory of Open Access Journals (Sweden)

    Eva Fleta-Soriano

    Full Text Available Although plant responses to drought stress have been studied in detail in several plant species, including CAM plants, the occurrence of stress memory and possible mechanisms for its regulation are still very poorly understood. In an attempt to better understand the occurrence and possible mechanisms of regulation of stress memory in plants, we measured the concentrations of phytohormones in Aptenia cordifolia exposed to reiterated drought, together with various stress indicators, including leaf water contents, photosynthesis and mechanisms of photo- and antioxidant protection. Results showed that plants exposed to drought stress responded differently if previously challenged with a first drought. Gibberellin levels decreased upon exposure to the first drought and remained lower in double-stressed plants compared with those exposed to stress for the first time. In contrast, abscisic acid levels were higher in double- than single-stressed plants. This occurred in parallel with alterations in hydroperoxide levels, but not with malondialdehyde levels, thus suggesting an increased oxidation state that did not result in oxidative damage in double-stressed plants. It is concluded that (i drought stress memory occurs in double-stressed A. cordifolia plants, (ii both gibberellins and abscisic acid may play a role in plant response to repeated periods of drought, and (iii changes in abscisic acid levels in double-stressed plants may have a positive effect by modulating changes in the cellular redox state with a role in signalling, rather than cause oxidative damage to the cell.

  5. Transcriptome Analysis of Drought-Tolerant CAM plants Agave deserti and Agave tequilana

    Energy Technology Data Exchange (ETDEWEB)

    Gross, Stephen M.; Martin, Jeffrey A.; Simpson, June; Wang, Zhong; Visel, Axel

    2013-03-25

    Agaves are succulent monocotyledonous plants native to hot and arid environments of North America. Because of their adaptations to their environment, including crassulacean acid metabolism (CAM, a water-efficient form of photosynthesis) and existing technologies for ethanol production, agaves have gained attention both as potential lignocellulosic bioenergy feedstocks and models for exploring plant responses to abiotic stress. However, the lack of comprehensive Agave sequence datasets limits the scope of investigations into the molecular-genetic basis of Agave traits. Here, we present comprehensive, high quality de novo transcriptome assemblies of two Agave species, A. tequilana and A. deserti, from short-read RNA-seq data. Our analyses support completeness and accuracy of the de novo transcriptome assemblies, with each species having approximately 35,000 protein-coding genes. Comparison of agave proteomes to those of additional plant species identifies biological functions of gene families displaying sequence divergence in agave species. Additionally, we use RNA-seq data to gain insights into biological functions along the A. deserti juvenile leaf proximal-distal axis. Our work presents a foundation for further investigation of agave biology and their improvement for bioenergy development.

  6. Bendix CAD-CAM site plan

    Energy Technology Data Exchange (ETDEWEB)

    Smith, M.L.

    1982-12-01

    The Bendix Site Plan for CAD-CAM encompasses the development and integration of interactive graphics systems, factory data management systems, robotics, direct numerical control, automated inspection, factory automation, and shared data bases to achieve significant plant-wide gains in productivity. This plan does not address all current or planned computerization projects within our facility. A summary of planning proposals and rationale is presented in the following paragraphs. Interactive Graphics System (IGS) capability presently consists of two Applicon CAD systems and the CD-2000 software program processing on a time-shared CYBER 174 computer and a dedicated CYBER 173. Proposed plans include phased procurment through FY85 of additional computers and sufficient graphics terminals to support projected needs in drafting, tool/gage design, N/C programming, and process engineering. Planned procurement of additional computer equipment in FY86 and FY87 will provide the capacity necessary for a comprehensive graphics data base management system, computer-aided process planning graphics, and special graphics requirements in facilities and test equipment design. The overall IGS plan, designated BICAM (Bendix Integrated Computer Aided Manufacturing), will provide the capability and capacity to integrate manufacturing activities through a shared product data base and standardized data exchange format. Planned efforts in robotics will result in productive applications of low to medium technology robots beginning in FY82, and extending by FY85 to work cell capabilities utilizing higher technology robots with sensors such as vision and instrumented remote compliance devices. A number of robots are projected to be in service by 1990.

  7. Wild Manihot Species Do Not Possess C4 Photosynthesis

    OpenAIRE

    CALATAYUD, P.‐A.; BARÓN, C. H.; VELÁSQUEZ, H.; ARROYAVE, J. A.; LAMAZE, T.

    2002-01-01

    Cultivated cassava (Manihot esculenta) has a higher rate of photosynthesis than is usual for C3 plants and photosynthesis is not light saturated. For these reasons it has been suggested that cultivated cassava could be derived from wild species possessing C4 photosynthesis. The natural abundance of 13C and activities of phosphoenolpyruvate carboxylase and phosphoglycolate phosphatase were measured in leaves of 20 wild cassava species to test this hypothesis. All the species studied, including...

  8. Can the photosynthesis first step quantum mechanism be explained?

    OpenAIRE

    Sacilotti, Marco; Almeida, Euclides; Mota, Claudia C. B. O.; Nunes, Frederico Dias; Anderson S. L. Gomes

    2010-01-01

    Photosynthesis first step mechanism concerns the sunlight absorption and both negative and positive charges separation. Recent and important photosynthesis literature claims that this mechanism is quantum mechanics controlled, however without presenting qualitative or quantitative scientifically based mechanism. The present accepted and old-fashioned photosynthesis mechanism model suffers from few drawbacks and an important issue is the absence of driving force for negative and positive charg...

  9. Artificial photosynthesis and the splitting of water to generate hydrogen

    OpenAIRE

    Maitra, Urmimala; Lingampalli, SR; Rao, CNR

    2014-01-01

    It is no exaggeration to state that the energy crisis is the most serious challenge that we face today. Among the strategies to gain access to reliable, renewable energy, the use of solar energy has clearly emerged as the most viable option. A promising direction in this context is artificial photosynthesis. In this article, we briefly describe the essential features of artificial photosynthesis in comparison with natural photosynthesis and point out the modest success that we have had in spl...

  10. Electrical signaling and photosynthesis: Can they co-exist together?

    OpenAIRE

    Pavlovič, Andrej; Mancuso, Stefano

    2011-01-01

    Mechanical irritation of trigger hairs and subsequent generation of action potentials have significant impact on photosynthesis and respiration in carnivorous Venus flytrap (Dionaea muscipula). Action potential-mediated inhibition of photosynthesis and stimulation of respiration is confined only to the trap and was not recorded in adjacent photosynthetic lamina. We showed that the main primary target of electrical signals on assimilation is in the dark enzymatic reaction of photosynthesis. Wi...

  11. EFFECT OF AIR TEMPERATURE ON LEAF PHOTOSYNTHESIS IN ELDER

    Directory of Open Access Journals (Sweden)

    Monica Popescu

    2012-12-01

    Full Text Available Temperature with solar radiation intensity is the main external factor affecting photosynthesis process. Measurements were collected in the 2011 growing season. Photosynthesis and respiration measurements were made at Sambucus nigra leaves with a CO2 analyzer. The aim was to develop a model of photosynthesis in relation to temperature (which is in close relationship with air humidity. Photosynthesis of Sambucus nigra leaves is sensitive to temperature with an optimum around 25-28oC and rates declining by 18% with air temperature around 33-35oC.

  12. Prevalence of Cam Morphology in Females with Femoroacetabular Impingement

    Directory of Open Access Journals (Sweden)

    David M Levy

    2015-12-01

    Full Text Available Cam and pincer are two common morphologies responsible for femoroacetabular impingement. Previous literature has reported that cam deformity is predominantly a male morphology, while being significantly less common in females. The purpose of this study was to determine the prevalence of cam morphology in female subjects diagnosed with symptomatic FAI. All females presenting to the senior author’s clinic diagnosed with symptomatic FAI between December 2006 and Cam and pincer are two common morphologies responsible for femoroacetabular impingement. Previous literature has reported that cam deformity is predominantly a male morphology, while being significantly less common in females. Cam morphology is commonly assessed with the alpha angle, measured on radiographs. The purpose of this study was to determine the prevalence of cam morphology utilizing the alpha angle in female subjects diagnosed with symptomatic FAI. All females presenting to the senior author’s clinic diagnosed with symptomatic FAI between December 2006 and January 2013 were retrospectively reviewed. Alpha (α angles were measured on AP (anteroposterior and lateral (Dunn 90°, cross-table lateral, and/or frog-leg lateral plain radiographs by two blinded physicians, and the largest measured angle was used. Using Gosvig et al.’s classification, alpha angle was characterized as (pathologic > 57°, borderline (51-56°, subtle (46-50°, very subtle (43-45°, or normal (≤42°. Three hundred and ninety-one patients (438 hips were analyzed (age 36.2 ± 12.3 years. Among the hips included, 35.6% were normal, 14.6% pathologic, 15.1% borderline, 14.6% subtle, and 20.1% very subtle. There was no correlation between alpha angle and patient age (R = 0.17 or body mass index (BMI (R = 0.05. The intraclass correlation coefficient (ICC for α-angle measurements was 0.84. Sixty-four percent of females in this cohort had an alpha angle > 42°. Subtle cam deformity plays a significant role in

  13. PRODUCT DATA MANAGEMENT DALAM KAITAN DENGAN CAD/CAM

    Directory of Open Access Journals (Sweden)

    Bernardo Nugroho Yahya

    2004-01-01

    Full Text Available The future industry is the one who can manage the information system. Today, communication technology and distributed system computerization already have the ability to implement system that able to exchange and share information between different users. Product Data Management (PDM is an up-to-date and excellent method on managing the exchange and share of information. PDM is able to integrate and manage data analyzing process and documentation of the related product component physically. By adjusting the CAD/CAM on certain condition, the PDM will function maximally by using the information based on STEP (Standard for the Exchange of Product Data model. This article will explain the relationship between PDM system and CAD/CAM on industry. Abstract in Bahasa Indonesia : Sistem informasi merupakan ujung tombak sebuah perusahaan yang unggul di masa depan. Komputerisasi dengan sistem yang terdistribusi dan teknologi komunikasi saat ini memiliki kemampuan untuk mengimplementasikan sistem yang dapat menukar dan men-share informasi antar user yang berbeda. Teknologi yang mendapat cukup perhatian luas dalam hal pertukaran dan sharing informasi ini adalah Product Data Management (PDM. PDM dapat mengintegrasikan dan mengatur proses pengolahan data dan dokumen teknik yang berhubungan dengan komponen fisik produk yang bersangkutan. PDM akan berfungsi maksimal apabila kesesuaian dengan CAD/CAM diatur sedemikian rupa, dihubungkan dengan informasi berbasiskan STEP (Standard for the Exchange of Product Data model. Artikel ini akan menjelaskan hubungan antara sistem PDM dengan CAD/CAM dalam industri. Kata kunci: PDM, Manajemen Data, CAD/CAM, STEP.

  14. Concerns of Hydrothermal Degradation in CAD/CAM Zirconia

    Science.gov (United States)

    Kim, J.-W.; Covel, N.S.; Guess, P.C.; Rekow, E.D.; Zhang, Y.

    2010-01-01

    Zirconia-based restorations are widely used in prosthetic dentistry; however, their susceptibility to hydrothermal degradation remains elusive. We hypothesized that CAD/CAM machining and subsequent surface treatments, i.e., grinding and/or grit-blasting, have marked effects on the hydrothermal degradation behavior of Y-TZP. CAD/CAM-machined Y-TZP plates (0.5 mm thick), both with and without subsequent grinding with various grit sizes or grit-blasting with airborne alumina particles, were subjected to accelerated aging tests in a steam autoclave. Results showed that the CAD/CAM-machined surfaces initially exhibited superior hydrothermal degradation resistance, but deteriorated at a faster rate upon prolonged autoclave treatment compared with ground and grit-blasted surfaces. The accelerated hydrothermal degradation of CAD/CAM surfaces is attributed to the CAD/CAM machining damage and the absence of surface compressive stresses in the fully sintered material. Clinical relevance for surface treatments of zirconia frameworks in terms of hydrothermal and structural stabilities is addressed. PMID:19966039

  15. Exploring adolescent complementary/alternative medicine (CAM) use in Canada.

    Science.gov (United States)

    Patterson, Chris; Arthur, Heather; Noesgaard, Charlotte; Caldwell, Patricia; Vohra, Julie; Francoeur, Chera; Swinton, Marilyn

    2008-01-01

    A qualitative study using a grounded theory approach investigated adolescents' perceptions about complementary/alternative medicine (CAM) use. Adolescents, attending a clinic at the Canadian College of Naturopathic Medicine, were interviewed after receiving ethics approval. Data were collected using semi-structured interviews. The decision of adolescents to use CAM was based within the context of their world and how it shaped influencing factors. Factors that influenced adolescents' decision to use CAM were identified as certain personality traits, culture, media, social contacts and the ability of CAM providers to develop therapeutic relationships. The barriers and benefits of CAM use influenced evaluation of choices. The importance of barriers in limiting freedom of choice in health care decisions should be investigated by practitioners as they provide care to adolescents. Health care planning for integrative models of care requires determining the "right" blend of expertise by knowing interprofessional boundaries, determining mixed skill sets to provide the essential services and ensuring appropriate regulation that allows practitioners to use their full scope of practice. PMID:18202985

  16. CamBAfx: workflow design, implementation and application for neuroimaging

    Directory of Open Access Journals (Sweden)

    Cinly Ooi

    2009-08-01

    Full Text Available CamBAfx is a workflow application designed for both researchers who use workflows to process data (consumers and those who design them (designers. It provides a front-end (user interface optimized for data processing designed in a way familiar to consumers. The back-end uses a pipeline model to represent workflows since this is a common and useful metaphor used by designers and is easy to manipulate compared to other representations like programming scripts. As an Eclipse Rich Client Platform application, CamBAfx's pipelines and functions can be bundled with the software or downloaded post-installation. The user interface contains all the workflow facilities expected by consumers. Using the Eclipse Extension Mechanism designers are encouraged to customize CamBAfx for their own pipelines. CamBAfx wraps a workflow facility around neuroinformatics software without modification. CamBAfx's design, licensing and Eclipse Branding Mechanism allow it to be used as the user interface for other software, facilitating exchange of innovative computational tools between originating labs.

  17. A Simple Thermodynamic Analysis of Photosynthesis

    Directory of Open Access Journals (Sweden)

    F. Angulo-Brown

    2007-11-01

    Full Text Available In this paper we present a comparative study of nine photosynthetic pathways bymeans of their thermodynamic performance. The comparison is made by using the thermalefficiency of light-to-chemical energy conversion and the so-called ecological criterionarising from finite-time thermodynamics. The application of both criteria leads tophotosynthesis made by metaphytes and non sulfur purple bacteria as those of bestthermodynamic performance. In spite of the simplicity of our thermodynamic approachsome insights over the low overall efficiency of photosynthesis is suggested.

  18. RELATIONSHIPS BETWEEN NITROGEN METABOLISM AND PHOTOSYNTHESIS

    Energy Technology Data Exchange (ETDEWEB)

    Bassham, James A.; Larsen, Peder O.; Lawyer, Arthur L.; Cornwell, Karen L.

    1980-11-01

    This discussion addresses three issues under which investigators in our laboratory can provide some information. These issues are first, the keto acid and amino acid biosynthetic capabilities of the chloroplast; second, the bidirectionality of the glycine-serine interconversion associated with photorespiration or its absence; and third, the complex issue of the regulation of carbon flow from photosynthesis to biosynthesis of starch and sucrose as compared with synthesis of amino acids in the photosynthetic cell. In particular, we will discuss the profound regulatory effects of the addition of low levels of ammonium ion to cell media.

  19. Design of molecular architectures to mimic photosynthesis

    International Nuclear Information System (INIS)

    Our researches on photo-induced energy or electron transfer for artificial photosynthesis relies on the utilization of conjugated spacers to perform these two processes over long distance. This article describes the synthesis and the characterization of dyads composed of a tris-bipyridine ruthenium complex as sensitizer, a fullerene or a naphthalene bis-imide as acceptor and a oligo(phenylene-ethynylene) as spacer. These systems exhibit electron or energy transfer from the excited state of the ruthenium complex to the acceptor. (authors)

  20. Engineering photosynthesis in plants and synthetic microorganisms.

    Science.gov (United States)

    Maurino, Veronica G; Weber, Andreas P M

    2013-01-01

    Photosynthetic organisms, such as cyanobacteria, algae, and plants, sustain life on earth by converting light energy, water, and CO(2) into chemical energy. However, due to global change and a growing human population, arable land is becoming scarce and resources, including water and fertilizers, are becoming exhausted. It will therefore be crucial to design innovative strategies for sustainable plant production to maintain the food and energy bases of human civilization. Several different strategies for engineering improved photosynthesis in crop plants and introducing novel photosynthetic capacity into microorganisms have been reviewed. PMID:23028016

  1. Photosynthesis in Hydrogen-Dominated Atmospheres

    OpenAIRE

    William Bains; Sara Seager; Andras Zsom

    2014-01-01

    The diversity of extrasolar planets discovered in the last decade shows that we should not be constrained to look for life in environments similar to early or present-day Earth. Super-Earth exoplanets are being discovered with increasing frequency, and some will be able to retain a stable, hydrogen-dominated atmosphere. We explore the possibilities for photosynthesis on a rocky planet with a thin H[subscript 2]-dominated atmosphere. If a rocky, H[subscript 2]-dominated planet harbors life, th...

  2. The Path of Carbon in Photosynthesis XIV.

    Science.gov (United States)

    Calvin, Melvin; Bassham, J. A.; Benson, A. A.; Kawaguchi, S.; Lynch, V. H.; Stepka, W.; Tolbert, N. E.

    1951-06-30

    It seems hardly necessary to repeat to an audience of this kind the importance of the process known as photosynthesis in the interaction and the interdependence of organisms and in the very existence of life as we know it. This process by which green plants are able to capture electromagnetic energy in the form of sunlight and transform it into stored chemical energy in the form of a wide variety of reduced (relative to carbon dioxide) carbon compounds provides the only major source of energy for the maintenance and propagation of all life.

  3. Photosynthesis and obtaining hydrogen. Photosynthese und Wasserstoffgewinnung

    Energy Technology Data Exchange (ETDEWEB)

    Kohlhoff, J.

    1989-01-01

    The individual processes of photo synthesis can be divided into groups of primary and secondary reactions. The primary reactions include the processes due to the effect of light and lead to splitting of water to form oxygen and to instituting both and hydrogen store and an energy store. Chlorophyl acts as an absorber and transmitter of light energy. The photolysis of water can only occur with the photons of visible light of relatively low energy, because the photosynthesis reaction centres have membranes which catch the light, collect it (by using its energy to separate electric charges) and this makes a multi-quantum process possible. (orig.).

  4. Photosynthesis "In Silico". Overcoming the Challenges of Photosynthesis Education Using a Multimedia CD-ROM

    Science.gov (United States)

    Russell, A. W.; Netherwood, G. M. A.; Robinson, S. A.

    2004-01-01

    Photosynthesis is a central topic in biology education. It remains one of the most challenging, largely because of a) its conceptual difficulty, leading to lack of interest and misconceptions among students; b) the difficulties students have in visualising the process, or relating it to things they can see, especially when the topic is presented…

  5. Scaling and Integration of Kinetic Models of Photosynthesis.Towards Comprehensive E-Photosynthesis

    Czech Academy of Sciences Publication Activity Database

    Nedbal, Ladislav; Červený, Jan; Schmidt, H.

    Dordrecht: Springer, 2009 - (Laisk, A.; Nedbal, L.; Govindjee), s. 17-29 ISBN 978-1-4020-9236-7 Institutional research plan: CEZ:AV0Z60870520 Keywords : Complexity * Mathematical models * Photosynthesis * in silico * Dimensionality reduction Subject RIV: EH - Ecology, Behaviour

  6. IGES data exchange between dissimilar CAD-CAM systems

    Energy Technology Data Exchange (ETDEWEB)

    Theilen, D.F.; Jones, J.F.

    1982-04-01

    Sandia National Laboratories, Livermore (SNLL), and Bendix Kansas City have successfully transferred geometric model data by using a neutral graphics format, Initial Graphics Exchange Specification (IGES). Data was exchanged between two dissimilar CAD-CAM systems without the need for special translators. The exchanged data was used to fabricate a mechanical part. Design information developed on a CAD-CAM system was translated to IGES with a commercial preprocessor at Sandia. A second vendor's postprocessor translated the design information from IGES to the CAD-CAM system at Bendix. The Bendix system was used to generate the numerical control tape from the exchanged data. The tape was used to fabricate the part. A production print from Sandia was used during final inspection to verify part accuracy. Project results indicated that both vendor-furnished translators correctly transferred the three-dimensional geometric model of points, lines, and arcs.

  7. GravityCam: Higher Resolution Visible Wide-Field Imaging

    CERN Document Server

    Mackay, Craig; Steele, Iain

    2016-01-01

    The limits to the angular resolution achievable with conventional ground-based telescopes are unchanged over 70 years. Atmospheric turbulence limits image quality to typically ~1 arcsec in practice. We have developed a new concept of ground-based imaging instrument called GravityCam capable of delivering significantly sharper images from the ground than is normally possible without adaptive optics. The acquisition of visible images at high speed without significant noise penalty has been made possible by advances in optical and near IR imaging technologies. Images are recorded at high speed and then aligned before combination and can yield a 3-5 fold improvement in image resolution. Very wide survey fields are possible with widefield telescope optics. We describe GravityCam and detail its application to accelerate greatly the rate of detection of Earth size planets by gravitational microlensing. GravityCam will also improve substantially the quality of weak shear studies of dark matter distribution in distant...

  8. Illness narratives in cancer: CAM and spiritual practices

    DEFF Research Database (Denmark)

    Ulrich, Anita; Evron, Lotte; Ostenfeld-Rosenthal, Ann

    2011-01-01

    be related to CAM. The analysis is based on empirical findings from a recent PhD project. During a two-year period first author followed 32 cancer patients, family, friends and alternative practitioners through interviews, telephone conversations, treatments and in focus groups. Results: As a general pattern......Objectives: In this paper,we investigate Danish cancer patients’ narratives on spiritual beliefs and practices and the relationship these practices may have to complementary and alternative medicine (CAM). Design: Narrative inquiry is used to uncover how spiritual beliefs and practices may......, religious and spiritual issues were not extensively unfolded in participants’ illness narratives. However, these issues were significantly elaborated on in narratives by four female participants. Conclusion: We propose that for some cancer patients CAM may function, not only or primarily as a treatment...

  9. Xi-CAM v1.2.3

    Energy Technology Data Exchange (ETDEWEB)

    2016-09-06

    Xi-CAM aims to provide a community driven platform for multimodal analysis in synchrotron science. The platform core provides a robust plugin infrastructure for extensibility, allowing continuing development to simply add further functionality. Current modules include tools for characterization with (GI)SAXS, Tomography, and XAS. This will continue to serve as a development base as algorithms for multimodal analysis develop. Seamless remote data access, visualization and analysis are key elements of Xi-CAM, and will become critical to synchrotron data infrastructure as expectations for future data volume and acquisition rates rise with continuously increasing throughputs. The highly interactive design elements of Xi-cam will similarly support a generation of users which depend on immediate data quality feedback during high-throughput or burst acquisition modes.

  10. CAM Modalities Can Stimulate Advances in Theoretical Biology.

    Science.gov (United States)

    Hankey, Alex

    2005-03-01

    Most complementary medicine is distinguished by not being supported by underlying theory accepted by Western science. However, for those who accept their validity, complementary and alternative medicine (CAM) modalities offer clues to understanding physiology and medicine more deeply. Ayurveda and vibrational medicine are stimulating new approaches to biological regulation. The new biophysics can be integrated to yield a single consistent theory, which may well underly much of CAM-a true 'physics of physick'. The resulting theory seems to be a new, fundamental theory of health and etiology. It suggests that many CAM approaches to health care are scientifically in advance of those based on current Western biology. Such theories may well constitute the next steps in our scientific understanding of biology itself. If successfully developed, these ideas could result in a major paradigm shift in both biology and medicine, which will benefit all interested parties-consumers, health professionals, scientists, institutions and governments. PMID:15841271

  11. Ways of improving photosynthesis by induced mutation

    International Nuclear Information System (INIS)

    Three ways of increasing photosynthetic efficiency in C3 plants by induced mutation are described. In the first procedure, using the crucifer Arabidopsis thaliana as a model organism, several single recessive nuclear mutations have been recovered in enzymes of the photorespiratory pathway. These mutations render photorespiration a conditionally lethal characteristic. The mutant strains are then used to select for second-site revertants which survive the lethal conditions. Such revertants would be unable to initiate the photorespiratory pathway, and therefore possess enhanced photosynthetic activity. In a second approach, designed to determine the feasibility of altering the two activities of ribulose bisphosphate carboxylase (Rubisco), the enzyme which regulates carbon flow between photosynthesis and photorespiration, uniparental mutants of Chlamydomonas reinhardii have been recovered which possess defective Rubisco. These mutants, lacking the ability to fix CO2, cannot survive phototrophically. Phototrophic revertants are then recovered and the Rubisco enzyme is examined. A search is being made for revertants with an increased carboxylation/oxygenation ratio, indicating increased photosynthetic efficiency. Finally, unicellular algae such as C. reinhardii are able to increase the in-vivo carboxylation efficiency of Rubisco by concentrating CO2 internally. To elucidate the nature of this CO2 concentrating system, and to determine whether such a system might be incorporated into higher plant species with C3 photosynthesis, induced mutants which are not capable of concentrating CO2 have been sought. Mutants with the expected phenotype, a high CO2 growth requirement, have been recovered and partially characterized. (author)

  12. Carbon dioxide fixation by artificial photosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Ibusuki, Takashi; Koike, Kazuhide; Ishitani, Osamu [National Inst. for Resources and Environment, AIST, MITI, Tsukuba, Ibaraki (Japan)

    1993-12-31

    Green plants can absorb atmospheric CO{sub 2} and transform it to sugars, carbohydrates through their photosynthetic systems, but they become the source of CO{sub 2} when they are dead. This is the reason why artificial leaves which can be alive forever should be developed to meet with global warming due to the increase of CO{sub 2} concentration. The goal of artificial photosynthesis is not to construct the same system as the photosynthetic one, but to mimic the ability of green plants to utilize solar energy to make high energy chemicals. Needless to say, the artificial photosynthetic system is desired to be as simple as possible and to be as efficient as possible. From the knowledge on photosynthesis and the results of previous investigations, the critical components of artificial photosynthetic system are understood as follows: (1) light harvesting chromophore, (2) a center for electron transfer and charge separation, (3) catalytic sites for converting small molecules like water and CO{sub 2} (mutilelectron reactions) which are schematically described.

  13. THE PATH OF CARBON IN PHOTOSYNTHESIS

    Energy Technology Data Exchange (ETDEWEB)

    Bassham, J.A.; Calvin, Melvin

    1960-10-01

    Biosynthesis begins with photosynthesis. Green plants and other photosynthetic organisms use the energy of absorbed visible light to make organic compounds from inorganic compounds. These organic compounds are the starting point for all other biosynthetic pathways. The products of photosynthesis provide not only the substrate material but also chemical energy for all subsequent biosynthesis. For example, nonphotosynthetic organisms making fats from sugars would first break down the sugars to smaller organic molecules. Some of the smaller molecules might be oxidized with O{sub 2} to CO{sub 2} and water. These reactions are accompanied by a release of chemical energy because O{sub 2} and sugar have a high chemical potential energy towards conversion to CO{sub 2} and H{sub 2}O. In a biochemical system only part of this energy would be released as heat. The heat would be used to bring about the conversion of certain enzymic cofactors to their more energetic forms. These cofactors would then enter into specific enzymic reactions in such a way as to supply energy to drive reactions in the direction of fat synthesis. Fats would be formed from the small organic molecules resulting from the breakdown of sugars. Thus sugar, a photosynthetic product, can supply both the energy and the material for the biosynthesis of fats.

  14. The Path of Carbon in Photosynthesis

    Science.gov (United States)

    Bassham, J. A.; Calvin, Melvin

    1960-10-01

    Biosynthesis begins with photosynthesis. Green plants and other photosynthetic organisms use the energy of absorbed visible light to make organic compounds from inorganic compounds. These organic compounds are the starting point for all other biosynthetic pathways. The products of photosynthesis provide not only the substrate material but also chemical energy for all subsequent biosynthesis. For example, nonphotosynthetic organisms making fats from sugars would first break down the sugars to smaller organic molecules. Some of the smaller molecules might be oxidized with O{sub 2} to CO{sub 2} and water. These reactions are accompanied by a release of chemical energy because O{sub 2} and sugar have a high chemical potential energy towards conversion to CO{sub 2} and H{sub 2}O. In a biochemical system only part of this energy would be released as heat. The heat would be used to bring about the conversion of certain enzymic cofactors to their more energetic forms. These cofactors would then enter into specific enzymic reactions in such a way as to supply energy to drive reactions in the direction of fat synthesis. Fats would be formed from the small organic molecules resulting from the breakdown of sugars. Thus sugar, a photosynthetic product, can supply both the energy and the material for the biosynthesis of fats.

  15. The regulatory interplay between photorespiration and photosynthesis.

    Science.gov (United States)

    Timm, Stefan; Florian, Alexandra; Fernie, Alisdair R; Bauwe, Hermann

    2016-05-01

    The Calvin-Benson cycle and the photorespiratory pathway form the photosynthetic-photorespiratory supercycle that is responsible for nearly all biological CO2 fixation on Earth. In essence, supplementation with the photorespiratory pathway is necessary because the CO2-fixing enzyme of the Calvin-Benson cycle, ribulose 1,5-bisphosphate carboxylase (Rubisco), catalyses several side reactions including the oxygenation of ribulose 1,5-bisphosphate, which produces the noxious metabolite phosphoglycolate. The photorespiratory pathway recycles the phosphoglycolate to 3-phosphoglycerate and in this way allows the Calvin-Benson cycle to operate in the presence of molecular oxygen generated by oxygenic photosynthesis. While the carbon flow through the individual and combined subprocesses is well known, information on their regulatory interaction is very limited. Regulatory feedback from the photorespiratory pathway to the Calvin-Benson cycle can be presumed from numerous inhibitor experiments and was demonstrated in recent studies with transgenic plants. This complexity illustrates that we are not yet ready to rationally engineer photosynthesis by altering photorespiration since despite massive understanding of the core photorespiratory pathway our understanding of its interaction with other pathways and processes remains fragmentary. PMID:26969745

  16. Growth irradiance effects on photosynthesis and growth in two co-occurring shade-tolerant neotropical perennials of contrasting photosynthetic pathways.

    Science.gov (United States)

    Skillman, John B; Garcia, Milton; Virgo, Aurelio; Winter, Klaus

    2005-11-01

    Dieffenbachia longispatha (C3) and Aechmea magdalenae (Crassulacean acid metabolism, CAM) are syntopic, neotropical forest perennials in central Panama that are restricted to shaded habitats. This is of particular interest for A. magdalenae because, like other understory CAM bromeliad species, it appears functionally and structurally to be better suited to life in full sun. Growth irradiance (GI) effects on photosynthesis and growth in both species were explored in the context of sun/shade trade-off concepts largely derived from studies of C3 plants. Potted plants were grown outdoors in 1, 55, and 100% full sun for 5 mo under well-watered conditions. While both species grew faster in high compared to low light, maximum relative growth rates (RGR) in full sun were still extremely slow with A. magdalenae showing a RGR approximately half that of D. longispatha. Photosynthetic capacity increased with GI in D. longispatha but not in A. magdalenae. Aechmea magdalenae responded to GI with shifts in the activity of the different CAM phases. Both species were photoinhibited in full sun, but more so in A. magdalenae. Despite possessing many traits considered adaptive in high light, these results suggest that A. magdalenae is unlikely to attain sufficient growth rates to thrive in productive, high-light habitats. PMID:21646098

  17. Concerns of Hydrothermal Degradation in CAD/CAM Zirconia

    OpenAIRE

    Kim, J.-W.; Covel, N.S.; Guess, P.C.; Rekow, E.D.; Zhang, Y.

    2010-01-01

    Zirconia-based restorations are widely used in prosthetic dentistry; however, their susceptibility to hydrothermal degradation remains elusive. We hypothesized that CAD/CAM machining and subsequent surface treatments, i.e., grinding and/or grit-blasting, have marked effects on the hydrothermal degradation behavior of Y-TZP. CAD/CAM-machined Y-TZP plates (0.5 mm thick), both with and without subsequent grinding with various grit sizes or grit-blasting with airborne alumina particles, were subj...

  18. Update on CAD/CAM activities at Sandia Laboratories

    Energy Technology Data Exchange (ETDEWEB)

    Oliver, D.A.

    1977-09-01

    Development of systems for Computer-Aided Design and Computer-Aided Manufacturing (CAD/CAM) has been underway at Sandia Laboratories for several years. These include systems for circuit design and analysis, systems for design and fabrication of printed circuit boards and hybrid microcircuits, and systems for mechanical applications, such as mass properties calculations and stress analysis. CAD/CAM operations have proved successful for electronic applications. Current emphasis is on development of mechanical support software, and with putting into production a machine-aided design and definition system (MADDS) utilizing Applicon Graphics Systems (AGS). 14 figures. (RWR)

  19. CAD/CAM system based upon the IAPX 432

    Energy Technology Data Exchange (ETDEWEB)

    Criscione, D.J.

    1983-01-01

    The Intel Corporation has developed a 32 bit microprocessor which provides hardware support for object oriented applications, accommodates concurrent processing in a manner invisible to the user, and allows easy interfacing to peripherals. These features, along with numerous others that have never been offered before in a microprocessor, makes the IAPX 432 an attractive base for CAD/CAM. The author outlines one possible implementation of a CAD/CAM system with the 432 at its heart. The advantages offered by the 432 are weighed against its limitations. 5 references.

  20. CAD/CAM: improved design quality, increased productivity

    Energy Technology Data Exchange (ETDEWEB)

    Evans, D. E.; England, J.

    1980-01-01

    Maintaining productivity levels while assuring the quality of engineering products grows increasingly more difficult and costly for industries such as the energy industry which are heavily committed to product design. The man/machine interface made possible through the development of computer-aided design/computer-aided manufacturing (CAD/CAM) technology can be applied to the design process as a tool for increased control to assure the quality of the final engineering product. The quality-control aspects of CAD/CAM technology are addressed in this presentation.

  1. CAD/CAM in the Brazilian aeronautical industry

    Science.gov (United States)

    Lampi, L. H.; Embraer, S. A.

    Features, applications and progress in the usage of CAD/CAM since 1980 by an aircraft manufacturer in Brazil are described. The system comprises 34 graphics work stations dedicated to structural design, lofting, electrical cable routing, finite element modeling and quality control. Standardized work methods have been devised to enhance productivity. Programs have been defined for finite element stress analysis and generating wiring diagrams. The computerized design capabilities have increased productivity for hole boring accuracy through work on digitized controllers. Psychological testing has been initiated to identify users who can adapt more easily to CAD/CAM utilization.

  2. Marginal Integrity of CAD/CAM Fixed Partial Dentures

    OpenAIRE

    Rosentritt, Martin; Behr, Michael; Kolbeck, Carola; Handel, Gerhard

    2007-01-01

    Objectives Computer-aided design (CAD) and manufacturing (CAM) allows the milling of high strength zirconia fixed partial dentures (FPD), however bonding to an inert ZrO2 ceramic surface may effect the marginal integrity of the FPDs. The aim of this investigation was to evaluate the marginal adaptation of zirconia FPDs at the interfaces between zirconia, cement, and tooth. Methods 32 3-unit FPDs were fabricated of the CAD/CAM Y-TZP zirconia (Lava, 3M Espe, Germany) according to the manufactur...

  3. Special Section: Complementary and Alternative Medicine (CAM):Quiz on Complementary and Alternative Medicine

    Science.gov (United States)

    ... Special Section CAM Quiz on Complementary and Alternative Medicine Past Issues / Winter 2009 Table of Contents For ... low back pain. True False Complementary and alternative medicine (CAM) includes: Meditation Chiropractic Use of natural products, ...

  4. CAM visual stimulation with conventional method of occlusion treatment in amblyopia: a randomized clinical trial

    Directory of Open Access Journals (Sweden)

    Ali Reza Jafari

    2014-04-01

    Conclusion: Using of CAM visual stimulation along with conventional occlusion will further improve visual acuity and stereopsis in amblyopic children. These findings recommended the CAM visual stimulation as an accompanying and complementary method in amblyopia treatment.

  5. Exploring Photosynthesis and Plant Stress Using Inexpensive Chlorophyll Fluorometers

    Science.gov (United States)

    Cessna, Stephen; Demmig-Adams, Barbara; Adams, William W., III

    2010-01-01

    Mastering the concept of photosynthesis is of critical importance to learning plant physiology and its applications, but seems to be one of the more challenging concepts in biology. This teaching challenge is no doubt compounded by the complexity by which plants alter photosynthesis in different environments. Here we suggest the use of chlorophyll…

  6. Modulated Chlorophyll "a" Fluorescence: A Tool for Teaching Photosynthesis

    Science.gov (United States)

    Marques da Silva, Jorge; Bernardes da Silva, Anabela; Padua, Mario

    2007-01-01

    "In vivo" chlorophyll "a" fluorescence is a key technique in photosynthesis research. The recent release of a low cost, commercial, modulated fluorometer enables this powerful technology to be used in education. Modulated chlorophyll a fluorescence measurement "in vivo" is here proposed as a tool to demonstrate basic photosynthesis phenomena to…

  7. A model for chlorophyll fluorescence and photosynthesis at leaf scale

    NARCIS (Netherlands)

    Tol, van der C.; Verhoef, W.; Rosema, A.

    2009-01-01

    This paper presents a leaf biochemical model for steady-state chlorophyll fluorescence and photosynthesis of C3 and C4 vegetation. The model is a tool to study the relationship between passively measured steady-state chlorophyll fluorescence and actual photosynthesis, and its evolution during the da

  8. Chlorophyll Fluorescence Analysis of Cyanobacterial Photosynthesis and Acclimation

    OpenAIRE

    Campbell, Douglas; Hurry, Vaughan; Adrian K Clarke; Gustafsson, Petter; Öquist, Gunnar

    1998-01-01

    Cyanobacteria are ecologically important photosynthetic prokaryotes that also serve as popular model organisms for studies of photosynthesis and gene regulation. Both molecular and ecological studies of cyanobacteria benefit from real-time information on photosynthesis and acclimation. Monitoring in vivo chlorophyll fluorescence can provide noninvasive measures of photosynthetic physiology in a wide range of cyanobacteria and cyanolichens and requires only small samples. Cyanobacterial fluore...

  9. Secondary Students' Interpretations of Photosynthesis and Plant Nutrition.

    Science.gov (United States)

    Ozay, Esra; Oztas, Haydar

    2003-01-01

    Studies misconceptions held by grade 9 students (14-15-years old) in Turkey about photosynthesis and plant nutrition. Uses a questionnaire to test students' conceptions and reports conflicting and often incorrect ideas about photosynthesis, respiration, and energy flow in plants. Suggests that there are difficulties in changing students' prior…

  10. Modelling C₃ photosynthesis from the chloroplast to the ecosystem.

    Science.gov (United States)

    Bernacchi, Carl J; Bagley, Justin E; Serbin, Shawn P; Ruiz-Vera, Ursula M; Rosenthal, David M; Vanloocke, Andy

    2013-09-01

    Globally, photosynthesis accounts for the largest flux of CO₂ from the atmosphere into ecosystems and is the driving process for terrestrial ecosystem function. The importance of accurate predictions of photosynthesis over a range of plant growth conditions led to the development of a C₃ photosynthesis model by Farquhar, von Caemmerer & Berry that has become increasingly important as society places greater pressures on vegetation. The photosynthesis model has played a major role in defining the path towards scientific understanding of photosynthetic carbon uptake and the role of photosynthesis on regulating the earth's climate and biogeochemical systems. In this review, we summarize the photosynthesis model, including its continued development and applications. We also review the implications these developments have on quantifying photosynthesis at a wide range of spatial and temporal scales, and discuss the model's role in determining photosynthetic responses to changes in environmental conditions. Finally, the review includes a discussion of the larger-scale modelling and remote-sensing applications that rely on the leaf photosynthesis model and are likely to open new scientific avenues to address the increasing challenges to plant productivity over the next century. PMID:23590343

  11. Exploring Undergraduates' Understanding of Photosynthesis Using Diagnostic Question Clusters

    Science.gov (United States)

    Parker, Joyce M.; Anderson, Charles W.; Heidemann, Merle; Merrill, John; Merritt, Brett; Richmond, Gail; Urban-Lurain, Mark

    2012-01-01

    We present a diagnostic question cluster (DQC) that assesses undergraduates' thinking about photosynthesis. This assessment tool is not designed to identify individual misconceptions. Rather, it is focused on students' abilities to apply basic concepts about photosynthesis by reasoning with a coordinated set of practices based on a few scientific…

  12. Photosynthesis sensitivity to climate change in land surface models

    Science.gov (United States)

    Manrique-Sunen, Andrea; Black, Emily; Verhoef, Anne; Balsamo, Gianpaolo

    2016-04-01

    Accurate representation of vegetation processes within land surface models is key to reproducing surface carbon, water and energy fluxes. Photosynthesis determines the amount of CO2 fixated by plants as well as the water lost in transpiration through the stomata. Photosynthesis is calculated in land surface models using empirical equations based on plant physiological research. It is assumed that CO2 assimilation is either CO2 -limited, radiation -limited ; and in some models export-limited (the speed at which the products of photosynthesis are used by the plant) . Increased levels of atmospheric CO2 concentration tend to enhance photosynthetic activity, but the effectiveness of this fertilization effect is regulated by environmental conditions and the limiting factor in the photosynthesis reaction. The photosynthesis schemes at the 'leaf level' used by land surface models JULES and CTESSEL have been evaluated against field photosynthesis observations. Also, the response of photosynthesis to radiation, atmospheric CO2 and temperature has been analysed for each model, as this is key to understanding the vegetation response that climate models using these schemes are able to reproduce. Particular emphasis is put on the limiting factor as conditions vary. It is found that while at present day CO2 concentrations export-limitation is only relevant at low temperatures, as CO2 levels rise it becomes an increasingly important restriction on photosynthesis.

  13. On the relation between phototaxis and photosynthesis in Rhodospirillum Rubrum

    NARCIS (Netherlands)

    Thomas, J.B.; Nijenhuis, L.E.

    1950-01-01

    The relation between phototaxis and photosynthesis in Rhodospirillum rubrum has been studied. The light intensity at which saturation is reached in photosynthesis proved to coincide with that at which the contrast sensitivity starts to decrease. Potassium cyanide, which preferably inhibits the Bla

  14. Single Roller-to-Cam Indexing Mechanisms Providing Two Maximized Dwells: Determination of Cam Pitch Profile for Optimal Designs

    Science.gov (United States)

    Tripathi, K. S.

    2015-04-01

    The view point of present research paper is concentrated on a part of a systematic scientific investigation of the mechanical possibilities of generating non-uniform full-rotational output motion with intermittent motion as the most important special case. The paper develops a geometrical construction of the cam pitch profile for optimal designs for single roller-to-cam indexing mechanism providing either two unequal maximum extent dwells with equal indexing angles (and unequal indexing periods) or two equal maximized dwells with unequal indexing angles (and equal indexing periods). Placement of the two dwells in the same half of the motion cycle gives very small periods; very high accelerations; and poor radius of curvature in the transition portion. Hence this paper considers optimal motion diagrams for the case of two dwells placed in different halves of the motion cycle and using the principle of kinematic inversion with intuitive conviction very tactically determines the cam pitch profile.

  15. Can the photosynthesis first step quantum mechanism be explained?

    CERN Document Server

    Sacilotti, Marco; Mota, Claudia C B O; Nunes, Frederico Dias; Gomes, Anderson S L

    2010-01-01

    Photosynthesis first step mechanism concerns the sunlight absorption and both negative and positive charges separation. Recent and important photosynthesis literature claims that this mechanism is quantum mechanics controlled, however without presenting qualitative or quantitative scientifically based mechanism. The present accepted and old-fashioned photosynthesis mechanism model suffers from few drawbacks and an important issue is the absence of driving force for negative and positive charges separation. This article presents a new qualitative model for this first step mechanism in natural catalytic systems such as photosynthesis in green leaves. The model uses a concept of semiconductor band gap engineering, such as the staggered energy band gap line-up in semiconductors. To explain the primary mechanism in natural photosynthesis the proposal is the following: incident light is absorbed inside the leaves causing charges separation. The only energetic configuration that allows charges separation under illum...

  16. CAD-CAM experiences at Bendix Kansas City: the user perspective

    Energy Technology Data Exchange (ETDEWEB)

    Mentesana, C.

    1983-04-01

    The Bendix Kansas City Division manufactures a variety of precision mechanical, electrical and electronic components and assemblies for the Department of Energy. CAD-CAM has been in use at Bendix for about two years. Development of CAD-CAM is the responsibility of the CAD-CAM Operations group. This group works with users, in-house computer professionals and vendors to provide CAD-CAM products and services.

  17. Thinking about the evolution of photosynthesis.

    Science.gov (United States)

    Olson, John M; Blankenship, Robert E

    2004-01-01

    Photosynthesis is an ancient process on Earth. Chemical evidence and recent fossil finds indicate that cyanobacteria existed 2.5-2.6 billion years (Ga) ago, and these were certainly preceded by a variety of forms of anoxygenic photosynthetic bacteria. Carbon isotope data suggest autotrophic carbon fixation was taking place at least a billion years earlier. However, the nature of the earliest photosynthetic organisms is not well understood. The major elements of the photosynthetic apparatus are the reaction centers, antenna complexes, electron transfer complexes and carbon fixation machinery. These parts almost certainly have not had the same evolutionary history in all organisms, so that the photosynthetic apparatus is best viewed as a mosaic made up of a number of substructures each with its own unique evolutionary history. There are two schools of thought concerning the origin of reaction centers and photosynthesis. One school pictures the evolution of reaction centers beginning in the prebiotic phase while the other school sees reaction centers evolving later from cytochrome b in bacteria. Two models have been put forth for the subsequent evolution of reaction centers in proteobacteria, green filamentous (non-sulfur) bacteria, cyanobacteria, heliobacteria and green sulfur bacteria. In the selective loss model the most recent common ancestor of all subsequent photosynthetic systems is postulated to have contained both RC1 and RC2. The evolution of reaction centers in proteobacteria and green filamentous bacteria resulted from the loss of RC1, while the evolution of reaction centers in heliobacteria and green sulfur bacteria resulted from the loss of RC2. Both RC1 and RC2 were retained in the cyanobacteria. In the fusion model the most recent common ancestor is postulated to have given rise to two lines, one containing RC1 and the other containing RC2. The RC1 line gave rise to the reaction centers of heliobacteria and green sulfur bacteria, and the RC2 line led

  18. The detection of EpCAM+ and EpCAM– circulating tumor cells

    NARCIS (Netherlands)

    Wit, de Sanne; Dalum, van Guus; Lenferink, Aufried; Tibbe, Arjan G.J.; Hilterman, T. Jeroen N.; Groen, Harry J.M.; Rijn, van Cees J.M.; Terstappen, Leon W.M.M.

    2015-01-01

    EpCAM expressing circulating tumor cells, detected by CellSearch, are predictive of short survival in several cancers and may serve as a liquid biopsy to guide therapy. Here we investigate the presence of EpCAM+ CTC detected by CellSearch and EpCAM– CTC discarded by CellSearch, after EpCAM based enr

  19. The role of complementary and alternative medicine (CAM) in Germany - a focus group study of GPs.

    NARCIS (Netherlands)

    Joos, S.; Musselmann, B.; Miksch, A.; Rosemann, T.J.; Szecsenyi, J.

    2008-01-01

    BACKGROUND: There has been a marked increase in the use of complementary and alternative medicine (CAM) in recent years worldwide. In Germany, apart from 'Heilpraktiker' (= state-licensed, non-medical CAM practitioners), some general practitioners (GPs) provide CAM in their practices. This paper aim

  20. The development of cam-type deformity in adolescent and young male soccer players

    NARCIS (Netherlands)

    R. Agricola (Rintje); J.H.J.M. Bessems (Gert); A.Z. Ginai (Abida); M.P. Heijboer (Rien); R.A. van der Heijden (Rianne); J.A.N. Verhaar (Jan); H.H. Weinans (Harrie); J.H. Waarsing (Jan)

    2012-01-01

    textabstractBackground: Cam impingement is a well-recognized cause of hip pain and might cause osteoarthritis of the hip. Clinically, cam impingement is mostly observed in young, active male patients, but only a few studies have focused on the manifestation of cam-type deformities during skeletal de

  1. CamOn: A Real-Time Autonomous Camera Control System

    DEFF Research Database (Denmark)

    Burelli, Paolo; Jhala, Arnav Harish

    2009-01-01

    This demonstration presents CamOn, an autonomous cam- era control system for real-time 3D games. CamOn employs multiple Artificial Potential Fields (APFs), a robot motion planning technique, to control both the location and orienta- tion of the camera. Scene geometry from the 3D environment...

  2. Computer-aided engineering: the step beyond CAD/CAM

    Energy Technology Data Exchange (ETDEWEB)

    Hatfield, L.; Trost, S.R.; O' Brien, D.W.; Pomernacki, C.L.

    1981-11-06

    At Lawrence Livermore National Laboratory, the need for increased engineering productivity, coupled with increasingly difficult engineering problems, presents a significant challenge. Advances in computer technology coupled with successful CAD/CAM experiences suggest that computer-aided engineering (CAE) will help meet this challenge. Requirements for a CAE system are developed, a CAE system plan is outlined, and some remaining problem areas are discussed.

  3. Making IGES work for CAD/CAM data exchange

    Energy Technology Data Exchange (ETDEWEB)

    Ames, A.L.; Fletcher, S.K.

    1985-01-01

    This report outlines Sandia National Laboratories effort to integrate the CAE/CAD/CAM capabilities of three laboratories and six production plants in the DOE weapons complex with the Initial Graphics Exchange Specifications (IGES). The problems with IGES are addressed and solutions are explained. The implementation of the IGES concept is also outlined.

  4. Automated regression testing of CAD/CAM systems

    Energy Technology Data Exchange (ETDEWEB)

    Burd, W.C.

    1988-01-01

    A description of automated software quality assurance techniques is presented. These techniques detect regression in the ''unchanged'' functions of CAD/CAM software during new updates from a vendor. Interfaces for the test mechanisms, methods for automatic results analysis, test management requirements, and experience gained from a prototype automatic regression test system are included. 7 figs.

  5. Schools (Students) Exchanging CAD/CAM Files over the Internet.

    Science.gov (United States)

    Mahoney, Gary S.; Smallwood, James E.

    This document discusses how students and schools can benefit from exchanging computer-aided design/computer-aided manufacturing (CAD/CAM) files over the Internet, explains how files are exchanged, and examines the problem of selected hardware/software incompatibility. Key terms associated with information search services are defined, and several…

  6. An Updated and Upgraded L1CAM Mutation Database

    NARCIS (Netherlands)

    Vos, Yvonne J.; Hofstra, Robert M. W.

    2010-01-01

    The L1 syndrome is an X-linked recessive disease caused by mutations in the L1CAM gene. To date more than 200 different mutations have been reported, scattered over the entire gene, about 35% being missense mutations. Although it is tempting to consider these missense mutations as being disease-caus

  7. Potential worker risk as a function of CAM airflow rate

    Energy Technology Data Exchange (ETDEWEB)

    Whicker, J.J.

    1994-03-21

    The goal of the continuous air monitor (CAM) system at the Los Alamos National Laboratory`s Plutonium Facility (PF-4) is to have a flow rate of 1 cubic feet per minute (cfm) drawn through the CAMs. However, design limitations in the house vacuum result in many CAMs having less than 1 cfm being drawn through them. Reduced flow rates through CAMs present a compromise in worker protection. Laboratory Health and Safety personnel and DOE officials established a flow rate of 0.5 cfm or less as operationally unacceptable. This report quantitatively estimated the difference in risk to workers from a reduced flow rate of 0.5 cfm relative to the risk inherent with a flow rate of 1 cfm. I calculated risk in terms of Committed Effective Dose Equivalent (CEDE) and used units of rem. Estimates for the increase in risk for 0.5 cfm compared to 1 cfm ranged from 0.32 rem to 3.3 rem. The difference in the minimum alarm concentration between 0.5 cfm and I cfm was also compared and was estimated to range from 0.4 rem to 4 rem.

  8. Strength influencing variables on CAD/CAM zirconia frameworks

    NARCIS (Netherlands)

    H. Wang; M.N.M. Abou Shelib; A.J. Feilzer

    2008-01-01

    Purpose. Many studies in the dental literature look at the effect of different surface treatment methods on the flexure strength of zirconia where polished zirconia has been used as control. However, zirconia is subjected to different types of surface damage as a result of the CAD/CAM milling proced

  9. Solar fuels production by artificial photosynthesis

    International Nuclear Information System (INIS)

    A practical method to use sunlight to generate storable chemical energy could dramatically change the landscape of global energy generation. One of the fundamental requirements of such an “artificial photosynthesis” scheme is a light capture and conversion approach capable of generating the required chemical potentials (e.g. >1.23 V for splitting water into H2 and O2). An approach based on inorganic light absorbers coupled directly to oxidation and reduction catalysts is being developed in the Joint Center for Artificial Photosynthesis (JCAP). P-type III-V semiconductors with a high surface area can be used as high current density photocathodes. The longevity under operation of these photocathodes can be improved by the use of conformal metal oxides deposited by atomic layer deposition

  10. Chloroplast transformation for engineering of photosynthesis.

    Science.gov (United States)

    Hanson, Maureen R; Gray, Benjamin N; Ahner, Beth A

    2013-01-01

    Many efforts are underway to engineer improvements in photosynthesis to meet the challenges of increasing demands for food and fuel in rapidly changing environmental conditions. Various transgenes have been introduced into either the nuclear or plastid genomes in attempts to increase photosynthetic efficiency. We examine the current knowledge of the critical features that affect levels of expression of plastid transgenes and protein accumulation in transplastomic plants, such as promoters, 5' and 3' untranslated regions, RNA-processing sites, translation signals and amino acid sequences that affect protein turnover. We review the prior attempts to manipulate the properties of ribulose-1,5-bisphosphate carboxylase oxygenase (Rubisco) through plastid transformation. We illustrate how plastid operons could be created for expression of the multiple genes needed to introduce new pathways or enzymes to enhance photosynthetic rates or reduce photorespiration. We describe here the past accomplishments and future prospects for manipulating plant enzymes and pathways to enhance carbon assimilation through plastid transformation. PMID:23162121

  11. ENERGY RECEPTION AND TRANSFER IN PHOTOSYNTHESIS

    Energy Technology Data Exchange (ETDEWEB)

    Calvin, Melvin

    1958-09-23

    The basic information about the path of carbon in photosynthesis is reviewed together with the methods that were used to discover it. This has led to the knowledge of what is required of the photochemical reaction in the form of chemical species. Attention is then directed to the structure of the photochemical apparatus itself insofar as it is viewable by electron microscopy, and some principoles of ordered structure are devised for the types of molecules to be found in the chloroplasts. From the combination of these, a structure for the grana lamella is suggested and a mode of function proposed. Experimental test for this mode of function is underway; one method is to examine photoproduced unpaired electrons. This is discussed.

  12. Measurements of photosynthesis and respiration in plants.

    Science.gov (United States)

    Hunt, Stephen

    2003-03-01

    Methods for measuring the rates of photosynthesis and respiration in plants are reviewed. Closed systems that involve manometric techniques, 14CO2 fixation, O2 electrodes and other methods for measuring dissolved and gas phase O2 are described. These methods typically provide time-integrated rate measurements, and limitations to their use are discussed. Open gas exchange systems that use infra-red CO2 gas analysers and differential O2 analysers for measuring instantaneous rates of CO2 and O2 exchange are described. Important features of the analysers, design features of gas exchange systems, and sources of potential error are considered. The analysis of chlorophyll fluorescence parameters for estimating the quantum yield for O2 evolution and CO2 fixation is described in relation to new fluorescence imaging systems for large scale screening of photosynthetic phenotypes, and the microimaging of individual chloroplasts. PMID:12654031

  13. Functional quantum biology in photosynthesis and magnetoreception

    CERN Document Server

    Lambert, Neill; Cheng, Yuan-Chung; Li, Che-Ming; Chen, Guang-Yin; Nori, Franco

    2012-01-01

    Is there a functional role for quantum mechanics or coherent quantum effects in biological processes? While this question is as old as quantum theory, only recently have measurements on biological systems on ultra-fast time-scales shed light on a possible answer. In this review we give an overview of the two main candidates for biological systems which may harness such functional quantum effects: photosynthesis and magnetoreception. We discuss some of the latest evidence both for and against room temperature quantum coherence, and consider whether there is truly a functional role for coherence in these biological mechanisms. Finally, we give a brief overview of some more speculative examples of functional quantum biology including the sense of smell, long-range quantum tunneling in proteins, biological photoreceptors, and the flow of ions across a cell membrane.

  14. Does coherence enhance transport in photosynthesis?

    CERN Document Server

    Kassal, Ivan; Rahimi-Keshari, Saleh

    2012-01-01

    Recent observations of coherence in photosynthetic complexes have led to the question of whether quantum effects can occur in vivo, not under femtosecond laser pulses but in incoherent sunlight and at steady state, and, if so, whether the coherence explains the high exciton transfer efficiency. We distinguish several types of coherence and show that although some photosynthetic pathways are partially coherent processes, photosynthesis in nature proceeds through stationary states. This distinction allows us to rule out several mechanisms of transport enhancement in sunlight. In particular, although they are crucial for understanding exciton transport, neither wavelike motion nor microscopic coherence, on their own, enhance the efficiency. By contrast, two partially coherent mechanisms---ENAQT and supertransfer---can enhance transport even in sunlight and thus constitute motifs for the optimisation of artificial sunlight harvesting. Finally, we clarify the importance of ultrafast spectroscopy in understanding i...

  15. The many meanings of gross photosynthesis and their implication for photosynthesis research from leaf to globe

    OpenAIRE

    Wohlfahrt, Georg; Gu, Lianhong

    2015-01-01

    (1)  Gross photosynthesis is a key term in plant biology and carbon cycle science, however has been used with different meanings by different communities (2)  We review the history of this term and associated concepts to clarify the terminology and make recommendations about a consistent use of terms in accordance with photosynthetic theory. (3)  We show that a widely used eddy covariance CO2 flux partitioning approach yields estimates which are quantitatively closer to the definition of true...

  16. Anoxygenic Photosynthesis Controls Oxygenic Photosynthesis in a Cyanobacterium from a Sulfidic Spring

    OpenAIRE

    Klatt, Judith M.; Al-Najjar, Mohammad A. A.; Yilmaz, Pelin; Lavik, Gaute; Beer, Dirk de; Polerecky, Lubos

    2015-01-01

    Before the Earth's complete oxygenation (0.58 to 0.55 billion years [Ga] ago), the photic zone of the Proterozoic oceans was probably redox stratified, with a slightly aerobic, nutrient-limited upper layer above a light-limited layer that tended toward euxinia. In such oceans, cyanobacteria capable of both oxygenic and sulfide-driven anoxygenic photosynthesis played a fundamental role in the global carbon, oxygen, and sulfur cycle. We have isolated a cyanobacterium, Pseudanabaena strain FS39,...

  17. An approach towards fully integration of CAD and CAM technologies

    Directory of Open Access Journals (Sweden)

    M. Tolouei-Rad

    2006-08-01

    Full Text Available Purpose: An integrated CAD/CAM system for milling operations has been developed which helps designers tosolve machining problems at the design stage.Design/methodology/approach: A methodology has been employed which provides all necessary informationfor machining products automatically. Use of these system results in reduced machining leadtimes and costthrough designing machinable components; using available cutting tools; improving machining efficiency. Thesystem is menu driven with a user friendly interface.Findings: Different components for developing such a system have been identified and various problems thatarose in the development of this system have been dealt with The system developed leads to an adequate basisfor fully integration of CAD and CAM technologies in one system. It allows simultaneous generation of allinformation required to satisfy machining requirements of the design such as its machinability and availabilityof the required tooling resources.Research limitations/implications: Different components required for developing such systems have beenidentified and various problems that arose in the development of these systems have been dealt with, leadingto an adequate basis for complete integration of CAD and CAM technologies. Although much of the workdescribed here goes beyond the scope of published literature, however, it should be noted that the systemdeveloped couldn’t be considered as a complete solution to the CAD/CAM integration problem. Further workrequires including other manufacturing activities that are considered in concurrent engineering concept. In thisdirection, further integration of the system developed with systems such as MRP, MRP II and assembly sequenceplanning packages are highly desirable.Originality/value: CAD/CAM integration is regarded as a solution for bridging the gap between design andmanufacturing, one of the ultimate goals for concurrent engineering. Since the advent of CAD and CAMnumerous

  18. Photosynthesis and fish production in culture ponds

    Energy Technology Data Exchange (ETDEWEB)

    Szyper, J.P.

    1995-12-31

    The widely-cultured Nile tilapia, Oreochromis niloticus, has been the major species used in standardized experiments by the Pond Dynamics/Aquaculture Collaborative Research Support Program (PD/ACRSP). Yields of Nile Tilapia from fertilized, unfed ponds have served as a bioassay for effectiveness of pond management protocols developed during worldwide tropical experiments. Yield rates near 10 T/ha/y can be achieved without feed inputs in ponds which maintain high standing stocks of phytoplankton and exhibit high rates near 10 T/ha/y can be achieved without feed inputs in ponds which maintain high standing stocks of phytoplankton and exhibit high rates of primary production. Fish production is related to daytime net photosynthetic production, but it is not clear whether production of food materials or oxygen is the more direct influence. Excessively high standing stocks of phytoplankton are not the best net producers, and increase and risk of nighttime oxygen depletion. Fish readily grow to individual sizes of 200-300 g/fish in fertilized ponds, which is sufficient market size in many locations. Supplemental feeding of caged or free-ranging fish greatly accelerates growth beyond 300 g and potentiates high areal yields; the PD/A CRSP has also developed efficient feeding regimes and shown that supplemental feeding need not begin before fish reach 200 g weight. High standing stocks of phytoplankton and high photosynthetic rates in eutrophic ponds make study of photosynthesis possible without radioisotopes. Such ponds also exhibit complete extinction of incident solar radiation within shallow depths, and vertical temperature structure resembling that of deeper bodies of water. These characteristics make ponds useful as microcosms for study of some aspects of photosynthesis in natural waters.

  19. CAMS newly detected meteor showers and the sporadic background

    Science.gov (United States)

    Jenniskens, P.; Nénon, Q.; Gural, P. S.; Albers, J.; Haberman, B.; Johnson, B.; Morales, R.; Grigsby, B. J.; Samuels, D.; Johannink, C.

    2016-03-01

    The Cameras for Allsky Meteor Surveillance (CAMS) video-based meteoroid orbit survey adds 60 newly identified showers to the IAU Working List of Meteor Showers (numbers 427, 445-446, 506-507, and part of 643-750). 28 of these are also detected in the independent SonotaCo survey. In total, 230 meteor showers and shower components are identified in CAMS data, 177 of which are detected in at least two independent surveys. From the power-law size frequency distribution of detected showers, we extrapolate that 36% of all CAMS-observed meteors originated from ∼700 showers above the N = 1 per 110,000 shower limit. 71% of mass falling to Earth from streams arrives on Jupiter-family type orbits. The transient Geminids account for another 15%. All meteoroids not assigned to streams form a sporadic background with highest detected numbers from the apex source, but with 98% of mass falling in from the antihelion source. Even at large ∼7-mm sizes, a Poynting-Robertson drag evolved population is detected, which implies that the Grün et al. collisional lifetimes at these sizes are underestimated by about a factor of 10. While these large grains survive collisions, many fade on a 104-y timescale, possibly because they disintegrate into smaller particles by processes other than collisions, leaving a more resilient population to evolve. The meteors assigned to the various showers are identified in the CAMS Meteoroid Orbit Database 2.0 submitted to the IAU Meteor Data Center, and can be accessed also at cams.seti.org" xlink:type="simple"

  20. Optimising the cam profile of an electronic unit pump for a heavy-duty diesel engine

    International Nuclear Information System (INIS)

    For a fuel system with a tangent cam or a constant-velocity cam, the peak injection pressure continues to rise as the injection duration increases, but overly high peak pressures induce mechanical loads and wear, limiting the maximum engine speed and injection quantity. To improve the performance of an EUP (Electronic Unit Pump) fuel system for heavy-duty diesel engines, this work proposes a new pump cam, namely the constant-pressure cam. It helps the EUP run at a higher speed and deliver larger fuel quantities while maintaining a constant peak injection pressure, which improves the power of the heavy-duty diesel engine. A model based on the EUP was built to determine the three constraints for optimising the constant-pressure cam: 1) the pump pressure should equal the nozzle pressure; 2) the cam speed should decrease with the increase in the injection duration; and 3) the cam acceleration gradient should be zero. An EUP system was tested with the tangent cam and the optimised cam under different conditions. The experimental results show that the EUP system with the optimised cam delivers more injection quantity and runs at higher engine speeds while maintaining the same peak pressure as the tangent cam. - Highlights: • We propose a constant-pressure cam to improve the power of heavy-duty diesel engine. • We deduce three constraints for the CP (constant-peak pressure) cam based on a model. • The EUP system with the new cam works well under higher engine speed. • The peak pressure of the constant-pressure cam fuel system maintains high

  1. Abnormal placental development and early embryonic lethality in EpCAM-null mice.

    Directory of Open Access Journals (Sweden)

    Keisuke Nagao

    Full Text Available BACKGROUND: EpCAM (CD326 is encoded by the tacstd1 gene and expressed by a variety of normal and malignant epithelial cells and some leukocytes. Results of previous in vitro experiments suggested that EpCAM is an intercellular adhesion molecule. EpCAM has been extensively studied as a potential tumor marker and immunotherapy target, and more recent studies suggest that EpCAM expression may be characteristic of cancer stem cells. METHODOLOGY/PRINCIPAL FINDINGS: To gain insights into EpCAM function in vivo, we generated EpCAM -/- mice utilizing an embryonic stem cell line with a tacstd1 allele that had been disrupted. Gene trapping resulted in a protein comprised of the N-terminus of EpCAM encoded by 2 exons of the tacstd1 gene fused in frame to betageo. EpCAM +/- mice were viable and fertile and exhibited no obvious abnormalities. Examination of EpCAM +/- embryos revealed that betageo was expressed in several epithelial structures including developing ears (otocysts, eyes, branchial arches, gut, apical ectodermal ridges, lungs, pancreas, hair follicles and others. All EpCAM -/- mice died in utero by E12.5, and were small, developmentally delayed, and displayed prominent placental abnormalities. In developing placentas, EpCAM was expressed throughout the labyrinthine layer and by spongiotrophoblasts as well. Placentas of EpCAM -/- embryos were compact, with thin labyrinthine layers lacking prominent vascularity. Parietal trophoblast giant cells were also dramatically reduced in EpCAM -/- placentas. CONCLUSION: EpCAM was required for differentiation or survival of parietal trophoblast giant cells, normal development of the placental labyrinth and establishment of a competent maternal-fetal circulation. The findings in EpCAM-reporter mice suggest involvement of this molecule in development of vital organs including the gut, kidneys, pancreas, lungs, eyes, and limbs.

  2. CO2 and O2 Exchanges in the CAM Plant Ananas comosus (L.) Merr

    Science.gov (United States)

    Cote, François Xavier; Andre, Marcel; Folliot, Michel; Massimino, Daniel; Daguenet, Alain

    1989-01-01

    Photosynthesis and light O2-uptake of the aerial portion of the CAM plant Ananas comosus (L.) merr. were studied by CO2 and O2 gas exchange measurements. The amount of CO2 which was fixed during a complete day-night cycle was equal to the amount of total net O2 evolved. This finding justifies the assumption that in each time interval of the light period, the difference between the rates of net O2-evolution and of net light atmospheric CO2-uptake give the rates of malate-decarboxylation-dependent CO2 assimilation. Based upon this hypothesis, the following photosynthetic characteristics were observed: (a) From the onset of the light to midphase IV of CAM, the photosynthetic quotient (net O2 evolved/net CO2 fixed) was higher than 1. This indicates that malate-decarboxylation supplied CO2 for the photosynthetic carbon reduction cycle during this period. (b) In phase III and early phase IV, the rate of CO2 assimilation deduced from net O2-evolution was 3 times higher than the maximum rate of atmospheric CO2-fixation during phase IV. A conceivable explanation for this stimulation of photosynthesis is that the intracellular CO2-concentration was high because of malate decarboxylation. (c) During the final hours of the light period, the photosynthetic quotient decreased below 1. This may be the result of CO2-fixation by phosphoenolpyruvate-carboxylase activity and malate accumulation. Based upon this hypothesis, the gas exchange data indicates that at least 50% of the CO2 fixed during the last hour of the light period was stored as malate. Light O2-uptake determined with 18O2 showed two remarkable characteristics: from the onset of the light until midphase IV the rate of O2-uptake increased progressively; during the following part of the light period, the rate of O2-uptake was 3.5 times higher than the maximum rate of CO2-uptake. When malate decarboxylation was reduced or suppressed after a night in a CO2-free atmosphere or in continuous illumination, the rate of O2-uptake

  3. CAD/CAM-mathematical models and information processing. CAD/CAM-sugaku model to joho shori

    Energy Technology Data Exchange (ETDEWEB)

    Kimura, F. (The Univ. of Tokyo, Tokyo (Japan). Research center for advanced Science and Technology)

    1990-09-05

    Works concerning industrial product design and production design are comprehensive works and it is said that its technique has not been systematized and there are many aspects of relying on human creativity and experience in the past. On the other hand, technological theories are the works of analysis and have well been developed based upon scientific academic systems. In the field of designing, standardized design procedures, etc. have been enciphered and its computerized automation has been progressed, but in normal design works including new design to a certain extent, its design procedures cannot be made as mathematical models, consequently its automation is obliged to base on an information processing model. The models which can express comprehensively all technical information concerning products necessary for design and production of industrial products are called product models. In this article, product modelling is roughly explained and the features of numerical models in CAD/CAM (computer assisted automation of mechanical design and production) are discussed taking geometrical modelling as a subject for discussion. 5 refs., 4 figs.

  4. Trend of CAD/CAM system in steel structure. Kenchiku tekkotsu CAD/CAM system no genjo to tenbo

    Energy Technology Data Exchange (ETDEWEB)

    Matsuura, K.; Tayama, K.

    1994-06-01

    The present situation and the future trend of the CAD/CAM system in steel structure were explained. In Japan, the CAD/CAM system in steel structure was introduced in 1983 for responding to the shortage of operators, shortening the construction period, and cost reduction. The systems introduced by fabricators can be classified into two types, i.e., the single functional type and the consistent type. Most of the single functional type system employs personal computers as for the hardware. Though it can be easily operated, there is a certain limit to functionality and treatment capacity. The consistent type system can provide many information such as fabrication drawing, full size template, and management document, though it is expensive and complicated. When the function of the system is heightened, the system becomes complicated. The future trend was considered. The combination of CAD/CAM, NC machine, and welding robot is indispensable for the rationalization. The completion of software for making the three-dimensional data is expected, for it will make it possible to fabricate the steel structure promptly and accurately. The network linkage of different CAD/CAM systems will be also promoted. In the future, it will be developed into the computer-aided integrated production system (CIM). 1 ref., 6 figs.

  5. A methodological framework for evaluating the evidence for Complementary and Alternative Medicine (CAM) for cancer

    DEFF Research Database (Denmark)

    Zachariae, Robert; Johannesen, Helle

    2011-01-01

    In spite of lacking evidence for effects on cancer progression itself, an increasing number of cancer patients use various types of complementary and alternative medicine (CAM). There is disagreement between CAM practitioners, researchers and clinical oncologists, as to how evidence concerning...... effects of CAM can and should be produced, and how the existing evidence should be interpreted. This represents a considerable challenge for oncologists; both in terms of patient needs for an informed dialogue regarding CAM, and because some types of CAM may interact with standard treatments...

  6. ST Chamaeleontis and BP Coronae Australis: Two Southern Dwarf Novae Confirmed as Z Cam Stars

    CERN Document Server

    Simonsen, Mike; Hambsch, Franz-Josef; Stubbings, Rod

    2014-01-01

    Z Camelopardalis (Z Cam) stars are a subset of dwarf novae distinguished by the occurrence of standstills, periods of relative constant brightness one to one and a half magnitudes fainter than maximum brightness. As part of an ongoing observing campaign, the Z CamPaign, the authors focused attention on several Z Cam suspects in the southern hemisphere. Two stars, BP Coronae Australis and ST Chamaeleontis were found to exhibit standstill behavior in 2013, thus confirming them as Z Cam type systems. This adds two more bona fide members to the 19 confirmed Z Cams, bringing the total to 21.

  7. The detection of EpCAM+ and EpCAM– circulating tumor cells

    OpenAIRE

    Sanne de Wit; Guus van Dalum; Lenferink, Aufried T. M.; Arjan G. J. Tibbe; T. Jeroen N. Hiltermann; Groen, Harry J. M.; van Rijn, Cees J. M.; Terstappen, Leon W.M.M.

    2015-01-01

    EpCAM expressing circulating tumor cells, detected by CellSearch, are predictive of short survival in several cancers and may serve as a liquid biopsy to guide therapy. Here we investigate the presence of EpCAM(+) CTC detected by CellSearch and EpCAM(-) CTC discarded by CellSearch, after EpCAM based enrichment. EpCAM(-) CTC were identified by filtration and fluorescent labelling. This approach was validated using different cell lines spiked into blood and evaluated on blood samples of 27 meta...

  8. A qualitative study on the term CAM: is there a need to reinvent the wheel?

    Directory of Open Access Journals (Sweden)

    Gaboury Isabelle

    2012-08-01

    Full Text Available Abstract Background As complementary and alternative medicine (CAM has developed extensively, uncertainty about the appropriateness of the terms CAM and other CAM-related terms has grown both in the research and practice communities. Various terms and definitions have been proposed over the last three decades, highlighting how little agreement exits in the field. Contextual use of current terms and their respective definitions needs to be discussed and addressed. Methods Relying upon the results of a large international Delphi survey on the adequacy of the term CAM, a focus group of 13 international experts in the field of CAM was held. A forum was also set up for 28 international experts to discuss and refine proposed definitions of both CAM and integrative healthcare (IHC terms. Audio recordings of the meeting and forum discussion threads were analyzed using interpretive description. Results Multiple terms to describe the therapies, products, and disciplines often referred to as CAM, were considered. Even though participants generally agreed there is a lack of optimal definitions for popular CAM-related umbrella terms and that all terms that have so far been introduced are to some extent problematic, CAM and IHC remained the most popular and accepted terms by far. The names of the specific disciplines were also deemed adequate in certain contexts. Focus group participants clarified the context in which those three terms are appropriate. Existing and emergent definitions of both CAM and integrative healthcare terms were discussed. Conclusions CAM and other related terms could be used more effectively, provided they are used in the proper context. It appears difficult for the time being to reach a consensus on the definition of the term CAM due to the uncertainty of the positioning of CAM in the contemporary healthcare systems. While umbrella terms such as CAM and IHC are useful in the context of research, policy making and education, relevant

  9. JunoCam: Science and Outreach Opportunities with Juno

    Science.gov (United States)

    Hansen, C. J.; Orton, G. S.

    2015-12-01

    JunoCam is a visible imager on the Juno spacecraft en route to Jupiter. Although the primary role of the camera is for outreach, science objectives will be addressed too. JunoCam is a wide angle camera (58 deg field of view) with 4 color filters: red, green and blue (RGB) and methane at 889 nm. Juno's elliptical polar orbit will offer unique views of Jupiter's polar regions with a spatial scale of ~50 km/pixel. The polar vortex, polar cloud morphology, and winds will be investigated. RGB color mages of the aurora will be acquired. Stereo images and images taken with the methane filter will allow us to estimate cloudtop heights. Resolution exceeds that of Cassini about an hour from closest approach and at closest approach images will have a spatial scale of ~3 km/pixel. JunoCam is a push-frame imager on a rotating spacecraft. The use of time-delayed integration takes advantage of the spacecraft spin to build up signal. JunoCam will acquire limb-to-limb views of Jupiter during a spacecraft rotation, and has the possibility of acquiring images of the rings from in-between Jupiter and the inner edge of the rings. Galilean satellite views will be fairly distant but some images will be acquired. Small ring moons Metis and Adrastea will also be imaged. The theme of our outreach is "science in a fish bowl", with an invitation to the science community and the public to participate. Amateur astronomers will supply their ground-based images for planning, so that we can predict when prominent atmospheric features will be visible. With the aid of professional astronomers observing at infrared wavelengths, we'll predict when hot spots will be visible to JunoCam. Amateur image processing enthusiasts are prepared to create image products. Between the planning and products will be the decision-making on what images to take when and why. We invite our colleagues to propose science questions for JunoCam to address, and to be part of the participatory process of deciding how to use

  10. Oxygenic photosynthesis: translation to solar fuel technologies

    Directory of Open Access Journals (Sweden)

    Julian David Janna Olmos

    2014-12-01

    Full Text Available Mitigation of man-made climate change, rapid depletion of readily available fossil fuel reserves and facing the growing energy demand that faces mankind in the near future drive the rapid development of economically viable, renewable energy production technologies. It is very likely that greenhouse gas emissions will lead to the significant climate change over the next fifty years. World energy consumption has doubled over the last twenty-five years, and is expected to double again in the next quarter of the 21st century. Our biosphere is at the verge of a severe energy crisis that can no longer be overlooked. Solar radiation represents the most abundant source of clean, renewable energy that is readily available for conversion to solar fuels. Developing clean technologies that utilize practically inexhaustible solar energy that reaches our planet and convert it into the high energy density solar fuels provides an attractive solution to resolving the global energy crisis that mankind faces in the not too distant future. Nature’s oxygenic photosynthesis is the most fundamental process that has sustained life on Earth for more than 3.5 billion years through conversion of solar energy into energy of chemical bonds captured in biomass, food and fossil fuels. It is this process that has led to evolution of various forms of life as we know them today. Recent advances in imitating the natural process of photosynthesis by developing biohybrid and synthetic “artificial leaves” capable of solar energy conversion into clean fuels and other high value products, as well as advances in the mechanistic and structural aspects of the natural solar energy converters, photosystem I and photosystem II, allow to address the main challenges: how to maximize solar-to-fuel conversion efficiency, and most importantly: how to store the energy efficiently and use it without significant losses. Last but not least, the question of how to make the process of solar

  11. Hydrogen peroxide and the evolution of oxygenic photosynthesis

    Science.gov (United States)

    Mckay, C. P.; Hartman, H.

    1991-01-01

    Possible pathways for the evolution of oxygenic photosynthesis in the early reducing atmosphere of the earth are discussed. It is suggested that the abiotic production of atmospheric oxidants could have provided a mechanism by which locally oxidizing conditions were sustained within spatially confined habitats thus removing the available reductants and forcing photosynthetic organisms to utilize water (rather than ferrous or sulfide ions) as the electron donor. It is argued that atmospheric H2O2 played the key role in inducing oxygenic photosynthesis, because, as peroxide concentrations local environments increased, primitive organisms would not only be faced with a loss of a reductant, but would be also forced to develop a biochemical apparatus (such as catalase) that would protect them against the products of oxygenic photosynthesis. This scenario allows for the early evolution of oxygenic photosynthesis at the time when global conditions were still anaerobic.

  12. Effect of Bradyrhizobium photosynthesis on stem nodulation of Aeschynomene sensitiva

    OpenAIRE

    Giraud, Eric; Hannibal, Laure; Fardoux, Joel; Verméglio, Andre; Dreyfus, Bernard

    2000-01-01

    Some leguminous species of the genus #Aeschynomene$ are specifically stem-nodulated by photosynthetic bradyrhizobia. To study the effect of bacterial photosynthesis during symbiosis, we generated a photosynthesis-negative mutant of the #Bradyrhizobium$ sp. strain ORS278 symbiont of #Aeschynomene sensitiva$. The presence of a functional photosynthetic unit in bacterioids and the high expression of the photosynthetic genes observed in stem nodules demonstrate that the bacteria are photosyntheti...

  13. Oxygen requirement and inhibition of C4 photosynthesis

    OpenAIRE

    Maroco, João; Ku, Maurice S. B.; Peter J. Lea; Dever, Louisa V.; Leegood, Richard C.; Furbank, Robert T.; Edwards, Gerald E.

    1998-01-01

    The basis for O2 sensitivity of C4 photosynthesis was evaluated using a C4-cycle-limited mutant of Amaranthus edulis (a phosphoenolpyruvate carboxylase-deficient mutant), and a C3-cyclelimited transformant of Flaveria bidentis (an antisense ribulose-1,5- bisphosphate carboxylase/oxygenase [Rubisco] small subunit transformant). Data obtained with the C4-cycle-limited mutant showed that atmospheric levels of O2 (20 kPa) caused increased inhibition of photosynthesis as a res...

  14. DETERMINATION OF SENSITIVE SITES IN PHOTOSYNTHESIS DURING LONGTERM PLANT DEHYDRATION

    OpenAIRE

    BRESTIČ, M.

    2002-01-01

    The aim of this work was to measure the net CO2 assimilation, O2 evolution, Rubisco activity, 13C content, actual photochemical PSII efficiency, stomatal conductance, water and osmotic potentials as well as relative water content during increasing plant dehydration. The measurements allowed to determine vulnerability of individual segments of complex process of photosynthesis and characterise the stomatal and non-stomatal responses to dehydration and resistance of mechanisms of photosynthesis...

  15. Dynamic reorganization of photosynthetic supercomplexes during environmental acclimation of photosynthesis

    OpenAIRE

    Minagawa, Jun

    2013-01-01

    Plants and algae have acquired the ability to acclimate to ever-changing environments in order to survive. During photosynthesis, light energy is converted by several membrane protein supercomplexes into electrochemical energy, which is eventually used to assimilate CO2. The efficiency of photosynthesis is modulated by many environmental factors such as quality and quantity of light, temperature, drought, and CO2 concentration, among others. Accumulating evidence indicates that photosynthetic...

  16. From molecules to materials pathways to artificial photosynthesis

    CERN Document Server

    Rozhkova, Elena A

    2015-01-01

    This interdisciplinary book focuses on the various aspects transformation of the energy from sunlight into the chemical bonds of a fuel, known as the artificial photosynthesis, and addresses the emergent challenges connected with growing societal demands for clean and sustainable energy technologies. The editors assemble the research of world-recognized experts in the field of both molecular and materials artificial systems for energy production. Contributors cover the full scope of research on photosynthesis and related energy processes.

  17. GlastCam: A Telemetry-Driven Spacecraft Visualization Tool

    Science.gov (United States)

    Stoneking, Eric T.; Tsai, Dean

    2009-01-01

    Developed for the GLAST project, which is now the Fermi Gamma-ray Space Telescope, GlastCam software ingests telemetry from the Integrated Test and Operations System (ITOS) and generates four graphical displays of geometric properties in real time, allowing visual assessment of the attitude, configuration, position, and various cross-checks. Four windows are displayed: a "cam" window shows a 3D view of the satellite; a second window shows the standard position plot of the satellite on a Mercator map of the Earth; a third window displays star tracker fields of view, showing which stars are visible from the spacecraft in order to verify star tracking; and the fourth window depicts

  18. Compact Atomic Magnetometer for Global Navigation (NAV-CAM)

    Science.gov (United States)

    Bulatowicz, Michael; Larsen, Michael

    2014-05-01

    Northrop Grumman Navigation Systems Division is developing an atom-based magnetometer technology that has the potential for providing a global position reference independent of GPS. The NAV-CAM sensor is a direct outgrowth of the Nuclear Magnetic Resonance Gyro under development by the same technical team. It will be the only known magnetic field sensor capable of providing all 3 axes of magnetic vector direction and magnitude simultaneously with a whole-field scalar measurement, all within a single multi-axis sensing element measuring 4mm cube or smaller, essentially eliminating many of the problems encountered when using physically separate sensors or sensing elements. According to information presented by Ariyur et al. at the 2010 American Control Conference [1], the anticipated accuracy of 10 pico-Tesla (pT) and precision of <0.5 pT of the NAV-CAM sensor will enable magnetic determination of position with 20 meter accuracy and 1 meter resolution.

  19. CAM Modalities Can Stimulate Advances in Theoretical Biology

    Directory of Open Access Journals (Sweden)

    Alex Hankey

    2005-01-01

    Full Text Available Most complementary medicine is distinguished by not being supported by underlying theory accepted by Western science. However, for those who accept their validity, complementary and alternative medicine (CAM modalities offer clues to understanding physiology and medicine more deeply. Ayurveda and vibrational medicine are stimulating new approaches to biological regulation. The new biophysics can be integrated to yield a single consistent theory, which may well underly much of CAM—a true ‘physics of physick’. The resulting theory seems to be a new, fundamental theory of health and etiology. It suggests that many CAM approaches to health care are scientifically in advance of those based on current Western biology. Such theories may well constitute the next steps in our scientific understanding of biology itself. If successfully developed, these ideas could result in a major paradigm shift in both biology and medicine, which will benefit all interested parties—consumers, health professionals, scientists, institutions and governments.

  20. Tooth-colored CAD/CAM monolithic restorations.

    Science.gov (United States)

    Reich, S

    2015-01-01

    A monolithic restoration (also known as a full contour restoration) is one that is manufactured from a single material for the fully anatomic replacement of lost tooth structure. Additional staining (followed by glaze firing if ceramic materials are used) may be performed to enhance the appearance of the restoration. For decades, monolithic restoration has been the standard for inlay and partial crown restorations manufactured by both pressing and computer-aided design and manufacturing (CAD/CAM) techniques. A limited selection of monolithic materials is now available for dental crown and bridge restorations. The IDS (2015) provided an opportunity to learn about and evaluate current trends in this field. In addition to new developments, established materials are also mentioned in this article to complete the picture. In line with the strategic focus of the IJCD, the focus here is naturally on CAD/CAM materials. PMID:26110926

  1. Manganese and the II system in photosynthesis

    International Nuclear Information System (INIS)

    The evolution during greening of some components of system II of photosynthesis has been followed in plastids extracted from Zea mays grown in the dark. Manganese studies were done by means of neutron activation, electron spin resonance (ESR) was also used in some experiments. Oxygen evolution of isolated plastids was followed by polarography (with a membrane electrode). The evolution of manganese/carotenoids ratio can be divided in three parts. During the first hour of greening, the increase shows an input of Mn in the plastids; then, whereas carotenoids content of those plastids presents no changes, Mn is released in the medium; at last, carotenoids synthesis is parallel to Mn fixation in the plastids, the ratio being constant after 24 hours of greening. From various measurements on chloroplastic manganese, it is shown that the development of system II can be divided in two main phases: during the first one (that is during the first day of light) the components are not yet bound together but the relations become more and more strong. Then, during the last period of the development, the organisation of system II is complete and the transformations of the plastids are parallel to the raise of their activity. (author)

  2. Biosynthetic porphyrins and the origin of photosynthesis

    Science.gov (United States)

    Mauzerall, D.; Ley, A.; Mercer-Smith, J. A.

    1986-01-01

    Since the prebiotic atmosphere was anaerobic, if not reducing, a useful function of primordial photosynthesis would have been to photooxidize reduced substrates such as Fe(+2), S(-2) or reduced organic molecules and to emit hydrogen. Experiments have shown that the early biogenic pigments uroporphyrin and coproporphyrin do photooxidize organic compounds and emit hydrogen in the presence of a platinum catalyst. These experiments were carried out in dilute aqueous solution near neutral pH under anaerobic atmosphere, and quantum yields near 10-2 were obtained. Thus relevant prebiotic conditions were maintained. Rather then to further optimize conditions, attempts were made to replace the platinum catalyst by a more prebiotically suitable catalyst. Trials with an Fe4S4(SR)4 cluster, in analogy to the present hydrogenase and nitrogenase, were not successful. However, experiments using cobalt complexes to catalyze the formation of hydrogen are promising. In analogy with biological photosynthetic systems which group pigments, electron transfer molecules and enzymes in clusters for efficiency, it was found that binding the biogenic porphyrins to the polyvinyl alcohol used to support the platinum catalyst did increase the quantum yield of the reaction. It was also found that ultraviolet light can serve to photo-oxidize porphyrinogens to porphyrins under anaerobic conditions. Thus the formation of the colorless porphyriogens by the extraordinarily simple biosynthetic pathway would not be a problem because of the prevalence of UV light in the prebiotic, anoxic atmosphere.

  3. Origin and early evolution of photosynthesis

    Science.gov (United States)

    Blankenship, R. E.

    1992-01-01

    Photosynthesis was well-established on the earth at least 3.5 thousand million years ago, and it is widely believed that these ancient organisms had similar metabolic capabilities to modern cyanobacteria. This requires that development of two photosystems and the oxygen evolution capability occurred very early in the earth's history, and that a presumed phase of evolution involving non-oxygen evolving photosynthetic organisms took place even earlier. The evolutionary relationships of the reaction center complexes found in all the classes of currently existing organisms have been analyzed using sequence analysis and biophysical measurements. The results indicate that all reaction centers fall into two basic groups, those with pheophytin and a pair of quinones as early acceptors, and those with iron sulfur clusters as early acceptors. No simple linear branching evolutionary scheme can account for the distribution patterns of reaction centers in existing photosynthetic organisms, and lateral transfer of genetic information is considered as a likely possibility. Possible scenarios for the development of primitive reaction centers into the heterodimeric protein structures found in existing reaction centers and for the development of organisms with two linked photosystems are presented.

  4. Applications of Satellite Fluorescence to Constrain Global Photosynthesis

    Science.gov (United States)

    Parazoo, Nicholas

    2016-07-01

    Terrestrial gross primary production (GPP) by plant photosynthesis is the largest flux component of the global carbon budget and primary conduit for biological sequestration of atmospheric carbon dioxide. While much is known about the functioning of photosynthesis at the leave-level, gross photosynthetic fluxes are still only loosely constrained at ecosystem, regional, and global scales. Uncertainty in the response of photosynthesis to the environment at these scales is a major source of uncertainty in prediction of biosphere-atmosphere feedbacks under climate change, and thus novel methods are needed to push the boundaries of carbon cycle science beyond leaf-level. Chlorophyll fluorescence has been a major tool for basic research in photosynthesis for nearly a century. It was recently discovered that solar induced fluorescence (SIF) can be accurately retrieved from space using high spectral resolution radiances, providing a new way to study photosynthesis at scales ranging from the ecosystem to the globe. Over the last 5-10 years, satellite based measurements of SIF have provided key new insights into the global distribution and functioning of plant photosynthesis, providing new ways to quantify global GPP, detect regional-scale changes in plant productivity in relation to light use efficiency and environmental controls, disentangle biological contributions to atmospheric carbon dioxide mole fractions, and refine process understanding in terrestrial biosphere models. Here, we highlight some of the key research advances emerging from satellite SIF.

  5. Plasticity of CAM in Aechmea: possibilities and limitations

    OpenAIRE

    Ceusters, Johan

    2008-01-01

    De opwarming van de aarde en het gerelateerde gevaar van een toenemende verwoestijning van semi-aride regio’s in de wereld zullen ongetwijfeld het ecologisch en agronomisch belang van CAM soorten in de toekomst doen toenemen. Een beter begrip van de unieke, flexibele relatie tussen deze groep van planten en hun omgeving is dan ook van essentieel belang. Om hieraan tegemoet te komen werden in deze studie de mogelijkheden en beperkingen van de fotosynthetische flexibiliteit in Aechmea, een typi...

  6. Leaf Damage in CAM bromeliads: a Hydrophysiological Approach

    OpenAIRE

    Londers, Elsje

    2006-01-01

    Bladschade in CAM-bromelia's: een hydrofysiologische studie Het voorkomen van necrotische vlekken op de bladeren van Aechmea planten is een vaak voorkomend probleem in de bromeliateelt. Bladvlekken situer en zich voornamelijk op de bladbocht met uitlopers naar de bladtop. Deze vorm van bladschade doet zich voor in verschillende stadia van de brome lia productieketen; zowel onder serrecondities als tijdens verpakking en transport. Het aantal Aechmea kwekers neemt hierdoor gestaag af, w at onve...

  7. Oclusión y Cad-Cam

    OpenAIRE

    Llombart Jaques, Daniel; Cadafalch Cabaní, Juan; Sabrià, J.; Cortada Colomer, Miquel

    1994-01-01

    Las restauraciones construidas con sistema CAD-CAM, a pesar de sus ventajas, tienen el inconveniente de no dejar una superficie oclusal con las características morfológicas adecuadas. Describimos un sistema, que uniendo al diseño electrónico previo un tallado, que sigue aproximadamente los pasos del tallado selectivo nos permite conseguir una oclusión correcta.

  8. Complete denture fabrication supported by CAD/CAM.

    Science.gov (United States)

    Wimmer, Timea; Gallus, Korbinian; Eichberger, Marlis; Stawarczyk, Bogna

    2016-05-01

    The inclusion of computer-aided design/computer-aided manufacturing (CAD/CAM) technology into complete denture fabrication facilitates the procedures. The presented workflow for complete denture fabrication combines conventional and digitally supported treatment steps for improving dental care. With the presented technique, the registration of the occlusal plane, the determination of the ideal lip support, and the verification of the maxillomandibular relationship record are considered. PMID:26774323

  9. Simulation tools for CAD/CAM robot programming

    OpenAIRE

    Zapletal, Jan

    2014-01-01

    Bachelor’s thesis is focused on simulation, off-line programming and familiarization with KUKA robot. It informs about the composition, coordinate systems and the possibilities of movement of the industrial robot. It introduces methods of on-line and off-line programming and analysis of software for off-line programming aimed on CAD / CAM machining. It describes the creation of specific robot movements and explains the generated code for the implementation of created movements. The result is ...

  10. An approach towards fully integration of CAD and CAM technologies

    OpenAIRE

    M. Tolouei-Rad

    2006-01-01

    Purpose: An integrated CAD/CAM system for milling operations has been developed which helps designers tosolve machining problems at the design stage.Design/methodology/approach: A methodology has been employed which provides all necessary informationfor machining products automatically. Use of these system results in reduced machining leadtimes and costthrough designing machinable components; using available cutting tools; improving machining efficiency. Thesystem is menu driven with a user f...

  11. Potentials for the Modified Cam-Clay model

    OpenAIRE

    Zouain, Nestor; Pontes, Ivaldo; Vaunat, Jean

    2009-01-01

    Abstract Energy and dissipation pseudo-potentials are employed to derive constitutive relationships, in the context of thermodynamic concepts, for the widely used Modified Cam-Clay (MCC) model for soil mechanics. A variational formulation of the MCC evolution equations is proposed in this paper. Since plastic collapse of MCC soils cannot be embedded in the classical limit analysis theory, finding the critical amplification of the load that produces plastic collapse is formulated in...

  12. CamBAfx: workflow design, implementation and application for neuroimaging

    OpenAIRE

    Cinly Ooi; Bullmore, Edward T; Alle-Meije Wink; Levent Sendur; Anna Barnes; Sophie Achard; John Aspden; Sanja Abbott; Shigang Yue; Manfred Kitzbichler; David Meunier; Voichita Maxim; Raymond Salvador; Julian Henty; Roger Tait

    2009-01-01

    CamBAfx is a workflow application designed for both researchers who use workflows to process data (consumers) and those who design them (designers). It provides a front-end (user interface) optimized for data processing designed in a way familiar to consumers. The back-end uses a pipeline model to represent workflows since this is a common and useful metaphor used by designers and is easy to manipulate compared to other representations like programming scripts. As an Eclipse Rich Client Platf...

  13. CamBAfx: Workflow Design, Implementation and Application for Neuroimaging

    OpenAIRE

    Ooi, Cinly; Bullmore, Edward T; Wink, Alle-Meije; Sendur, Levent; Barnes, Anna; Achard, Sophie; Aspden, John; Abbott, Sanja; Yue, Shigang; Kitzbichler, Manfred; Meunier, David; Maxim, Voichita; Salvador, Raymond; Henty, Julian; Tait, Roger

    2009-01-01

    CamBAfx is a workflow application designed for both researchers who use workflows to process data (consumers) and those who design them (designers). It provides a front-end (user interface) optimized for data processing designed in a way familiar to consumers. The back-end uses a pipeline model to represent workflows since this is a common and useful metaphor used by designers and is easy to manipulate compared to other representations like programming scripts. As an Eclipse Rich Client Platf...

  14. Development of a Feature Based CAM System for Rotational Parts

    OpenAIRE

    Yakup YILDIZ; İhsan KORKUT; ŞEKER, Ulvi

    2010-01-01

    Computer Aided Process Planning (CAPP) plays an  important role in the development of Computer Integrated Manufacturing systems (CIM) and provides a vital link  between Computer Aided Design (CAD) and Computer Aided Manufacturing (CAM). Automatic extraction and recognition of part features directly from a CAD database also strengthen the link between CAD and CAPP. In this study, an automatic feature recognition and CNC code generation (AFR/ACCG) system  was developed for rotati...

  15. CAM Modalities Can Stimulate Advances in Theoretical Biology

    OpenAIRE

    Alex Hankey

    2005-01-01

    Most complementary medicine is distinguished by not being supported by underlying theory accepted by Western science. However, for those who accept their validity, complementary and alternative medicine (CAM) modalities offer clues to understanding physiology and medicine more deeply. Ayurveda and vibrational medicine are stimulating new approaches to biological regulation. The new biophysics can be integrated to yield a single consistent theory, which may well underly much of CAM—a true ‘...

  16. Application of CAD/CAM at VEB Lufttechnische Anlagen Berlin

    Energy Technology Data Exchange (ETDEWEB)

    Nitsch, B.; Aschenbrenner, H.J.

    1987-01-01

    This contribution presents the concept for the introduction of CAD/CAM systems to an enterprise of Kombinat ILKA Luft- und Kaeltetechnik. This concept is based on the use of a local computer network with a K 1630 microcomputer as the central computer and multi-terminals in the special departments. Special reference is made to the problems of the structured or modular software development and the work with centralised data files.

  17. Human Face Detection and Recognition using Web-Cam

    Directory of Open Access Journals (Sweden)

    Petcharat Pattanasethanon

    2012-01-01

    Full Text Available Problem statement: The illuminance insensitivity that reflects the angle of human facial aspects occurs once the distance between the object and the camera is too different such as animated images. This has been a problem for facial recognition system for decades. Approach: For this reason, our study represents a novel technique for facial recognition through the implementation of Successes Mean Quantization Transform and Spare Network of Winnow with the assistance of Eigenface computation. After having limited the frame of the input image or images from Web-Cam, the image is cropped into an oval or eclipse shape. Then the image is transformed into greyscale color and is normalized in order to reduce color complexities. We also focus on the special characteristics of human facial aspects such as nostril areas and oral areas. After every essential aspectsarescrutinized, the input image goes through the recognition system for facial identification. In some cases where the input image from the Web-Cam does not exist in the database, the user will be notified for the error handled. However, in cases where the image exists in the database, that image will be computed for similarity measurement using Euclidean Distance measure from the input image. Results and Conclusion: The result of our experiment reveals that the recognition process of 150 images in the database and 10 images from the Web-Cam provides 100% accuracy in terms of recognition. The runtime in this case is at 0.04 sec.

  18. CAMS as a tool for human factors research in spaceflight

    Science.gov (United States)

    Sauer, Juergen

    2004-01-01

    The paper reviews a number of research studies that were carried out with a PC-based task environment called Cabin Air Management System (CAMS) simulating the operation of a spacecraft's life support system. As CAMS was a multiple task environment, it allowed the measurement of performance at different levels. Four task components of different priority were embedded in the task environment: diagnosis and repair of system faults, maintaining atmospheric parameters in a safe state, acknowledgement of system alarms (reaction time), and keeping a record of critical system resources (prospective memory). Furthermore, the task environment permitted the examination of different task management strategies and changes in crew member state (fatigue, anxiety, mental effort). A major goal of the research programme was to examine how crew members adapted to various forms of sub-optimal working conditions, such as isolation and confinement, sleep deprivation and noise. None of the studies provided evidence for decrements in primary task performance. However, the results showed a number of adaptive responses of crew members to adjust to the different sub-optimal working conditions. There was evidence for adjustments in information sampling strategies (usually reductions in sampling frequency) as a result of unfavourable working conditions. The results also showed selected decrements in secondary task performance. Prospective memory seemed to be somewhat more vulnerable to sub-optimal working conditions than performance on the reaction time task. Finally, suggestions are made for future research with the CAMS environment.

  19. Evaluating rare amino acid substitutions (RGC_CAMs in a yeast model clade.

    Directory of Open Access Journals (Sweden)

    Kenneth Polzin

    Full Text Available When inferring phylogenetic relationships, not all sites in a sequence alignment are equally informative. One recently proposed approach that takes advantage of this inequality relies on sites that contain amino acids whose replacement requires multiple substitutions. Identifying these so-called RGC_CAM substitutions (after Rare Genomic Changes as Conserved Amino acids-Multiple substitutions requires that, first, at any given site in the amino acid sequence alignment, there must be a minimum of two different amino acids; second, each amino acid must be present in at least two taxa; and third, the amino acids must require a minimum of two nucleotide substitutions to replace each other. Although theory suggests that RGC_CAM substitutions are expected to be rare and less likely to be homoplastic, the informativeness of RGC_CAM substitutions has not been extensively evaluated in biological data sets. We investigated the quality of RGC_CAM substitutions by examining their degree of homoplasy and internode certainty in nearly 2.7 million aligned amino acid sites from 5,261 proteins from five species belonging to the yeast Saccharomyces sensu stricto clade whose phylogeny is well-established. We identified 2,647 sites containing RGC_CAM substitutions, a number that contrasts sharply with the 100,887 sites containing RGC_non-CAM substitutions (i.e., changes between amino acids that require only a single nucleotide substitution. We found that RGC_CAM substitutions had significantly lower homoplasy than RGC_non-CAM ones; specifically RGC_CAM substitutions showed a per-site average homoplasy index of 0.100, whereas RGC_non-CAM substitutions had a homoplasy index of 0.215. Internode certainty values were also higher for sites containing RGC_CAM substitutions than for RGC_non-CAM ones. These results suggest that RGC_CAM substitutions possess a strong phylogenetic signal and are useful markers for phylogenetic inference despite their rarity.

  20. Overexpression of EpCAM in uterine serous papillary carcinoma: implications for EpCAM-specific immunotherapy with human monoclonal antibody adecatumumab (MT201).

    Science.gov (United States)

    El-Sahwi, Karim; Bellone, Stefania; Cocco, Emiliano; Casagrande, Francesca; Bellone, Marta; Abu-Khalaf, Maysa; Buza, Natalia; Tavassoli, Fattaneh A; Hui, Pei; Rüttinger, Dominik; Silasi, Dan-Arin; Azodi, Masoud; Schwartz, Peter E; Rutherford, Thomas J; Pecorelli, Sergio; Santin, Alessandro D

    2010-01-01

    We evaluated the expression of epithelial cell adhesion molecule (EpCAM) and the potential of MT201 (adecatumumab), a human monoclonal antibody against EpCAM, in uterine serous papillary carcinoma (USPC). EpCAM expression was evaluated by real-time PCR and immunohistochemistry in a total of 56 USPC fresh-frozen biopsies and paraffin-embedded tissues. EpCAM surface expression was also evaluated by flow cytometry and immunohistochemistry in six USPC cell lines. Sensitivity to MT201 antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity was tested against a panel of primary USPC cell lines expressing different levels of EpCAM in standard 5-h (51)Cr release assays. EpCAM transcript was significantly overexpressed in fresh-frozen USPC when compared with normal endometrial cells (NEC). Median (minimum-maximum) copy number was 943.8 (31.5-1568.3) in tumor samples versus 12.9 (1.0-37.0) in NEC (P < 0.001). By immunohistochemistry, EpCAM expression was found in 96% (26 out of 27) of USPC samples with significantly higher expression compared with NECs (P < 0.001). High surface expression of EpCAM was found in 83% (five out of six) of the USPC cell lines tested by flow cytometry. EpCAM-positive cell lines were found highly sensitive to MT201-mediated antibody-dependent cellular cytotoxicity in vitro, whereas primary USPC cell lines were resistant to natural killer cell-dependent cytotoxicity. Human plasma IgG did not significantly inhibit MT201-mediated cytotoxicity against USPC. EpCAM is highly expressed in uterine serous carcinoma at mRNA and protein levels, and primary USPC are highly sensitivity to MT201-mediated cytotoxicity. MT201 might represent a novel therapeutic strategy in patients harboring advanced/recurrent or metastatic USPC refractory to standard treatment modalities. PMID:20053761

  1. ChemCam Passive Reflectance Spectroscopy at Gale Crater, Mars

    Science.gov (United States)

    Johnson, J. R.; Bell, J. F.; Cloutis, E.; Bender, S.; Blaney, D. L.; Ehlmann, B. L.; Gasnault, O.; Kinch, K. M.; Le Mouelic, S.; Rice, M. S.; Wiens, R. C.; DeFlores, L.; Team, M.

    2013-12-01

    The Laser-Induced Breakdown Spectrometer (LIBS) portion of the ChemCam instrument on the Mars Science Laboratory Curiosity rover uses 3 dispersive spectrometers to cover the ultraviolet (240-342 nm), visible (382-469 nm) and visible/near-infrared (474-906 nm) spectral regions at high spectral (spectra (acquired with the LIBS laser off) used to remove the background signal from the LIBS measurement. Similar 'passive' observations of the ChemCam calibration target holder can be made at similar times of day and at identical exposure times (to minimize variations from dark current). Because this target exhibits ~95% flat reflectance in the ~400-900 nm region, radiance spectra ratios (surface/calibration target) can be normalized to known calibration target lab spectra to produce relative reflectance spectra (400-900 nm) with an estimated accuracy of 10-20%. Initial results replicated the known spectral shape and overall reflectance values of the ChemCam calibration targets and green color chip on the Mastcam calibration target. Dust contamination was evident, although dust on the ChemCam calibration targets is minimized by their tilted placement on the rover deck. All ChemCam targets that were sunlit during LIBS acquisition (~80% of all measurements) provide 'dark' spectra for which relative reflectance spectra can be obtained. Owing to the dusty nature of the Gale landing sites, passive spectra observed to date exhibit spectral shapes indicative of ferric phases, similar to spectra of palagonitic soils. Most spectra are bracketed in reflectance by typical 'bright' and 'dark' spectra from the OMEGA and CRISM orbital spectrometers. Preliminary Mastcam reflectance spectra are similar, providing additional confidence regarding the first-order calibration of the ChemCam spectra. The spectral similarity to palagonitic soils is consistent with the results from the CheMin instrument for Rocknest sands. Changes in the 535 nm band depth are likely indicative of differences in

  2. Path of Carbon in Photosynthesis III.

    Science.gov (United States)

    Benson, A. A.; Calvin, M.

    1948-06-01

    Although the overall reaction of photosynthesis can be specified with some degree of certainty (CO{sub 2} + H{sub 2}O + light {yields} sugars + possibly other reduced substances), the intermediates through which the carbon passes during the course of this reduction have, until now, been largely a matter of conjecture. The availability of isotopic carbon, that is, a method of labeling the carbon dioxide, provides the possibility of some very direct experiments designed to recognize these intermediates and, perhaps, help to understand the complex sequence and interplay of reactions which must constitute the photochemical process itself. The general design of such experiments is an obvious one, namely the exposure of the green plant to radioactive carbon dioxide and light under a variety of conditions and for continually decreasing lengths of time, followed by the identification of the compounds into which the radioactive carbon is incorporated under each condition and time period. From such data it is clear that in principle, at least, it should be possible to establish the sequence of compounds in time through which the carbon passes on its path from carbon dioxide to the final products. In the course of shortening the photosynthetic times, one times, one ultimately arrives at the condition of exposing the plants to the radioactive carbon dioxide with a zero illumination time, that is, in the dark. Actually, in the work the systematic order of events was reversed, and they have begun by studying first the dark fixation and then the shorter photosynthetic times. The results of the beginnings of this sort of a systematic investigation are given in Table I which includes three sets of experiments, namely a dark fixation experiment and two photosynthetic experiments, one of 30 seconds duration and the other of 60 seconds duration.

  3. Understanding dental CAD/CAM for restorations--the digital workflow from a mechanical engineering viewpoint.

    Science.gov (United States)

    Tapie, L; Lebon, N; Mawussi, B; Fron Chabouis, H; Duret, F; Attal, J-P

    2015-01-01

    As digital technology infiltrates every area of daily life, including the field of medicine, so it is increasingly being introduced into dental practice. Apart from chairside practice, computer-aided design/computer-aided manufacturing (CAD/CAM) solutions are available for creating inlays, crowns, fixed partial dentures (FPDs), implant abutments, and other dental prostheses. CAD/CAM dental solutions can be considered a chain of digital devices and software for the almost automatic design and creation of dental restorations. However, dentists who want to use the technology often do not have the time or knowledge to understand it. A basic knowledge of the CAD/CAM digital workflow for dental restorations can help dentists to grasp the technology and purchase a CAM/CAM system that meets the needs of their office. This article provides a computer-science and mechanical-engineering approach to the CAD/CAM digital workflow to help dentists understand the technology. PMID:25911827

  4. Demand for CAM Practice at Hospitals in Japan: A Population Survey in Mie Prefecture

    OpenAIRE

    Toshihiro Togo; Shigeru Urata; Kenta Sawazaki; Hinata Sakuraba; Torao Ishida; Kazuhito Yokoyama

    2011-01-01

    Complementary and alternative medicine (CAM) therapies have been provided at hospitals along with conventional medicine in industrialized nations. Previous studies conducted in Japan revealed high proportion of Japanese had experience of using CAM, but failed to discuss how it should be provided. The present study aims to clarify the demand for CAM practice at hospitals in Japan. A questionnaire consisting of 41 questions was mailed to 10 000 adults randomly selected from the electoral roll o...

  5. Demand for CAM Practice at Hospitals in Japan: A Population Survey in Mie Prefecture

    Directory of Open Access Journals (Sweden)

    Toshihiro Togo

    2011-01-01

    Full Text Available Complementary and alternative medicine (CAM therapies have been provided at hospitals along with conventional medicine in industrialized nations. Previous studies conducted in Japan revealed high proportion of Japanese had experience of using CAM, but failed to discuss how it should be provided. The present study aims to clarify the demand for CAM practice at hospitals in Japan. A questionnaire consisting of 41 questions was mailed to 10 000 adults randomly selected from the electoral roll of Mie prefecture, Japan in January 2007. The questionnaire asked the subjects about demand for CAM practice at hospitals, types of CAM therapy to be provided and associated reasons. Sociodemographic characteristics, perceived health status, experience and purpose of CAM use, and information resource for CAM were also surveyed. Completed answers were collected from 2824 (28.6% respondents. Two thousand and nineteen (71.5% of the respondents demanded CAM practice at hospitals with the most likely reason of “patients can receive treatment under the guidance of a physicians”. The three most popular CAM therapies were Kampo, acupressure/massage/Shiatsu and acupuncture/moxibustion. The demand was positively associated with gender, ages of 40–59 years, annual household incomes of 5–7 million yen, occupation of specialist and technical workers and sales workers and poor health status. Higher demand was observed among those who used both CAM and conventional medical therapies for curative purposes. In conclusion, Japanese show a high demand for CAM practice, hoping to use CAM for curative purposes with monitoring by physicians at hospitals.

  6. A Space Cam Mechanism for Power Transmission of an Opposite-cylinder Piston Engine

    OpenAIRE

    Zhang Haoyue; Xu Xiaojun; Zhang Lei; Zhou Faliang

    2015-01-01

    For the purpose of improving the engine’s power density, we put forward a new type of power transmission mechanism which is used for opposed-cylinder engine. The gas pressure acts on the cam through the piston and push rod, and the spindle rotation of external is driven by the cam. The design of spatial cam work surface is completed by using the enveloping theory of a family of space curves, the force between roller and cam is analyzed using dynamic analysis software. Under the condition of e...

  7. The use of CAM by women suffering from nausea and vomiting during pregnancy

    Directory of Open Access Journals (Sweden)

    Smith Michael

    2002-05-01

    Full Text Available Abstract Background Nausea and vomiting during pregnancy (NVP affects two-thirds of pregnant women to varying degrees and over the years many modalities have been used to try to alleviate this often debilitating condition. There is a paucity of information in the literature about the use or efficacy of complementary and alternative medicine (CAM for the treatment of this condition that affects so many women. Our primary objective was to examine the prevalence of CAM usage by women suffering from NVP. Our secondary objective was to ascertain if women had any supervision in the use of these treatments. Methods Women who called The Motherisk NVP helpline, were asked after the counseling session to complete a questionnaire, which included demographic data as well as information about their CAM use. Results Seventy women completed the questionnaire. 61% reported using CAM therapies, of which the three most popular were: ginger, vitamin B6 and acupressure. 21% of those who reported using CAM, had consulted CAM practitioners, 8% their physicians or pharmacists and 71% discussed the usage with family, friends and other allied health professionals. Women who did not use CAM stated they would probably use these modalities if there was more information about the safety in pregnancy. Conclusion Pregnant women with NVP are mirroring the trend in the general population of the use of CAM. They are also using CAM therapies with little supervision from practitioners experienced in the use of these modalities.

  8. ON DESIGN METHOD OF THE PRECISION CAM PROFILE WITH RANDOM PROCESSING ERRORS

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Based on probability and statistic, a design method of precision cam profile concerning the influence of random processing errors is advanced. Combining the design with the process, which can be used to predict that cam profiles will be successfully processed or not in the design stage, design of the cam can be done by balancing the economization and reliability. In addition, an fuzzy deduction method based on Bayers formula is advanced to estimate processing reasonable of the designed precision cam profile, and it take few samples.

  9. Hot-spot residues in the cytochrome P450cam-putidaredoxin binding interface.

    Science.gov (United States)

    Hiruma, Yoshitaka; Gupta, Ankur; Kloosterman, Alexander; Olijve, Caroline; Olmez, Betül; Hass, Mathias A S; Ubbink, Marcellus

    2014-01-01

    Cytochrome P450cam (P450cam) is a heme-containing monooxygenase that catalyzes the hydroxylation of D-camphor to produce 5-exo-hydroxycamphor. The catalytic cycle of P450cam requires two electrons, both of which are donated by putidaredoxin (Pdx), a ferredoxin containing a [2 Fe-2 S] cluster. Atomic-resolution structures of the Pdx-P450cam complex have recently been solved by X-ray crystallography and paramagnetic NMR spectroscopy. The binding interface showed the potential electron transfer pathways and interactions between Pdx Asp38 and P450cam Arg112, as well as hydrophobic contacts between the Pdx Trp106 and P450cam residues. Several polar residues not previously recognized as relevant for binding were found in the interface. In this study, site-directed mutagenesis, kinetic measurements, and NMR studies were employed to probe the energetic importance and role of the polar residues in the Pdx-P450cam interaction. A double mutant cycle (DMC) analysis of kinetic data shows that favorable interactions exist between Pdx Tyr33 and P450cam Asp125, as well as between Pdx Ser42 and P450cam His352. The results show that alanine substitutions of these residues and several others do not influence the rates of electron transfer. It is concluded that these polar interactions contribute to partner recognition rather than to electronic coupling of the redox centers. PMID:24302683

  10. Initiating a Reiki or CAM program in a healthcare organization--developing a business plan.

    Science.gov (United States)

    Vitale, Anne

    2014-01-01

    Complementary and alternative medicine (CAM) services, such as Reiki, continue to be offered to consumers in many hospitals and other health care organizations. There is growing interest among nurses, doctors, and other health care providers for the integration of CAM therapies into traditional settings. Health care organizations are responding to this need but may not know how to start CAM programs. Starting a Reiki program in a health care setting must be envisioned in a business model approach. This article introduces nurses and other health care providers to the basic concepts of business plan development and important steps to follow when starting a Reiki or CAM program. PMID:25314111

  11. Operability of the Ventilation Continuous Air Monitor (CAM) Interlock Analysis of Proposed Upgrade to the 241AW Farm Primary Exhauster CAM System

    International Nuclear Information System (INIS)

    The Tank Farms Final Safety Analysis (FSAR) assumes that a ventilation stack Continuous Air Monitor (CAM) interlock system detects high radiation in the exhaust stream and shuts off the associated ventilation system within 10 minutes of a High-Efficiency Particulate Air (HEPA) filter system failure (CHG, 2002). Previous analysis of the as-built CAM system on the AW Farm Primary Exhauster (stack 296-A-27) showed that this system potentially required significantly longer than 10 minutes to detect a HEPA filter failure and initiate shutdown of the ventilation system (Short, 2002). The purpose of this report is to determine the CAM interlock system response time for a proposed upgrade of the 296-A-27 CAM system. The approach to be used in this analysis is essentially the same as used in RPP-10799, Rev. 0 (Short, 2002), which is to conservatively estimate the time required by the proposed upgraded CAM sampling/monitoring system to detect a FSAR-defined HEPA filter failure and automatically shutdown the exhaust fan. For the HEPA filter failure over-temperature accident scenario in the FSAR, the upgraded CAM system on the AW Farm Primary Exhauster will require significantly less than 10 minutes to detect a HEPA filter failure, actuate the CAM Interlock, and shutdown the exhauster fan. Therefore, the analyzed system is adequate to meet the operability requirements specified in the FSAR and the Tank Farms Technical Safety Requirements (CHG, 2001; CHG, 2002)

  12. Ecology and ecophysiology of tree stems: corticular and wood photosynthesis

    Science.gov (United States)

    Pfanz, H.; Aschan, G.; Langenfeld-Heyser, R.; Wittmann, C.; Loose, M.

    2002-03-01

    Below the outer peridermal or rhytidomal layers, most stems of woody plants possess greenish tissues. These chlorophyll-containing tissues (the chlorenchymes) within the stems are able to use the stem internal CO2 and the light penetrating the rhytidome to photoassimilate and produce sugars and starch. Although net photosynthetic uptake of CO2 is rarely found, stem internal re-fixation of CO2 in young twigs and branches may compensate for 60-90% of the potential respiratory carbon loss. Isolated chlorenchymal tissues reveal rather high rates of net photosynthesis (being up to 75% of the respective rates for leaf photosynthesis). Corticular photosynthesis is thus thought to be an effective mechanism for recapturing respiratory carbon dioxide before it diffuses out of the stem. Furthermore, chloroplasts of the proper wood or pith fraction also take part in stem internal photosynthesis. Although there has been no strong experimental evidence until now, we suggest that the oxygen evolved during wood or pith photosynthesis may play a decisive role in avoiding/reducing stem internal anaerobiosis.

  13. Photosynthesis 2008 Gordon Research Conferences - June 22-27, 2008

    Energy Technology Data Exchange (ETDEWEB)

    Willem Vermaas

    2009-08-28

    Photosynthesis is the most prevalent, natural way to convert solar energy to chemical energy in living systems, and is a major mechanism to ameliorate rising CO2 levels in the atmosphere and to contribute to sustainable biofuels production. Photosynthesis is a particularly interdisciplinary field of research, with contributions from plant and microbial physiology, biochemistry, spectroscopy, etc. The Photosynthesis GRC is a venue by which scientists with expertise in complementary approaches such as solar energy conversion, molecular mechanisms of electron transfer, and 'systems biology' (molecular physiology) of photosynthetic organisms come together to exchange data and ideas and to forge new collaborations. The 2008 Photosynthesis GRC will focus on important new findings related to, for example: (1) function, structure, assembly, degradation, motility and regulation of photosynthetic complexes; (2) energy and electron transfer in photosynthetic systems; regulation and rate limitations; (3) synthesis, degradation and regulation of cofactors (pigments, etc.); (4) functional, structural and regulatory interactions between photosynthesis and the physiology of the organism; (5) organisms with unusual photosynthetic properties, and insights from metagenomics and evolution; and (6) bioenergy strategies involving solar energy conversion, and practical applications for photosynthetic organisms.

  14. An Investigation of the Afternoon Decline in Tropical Forest Photosynthesis

    Science.gov (United States)

    Doughty, C.; Goulden, M. L.; Miller, S. D.; Menton, M. C.; da Rocha, H.; Freitas, H.; Figueira, M. A.; da Sousa, C. A.; Maia, A.

    2002-12-01

    The recent use of eddy covariance to measure the net exchange of CO2 between the atmosphere and a tropical forest in Santarem Para, Brazil, has indicated a substantial decline in forest photosynthesis in the afternoon, even after taking light differences into account. Afternoon declines in leaf-level gas exchange have been reported for many ecosystems, including tropical forests. Potential causes for this decline include stomatal responses to VPD, low leaf water potential, changes in biochemistry due to elevated temperature, photoinhibition, photorespiration, or intrinsic circadian rhythm. This study attempts to understand this decline by using leaf gas exchange to measure photosynthesis while canopy leaves are kept under constant light, humidity, and temperature conditions for 24 to 36 hours hours.At constant light levels of 100 PAR æmol~m-2s-1, 7 of 12 species tested showed a substantial decline photosynthesis at night, and a subsequent recovery in photosynthesis during the next day. In most cases, the internal CO2 of these plants increased at night, indicating that this diel cycle was not simply an effect of a circadian rhythm in stomatal conductance. Rather, the photosynthesis of a significant fraction of the plants surveyed appears to be under the direct control of a circadian oscillator.

  15. Observed and predicted measurements of photosynthesis in a phytoplankton culture exposed to natural irradiance

    International Nuclear Information System (INIS)

    Photosynthesis-irradiance (P-I) curves were produced (using artificial illumination) from samples taken at one or more times per day from a continuous culture illuminated with sunlight. The continuous culture housed an oxygen electrode used to measure photosynthesis semi-continuously. Rates of photosynthesis predicted from P-I curves agreed with photosynthesis observed in the culture only for days of low irradiance. For sunny days or for days of variable irradiance, P-I curves predicted neither the morning photosynthesis maximum nor the afternoon depression. Daily integrals of predicted and observed photosynthesis, however, were probably within the possible errors of measurement. (orig.)

  16. SIMPLE SIMULATION OF THE ANNUAL VARIATION OF THE SPECIFIC PHOTOSYNTHESIS RATE IN JIAOZHOU BAY

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A simple diagnostic simulation of the annual cycling of the surface specific photosynthesis rate (SPR) in Jiaozhou Bay is described in this paper. Light intensity, temperature and nutrients (nitrate + ammonia, phosphate) were considered as main factors controlling photosynthesis of phytoplankton and were introduced into the model by different function equations. The simulated variation of specific photosynthesis rate coincided with the measured data. Analysis of the effect of every factor on photosynthesis indicated that the variation of photosynthesis rate was controlled by all these three factors, while temperature showed good correlation with SPR as measurement showed. This diagnostic simulation yielded the values of some parameter relating with the photosynthesis in Jiaozhou Bay.

  17. The Path of Carbon in Photosynthesis XVI. Kinetic Relationships of the Intermediates in Steady State Photosynthesis

    Science.gov (United States)

    Benson, A. A.; Kawaguchi, S.; Hayes, P.; Calvin, M.

    1952-06-05

    A kinetic study of the accumulation of C{sup 14} in the intermediates of steady state photosynthesis in C{sup 14}O{sub 2} provides information regarding the sequence of reactions involved. The work described applied the radio-chromatographic technique for analysis of the labeled early products. The simultaneous carboxylation reaction resulting in malic acid as well as phosphoglycerate is demonstrated in experiments at high light intensity. A comparison of radioactivities in a number of phosphorylated sugars as a function of time reveals concurrent synthesis of fructose and sedoheptulose phosphates followed by that of ribulose phosphates and later by that of glucose phosphates. The possibility that the cleavage of C{sub 4} compounds to C{sub 2} carbon dioxide acceptors may involve C{sub 7} and C{sub 5} sugars and evidence for this mechanism is presented.

  18. ChemCam Passive Spectroscopy of the Martian Atmosphere

    Science.gov (United States)

    McConnochie, T. H.; Smith, M. D.; Wolff, M. J.; Bender, S. C.; Johnson, J. R.; Wiens, R. C.; Maurice, S.; Gasnault, O.; Barraclough, B. L.; Blaney, D. L.; DeFlores, L.; Team, M.

    2013-12-01

    The design priority of the Laser-Induced Breakdown Spectrometer (LIBS) portion of the ChemCam instrument (Wiens et al. 2012, Space Sci, Rev. 170) on the Mars Science Laboratory (MSL) Curiosity rover is its active mode, which acquires spectra of a laser induced plasma using three spectrometers. However these same spectrometers have excellent sensitivity to ambient light and so are also used independent of the laser in 'passive' mode to acquire spectra of the Martian surface (Johnson et al., 2013, LPSC #1372) and, as we will describe here, the Martian sky. Using ChemCam passive sky observations, we have successfully measured the column abundance of water vapor, molecular oxygen, and carbon dioxide gas, and with further analysis will likely be able to constrain the column abundance of ozone as well as aerosol and cloud particle properties. Although data analysis is ongoing, we currently estimate a 2 sigma precision of oxygen, and < +/- 4 % for carbon dioxide. The three ChemCam spectrometers span 240-342 nm, 382-469 nm, and 474-906 nm, respectively, with a resolution of 0.6 nm FWHM or better. Passive sky observations were obtained on sols 131, 230, and then at regular ~7 sol intervals starting on sol 278. The observation consists of acquiring spectra of light scattered by the atmosphere at two elevation angles so that the ratio of the two resulting radiance spectra yields (after removing the continuum) an extremely precise absorption spectrum with both the solar spectrum and instrument response uncertainties removed. To yield column abundances, the spectra are modeled with a discrete ordinates multiple scattering radiative transfer code that incorporates gas absorption via the correlated-k method.

  19. FEAT-REP : representing features in CAD/CAM

    OpenAIRE

    Klauck, Christoph; Bernardi, Ansgar; Legleitner, Ralf

    1991-01-01

    When CAD/CAM experts view a workpiece, they perceive it in terms of their own expertise. These terms, called features, which are build upon a syntax (geometry) and a semantic (e.g. skeletal plans in manufacturing or functional relations in design), provide an abstraction mechanism to facilitate the creation, manufacturing and analysis of workpieces. Our goal is to enable experts to represent their own feature-language via a feature-grammar in the computer to build feature-based systems e.g. C...

  20. CAD/CAM from the graphic-design perspective

    Energy Technology Data Exchange (ETDEWEB)

    Marcus, A.

    1982-11-01

    CAD/CAM systems have evolved elaborate human-computer interfaces in order to facilitate the creation of highly detailed and specialized schematic diagrams and texts. Although these systems have powerful capacities in terms of graphics editing, data manipulation, and data storage, insufficient attention has been given to making the online interface (together with supporting documentation) user-friendly, i.e., understandable, memorable, and appealing to the general user. Graphic-design considerations in particular have been routinely overlooked. Graphic design concerns typography, symbol design, color, spatial layout, and temporal sequencing. Graphic design can assist computer science by providing insight and expertise in designing effective communication between human being and machine.

  1. Status of the NectarCAM camera project

    OpenAIRE

    Barrio Uña, Juan Abel; Herranz, D.; Tejedor, L. A.

    2014-01-01

    NectarCAM is a camera designed for the medium-sized telescopes of the Cherenkov Telescope Array (CTA) covering the central energy range 100 GeV to 30 TeV. It has a modular design based on the NECTAr chip, at the heart of which is a GHz sampling Switched Capacitor Array and 12-bit Analog to Digital converter. The camera will be equipped with 265 7-photomultiplier modules, covering a field of view of 7 to 8 degrees. Each module includes the photomultiplier bases, High Voltage supply, pre-amplif...

  2. Korištenje CAD/CAM tehnologije u praksi

    OpenAIRE

    Jolić, Robert; Kukec, Đuro; Pavlic, Tomislav

    2014-01-01

    Ovaj rad opisuje korakeristike CNC tehnologije, njeno korištenje i prednosti korištenja u proizvodnji. Opisana je ideja, izrada 3D modela u CAD programskome alatu, zatim su u CAM programskome alatu definirani svi parametri glodanja i na kraju je sve glodano na stroju. Prikazano je koliko se brže ovom tehnologijom proizvod može koristiti i proizvoditi, u odnosu na način da se sve radi ručno. Sve je modelirano u programskome alatu SolidWorks, parametri glodanja su definirani u programskome alat...

  3. Creative WebCam Live最新摄像头

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Creative WebCam Live摄像头拥有高达1024×768的静态影像捕捉能力,进了步提供无与伦比的影像输出效果。另外.其更拥有灵活的固定方式,让你可以轻轻松松将它固定在PC,不同厚度的LCD屏幕甚至是Notebook上。不仅如此,

  4. CAD/CAM and scientific data management at Dassault

    Science.gov (United States)

    Bohn, P.

    1984-01-01

    The history of CAD/CAM and scientific data management at Dassault are presented. Emphasis is put on the targets of the now commercially available software CATIA. The links with scientific computations such as aerodynamics and structural analysis are presented. Comments are made on the principles followed within the company. The consequences of the approximative nature of scientific data are examined. Consequence of the new history function is mainly its protection against copy or alteration. Future plans at Dassault for scientific data appear to be in opposite directions compared to some general tendencies.

  5. Applying DER-CAM for IIT Microgrid Explansion Planning

    Energy Technology Data Exchange (ETDEWEB)

    Shahidehpour, Mohammad [Illinois Inst. of Technology, Chicago, IL (United States); Li, Zuyi [Illinois Inst. of Technology, Chicago, IL (United States); Wang, Jianhui [Argonne National Lab. (ANL), Argonne, IL (United States); Chen, Chen [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-04-19

    The Distributed Energy Resources Customer Adoption Model (DER-CAM) is an economic and environmental model of customer DER adoption. This model has been in development at the Lawrence Berkeley National Laboratory since 2000. The objective of the model is to find optimal DER investments while minimizing total energy costs or carbon dioxide (CO2) emissions, or achieving a weighted objective that simultaneously considers both criteria. The Illinois Institute of Technology (IIT) Microgrid project started in August 2008, and the majority of the project was completed in May 2013. IIT Microgrid, funded mostly by a grant from the U.S. Department of Energy as well as State and philanthropic contributions, empowers the campus consumers with the objective of establishing a smart microgrid that is highly reliable, economically viable, environmentally friendly, fuel-efficient, and resilient in extreme circumstances with a self-healing capability. In this project, we apply DER-CAM to study the expansion planning of the IIT Microgrid. First, the load data, environmental data, utility data, and technology data for the IIT Microgrid are gathered and organized to follow the DER-CAM input requirements. Then, DERCAM is applied to study the expansion planning of the IIT Microgrid for different cases, where different objectives in DER-CAM and different utility conditions are tested. Case 1 considers the objective of minimizing energy costs with fixed utility rates and 100% electric utility availability. Case 2 considers the objective of minimizing energy costs with real-time utility rates and 4 emergency weeks when the IIT Microgrid does not have access to the electric utility grid and has to operate in island mode. In Case 3, the utility rates are restored to fixed values and 100% electric utility availability is assumed, but a weighted multi-objective (Obj: a × costs + b × CO2 emissions, where a and b are weights for cost minimization and CO2 emissions minimization) is utilized to

  6. Method and apparatus for nondestructive in vivo measurement of photosynthesis

    Science.gov (United States)

    Greenbaum, Elias

    1988-01-01

    A device for in situ, nondestructive measurement of photosynthesis in live plants and photosynthetic microorganisms is disclosed which comprises a Clark-type oxygen electrode having a substantially transparent cathode comprised of an optical fiber having a metallic grid microetched onto its front face and sides, an anode, a substantially transparent electrolyte film, and a substantially transparent oxygen permeable membrane. The device is designed to be placed in direct contact with a photosynthetic portion of a living plant, and nondestructive, noninvasive measurement of photosynthetic oxygen production from the plant can be taken by passing light through the fiber-optic cathode, transparent electroyte and transparent membrane, and onto the plant so that photosynthesis occurs. The oxygen thus produced by the plant is measured polargraphically by the electrode. The present invention allows for rapid, nondestructive measurements of photosynthesis in living plants in a manner heretofore impossible using prior art methods.

  7. DETERMINATION OF SENSITIVE SITES IN PHOTOSYNTHESIS DURING LONGTERM PLANT DEHYDRATION

    Directory of Open Access Journals (Sweden)

    M BRESTIČ

    2002-05-01

    Full Text Available The aim of this work was to measure the net CO2 assimilation, O2 evolution, Rubisco activity, 13C content, actual photochemical PSII efficiency, stomatal conductance, water and osmotic potentials as well as relative water content during increasing plant dehydration. The measurements allowed to determine vulnerability of individual segments of complex process of photosynthesis and characterise the stomatal and non-stomatal responses to dehydration and resistance of mechanisms of photosynthesis to gradual water stress. The sensitiveness of stomata, osmoprotection and isotopic 13C discrimination seem to be the most interesting parameters which act dynamically in plant acclimation to drought. They may be successfully used in screening new genotypes with efficient water and carbon use and in quantification of threshold of deleterious environmental effect to photosynthesis.

  8. A Prospective, Multicenter Study of Complementary/Alternative Medicine (CAM) Utilization During Definitive Radiation for Breast Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Moran, Meena S., E-mail: meena.moran@yale.edu [Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut (United States); Department of Radiation Therapy, William W. Backus Hospital, Norwich, Connecticut (United States); Ma Shuangge [Department of Epidemiology and Public Health, Yale University, New Haven, Connecticut (United States); Jagsi, Reshma [University of Michigan, Department of Radiation Oncology, Ann Arbor, MI (United States); Yang, Tzu-I Jonathan [Yale University School of Medicine, New Haven, Connecticut (United States); Higgins, Susan A. [Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut (United States); Department of Radiation Therapy, Shoreline Medical Center, Guilford, Connecticut (United States); Weidhaas, Joanne B. [Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut (United States); Wilson, Lynn D. [Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut (United States); Department of Radiation Therapy, Lawrence and Memorial Hospital, New London, Connecticut (United States); Lloyd, Shane [Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut (United States); Peschel, Richard [Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut (United States); Department of Radiation Therapy, Lawrence and Memorial Hospital, New London, Connecticut (United States); Gaudreau, Bryant [Department of Radiation Therapy, William W. Backus Hospital, Norwich, Connecticut (United States); Rockwell, Sara [Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut (United States)

    2013-01-01

    Purpose: Although complementary and alternative medicine (CAM) utilization in breast cancer patients is reported to be high, there are few data on CAM practices in breast patients specifically during radiation. This prospective, multi-institutional study was conducted to define CAM utilization in breast cancer during definitive radiation. Materials/Methods: A validated CAM instrument with a self-skin assessment was administered to 360 Stage 0-III breast cancer patients from 5 centers during the last week of radiation. All data were analyzed to detect significant differences between users/nonusers. Results: CAM usage was reported in 54% of the study cohort (n=194/360). Of CAM users, 71% reported activity-based CAM (eg, Reiki, meditation), 26% topical CAM, and 45% oral CAM. Only 16% received advice/counseling from naturopathic/homeopathic/medical professionals before initiating CAM. CAM use significantly correlated with higher education level (P<.001), inversely correlated with concomitant hormone/radiation therapy use (P=.010), with a trend toward greater use in younger patients (P=.066). On multivariate analysis, level of education (OR: 6.821, 95% CI: 2.307-20.168, P<.001) and hormones/radiation therapy (OR: 0.573, 95% CI: 0.347-0.949, P=.031) independently predicted for CAM use. Significantly lower skin toxicity scores were reported in CAM users vs nonusers, respectively (mild: 34% vs 25%, severe: 17% vs 29%, P=.017). Conclusion: This is the first prospective study to assess CAM practices in breast patients during radiation, with definition of these practices as the first step for future investigation of CAM/radiation interactions. These results should alert radiation oncologists that a large percentage of breast cancer patients use CAM during radiation without disclosure or consideration for potential interactions, and should encourage increased awareness, communication, and documentation of CAM practices in patients undergoing radiation treatment for breast

  9. Preparation and Preliminary Application of MAdCAM-1 Polyclonal Antibody in Dairy Cows with Subclinical Mastitis.

    Science.gov (United States)

    Xu, Chuang; Chen, Yuanyuan; Chang, Qiaocheng; Xia, Cheng; Yang, Wei; Zhang, Hongyou

    2015-08-01

    MAdCAM-1 plays an important role in mediating immune response and inflammation. This study aimed to express and purify a fusion protein of MAdCAM-1 in prokaryotic cells and to prepare rat anti-bovine MAdCAM-1 polyclonal antibodies. Prokaryotic expression vector pGEX-4T-1-MAdCAM-1 and pET-28a-MAdCAM-1 were constructed, respectively. The above plasmids were transformed into BL21 Escherichia coli strain. These recombinant strains were induced by IPTG and identified by Western blot analysis and SDS-PAGE. Wistar rats were immunized with recombinant protein (pET-28a-MAdCAM-1) emulsified with Freund's adjuvant, and antibody titers were measured by indirect ELISA. Antibody titers reached the highest value (1:128,000) after the third immunization. Western blot showed that rat anti-bovine MAdCAM-1 polyclonal antibody can not only recognize recombinant MAdCAM-1 protein expressed in E. coli but also recognizes natural MAdCAM-1 protein extracted from bovine tissues. However, commercial anti-mouse MAdCAM-1 monoclonal antibodies did not recognize the recombinant MAdCAM-1 protein or natural protein, which indicated no cross-reactivity between bovine MAdCAM-1 and mouse MAdCAM-1. Real-time fluorescence quantitative polymerase chain reaction and Western blot analysis showed that MAdCAM-1 expression was limited in mammary lymphoid nodes of subclinical mastitis in dairy cows. We speculate that MAdCAM-1 expression is inconsistent in different periods of the dairy cows. The successful preparation of rat anti-bovine MAdCAM-1 polyclonal antibody and its preliminary application in dairy cows provide the foundation for further study of the mechanism of anti-inflammation of MAdCAM-1 in dairy cows with subclinical mastitis. PMID:26301930

  10. A Prospective, Multicenter Study of Complementary/Alternative Medicine (CAM) Utilization During Definitive Radiation for Breast Cancer

    International Nuclear Information System (INIS)

    Purpose: Although complementary and alternative medicine (CAM) utilization in breast cancer patients is reported to be high, there are few data on CAM practices in breast patients specifically during radiation. This prospective, multi-institutional study was conducted to define CAM utilization in breast cancer during definitive radiation. Materials/Methods: A validated CAM instrument with a self-skin assessment was administered to 360 Stage 0-III breast cancer patients from 5 centers during the last week of radiation. All data were analyzed to detect significant differences between users/nonusers. Results: CAM usage was reported in 54% of the study cohort (n=194/360). Of CAM users, 71% reported activity-based CAM (eg, Reiki, meditation), 26% topical CAM, and 45% oral CAM. Only 16% received advice/counseling from naturopathic/homeopathic/medical professionals before initiating CAM. CAM use significantly correlated with higher education level (P<.001), inversely correlated with concomitant hormone/radiation therapy use (P=.010), with a trend toward greater use in younger patients (P=.066). On multivariate analysis, level of education (OR: 6.821, 95% CI: 2.307-20.168, P<.001) and hormones/radiation therapy (OR: 0.573, 95% CI: 0.347-0.949, P=.031) independently predicted for CAM use. Significantly lower skin toxicity scores were reported in CAM users vs nonusers, respectively (mild: 34% vs 25%, severe: 17% vs 29%, P=.017). Conclusion: This is the first prospective study to assess CAM practices in breast patients during radiation, with definition of these practices as the first step for future investigation of CAM/radiation interactions. These results should alert radiation oncologists that a large percentage of breast cancer patients use CAM during radiation without disclosure or consideration for potential interactions, and should encourage increased awareness, communication, and documentation of CAM practices in patients undergoing radiation treatment for breast

  11. Cadmium stress in wheat seedlings: growth, cadmium accumulation and photosynthesis

    DEFF Research Database (Denmark)

    Ci, Dunwei; Jiang, Dong; Wollenweber, Bernd;

    2010-01-01

    parameters were generally depressed by Cd stress, especially under the high Cd concentrations. Cd concentration and accumulation in both shoots and roots increased with increasing external Cd concentrations. Relationships between corrected parameters of growth, photosynthesis and fluorescence and corrected...... Cd concentrations in shoots and roots could be explained by the regression model Y = K/(1 + exp(a + bX)). Jing 411 was found to be Cd tolerant considering parameters of chlorophyll content, photosynthesis and chlorophyll fluorescence in which less Cd translocation was from roots into shoots. The high...

  12. CAD/CAM/HSM CAXAME of piston rods die%CAXAME-连杆模具的CAD/CAM/HSM

    Institute of Scientific and Technical Information of China (English)

    刘颖

    2005-01-01

    针对传统连杆模具制造工艺的不足,提出CAD/CAM/HSM加工技术的完整解决方案.首先使用CAXAME2004的造型功能进行三维实体造型,然后用CAXAME2004的加工功能生成数控加工程序,最后在HSM一600型高速铣削加工中心上完成整个加工过程.

  13. Aplikace CAD/CAM softwaru EdgeCAM při obrábění

    OpenAIRE

    Trčka, Vojtěch

    2010-01-01

    Bakalářská práce obsahuje souhrn informací o CAD/CAM softwaru Edgecam, nastavení post procesoru pro použití na výrobní stroj ZPS VMC 1060 s řídicím systémem DynaPath Delta MU Control 50. Popis jednotlivých výrobních strategií, řezných nástrojů, experimentální ověření CNC kódu na výrobním zařízení.

  14. CARBON DIOXIDE MITIGATION THROUGH CONTROLLED PHOTOSYNTHESIS; FINAL

    International Nuclear Information System (INIS)

    This research was undertaken to meet the need for a robust portfolio of carbon management options to ensure continued use of coal in electrical power generation. In response to this need, the Ohio Coal Research Center at Ohio University developed a novel technique to control the emissions of CO(sub 2) from fossil-fired power plants by growing organisms capable of converting CO(sub 2) to complex sugars through the process of photosynthesis. Once harvested, the organisms could be used in the production of fertilizer, as a biomass fuel, or fermented to produce alcohols. In this work, a mesophilic organism, Nostoc 86-3, was examined with respect to the use of thermophilic algae to recycle CO(sub 2) from scrubbed stack gases. The organisms were grown on stationary surfaces to facilitate algal stability and promote light distribution. The testing done throughout the year examined properties of CO(sub 2) concentration, temperature, light intensity, and light duration on process viability and the growth of the Nostoc. The results indicate that the Nostoc species is suitable only in a temperature range below 125 F, which may be practical given flue gas cooling. Further, results indicate that high lighting levels are not suitable for this organism, as bleaching occurs and growth rates are inhibited. Similarly, the organisms do not respond well to extended lighting durations, requiring a significant (greater than eight hour) dark cycle on a consistent basis. Other results indicate a relative insensitivity to CO(sub 2) levels between 7-12% and CO levels as high as 800 ppm. Other significant results alluded to previously, relate to the development of the overall process. Two processes developed during the year offer tremendous potential to enhance process viability. First, integration of solar collection and distribution technology from Oak Ridge laboratories could provide a significant space savings and enhanced use of solar energy. Second, the use of translating slug flow

  15. CARBON DIOXIDE MITIGATION THROUGH CONTROLLED PHOTOSYNTHESIS

    Energy Technology Data Exchange (ETDEWEB)

    Unknown

    2000-10-01

    This research was undertaken to meet the need for a robust portfolio of carbon management options to ensure continued use of coal in electrical power generation. In response to this need, the Ohio Coal Research Center at Ohio University developed a novel technique to control the emissions of CO{sub 2} from fossil-fired power plants by growing organisms capable of converting CO{sub 2} to complex sugars through the process of photosynthesis. Once harvested, the organisms could be used in the production of fertilizer, as a biomass fuel, or fermented to produce alcohols. In this work, a mesophilic organism, Nostoc 86-3, was examined with respect to the use of thermophilic algae to recycle CO{sub 2} from scrubbed stack gases. The organisms were grown on stationary surfaces to facilitate algal stability and promote light distribution. The testing done throughout the year examined properties of CO{sub 2} concentration, temperature, light intensity, and light duration on process viability and the growth of the Nostoc. The results indicate that the Nostoc species is suitable only in a temperature range below 125 F, which may be practical given flue gas cooling. Further, results indicate that high lighting levels are not suitable for this organism, as bleaching occurs and growth rates are inhibited. Similarly, the organisms do not respond well to extended lighting durations, requiring a significant (greater than eight hour) dark cycle on a consistent basis. Other results indicate a relative insensitivity to CO{sub 2} levels between 7-12% and CO levels as high as 800 ppm. Other significant results alluded to previously, relate to the development of the overall process. Two processes developed during the year offer tremendous potential to enhance process viability. First, integration of solar collection and distribution technology from Oak Ridge laboratories could provide a significant space savings and enhanced use of solar energy. Second, the use of translating slug flow

  16. Radiation transport analysis with the aid of CAD/CAM

    International Nuclear Information System (INIS)

    The determination of radiation exposure to sensitive parts in spacecraft involves complex shielding configurations and multi-directional exposures. Ray tracing is commonly used to determine shielding along different directions for transport calculations and dose conversions. Ray tracing requires geometric modeling of the spacecraft, structures, equipment and enclosures. Modeling by manual procedures is inefficient and slow. Combinatorial geometry codes are a substantial improvement over manual procedures but modeling a spacecraft and its contents can take many man months; and still involves many approximations. The increasing use of CAD/CAM in engineering and design results in the convenient accessibility of geometric modeling data. A CAD/CAM system, CADAM, was used to develop an ancillary program which provides one-dimensional ray trace information from CADAM models. The resultant ray trace information is used in subsequent transport analysis on a DEC computer. The result is a timesavings of man-months, by utilizing an existing data base and an increase in accuracy by using up-to-date geometrical information

  17. Characterization and performance of hyper Suprime-Cam CCD

    Science.gov (United States)

    Kamata, Yukiko; Miyazaki, Satoshi; Nakaya, Hidehiko; Suzuki, Hisanori; Miyazaki, Yasuhito; Muramatsu, Masaharu

    2010-07-01

    Hyper Suprime-Cam (HSC) is a second-generation wide field imaging camera for Subaru telescope with 10 times wider field of view (FOV) compared with Suprime-Cam (SC) currently being used. HSC makes the survey speed considerably faster than SC, while maintaining the high image quality of SC. The 1.5 degrees in diameter FOV is covered with 116 of 2K × 4K fully depleted back-illuminated CCDs with 15 μm pixels developed by HAMAMATSU Photonics K. K. and National Astronomical Observatory of Japan (NAOJ). The CCDs for HSC are designed to have higher quantum efficiency than those for SC in a wider range in the visible wavelengths, especially in the blue region. We at NAOJ have started acceptance inspection of the CCDs being delivered from HAMAMATSU. We used the X-ray source of 55Fe and the LED to measure charge transfer efficiency, readout noise, linearity, and full-well capacity of 33 CCDs. In addition, we measured the quantum efficiency of 7 CCDs. We confirmed all the CCDs have good performances and quality. In this paper, we report the results from the acceptance inspection and characterization of these CCDs.

  18. Rational redesign of the biodegradative enzyme cytochrome P450 cam:

    International Nuclear Information System (INIS)

    Cytochromes P450, a superfamily of monooxygenase enzymes present in all kingdoms of living organisms, are very versatile with respect to substrate range and catalytic functionality. Many recalcitrant halogenated hydrocarbons, on DOE sites and throughout the nation, result in serious environmental impact. Cytochromes P450 have been shown to be catalytically capable of, at least partial, dehalogenation of some such compounds. Clearly, however, their active site stereochemistry and related functional components are not well suited for this role because the rates of dehalogenation are generally rather modest. The evolution of modified active site and access channel structures may proceed very slowly if multiple genetic changes are simultaneously required for enzyme adaptation. Since each mutational event is by itself a rare event, a basic premise of our research is that designing multiple changes into an enzyme may be more timely than waiting for them to occur biologically either via natural selection or under laboratory-controlled conditions. Starting with available high-resolution x-ray crystal structures, molecular modeling and molecular dynamics simulations have been used to probe the basic structure/function principles and conformational fluctuations of the biodegradative enzyme, cytochrome P450cam (camphor hydroxylase from Pseudomonas putida) and active site mutants, to provide the fundamental understanding necessary for rational engineering of the enzyme for modified substrate specificity. In the present paper, we review our progress to data, in the area of molecular dynamics simulations and active site redesign of P450cam. 36 refs., 2 figs

  19. A submersible magnetic stirrer for use in measuring photosynthesis in a biofloc technology production system

    Science.gov (United States)

    Measuring photosynthesis or primary productivity in biofloc technology production systems is challenging because the biofloc must be maintained in suspension constantly. Photosynthesis can be measured in external incubators designed to keep the biofloc suspended in the biochemical oxygen demand (BOD...

  20. Application of microbial photosynthesis to energy production and CO2 fixation

    International Nuclear Information System (INIS)

    This paper presents different applications of microbial photosynthesis for energy production and carbon dioxide fixation. The authors discuss about energetic aspects of photosynthesis and features of biological way for solar energy conversion. (TEC). 4 figs., 12 refs

  1. The ExoMars PanCam Instrument

    Science.gov (United States)

    Griffiths, Andrew; Coates, Andrew; Muller, Jan-Peter; Jaumann, Ralf; Josset, Jean-Luc; Paar, Gerhard; Barnes, David

    2010-05-01

    The ExoMars mission has evolved into a joint European-US mission to deliver a trace gas orbiter and a pair of rovers to Mars in 2016 and 2018 respectively. The European rover will carry the Pasteur exobiology payload including the 1.56 kg Panoramic Camera. PanCam will provide multispectral stereo images with 34 deg horizontal field-of-view (580 microrad/pixel) Wide-Angle Cameras (WAC) and (83 microrad/pixel) colour monoscopic "zoom" images with 5 deg horizontal field-of-view High Resolution Camera (HRC). The stereo Wide Angle Cameras (WAC) are based on Beagle 2 Stereo Camera System heritage [1]. Integrated with the WACs and HRC into the PanCam optical bench (which helps the instrument meet its planetary protection requirements) is the PanCam interface unit (PIU); which provides image storage, a Spacewire interface to the rover and DC-DC power conversion. The Panoramic Camera instrument is designed to fulfil the digital terrain mapping requirements of the mission [2] as well as providing multispectral geological imaging, colour and stereo panoramic images and solar images for water vapour abundance and dust optical depth measurements. The High Resolution Camera (HRC) can be used for high resolution imaging of interesting targets detected in the WAC panoramas and of inaccessible locations on crater or valley walls. Additionally HRC will be used to observe retrieved subsurface samples before ingestion into the rest of the Pasteur payload. In short, PanCam provides the overview and context for the ExoMars experiment locations, required to enable the exobiology aims of the mission. In addition to these baseline capabilities further enhancements are possible to PanCam to enhance it's effectiveness for astrobiology and planetary exploration: 1. Rover Inspection Mirror (RIM) 2. Organics Detection by Fluorescence Excitation (ODFE) LEDs [3-6] 3. UVIS broadband UV Flux and Opacity Determination (UVFOD) photodiode This paper will discuss the scientific objectives and resource

  2. Bidirectional modulation of endogenous EpCAM expression to unravel its function in ovarian cancer

    NARCIS (Netherlands)

    van der Gun, B. T. F.; Huisman, C.; Stolzenburg, S.; Kazemier, H. G.; Ruiters, M. H. J.; Blancafort, P.; Rots, M. G.

    2013-01-01

    Background: The epithelial cell adhesion molecule (EpCAM) is overexpressed on most carcinomas. Dependent on the tumour type, its overexpression is either associated with improved or worse patient survival. For ovarian cancer, however, the role of EpCAM remains unclear. Methods: Cell survival of ovar

  3. Comparative fracture strength analysis of Lava and Digident CAD/CAM zirconia ceramic crowns

    Science.gov (United States)

    Kwon, Taek-Ka; Pak, Hyun-Soon; Han, Jung-Suk; Lee, Jai-Bong; Kim, Sung-Hun

    2013-01-01

    PURPOSE All-ceramic crowns are subject to fracture during function. To minimize this common clinical complication, zirconium oxide has been used as the framework for all-ceramic crowns. The aim of this study was to compare the fracture strengths of two computer-aided design/computer-aided manufacturing (CAD/CAM) zirconia crown systems: Lava and Digident. MATERIALS AND METHODS Twenty Lava CAD/CAM zirconia crowns and twenty Digident CAD/CAM zirconia crowns were fabricated. A metal die was also duplicated from the original prepared tooth for fracture testing. A universal testing machine was used to determine the fracture strength of the crowns. RESULTS The mean fracture strengths were as follows: 54.9 ± 15.6 N for the Lava CAD/CAM zirconia crowns and 87.0 ± 16.0 N for the Digident CAD/CAM zirconia crowns. The difference between the mean fracture strengths of the Lava and Digident crowns was statistically significant (P<.001). Lava CAD/CAM zirconia crowns showed a complete fracture of both the veneering porcelain and the core whereas the Digident CAD/CAM zirconia crowns showed fracture only of the veneering porcelain. CONCLUSION The fracture strengths of CAD/CAM zirconia crowns differ depending on the compatibility of the core material and the veneering porcelain. PMID:23755332

  4. Epidermal growth factor (EGF) sensitive phosphorylation of calmodulin (CAM) in A431 cell membrane

    International Nuclear Information System (INIS)

    A431, a transformed cell line, is known to contain a high concentration of EGF receptors (EGFR). Exogenous CAM, when combined with purified membrane from A431 is strongly phosphorylated in the presence of EGF. The EGF-dependent phosphorylation of CAM did not alter the normal profile of the A431 EGFR autophosphorylation, as demonstrated by SDS-PAGE and autoradiography. In addition to its EGF dependency, the presence of divalent cations is also critical for CAM phosphorylation. The presence of a divalent cation chelator, such as EGTA, caused a complete inhibition of CAM phosphorylation, which can be reversed with cations in the following order of effectiveness: Mg++ > Mn++ > Ca++. Divalent cations also break up CAM into four co-migrating bands as indicated by Coomassie Blue stained gels and the corresponding autoradiograms. Double antibody precipitation followed by phospho-amino acid analysis revealed that the EGF-sensitive CAM phosphorylation occurs exclusively on the serine residue. Using radioimmunoassay, purified A431 membrane was shown to contain a significant amount of endogenous CAM. The implications of the EGF-sensitive CAM phosphorylation are currently under investigation

  5. A new radiological index for assessing asphericity of the femoral head in cam impingement

    DEFF Research Database (Denmark)

    Gosvig, K K; Jacobsen, S; Palm, H; Sonne-Holm, S; Magnusson, E

    2007-01-01

    Femoroacetabular cam impingement is thought to be a cause of premature osteoarthritis of the hip. The presence of cam malformation was determined in 2803 standardised anteroposterior (AP) pelvic radiographs from the Copenhagen Osteoarthritis Study by measuring the alpha (alpha) angle and the tria...

  6. A new radiological index for assessing asphericity of the femoral head in cam impingement

    DEFF Research Database (Denmark)

    Gosvig, K K; Jacobsen, S; Palm, H;

    2007-01-01

    Femoroacetabular cam impingement is thought to be a cause of premature osteoarthritis of the hip. The presence of cam malformation was determined in 2803 standardised anteroposterior (AP) pelvic radiographs from the Copenhagen Osteoarthritis Study by measuring the alpha (alpha) angle and the...

  7. Cam deformity and hip degeneration are common after fixation of a slipped capital femoral epiphysis

    DEFF Research Database (Denmark)

    Klit, Jakob; Gosvig, Kasper; Magnussen, Erland;

    2014-01-01

    Background and purpose - Slipped capital femoral epiphysis is thought to result in cam deformity and femoroacetabular impingement. We examined: (1) cam-type deformity, (2) labral degeneration, chondrolabral damage, and osteoarthritic development, and (3) the clinical and patient-reported outcome...

  8. Some Aspects on Technological Design of a Cam Type Workpiece Using CATIA Software

    Directory of Open Access Journals (Sweden)

    Calin-Octavian Miclosina

    2013-09-01

    Full Text Available The paper presents the geometrical models of cam and of semi-finished piece, obtained with CATIA software. Two cam technological routes are shown and the optimal route is chosen. From the technological route, rough milling operation is simulated with CATIA software. By using different milling parameters, various machining time values are obtained.

  9. Spectroscopic observations of the RS CVn-type binary systems SV Cam and XY UMa

    International Nuclear Information System (INIS)

    Radial velocities of the primary components of the two RS CVn-type binary systems SV Cam and XY UMa are presented, for the first time for XY UMa. Neither secondary component could be detected. A change of 5.0±1.3km s-1 in the systemic velocity of SV Cam is found over 40 years which lends some support to the current model of SV Cam being a triple system. If the masses of the G3 V primary components of both systems are assumed to be one solar mass, then the secondaries are 0.7 (SV CAM) and 0.6 (XY UMa) solar masses; all four stars are main sequence objects with SV Cam being rather more evolved than XY UMa. (author)

  10. Optimal Design of a Cam Mechanism with Translating Flat-Face Follower using Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    I. Tsiafis

    2013-12-01

    Full Text Available The optimum design of a cam mechanism is a time consuming task, due to the numerous alternatives considerations. In the present work, the problem of design parameters optimization of a cam mechanism with translating flat - face follower is investigated from a multi - objective point of view. The design parameters, just like the cam base circle radius, the follower face width and the follower offset can be determined considering as the optimization criteria minimization of the cam size, of the input torque and of the contact stress. During the optimization procedure, a number of constraints regarding the pressure angle, the contact stress, etcare taken into account. The optimization approach, based on genetic algorithm, is applied to find the optimal solutions with respect to the a fore - mentioned objective function and to Ensure the kinematic requirements. Finally, the dynamic behavior of the designed cam mechanism is investigated considering the frictional forces.

  11. Bilgisayar destekli diş hekimliği ve güncel CAD/CAM sistemleri

    OpenAIRE

    Gözde Çelik; Tuğrul Sarı; Aslıhan Üşümez

    2013-01-01

    CAD/CAM systems (computer aided design/computer aided manufacturing) has been used in dentistry since 1987. In the past 25 years, development of various high quality chairside and laboratory CAD/CAM systems has been continued with the progress of technology. This article describes currently used CAD/CAM systems.

    Keywords: Dental, CAD/CAM systems.

     

    ÖZET

  12. Neural cell adhesion molecule (N-CAM) domains and intracellular signaling pathways involved in the inhibition of astrocyte proliferation

    OpenAIRE

    Krushel, Leslie A.; Tai, Ming-Hong; Cunningham, Bruce A.; Edelman, Gerald M.; Crossin, Kathryn L.

    1998-01-01

    The neural cell adhesion molecule (N-CAM) inhibits astrocyte proliferation in vitro and in vivo, and this effect is partially reversed by the glucocorticoid antagonist RU-486. The present studies have tested the hypothesis that N-CAM-mediated inhibition of astrocyte proliferation is caused by homophilic binding and involves the activation of glucocorticoid receptors. It was observed that all N-CAM Ig domains inhibited astrocyte proliferation in parallel with their ability to influence N-CAM b...

  13. Cam Deformity and Hip Degeneration Presents 10 to 17 Years After Fixation of a Slipped Capital Femoral Epiphysis

    DEFF Research Database (Denmark)

    Klit, Jakob; Gosvig, Kasper; Magnussen, Erland;

    2014-01-01

    Background and purpose: Slipped capital femoral epiphysis (SCFE) is hypothesized to result in cam deformity and femoroacetabular impingement. We examined: (1)cam-type deformity, (2) labral degeneration, chondrolabral damage, and osteoarthritic development, (3) the clinical and patient-reported ou......Background and purpose: Slipped capital femoral epiphysis (SCFE) is hypothesized to result in cam deformity and femoroacetabular impingement. We examined: (1)cam-type deformity, (2) labral degeneration, chondrolabral damage, and osteoarthritic development, (3) the clinical and patient...

  14. A scoping review of research on complementary and alternative medicine (CAM) and the mass media: Looking back, moving forward

    OpenAIRE

    Strudsholm Tina; Weeks Laura C

    2008-01-01

    Abstract Background The use of complementary and alternative medicine (CAM) has become more common in Western developed countries in recent years, as has media reporting on CAM and related issues. Correspondingly, media reports are a primary information source regarding decisions to use CAM. Research on CAM related media reports is becoming increasingly relevant and important; however, identifying key concepts to guide future research is problematic due to the dispersed nature of completed re...

  15. Measurement of Solar Spectra Relating to Photosynthesis and Solar Cells: An Inquiry Lab for Secondary Science

    Science.gov (United States)

    Ruggirello, Rachel M.; Balcerzak, Phyllis; May, Victoria L.; Blankenship, Robert E.

    2012-01-01

    The process of photosynthesis is central to science curriculum at all levels. This article describes an inquiry-based laboratory investigation developed to explore the impact of light quality on photosynthesis and to connect this process to current research on harvesting solar energy, including bioenergy, artificial photosynthesis, and solar…

  16. Identification and characterization of nuclear genes involved in photosynthesis in Populus

    OpenAIRE

    Wang, Bowen; Du, Qingzhang; Yang, Xiaohui; Zhang, Deqiang

    2014-01-01

    Background The gap between the real and potential photosynthetic rate under field conditions suggests that photosynthesis could potentially be improved. Nuclear genes provide possible targets for improving photosynthetic efficiency. Hence, genome-wide identification and characterization of the nuclear genes affecting photosynthetic traits in woody plants would provide key insights on genetic regulation of photosynthesis and identify candidate processes for improvement of photosynthesis. Resul...

  17. Overcoming Student Misconceptions about Photosynthesis: A Model- and Inquiry-Based Approach Using Aquatic Plants

    Science.gov (United States)

    Ray, Andrew M.; Beardsley, Paul M.

    2008-01-01

    Even though photosynthesis is an obligatory part of the science curriculum, research has shown that students often have a poor understanding of it. The authors advocate that classroom coverage of the topic of photosynthesis should include not only its biochemical properties but also the role of photosynthesis or photosynthetic organisms in matter…

  18. Aplikace CAD/CAM softwaru FeatureCAM při obrábění

    OpenAIRE

    Foltán, Petr

    2013-01-01

    Diplomová práce obsahuje vypracovaný postup výroby části kokily pro gravitační lití pístů s využitím softwaru FeatureCAM. Zabývá se výběrem vhodného strojního a nástrojového vybavení, určením řezných podmínek a řešením výběru optimálních strategií obrábění v softwaru FeatureCAM. Celý proces obrábění je ověřen grafickou simulací a je doplněn výkresovou dokumentací součásti.

  19. Bibliography of reviews and methods of photosynthesis - 88

    Czech Academy of Sciences Publication Activity Database

    Šesták, Zdeněk; Čatský, Jiří

    2004-01-01

    Roč. 42, č. 4 (2004), s. 619-640. ISSN 0300-3604 R&D Projects: GA ČR GA206/97/0120 Institutional research plan: CEZ:AV0Z5038910 Keywords : Bibliographic survey * processes of photosynthesis * accumulation of energy Subject RIV: EF - Botanics Impact factor: 0.734, year: 2004

  20. Photorespiration and Oxygen Inhibition of Photosynthesis in Chlorella pyrenoidosa.

    Science.gov (United States)

    Shelp, B J; Canvin, D T

    1980-05-01

    The inhibition of photosynthesis by O(2) in air-grown Chlorella pyrenoidosa was investigated using three experimental techniques (artificial leaf, aqueous method, and O(2) electrode) to measure carbon assimilation. CO(2) response curves were determined under different O(2), pH, and temperature conditions. Regardless of the experimental technique and condition, O(2) inhibition was not evident until a concentration of 50% was reached; V(max) values were reduced whereas K(m) (CO(2)) values were unaffected by the increasing O(2) concentration. The response of photosynthesis to O(2) was independent of CO(2) and HCO(3) (-) concentrations as well as temperature. Relative rates of photosynthesis showed a 4 to 5% stimulation in 2% O(2), a 12% inhibition in 50% O(2), and a 24% inhibition in 100% O(2). The inhibition by 50% O(2) was still reversible after 20 minutes exposure whereas 100% O(2) caused irreversible inhibition after only 4 minutes.The O(2) inhibition is discussed in terms of the oxygenase reaction and a Mehler reaction supporting pseudocyclic electron flow. The results are inconsistent with the proposals that photorespiration exists in these algae and that a CO(2)-concentrating mechanism suppresses the O(2) inhibition of photosynthesis. PMID:16661282

  1. ‘Direct Conversion’: Artificial Photosynthesis With Cyanobacteria

    NARCIS (Netherlands)

    Q. Chen; D. Montesarchio; K.J. Hellingwerf

    2016-01-01

    Cyanobacteria, the only bacteria that can carry out oxygenic, (ie, plant-type) photosynthesis, can be engineered with the methods of synthetic biology so that they acquire the ability to convert CO2 directly into biofuel and/or commodity chemicals. In such an approach one bypasses the formation of t

  2. Light dependence of carboxylation capacity for C3 photosynthesis models

    Science.gov (United States)

    Photosynthesis at high light is often modelled by assuming limitation by the maximum capacity of Rubisco carboxylation at low carbon dioxide concentrations, by electron transport capacity at higher concentrations, and sometimes by triose-phosphate utilization rate at the highest concentrations. Pho...

  3. PRELIMINARY PHOTOSYNTHESIS EXAMINATIONS OF THERMOFIL EVERGREEN ORNAMENTAL SHRUBS IN HUNGARY

    OpenAIRE

    MARÁCZI, Kata; Gáspár, László; BARACSI, Eva

    2012-01-01

    The purpose of this research was to determine the climatic- ecological demand of thermofil broadleaf evergreen ornamental shrubs. On three different habitats: in field conditions, in container and on hillside was investigated the fluorescence induction experiments with PAM-2000 chlorophyll-fluorimetry, which was used to measure the photosynthesis 2 quantum yield of the plant.

  4. Photosynthesis in Relation to Reproductive Success of Cypripedium flavum

    OpenAIRE

    ZHANG, SHIBAO; Hu, Hong; Zhou, Zhekun; Xu, Kun; YAN, NING; LI, SHUYUN

    2005-01-01

    • Background and Aims Cypripedium flavum is a rare, endemic alpine slipper orchid of China, which is under threat from excessive collection and habitat changes. Conservation and re-introduction of C. flavum is restricted by lack of knowledge of the plant's photosynthesis and how that affects reproductive success. The hypothesis is tested that reproductive success is determined by photosynthetic production.

  5. Iron is essential for photosynthesis and respiration : iron deficiency

    OpenAIRE

    HEUVELINK, E.; Kierkels, T.

    2016-01-01

    Iron plays a major role in photosynthesis. That’s why a shortage directly affects the production capacity of the plant. The application of chelates has made iron much more easy to absorb. Nevertheless it’s an element that we have to keep an eye on.

  6. Photosynthesis of Digitaria ciliaris during repeated soil drought and rewatering

    Institute of Scientific and Technical Information of China (English)

    YaYong Luo; XueYong Zhao; JingHui Zhang; YuLin Li; XiaoAn Zuo; DianChao Sun

    2015-01-01

    The ability of psammophyte photosynthesis to withstand and recover from severe droughts is crucial for vegetation sta-bility in semi-arid sandy lands. The responses of gas exchange and chlorophyll fluorescence of an annual grass, Digitaria ciliaris, were measured through three soil drought and rewatering cycles. Results showed that the net photosynthesis rate (Pn) decreased by 92%, 95%, and 63%at end of the three drought periods, respectively, water use efficiency (WUE) de-creased by 67%, 54%, and 48%, while the constant intercellular CO2 concentration (Ci) increased by 1.08, 0.88, and 0.45 times. During those three cycles, the trapping probability with no dark adaptation (Fv′/Fm′) decreased by 55%, 51%, and 9%, the electron transport per cross section (ET0′/CS0′) decreased by 63%, 42%, and 18%, and the dissipation per cross section (DI0′/CS0′) increased by 97%, 96%, and 21%. These results indicated that D. ciliaris was subjected to photoinhi-bition and some non-stomatal limitation of photosynthesis under drought. However, after four days of rewatering, its photosynthetic characteristics were restored to control values. This capability to recover from drought may contribute to making the plant's use of water as efficient as possible. Furthermore, the photosynthesis decreased more slowly in the subsequent drought cycles than in the first cycle, allowing D. ciliaris to enhance its future drought tolerance after drought hardening. Thus, it acclimatizes itself to repeated soil drought.

  7. Photosynthesis in Plants with Non-Green Leaves

    Science.gov (United States)

    Vartak, Rehka

    2006-01-01

    Enquiry based learning is an important tool in science teaching. Students of Class XI (16-17 years old) were asked to hypothesise on the role of different pigments found in plants with non-green leaves. The majority hypothesised that these plants were devoid of chlorophylls and some other pigments performed the function of photosynthesis. Their…

  8. Future Elementary School Teachers' Conceptual Change Concerning Photosynthesis

    Science.gov (United States)

    Ahopelto, Ilona; Mikkila-Erdmann, Mirjamaija; Anto, Erkki; Penttinen, Marjaana

    2011-01-01

    The purpose of this study was to examine conceptual change among future elementary school teachers while studying a scientific text concerning photosynthesis. Students' learning goals in relation to their learning outcomes were also examined. The participants were future elementary school teachers. The design consisted of pre- and post-tests. The…

  9. Connecting Photosynthesis and Cellular Respiration: Preservice Teachers' Conceptions

    Science.gov (United States)

    Brown, Mary H.; Schwartz, Renee S.

    2009-01-01

    The biological processes of photosynthesis and plant cellular respiration include multiple biochemical steps, occur simultaneously within plant cells, and share common molecular components. Yet, learners often compartmentalize functions and specialization of cell organelles relevant to these two processes, without considering the interconnections…

  10. Plants and Photosynthesis: Peer Assessment to Help Students Learn

    Science.gov (United States)

    Crane, Lucy; Winterbottom, Mark

    2008-01-01

    This study investigates how peer assessment can help students to learn about photosynthesis in a "high attaining," year nine class in a UK 11-18 comprehensive school. There is limited research on how peer assessment can influence the learning of "high attaining students"; most existing research focuses on how formative assessment can benefit…

  11. Photoinduced electron transfer in model systems of photosynthesis.

    NARCIS (Netherlands)

    Hofstra, U.

    1988-01-01

    This Thesis describes Investigations on photoinduced electron transfer (ET) for several compounds, serving as model systems of the natural photosynthesis. In addition, the properties of the systems, e.g. the conformation in solution and the electronic properties of the photoexcited states are treate

  12. Effector Roles of Putidaredoxin on Cytochrome P450cam Conformational States.

    Science.gov (United States)

    Liou, Shu-Hao; Mahomed, Mavish; Lee, Young-Tae; Goodin, David B

    2016-08-17

    In this study, the effector role of Pdx (putidaredoxin) on cytochrome P450cam conformation is refined by attaching two different spin labels, MTSL or BSL (bifunctional spin-label) onto the F or G helices and using DEER (double electron-electron resonance) to measure the distance between labels. Recent EPR and crystallographic studies have observed that oxidized Pdx induces substrate-bound P450cam to change from the closed to the open state. However, this change was not observed by DEER in the reduced Pdx complex with carbon-monoxide-bound P450cam (Fe(2+)CO). In addition, recent NMR studies have failed to observe a change in P450cam conformation upon binding Pdx. Hence, resolving these issues is important for a full understanding the effector role of Pdx. Here we show that oxidized Pdx induces camphor-bound P450cam to shift from the closed to the open conformation when labeled on either the F or G helices with MTSL. BSL at these sites can either narrow the distance distribution widths dramatically or alter the extent of the conformational change. In addition, we report DEER spectra on a mixed oxidation state containing oxidized Pdx and ferrous CO-bound P450cam, showing that P450cam remains closed. This indicates that CO binding to the heme prevents P450cam from opening, overriding the influence exerted by Pdx binding. Finally, we report the open form P450cam crystal structure with substrate bound, which suggests that crystal packing effects may prevent conformational conversion. Using multiple labeling approaches, DEER provides a unique perspective to resolve how the conformation of P450cam depends on Pdx and ligand states. PMID:27452076

  13. CAM use in pediatric neurology: an exploration of concurrent use with conventional medicine.

    Directory of Open Access Journals (Sweden)

    Elaine Galicia-Connolly

    Full Text Available BACKGROUND: Previous studies have found that up to 60% of children with neurologic conditions have tried complementary and alternative medicine (CAM. OBJECTIVE: To assess the use of CAM among patients presenting to neurology clinics at two academic centers in Canada. METHODS: A survey instrument was developed to inquire about use of CAM products and therapies, including reasons for use, perceived helpfulness, and concurrent use with conventional medicine, and administered to patients or their parents/guardians at the Stollery Children's Hospital in Edmonton and the Children's Hospital of Eastern Ontario (CHEO in Ottawa. RESULTS: Overall CAM use at the Stollery was 78%, compared to 48% at CHEO. The most common CAM products used were multi-vitamins (84%, vitamin C (37%, homeopathic remedies (24%, and fish oil/omega 3 s (22%. The most common CAM practices used were massage (47%, chiropractic (37%, faith healing (18%, aromatherapy (16%, homeopathy (16%, and relaxation (16%. Many patients used CAM products at the same time as conventional medicine but just over half (57% discussed this concurrent use with their physician. CONCLUSION: CAM use is common in pediatric neurology patients and most respondents felt that it was helpful, with few or no harms associated. However, this use is often undisclosed, increasing possibility of interactions with conventional drugs. We urge clinicians to inquire about CAM use during routine history taking at every patient visit. Parents would clearly like more information about CAM from their specialty clinics; such information would be easier to share if more primary data were available about the safety and effectiveness of commonly used therapies.

  14. C4 Photosynthesis (The CO2-Concentrating Mechanism and Photorespiration).

    Science.gov (United States)

    Dai, Z.; Ku, MSB.; Edwards, G. E.

    1993-09-01

    Despite previous reports of no apparent photorespiration in C4 plants based on measurements of gas exchange under 2 versus 21% O2 at varying [CO2], photosynthesis in maize (Zea mays) shows a dual response to varying [O2]. The maximum rate of photosynthesis in maize is dependent on O2 (approximately 10%). This O2 dependence is not related to stomatal conductance, because measurements were made at constant intercellular CO2 concentration (Ci); it may be linked to respiration or pseudocyclic electron flow. At a given Ci, increasing [O2] above 10% inhibits both the rate of photosynthesis, measured under high light, and the maximum quantum yield, measured under limiting light ([phi]CO2). The dual effect of O2 is masked if measurements are made under only 2 versus 21% O2. The inhibition of both photosynthesis and [phi]CO2 by O2 (measured above 10% O2) with decreasing Ci increases in a very similar manner, characteristically of O2 inhibition due to photorespiration. There is a sharp increase in O2 inhibition when the Ci decreases below 50 [mu]bar of CO2. Also, increasing temperature, which favors photorespiration, causes a decrease in [phi]CO2 under limiting CO2 and 40% O2. By comparing the degree of inhibition of photosynthesis in maize with that in the C3 species wheat (Triticum aestivum) at varying Ci, the effectiveness of C4 photosynthesis in concentrating CO2 in the leaf was evaluated. Under high light, 30[deg]C, and atmospheric levels of CO2 (340 [mu]bar), where there is little inhibition of photosynthesis in maize by O2, the estimated level of CO2 around ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) in the bundle sheath compartment was 900 [mu]bar, which is about 3 times higher than the value around Rubisco in mesophyll cells of wheat. A high [CO2] is maintained in the bundle sheath compartment in maize until Ci decreases below approximately 100 [mu]bar. The results from these gas exchange measurements indicate that photorespiration occurs in maize but

  15. 2009 Photosynthesis to be held June 28 - July 3, 2009

    Energy Technology Data Exchange (ETDEWEB)

    Doug Bruce

    2009-07-06

    The capture of solar energy by photosynthesis has had a most profound influence on the development and sustenance of life on earth. It is the engine that has driven the proliferation of life and, as the source of both energy and oxygen, has had a major hand in shaping the forms that life has taken. Both ancient and present day photosynthetic carbon fixation is intimately tied to issues of immediate human concern, global energy and global warming. Decreasing our reliance on fossil fuels by tapping photosynthesis in a more direct way is an attractive goal for sustainable energy. Meeting this challenge means understanding photosynthetic energy conversion at a molecular level, a task requiring perspectives ranging through all disciplines of science. Researchers in photosynthesis have a strong history of working across conventional boundaries and engaging in multidisciplinary collaborations. The Gordon conference in photosynthesis has been a key focal point for the dissemination of new results and the establishment of powerful research collaborations. In this spirit the 2009 Gordon conference on biophysical aspects of photosynthesis will bring together top international researchers from diverse and complementary disciplines, all working towards understanding how photosynthesis converts light into the stable chemical energy that powers so much of our world. Focal points for talks and discussions will include: (1) Watersplitting, structure and function of the oxygen evolving complex; (2) Antenna, the diversity, optimization and regulation of energy capture and transfer; (3) Reaction center structure and function, including functional roles for the protein; (4) Electron transport, proton transport and energy coupling; (5) Photoprotection mechanisms, including secondary electron transport pathways; (6) Biofuels, hydrogen production; and (7) Artificial photosynthesis and solar energy conversion strategies. The 2009 conference will have a close eye on practical applications

  16. Prevalence and Predictors of Complementary and Alternative Medicine (CAM) Use among Ivy League College Students: Implications for Student Health Services

    Science.gov (United States)

    Versnik Nowak, Amy L.; DeGise, Joe; Daugherty, Amanda; O'Keefe, Richard; Seward, Samuel, Jr.; Setty, Suma; Tang, Fanny

    2015-01-01

    Objective: Determine prevalence and types of complementary and alternative medicine (CAM) therapies used and test the significance of demographics and social cognitive constructs as predictors of CAM use in a college sample. Secondary purpose was to guide the integration of CAM therapies into college health services. Participants: Random,…

  17. Scale dependence in the effects of leaf ecophysiological traits on photosynthesis: Bayesian parameterization of photosynthesis models.

    Science.gov (United States)

    Feng, Xiaohui; Dietze, Michael

    2013-12-01

    Relationships between leaf traits and carbon assimilation rates are commonly used to predict primary productivity at scales from the leaf to the globe. We addressed how the shape and magnitude of these relationships vary across temporal, spatial and taxonomic scales to improve estimates of carbon dynamics. Photosynthetic CO2 and light response curves, leaf nitrogen (N), chlorophyll (Chl) concentration and specific leaf area (SLA) of 25 grassland species were measured. In addition, C3 and C4 photosynthesis models were parameterized using a novel hierarchical Bayesian approach to quantify the effects of leaf traits on photosynthetic capacity and parameters at different scales. The effects of plant physiological traits on photosynthetic capacity and parameters varied among species, plant functional types and taxonomic scales. Relationships in the grassland biome were significantly different from the global average. Within-species variability in photosynthetic parameters through the growing season could be attributed to the seasonal changes of leaf traits, especially leaf N and Chl, but these responses followed qualitatively different relationships from the across-species relationship. The results suggest that one broad-scale relationship is not sufficient to characterize ecosystem condition and change at multiple scales. Applying trait relationships without articulating the scales may cause substantial carbon flux estimation errors. PMID:23952643

  18. Photosynthesis Activates Plasma Membrane H+-ATPase via Sugar Accumulation.

    Science.gov (United States)

    Okumura, Masaki; Inoue, Shin-Ichiro; Kuwata, Keiko; Kinoshita, Toshinori

    2016-05-01

    Plant plasma membrane H(+)-ATPase acts as a primary transporter via proton pumping and regulates diverse physiological responses by controlling secondary solute transport, pH homeostasis, and membrane potential. Phosphorylation of the penultimate threonine and the subsequent binding of 14-3-3 proteins in the carboxyl terminus of the enzyme are required for H(+)-ATPase activation. We showed previously that photosynthesis induces phosphorylation of the penultimate threonine in the nonvascular bryophyte Marchantia polymorpha However, (1) whether this response is conserved in vascular plants and (2) the process by which photosynthesis regulates H(+)-ATPase phosphorylation at the plasma membrane remain unresolved issues. Here, we report that photosynthesis induced the phosphorylation and activation of H(+)-ATPase in Arabidopsis (Arabidopsis thaliana) leaves via sugar accumulation. Light reversibly phosphorylated leaf H(+)-ATPase, and this process was inhibited by pharmacological and genetic suppression of photosynthesis. Immunohistochemical and biochemical analyses indicated that light-induced phosphorylation of H(+)-ATPase occurred autonomously in mesophyll cells. We also show that the phosphorylation status of H(+)-ATPase and photosynthetic sugar accumulation in leaves were positively correlated and that sugar treatment promoted phosphorylation. Furthermore, light-induced phosphorylation of H(+)-ATPase was strongly suppressed in a double mutant defective in ADP-glucose pyrophosphorylase and triose phosphate/phosphate translocator (adg1-1 tpt-2); these mutations strongly inhibited endogenous sugar accumulation. Overall, we show that photosynthesis activated H(+)-ATPase via sugar production in the mesophyll cells of vascular plants. Our work provides new insight into signaling from chloroplasts to the plasma membrane ion transport mechanism. PMID:27016447

  19. Academic doctors' views of complementary and alternative medicine (CAM and its role within the NHS: an exploratory qualitative study

    Directory of Open Access Journals (Sweden)

    Shaw Alison

    2007-05-01

    Full Text Available Abstract Background There has been a marked increase in the use of complementary and alternative medicine (CAM in the UK population in recent years. Surveys of doctors' perspectives on CAM have identified a variety of views and potential information needs. While these are useful for describing the proportions of doctors who hold particular attitudes towards CAM, they are less helpful for understanding why. In addition, while the views of non-academic doctors have begun to be studied, the perspective and rationales of academic doctors remains under-researched. It seems important to investigate the views of those with a research-orientation, given the emphasis on the need for more scientific evidence in recent debates on CAM. Methods This exploratory study used qualitative methods to explore academic doctors' views of CAM and the rationales they provided for their views. A purposeful sampling strategy was used to identify doctors with a dual clinical and academic role in the Bristol area, with an anticipated variety of views on CAM. Semi-structured interviews were conducted with nine doctors. The data were analysed thematically, drawing on the Framework Approach. Results The doctors expressed a spectrum of views on CAM, falling into three broad groups: the 'enthusiasts', the 'sceptics' and the 'undecided'. Scepticism or uncertainty about the value of CAM was prominent, except among those practising a form of CAM. A variety of rationales underpinned their perspectives on CAM, a key recurring rationale being their perspective on the scientific evidence base. The main themes arising included: the role of doctors' professional experiences of conventional medicine and CAM in shaping their attitudes towards CAM, doctor-patient communication about CAM and patient disclosure, whether there is a need for training and education in CAM for doctors, a hierarchy of acceptability of CAM and the nature of evidence; and the role of CAM within the NHS. Conclusion

  20. Paper-Less CAD/CAM For Accelerator Components

    Energy Technology Data Exchange (ETDEWEB)

    Franks, R M; Alford, O; Bertolini, L R

    2001-01-12

    Computer-aided design and manufacture (CAD/CAM) have enabled advances in the design and manufacture of many accelerator components, though government procurement rules tend to inhibit its use. We developed and executed a method that provides adequate documentation for the procurement process, industrial vendor manufacturing processes, and laboratory installation activities. We detail our experiences in the design and manufacture of 60 separate and unique PEP-II Low Energy Ring Interaction Region vacuum chambers totaling {approx} 140m in length as an example of how we used this technique, reducing design effort and manufacturing risk while streamlining the production process. We provide ''lessons learned'' to better implement and execute the process in subsequent iterations. We present our study to determine the estimated savings in the design and production of the Spallation Neutron Source room temperature linac if this process were utilized.

  1. Intelligent gateway processors as integrators of CAD/CAM networks

    Energy Technology Data Exchange (ETDEWEB)

    Hampel, V.E.; Garner, B.L.; Matthews, J.R.

    1985-07-01

    The integration of dissimilar CAD/CAM hardware and software on local and geographically distributed networks is the major problem faced by large organizations today. We begin by examining the existing system for storage, retrieval, control, and distribution of design information at Lawrence Livermore National Laboratory (LLNL) and describe a new prototype Engineering Information System (EIS). We then discuss the Department of Energy neutral Data Exchange Format (DOE/DEF) for the sharing of mechanical drawings among DOE installations. Finally, we describe the potential role of the Intelligent Gateway Processor (IGP) as a transaction controller for engineering resources among contractors of the Air Force Logistics Command (AFLC). IGP capabilities include a unique interpreter-driven user interface which permits the installation and modification of resources and the translation of dissimilar data formats, commands, and protocols, in a unified manner while running non-stop.

  2. Model-Based Engineering and Manufacturing CAD/CAM Benchmark

    Energy Technology Data Exchange (ETDEWEB)

    Domm, T.D.; Underwood, R.S.

    1999-04-26

    than a single computer-aided manufacturing (CAM) system. The Inteznet was a technology that all companies were considering to either transport information more easily throughout the corporation or as a conduit for business, as the small firm was doing Successfully. Because PrdEngineer is the de facto CAD standard fbr the NWC, the Benchmark Team targeted companies using Parametric Technology Corporation (PTC) software tools. Most of the companies used Pm'Engineer for design to some degree, but found the PTC CAM product, PdManufacture lacking as compared to alternate CAM solutions. All of the companies visited fOund the data exchange between CAD/CAM systems problematic. It was apparent that these companies were trying to consolidate their software tools to reduce translation but had not been able to do so because no single solution had all the needed capabilities. In regard to organizational slructure and human resoukes, two companies were found to be using product or program teams. These teams consisted of the technical staff capable of completing the entire task and were xmintained throughout the project. This same strategy was evident at another of the companies but with more mobility of members. For all eornpanies visited except the small ~ work structure breakdown and responsibility were essentially the same as Y-12's at this time. The functions of numerical control (NC), desi~ and process planning were separate and distinct. The team made numerous recommendations that are detailed in the report.

  3. A CAD/CAM system for operating overburden conveyor bridges

    Energy Technology Data Exchange (ETDEWEB)

    Pause, M.; Nadeborn, H.; Klus, R.

    1988-01-01

    Reviews introduction of computer systems for control of conveyor bridges for overburden removal in GDR brown coal surface mines. Three F 60 high capacity bridges at Welzow, Nochten and Jaenschwalde have been automated since 1978, achieving a 10% increase in annual production. A pilot project of complex automation of a F 45 brige at the Meuro mine was started to fully automate bridge movement according to continuous mine geometrical digital survey data. Hardware employed is the U 5000 control system with various peripheral equipment, the A 5120 office computer and the EC 1040 data processing unit. Automation of the Meuro bridge resulted in an annual economic benefit of 2.8 million Marks. A new, fourth F 60 bridge for which a CAD/CAM system based on the U 5000 and K 1520 computer systems is being developed will begin operation at the Reichwalde mine.

  4. Paper-Less CAD/CAM For Accelerator Components

    International Nuclear Information System (INIS)

    Computer-aided design and manufacture (CAD/CAM) have enabled advances in the design and manufacture of many accelerator components, though government procurement rules tend to inhibit its use. We developed and executed a method that provides adequate documentation for the procurement process, industrial vendor manufacturing processes, and laboratory installation activities. We detail our experiences in the design and manufacture of 60 separate and unique PEP-II Low Energy Ring Interaction Region vacuum chambers totaling ∼ 140m in length as an example of how we used this technique, reducing design effort and manufacturing risk while streamlining the production process. We provide ''lessons learned'' to better implement and execute the process in subsequent iterations. We present our study to determine the estimated savings in the design and production of the Spallation Neutron Source room temperature linac if this process were utilized

  5. Off-line programming: key to CAD/CAM (robots)

    Energy Technology Data Exchange (ETDEWEB)

    Durham, T.

    1983-06-23

    Off-line programming is essential if robots are to be fully integrated into the computer-aided design/computer-aided manufacturing (CAD/CAM) process. It is also fundamental to the use of robots with touch and vision sensors, since the movements of such a robot depend on real-world data and cannot be taught in advance. Edinburgh (UK) University's Department of Artificial Intelligence is developing a high-level language called Rapt, for the programming of assembly robots. Rapt is described as an object-level language. Its statements refer to material objects and their physical relationships and motions. It uses higher level descriptions than those of commercially available robot languages such as unimation's val. The developments in off-line programming which are crucial to the successful integration of industrial robots into computer-aided design and manufacturing processes are discussed.

  6. Hyper Suprime-Cam: filter exchange unit and shutter

    Science.gov (United States)

    Uraguchi, Fumihiro; Wang, Shiang-Yu; Komiyama, Yutaka; Liaw, Eric J. Y.; Chiu, Chi-Fang; Chen, Hsin-Yo; Ho, Cheng-Lin; Lai, Tsang-Chih; Lee, Yao-Cheng; Jeng, Dun-Zen; Iwamura, Satoru; Kamata, Yukiko; Kawanomoto, Satoshi; Miyazaki, Satoshi; Morokuma, Tomoki; Nakaya, Hidehiko; Utsumi, Yousuke

    2012-09-01

    We have developed a filter exchange unit (FEU) and a shutter of Hyper Suprime-Cam (HSC). FEU consists of two parts; the alignment mechanism of the filter in the optical path and a jukebox of the filters. The alignment mechanism can guarantee 10 μm position stability with respect to the focal plane CCDs. On the exchange sequence, a motorized cart grabs and pushes the filter from the jukebox. Each jukebox has 3 slots and we have two identical jukeboxes. The operation is fully automated and the entire exchange sequence takes 16 minutes. Also, we developed the focal-plane shutter with 1,030 mm diameter envelope and 60 mm thickness while having 600 mm aperture. We report the detail of design and implementation of the shutter and FEU, and installation procedure of FEU.

  7. Chemical composition of umbu (Spondias tuberosa Arr. Cam seeds

    Directory of Open Access Journals (Sweden)

    Soraia Vilela Borges

    2007-02-01

    Full Text Available The umbu tree (Spondias tuberosa Arr. Cam is an important fruit tree the economy of the semi-arid northeastern region of Brazil. With the objective of finding use for the seeds, physical and chemical characterizations of the seeds from 2 cultivars in 2 maturation stages were carried out and their fatty acid and mineral profiles determined. The results showed no differences between the seeds analyzed. The yield was about 10% and the dimensions as follows: length from 1.48 to 2.11 cm and width from 0.76 to 1.16 cm. The average lipid content was 55% of which 69% was unsaturated and the average protein content was 24%. The seeds were a good source of the following minerals: P, K, Mg, Fe and Cu. The overall results indicated that the oil or the seeds could be used for food stuffs if no toxic agents were found.

  8. Model-Based Engineering and Manufacturing CAD/CAM Benchmark

    International Nuclear Information System (INIS)

    than a single computer-aided manufacturing (CAM) system. The Inteznet was a technology that all companies were considering to either transport information more easily throughout the corporation or as a conduit for business, as the small firm was doing Successfully. Because PrdEngineer is the de facto CAD standard fbr the NWC, the Benchmark Team targeted companies using Parametric Technology Corporation (PTC) software tools. Most of the companies used Pm'Engineer for design to some degree, but found the PTC CAM product, PdManufacture lacking as compared to alternate CAM solutions. All of the companies visited found the data exchange between CAD/CAM systems problematic. It was apparent that these companies were trying to consolidate their software tools to reduce translation but had not been able to do so because no single solution had all the needed capabilities. In regard to organizational structure and human resources, two companies were found to be using product or program teams. These teams consisted of the technical staff capable of completing the entire task and were xmintained throughout the project. This same strategy was evident at another of the companies but with more mobility of members. For all companies visited except the small work structure breakdown and responsibility were essentially the same as Y-12's at this time. The functions of numerical control (NC), desi and process planning were separate and distinct. The team made numerous recommendations that are detailed in the report

  9. Marginal Integrity of CAD/CAM Fixed Partial Dentures

    Science.gov (United States)

    Rosentritt, Martin; Behr, Michael; Kolbeck, Carola; Handel, Gerhard

    2007-01-01

    Objectives Computer-aided design (CAD) and manufacturing (CAM) allows the milling of high strength zirconia fixed partial dentures (FPD), however bonding to an inert ZrO2 ceramic surface may effect the marginal integrity of the FPDs. The aim of this investigation was to evaluate the marginal adaptation of zirconia FPDs at the interfaces between zirconia, cement, and tooth. Methods 32 3-unit FPDs were fabricated of the CAD/CAM Y-TZP zirconia (Lava, 3M Espe, Germany) according to the manufacturers’ instructions. Resin cements with corresponding primer and bonding systems were used to lute the FPDs: Compolute/EBS multi (3M Espe, Germany), Panavia F/ED (Kuraray, Japan), Variolink 2/Syntac classic (Ivoclar-Vivadent, FL) and RelyX Unicem/without treatment (3M Espe, Germany). Aualloy FPDs (BioPontostar, Bego, Germany) were cemented with RelyX Unicem and Harvard (Harvard, Germany) as the control. Marginal adaptation was evaluated with scanning electron microscopy using replica specimen before and after artificial aging. After aging, microleakage tests were performed with fuchsine solution. The interfaces between cement-tooth and cement-FPD were examined. Results At the interfaces (cement-tooth and cement-FPD), the systems showed a 95% or higher perfect margin before and after aging. Only Variolink2/Syntac had a marginal adaptation, lower than a 70% perfect margin. Generally, the fuchsine penetration was below 20%, only BioPontstar/Harvard andLava/Variolink2 showed penetration results between 80% and 100%. Conclusion The success of the adhesive cementation of zirconia FPDs depends on the cement system. Under the conditions of this study, zirconia FPDs showed good to sufficient marginal integrity in combination with Panavia/ED, Compolute/EBS and RelyX Unicem. PMID:19212494

  10. Standardizing PhenoCam Image Processing and Data Products

    Science.gov (United States)

    Milliman, T. E.; Richardson, A. D.; Klosterman, S.; Gray, J. M.; Hufkens, K.; Aubrecht, D.; Chen, M.; Friedl, M. A.

    2014-12-01

    The PhenoCam Network (http://phenocam.unh.edu) contains an archive of imagery from digital webcams to be used for scientific studies of phenological processes of vegetation. The image archive continues to grow and currently has over 4.8 million images representing 850 site-years of data. Time series of broadband reflectance (e.g., red, green, blue, infrared bands) and derivative vegetation indices (e.g. green chromatic coordinate or GCC) are calculated for regions of interest (ROI) within each image series. These time series form the basis for subsequent analysis, such as spring and autumn transition date extraction (using curvature analysis techniques) and modeling the climate-phenology relationship. Processing is relatively straightforward but time consuming, with some sites having more than 100,000 images available. While the PhenoCam Network distributes the original image data, it is our goal to provide higher-level vegetation phenology products, generated in a standardized way, to encourage use of the data without the need to download and analyze individual images. We describe here the details of the standard image processing procedures, and also provide a description of the products that will be available for download. Products currently in development include an "all-image" file, which contains a statistical summary of the red, green and blue bands over the pixels in predefined ROI's for each image from a site. This product is used to generate 1-day and 3-day temporal aggregates with 90th percentile values of GCC for the specified time-periodwith standard image selection/filtering criteria applied. Sample software (in python, R, MATLAB) that can be used to read in and plot these products will also be described.

  11. The electronic counting arm movement test (eCAM test).

    Science.gov (United States)

    Bodranghien, Florian; Martin, Claire; Ansay, Caroline; Camut, Stephane; Busegnies, Yves; Manto, Mario

    2015-06-01

    A novel transportable electronic platform aiming to characterize the performance of successive fast vertical visually guided pointing movements toward two fixed targets (eCAM test: electronic counting arm movement test) is described and one validation test is presented. This platform is based on an Arduino(®) micro-controller and a Processing(®) routine. It records both the pointing performance (number of clicks) and the elapsed time between two successive pointing movements. Using this novel platform, we studied the effects of functional electrical stimulation (FES) applied on the dominant upper limb in 15 healthy volunteers (mean age ± SD: 22.3 ± 4.3 years; 5 males/10 females). The following muscles were stimulated: flexor carpi radialis (FCR), extensor carpi radialis (ECR), biceps brachii (BB), and triceps brachii (TB). The intensities of the stimulation were 2 and 3 mA above the sensory threshold (ST). Movement times were lesser when performed against gravity and pointing performance improved with FES. We provide the first demonstration that low-intensity FES impacts on motor performances during successive vertical goal-directed pointing movements under visual guidance. The eCAM test is currently the sole electronic tool to assess quickly and easily the performances of successive vertical pointing movements. Future potential applications include, in particular, the follow-up of the effects of neurorehabilitation of neurological/neurosurgical disorders associated with hand-eye incoordination, the functional evaluation of upper limb prosthesis or orthosis, and the analysis of the effects of FES in central or peripheral nervous system disorders. PMID:25413688

  12. Design of Cylindrical Cam with Oscillating Follower Based on 3D Expansion of Planar Profile Model

    Institute of Scientific and Technical Information of China (English)

    CHEN Junhua; LIN Zuan; WU Yijie

    2009-01-01

    Cylindrical cam with oscillating follower is widely applicable and used in many mechanical devices and machines. However, a common error exists in the methods of designing planar profile for oscillating follower cylinder cam. In this study, we propose a new hypothesis to solve this design problem with the inclusion of deviation angle. On the basis of this new concept, equations for planar profile expansion and methods of calculating pressure angle are deduced by applying 3D expansion formula of the follower's motion orbit. When the pressure angle is less than allowable value, the minimum base radius can be determined by using MATLAB software. Accordingly, the planar profile of oscillating follower cylinder cam is generated by CAD software. This new method is practical and can be easily adopted for the design of oscillating follower cylindrical cam with desirable accuracy. We applied the method in the design of cylindrical cam for paper feeding mechanism used in high-speed printers. We calculated the planar profile and used it to direct the NC machine for the manufacture of the groove of cylindrical cam. The improved cylindrical cam met all of the requirements of speed and accuracy demanded by high-speed printers. Therefore, our new method has been validated by practical application.

  13. Effect of degradative plasmid CAM-OCT on responses of Pseudomonas bacteria to UV light

    International Nuclear Information System (INIS)

    The effect of plasmid CAM-OCT on responses to UV irradiation was compared in Pseudomonas aeruginosa, in Pseudomonas putida, and in Pseudomonas putida mutants carrying mutations in UV response genes. CAM-OCT substantially increased both survival and mutagenesis in the two species. P. aeruginosa strains without CAM-OCT exhibited much higher UV sensitivity than did P. putida strains. UV-induced mutagenesis of plasmid-free P. putida was easily detected in three different assays (two reversion assays and one forward mutation assay), whereas UV mutagenesis of P. aeruginosa without CAM-OCT was seen only in the forward mutation assay. These results suggest major differences in DNA repair between the two species and highlight the presence of error-prone repair functions on CAM-OCT. A number of P. putida mutants carrying chromosomal mutations affecting either survival or mutagenesis after UV irradiation were isolated, and the effect of CAM-OCT on these mutants was determined. All mutations producing a UV-sensitive phenotype in P. putida were fully suppressed by the plasmid, whereas the plasmid had a more variable effect on mutagenesis mutations, suppressing some and producing no suppression of others. On the basis of the results reported here and results obtained by others with plasmids carrying UV response genes, it appears that CAM-OCT may differ either in regulation or in the number and functions of UV response genes encoded

  14. Comparative evaluation of RetCam vs. gonioscopy images in congenital glaucoma

    Directory of Open Access Journals (Sweden)

    Raj V Azad

    2014-01-01

    Full Text Available Purpose: To compare clarity, exposure and quality of anterior chamber angle visualization in congenital glaucoma patients, using RetCam and indirect gonioscopy images. Design: Cross-sectional study Participants. Congenital glaucoma patients over age of 5 years. Materials and Methods: A prospective consecutive pilot study was done in congenital glaucoma patients who were older than 5 years. Methods used are indirect gonioscopy and RetCam imaging. Clarity of the image, extent of angle visible and details of angle structures seen were graded for both methods, on digitally recorded images, in each eye, by two masked observers. Outcome Measures: Image clarity, interobserver agreement. Results: 40 eyes of 25 congenital glaucoma patients were studied. RetCam image had excellent clarity in 77.5% of patients versus 47.5% by gonioscopy. The extent of angle seen was similar by both methods. Agreement between RetCam and gonioscopy images regarding details of angle structures was 72.50% by observer 1 and 65.00% by observer 2. Conclusions: There was good agreement between RetCam and indirect gonioscopy images in detecting angle structures of congenital glaucoma patients. However, RetCam provided greater clarity, with better quality, and higher magnification images. RetCam can be a useful alternative to gonioscopy in infants and small children without the need for general anesthesia.

  15. Functional analysis of the domains of the C elegans Ror receptor tyrosine kinase CAM-1.

    Science.gov (United States)

    Kim, Changsung; Forrester, Wayne C

    2003-12-15

    cam-1 encodes a Caenorhabditis elegans orphan receptor tyrosine kinase (RTK) of the Ror family that is required for cell migration and to orient cell polarity. Ror RTKs share a common domain structure. The predicted extracellular region contains immunoglobulin (Ig), cysteine-rich (CRD), and kringle (Kri) domains. Intracellularly are tyrosine kinase (Kin) and serine- and threonine (S/T)-rich domains. To investigate the functional requirement for CAM-1 domains in mediating cell migration, we engineered deletions that remove various domains and assessed the ability of these CAM-1 derivatives to rescue cam-1 mutant phenotypes. We find that the Ig, Kri, Kin, and S/T domains are dispensable for cell migration, but the CRD is required. Surprisingly, the entire intracellular region of CAM-1 is not required for proper cell migration. Most notably, a version of CAM-1 from which all domains besides the CRD and transmembrane domains have been deleted is able to rescue the migration of a single cell type, although not those of other cell types. Our results show that CAM-1 does not function exclusively as a canonical RTK and that it may function, at least in part, to regulate the distribution of a secreted ligand-possibly a Wnt protein. PMID:14651925

  16. COMPLEMENTARY AND ALTERNATIVE MEDICINE (CAM THERAPIES FOR MANAGEMENT OF PAIN RELATED TO ENDOMETRIOSIS

    Directory of Open Access Journals (Sweden)

    Panda Roshni

    2012-03-01

    Full Text Available Endometriosis is a gynaecological disease with a complex etiology. It is associated with severe pelvic pain, sub fertility and reduced quality of life. Endometriosis has a multifactorial etiology and therefore its management is also multidimensional. The main targets of therapy are controlling of the pain symptoms and increasing fertility where it is desired. Hormonal and surgical therapies are the two major treatment modalities available currently. But they are not without their side effects. Therefore many women explore Complementary and Alternative Medicine (CAM forms of treatment for symptomatic relief from pain. These CAM therapies have been used as an adjuvant to conventional therapy or as an independent form of treatment. CAM therapies are purported to have lesser side effects as compared to conventional medical formulations. Ancient Chinese and Indian medicine system have laid the foundation of several of the prevalent Cam practices. The following CAM practices have been discussed in the article-Acupuncture, Herbal therapy, Meditation and Hypnotherapy, Yoga, Exercise, Dietary therapy Aromatherapy and Massage, Reiki, Magnet therapy and Chiropractice. Randomized Clinical Trials (RCT have been conducted for some of the CAM therapies in Endometriosis and Acupuncture and Herbal and Dietary therapies have been found to have some positive effect on the patients. The efficacy of CAM therapies still needs substantial evidence to be integrated into general healthcare practices.

  17. Role of L1CAM in the Regulation of the Canonical Wnt Pathway and Class I MAGE Genes.

    Science.gov (United States)

    Shkurnikov, M Yu; Knyazev, E N; Wicklein, D; Schumacher, U; Samatov, T R; Tonevitskii, A G

    2016-04-01

    Molecule L1CAM is specific for nerve cells and tumors of various localizations. The expression of L1CAM is significantly higher in melanoma in comparison with benign nevi and correlates with the progress of melanoma and transition from radial to vertical growth. Monoclonal antibodies to L1CAM effectively and specifically attenuate melanoma growth, though stimulates the epithelial-mesenchymal transition. shRNA-mediated knock-down of L1CAM showed the involvement of L1CAM in regulation of activity of the canonical Wnt pathway and expression of genes of class I melanoma-associated antigens (MAGE). PMID:27165065

  18. Regulated intramembrane proteolysis and degradation of murine epithelial cell adhesion molecule mEpCAM.

    Directory of Open Access Journals (Sweden)

    Matthias Hachmeister

    Full Text Available Epithelial cell adhesion molecule EpCAM is a transmembrane glycoprotein, which is highly and frequently expressed in carcinomas and (cancer-stem cells, and which plays an important role in the regulation of stem cell pluripotency. We show here that murine EpCAM (mEpCAM is subject to regulated intramembrane proteolysis in various cells including embryonic stem cells and teratocarcinomas. As shown with ectopically expressed EpCAM variants, cleavages occur at α-, β-, γ-, and ε-sites to generate soluble ectodomains, soluble Aβ-like-, and intracellular fragments termed mEpEX, mEp-β, and mEpICD, respectively. Proteolytic sites in the extracellular part of mEpCAM were mapped using mass spectrometry and represent cleavages at the α- and β-sites by metalloproteases and the b-secretase BACE1, respectively. Resulting C-terminal fragments (CTF are further processed to soluble Aβ-like fragments mEp-β and cytoplasmic mEpICD variants by the g-secretase complex. Noteworthy, cytoplasmic mEpICD fragments were subject to efficient degradation in a proteasome-dependent manner. In addition the γ-secretase complex dependent cleavage of EpCAM CTF liberates different EpICDs with different stabilities towards proteasomal degradation. Generation of CTF and EpICD fragments and the degradation of hEpICD via the proteasome were similarly demonstrated for the human EpCAM ortholog. Additional EpCAM orthologs have been unequivocally identified in silico in 52 species. Sequence comparisons across species disclosed highest homology of BACE1 cleavage sites and in presenilin-dependent γ-cleavage sites, whereas strongest heterogeneity was observed in metalloprotease cleavage sites. In summary, EpCAM is a highly conserved protein present in fishes, amphibians, reptiles, birds, marsupials, and placental mammals, and is subject to shedding, γ-secretase-dependent regulated intramembrane proteolysis, and proteasome-mediated degradation.

  19. Initial activation of EpCAM cleavage via cell-to-cell contact

    International Nuclear Information System (INIS)

    Epithelial cell adhesion molecule EpCAM is a transmembrane glycoprotein, which is frequently over-expressed in simple epithelia, progenitors, embryonic and tissue stem cells, carcinoma and cancer-initiating cells. Besides functioning as a homophilic adhesion protein, EpCAM is an oncogenic receptor that requires regulated intramembrane proteolysis for activation of its signal transduction capacity. Upon cleavage, the extracellular domain EpEX is released as a soluble ligand while the intracellular domain EpICD translocates into the cytoplasm and eventually into the nucleus in combination with four-and-a-half LIM domains protein 2 (FHL2) and β-catenin, and drives cell proliferation. EpCAM cleavage, induction of the target genes, and transmission of proliferation signals were investigated under varying density conditions using confocal laser scanning microscopy, immunoblotting, cell counting, and conditional cell systems. EpCAM cleavage, induction of the target genes, and transmission of proliferation signals were dependent on adequate cell-to-cell contact. If cell-to-cell contact was prohibited EpCAM did not provide growth advantages. If cells were allowed to undergo contact to each other, EpCAM transmitted proliferation signals based on signal transduction-related cleavage processes. Accordingly, the pre-cleaved version EpICD was not dependent on cell-to-cell contact in order to induce c-myc and cell proliferation, but necessitated nuclear translocation. For the case of contact-inhibited cells, although cleavage of EpCAM occurred, nuclear translocation of EpICD was reduced, as were EpCAM effects. Activation of EpCAM's cleavage and oncogenic capacity is dependent on cellular interaction (juxtacrine) to provide for initial signals of regulated intramembrane proteolysis, which then support signalling via soluble EpEX (paracrine)

  20. Strength of CAD/CAM-generated esthetic ceramic molar implant crowns

    OpenAIRE

    Wolf, D; Bindl, A; Schmidlin, P R; Lüthy, H; Mörmann, W H

    2008-01-01

    PURPOSE: One-visit in-office CAD/CAM fabrication of esthetic ceramic crowns as a superstructure for posterior implants is quite new. The aim of the study was to evaluate the strength of esthetic ceramic CAD/CAM crowns with varied occlusal thickness and seated with adhesive and nonadhesive cements on titanium and zirconia abutments. MATERIALS AND METHODS: Esthetic ceramic CAD/CAM-generated molar crowns (n = 15 per group) with occlusal thicknesses of 0.5 mm and 1.5 mm were seated on titanium (1...

  1. Comparative fracture strength analysis of Lava and Digident CAD/CAM zirconia ceramic crowns

    OpenAIRE

    Kwon, Taek-Ka; Pak, Hyun-Soon; Yang, Jae-Ho; Han, Jung-Suk; Lee, Jai-Bong; Kim, Sung-Hun; Yeo, In-Sung

    2013-01-01

    PURPOSE All-ceramic crowns are subject to fracture during function. To minimize this common clinical complication, zirconium oxide has been used as the framework for all-ceramic crowns. The aim of this study was to compare the fracture strengths of two computer-aided design/computer-aided manufacturing (CAD/CAM) zirconia crown systems: Lava and Digident. MATERIALS AND METHODS Twenty Lava CAD/CAM zirconia crowns and twenty Digident CAD/CAM zirconia crowns were fabricated. A metal die was also ...

  2. Process Chain in Automotive Industry - Present Day Demands versus Long Term Open CAD/CAM Strategies

    OpenAIRE

    Dankwort, C. Werner

    1997-01-01

    The automotive industry was a pioneer in using CAD/CAM technology. Now the car manufacturers development process is almost completely done with this technology. Substantial initiative for the standardisation of CAD/CAM technics comes from the automotive industry, as e.g. for neutral CAD data interfaces. The R&D departments of German car manufacturers have founded a working group ii with the aim to develop a common long term CAD/CAM strategy. One important result is the concept of a future CAx...

  3. Marginal and internal fit of nano-composite CAD/CAM restorations

    OpenAIRE

    Park, So-Hyun; Yoo, Yeon-Jee; Shin, Yoo-Jin; Cho, Byeong-Hoon; Baek, Seung-Ho

    2016-01-01

    Objectives The purpose of this study was to compare the marginal and internal fit of nano-composite CAD-CAM restorations. Materials and Methods A full veneer crown and an mesio-occluso-distal (MOD) inlay cavity, which were prepared on extracted human molars, were used as templates of epoxy resin replicas. The prepared teeth were scanned and CAD-CAM restorations were milled using Lava Ultimate (LU) and experimental nano-composite CAD/CAM blocks (EB) under the same milling parameters. To assess...

  4. Coupling the Community Atmospheric Model (CAM) with the Statistical Spectral Interpolation (SSI) System under ESMF

    Science.gov (United States)

    daSilva, Arlindo

    2004-01-01

    The first set of interoperability experiments illustrates the role ESMF can play in integrating the national Earth science resources. Using existing data assimilation technology from NCEP and the National Weather Service, the Community Atmosphere Model (CAM) was able to ingest conventional and remotely sensed observations, a capability that could open the door to using CAM for weather as well as climate prediction. CAM, which includes land surface capabilities, was developed by NCAR, with key components from GSFC. In this talk we will describe the steps necessary for achieving the coupling of these two systems.

  5. DYNAMIC ANALYSIS OF A CRIMPING DEVICE WITH MULTIPLE CAMS USING MSC ADAMS II

    Directory of Open Access Journals (Sweden)

    Gheorghe Popescu

    2012-05-01

    Full Text Available Through the present paper, the author presents the results of the dynamic analysis with MSC ADAMS of the mechanism with a crimping device with 12 tightening cams, designed and used in the technological process of assembly of the indigenous electrical detonators. In this sense, the mechanism with multiple cams is considered a mechanical system and is treated as an assembly of rigid bodies connected by mechanical connections and elastic elements. For shaping and simulation of the mechanism with multiple cams using ADAMS program, the author got through the following stages: construction of the pattern, its testing and simulation, validation, finishing, parametrization, optimization of the pattern.

  6. L1CAM protein expression is associated with poor prognosis in non-small cell lung cancer

    Directory of Open Access Journals (Sweden)

    Weder Walter

    2011-10-01

    Full Text Available Abstract Background The L1 cell adhesion molecule (L1CAM is potentially involved in epithelial-mesenchymal transition (EMT. EMT marker expression is of prognostic significance in non-small cell lung cancer (NSCLC. The relevance of L1CAM for NSCLC is unclear. We investigated the protein expression of L1CAM in a cohort of NSCLC patients. L1CAM protein expression was correlated with clinico-pathological parameters including survival and markers of epithelial-mesenchymal transition. Results L1CAM protein expression was found in 25% of squamous cell carcinomas and 24% of adenocarcinomas and correlated with blood vessel invasion and metastasis (p Conclusions A subset of NSCLCs with vessel tropism and increased metastasis aberrantly expresses L1CAM. L1CAM is a novel prognostic marker for NSCLCs that is upregulated by EMT induction and appears to be instrumental for enhanced cell invasion.

  7. Evolution of Photosynthesis and Biospheric Oxygenation Contingent Upon Nitrogen Fixation?

    CERN Document Server

    Grula, J W

    2006-01-01

    How photosynthesis by Precambrian cyanobacteria oxygenated Earth's biosphere remains incompletely understood. Here it is argued that the oxic transition, which took place between approximately 2.3 and 0.5 Gyr ago, required a great proliferation of cyanobacteria, and this in turn depended on their ability to fix nitrogen via the nitrogenase enzyme system. However, the ability to fix nitrogen was not a panacea, and the rate of biospheric oxygenation may still have been affected by nitrogen constraints on cyanobacterial expansion. Evidence is presented for why cyanobacteria probably have a great need for fixed nitrogen than other prokaryotes, underscoring the importance of their ability to fix nitrogen. The connection between nitrogen fixation and the evolution of photosynthesis is demonstrated by the similarities between nitrogenase and enzymes critical for the biosynthesis of (bacterio)chlorophyll. It is hypothesized that biospheric oxygenation would not have occurred if the emergence of cyanobacteria had not ...

  8. Anthocyanin-dependent anoxygenic photosynthesis in coloured flower petals?

    Science.gov (United States)

    Lysenko, Vladimir; Varduny, Tatyana

    2013-11-01

    Chlorophylless flower petals are known to be composed of non-photosynthetic tissues. Here, we show that the light energy storage that can be photoacoustically measured in flower petals of Petunia hybrida is approximately 10-12%. We found that the supposed chlorophylless photosynthesis is an anoxygenic, anthocyanin-dependent process occurring in blue flower petals (ADAPFP), accompanied by non-respiratory light-dependent oxygen uptake and a 1.5-fold photoinduced increase in ATP levels. Using a simple, adhesive tape stripping technique, we have obtained a backside image of an intact flower petal epidermis, revealing sword-shaped ingrowths connecting the cell wall and vacuole, which is of interest for the further study of possible vacuole-related photosynthesis. Approaches to the interpretations of ADAPFP are discussed, and we conclude that these results are not impossible in terms of the known photochemistry of anthocyanins.

  9. Spectral signatures of photosynthesis I: Review of Earth organisms

    CERN Document Server

    Kiang, N Y; Blankenship, R E; Kiang, Nancy Y.; Siefert, Janet; Blankenship, Robert E.

    2007-01-01

    Why do plants reflect in the green and have a 'red edge' in the red, and should extrasolar photosynthesis be the same? We provide: 1) a brief review of how photosynthesis works; 2) an overview of the diversity of photosynthetic organisms, their light harvesting systems, and environmental ranges; 3) a synthesis of photosynthetic surface spectral signatures; 4) evolutionary rationales for photosynthetic surface reflectance spectra with regard to utilization of photon energy and the planetary light environment. Given the surface incident photon flux density spectrum and resonance transfer in light harvesting, we propose some rules with regard to where photosynthetic pigments will peak in absorbance: a) the wavelength of peak incident photon flux; b) the longest available wavelength for core antenna or reaction center pigments; and c) the shortest wavelengths within an atmospheric window for accessory pigments. That plants absorb less green light may not be an inefficient legacy of evolutionary history, but may a...

  10. Photochemistry of porphyrins: a model for the origin of photosynthesis

    Science.gov (United States)

    Mercer-Smith, J. A.; Mauzerall, D. C.

    1984-01-01

    A series of porphyrins and catalysts has been prepared as a model for the origin of photosynthesis on the primordial earth. These compounds have been used to test the hypotheses that (1) the biosynthetic pathway to chlorophyll recapitulates the evolutionary history of photosynthesis, and (2) the proto-photosythetic function of biogenetic porphyrins (biosynthetic chlorophyll precursors) was the oxidation of organic molecules by photoexcited porphyrins with the attendant emission of molecular hydrogen. This paper describes experiments in which photoexcited biogenetic porphyrins oxidize ethylenediamine tetraacetic acid (EDTA). The concomitant reduction of protons to hydrogen gas occurs in the presence of a colloidal platinum catalyst. The addition of methyl viologen, a one-electron shuttle, increases the amount of molecular hydrogen generated during long irradiations and the quantum yield of hydrogen production. When the porphyrin and catalyst are held in association by molecular complexes, the increased efficiency of electron transfer produces higher yields of hydrogen gas.

  11. Ecosystem respiration depends strongly on photosynthesis in a temperate heath

    DEFF Research Database (Denmark)

    Larsen, Klaus Steenberg; Ibrom, Andreas; Beier, Claus;

    2007-01-01

    We measured net ecosystem CO2 flux (F-n) and ecosystem respiration (R-E), and estimated gross ecosystem photosynthesis (P-g) by difference, for two years in a temperate heath ecosystem using a chamber method. The exchange rates of carbon were high and of similar magnitude as for productive forest...... ecosystems with a net ecosystem carbon gain during the second year of 293 +/- 11 g C m(-2) year(-1) showing that the carbon sink strength of heather-dominated ecosystems may be considerable when C. vulgaris is in the building phase of its life cycle. The estimated gross ecosystem photosynthesis and ecosystem...... respiration from October to March was 22% and 30% of annual flux, respectively, suggesting that both cold-season carbon gain and loss were important in the annual carbon cycle of the ecosystem. Model fit of R-E of a classic, first-order exponential equation related to temperature ( second year; R-2 = 0...

  12. Photorespiration connects C3 and C4 photosynthesis.

    Science.gov (United States)

    Bräutigam, Andrea; Gowik, Udo

    2016-05-01

    C4 plants evolved independently more than 60 times from C3 ancestors. C4 photosynthesis is a complex trait and its evolution from the ancestral C3 photosynthetic pathway involved the modification of the leaf anatomy and the leaf physiology accompanied by changes in the expression of thousands of genes. Under high temperature, high light, and the current CO2 concentration in the atmosphere, the C4 pathway is more efficient than C3 photosynthesis because it increases the CO2 concentration around the major CO2 fixating enzyme Rubisco. The oxygenase reaction and, accordingly, photorespiration are largely suppressed. In the present review we describe a scenario for C4 evolution that not only includes the avoidance of photorespiration as the major driving force for C4 evolution but also highlights the relevance of changes in the expression of photorespiratory genes in inducing and establishing important phases on the path from C3 to C4. PMID:26912798

  13. Timescales of Oxygenation Following the Evolution of Oxygenic Photosynthesis

    Science.gov (United States)

    Ward, Lewis M.; Kirschvink, Joseph L.; Fischer, Woodward W.

    2016-03-01

    Among the most important bioenergetic innovations in the history of life was the invention of oxygenic photosynthesis—autotrophic growth by splitting water with sunlight—by Cyanobacteria. It is widely accepted that the invention of oxygenic photosynthesis ultimately resulted in the rise of oxygen by ca. 2.35 Gya, but it is debated whether this occurred more or less immediately as a proximal result of the evolution of oxygenic Cyanobacteria or whether they originated several hundred million to more than one billion years earlier in Earth history. The latter hypothesis involves a prolonged period during which oxygen production rates were insufficient to oxidize the atmosphere, potentially due to redox buffering by reduced species such as higher concentrations of ferrous iron in seawater. To examine the characteristic timescales for environmental oxygenation following the evolution of oxygenic photosynthesis, we applied a simple mathematical approach that captures many of the salient features of the major biogeochemical fluxes and reservoirs present in Archean and early Paleoproterozoic surface environments. Calculations illustrate that oxygenation would have overwhelmed redox buffers within ~100 kyr following the emergence of oxygenic photosynthesis, a geologically short amount of time unless rates of primary production were far lower than commonly expected. Fundamentally, this result arises because of the multiscale nature of the carbon and oxygen cycles: rates of gross primary production are orders of magnitude too fast for oxygen to be masked by Earth's geological buffers, and can only be effectively matched by respiration at non-negligible O2 concentrations. These results suggest that oxygenic photosynthesis arose shortly before the rise of oxygen, not hundreds of millions of years before it.

  14. Pectin Methylesterification Impacts the Relationship between Photosynthesis and Plant Growth.

    Science.gov (United States)

    M Weraduwage, Sarathi; Kim, Sang-Jin; Renna, Luciana; C Anozie, Fransisca; D Sharkey, Thomas; Brandizzi, Federica

    2016-06-01

    Photosynthesis occurs in mesophyll cells of specialized organs such as leaves. The rigid cell wall encapsulating photosynthetic cells controls the expansion and distribution of cells within photosynthetic tissues. The relationship between photosynthesis and plant growth is affected by leaf area. However, the underlying genetic mechanisms affecting carbon partitioning to different aspects of leaf growth are not known. To fill this gap, we analyzed Arabidopsis plants with altered levels of pectin methylesterification, which is known to modulate cell wall plasticity and plant growth. Pectin methylesterification levels were varied through manipulation of cotton Golgi-related (CGR) 2 or 3 genes encoding two functionally redundant pectin methyltransferases. Increased levels of methylesterification in a line over-expressing CGR2 (CGR2OX) resulted in highly expanded leaves with enhanced intercellular air spaces; reduced methylesterification in a mutant lacking both CGR-genes 2 and 3 (cgr2/3) resulted in thin but dense leaf mesophyll that limited CO2 diffusion to chloroplasts. Leaf, root, and plant dry weight were enhanced in CGR2OX but decreased in cgr2/3. Differences in growth between wild type and the CGR-mutants can be explained by carbon partitioning but not by variations in area-based photosynthesis. Therefore, photosynthesis drives growth through alterations in carbon partitioning to new leaf area growth and leaf mass per unit leaf area; however, CGR-mediated pectin methylesterification acts as a primary factor in this relationship through modulation of the expansion and positioning of the cells in leaves, which in turn drive carbon partitioning by generating dynamic carbon demands in leaf area growth and leaf mass per unit leaf area. PMID:27208234

  15. From leaf to tree: upscaling of artificial photosynthesis

    OpenAIRE

    Turan, Bugra; Becker, Jan-Philipp; Urbain, Felix; Finger, Friedhelm; Rau, Uwe; Haas, Stefan

    2016-01-01

    Energy storage becomes crucial for energy systems with an increasing share of renewable energy sources. Artificial photosynthesis, in particular photovoltaic water splitting, provides both sustainable energy generation and energy storage in the form of hydrogen. However, only a few concepts for scalable devices were reported in the literature. Here, we introduce a new concept which, by design, is scalable and compatible with every thin-film photovoltaic technology. The concept allows for inde...

  16. Photosynthesis in lightfleck areas of homobaric and heterobaric leaves

    OpenAIRE

    Pieruschka, R.; Chavarria-Krauser, A.; Schurr, U.; Jahnke, S.

    2009-01-01

    Leaves within a canopy are exposed to a spatially and temporally fluctuating light environment which may cause lateral gradients in leaf internal CO(2) concentration and diffusion between shaded and illuminated areas. In previous studies it was hypothesized that lateral CO(2) diffusion may support leaf photosynthesis, but the magnitude of this effect is still not well understood. In the present study homobaric leaves of Vicia faba or heterobaric leaves of Glycine max were illuminated with lig...

  17. Quantum coherence in photosynthesis for efficient solar-energy conversion

    OpenAIRE

    Romero, Elisabet; Augulis, Ramunas; Novoderezhkin, Vladimir I.; Ferretti, Marco; Thieme, Jos; Zigmantas, Donatas; van Grondelle, Rienk

    2014-01-01

    The crucial step in the conversion of solar to chemical energy in Photosynthesis takes place in the reaction center where the absorbed excitation energy is converted into a stable charge separated state by ultrafast electron transfer events. However, the fundamental mechanism responsible for the near unity quantum efficiency of this process is unknown. Here we elucidate the role of coherence in determining the efficiency of charge separation in the plant photosystem II reaction centre (PSII R...

  18. A perspective on underwater photosynthesis in submerged terrestrial wetland plants

    OpenAIRE

    Colmer, Timothy D.; Winkel, Anders; PEDERSEN, OLE

    2011-01-01

    Background and aims Wetland plants inhabit flood-prone areas and therefore can experience episodes of complete submergence. Submergence impedes exchange of O2 and CO2 between leaves and the environment, and light availability is also reduced. The present review examines limitations to underwater net photosynthesis (P N) by terrestrial (i.e. usually emergent) wetland plants, as compared with submerged aquatic plants, with focus on leaf traits for enhanced CO2 acquisition. Scope Floodwaters are...

  19. Photosynthesis and respiration of some marine benthic algae from Spitsbergen

    OpenAIRE

    Latala, Adam

    1990-01-01

    Light-photosynthesis curves for 9 species of benthic algae from the Hornsund fiord were determined. As a result of adaptation to the conditions in the Arctic, benthic algae from Spitsbergen have a low requirement of light. Saturation and compensation points are low and within a range typical for shadow-tolerant plants.The values for gas exchange rates indicate that Arctic algae have lower photosynthctic capacity than temperate species.

  20. Mimicking the antenna-electron transfer properties of photosynthesis

    OpenAIRE

    Sykora, Milan; Maxwell, Kimberly A.; DeSimone, Joseph M.; Meyer, Thomas J.

    2000-01-01

    A molecular assembly based on derivatized polystyrene is described, which mimics both the light-harvesting and energy-conversion steps of photosynthesis. The system is unique in that the two key parts of a photosynthetic system are incorporated in a functional assembly constructed from polypyridine complexes of RuII. This system is truly artificial, as none of the components used in construction of the assembly are present in a natural photosynthetic system. Quanti...

  1. Anthocyanin-dependent anoxygenic photosynthesis in coloured flower petals?

    OpenAIRE

    Vladimir Lysenko; Tatyana Varduny

    2013-01-01

    Chlorophylless flower petals are known to be composed of non-photosynthetic tissues. Here, we show that the light energy storage that can be photoacoustically measured in flower petals of Petunia hybrida is approximately 10-12%. We found that the supposed chlorophylless photosynthesis is an anoxygenic, anthocyanin-dependent process occurring in blue flower petals (ADAPFP), accompanied by non-respiratory light-dependent oxygen uptake and a 1.5-fold photoinduced increase in ATP levels. Using a ...

  2. Efficient energy transport in photosynthesis: roles of coherence and entanglement

    OpenAIRE

    Patel, Apoorva D

    2011-01-01

    Recently it has been discovered---contrary to expectations of physicists as well as biologists---that the energy transport during photosynthesis, from the chlorophyll pigment that captures the photon to the reaction centre where glucose is synthesised from carbon dioxide and water, is highly coherent even at ambient temperature and in the cellular environment. This process and the key molecular ingredients that it depends on are described. By looking at the process from the computer science v...

  3. Photosynthesis at the forefront of a sustainable life

    OpenAIRE

    Janssen, Paul J. D.; Lambreva, Maya D.; Plumeré, Nicolas; Bartolucci, Cecilia; Antonacci, Amina; Buonasera, Katia; Frese, Raoul N.; Scognamiglio, Viviana; Rea, Giuseppina

    2014-01-01

    The development of a sustainable bio-based economy has drawn much attention in recent years, and research to find smart solutions to the many inherent challenges has intensified. In nature, perhaps the best example of an authentic sustainable system is oxygenic photosynthesis. The biochemistry of this intricate process is empowered by solar radiation influx and performed by hierarchically organized complexes composed by photoreceptors, inorganic catalysts, and enzymes which define specific ni...

  4. Evolution of the extended LHC protein superfamily in photosynthesis

    OpenAIRE

    Engelken, Johannes

    2010-01-01

    In photosynthesis, sunlight interacts with colorful photosynthetic pigments like the chlorophylls, carotenoids and phycobilines. The first two of these pigments can be bound by members of the extended light-harvesting complex (LHC) protein superfamily and are organised in order to take on functions in the collection of or in the defense against sunlight. The extended LHC superfamily comprises several protein families, like the LHCs, the photosystem II subunit S (PSBS), the red algal lineage c...

  5. The Path of Carbon in Photosynthesis XV. Ribulose and Sedoheptulose

    Science.gov (United States)

    Benson, A. A.; Bassham, J. A.; Calvin, M.; Hall, A. G.; Hirsch, H.; Kawaguchi, S.; Lynch, V.; Tolbert, N. E.

    1952-01-01

    The intermediates of carbon dioxide reduction by plants include phosphorylated derivatives of hydroxy acids and sugars. Their identification became possible when the use of labeled carbon dioxide permitted discrimination between the earliest products and the many other components of photosynthetic tissues. A number of compounds were identified by virtue of the chemical and physical properties of the radioactive compounds in tracer amounts and by direct comparison of these properties with those of suspected known metabolic intermediates. It became apparent that several labeled compounds found in short exposures to radioactive carbon dioxide were not substances previously identified as metabolic intermediates. Two phosphate esters in particular were observed in the products of the first few seconds of steady-state photosynthesis by all the photosynthetic microorganisms and higher plants examined in this laboratory. These esters have been isolated by paper chromatography in tracer quantities and enzymatically hydrolyzed to give two sugars, ribulose and sedoheptulose. This paper contains a description of the chemical identification of these sugars and some observations and suggestions regarding the function of their esters. The general importance of these compounds in photosynthesis was summarized before their identification. The products of photosynthesis with C{sup 14}O{sub 2} by each plant included phosphate esters of the same two then unknown compounds in addition to those of the expected glucose, fructose, dihydroxyacetone and glyceric acid. As the time of steady-state photosynthesis in C{sup 14}O{sub 2} decreased, the fractions of total fixed radiocarbon in the esters of the two unidentified compounds increased.

  6. Seasonality of temperate forest photosynthesis and daytime respiration.

    Science.gov (United States)

    Wehr, R; Munger, J W; McManus, J B; Nelson, D D; Zahniser, M S; Davidson, E A; Wofsy, S C; Saleska, S R

    2016-06-30

    Terrestrial ecosystems currently offset one-quarter of anthropogenic carbon dioxide (CO2) emissions because of a slight imbalance between global terrestrial photosynthesis and respiration. Understanding what controls these two biological fluxes is therefore crucial to predicting climate change. Yet there is no way of directly measuring the photosynthesis or daytime respiration of a whole ecosystem of interacting organisms; instead, these fluxes are generally inferred from measurements of net ecosystem-atmosphere CO2 exchange (NEE), in a way that is based on assumed ecosystem-scale responses to the environment. The consequent view of temperate deciduous forests (an important CO2 sink) is that, first, ecosystem respiration is greater during the day than at night; and second, ecosystem photosynthetic light-use efficiency peaks after leaf expansion in spring and then declines, presumably because of leaf ageing or water stress. This view has underlain the development of terrestrial biosphere models used in climate prediction and of remote sensing indices of global biosphere productivity. Here, we use new isotopic instrumentation to determine ecosystem photosynthesis and daytime respiration in a temperate deciduous forest over a three-year period. We find that ecosystem respiration is lower during the day than at night-the first robust evidence of the inhibition of leaf respiration by light at the ecosystem scale. Because they do not capture this effect, standard approaches overestimate ecosystem photosynthesis and daytime respiration in the first half of the growing season at our site, and inaccurately portray ecosystem photosynthetic light-use efficiency. These findings revise our understanding of forest-atmosphere carbon exchange, and provide a basis for investigating how leaf-level physiological dynamics manifest at the canopy scale in other ecosystems. PMID:27357794

  7. Seasonality of temperate forest photosynthesis and daytime respiration

    Science.gov (United States)

    Wehr, R.; Munger, J. W.; McManus, J. B.; Nelson, D. D.; Zahniser, M. S.; Davidson, E. A.; Wofsy, S. C.; Saleska, S. R.

    2016-06-01

    Terrestrial ecosystems currently offset one-quarter of anthropogenic carbon dioxide (CO2) emissions because of a slight imbalance between global terrestrial photosynthesis and respiration. Understanding what controls these two biological fluxes is therefore crucial to predicting climate change. Yet there is no way of directly measuring the photosynthesis or daytime respiration of a whole ecosystem of interacting organisms; instead, these fluxes are generally inferred from measurements of net ecosystem–atmosphere CO2 exchange (NEE), in a way that is based on assumed ecosystem-scale responses to the environment. The consequent view of temperate deciduous forests (an important CO2 sink) is that, first, ecosystem respiration is greater during the day than at night; and second, ecosystem photosynthetic light-use efficiency peaks after leaf expansion in spring and then declines, presumably because of leaf ageing or water stress. This view has underlain the development of terrestrial biosphere models used in climate prediction and of remote sensing indices of global biosphere productivity. Here, we use new isotopic instrumentation to determine ecosystem photosynthesis and daytime respiration in a temperate deciduous forest over a three-year period. We find that ecosystem respiration is lower during the day than at night—the first robust evidence of the inhibition of leaf respiration by light at the ecosystem scale. Because they do not capture this effect, standard approaches overestimate ecosystem photosynthesis and daytime respiration in the first half of the growing season at our site, and inaccurately portray ecosystem photosynthetic light-use efficiency. These findings revise our understanding of forest–atmosphere carbon exchange, and provide a basis for investigating how leaf-level physiological dynamics manifest at the canopy scale in other ecosystems.

  8. Understanding of photosynthesis among pupils of technical secondary schools

    OpenAIRE

    Pavić, Petra

    2014-01-01

    The goal of our research was to examine the knowledge on photosynthesis of the students of the Secondary Technical schools, and their attitude towards it, and whether they have misconceptions about it. The research was conducted on a sample of 466 students in Vegova Secondary Technical and Grammar School of Electrical Engineering and Computer Science in Ljubljana in the first, second and third year of electrical engineering and computer science programme. The test contained 27 closed-ended qu...

  9. Regressive Evolution of Photosynthesis in the Roseobacter Clade

    Czech Academy of Sciences Publication Activity Database

    Koblížek, Michal; Zeng, Yonghui; Horák, A.; Oborník, Miroslav

    2013-01-01

    Roč. 66, č. 2013 (2013), s. 385-405. ISSN 0065-2296 R&D Projects: GA ČR GAP501/10/0221; GA ČR GBP501/12/G055; GA MŠk ED2.1.00/03.0110 Institutional support: RVO:61388971 Keywords : roseobacter clade * photosynthesis * marine microbial communities Subject RIV: EE - Microbiology, Virology Impact factor: 1.740, year: 2013

  10. Photosynthesis of ground vegetation in boreal Scots pine forests

    OpenAIRE

    Kulmala, Liisa

    2011-01-01

    Research on carbon uptake in boreal forests has mainly focused on mature trees, even though ground vegetation species are effective assimilators and can substantially contribute to the CO2 uptake of forests. Here, I examine the photosynthesis of the most common species of ground vegetation in a series of differently aged Scots pine stands, and at two clear-cut sites with substantial differences in fertility. In general, the biomass of evergreen species was highest at poor sites and below cano...

  11. Human Photosynthesis and Central Nervous System´s Diseases

    Directory of Open Access Journals (Sweden)

    Arturo Solis HERRERA

    2012-09-01

    Full Text Available Photosynthesis in plants is considered the most important chemical reaction in the world because is the first step in the food chain. The first clues of the process were detected by Lavoisier and others during the XVIII century, but the exact nature of the chemical reactions involved remain poorly understood. Moreover, dissociation of the water molecule constitutes the very first reaction of photosynthesis in plants, and was unsuspected, even unthinkable in human beings, until we found it in human retina in 1990s. The discovery of the amazing capacity of our body to makes the dissociation of the water molecule, breaks the paradigm: Plants and human beings have the same very first reaction as the origin of life. The impact in the field of molecular biology is huge; therefore the role of the water and glucose must be redefined, glucose is just a source of biomass, instead water is the real source of energy of the eukaryotic cell, and neuron cell is not an exception. The main source of energy of the CNS is the CSF and therefore the ventricles and subarachnoid space. Blood vessels are merely source of biomass. By the analogy with the process in plants, our discovery was named human photosynthesis. Human being begin to lose the capacity to split the water molecule at 26 years old, ca. 10 % each decade, and after fifties goes into free fall. Our research along these 23 years thought us that medical modulation of human photosynthesis has extraordinary therapeutic results in CNS´s diseases.

  12. PHOTOSYNTHESIS AT THE FOREFRONT OF A SUSTAINABLE LIFE

    OpenAIRE

    GiuseppinaRea; PaulJ.D.Janssen; NicolasPlumeré; RaoulN.Frese

    2014-01-01

    The development of a sustainable bio-based economy has drawn much attention in recent years, and research to find smart solutions to the many inherent challenges has intensified. In nature, perhaps the best example of an authentic sustainable system is oxygenic photosynthesis. The biochemistry of this intricate process is empowered by solar radiation influx and performed by hierarchically organized complexes composed by photoreceptors, inorganic catalysts, and enzymes which define specific ni...

  13. Radiation balance, transpiration and photosynthesis of an isolated tree

    International Nuclear Information System (INIS)

    The radiation balance of an isolated walnut tree was measured using an experimental Whirligig device. The total amount of all-wave radiation absorbed by the tree canopy was used to estimate transpiration rates using a Penman-Monteith model. The results compared favourably with tree water use, measured by the heat-pulse technique. The total amount of photosynthetically active radiation (PAR) absorbed by the tree canopy was combined with a photosynthetic light response curve to estimate net photosynthesis rates. The results compare favourably with published data from other tree canopies. Daily energy balance calculations showed that on average, about two-thirds of the total radiant energy absorbed by the tree canopy was dissipated as latent heat in the form of transpiration. The dominant environmental variable influencing transpiration was the vapour pressure deficit of the air. Almost two-thirds of the net latent heat flux was attributable to the vapour pressure deficit component, with the remainder owing to the radiation component. Daily transpiration-assimilation ratios varied from day to day in response to changing environmental conditions, but generally decreased with increasing net photosynthesis and with increasing transpiration. This appears to be the first time that such a direct measurement of the energy balance and photosynthesis of a single tree has been made. (author)

  14. On the variation of alkalinity during phytoplankton photosynthesis

    Directory of Open Access Journals (Sweden)

    2005-01-01

    Full Text Available The alkalinity of the organic constituents of marine phytoplankton and their participation in the total alkalinity (TA change of seawater during photosynthesis are carefully assessed. Quantification of the contribution of phytoplankton chlorophyll, proteins and phosphorus compounds to the hydrogen ion balance of seawater in terms of total inorganic nitrogen (∆[NT] = ∆[NH4 +] + ∆[N2] + ∆[NO2 –] + ∆[NO3 –] and total inorganic phosphorus (∆[PT] changes during photosynthesis yielded that the organic components of marine phytoplankton are alkaline by –0.06 × ∆[NT] – 0.49 × ∆[PT], and that the potential total alkalinity (TAP during photosynthesis is TAP = TA – [NH4 –] + 0.93 × [NO2 –] + [NO3 –] + 0.08 × [NT] + 0.23 × [PT] for unfiltered seawater samples and TAP = TA – [NH4 –] + 0.93 × [NO2 –] + [NO3 –] + 0.02 × [NT] + 0.26 × [PT] for filtered seawater samples. These equations correct the traditionally used expression TAP = TA + [NO3 –]. The TAP anomalies are produced, in order of increasing importance, by N2 fixation, DMSP production and CaCO3 fixation.

  15. PHOTOSYNTHESIS AT THE FOREFRONT OF A SUSTAINABLE LIFE

    Directory of Open Access Journals (Sweden)

    Paul J.D. Janssen

    2014-06-01

    Full Text Available The development of a sustainable bio-based economy has drawn much attention in recent years, and research to find smart solutions to the many inherent challenges has intensified. In nature, perhaps the best example of an authentic sustainable system is oxygenic photosynthesis. The biochemistry of this intricate process is empowered by solar radiation influx and performed by hierarchically organized complexes composed by photoreceptors, inorganic catalysts, and enzymes which define specific niches for optimizing light-to-energy conversion. The success of this process relies on its capability to exploit the almost inexhaustible reservoirs of sunlight, water, and carbon dioxide to transform photonic energy into chemical energy such as stored in adenosine triphosphate. Oxygenic photosynthesis is responsible for most of the oxygen, fossil fuels, and biomass on our planet. So, even after a few billion years of evolution, this process unceasingly supports life on earth, and probably soon also in outer-space, and inspires the development of enabling technologies for a sustainable global economy and ecosystem. The following review covers some of the major milestones reached in photosynthesis research, each reflecting lasting routes of innovation in agriculture, environmental protection, and clean energy production.

  16. The social acceptance of artificial photosynthesis: towards a conceptual framework.

    Science.gov (United States)

    Sovacool, Benjamin K; Gross, Allan

    2015-06-01

    Advancements in artificial photosynthesis have the potential to radically transform how societies convert and use energy. Their successful development, however, hinges not only on technical breakthroughs, but also acceptance and adoption by energy users. This article introduces a conceptual framework enabling analysts, planners and even investors to determine environments where artificial photosynthesis may thrive, and those where it may struggle. Drawn from work looking at the barriers and acceptance of solar photovoltaic and wind energy systems, the article proposes that social acceptance has multiple dimensions-socio-political, community and market-that must be met holistically in order for investors and users to embrace new technologies. The article argues that any future market acceptance for artificial photosynthesis will depend upon the prevalence of nine factors, which create conducive environments; the lack of the conditions engenders environments where they will likely be rejected. The conditions are (i) strong institutional capacity; (ii) political commitment; (iii) favourable legal and regulatory frameworks; (iv) competitive installation and/or production costs; (v) mechanisms for information and feedback; (vi) access to financing; (vii) prolific community and/or individual ownership and use; (viii) participatory project siting; and (ix) recognition of externalities or positive public image. PMID:26052424

  17. On oxygenic photosynthesis in planets of Red Dwarfs

    Science.gov (United States)

    Wandel, Amri; Gale, Joseph

    2015-08-01

    The results of the Kepler mission indicate that Earthlike planets are common not only around solar-type stars but also among planets orbiting Red Dwarf (RD) stars, the most numerous stellar type in the Milky Way galaxy. Early considerations indicated that conditions on RD planets would be inimical to life, as their Habitable Zones would be so close as to make planets tidally locked to their star. This was thought to cause an erratic climate and expose life forms to flares of ionizing electro-magnetic radiation and charged particles. It has also been argued that the lesser photon energy of the radiation of the relatively cool RDs would not suffice for oxygenic photosynthesis. However, recent calculations show that these negative factors are less severe than originally estimated, hence conditions for photosynthesis could exist on RD planets. Furthermore, the huge number and the long Main-Sequence lifetime of RDs could make photosynthesis and biotic life on RD planets statistically even more abundant than on planets of solar type stars.

  18. NDH-1 and NDH-2 Plastoquinone Reductases in Oxygenic Photosynthesis.

    Science.gov (United States)

    Peltier, Gilles; Aro, Eva-Mari; Shikanai, Toshiharu

    2016-04-29

    Oxygenic photosynthesis converts solar energy into chemical energy in the chloroplasts of plants and microalgae as well as in prokaryotic cyanobacteria using a complex machinery composed of two photosystems and both membrane-bound and soluble electron carriers. In addition to the major photosynthetic complexes photosystem II (PSII), cytochrome b6f, and photosystem I (PSI), chloroplasts also contain minor components, including a well-conserved type I NADH dehydrogenase (NDH-1) complex that functions in close relationship with photosynthesis and likewise originated from the endosymbiotic cyanobacterial ancestor. Some plants and many microalgal species have lost plastidial ndh genes and a functional NDH-1 complex during evolution, and studies have suggested that a plastidial type II NADH dehydrogenase (NDH-2) complex substitutes for the electron transport activity of NDH-1. However, although NDH-1 was initially thought to use NAD(P)H as an electron donor, recent research has demonstrated that both chloroplast and cyanobacterial NDH-1s oxidize reduced ferredoxin. We discuss more recent findings related to the biochemical composition and activity of NDH-1 and NDH-2 in relation to the physiology and regulation of photosynthesis, particularly focusing on their roles in cyclic electron flow around PSI, chlororespiration, and acclimation to changing environments. PMID:26735062

  19. The Path of Carbon in Photosynthesis. XX. The Steady State

    Energy Technology Data Exchange (ETDEWEB)

    Calvin, M.; Massini, Peter

    1952-09-01

    The separation of the phenomenon of photosynthesis in green plants into a photochemical reaction and into the light-dependent reduction of carbon dioxide is discussed, The reduction of carbon dioxide and the fate of the assimilated carbon were investigated with the help of the tracer technique (exposure of the planks to the radioactive C{sup 14}O{sub 2}) and of paper chromatography. A reaction cycle is proposed in which phosphoglyceric acid is the first isolable assimilations product. Analyses of the algal extracts which had assimilated radioactive carbon dioxide in a stationary condition ('steady-state' photosynthesis) for a long time provided further information concerning the proposed cycle and permitted the approximate estimation, for a number of compounds of what fraction of each compound was taking part in the cycle. The earlier supposition that light influences the respiration cycle was confirmed. The possibility of the assistance of {alpha}-lipoic acid, or of a related substance, in this influence and in the photosynthesis cycle, is discussed.

  20. C4 photosynthesis evolution: the conditional Mt. Fuji.

    Science.gov (United States)

    Heckmann, David

    2016-06-01

    C4 photosynthesis implements a biochemical carbon pump to suppress photorespiration. While this mechanism allows for increased photosynthetic efficiency, it requires the ancestral C3 state to be modified in terms of leaf anatomy, expression of metabolic genes, and enzyme kinetics. Despite the complexity of the C4 syndrome, it evolved in more than 60 independent lineages. Because the phylogenetic distribution of these origins appears to be non-random, enabling factors that are initially unrelated to C4 photosynthesis are assumed to be acting in certain C3 lineages. In recent years, substantial progress has been made on firstly, the nature of enabling events and finally, quantitative models of C4 evolution that are based on C3-C4 intermediate species. I discuss the synthesis of these approaches as a consensus trajectory towards C4 photosynthesis and hypothesize on the effect of enabling factors on the fitness landscape of C4 evolution. A complete understanding of these mechanisms will require both further experimental studies and improved quantitative models of leaf physiology. PMID:27153468

  1. Ecosystem respiration depends strongly on photosynthesis in a temperate heath

    DEFF Research Database (Denmark)

    Larsen, Klaus Steenberg; Ibrom, A.; Beier, C.;

    2007-01-01

    We measured net ecosystem CO2 flux (F-n) and ecosystem respiration (R-E), and estimated gross ecosystem photosynthesis (P-g) by difference, for two years in a temperate heath ecosystem using a chamber method. The exchange rates of carbon were high and of similar magnitude as for productive forest...... ecosystems with a net ecosystem carbon gain during the second year of 293 +/- 11 g C m(-2) year(-1) showing that the carbon sink strength of heather-dominated ecosystems may be considerable when C. vulgaris is in the building phase of its life cycle. The estimated gross ecosystem photosynthesis and ecosystem.......65) was improved when the P-g rate was incorporated into the model (second year; R-2 = 0.79), suggesting that daytime R-E increased with increasing photosynthesis. Furthermore, the temperature sensitivity of R-E decreased from apparent Q(10) values of 3.3 to 3.9 by the classic equation to a more realistic...

  2. Photosynthesis at the forefront of a sustainable life.

    Science.gov (United States)

    Janssen, Paul J D; Lambreva, Maya D; Plumeré, Nicolas; Bartolucci, Cecilia; Antonacci, Amina; Buonasera, Katia; Frese, Raoul N; Scognamiglio, Viviana; Rea, Giuseppina

    2014-01-01

    The development of a sustainable bio-based economy has drawn much attention in recent years, and research to find smart solutions to the many inherent challenges has intensified. In nature, perhaps the best example of an authentic sustainable system is oxygenic photosynthesis. The biochemistry of this intricate process is empowered by solar radiation influx and performed by hierarchically organized complexes composed by photoreceptors, inorganic catalysts, and enzymes which define specific niches for optimizing light-to-energy conversion. The success of this process relies on its capability to exploit the almost inexhaustible reservoirs of sunlight, water, and carbon dioxide to transform photonic energy into chemical energy such as stored in adenosine triphosphate. Oxygenic photosynthesis is responsible for most of the oxygen, fossil fuels, and biomass on our planet. So, even after a few billion years of evolution, this process unceasingly supports life on earth, and probably soon also in outer-space, and inspires the development of enabling technologies for a sustainable global economy and ecosystem. The following review covers some of the major milestones reached in photosynthesis research, each reflecting lasting routes of innovation in agriculture, environmental protection, and clean energy production. PMID:24971306

  3. A Space Cam Mechanism for Power Transmission of an Opposite-cylinder Piston Engine

    Directory of Open Access Journals (Sweden)

    Zhang Haoyue

    2015-01-01

    Full Text Available For the purpose of improving the engine’s power density, we put forward a new type of power transmission mechanism which is used for opposed-cylinder engine. The gas pressure acts on the cam through the piston and push rod, and the spindle rotation of external is driven by the cam. The design of spatial cam work surface is completed by using the enveloping theory of a family of space curves, the force between roller and cam is analyzed using dynamic analysis software. Under the condition of equal number, size and stroke of piston, the new one with larger power density is more compact in structure than the traditional power transmission mechanism, and the reaction force on either side of the main shaft and the acting force between pistons and cylinders are smaller than those in traditional one, which prolongs the service life of the pistons.

  4. CAD/CAM/CAI Application for High-Precision Machining of Internal Combustion Engine Pistons

    Directory of Open Access Journals (Sweden)

    V. V. Postnov

    2014-07-01

    Full Text Available CAD/CAM/CAI application solutions for internal combustion engine pistons machining was analyzed. Low-volume technology of internal combustion engine pistons production was proposed. Fixture for CNC turning center was designed.

  5. Development of CAD/CAM System for Cross Section’s Changing Hole Electrical Discharge Machining

    Science.gov (United States)

    Ishida, Tohru; Ishiguro, Eiki; Kita, Masahiko; Nakamoto, Keiichi; Takeuchi, Yoshimi

    This study deals with the development of a new CAD/CAM system for fabricating holes whose cross sections change variously. The cross sections of machined holes are generally constant. The limitations in the shapes of holes that can be machined make obstacles in the design stage of industrial products. A new device that utilizes electrical discharge machining has been developed that can create holes with various cross sections to solve this problem. However, it has been impossible to put the device into practical use since there has been no software that has enabled the designed shapes to be easily machined. Therefore, we aimed at developing a new CAD/CAM system for machining the beforehand designed holes with changing cross sections by using the device. As the first step in developing the CAD/CAM system, the post processor in the CAM system is formulated in this paper.

  6. Study on glass infiltrated alumina(GIA) ceramic for CAD/CAM

    Institute of Scientific and Technical Information of China (English)

    LI Mingzhe; LI Hong; WANG Wei; Zhao Yunfeng

    2001-01-01

    @@ With the rapid development of computer technique , Computer aided design(CAD) and computer aided manufacturing(CAM) or computer integrated manufacturing(CIM) has became an alternative to the conventional technique for producingdental restorations.

  7. Mathematical Modeling of the Numerical Control Cam Grinder Wheel Center Displacement and Its Application

    Institute of Scientific and Technical Information of China (English)

    WANG Xiaojun; LIU Zhaohui

    2006-01-01

    Considering grinding a cam with numerical control (NC) cam grinder, a mathematical model should be established with the unified parameter based on the original cam-lobe lift data to describe the movement of wheel and establish the relation between the wheel center coordinate, the measuring angle and workpiece's spindle rotation angle. By analyzing, the grinding wheel can be regarded as different followers. To the planar and roller followers, different mathematical models are established, but they can be unified in Eqs.(17) of this paper with the different value of the roller radius r1. And also the model is suit for the edged follower when assuming the roller radius r1=0. Experimental verification was done with TKM120 CNC/CBN grinder with NC sets' interpolation according to the model, which shows that high precision parts can be manufactured and this mathematical model can be practically applied for NC cam grinder.

  8. ROLLING CONDITION FOR ROLLERS ALONG CAMS IN COLD DOUBLE-SET MULTI-ROLLER TUBE ROLLING

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    The necessary condition of pure rolling for the rollers moving along its individual cams are obtained by the analysis of the loading status of the rollers and it provides a theoretical basis for adjustment of rolling stand.

  9. Cam Femoroacetabular Impingement as a Possible Explanation of Recalcitrant Anterior Knee Pain

    Directory of Open Access Journals (Sweden)

    Vicente Sanchis-Alfonso

    2016-01-01

    Full Text Available We present a case of a patient with chronic anterior knee pain (AKP recalcitrant to conservative treatment who returned to our office for severe hip pain secondary to Cam femoroacetabular impingement (Cam FAI at 10 months after the onset of knee pain. This case highlights the fact that the main problem is not in the patella but in the hip in some patients with AKP. We hypothesize that there is an external femoral rotation in order to avoid the impingement and therefore the hip pain in patients with Cam FAI. This functional femoral rotation could provoke a patellofemoral imbalance that may be, in theory, responsible for patellofemoral pain in this particular patient. In our case, Cam FAI resolution was related to the resolution of AKP.

  10. A Unique Opportunity for an Intercultural Discussion on CAM and Liver Disease

    Directory of Open Access Journals (Sweden)

    Francesco Marotta

    2005-01-01

    Full Text Available The meeting of the APASL, Asian Pacific Association for the Study of the Liver, was held in December 2004, in New Delhi, India. The meeting was held under the patronage of the APASL Committee and Board of Presidents of the National Liver Association and in conjunction with the annual conference of the Indian Association for the Study of Liver (INASL. The congress was designed to have a core meeting with three parallel sessions running throughout, dedicated research workshops and intensive breakfast sessions. This report concentrates on the two sessions devoted to complementary and alternative medicine (CAM and shows the latest research in CAM for liver disease and the concerns of doctors about integrating CAM with more traditional treatments. With researchers and practitioners gathering from all over the world, it was a unique opportunity for an intercultural discussion on CAM and liver disease.

  11. Commissioning and First Observations with Wide FastCam at the Telescopio Carlos S\\'anchez

    CERN Document Server

    Velasco, Sergio; Oscoz, Alejandro; López, Roberto L; Puga, Marta; Murga, Gaizka; Pérez-Garrido, Antonio; Pallé, Enric; Ricci, Davide; Ayuso, Ismael; Hernández-Sánchez, Mónica; Truant, Nicola

    2016-01-01

    The FastCam instrument platform, jointly developed by the IAC and the UPCT, allows, in real-time, acquisition, selection and storage of images with a resolution that reaches the diffraction limit of medium-sized telescopes. FastCam incorporates a specially designed software package to analyse series of tens of thousands of images in parallel with the data acquisition at the telescope. Wide FastCam is a new instrument that, using the same software for data acquisition, does not look for lucky imaging but fast observations in a much larger field of view. Here we describe the commissioning process and first observations with Wide FastCam at the Telescopio Carlos S\\'anchez (TCS) in the Observatorio del Teide.

  12. Spectral Signatures of Photosynthesis. I. Review of Earth Organisms

    Science.gov (United States)

    Kiang, Nancy Y.; Siefert, Janet; Govindjee; Blankenship, Robert E.

    2007-02-01

    Why do plants reflect in the green and have a ``red edge '' in the red, and should extrasolar photosynthesis be the same? We provide (1) a brief review of how photosynthesis works, (2) an overview of the diversity of photosynthetic organisms, their light harvesting systems, and environmental ranges, (3) a synthesis of photosynthetic surface spectral signatures, and (4) evolutionary rationales for photosynthetic surface reflectance spectra with regard to utilization of photon energy and the planetary light environment. We found the `` near-infrared (NIR) end '' of the red edge to trend from blue-shifted to reddest for (in order) snow algae, temperate algae, lichens, mosses, aquatic plants, and finally terrestrial vascular plants. The red edge is weak or sloping in lichens. Purple bacteria exhibit possibly a sloping edge in the NIR. More studies are needed on pigment-protein complexes, membrane composition, and measurements of bacteria before firm conclusions can be drawn about the role of the NIR reflectance. Pigment absorbance features are strongly correlated with features of atmospheric spectral transmittance: P680 in Photosystem II with the peak surface incident photon flux density at ~685 nm, just before an oxygen band at 687.5 nm; the NIR end of the red edge with water absorbance bands and the oxygen A-band at 761 nm; and bacteriochlorophyll reaction center wavelengths with local maxima in atmospheric and water transmittance spectra. Given the surface incident photon flux density spectrum and resonance transfer in light harvesting, we propose some rules with regard to where photosynthetic pigments will peak in absorbance: (1) the wavelength of peak incident photon flux; (2) the longest available wavelength for core antenna or reaction center pigments; and (3) the shortest wavelengths within an atmospheric window for accessory pigments. That plants absorb less green light may not be an inefficient legacy of evolutionary history, but may actually satisfy the

  13. Nonlinear System Modeling, Optimal Cam Design, and Advanced System Control for an Electromechanical Engine Valve Drive

    OpenAIRE

    Qiu, Yihui; Perreault, David J.; Keim, Thomas A.; Kassakian, John G.

    2011-01-01

    A cam-based shear force-actuated electromechanical valve drive system offering variable valve timing in internal combustion engines was previously proposed and demonstrated. To transform this concept into a competitive commercial product, several major challenges need to addressed, including the reduction of power consumption, transition time, and size. As shown in this paper, by using nonlinear system modeling, optimizing cam design, and exploring different control strategies, the power cons...

  14. Accuracy and safety of second-generation PillCam COLON capsule for colorectal polyp detection

    OpenAIRE

    Spada, Cristiano; De Vincentis, Fabio; Cesaro, Paola; Hassan, Cesare; Riccioni, Maria Elena; Minelli Grazioli, Leonardo; Bolivar, Santiago; Zurita, Andrade; Costamagna, Guido

    2012-01-01

    PillCam COLON capsule endoscopy (CCE) (Given Imaging Ltd, Yoqneam, Israel) is one of the most recent diagnostic, endoscopic technologies designed to explore the colon. CCE is a noninvasive, patient-friendly technique that is able to explore the colon without requiring sedation and air insufflation. The first generation of CCE was released onto the market in 2006 and although it generated great enthusiasm, it showed suboptimal accuracy. Recently, a second-generation system (PillCam COLON 2) (C...

  15. CAM, free speech, and the British legal system: overstepping the mark?

    Science.gov (United States)

    Milgrom, Lionel R

    2009-10-01

    The British Chiropractic Association recently won a libel case against the science writer and CAM 'skeptic' Dr Simon Singh for publishing an article in a British newspaper in which he accused them of promoting 'bogus' treatments. This has ignited a campaign in the UK to 'keep the libel laws out of science'. In this article, the tension between media freedom of expression and defamation law is examined, and possible ramifications for CAM in the UK explored. PMID:19848549

  16. Why do Norwegian nurses leave the public health service to practice CAM?

    OpenAIRE

    Johannessen, Berit

    2009-01-01

    This paper explores a number of issues associated with the recent increase in nurses choosing to leave the Norwegian health care system in order to become independent practitioners of complementary and alternative medicine (CAM). The paper suggests that in Norway, nurses perceive medical hegemony continues to persist. Nurses perceive restrictions in their ability to develop their professional roles and status. CAM would appear to offer many nurses, the opportunity to develop their clinica...

  17. CAM within a field force of countervailing powers: The case of Portugal.

    Science.gov (United States)

    Almeida, Joana; Gabe, Jonathan

    2016-04-01

    This paper examines the extent to which the position of the medical profession and the state towards complementary and alternative medicine (CAM) practitioners has changed since the late 1990s, taking Portugal as a case study. Using Light's concept of countervailing powers, we consider the alliances, interests, rhetoric and degrees of control between these three actors over time, focussing particularly on the extent to which CAM practitioners have acted as a countervailing force in their relationship with the medical profession and the state. It also brings to the fore the position of supra-state agencies concerning CAM regulation. A critical discourse analysis was conducted on data derived from a systematic search of information dating from the late 1990s up to 2015. Our analysis suggests that CAM has emerged as an active player and a countervailing power in that it has had significant influence on the process of state policy-making. The medical profession, in turn, has moved from rejecting to 'incorporating' CAM, while the state has acted as a 'broker', trying to accommodate the demands and preferences of both actors while simultaneously demonstrating its power and autonomy in shaping health policy. In sum, the history of countermoves of CAM, the medical profession and the state in recasting power relations regarding CAM regulation in Portugal has highlighted the explanatory value of Light's countervailing power theory and the need to move away from a professional dominance and corporatist approach, in which CAM has simply been seen as subjugated to the power of the medical profession and the state. PMID:26990177

  18. Effects of Different Calcium Reagents on Photosynthesis Characteristics of Catharanthus roseus%不同钙效应剂对长春花光合特性的影响

    Institute of Scientific and Technical Information of China (English)

    孙金春; 张扬欢; 温泉; 张楠; 唐娟; 吴能表

    2011-01-01

    The effects of LaCl3 (a plasmalemma calcium channel blocker), herpain (an intracellular IP3 channel blocker) and trifluoperazine (an intracellular CaM activity inhibitor) on the photosynthesis of Ca-tharanthus roseus were researched. All the calcium channel blockers studied decreased Pn (net photosynthesis rate), maximal PSII quantum (Fv/Fm), PSII quantum yield (Yield), relative electron transport rate (ETR) and photochemical quenching (qP) of C. Roseus and increased its non-photochemical quenching (qN), chlorophyll a concentration, chlorophyll b concentration and chlorophyll a+b. It is, therefore, concluded that the calcium channel greatly influenced the photosynthesis of C. Roseus by a special way other than promoting the degradation of photosynthetic pigments or the inhibition of their synthesis to inhibit the photosynthesis of C. Roseus. Herpain affected photosynthesis of C. Roseus most significantly, which means the calcium released by intracellular calcium pool through the IP3 channel plays an important role in the photosynthesis of C. Roseus.%研究了细胞质膜钙通道阻断剂氯化镧(LaCl3)、胞内IP3通道阻断剂肝素(Heparin)、胞内CaM活性抑制剂三氟啦嗪(TFP)对长春花光合作用的影响,结果发现:Ca2+通道阻断剂处理后长春花叶片净光合速率(Pn)、PSII最大量子产量(Fv/Fm)、PSⅡ实际量子产量(Yield)、电子传递速率(ETR)、光化学淬灭系数(qP)均下降,非光化学淬灭系数(qN)及Chla、Chlb、Chla+Chlb含量上升,表明Ca2+通道阻断剂对长春花的光合作用有较大影响,且不是通过加速叶片光合色素降解或抑制其合成来实现抑制叶片的光合能力;其中Heparin处理的长春花叶片相关参数变化幅度最大,表明胞内钙库通过IP3通道释放的Ca2+在长春花叶片光合作用过程中发挥了更积极的作用.

  19. Rising CO2 widens the transpiration-photosynthesis optimality space

    Science.gov (United States)

    de Boer, Hugo J.; Eppinga, Maarten B.; Dekker, Stefan C.

    2016-04-01

    Stomatal conductance (gs) and photosynthetic biochemistry, typically expressed by the temperature-adjusted maximum rates of carboxylation (V cmax) and electron transport (Jmax), are key traits in land ecosystem models. Contrary to the many approaches available for simulating gs responses, the biochemical parameters V cmax and Jmax are often treated as static traits in ecosystem models. However, observational evidence indicates that V cmax and Jmax respond to persistent changes in atmospheric CO2. Hence, ecosystem models may be improved by incorporating coordinated responses of photosynthetic biochemistry and gs to atmospheric CO2. Recently, Prentice et al. (2014) proposed an optimality framework (referred to as the Prentice framework from here on) to predict relationships between V cmax and gs based on Fick's law, Rubisco-limited photosynthesis and the carbon costs of transpiration and photosynthesis. Here we show that this framework is, in principle, suited to predict CO2-induced changes in the V cmax ‑gs relationships. The framework predicts an increase in the V cmax:gs-ratio with higher atmospheric CO2, whereby the slope of this relationship is determined by the carbon costs of transpiration and photosynthesis. For our empirical analyses we consider that the carbon cost of transpiration is positively related to the plant's Huber value (sapwood area/leaf area), while the carbon cost of photosynthesis is positively related to the maintenance cost of the photosynthetic proteins. We empirically tested the predicted effect of CO2 on the V cmax:gs-ratio in two genotypes of Solanum dulcamara (bittersweet) that were grown from seeds to maturity under 200, 400 and 800 ppm CO2 in walk-in growth chambers with tight control on light, temperature and humidity. Seeds of the two Solanum genotypes were obtained from two distinct natural populations; one adapted to well-drained sandy soil (the 'dry' genotype) and one adapted to poorly-drained clayey soil (the 'wet' genotype

  20. Rationale for the Use of CAD/CAM Technology in Implant Prosthodontics

    Science.gov (United States)

    Abduo, Jaafar; Lyons, Karl

    2013-01-01

    Despite the predictable longevity of implant prosthesis, there is an ongoing interest to continue to improve implant prosthodontic treatment and outcomes. One of the developments is the application of computer-aided design and computer-aided manufacturing (CAD/CAM) to produce implant abutments and frameworks from metal or ceramic materials. The aim of this narrative review is to critically evaluate the rationale of CAD/CAM utilization for implant prosthodontics. To date, CAD/CAM allows simplified production of precise and durable implant components. The precision of fit has been proven in several laboratory experiments and has been attributed to the design of implants. Milling also facilitates component fabrication from durable and aesthetic materials. With further development, it is expected that the CAD/CAM protocol will be further simplified. Although compelling clinical evidence supporting the superiority of CAD/CAM implant restorations is still lacking, it is envisioned that CAD/CAM may become the main stream for implant component fabrication. PMID:23690778