Some comparative studies of two alkaline phosphatases fromAspergillus niger

Summary Alkaline phosphatases (ALP I and ALP II), isolated and purified fromAspergillus niger exhibited broad specificity towards a wide variety of substrates, and consistently ALP II was more active than ALP I. It is possible that the difference in levels of activity of the 2 enzymes may be of physiological importance in the mycelia ofA. niger.     

The range of life in amber: significance and implications in DNA studies

A survey of the major fossiliferous amber deposits is provided, including ages and various categories of life forms reported from each. The frequence of occurrence of the major groups of plants and animals in these amber deposits is also given. Thus far, DNA from four insect and one plant species has been extracted from amber fossils. In the case of the stingless bee in Dominican amber, evidence of reproducibility is provided, since two independent laboratories isolated DNA from six or more different specimens of the same insect.Amber sources for DNA studies are listed together with their advantages and disadvantages. The important points are the availability of desired pieces, the proper identification of the fossil, verification of the amber deposit, the cost involved, and the feasibility of causing damage to the specimen. The availability of several types of amber (Mexican, Dominican, Baltic, Chinese, Canadian, Siberian and Lebanese) at four major sources (academic collections, commercial dealers, private collections and amber mines) is discussed. The scientific implications of obtaining DNA from amber inclusions are presented.     

Postsynaptic long-term potentiation follows coupling of dendritic glutamate application and synaptic activation

Dendritic depolarization, which seems to be involved in the induction of long-term potentiation (LTP), was elicited by localized glutamate application. When paired to low frequency synaptic activation in the same area, the subsequent changes had features in common with LTP, expressed as an increased probability of firing and shorter spike latency. The EPSP was not significantly increased.     

Inhibitory effect of antiproteoglycan serum on the biosynthesis of proteochondroitin sulfate in calf rib cartilage in vitro

Summary Incubation of calf rib cartilage slices with antiproteoglycan serum elevates CO₂-production, but inhibits biosynthesis of proteochondroitinsulfate and of total protein. Absorbing antiserum with proteoglycan abolishes these effects.Acknowledgment. This work was supported by grant K1 193/9 and 10 from the Deutsche Forschungsgemeinschaft.     

A medium to demonstrate the ligninolytic activity of some fungi

Zusammenfassung Es wird hier eine neue Methode angeführt, um die holzauflösende Fähigkeit einiger Pilze zu bestimmen. Ein milchiges, homogenes Agarmedium wird hergestellt, indem man kugelgemahlenes Buchensägemehl als hauptsächliche Kohlenstoffquelle benutzt. Wenn man in dieses Medium bestimmte holzzerstörende Pilze einpflanzt, wird sowohl ihre holzspaltende als auch ihre zellulosezerstörende Wirkung dadurch gezeigt, dass das Medium unter dem Wurzelgeflecht sich aufklärt.     

The beta-subunit of follicle-stimulating hormone is deleted in patients with aniridia and Wilms' tumour, allowing a further definition of the WAGR locus

One in 10,000 children develops Wilms' tumour, an embryonal malignancy of the kidney. Although most Wilms' tumours are sporadic, a genetic predisposition is associated with aniridia, genito-urinary malformations and mental retardation (the WAGR syndrome). Patients with this syndrome typically exhibit constitutional deletions involving band p13 of one chromosome 11 homologue. It is likely that these deletions overlap a cluster of separate but closely linked genes that control the development of the kidney, iris and urogenital tract (the WAGR complex). A discrete aniridia locus, in particular, has been defined within this chromosomal segment by a reciprocal translocation, transmitted through three generations, which interrupts 11p13. In addition, the specific loss of chromosome 11p alleles in sporadic Wilms' tumours has been demonstrated, suggesting that the WAGR complex includes a recessive oncogene, analogous to the retinoblastoma locus on chromosome 13. In WAGR patients, the inherited 11p deletion is thought to represent the first of two events required for the initiation of a Wilms' tumour, as suggested by Knudson from epidemiological data. We have now isolated the deleted chromosomes 11 from four WAGR patients in hamster-human somatic cell hybrids, and have tested genomic DNA from the hybrids with chromosome 11-specific probes. We show that 4 of 31 markers are deleted in at least one patient, but that of these markers, only the gene encoding the beta-subunit of follicle-stimulating hormone (FSHB) is deleted in all four patients. Our results demonstrate close physical linkage between FSHB and the WAGR locus, suggest a gene order for the four deleted markers and exclude other markers tested from this region. In hybrids prepared from a balanced translocation carrier with familial aniridia, the four markers segregate into proximal and distal groups. The translocation breakpoint, which identifies the position of the aniridia gene on 11p, is immediately proximal to FSHB, in the interval between FSHB and the catalase gene.     

Prediction in the two‐way random‐effect model with heteroskedasticity

In this paper we extend Taub (1979) approach for prediction in the context of the variance components model. The extension obtained is based on the two‐way random‐effect model with heteroskedasticity. Prediction functions are then obtained in three heteroskedasticity cases (heteroskedasticity on the individual term , heteroskedasticity on the composite term ?_it, and heteroskedasticity on the temporal term ). Copyright © 2008 John Wiley & Sons, Ltd.