The influence of religious affiliation on surname repetition in marriages in Tiszaszalka, Hungary.

The repeated-pairs of surnames in marriages (RP) approach is applied to the population of Tiszaszalka in north-eastern Hungary. The results indicate that: (1) lineage-like behaviour in mate choice results in population subdivision in both the Catholics and the Protestants of the village; (2) unlike in some other Tiszahat villages, the isonymous and the repeating unions in Tiszaszalka occur in different lineages so, in neither of these subpopulations are isonymous and repeating unions monopolised by a few lineages; (3) religious affilitation influences the mating structure of the population as measured by RP summary scores.     

Low‐dose linearity: The rule or the exception?

In 1976, Crump, Hoel, Langley, and Peto described how almost any dose‐response relationship for carcinogens becomes linear at low doses when background cancers are taken into account. This has been used, by the U.S. Environmental Protection Agency, USEPA, as partial justification for a regulatory posture that assumes low‐dose linearity, as is illustrated by a discussion of regulation of benzene as a carcinogen. The argument depends critically on the assumption that the pollutant and the background proceed by the same biological mechanism. In this paper we show that the same argument applies to noncancer end points also. We discuss the application to a number of situations: reduction in lung function and consequent increase in death rate due to (particulate) air pollution; reduction in IQ and hence (in extreme cases) mental deficiency due to radiation in utero; reduction of sperm count and hence increase in male infertility due to DBCP exposure. We conclude that, although the biological basis for the health effect response is different, in each case low‐dose linearity might arise from the same mathematical effect discussed by Crump et al. (1976). We then examine other situations and toxic end points where low‐dose linearity might apply by the same argument. We urge that biologists and chemists should concentrate efforts on comparing the biological and pharmacokinetic processes that apply to the pollutant and the background. Finally, we discuss some public policy implications of the possibility that low dose linearity may be the rule rather than the exception for environmental exposures.     

Transformation of carbon tetrachloride via sulfur and oxygen substitution by Pseudomonas sp. strain KC.

Pseudomonas sp. strain KC transforms carbon tetrachloride into carbon dioxide and nonvolatile products, without chloroform as an intermediate. To define the pathway for hydrolysis, nonvolatile products were analyzed. Condensation products containing the carbon atom of carbon tetrachloride as carbonyl and thioxo moieties were identified, indicating the intermediacy of phosgene and thiophosgene in the pathway.     

Biliary excretion of synthetic sex steroids in heterozygous and homozygous Gunn rats.

87.9% of a given dose of [³H]Norethisterone ([³H]N) and 76.7% of [³H]Ethinyloestradiol ([³H]EE₂) were excreted in the bile of male heterozygous Gunn rats in 2 hours Similarly, 86.9% of a given dose [³H]N and 84.0% of [³H]EE₂ were excreted in the bile of male homozygous Gunn rats in 2 hours. In both heterozygous and homozygous rats glucuronide conjugates were present. Despite the lesion in UDP-glucuronyltransferase, the homozygous rats is able to conjugate the synthetic steroids apparently normally.     

Ecto-protein kinase activity in rabbit peritoneal polymorphonuclear leucocytes

An ectoprotein kinase activity has been identified on intact rabbit peritoneal polymorphonuclear leucocytes and the time course of phosphate incorporation into proteins has been followed at different ATP levels. Saturation is reached at around 3 mM ATP and the activity is inhibited by p-chloromercuribenzoate. The possibility that the observed protein phosphorylation arises through the action of a membrane ATPase liberating phosphate for transfer into the cell, incorporation into ATP and its utilisation by endogenous kinases, has been excluded by studying both enzymes concomitantly and measuring the rate of [32P]orthophosphate uptake. Lactate dehydrogenase measurements in the extracellular media also exclude the possibility of kinase liberation from lysed cells. Moreover, the pattern of 32P-labelling of polypeptides when intact cells are exposed to [32P]ATP is quite different from that when homogenates are incubated with [32P]ATP or intact cells with [32P]-orthophosphate. We have been unable to demonstrate any cAMP dependency for this ectokinase activity.     

Metabolic cost of motility in planktonic protists: Theoretical considerations on size scaling and swimming speed

The metabolic cost of swimming for planktonic protists is calculated, on theoretical grounds, from a simple model based upon Stokes' law. Energetic expenditure is scaled over both typically encountered size ranges (1–100 µm) and swimming speeds (100–5,000 µm/sec). In agreement with previous estimates for typical flagellates, these estimates generally suggest a low (<1%) cost for motility, related to total metabolic rate of growing cells. However, the cost of motility in small, fast-moving forms, such as some ciliates and flagellates, may be significant (1–10%) and even substantial (10–100%+) for certain species. In accordance with these predictions, many fast-moving ciliates restrict motility to bursts of activity or jumps. In the absence of a reduction in swimming speed or in the frequency of jumps, it is predicted that this relative cost of motility will be significantly increased in starving heterotrophs or light-limited autotrophs, if such cells reduce cell volumes and specific rates of respiration.     

Wall shear stress estimates in coronary artery constrictions.

Wall shear stress estimates from laminar boundary layer theory were found to agree fairly well with the magnitude of shear stress levels along coronary artery constrictions obtained from solutions of the Navier Stokes equations for both steady and pulsatile flow. The relatively simple method can be used for in vivo estimates of wall shear stress in constrictions by using a vessel shape function determined from a coronary angiogram, along with a knowledge of the flow rate.