Parasites of non-native freshwater fishes introduced into england and wales suggest enemy release and parasite acquisition

When non-native species are introduced into a new range, their parasites can also be introduced, with these potentially spilling-over into native hosts. However, in general, evidence suggests that a high proportion of their native parasites are lost during introduction and infections by some new parasites from the native range might occur, potentially resulting in parasite spill-back to native species. These processes were investigated here using parasite surveys and literature review on seven non-native freshwater fishes introduced into England and Wales. Comparison of the mean numbers of parasite species and genera per population for each fish species England andWaleswith their native ranges revealed\9 % of the native parasite fauna were present in their populations in England and Wales. There was no evidence suggesting these introduced parasites had spilled over into sympatric native fishes. The non-native fishes did acquire parasites following their introduction, providing potential for parasite spill-back to sympatric fishes, and resulted in non-significant differences in overall mean numbers of parasites per populations between the two ranges. Through this acquisition, the non-native fishes also had mean numbers of parasite species and genera per population that were not significantly different to sympatric native fishes. Thus, the non-native fishes in England and Wales showed evidence of enemy release, acquired new parasites following introduction providing potential for spill-back, but showed no evidence of parasite spill-over

Determination of collisional line broadening coefficients with femtosecond time-resolved CARS

The potential of femtosecond time-resolved CARS for the determination of J-dependent line broadening coefficients is demonstrated. With the well-developed femtosecond technique the line broadening coefficients of the H2 Q-branch ro-vibrational transitions are measured in pure H2 and in H2 + He and H2 + N2 mixtures. The results for pure H2 show excellent agreement with the values obtained by other groups using high-resolution CARS in the wavenumber domain. The dependence of the experimental broadening on perturber density also shows good agreement with the behavior of broadening found in the literature: a linear dependence in the case of hydrogen and helium as perturber and explicit nonlinear behavior in the case of nitrogen. The role of inhomogeneous broadening in time domain CARS is discussed. Copyright (C) 2002 John Wiley Sons, Ltd

Determination of collisional line broadening coefficients with femtosecond time-resolved CARS

The potential of femtosecond time-resolved CARS for the determination of J-dependent line broadening coefficients is demonstrated. With the well-developed femtosecond technique the line broadening coefficients of the H2 Q-branch ro-vibrational transitions are measured in pure H2 and in H2 + He and H2 + N2 mixtures. The results for pure H2 show excellent agreement with the values obtained by other groups using high-resolution CARS in the wavenumber domain. The dependence of the experimental broadening on perturber density also shows good agreement with the behavior of broadening found in the literature: a linear dependence in the case of hydrogen and helium as perturber and explicit nonlinear behavior in the case of nitrogen. The role of inhomogeneous broadening in time domain CARS is discussed. Copyright (C) 2002 John Wiley Sons, Ltd

Quantification of lycopene in the processed tomato-based products by means of the light-emitting diode (LED) and compact photoacoustic (PA) detector

The combined use of a high power light emitting diode (LED) and the compact photoacoustic (PA) detector offers the possibility for a rapid (no extraction needed), accurate (precision 1.5%) and inexpensive quantification of lycopene in different products derived from the thermally processed tomatoes. The concentration of lycopene in selected products ranges from a few mg to several tens mg per 100 g fresh weight. The HPLC was used as the well established reference method