The influence of snow on lynx and coyote movements: does morphology affect behavior?

Summary We studied sympatric lynx (Lynx canadensis) and coyotes (Canis latrans) to assess how morphological disadvantages to locomotion over snow affected movement patterns. Both species are of similar size and mass, but the feet of lynx are much larger, and coyotes were found to have 4.1–8.8 times the foot-load (ratio of body mass to foot area) of lynx. This resulted in greater mean sinking depths of coyote limbs, although the magnitude of the difference was less than that in foot-load. Coyotes exhibited stronger use of behavioral patterns that reduced negative effects of snow on movements. Coyotes were most abundant at low elevations where snow was shallow, whereas lynx were mostly at higher elevations. Coyotes also used areas at both elevations where snow was shallower than average, while lynx used areas where snow was deeper. further, both species used travel routes where snow was shallower than it was near the track. Coyotes traveled on harder snow and used trails more frequently, thereby tending to reduce sinking depths to those similar to lynx. The behavioral repertoire of coyotes reduced the morphological advantage of large feet possessed by lynx; however, overall sinking depths were still greater in coyotes. Snowshoe hares (Lepus americanus) were the main prey of both species, and their foot-load was less than that of either predator. Hare kills by coyotes occurred after fewer bounds than did those by lynx, and the large difference between foot-loads of both species of predators may have forced coyotes to ambush rather than chase hares, as did lynx.     

Isolation and characterization of sporulation-specific promoters in the yeast Saccharomyces cerevisiae

A library of random yeast genomic DNA:lacZ fusions has been constructed using an episomal yeast-Escherichia coli shuttle vector (pCS1). Plasmid pCS1 requires insertion of a promoter and an in frame ATG codon upstream of its resident truncated lacZ gene to regulate expression in yeast. Yeast genomic DNA fragments of 4-6 kb were generated by partial digestion with Sau3A and ligated into the unique BamHI site of plasmid pCS1 to generate a library of 5 x 10(4) individual E. coli transformants. This library was screened to identify promoter-lacZ fusions that were expressed uniquely during sporulation. Of 342 yeast transformants that exhibited beta-galactosidase activity, two were found to express the lacZ gene in a sporulation-specific manner. This paper presents the characterization of two genomic yeast DNA fragments containing promoters that control lacZ expression during the sporulation process. Expression from the promoter present in plasmid pJC18 occurred from 11-21 hours into the sporulation process, while the promoter in plasmid pJC217 was active from 4-14 hours. Staining of nuclear DNA to correlate nuclear morphology with timing of gene expression showed when each of these promoters was active in terms of the morphological stages of sporulation.     

A general method for biological parameter estimation

Summary A general observer-based estimator method is developed and applied for process modelling and monitoring. This parameter estimation technique was successfully applied to a L-lysine fermentation process. It was a useful tool to detect the effect of major culture conditions on cell growth and product synthesis. It can also be used for the development of adaptive optimal control schemes.     

Substituted piperidin-2-one biphenyltetrazoles as angiotensin II antagonists

A novel series of substituted piperidine-2-ones has been identified as antagonists of angiotensin II. These compounds showed high affinity for the receptor in bovine adrenal cortex binding assays with IC₅₀'s as low as 20nM. They are potent inhibitors of angiotensin II induced contractions in rabbit aortic rings, with pA₂ values as high as 9. A number of these compounds are also orally active as antihypertensives in spontaneously hypertensive rat preparations.     

Maturation-related changes in mass and elemental contents of secretory granules as measured by electron-microprobe

Summary The relationship between granule density, protein content, and Ca and S contents were studied in two secretory granule fractions, from parotid glands of the rat, previously shown to constitute different stages in granule maturation. The density of the lighter fraction was between 1.133 and 1.142 g/ml, while that of the heavier fraction was greater than 1.142 g/ml. The mean protein content of the denser granules was 12% greater than that of the lighter granules (P<0.03), while the dry-mass elemental concentrations in the two granule fractions were unchanged. These results indicate that protein is added to granules during the maturation process (presumably by vesicular traffic), and that the resulting increase in granule density is not driven simply by decrease in water content and/or increased concentrations of inorganic Ca or S in the granules. The elemental concentration values also indicate that the diffusible elements permeate the granule membrane during the fractionation procedures.     

American anthropologists looking through Taiwanese culture

Conclusion Anthropologists have too often supported — in their words, in their presences, and in their deeds — the paternalistic claims of rulers suppressing the very cultures they want to study. Much anthropological work legitimates substitution of the language of Beijing for Hakka and Holo, justifies ignoring Taiwanese culture, and subordinates consideration of its specific features to writing about Chinese civilization, just as Taiwanese are economically and politically subordinated to the ethnic minority dictatorship which still rules Taiwan under the fiction of being the government of China. The China that Arthur Wolf and others serve in return for support of their research from what purports to be the Republic of China is an egregious, but unfortunately not unique, example.Stephen O. Murray is with El Instituto Obregón, San Francisco, California. Keelung Hong is with the Cancer Research Institute, University of California, San Francisco.As is normal in anthropology, except for Taiwan, native terms are romanized in the native language (in the first author's recording of the second author's Daidiong idiolect, without indication of the extremely intricate tone differentia), not in the official language of the ethnic oligarchy ruling Taiwan (Beijinghua). Mainland place names are rendered in pinyin. We have followed the convention of treating Chinese and Taiwanese personal names as two words, because books are catalogued with such names. If personal names are considered as two words (an imposition of the hoary dogma that words in Sino-Tibetan languages are monosyllabic), it seems to us that both words should be capitalized. For Taiwanese placenames, we have not separated syllables by dashes or by spaces.     

Habitat selection and subsequent reproductive success in the beaugregory damselfish

Synopsis Male beaugregory damselfish,Stegastes leucostictus, were provided with three types of artificial breeding structures to determine if they change habitats based on past or future reproductive payoffs. All three site types quickly lured males away from their natural sites. In comparison to those living on natural sites, those using artificial sites were less likely to move to different areas and had a higher reproductive success. When given no choice, male reproductive success was correlated to structural type. A second experiment provided males with an additional structure after using the intermediate quality type for 2 months. Males would often initially use both sites but would eventually shift their spawning activity to the new site if it was of the same quality or better than the old one. However, males would not move if the new site was of inferior quality. When given a new site identical to the initial one, approximately half of the males shifted to the new site. There was no evidence that reproductive performance influenced a male's decision to use a new site.