Library

Notes: Abstract Measurements have been made of oxygen consumption rates $$\dot v$$ O2 of 10 specimens of the mesopelagic deep-sea fangtooth fish Anoplogaster cornuta. Determinations were made at 1 atm pressure, at temperatures of 3°, 7°, and 10°C, at dissolved oxygen concentrations ranging from near saturation to zero, with the fish swimming at low, controlled speeds. Weight-specific $$\dot v$$ O2 were uniformly low. They showed Q10's of 2.5 and 1.3, respectively, in the temperature ranges 3° to 7°C, and 7° to 10°C, at dissolved oxygen concentrations above 2 ml (standard temperature and presusure, STP)/1. Measurable $$\dot v$$ O2 continued in these fish at dissolved oxygen concentrations down to the lowest levels detectable with our instruments. At 7°C the average critical oxygen tension (P c ) for the entire group was near 35 mm Hg. However, there is a statistically significant positive slope to the regression line relating $$\dot v$$ O2 to P c for individual fish. The physiological and ecological significance of these results is discussed, particularly with reference to thermal effects and to the basis for survival by A. cornuta in the oxygen minimum layers of the eastern Pacific Ocean.

Notes: Multilayered films with an average concentration of Cu-16 at. % Au and a layering periodicity of 3.31 nm were produced by vapor deposition on sodium chloride substrates. Diffraction studies were carried out at Stanford Synchrotron Radiation Laboratory, thus allowing the observation of up to three orders of satellites, the evolutions of which were measured as a function of annealing time at 515 K. It was found that the first-order satellite intensity decayed nearly exponentially with time, whereas intensities of both second- and third-order satellites decreased very rapidly at first, then increased before decaying exponentially. These results could be explained by following the evolution of satellites during annealing of a one-dimensional modulated system governed by a nonlinear diffusion equation. The diffusivity in this system was assumed to be of the form D0+D1u+D2u2, with u=c−c0, where Di's are the coefficients, c is the concentration, and c0 represents the average composition of the alloy. The nonlinear diffusion equation was solved numerically to obtain one-dimensional concentration profiles at successive annealing times. Satellite amplitudes, obtained by Fourier transforming the concentration profiles, were found to exhibit a remarkable phenomenon: The mth-order satellite amplitude changes its sign (m−1) times before decaying asymptotically to zero. By comparing the evolution of the square of the amplitude with that of the satellite intensities, a set of Di's was determined that produced realistic concentration profiles and reproduced the experimentally evaluated satellite intensities reasonably well.

Notes: In field experiments with spring wheat (Triticum aestivum L., cv. Neepawa), the low rate (0·02 kg ha-1) of chlorsulfuron significantly reduced wild oat control from individual applications of only barban and diclofop-methyl. The high rate (008 kg ha-1) affected wild oat control by all four graminicides, including difenzoquat and flam-prop-methyl. In most cases, the graminicides did not affect the broad-leaved weed control of chlorsulfuran. Overall, a low rate of chlorsulfuron in mixture with graminicides did not reduce wheat yield, whereas a high rate of chlorsulfuron in the mixtures gave a significant yield reduction compared with individual graminicides applied alone. All herbicide treatments increased wheat yield over the control. In the glasshouse, reduction in wild oat control by diclofop-methyl was directly related to the rate of chlorsulfuron added to diclofop-methyl. The effect of 0·02 kg ha-1 chlorsulfuron on control of wild oat was decreased when the rate of diclofop-methyl increased from 0·5 to 0·9 kg ha-1 and was completely eliminated when diclofop-methyl reached 1·1 kg ha-1. Conversely, diclofop-methyl (0·7 and 1·1 kg ha-1) gave some reduction of wild mustard (Sinapis arvensis L.) and redroot pigweed (Amaranthus retrofiexus L.) control by chlorsulfuron (0·01 and 0·02 kg ha-1), even though in some cases diclofop-methyl/chlorsul-furon gave better control of these broad-leaved weeds. In the laboratory, the absorption and translocation of [14C]-diclofop-nieihyl in wild oat seedlings were significantly reduced when chlorsulfuron was added, compared with [14C]-diclo-fop-methyl applied alone.Effet du chlorsulfuron sur l'efficacité et l'effet sur le rendement de quatre graminicidesDans des essais de plein champ sur blé de printemps (Triticuni aestivum L., cv. Neepawa), la faible dose (0, 02 kg ha-1) de chlorsulfuron a réduit significativement l'efficacité d'une application séparée de barbane et de diclofop-methyl. La forte dose (0, 08 kg ha-1) a contrarié la destruction de la folle avoine pour les quatre graminicides dont le difenzoquat et le flamprop-methyl. Dans la plupart des cas, les graminicides n'ont pas eu d'incidence sur la destruction des dicotylédones par le chlorsulfuron. Par ailleurs. une faible dose de chlorsulfuron en mélange avec les graminicides n'a pas réduit le rendement en blé, en revanche, une forte dose de chlorsulfuron en mélange a entrainé une baisse significative de rendement en comparaison des graminicides appliqués seuls. Tous les traitements herbicides ont entrainé un gain de rendement par rapport au témoin non traité. En serre, la réduction d'efficacité sur folle avoine du diclofop-methyl était directement correlée à la dose de chlorsulfuron ajouté. Les effets de 0, 02 kg ha-1 sur la destruction de la folle avoine baissaient quand le niveau de diclofop-methyl augmentait de 0,5 à 0,9 kg ha-1 et étaient complètement éliminés quand la dose de diclofop-methyl atteignait 1, 1 kg ha-1. Par ailleurs, le diclofop-méthyl (0,7 et 1,1 kg ha-1) a réduit l'efficacité du chlorsulfuron (0,01 et 0,02 kg ha-1) sur la sanve (Sinapis arvensis L.) et l'amaranthe réflechie (Amaranthus retroflexus L.) même si dans certains cas l'association diclofop-mélhyl-chtorsulfuron a eu une meilleure efficacité sur ces mauvaises herbes. Au laboratoire, l'ab sorption et la translocation du diclofop-methyl C14 dans les plantules de folle avoine ont été réduites significativement par l'addition de chlor-sulfuron en comparaison du diciofop-méthyl C14 appliqué seul.Wirkung von Chlorsulfuron zusammen mil Vier Graminiziden auf die Unkrautbekämpfung und den Ertrag von WeizenIn Freilandversuehen mit Sommerweizen (Triticum aesttotm L. ‘Neepawa’) verminderie Chlorsulfuron in niedriger Aufwandmenge (0,02 kg ha-1) den Bekämpfungserfolg gegen Flug-Hafer nur bei Barban und Diclofop-menthyl. Die hohe Aufwandmenge (0,08 kg ha-1)beeinträchtigte die Wirkung aller 4 Graminizide, einschliesslich Difenzoquat und Flamprop-methyl. Die Graminizide beeinfiussten die Wirkung von Chlorsulfuron gegen zweikeimblättrige Arten meistens nicht, Der Weizenertrag blieb bei der Mischung der niedrigen Aufwandmenge von Chlorsulfuron mit den Graminiziden unverändert, die hohe Aufwandmenge führte aber in den Mischungen zu einem signifikaten Abfall des Ertrags, vergli-chen mit dem bei Anwendung der Graminizide allein. Mit allen Herbizidbehandlungen wurden gegenüber Unbehandelt höhere Erträge erzielt. Im Gewächshaus war die Wirkung von Diclofopmethyl gegen Flug-Hafer direkt von der zugefügten Menge an Chlorsulfuron abhängig. Der Einfluss von 0,02 kg ha-1 Chlorsulfuron aif die Bekämpfung von Fiug-Hafer nahm ab. wenn die Aufwundmenge von Diclofop-methyl von 0,5 auf 0,9 kg ha-1 gesteigert wurde; bei 1, 1 kg ha-1 Diclofop-methyl war er aufgehoben. Andererseits trat bei 0,7 und 1,1 kg ha-1 Diclofop-methyl eine Minderung der Wirkung von Chlosulfuron (0,01 und 0,02 kg ha-1) gegen Acker-Senf (Sina-psis arvensis L.) und Zurückgekrümmten Fuchsschwanz (Amarenthus retroflexus L.) ein, wenn auch dise Mischung in einigen Fällen gegen dise Arten starker wirkte. Im Labor wurde einc signifikant geringere Absorption und Trans-lokation von 14C-Diclofop-methyl in Keimpflan-zen des Flug-Hafers beobachtet, wenn Chlorsulfuron zugefügt worden war.