Territorial behaviour in southern impala rams (Aepyceros melampus Lichtenstein)

The role of territoriality was investigated by studying 25 impala rams at a reserve in the Waterberg region of South Africa (23°45′S, 28°23′E). Mean territorial tenure was 67.25 days (range 23–99), with a mean territory size of 21.0 ± 11.27 ha, compared with home ranges of 34.1 ± 9.03 ha for territorial rams and 58.8 ± 33.35 ha for bachelor rams, using the fixed kernel method. Territory boundaries remained constant, whilst the area surrounding important features such as water holes, appears to be neutral in terms of territoriality. The rut, as evidenced from peaks in chasing and roaring, lasted for 2 months from 10 April to 10 June 2001, with intensified behaviour including matings observed from 16 May to 4 June 2001. Territorial rams chase and roar more than bachelors. Flehmen and display behaviours are performed by all rams, whilst fights and other reproductive behaviours are generally rare. Bachelors browse more than territorial rams. Only bachelors spar and allogroom, and orally groom themselves more than territorial rams.     

Characterisation of yeast phosphoglycerate kinase modified by mutagenesis at residue 21.

Site-directed mutagenesis has been used to produce mutant forms of yeast phosphoglycerate kinase in which the conserved active-site residue, Arg21, has been replaced by a methionine or a lysine. Kinetic results obtained using these mutant enzymes show that their Km for both 3-phospho-D-glycerate and ATP are significantly different from those recorded for the wild-type enzyme. The Vmax for the lysine mutant is reduced by a factor of two from that of the wild-type enzyme whereas the Vmax for the methionine mutant is reduced more than sevenfold. A very clean electron-density-difference map shows little, if any, evidence of a structural change associated with the C-terminal domain, although resonances in the NMR spectra associated with the ATP-binding site (C-terminal domain) are also affected by the mutation as one might expect from the kinetic results. The NMR data show that binding at both the 3-phospho-D-glycerate and the non-productive ATP-binding site (associated with the N-terminal domain) are affected in the mutant in a way which is different to that associated with the wild-type enzyme. These results, taken together with the X-ray and kinetic data, indicate that the non-productive ATP-binding site and the activating anion-binding site are both associated with the basic patch region of yeast phosphoglycerate kinase.     

A POPULAR INDONESIAN PREACHER: THE SIGNIFICANCE OF AA GYMNASTIAR

Aa Gymnastiar (Gym) is a popular Indonesian Muslim preacher who seems to be now at the pinnacle of his fame. He regularly gives advice to the head of state and to ministers and yet at the same time his approach to Islam appeals to all sections of the national Muslim community. His is a familiar face in newspaper columns and above all on television screens; Aa Gym has a masterful command of the media. This article describes and accounts for his popularity and discusses it in terms of continuity and change in the rise and decline of Muslim celebrities in Indonesia. It points out the difference between Gym and some obvious forerunners such as the scholar Hamka, and stresses that the nature of Gym's appeal is new in as much as he does not come from within the circle of traditional families of Muslim ulama . He seems to draw his information as much from secular sources of self-help manuals as from books of Sufi wisdom. Although very popular and influential among the general circle of believers, he is regarded with some suspicion by those who criticize his sufistic leanings and lack of an orthodox Muslim education. The article concludes by arguing that Gym and his approach to the implementation of Muslim precepts is more representative of the nature of Islam in Indonesia today than the activities of terrorists.     

New selective and differential medium for Vibrio cholerae and Vibrio vulnificus

Thiosulfate-citrate-bile salts-sucrose agar has been routinely used for the isolation of pathogenic vibrios, although its selectivity for Vibrio cholerae and Vibrio vulnificus is inadequate. Therefore, a new plating medium, cellobiose-polymyxin B-colistin agar, was developed for the isolation of these two species. Cellobiose-polymyxin B-colistin agar demonstrated a significant advantage over other media designed for the isolation or differentiation of vibrios: of both the 136 strains representing 19 Vibrio species and the marine isolates of the genera Pseudomonas, Flavobacterium, and Photobacterium, only V. vulnificus and V. cholerae were able to grow. Furthermore, the fermentation of cellobiose by V. vulnificus allowed for the easy differentiation of these two species. This medium offers significant potential as a selective and differential medium for these two pathogenic vibrios.     

Unique patterns of androgen regulation of the expression of two genes in murine kidney

The kidneys of androgen stimulated mice exhibit a hypertrophic response but no hyperplasia or concomitant DNA replication. Androgens increase the expression of several genes in mouse kidney. The response of the beta-glucuronidase gene to testosterone in this tissue is characterized by a 1-2 day lag and relatively slow induction kinetics. The gene coding for kidney androgen-regulated protein (KAP) exhibits quite a different response to the hormone when compared on the basis of initial response to a given dose, dose required to produce maximal response, and apparent sensitivity to low levels of androgen-receptor complexes in renal nuclei. The analysis of the accumulation of the mRNAs produced by these two genes suggests that gene-specific differential sensitivity to androgen receptor complexes governs the development of the cellular male phenotype in this tissue.     

Amino acid-dependent transport of sugars by Fusobacterium nucleatum ATCC 10953.

Resting cells of Fusobacterium nucleatum 10953 (grown previously in a medium containing glucose) failed to accumulate glucose under aerobic or anaerobic conditions. However, the addition of glutamic acid, lysine, or histidine to anaerobic suspensions of cells caused the immediate and rapid accumulation of glucose. Except for the amino acid-dependent transport of galactose and fructose (the latter being transported at approximately one-third the rate of glucose), no other sugars tested were accumulated by the resting cells. Amino acid-dependent uptake of sugar(s) by F. nucleatum was abolished by exposure of cells to air, and under aerobic conditions the rates of fermentation of glutamic acid and lysine were less than 15% of the rates determined anaerobically. The energy necessary for active transport of the sugars (acetyl phosphate and ATP) is derived from the anaerobic fermentation of glutamic acid, lysine, or histidine. Competition studies revealed that glucose and galactose were mutual and exclusive inhibitors of transport, and it is suggested that the two sugars (Km = 14 microM) are translocated via a common carrier. The products of amino acid-dependent sugar transport were recovered from resting cells as ethanol-precipitable, high-molecular-weight polymers. Polymer formation by F. nucleatum, during growth in medium containing glucose or galactose, was confirmed by electron microscopy.     

Age-related changes in oxidized proteins

We have previously described the oxidative inactivation of several key metabolic enzymes by a variety of mixed function oxidation systems. Because many of the enzymes which are inactivated have been shown by others to accumulate as inactive or less active forms during cellular aging, we have examined the levels of oxidatively modified proteins in two model systems used for studies on aging. The results show that levels of oxidatively modified proteins increase with age in circulating erythrocytes, and this change is correlated with the loss of marker enzyme activity. Our studies also show that in cultured fibroblasts from normal donors the levels of oxidatively modified proteins increase only after the age of 60. However, the levels of oxidatively modified proteins in fibroblasts from individuals with progeria or Werner's syndrome are significantly higher than age-matched controls. Moreover, treatment of glucose-6-phosphate dehydrogenase with a mixed function oxidation system leads to oxidative modification and increased heat lability of the enzyme. Taken together these results suggest that loss of functional enzyme activity and increased heat lability of enzymes during aging may be due in part to oxidative modification by mixed function oxidation systems.