A common method of tracking humeral motion involves securing a thermoplastic cuff to the humerus with an electromagnetic sensor attached. The data on the accuracy of this technique are limited. This ...study addressed two questions: (a) How similar are surface and bone-fixed measurements of 3-D humeral rotations? (b) How similar are surface and bone-fixed measurements of 3-D humeral translations? Electromagnetic motion sensors were secured to a bone-fixed external humeral fixator, a surface humeral cuff, and the skin over the sternum and scapular acromion process. The 3-D data were collected during successive slow velocity (10–20°/second) repetitions of humeral active-assisted scapular plane abduction, sagittal plane flexion, and internal/external rotation with the arm adducted. Root mean square errors of surface measures compared to bone-fixed angular and translational values were calculated, and paired
t
-tests were computed between the two methods. Root mean square errors for humeral rotations ranged from 1° (1%) for humeral elevation during scapular plane abduction to 7.5° (9%) for humeral internal/external rotation. Peak errors were under-representations of 5.7° for internal/external rotation during scapular plane abduction and 15.6° for internal rotation with the arm adducted at the side. Average translation errors ranged from 0.1 to 2.1 mm. Data from this study suggest that dynamic measurement of humeral motion with a surface humeral cuff sensor can be performed for certain slow velocity motions with root mean square errors less than 8°. Caution is called for when interpreting internal/external rotation values, which were underrepresented. Results may vary with one’s age, weight, or general physical condition, with different velocities of movement, or with different movements.
Four isolates of Fusarium graminearum differing in aggressiveness and a susceptible and a resistant spring wheat cultivar (Picolo and Frontana, respectively) were analysed under controlled conditions ...after ear inoculation. The disease incidence was assessed and the deoxynivalenol (DON) content of ears was analysed by reversed-phase HPLC during the entire pathogenesis. After harvest, the DON content of rachis, chaff and kernels was separately analysed and yield parameters (e.g., thousand-kernel dry weight and kernel diameter distribution) were measured. The DON content and disease incidence differed significantly among the F. graminearum isolates. The isolate with the lowest DON content also showed the lowest aggressiveness. The maximum rise of the DON content in relation to disease severity occurred as early as three days post inoculation, indicating that DON may enhance fungal aggressiveness. As even the low toxin producer is still aggressive, additional factors may play a role in aggressiveness. The correlation among DON content and disease incidence was weaker during the later stages of pathogenesis. Wheat kernels contained less DON than rachis and chaff and the pathogen-induced yield reduction proved to be a reliable parameter for assessing fungal aggressiveness. The resistant cultivar Frontana showed a lower disease incidence and contained less DON than the susceptible cultivar Picolo. As the infection rates differed less at the later stages of pathogenesis, DON may play its role especially during the earlier and mid stages of pathogenesis. The possible role of DON as virulence factor and causal connections are discussed. Vier F. graminearum-lsolate unterschiedlicher Aggressivität bzw. zwei Sommerweizensorten verschiedener Anfälligkeit (Picolo und Frontana) wurden nach künstlichen Ähren-Inokulationen unter kontrollierten Bedingungen untersucht. Die visuelle Bonitur der Symptome und die Messung des Desoxynivalenol-Gehalts (DON) von Gesamtähren mit Hilfe von reversed-phase HPLC (UV-Detektion) erfolgte simultan und kontinuierlich während der gesamten Pathogenese. Zur Ernte wurden die Ähren in Spindel, Spelzen und Körner aufgeteilt, getrennt auf den DON-Gehalt untersucht und Ertragsparameter erhoben (z. B. Tausendkornmasse, Korngrößenverteilung). Zwischen den F.-graminearum-Isolaten traten signifikante Unterschiede sowohl in der Befallshäufigkeit als auch im DON-Gehalt der Weizenähren auf. Das Isolat mit dem geringsten DON-Gehalt wies auch die niedrigste Aggressivität auf. Dies könnte als ein Hinweis auf eine Rolle von DON als Aggressivitätsfaktor interpretiert werden. Hierfür spricht auch, dass schon drei Tage nach Inokulation die maximale Zunahme des DON-Gehalts bezogen auf die Befallsstärke (Δ DONadjusted) erreicht wurde. Da der geringe Toxinbildner immer noch vergleichsweise aggressiv ist, ist eine Beteiligung weiterer Aggressivitätsfaktoren wahrscheinlich. Außerdem war die Korrelation zwischen DON-Gehalt und Befall in frühen und mittleren Stadien der Pathogenese enger als am Versuchsende. Die Körner enthielten weniger DON als die Spindeln oder Spelzen und die pathogeninduzierte Ertragsreduktion erwies sich als guter Parameter zur Bemessung der Aggressivität eines Isolats. Die Sorte Frontana zeigte einen geringeren Befall und DON-Gehalt als Picolo. Da die Unterschiede im Befall beider Sorten am Ende des Versuchs geringer werden, ist anzunehmen, dass DON am ehesten in frühen und mittleren Stadien der Pathogenese eine Rolle im Wirt-Pathogen-System spielt. Die Bedeutung von DON als Aggressivitätsfaktor und mögliche kausale Zusammenhänge werden diskutiert.
31 Fusarium graminearum isolates were tested to determine the extent of their in vitro mycotoxin production and their aggressiveness and the results from both tests were correlated. Rice samples ...inoculated with the different F. graminearum isolates were analysed for the trichothecene mycotoxins deoxynivalenol (DON), acetyl-deoxynivalenol (ADON; 3- and 15-acetyl-DON together), nivalenol (NIV) and acetyl-nivalenol (ANIV) using reversed-phase HPLC. The aggressiveness test was carried out on wheat seedlings inoculated with F. graminearum at the sprout base. DON and ADON were produced by all F. graminearum isolates; neither NIV nor ANIV were identified in any. The toxin amounts varied substantially, e. g. from 0.1 to 812 mg kg⁻¹ for DON. DON and ADON production correlated closely. A high variability was also shown regarding the extent of aggressiveness whereby the necrotic area on the sprout base varied vertically from 5.8 to 22.0 mm. The data on toxin production and on the aggressiveness of the 31 isolates tested showed no correlation whether or not the toxins were applied individually or as a total. 31 Fusarium graminearum-Isolate wurden auf ihre Mykotoxin-Bildung in vitro und Aggressivität getestet und die Ergebnisse beider Untersuchungen miteinander korreliert. Hierzu wurden Reisproben mit diesen F. graminearum-Isolaten inokuliert und mit reversed-phase HPLC auf die Trichothecene Desoxynivalenol (DON), Acetyl-Desoxynivalenol (ADON; 3- und 15-ADON zusammen), Nivalenol (NIV) und Acetyl-Nivalenol (ANIV) analysiert. Im Aggressivitätstest wurden Weizen-Keimlinge an der Sprossbasis mit F. graminearum-Isolaten inokuliert. DON und ADON wurden von allen Isolaten gebildet, NIV und ANIV konnten bei keinem der Isolate nachgewiesen werden. Die gebildete Toxin-Menge variierte beträchtlich, z. B. von 0.1 bis 812 mg kg⁻¹ für DON. Die DON- und ADON-Bildung zeigten eine enge Korrelation. Ebenso zeigte die Aggressivität der Isolate eine hohe Variabilität mit beispielsweise einer vertikalen Verbräunungsausdehnung an der Sprossbasis von 5.8 bis 22.0 mm. Die Ergebnisse der Toxinproduktion (DON, ADON), weder einzeln noch als Summe, und der Aggressivität der 31 Isolate korrelierten nicht miteinander.
We demonstrate a novel 2D MOT beam source for cold 6Li atoms. The source is side-loaded from an oven operated at temperatures in the range 600<T<700 K. The performance is analyzed by loading the ...atoms into a 3D MOT located 220 mm downstream from the source. The maximum recapture rate of ~10^9 /s is obtained for T=700 K and results in a total of up to 10^10 trapped atoms. The recaptured fraction is estimated to be 30(10)% and limited by beam divergence. The most-probable velocity in the beam (alpha_z) is varied from 18 to 70 m/s by increasing the intensity of a push beam. The source is quite monochromatic with a full-width at half maximum velocity spread of 11 m/s at alpha_z=36 m/s, demonstrating that side-loading completely eliminates beam contamination by hot vapor from the oven. We identify depletion of the low-velocity tail of the oven flux as the limiting loss mechanism. Our approach is suitable for other atomic species.
We study Bragg scattering at 1D optical lattices. Cold atoms are confined by
the optical dipole force at the antinodes of a standing wave generated inside a
laser-driven high-finesse cavity. The ...atoms arrange themselves into a chain of
pancake-shaped layers located at the antinodes of the standing wave. Laser
light incident on this chain is partially Bragg-reflected. We observe an
angular dependence of this Bragg reflection which is different to what is known
from crystalline solids. In solids the scattering layers can be taken to be
infinitely spread (3D limit). This is not generally true for an optical lattice
consistent of a 1D linear chain of point-like scattering sites. By an explicit
structure factor calculation we derive a generalized Bragg condition, which is
valid in the intermediate regime. This enables us to determine the aspect ratio
of the atomic lattice from the angular dependance of the Bragg scattered light.
We report on the observation of Bragg scattering at 1D atomic lattices. Cold
atoms are confined by optical dipole forces at the antinodes of a standing wave
generated by the two counter-propagating ...modes of a laser-driven high-finesse
ring cavity. By heterodyning the Bragg-scattered light with a reference beam,
we obtain detailed information on phase shifts imparted by the Bragg scattering
process. Being deep in the Lamb-Dicke regime, the scattered light is not
broadened by the motion of individual atoms. In contrast, we have detected
signatures of global translatory motion of the atomic grating.
We study the widths of interspecies Feshbach resonances in a mixture of the fermionic quantum gases 6Li and 40K. We develop a model to calculate the width and position of all available Feshbach ...resonances for a system. Using the model we select the optimal resonance to study the 6Li/40K mixture. Experimentally, we obtain the asymmetric Fano lineshape of the interspecies elastic cross section by measuring the distillation rate of 6Li atoms from a potassium-rich 6Li/40K mixture as a function of magnetic field. This provides us with the first experimental determination of the width of a resonance in this mixture, Delta B=1.5(5) G. Our results offer good perspectives for the observation of universal crossover physics using this mass-imbalanced fermionic mixture.
We study Bragg scattering at 1D optical lattices. Cold atoms are confined by the optical dipole force at the antinodes of a standing wave generated inside a laser-driven high-finesse cavity. The ...atoms arrange themselves into a chain of pancake-shaped layers located at the antinodes of the standing wave. Laser light incident on this chain is partially Bragg-reflected. We observe an angular dependence of this Bragg reflection which is different to what is known from crystalline solids. In solids the scattering layers can be taken to be infinitely spread (3D limit). This is not generally true for an optical lattice consistent of a 1D linear chain of point-like scattering sites. By an explicit structure factor calculation we derive a generalized Bragg condition, which is valid in the intermediate regime. This enables us to determine the aspect ratio of the atomic lattice from the angular dependance of the Bragg scattered light.
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