Further evidence that in African acacia,white is a warning colour to herbivores: the white pseudo-galls of Vachellia seyal

Pseudo-galls of three East African acacia (Vachellia) species were compared to determine the correlates of gall colour and their potential defensive functions. Although all three species produce white thorns, the pseudo-galls of V. gerrardii and V. drepanolobium are dark coloured. In contrast, pseudo-galls of V. seyal var. fistula are white. Associated with this, they are thin-walled and poorly used by aggressive mutualistic ants. We suggest that this weak functionality is compensated for by the highly visible white colour. This aposematism may also involve mimicry as only the fistula variety of V. seyal has galls and only this variety co-occurs with other Vachellia species that have functional galls. Vachellia seyal seyal does not have pseudo-galls and this variety does not occur with other Vachellia species that have pseudo-galls.     

Fast HPLC for the analysis of oxygen heterocyclic compounds of citrus essential oils.

A fast HPLC method for the determination of the oxygen heterocyclic compounds of citrus essential oils was developed. Five different oils were analyzed under identical conditions, by reversed-phase HPLC with photodiode array detector, for a direct comparison of the composition of their oxygen heterocyclic fraction. Analysis time was 7 min. The oils analyzed were lemon, bergamot, mandarin, sweet orange, and bitter orange. The method developed is good for rapid screening or fingerprinting of these essential oils; a slightly slower method is recommended for higher resolution and better quantitative results.     

The Pelagos Sanctuary for Mediterranean marine mammals

• 1. In February 2002, France, Italy and Monaco agreed to establish an international sanctuary for Mediterranean marine mammals. The resulting Pelagos Sanctuary encompasses over 87500 km² of the north‐western Mediterranean Sea, extending between south‐eastern France, Monaco, north‐western Italy and northern Sardinia, and surrounding Corsica and the Tuscan Archipelago.
• 2. The Pelagos Sanctuary illustrates how the tenets of Marine Protected Area (MPA) design can be reconciled with the dynamic nature of oceanic systems, because its spatial scale was defined by oceanographic and ecological considerations, specifically the location of the Ligurian permanent frontal system.
• 3. By expanding protective measures beyond national waters, the Pelagos Sanctuary also sets a precedent for the implementation of pelagic protected areas in the high seas. The Pelagos Sanctuary will contribute to the conservation of the Mediterranean Sea at two scales: (i) locally, by protecting important cetacean foraging and breeding grounds in the Ligurian Sea, and by providing ‘umbrella’ protection to other marine predators in this area; and (ii) regionally, by empowering other conservation measures, such as the Specially Protected Areas Protocol of the Barcelona Convention and the wider goals of the Agreement on the Conservation of Cetaceans of the Black and Mediterranean Seas (ACCOBAMS).
• 4. However, because few cetacean species are resident within the Sanctuary, their effective long‐term conservation will require large‐scale management and coordinated monitoring throughout the Mediterranean basin.

Copyright © 2007 John Wiley & Sons, Ltd.     

Fetal mummification in a mare

A single mummified fetus was removed from the uterus of a 23-year-old mare that had been bred approximately 30 months previously. The mare had received supplemental progestin therapy for approximately 150 days after ovulation. This case represents the longest recorded occurrence of fetal mummification in the mare. Progestion administration may have contributed to the initial retention of the fetus in the uterus.     

Structural and physiological studies of paraquat-resistant Conyza

Structural and physiological studies were conducted with a population of Conyza bonariensis (L.) Cronq. that segregates into paraquat-resistant and -susceptible biotypes. Leaf disks from resistant seedlings, when incubated on 10 μM paraquat for 24 hr, exhibited little difference from the control disks incubated on H₂O as measured by conductivity change, malondialdehyde formation, or plastid ultrastructure. Leaf disks from the susceptible seedlings incubated on 10^?5M paraquat for 24 hr were uniformly bleached, had elevated malondialdehyde content, and leaked more electrolytes than control disks. Plastids of the susceptible biotype incubated on 10^?5M paraquat for 24 hr were swollen organelles with gross rearrangements of the lamella system. Most of the chloroplasts from the central area of the leaf disk of the resistant biotype incubated on a paraquat solution were structurally normal. Swollen plastids and plastids with twisted lamellae were also noted, although much less frequently. Plastids from the edges of the leaf disks of paraquat-resistant clones were structurally similar to those found throughout the leaf disks in susceptible seedlings. When the size of the leaf disk was increased, paraquat-resistant clones exhibited more “resistance” toward paraquat compared to similar-sized leaf disks of the susceptible seedlings. These data are consistent with the hypothesis that the paraquat-resistant seedlings have an altered uptake and/or compartmentalization of paraquat. Superoxide dismutase isozymes, which were previously considered to be related to paraquat resistance in Conyza, did not correlate with the segregation of paraquat resistance in this population.     

Collaborative study of the analysis of mestranol in combination with norethindrone or norethynodrel

A collaborative study of the analysis of mestranol in combination with norethindrone or norethynodrel by column chromatography and ultraviolet determination is presented. The study consisted of 4 samples which were a commercial norethindrone tablet, a synthetic norethindrone mixture, a commercial norethynodrel tablet, and a synthetic norethynodrel mixture. The samples were analyzed by 13 collaborators. Average mestranol recoveries were 100.4, 99.9, 98.7, and 101.2%, respectively.     

Evaluating foliar nitrogen compounds as indicators of nitrogen status in Prunus persica trees

Mobile nitrogen (N) forms may be better N indicators of the N status of trees than total nitrogen (TN) due to their higher sensitivity to increasing N supply. A field experiment was carried out over a 3-year period to compare foliar concentrations of total N (TN), soluble N (SN), chlorophyll (Minolta SPAD readings), NH₄–N and NO₃–N as indicators of soil N availability in nectarine, Prunus persica L. Batsch, cv. ‘Fantasia’ (grafted on ‘Nemaguard’ peach, P. persica × P. davidiana) trees. Young trees were exposed to a range of fertilizer-N application rates. Based on correlation analysis, the best association between leaf N compounds with soil N supply and trunk diameter and/or fruit yield was obtained with TN and chlorophyll SPAD readings. Leaf concentrations of mobile N compounds (NH₄–N and NO₃–N) increased more than any other N compound under high N supply; however, their inconsistency among years and low leaf concentration difficult their use as N indicators. The optimum foliar TN for growth decreased with tree age, 4.4%, 3.6% and 3.3% in non-bearing 1-year-old trees, non-bearing 2-year-old trees and 3.3 fruit-bearing 3-year-old trees. The optimum SPAD readings were 40 in 2-year-old trees and 42 in 3-year-old trees. Stable N compounds (TN and chlorophyll SPAD) could be used to N diagnosis in the zone of N deficiency, and soluble N compounds (NH₄–N and NO₃–N) to diagnoses N excess.