Experimental Evidence for Phonemic Contrasts in a Nonhuman Vocal System

The ability to generate new meaning by rearranging combinations of meaningless sounds is a fundamental component of language. Although animal vocalizations often comprise combinations of meaningless acoustic elements, evidence that rearranging such combinations generates functionally distinct meaning is lacking. Here, we provide evidence for this basic ability in calls of the chestnut-crowned babbler (Pomatostomus ruficeps), a highly cooperative bird of the Australian arid zone. Using acoustic analyses, natural observations, and a series of controlled playback experiments, we demonstrate that this species uses the same acoustic elements (A and B) in different arrangements (AB or BAB) to create two functionally distinct vocalizations. Specifically, the addition or omission of a contextually meaningless acoustic element at a single position generates a phoneme-like contrast that is sufficient to distinguish the meaning between the two calls. Our results indicate that the capacity to rearrange meaningless sounds in order to create new signals occurs outside of humans. We suggest that phonemic contrasts represent a rudimentary form of phoneme structure and a potential early step towards the generative phonemic system of human language.     

The effect of X-irradiation on cell cycle progression and chromatid aberrations in stimulated human lymphocytes using cohort analysis studies.

Stage sensitivity for the production of chromatid-type aberrations and mitotic delay has been investigated in a stimulated human lymphocyte population, following an absorbed dose of 1.5 Gy 250 kVp X-rays. BrdU replication banding was used to obtain a fine analysis of the cell cycle and to permit cohort analysis. Fluctuations in yield with sample time were found for all aberration categories, but these could not be related simply to either the developmental stage of the cells at time of exposure, or to the time-to-run to metaphase. In general G2 and late S cells had higher aberration yields than early S and pre S cell populations. Mitotic delay and perturbation at this dose extends to all sub-phases of S and is as great, if not greater, in the earliest S cells as it is in G2.     

Induction of sister chromatid exchanges (SCE) in G0 lymphocytes by plutonium-238 alpha-particles

Irradiation of human G0 lymphocytes with plutonium-238 alpha-particles and X-rays was performed to investigate the production of sister chromatid exchanges (SCE). Alpha-particles produce a significant increase in SCE and this elevation is more significant when separated lymphocytes are irradiated. X-ray irradiation did not induce any significant increase in SCE. Therefore the relative biological effectiveness (RBE) for the induction of SCE by alpha-particles in this system is undefined and effectively infinite.     

Phenotypic characterization of Adig null mice suggests roles for adipogenin in the regulation of fat mass accrual and leptin secretion

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Host specificity of filamentous, segmented microorganisms adherent to the small bowel epithelium in mice and rats

Germfree rats and mice were given by gavage samples of ileal homogenates prepared from conventional rats and mice. Filamentous, segmented procaryotes adhered to the small bowel epithelium in the ex-germfree mice only when the homogenate was made from mouse bowel and in the ex-germfree rats only when the inoculum came from rats. Thus, the filamentous microorganisms are host animal specific.     

Blood group complexity: the Pm locus in Peromyscus maniculatus1

The Pm blood group system in Peromyscus maniculatus was originally described by Rasmussen as consisting of two co-dominant alleles, Pm^A and Pm^B, responsible for the antigenic characteristics A and B. This paper describes two additional antisera, anti-C and anti-X, which expand this system and show it to be serologically complex. Anti-X is comprised of antibodies directed against at least two antigenic characteristics X‘ and X“. Four and possibly six alleles are described by the four antisera. Different subspecies exhibit different spectra of alleles at the Pm locus. A segregation distortion is evidenced.