Recent developments in the chemistry of sandalwood odorants

Natural sandalwood oil, a unique and valuable ingredient in fine perfumery, has been the focus of scientific interest for many years. Due to its scarcity and its high price, the search for novel synthetic raw materials imitating the characteristic odor profile of sandalwood oil is as challenging as ever. In this context, the preparation of the novel sandalwood odorants 26, 33, and 39 will be discussed, including their sensory properties and structure-odor relationship.     

Feeding responses of the red fox (<Emphasis Type="Italic">Vulpes vulpes</Emphasis>) to different wild rabbit (<Emphasis Type="Italic">Oryctolagus cuniculus</Emphasis>) densities: a regional approach

We investigate the feeding responses of the red fox (Vulpes vulpes) at a regional scale to different densities of European wild rabbit (Oryctolagus cuniculus) in central–southern Spain. Rabbit abundance indices were obtained in 86 localities during summer 2002. The diet of the fox was studied by analysis of 114 scats collected in 47 of these localities. The feeding response of the fox was examined by a representation of the dry weight percent of rabbit in the diet as a function of the abundance of rabbits; this used data only from those localities where at least 3 scats were collected (70 fox scats from 18 localities). We evaluated the relationship between rabbit abundance and the diversity of the diet of the fox. The feeding patterns of red foxes approximated to Holling’s type III functional response, typical of opportunistic predators. There was a negative relationship between the diversity of the fox’s diet and the abundance of rabbits. Therefore, the fox apparently behaves as a facultative predator, feeding on rabbits when they are abundant and shifting to other prey (and hence a more diverse diet) when rabbits are scarce. These findings are the first step towards understanding the potential role of red foxes in regulating rabbit populations in central–southern Spain.     

Molecular phylogenetic relationship of Epinephelus based on sequences of mtDNA Cty b

The mtDNA Cyt b gene was sequenced partially for Variola louti of Serranidae, Epinephelinae and seven endemic species of groupers—Epinephelus awoara, E. brunneus, E. coioides, E. longispinis, E. sexfasciatus, E. spilotoceps and E. tauvina in China. The seven endemic species and other seven foreign species of groupers—E. aeneus, E. caninus, E. drummondhayi, E. haifensis, E. labriformis, E. marginatus and E. multinotatus from the GenBank were combined and analysed as ingroup, while Variola louti was used as outgroup. We compared the 420 bp sequences of Cyt b among the 15 species and constructed two types of molecular phylogenetic trees with maximum parsimony method (MP) and neighbor-joining method (NJ) respectively. The results were as follows: (1) As to the base composition of mtDNA Cyt b sequence (402 bp) of 14 species of Epinephelus, the content of (A + T) was 53.6%, higher than that of (G + C) (46.4%). The transition/transversion ratio was 4.78 with no mutation saturation. (2) The cluster relationships between E. awoara and E. sexfasciatus, E. coioides and E. tauvina, E. longispinis and E. spilotoceps were consistent with phenotypes in taxonomy. (3) In the phylogenetic tree, the species in the Atlantic Ocean were associated closely with those in the Pacific Ocean, which suggested that the Cyt b sequences of Epinephelus were highly conserved. This may be attributed to the coordinate evolution. (4) In wel1-bred mating or heredity management, mating Epinephelus of the same branch should be avoided. It is likely to be an effective way to mate the species of the Atlantic Ocean with those of the Pacific Ocean to improve the inheritance species. __________ Translated from Acta Hydrobiologica Sinica, 2006, 30(4): 432–438 [译自: 水生生物学报]     

Aboveground biomass dynamics of subalpine old-growth forest in the upper reach of the Minjiang River

Biomass estimation of old-growth forests in the upper Minjiang River (UMR) is important in quantifying carbon (C) sequestration and C sink size because majority of the natural forests in UMR are mature or over-mature. Based on the forest resource data from 27 fixed sampling plots that have been surveyed consecutively, the dynamics of the aboveground biomass density (AGBD) were characterized by the allometric relationships, and the space-time variations of the C sink size in the sub-alpine old-growth forests of UMR were explored. Our results showed that 1) the net increase in AGBD was (27.311 ± 15.580) Mg·hm^?2 and the mean annual growth rate and mean annual death rate were (1.930 ± 1.091) and (2.271 ± 1.424) Mg·hm^?2·a^?1 during 1988–2002, respectively. 2) The aboveground biomass (AGB) largely depended on the growth and death rates of the trees with different diameters at the breast height (DBH) classes and the recruitment rate from one DBH class to another as well. The largest increment component of AGB came from the DBH class of 20 to 40 cm, whereas the minimum increment component of AGB was above 80 cm in DBH. The net negative increment of AGB occurred at DBH classes of 40–60 and 60–80 cm. 3) There were space-time variations of AGB in the alpine old-growth forests, indicated by AGB changing over time in the same sampling plot and varying among the locations or plots during the same sampling period. These variations were not only reflected in numerical value but also in positive or negative biomass increment.     

What biogeography is: a place for process

The search for understanding of the past and present processes that have and/or continue to generate observed biotic distribution patterns substantially involves historical reconstruction based on present patterns (both phylogenetic and geographical). How this should be undertaken has been a cause for major debate over many decades. Residual patterns do not always provide explicit pointers to the causal processes, and in addition to applying our understanding of earth history, we need also to carefully explore the implications of contemporary processes as a means for unravelling pattern. Some biogeographers assert that earth and life evolve together, but knowledge of distributions and ecologies indicate that this is sometimes true and sometimes false. Just as general patterns may sometimes indicate a commonality of the means that generated the patterns so, too, do observable processes sometimes indicate commonalities. Vicariance and dispersal are fundamental attributes of biotic distributions. Phylogeography has the potential to assist us in determining which of these mechanisms has generated observable patterns.     

Molecular Characterization of Cyst Nematode Species (Heterodera spp.) from the Mediterranean Basin using RFLPs and Sequences of ITS-rDNA

Fifteen populations of cyst‐forming nematodes belonging to 11 known and one unidentified species collected in countries bordering the Mediterranean Sea were studied using polymerase chain reaction restriction fragment length polymorphism (PCR–RFLP) and internal transcribed spacer (ITS)‐rDNA sequences. RFLP profiles generated by the restriction enzymes AluI, AvaI, Bsh1236I, HaeIII, Hin6I, MvaI, PstI and RsaI are presented for Heterodera carotae, H. ciceri, H. fici, H. filipjevi, H. goettingiana, H. hordecalis, H. humuli, H. mediterranea, H. ripae and H. schachtii. Molecular data support the first detection of H. filipjevi from wheat in Italy and H. ripae from nettle in Greece. A relative high level of sequence divergence between populations of H. hordecalis was observed. This suggests that two species might presently be grouped under this taxon. The phylogenetic relationship between the Mediterranean cyst‐forming nematode species is analysed based on the ITS‐rDNA sequences.     

Maternal care and foal social relationships in a herd of Sorraia horses: Influence of maternal rank and experience

The influence of maternal rank and experience on patterns of maternal care and social relationships of foals were investigated in a managed herd of Sorraia horses, Equus caballus. Social interactions and spatial relationships of 13 foals (seven females and six males) born to seven mares were examined from birth to 10 months of life, within the three major periods of foal development. Conflict over suckling between dam and foal was not generally affected by rank and experience, but higher-ranking mothers allowed more suckling during late lactation than lower-ranking mothers. Foals of higher-ranking mares spent more time in proximity to the mother during socialization. Maternal rank and experience did not significantly affect maternal protectiveness, foal independence from the mother or the development of affiliative relationships between foals and group members. Foals of higher-ranking mares received lower frequencies of aggression from other horses only in the first month of life. Dominance relationships among foals depended mainly on aggressiveness and were not associated with maternal rank. The large variability in maternal behaviour, the absence of a significant association between maternal rank and body condition at parturition and the stable social environment within this herd may partly account for the reported results.     

Functional insight for beta-glucuronidase in Escherichia coli and Staphylococcus sp. RLH1

Glycosyl hydrolases hydrolyze the glycosidic bond either in carbohydrates or between carbohydrate and non-carbohydrate moiety. The beta-glucuronidase (beta D-glucuronoside glucuronosohydrolase; EC 3.2.1.31) enzyme belongs to the family-2 glycosyl hydrolase. The E. coli borne beta-glucuronidase gene (uidA) was devised as a gene fusion marker in plant genetic transformation experiments. Recent plant transformation vectors contain a novel beta-glucuronidase (gusA) derived from Staphylococcus sp. RLH1 for E. coli uidA. It is known to have a ten fold higher sensitivity compared to E. coli beta-glucuronidase. The functional superiority of Staphylococcus (gusA) over E. coli (uidA) activity is not fully known. The comparison of secondary structural elements among them revealed an increased percentage of random coils in Staphylococcus beta-glucuronidase. The 3D model of gusA shows catalytic site residues 396Glu, 508Glu and 471Tyr of gusA in loop regions. Accessible surface area (ASA) calculations on the 3D model showed increased ASA for active site residues in Staphylococcus beta-glucuronidase. Increased random coil, the presence of catalytic residues in loops, greater solvent accessibility of active residues and increased charged residues in gusA of Staphylococcus might facilitate interaction with the solvent. This hypothesizes the enhanced catalytic activity of beta-glucuronidase in Staphylococcus sp. RLH1 compared to that in E. coli.