[Monitoring of dairy cow claw health status in 15 herds using the computerised documentation program Claw Manager and digital parameters]. / Langzeitkontrolle der Klauengesundheit von Milchkühen in 15 Herden mithilfe des Klauenmanagers und digitaler Kennzahlen.

OBJECTIVE: Monitoring of claw health over a defined period using the digital documentation and analysis program Claw Manager. MATERIAL AND METHODS: Data from 679 cows were documented with the Claw Manager during routine functional claw trimming on 15 dairy farms that were visited two or three times. The data of these 33 visits were analysed for the following parameters: prevalence of claw lesions, of their severity scores and of lameness as well as the Cow Claw Score (CCS), the Farm Claw Score (FCS) and the Farm Zone Score (FZS). Their chronological progression was shown using boxplot graphs. RESULTS: Mean prevalence of all lame free cows was 71.9% at visit 1 (max. 95.0%, min. 21.1%) and 72.9% at visit 2 (max. 100.0%, min. 12.6%). The mean prevalence of claw lesions in all 15 herds was 61.8% for heel horn erosion (HHE), followed by white line lesions (WLL, 37.2%), sole haemorrhages (SH, 27.5%), acute and chronic stages of digital dermatitis (DD, 19.7%) and chronic laminitic claws (10.9%). In individual herds HHE (n = 15), WLL (n = 11), SH (n = 10), acute DD (n = 4) and chronic laminitic claws (n = 3) were consistently among the three most frequently observed lesions. A statistically significant improvement was found for the severity scores of the claw lesions of all cows from visit 1 to visit 2. The CCS ranged from 0 (CCS min) to 276 (CCS max), the FCS ranged from 6 to 72. The length of the upper quartiles and the length of the upper whiskers in the boxplot graphs of the CCS values of the herds at the various visits varied widely. The CCS of the cows of ten herds improved significantly from visit 1 to visit 2. Locomotion scores and CCS were significantly correlated on 30 of 33 visits. CONCLUSION: The parameters FCS (median of all CCS values of a herd), length of the upper quartiles, length of the upper whiskers in the boxplot graphs FZS max, the prevalence of lameness and of claw lesions, and their severity scores proved to be very informative for a detailed comparison of claw data of herds over subsequent visits.

Diphenylhexatriene-phosphatidylcholine fluorescence in POPC vesicles: Comparison of the exponential-series and the maximum-entropy methods.

We have investigated the time-resolved fluorescence of diphenylhexatriene (DPH) covalently linked to phosphatidylcholine (PC) in palmitoyloleoylglycerophosphocholine (POPC) vesicles with special consideration of the comparison of two methods for distributional lifetime analysis: the exponential-series method (ESM) and the maximum-entropy method (MEM). Generally, both methods were found to reveal equivalent results on high-quality data. Different are the shapes of the recovered distributions (symmetry and width) as well as the time effort for the numerical analysis.

L-Dityrosine: A time-resolved fluorescence investigation.

We have investigated the time-resolved fluorescence properties ofLL-dityrosine in aqueous solution. Typically, three exponential components were needed to fit the fluorescence pattern adequately, with pure decay terms for the low-intensity, high-energy state (λem = nm) but with a pronounced subnanosecond rise phase for the predominant red-edge fluorescence (λem > 380). Dual fluorescence behavior is indicative of an intramolecular precursorsuccessor pair, i.e., a consecutive intramolecular excited-state reaction. We suggest that this reaction is a torsional motion of the (deprotonated) monoanion along the biphenolic bond. Analysis of the fluorescence anisotropy decay of dityrosine yielded two rotational correlation times, the longer of which is associated with a negative preexponential term. The increase with time in the horizontally polarized component of the intensity decay is interpreted as the result of an electronic rearrangement in the excited state when the successor form of dityrosine is generated. Lifetime distributions of experimental data were probed by an unbiased exponential series method which uses a Tikhonov-type regularization function. The procedure revealed three well-separated groups of lifetimes, the short-lived ensemble forming a formally negative distribution. A photophysical model is introduced which interprets the biexponential decay of dityrosine in terms of overlapping emission signals from the precursor and the successor molecule.