Phylogeny and biogeography of the Vitrinidae (Gastropoda: Stylommatophora)

The phylogeny of the Vitrinidae is reconstructed in a cladistic analysis based on characters of the genitalia, the copulation behaviour and the radula. The genera with an atrial stimulator turned out to be the earliest branches of the Vitrinidae, whereas the genera with a glandula amatoria form a monophyletic, taxonomically apomorphic group. The differences between the proposed phylogeny and previous hypotheses are discussed. The ancestral areas of the Vitrinidae and its sister group, the limacoid slugs Boettgerillidae–Limacidae–Agriolimacidae, are estimated using weighted ancestral area analysis. The Vitrinidae and the limacoid slugs might have originated by a vicariance event between Central Europe and the Near East. © 2002 The Linnean Society of London. Zoological Journal of the Linnean Society , 2002, 134 , 347–358.     

Latitudinal variation in population structure of wintering Pacific Black Brant

ABSTRACT.   Latitudinal variation in population structure during the winter has been reported in many migratory birds, but has been documented in few species of waterfowl. Variation in environmental and social conditions at wintering sites can potentially influence the population dynamics of differential migrants. We examined latitudinal variation in sex and age classes of wintering Pacific Black Brant ( Branta bernicla nigricans ). Brant are distributed along a wide latitudinal gradient from Alaska to Mexico during the winter. Accordingly, migration distances for brant using different wintering locations are highly variable and winter settlement patterns are likely associated with a spatially variable food resource. We used resightings of brant banded in southwestern Alaska to examine sex and age ratios of birds wintering at Boundary Bay in British Columbia, and at San Quintin Bay, Ojo de Liebre Lagoon, and San Ignacio Lagoon in Baja California from 1998 to 2000. Sex ratios were similar among wintering locations for adults and were consistent with the mating strategy of geese. The distribution of juveniles varied among wintering areas, with greater proportions of juveniles observed at northern (San Quintin Bay and Ojo de Liebre Lagoon) than at southern (San Ignacio Lagoon) locations in Baja California. We suggest that age-related variation in the winter distribution of Pacific Black Brant is mediated by variation in productivity among individuals at different wintering locations and by social interactions among wintering family groups.     

Stock and parental effects on embryonic and early larval development of winter flounder Pseudopleuronectes americanus (Walbaum)

A hierarchical breeding design was used to determine if winter flounder Pseudopleuronectes americanus embryos and yolk-sac larvae sired by Georges Bank males developed and grew larger than fish sired by Passamaquoddy Bay males, and to examine parental contributions to variations in fertilization success, time to 50% hatch, hatch success and larval morphological development. Significant stock effects were detected for time to hatch and larval development. Eggs fertilized by Passamaquoddy Bay males reached 50% hatch significantly earlier than eggs fertilized by Georges Bank males. Larvae sired by Georges Bank males were significantly larger during larval development for four of the six traits measured at 12 days post-hatch: head depth, jaw length, myotome height and body area. Embryo and larval development were strongly influenced by maternal contributions; there were significant maternal variance components for the majority of the variables measured. Paternal variance components were significant for fertilization success, time to hatch, larval jaw length and larval head depth, however, they acted principally through parental interactions. This information has important implications for the long-term sustainable development of winter flounder for aquaculture purposes as well as for understanding winter flounder genetic variation in the wild.     

Habitat quality,population dynamics,and group composition in Colobus Monkeys (Colobus guereza)

Data from an Ethiopian population of Colobus guerezashow that territory size is fixed by the high density of the population. Groups undergo fission when their size results in fewer than 10 trees per individual within the group’s territory. The daughter groups produced by fission emigrate into suboptimal habitat, which acts as a demographic sink. Comparative analyses using data from other East African populations demonstrate that mean territory size is inversely related to population density and that density, in turn, is a function of the size of the forest block. Since both group size and reproductive rates can be shown to be positively correlated with type of forest, it is concluded that this relationship reflects the fact that local population densities reach their ceiling more rapidly in small forest blocks because the animals’ access to alternative territories is limited. The number of males in a colobus group is shown to be a function of the number of females in it. Multimale groups have lower reproductive rates than one-male groups, probably because the stress generated by competition among the males causes temporary infertility among the females.     

Zinc,copper, selenium,and glutathione peroxidase in blood of 11-yr-old dunedin,New Zealand children

Blood was obtained from 564 11-yr-old children who had participated since birth in a multidisciplinary health and development study. Serum zinc concentration did not differ between the boys and the girls (mean±SD: 91=17 μg/100 mL,n=453). Five-6% of serum zinc values were low; although there was a weak correlation with height, none of the boys with low values were below the 10th percentile for height for this group. Serum copper concentration (112±24 μg/100 mL,n=454) was unrelated to sex, height, weight, body mass index, socioeconomic status (SES), or iron status. Blood selenium concentration (49±10 ng/mL,n=564) was lower than previously reported for Dunedin children; it was higher in children in the lower SES categories. The data represent normal values for healthy, 11-yr-old NZ children.     

Application of PIXE analysis to the study of the regional distribution of trace elements in normal human brain

A particle-induced X-ray emission (PIXE) analysis method is presented, which allows measurement of eight elements (i.e., K, Ca, Mn, Fe, Cu, Zn, Se, and Rb) in human brain samples of only a few mg dry weight. The precision and accuracy of the method were investigated by analyzing animal brain matter with both PIXE and instrumental neutron activation analysis (INAA). The method was applied to measure the 8 elements in 46 different regions of 3 human brains. The sections analyzed originated from either the left or the right cerebral hemisphere, brain stem, and cerebellum. For one of the brains, sections were also analyzed from 26 corresponding regions of both hemispheres. For all elements, similar concentrations were found in the corresponding areas of the left and right sides of the brain. The concentrations (in μg/g dry weight) of the elements K, Fe, Cu, Zn, Se, and Rb were consistently higher in cortical structures than in white matter. Deep nuclei and brain stem, which have a mixed composition, showed intermediate values for K, Zn, Se, and Rb. A hierarchical cluster analysis indicated that the various brain regions clustered into two large groups, one comprising gray and mixed matter regions and the other, white and mixed matter brain areas.     

In vitro reactions of sugarcane (Saccharum SP.) plantlets inoculated with 2 strains of Xanthomonas albilineans (Ashby) Dowson

The symptoms of the leaf scald disease can be reproduced in vitro through the inoculation of sugarcane tissue culture plantlets. The pathogen is detected in the inoculated plantlet and is maintained at the surface of the base of the plantlets grown in vitro. Two strains of X. albilineans belonging to different serovars and lysovars reacted like pathotypes. The importance of the plant incubation temperature is clearly demonstrated. Further, in vitro the disease goes through the same phase of latency as in the field.