The status of Abbott's Babbler in Borneo

We reviewed the occurrence of Abbott's Babbler Trichastoma abbotti on Borneo as a first step towards understanding why this species, which is common in most of its range, is so rare on the island. We were able to find only 21 documented Bornean records, most of which derived from areas of scrub habitat at low altitudes, especially near the coast

A review of the status and distribution of the Bornean Bristlehead

We compiled all documented records of Bornean Bristlehead Pityriasis gymnocephata to determine what is known about the life-history and distribution of this enigmatic species. Pityriasis is a relict cracticid, related to the Australian magpies and butcherbirds. It is a highly social species and widespread throughout Borneo in forests below 1000m elevation, but rarely encountered

A NEW CHONDRODYSTROPHIC MUTANT IN MICE : Electron Microscopy of Normal and Abnormal Chondrogenesis

The occurrence of a new mutation affecting cartilage and bone in mice is reported. The gene is lethal, shows autosomal recessive inheritance, and has high penetrance. It is not allelic to shorthead and probably not to phocomelia or achondroplasia. It results in a foreshortened face, cleft palate, defective trachea, and shortened long bones with flared metaphyses. Chondrocytes of epiphyseal cartilage from the mutant are not aligned in columns, and there is a decrease in the usual staining of the cartilage matrix. Electron microscope observations show large, wide collagen fibrils with "native" banding in the matrix of mutant cartilage, which are not present in normal cartilage. Possible explanations for the expression of this genetic disorder of cartilage development are put forward

A biochemical study of the marine annelid worm, Thoracophelia mucronata: Its food, biochromes and carotenoid metabolism

Comparative biochemical studies of numerous marine invertebrates and fishes have indicated that the majority of such species so far examined selectively assimilate and store xanthophyllic or allied oxygenated carotenoids rather than carotenes, when consuming food containing both types of pigment. In some forms there is complete exclusion of carotenes, e.g., in several fishes, in the sea mussel (Mytilus californianus), in at least three brittle stars, and in some color-variants of the anemone Metridium senile. Some asteroid echinoderms store carotenes, but in far lower concentrations than xanthophylls, while four species of echinoids appear to assimilate relatively greater quantities of carotenes (Fox, Updegraff and Novelli, 1944)

Lewis Base Catalysis Promoted Nucleophilic Substitutions - Recent Advances and Future Directions

Nucleophilic substitutions (SN) account for the most essential and frequently applied chemical transformations. SN‐reactions allow forging C–C, C–O, C–N and C–Cl bonds, for example, from natural abundant starting materials such as alcohols and carboxylic acids. Products of SN‐reactions are ubiquitous and find inter alia applications as pharmaceuticals, plant protection agents and polymers. However, conventional SN‐type approaches are restricted frequently by the necessity of hazardous reagents and by‐products, a poor waste‐balance and therefore sustainability and high levels of costs, which especially impedes application in large scale synthesis. In order to provide solutions to these limitations, the development of novel catalytic methods for SN‐transformations has evolved into a flourishing and reviving area of research. The current review enables an overview of modern strategies for catalytic nucleophilic substitutions, presents as main topic the state‐of‐the‐art with respect to SN‐methods that are promoted by Lewis bases and points out potential future directions for further innovations

Mathematical Analysis and Optimization of Infiltration Processes

A variety of infiltration techniques can be used to fabricate solid materials, particularly composites. In general these processes can be described with at least one time dependent partial differential equation describing the evolution of the solid phase, coupled to one or more partial differential equations describing mass transport through a porous structure. This paper presents a detailed mathematical analysis of a relatively simple set of equations which is used to describe chemical vapor infiltration. The results demonstrate that the process is controlled by only two parameters, alpha and beta. The optimization problem associated with minimizing the infiltration time is also considered. Allowing alpha and beta to vary with time leads to significant reductions in the infiltration time, compared with the conventional case where alpha and beta are treated as constants

The Mean and Scatter of the Velocity Dispersion-Optical Richness Relation for maxBCG Galaxy Clusters

The distribution of galaxies in position and velocity around the centers of galaxy clusters encodes important information about cluster mass and structure. Using the maxBCG galaxy cluster catalog identified from imaging data obtained in the Sloan Digital Sky Survey, we study the BCG-galaxy velocity correlation function. By modeling its non-Gaussianity, we measure the mean and scatter in velocity dispersion at fixed richness. The mean velocity dispersion increases from 202+/-10 km/s for small groups to more than 854+/-102 km/s for large clusters. We show the scatter to be at most 40.5+/-3.5%, declining to 14.9+/-9.4% in the richest bins. We test our methods in the C4 cluster catalog, a spectroscopic cluster catalog produced from the Sloan Digital Sky Survey DR2 spectroscopic sample, and in mock galaxy catalogs constructed from N-body simulations. Our methods are robust, measuring the scatter to well within one-sigma of the true value, and the mean to within 10%, in the mock catalogs. By convolving the scatter in velocity dispersion at fixed richness with the observed richness space density function, we measure the velocity dispersion function of the maxBCG galaxy clusters. Although velocity dispersion and richness do not form a true mass-observable relation, the relationship between velocity dispersion and mass is theoretically well characterized and has low scatter. Thus our results provide a key link between theory and observations up to the velocity bias between dark matter and galaxies.Comment: 25 pages, 15 figures, 2 tables, published in Ap