Search Results - (Author, Cooperation:M. Litvak)
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1Latest Papers from Table of Contents or Articles in PressW. R. Anderegg ; C. Schwalm ; F. Biondi ; J. J. Camarero ; G. Koch ; M. Litvak ; K. Ogle ; J. D. Shaw ; E. Shevliakova ; A. P. Williams ; A. Wolf ; E. Ziaco ; S. Pacala
American Association for the Advancement of Science (AAAS)
Published 2015Staff ViewPublication Date: 2015-08-01Publisher: American Association for the Advancement of Science (AAAS)Print ISSN: 0036-8075Electronic ISSN: 1095-9203Topics: BiologyChemistry and PharmacologyComputer ScienceMedicineNatural Sciences in GeneralPhysicsKeywords: *Carbon Cycle ; *Climate Change ; *Droughts ; Europe ; *Forests ; Models, Theoretical ; Trees/*growth & development ; United StatesPublished by: -
2Latest Papers from Table of Contents or Articles in PressC. R. Webster ; P. R. Mahaffy ; G. J. Flesch ; P. B. Niles ; J. H. Jones ; L. A. Leshin ; S. K. Atreya ; J. C. Stern ; L. E. Christensen ; T. Owen ; H. Franz ; R. O. Pepin ; A. Steele ; C. Achilles ; C. Agard ; J. A. Alves Verdasca ; R. Anderson ; D. Archer ; C. Armiens-Aparicio ; R. Arvidson ; E. Atlaskin ; A. Aubrey ; B. Baker ; M. Baker ; T. Balic-Zunic ; D. Baratoux ; J. Baroukh ; B. Barraclough ; K. Bean ; L. Beegle ; A. Behar ; J. Bell ; S. Bender ; M. Benna ; J. Bentz ; G. Berger ; J. Berger ; D. Berman ; D. Bish ; D. F. Blake ; J. J. Blanco Avalos ; D. Blaney ; J. Blank ; H. Blau ; L. Bleacher ; E. Boehm ; O. Botta ; S. Bottcher ; T. Boucher ; H. Bower ; N. Boyd ; B. Boynton ; E. Breves ; J. Bridges ; N. Bridges ; W. Brinckerhoff ; D. Brinza ; T. Bristow ; C. Brunet ; A. Brunner ; W. Brunner ; A. Buch ; M. Bullock ; S. Burmeister ; M. Cabane ; F. Calef ; J. Cameron ; J. Campbell ; B. Cantor ; M. Caplinger ; J. Caride Rodriguez ; M. Carmosino ; I. Carrasco Blazquez ; A. Charpentier ; S. Chipera ; D. Choi ; B. Clark ; S. Clegg ; T. Cleghorn ; E. Cloutis ; G. Cody ; P. Coll ; P. Conrad ; D. Coscia ; A. Cousin ; D. Cremers ; J. Crisp ; A. Cros ; F. Cucinotta ; C. d'Uston ; S. Davis ; M. Day ; M. de la Torre Juarez ; L. DeFlores ; D. DeLapp ; J. DeMarines ; D. DesMarais ; W. Dietrich ; R. Dingler ; C. Donny ; B. Downs ; D. Drake ; G. Dromart ; A. Dupont ; B. Duston ; J. Dworkin ; M. D. Dyar ; L. Edgar ; K. Edgett ; C. Edwards ; L. Edwards ; B. Ehlmann ; B. Ehresmann ; J. Eigenbrode ; B. Elliott ; H. Elliott ; R. Ewing ; C. Fabre ; A. Fairen ; K. Farley ; J. Farmer ; C. Fassett ; L. Favot ; D. Fay ; F. Fedosov ; J. Feldman ; S. Feldman ; M. Fisk ; M. Fitzgibbon ; M. Floyd ; L. Fluckiger ; O. Forni ; A. Fraeman ; R. Francis ; P. Francois ; C. Freissinet ; K. L. French ; J. Frydenvang ; A. Gaboriaud ; M. Gailhanou ; J. Garvin ; O. Gasnault ; C. Geffroy ; R. Gellert ; M. Genzer ; D. Glavin ; A. Godber ; F. Goesmann ; W. Goetz ; D. Golovin ; F. Gomez Gomez ; J. Gomez-Elvira ; B. Gondet ; S. Gordon ; S. Gorevan ; J. Grant ; J. Griffes ; D. Grinspoon ; J. Grotzinger ; P. Guillemot ; J. Guo ; S. Gupta ; S. Guzewich ; R. Haberle ; D. Halleaux ; B. Hallet ; V. Hamilton ; C. Hardgrove ; D. Harker ; D. Harpold ; A. M. Harri ; K. Harshman ; D. Hassler ; H. Haukka ; A. Hayes ; K. Herkenhoff ; P. Herrera ; S. Hettrich ; E. Heydari ; V. Hipkin ; T. Hoehler ; J. Hollingsworth ; J. Hudgins ; W. Huntress ; J. Hurowitz ; S. Hviid ; K. Iagnemma ; S. Indyk ; G. Israel ; R. Jackson ; S. Jacob ; B. Jakosky ; E. Jensen ; J. K. Jensen ; J. Johnson ; M. Johnson ; S. Johnstone ; A. Jones ; J. Joseph ; I. Jun ; L. Kah ; H. Kahanpaa ; M. Kahre ; N. Karpushkina ; W. Kasprzak ; J. Kauhanen ; L. Keely ; O. Kemppinen ; D. Keymeulen ; M. H. Kim ; K. Kinch ; P. King ; L. Kirkland ; G. Kocurek ; A. Koefoed ; J. Kohler ; O. Kortmann ; A. Kozyrev ; J. Krezoski ; D. Krysak ; R. Kuzmin ; J. L. Lacour ; V. Lafaille ; Y. Langevin ; N. Lanza ; J. Lasue ; S. Le Mouelic ; E. M. Lee ; Q. M. Lee ; D. Lees ; M. Lefavor ; M. Lemmon ; A. Lepinette Malvitte ; R. Leveille ; E. Lewin-Carpintier ; K. Lewis ; S. Li ; L. Lipkaman ; C. Little ; M. Litvak ; E. Lorigny ; G. Lugmair ; A. Lundberg ; E. Lyness ; M. Madsen ; J. Maki ; A. Malakhov ; C. Malespin ; M. Malin ; N. Mangold ; G. Manhes ; H. Manning ; G. Marchand ; M. Marin Jimenez ; C. Martin Garcia ; D. Martin ; M. Martin ; J. Martinez-Frias ; J. Martin-Soler ; F. J. Martin-Torres ; P. Mauchien ; S. Maurice ; A. McAdam ; E. McCartney ; T. McConnochie ; E. McCullough ; I. McEwan ; C. McKay ; S. McLennan ; S. McNair ; N. Melikechi ; P. Y. Meslin ; M. Meyer ; A. Mezzacappa ; H. Miller ; K. Miller ; R. Milliken ; D. Ming ; M. Minitti ; M. Mischna ; I. Mitrofanov ; J. Moersch ; M. Mokrousov ; A. Molina Jurado ; J. Moores ; L. Mora-Sotomayor ; J. M. Morookian ; R. Morris ; S. Morrison ; R. Mueller-Mellin ; J. P. Muller ; G. Munoz Caro ; M. Nachon ; S. Navarro Lopez ; R. Navarro-Gonzalez ; K. Nealson ; A. Nefian ; T. Nelson ; M. Newcombe ; C. Newman ; H. Newsom ; S. Nikiforov ; B. Nixon ; E. Noe Dobrea ; T. Nolan ; D. Oehler ; A. Ollila ; T. Olson ; M. A. de Pablo Hernandez ; A. Paillet ; E. Pallier ; M. Palucis ; T. Parker ; Y. Parot ; K. Patel ; M. Paton ; G. Paulsen ; A. Pavlov ; B. Pavri ; V. Peinado-Gonzalez ; L. Peret ; R. Perez ; G. Perrett ; J. Peterson ; C. Pilorget ; P. Pinet ; J. Pla-Garcia ; I. Plante ; F. Poitrasson ; J. Polkko ; R. Popa ; L. Posiolova ; A. Posner ; I. Pradler ; B. Prats ; V. Prokhorov ; S. W. Purdy ; E. Raaen ; L. Radziemski ; S. Rafkin ; M. Ramos ; E. Rampe ; F. Raulin ; M. Ravine ; G. Reitz ; N. Renno ; M. Rice ; M. Richardson ; F. Robert ; K. Robertson ; J. A. Rodriguez Manfredi ; J. J. Romeral-Planello ; S. Rowland ; D. Rubin ; M. Saccoccio ; A. Salamon ; J. Sandoval ; A. Sanin ; S. A. Sans Fuentes ; L. Saper ; P. Sarrazin ; V. Sautter ; H. Savijarvi ; J. Schieber ; M. Schmidt ; W. Schmidt ; D. Scholes ; M. Schoppers ; S. Schroder ; S. Schwenzer ; E. Sebastian Martinez ; A. Sengstacken ; R. Shterts ; K. Siebach ; T. Siili ; J. Simmonds ; J. B. Sirven ; S. Slavney ; R. Sletten ; M. Smith ; P. Sobron Sanchez ; N. Spanovich ; J. Spray ; S. Squyres ; K. Stack ; F. Stalport ; T. Stein ; N. Stewart ; S. L. Stipp ; K. Stoiber ; E. Stolper ; B. Sucharski ; R. Sullivan ; R. Summons ; D. Sumner ; V. Sun ; K. Supulver ; B. Sutter ; C. Szopa ; F. Tan ; C. Tate ; S. Teinturier ; I. ten Kate ; P. Thomas ; L. Thompson ; R. Tokar ; M. Toplis ; J. Torres Redondo ; M. Trainer ; A. Treiman ; V. Tretyakov ; R. Urqui-O'Callaghan ; J. Van Beek ; T. Van Beek ; S. VanBommel ; D. Vaniman ; A. Varenikov ; A. Vasavada ; P. Vasconcelos ; E. Vicenzi ; A. Vostrukhin ; M. Voytek ; M. Wadhwa ; J. Ward ; E. Weigle ; D. Wellington ; F. Westall ; R. C. Wiens ; M. B. Wilhelm ; A. Williams ; J. Williams ; R. Williams ; R. B. Williams ; M. Wilson ; R. Wimmer-Schweingruber ; M. Wolff ; M. Wong ; J. Wray ; M. Wu ; C. Yana ; A. Yen ; A. Yingst ; C. Zeitlin ; R. Zimdar ; M. P. Zorzano Mier
American Association for the Advancement of Science (AAAS)
Published 2013Staff ViewPublication Date: 2013-07-23Publisher: American Association for the Advancement of Science (AAAS)Print ISSN: 0036-8075Electronic ISSN: 1095-9203Topics: BiologyChemistry and PharmacologyComputer ScienceMedicineNatural Sciences in GeneralPhysicsPublished by: -
3Articles: DFG German National LicensesLitvak, M. E. ; Loreto, F. ; Harley, P. C. ; Sharkey, T. D. ; Monson, R. K.
Oxford, UK : Blackwell Publishing Ltd
Published 1996Staff ViewISSN: 1365-3040Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: BiologyNotes: Isoprene is the primary biogenic hydrocarbon emitted from temperate deciduous forest ecosystems. The effects of varying photon flux density (PFD) and nitrogen growth regimes on rates of isoprene emission and net photosynthesis in potted aspen and white oak trees are reported. In both aspen and oak trees, whether rates were expressed on a leaf area or dry mass basis, (1) growth at higher PFD resulted in significantly higher rates of isoprene emission, than growth at lower PFD, (2) there is a significant positive relationship between isoprene emission rate and leaf nitrogen concentration in both sun and shade trees, and (3) there is a significant positive correlation between isoprene emission rate and photosynthetic rate in both sun and shade trees. The greater capacity for isoprene emission in sun leaves was due to both higher leaf mass per unit area and differences in the biochemical and/or physiological properties that influence isoprene emission. Positive correlations between isoprene emission rate and leaf nitrogen concentration support the existence of mechanisms that link leaf nitrogen status to isoprene synthase activity. Positive correlations between isoprene emission rate and photosynthesis rate support previous hypotheses that isoprene emission plays a role in protecting photosynthetic mechanisms during stress.Type of Medium: Electronic ResourceURL: -
4Articles: DFG German National LicensesStaff View
ISSN: 1365-2109Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, NutritionNotes: Three cryoprotectants (dimethyl sulphoxide, propylene glycol and glycerol) and two diluents (sucrose based and saline based) were mixed (9 parts diluent–1 part cryoprotectant) factorially to produce six extenders that were tested to develop an effective sperm cryopreservation protocol for winter flounder Pseudopleuronectes americanus (Walbaum). Sperm were diluted 1:3 with each extender and frozen by flotation on liquid nitrogen before being submerged and stored for 30 days. Sperm left unfrozen in each extender for 20 min showed no toxic effects on motility. Extenders containing propylene glycol (PG) as cryoprotectant yielded higher post-thaw sperm motilities than those containing dimethyl sulphoxide (DMSO) or glycerol. The sucrose-based diluent performed better than the saline-based diluent when DMSO was used as cryoprotectant, but there were no differences in post-thaw motility between diluents for the other cryoprotectants. Activating sperm with ovarian fluid and sea water instead of sea water alone had no effect on post-thaw motility. In fertilization trials, no differences were observed between any of the extenders and fresh milt when milt, eggs and sea water were left in contact for 1 h. When sperm were forced to compete for eggs by reducing contact time to 20 s, fertilization results followed those of sperm motility rates. Percentage hatch and morphology of larvae at hatching did not differ for eggs fertilized by cryopreserved and fresh sperm. This study represents the first reported successful attempt at cryopreserving winter flounder sperm and should improve gamete and broodstock management protocols for this species.Type of Medium: Electronic ResourceURL: -
5Articles: DFG German National LicensesBaker, D. W. ; Wood, A. M. ; Litvak, M. K. ; Kieffer, J. D.
Oxford, UK; Malden, USA : Blackwell Publishing Ltd/Inc.
Published 2005Staff ViewISSN: 1095-8649Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: BiologyNotes: In vivo experiments were conducted to examine the haematology of juveniles from two relic bony fishes, Atlantic sturgeon Acipenser oxyrhinchus and shortnose sturgeon Acipenser brevirostrum. Oxygen transport characteristics (haematocrit, haemoglobin and mean erythrocytic haemoglobin concentration), ionic composition (Na+, Cl−, K+ and osmolality), metabolite concentration (lactate, cortisol and glucose) and protein content in blood were measured or calculated at rest and during recovery from forced activity. Under resting conditions, plasma osmolality and concentrations of Na+, Cl−, lactate, cortisol and total protein were significantly different between Atlantic and shortnose sturgeon. All other resting variables were not different between species. Following forced activity, plasma lactate levels were significantly higher in both species than at rest. Plasma cortisol levels in both species were only significantly higher 1 h following forced activity compared to resting values. Plasma lactate levels were significantly higher in Atlantic sturgeon than in shortnose sturgeon, but these levels returned to resting levels by 1 h in both species. Cortisol increases were greater in shortnose sturgeon than in Atlantic sturgeon. In general, oxygen transport characteristics, blood glucose, plasma protein and plasma osmolality were not altered by forced activity in either sturgeon species. Overall, both species had reduced responses (i.e. the magnitude of changes in measured variables) to forced activity compared with teleosts.Type of Medium: Electronic ResourceURL: -
6Articles: DFG German National LicensesRideout, R. M. ; Trippel, E. A. ; Litvak, M. K.
Oxford, UK; Malden, USA : Blackwell Science Ltd
Published 2004Staff ViewISSN: 1095-8649Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: BiologyNotes: Semen was collected repeatedly from captive haddock Melanogrammus aeglefinus and the effect of seasonality on various sperm parameters was investigated. No differences in sperm traits were observed for wild and cultured haddock. A highly significant positive relationship existed between spermatocrit and spermatozoa density. A significant increase in mean spermatocrit occurred throughout the spawning season but the amount of variability explained by collection date was low (35·1%) due to variability between males. Each of 10 males sampled repeatedly throughout the spawning season demonstrated an increase in spermatocrit. No relationship existed between spermatocrit and proportion of motile spermatozoa when spermatocrit was ≤70%. Motility was reduced in semen samples with spermatocrits 〉70%. The proportion of spermatozoa that were motile decreased with time since activation. Some motility was still observed after 60 min in sea water (0·1–15·2%) for sperm collected at all times within the spawning season. Of those spermatozoa that were motile, the proportion that exhibited forward swimming motion decreased and the proportion that had only vibratory movement increased with time post-activation. The speed of forward swimming spermatozoa showed no significant relationship with spermatocrit at any time between 0 and 60 min after activation. Swimming speed was negatively related to time since activation, decreasing from 174–240 μm s−1 at 0 min to 80–128 μm s−1 at 60 min after activation.Type of Medium: Electronic ResourceURL: -
7Articles: DFG German National LicensesRideout, R. M. ; Trippel, E. A. ; Litvak, M. K.
Oxford, UK; Malden, USA : Blackwell Science Ltd
Published 2004Staff ViewISSN: 1095-8649Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: BiologyNotes: Three cryoprotectants [dimethyl sulphoxide (DMSO), propylene glycol (PG) and glycerol], two diluents (sucrose- and saline-based), two sperm collection times, two freezing rates and three times between thaw and activation (0, 30 and 60 min) were tested in order to develop a protocol for the cryopreservation of sperm of haddock Melanogrammus aeglefinus and Atlantic cod Gadus morhua. The faster freezing rate resulted in extremely low post-thaw motility in comparison to the slower freezing rate, which was successful for sperm from both gadids. In both cases, the use of PG resulted in significantly higher post-thaw sperm motility-recovery indices than with DMSO or glycerol, which did not differ significantly from one another. Diluent had no effect on post-thaw sperm motility for Atlantic cod or haddock. Sperm collected at the end of the spawning season tended to have reduced post-thaw motility compared to that collected 2 weeks after the start of spawning. A 30 min delay between thaw and activation of haddock and Atlantic cod sperm resulted in a significant decrease in sperm motility. When PG was used as cryoprotectant, sperm motility continued to decrease between 30 and 60 min post-thaw. With DMSO or glycerol as cryoprotectant, motilities were already very low after 30 min post-thaw and did not decrease any further after 60 min. Cryoprotectant, diluent and time between thaw and activation had no effect on mean or maximum sperm swimming speeds for either Atlantic cod or haddock sperm. Fertilization success for haddock eggs, like sperm motility, was higher with PG-frozen sperm than DMSO- or glycerol-frozen sperm. These results constitute the first reported successful cryopreservation of haddock sperm and improve on previous methods used to cryopreserve sperm from Atlantic cod.Type of Medium: Electronic ResourceURL: -
8Articles: DFG German National LicensesStaff View
ISSN: 1095-8649Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: BiologyNotes: Under full–spectrum white light, feeding success of haddock Melanogrammus aeglefinus first feeding larvae, as measured both by proportion of larvae feeding and mean prey consumed, peaked at 1·7-18 μmol s-1 m-2. Feeding was significantly reduced at lower and higher intensities. A similar result was observed for larvae feeding under blue (470 nm) light, with significantly greater feeding success at intermediate light intensity (1·8 μmol s-1 m-2). When different light qualities were compared, larvae had significantly greater feeding success when exposed to blue (470 nm) light than either full-spectrum white or green (530 nm) light. Haddock larvae were capable of prey capture under all light treatments tested, indicating a necessary degree of adaptive flexibility in feeding response. The results are consistent with predisposition of haddock larvae to optimal feeding in a visual environment comparable with open ocean nursery grounds. Information on the impact of light on haddock first feeding can be incorporated into models of larval growth, survival, year-class strength and recruitment, and assist in developing husbandry protocols to maximize larval survival in aquaculture.Type of Medium: Electronic ResourceURL: -
9Articles: DFG German National LicensesRideout, R. M. ; Trippel, E. A. ; Litvak, M. K.
Oxford, UK; Malden, USA : Blackwell Science Ltd/Inc.
Published 2004Staff ViewISSN: 1095-8649Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: BiologyNotes: Paternal effects on haddock Melanogrammus aeglefinus early life history traits were examined by crossing eggs and sperm in a nested design and analysing the progeny at 0, 5 and 10 days post-hatch (dph). The proportion of the variance in early life history traits that was due to paternity was significant for hatching success, larval standard length, myotome height, jaw length and yolk size, but not eye diameter or yolk utilization efficiency. Some morphological traits were influenced more by paternity than maternity. The findings suggest that the importance of males in the early life history success of marine fishes be reconsidered.Type of Medium: Electronic ResourceURL: -
10Articles: DFG German National LicensesStaff View
ISSN: 1095-8649Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: BiologyNotes: Through direct manipulation of yolk sac volume (Vy), in the zebrafish Danio rerio, Vy and offspring size was positively correlated and the relationship was independent of geographical location, parental size or age and, most importantly, parental genetic factors. Larval survivorship, under a non-feeding regime and up until hatch, was not significantly affected by the manipulation. Decreased Vy significantly decreased maximum standard length (LS), maximum body surface area (AB), time to yolk sac absorption, LS and AB at yolk sac absorption, and the LS and AB at starvation. The methodology of Vy adjustment will be useful for the studies of the interaction between early life-history traits and offspring size, egg quality variables and early vertebrate development.Type of Medium: Electronic ResourceURL: -
11Articles: DFG German National LicensesStaff View
ISSN: 0021-9673Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002Topics: Chemistry and PharmacologyType of Medium: Electronic ResourceURL: -
12Articles: DFG German National LicensesStaff View
ISSN: 0378-4347Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002Topics: Chemistry and PharmacologyType of Medium: Electronic ResourceURL: -
13Articles: DFG German National LicensesStaff View
ISSN: 1570-1468Source: Springer Online Journal Archives 1860-2000Topics: Energy, Environment Protection, Nuclear Power EngineeringNotes: Conclusions 1. As a result of seven years of research and experimental work we can recommend chlorinated polyvinyl chloride, ethynolic, and epoxy coatings for corrosion protection of submerged mechanical equipment of river hydraulic structures. The recommended schemes of protective coatings are given in Table 1. On using the data in Table 1 it should be taken into account that primer KhS-010 can be replaced by primer FL-03k or FL-03kk; 3% aluminum powder is added through the layer to varnishes KhSL and KhS-76. 2. The economic expediency of using chlorinated polyvinyl chloride coatings is also confirmed, since the requirements for corrosion protection will be lower than for ethynolic and coatings of Kuzbasslak, although the initial unit cost of the coating will be higher. Table 2 gives the approximate cost (with consideration of assembly operations) of protecting 1 m2 of flat gates or trash racks of the usual channel power station referred to a 30-year service life, and Table 3 gives the unit cost of applying a coating to 1 m2 of surface. The economic efficiency of the coating with the higher initial cost is explained by the fact that the total expenditures for corrosion protection depend on the complexity, volume, and cost of concomitant operations, mainly, on the frequency of necessary restoration of the coatings. The more difficult it is to accomplish these operations and consequently the higher their cost, the more advantageous it is to use the more durable, although more expensive material. When selecting protective materials one should take into account not only the conditions under which the mechanical equipment operates but also the conditions of performing operations on the repair and restoration of the destroyed protective coating, and one should select from the recommended materials and schemes of coatings those which provide a reduction in expenditures for corrosion protection of equipment for a prescribed service life.Type of Medium: Electronic ResourceURL: -
14Articles: DFG German National LicensesStaff View
ISSN: 1434-6052Source: Springer Online Journal Archives 1860-2000Topics: PhysicsNotes: Abstract It is shown that the triangle anomaly can be evaluated in the light-cone gauge and that the result obtained is consistent with the usual covariant one. We use two different procedures: (i) Eliminating the nonphysical fields from the covariant anomalous Ward identity. (ii) Carrying out a chiral transformation on the light-cone Lagrangian. The use of both dimensional and Pauli-Villars regularisations are discussed.Type of Medium: Electronic ResourceURL: -
15Articles: DFG German National LicensesStaff View
ISSN: 1476-4687Source: Nature Archives 1869 - 2009Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsNotes: [Auszug] The optical depth Tg for such materials is given by Tg = phia2NgQ(w,T) where Q(co,jT) = 4coa Im [("£ - l)/(e + 2)]/c is the absorption efficiency, a is the radius of a spherical grain, co/2?u is the radiation frequency, 1 is the complex dielectric constant at a temperature T and N% is the ...Type of Medium: Electronic ResourceURL: -
16Articles: DFG German National LicensesMonson, R. K. ; Harley, P. C. ; Litvak, M. E. ; Wildermuth, M. ; Guenther, A. B. ; Zimmerman, P. R. ; Fall, R.
Springer
Published 1994Staff ViewISSN: 1432-1939Keywords: Seasonal pattern ; Isoprene emission Nitrogen ; Temperature induction ; Biogenic emission inventorySource: Springer Online Journal Archives 1860-2000Topics: BiologyNotes: Abstract Isoprene emission from plants represents one of the principal biospheric controls over the oxidative capacity of the continental troposphere. In the study reported here, the seasonal pattern of isoprene emission, and its underlying determinants, were studied for aspen trees growing in the Rocky Mountains of Colorado. The springtime onset of isoprene emission was delayed for up to 4 weeks following leaf emergence, despite the presence of positive net photosynthesis rates. Maximum isoprene emission rates were reached approximately 6 weeks following leaf emergence. During this initial developmental phase, isoprene emission rates were negatively correlated with leaf nitrogen concentrations. During the autumnal decline in isoprene emission, rates were positively correlated with leaf nitrogen concentration. Given past studies that demonstrate a correlation between leaf nitrogen concentration and isoprene emission rate, we conclude that factors other than the amount of leaf nitrogen determine the early-season initiation of isoprene emission. The late-season decline in isoprene emission rate is interpreted as due to the autumnal breakdown of metabolic machinery and loss of leaf nitrogen. In potted aspen trees, leaves that emerged in February and developed under cool, springtime temperatures did not emit isoprene until 23 days after leaf emergence. Leaves that emrged in July and developed in hot, midsummer temperatures emitted isoprene within 6 days. Leaves that had emerged during the cool spring, and had grown for several weeks without emitting isoprene, could be induced to emit isoprene within 2 h of exposure to 32°C. Continued exposure to warm temperatures resulted in a progressive increase in the isoprene emission rate. Thus, temperature appears to be an important determinant of the early season induction of isoprene emission. The seasonal pattern of isoprene emission was examined in trees growing along an elevational gradient in the Colorado Front Range (1829–2896 m). Trees at different elevations exhibited staggered patterns of bud-break and initiation of photosynthesis and isoprene emission in concert with the staggered onset of warm, springtime temperatures. The springtime induction of isoprene emission could be predicted at each of the three sites as the time after bud break required for cumulative temperatures above 0°C to reach approximately 400 degree days. Seasonal temperature acclimation of isoprene emission rate and photosynthesis rate was not observed. The temperature dependence of isoprene emission rate between 20 and 35°C could be accurately predicted during spring and summer using a single algorithm that describes the Arrhenius relationship of enzyme activity. From these results, it is concluded that the early season pattern of isoprene emission is controlled by prevailing temperature and its interaction with developmental processes. The late-season pattern is determined by controls over leaf nitrogen concentration, especially the depletion of leaf nitrogen during senescence. Following early-season induction, isoprene emission rates correlate with photosynthesis rates. During the season there is little acclimation to temperature, so that seasonal modeling simplifies to a single temperature-response algorithm.Type of Medium: Electronic ResourceURL: -
17Articles: DFG German National LicensesStaff View
ISSN: 1432-1793Source: Springer Online Journal Archives 1860-2000Topics: BiologyNotes: Abstract To examine the impact of development rate on swimming performance, escape response, and morphology, yolk-sac larvae of American plaice (Hippoglossoides platessoides, Fabricius) were reared at two temperatures (5 and 10 °C). Videomicroscopy and silhouette collimation videography were used to examine swimming, escape behaviour, and morphology (standard length, finfold area, and yolk-sac area) of individual larvae. Larvae were examined from 0 d post hatch (dph) to 14 dph for the 5 °C treatment group and from 0 to 6 dph for the 10 °C treatment group (3 August to 17 August 1996). Since larvae were not fed, yolk-sac reserves were essentially exhausted by 14 and 6 dph for the 5 and 10 °C treatment groups, respectively. To control for the effect of testing temperature on behaviour, larvae from each temperature treatment were tested at both 5 and 10 °C. Testing temperature had an effect on some swimming parameters but not on escape response. Swimming performance, escape response, and morphology varied with age, while only morphology and escape response varied with development rate. Morphology and swimming performance, and morphology and escape response were found to be correlated as determined by canonical correlation. This study suggests that both types of swimming behaviours should be examined when developing models of the impacts of predation on the early life history of larval fish.Type of Medium: Electronic ResourceURL: -
18Articles: DFG German National LicensesStaff View
ISSN: 1573-9031Source: Springer Online Journal Archives 1860-2000Topics: Chemistry and PharmacologyType of Medium: Electronic ResourceURL: -
19Articles: DFG German National LicensesStaff View
ISSN: 1572-9559Keywords: rocket plume detection ; submillimeter-wave radiometry ; water vapor rotational linesSource: Springer Online Journal Archives 1860-2000Topics: PhysicsNotes: Abstract The problem of detecting rocket plumes at thermospheric altitudes with satellite-borne submillimeter-wave radiometers is examined theoretically. To estimate the sizes of plume signatures contrasted against a 250-K earth background or in self-emission against the cold sky, a computer program has been developed to predict plume brightness temperatures and optical depths of rotational lines of plume molecular constituents (e.g., H2O) as a function of distance from the nozzle. The methods employed in the computations are described in general terms, and examples are presented to indicate that detectable H2O signatures extending to several thousand nozzle diameters should exist at plume altitudes above 250 km.Type of Medium: Electronic ResourceURL: -
20Articles: DFG German National LicensesDionne, G. F. ; Fitzgerald, J. F. ; Chang, T-S. ; Litvak, M. M. ; Fetterman, H. R.
Springer
Published 1980Staff ViewISSN: 1572-9559Keywords: heterodyne radiometry ; submillimeter-wave spectra ; water vapor rotational lines ; rocket plumesSource: Springer Online Journal Archives 1860-2000Topics: PhysicsNotes: Abstract The intensity and lineshape of the Doppler-broadened 752.033-GHz (211 ← 202) rotational transition of H2O has been studied passively using a high-resolution two-stage heterodyne radiometer with single-sideband system noise temperature of 45,000 K. The purpose of the experiments was to demonstrate the observability at submillimeter wavelengths of a high-altitude rocket plume simulated by a laboratory H2O jet in a vacuum chamber. First-stage mixing was accomplished by means of a GaAs Schottky diode with first local-oscillator power supplied by a CO2-laser pumped formic-acid laser (761.61 GHz), generating and X-band IF signal. Second localoscillator power was provided by a tunable C-band source. One-MHz resolution capability was obtained by means of a 3-GHz waveguide cavity filter with only 9-dB insertion loss. In the H2O jet experiments, the center frequency of the line was determined to within 1 MHz of the previously reported value. A rotational temperature ∼ 75 K, a linewidth ∼5 MHz, and a Doppler shift ∼ 3 MHz (from a 45-degree rotation of the flow direction) were measured with the line-of-sight intersecting the jet axis at a distance downstream of 30 nozzle diameters. These absorption data were ogtained against continuum background radiation sources at temperatures of 1175 and 300 K.Type of Medium: Electronic ResourceURL: