Short-term climatic trends affect the temporal variability of macroinvertebrates in California 'Mediterranean' streams

1. Long‐term studies in ecology are essential for understanding natural variability and in interpreting responses to disturbances and human perturbations. We assessed the long‐term variability, stability and persistence of macroinvertebrate communities by analysing data from three regions in northern California with a mediterranean‐climate. During the study period, precipitation either increased or decreased, and extreme drought events occurred in each region. 2. Temporal trends in precipitation resulted in shifts from ‘dry‐year’ communities, dominated by taxa adapted to no or low flow, to ‘wet‐year’ communities dominated by taxa adapted to high flows. The abundance of chironomid larvae was an important driver of community change. Directional change in community composition occurred at all sites and was correlated with precipitation patterns, with more dramatic change occurring in smaller streams. 3. All communities exhibited high to moderate persistence (defined by the presence/absence of a species) and moderate to low stability (defined by changes in abundance) over the study period. Stability and persistence were correlated with climatic variation (precipitation and El Niño Southern Oscillation) and stream size. Stability and persistence increased as a result of drought in small streams (first‐order) but decreased in larger streams (second‐ and third‐order). Communities from the dry season were less stable than those from the wet‐season. 4. This study demonstrates the importance of long‐term studies in capturing the effects of and recovery from rare events, such as the prolonged and extreme droughts considered here.     

Lice of farm animals in Libya

Abstract. This first report on the lice of farm animals in Libya lists a total of fifteen species, as follows: Haematopinus quadripertusus and Linognathus vituli from cattle, Bovicola ovis, Linognathus pedalis, L.afrlcanus and L.ovillus from sheep, L.stenopsis, L.africanus and Bovicola caprae from goats. Poultry harboured Lipeurus caponis, L.heterographus, Menacanthus stramineus, Menopon gallinae, Goniocotes gallinae, Goniodes gigas and G.dissimilis.     

EFFECTS OF VISUAL MASKING TECHNIQUES ON THE INTENSITY RATING OF SWEETNESS OF GELATINS AND LEMONADES1

Visual masking techniques are frequently used to prevent panelists from discriminating among samples on the basis of color differences, only. The purpose of the study was to determine if these conditions alter the responses of the judges. Raspberry gelatins sweetened with 9, 10, 14 and 16% sucrose, respectively, and lemonades sweetened with 8, 10, 12 and 14% sucrose, respectively, were rated for perceived sweetness intensity using four different visual masking conditions (red lights, red glasses, dyes and blindfolds) and a white light and clear glasses control condition. Most of the visual masking techniques did not significantly affect the sweetness scores for the gelatins or lemonades. The one exception was the dye condition for the lemonades where the color (turquoise) probably affected the results.