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To improve the erythritol productivity ofPenicillium sp. KJ81, mutants were obtained using UV irradiation and NTG treatment. Among these mutants,Penicillium sp. KJ-UV29 revealed no morphological changes, yet was superior to the wild strain in the following three points: (1)Penicillium sp. KJ-UV29 produced more erythritol than the wild strain under the same conditions, (2) no foam was produced during cultivation,
unlike the wild strain, and (3) the mutant produced a significantly lower amount of glycerol.Penicillium sp KJ-UV29 produced as much as 15.1 g/L of erythritol, whereas the wild-typePenicillium sp. KJ-UV29 produced as much as 15.1 g/L of erythritol, whereas the wild-typePenicillium sp. KJ81 only produced 11.7 g/L.Penicillium sp. KJ-UV29 only generated 6.1 g/L of glycerol, compared to 19.4 g/L produced by the wild strain. When investigating the
optimal culture conditions for erythritol production by the mutant strainPenicillium sp. KJ-UV29, sucrose was idetified as the most effective carbon source, and the mutant was even able to produce erythritol
in a 70% sucrose-containing medium, although a 30% sucrose medium exhibited the highest productivity. The production of erythritol
byPenicillium sp. KJ-UV29 was also significantly increased by the addition of ammonium carbonate, potassium nitrate, and sodium nitrate.
Accordingly, under optimal conditions,Penicillium sp. KJ-UV29 produced 45.2 g/L of erythritol in a medium containing 30% sucrose, 0.5% yeast extract, 0.5% (NH4)2C2O4 0.1% NaNO3, and 0.01% FeSO4 with 1 vvm aeration and 200 rpm agitation at 37°C for 7 days in a 5-L jar fermentor. 相似文献
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P L Walker 《American journal of physical anthropology》1989,80(3):313-323
Crania from the Channel Island area of southern California were examined for evidence of traumatic injuries. Well-healed depressed fractures in the outer table of the cranial vault are common in skeletal remains from the northern Channel Islands (18.56% n = 598) but rare in those from the mainland coast (7.5% n = 146). This prevalence of traumatic injuries among the islanders may be a result of intense competition over resources in a geographically circumscribed environment. The frequency of cranial injuries increases significantly between the early and late prehistoric periods on the Channel Islands. This temporal variation appears to reflect changes in patterns of violence associated with population growth and environmental instability. 相似文献
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S Pfeiffer 《American journal of physical anthropology》1984,65(2):181-189
Pathological skeletal remains from the Uxbridge Ossuary (1490 +/- 80 A.D., N = 457) are classified into four broad categories: trauma, congenital disability, tumor, and infection. Traumatic injuries are relatively common (fractures in 5-9.4% of total), considering the date and subsistence pattern of the population. Congenital disabilities and tumors are rare, affecting approximately 2% of the population. Nonspecific periosteitis and osteitis affect 5% of the sample. By far the most common pathological skeletal changes are lytic lesions leading to cavitation of cancellous bone, especially in the lower vertebral and sacro-iliac regions. It is argued that the changes seen and their distribution are most consistent with a diagnosis of tuberculosis. Applying clinical observations regarding bone involvement, it is estimated that a minimum of 26 skeletons were affected. This in turn indicates a very high population tuberculosis incidence. The Uxbridge sample is neither the only nor the earliest Iroquoian ossuary to display apparent tuberculosis (Hartney 1981). The common presence of this disease in some communities and its low incidence in others are discussed in the context of the epidemic wave phenomenon. There is strong evidence for warfare at Uxbridge, and this warfare may have produced crowding, poor hygiene and diet, such that the disease could flourish. 相似文献
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Christopher Boehm 《Human nature (Hawthorne, N.Y.)》1999,10(3):205-252
Proponents of the standard evolutionary biology paradigm explain human “altruism” in terms of either nepotism or strict reciprocity.
On that basis our underlying nature is reduced to a function of inclusive fitness: human nature has to be totally selfish
or nepotistic. Proposed here are three possible paths to giving costly aid to nonrelatives, paths that are controversial because
they involve assumed pleiotropic effects or group selection. One path is pleiotropic subsidies that help to extend nepotistic
helping behavior from close family to nonrelatives. Another is “warfare”—if and only if warfare recurred in the Paleolithic.
The third and most plausible hypothesis is based on the morally based egalitarian syndrome of prehistoric hunter-gatherers,
which reduced phenotypic variation at the within-group level, increased it at the between-group level, and drastically curtailed
the advantages of free riders. In an analysis consistent with the fundamental tenets of evolutionary biology, these three
paths are evaluated as explanations for the evolutionary development of a rather complicated human social nature.
This paper (in a series of drafts) has profited from comments by Michael Boehm, Donald T. Campbell, Bruce Knauft, Jane Lancaster,
Martin Muller, Peter J. Richerson, Gary Seaman, Craig Stanford, George Williams, Edward O. Wilson, David Sloan Wilson, and
two reviewers for Human Nature.
Christopher Boehm is a professor of anthropology and the director of the Jane Goodall Research Center, University of Southern
California. His research interests in political anthropology concern egalitarianism, feuding, warfare, and conflict resolution
(humans and chimpanzees). In biosocial anthropology he is interested in altruism, group selection, and decisions. 相似文献
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Aparecida Vilaca 《Ethnos》2013,78(1):83-106
The Wari’, a southern Amazonian group of the Txapakura linguistic family, ate their dead and their enemies until at least the beginning of the 1960s. This article argues the continuity between these two forms of cannibalism by demonstrating that the Wari’ conceive the ingestion of the dead as a means of transforming them into prey. Predation – a defining characteristic of Amerindian warfare cannibalism – comprises a crucial means of differentiating two terms set in relationship, whether these terms be allies and enemies, the Wari’ and animals, or the living and the dead. In a world peopled by actual or potential human subjects, to transform the other into prey is to guarantee oneself the exclusive position of human, despite this being an essentially temporary position. 相似文献
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A life table methodology was used for paleodemographic analysis of skeletons from the Larson site (39WW2), an Arikara village and cemetery dated to circa A.D. 1750–1785. Vital statistics on mortality, survivorship, age-specific probability of death, life expectancy and crude mortality rate were derived from skeletal data. The population had an extremely high infant mortality rate and high rates of childhood mortality. The lowest probability of death was for adolescents. Mortality increased for young adults, ages 15–19. This increase was especially marked for females, the actual peak of adult female mortality was during ages 15–19. A second mode in the female mortality curve occurred at ages 35–39. The greatest percentage of male deaths was observed in the fourth decade, ages 30–34. Only 4.0% of the population attained the age of 50. The population crude death rate was 76 per thousand per year. This estimate, although high, is congruent with archaeological and historical sources which report a rapid Arikara population decline during the Post-Contact period. Causes of specific deaths appear to be linked to childbirth (affecting mother and infant), starvation, diseases especially tuberculosis, and intertribal warfare. 相似文献
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