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1.
The Acheulian Technocomplex exhibits two phenomena: variability and conservatism. Variability is expressed in the composition and frequencies of tool types, particularly in the varying frequencies of bifaces (handaxes and cleavers). Conservatism is expressed in the continuous presence of bifaces along an immense time trajectory. The site of Gesher Benot Ya‘aqov (GBY) offers a unique opportunity to study aspects of variability and conservatism as a result of its long cultural-stratigraphic sequence containing superimposed lithic assemblages. This study explores aspects of variability and conservatism within the Acheulian lithic assemblages of GBY, with emphasis placed on the bifacial tools. While variability has been studied through a comparison of typological frequencies in a series of assemblages from the site, evidence for conservatism was examined in the production modes expressed by the reduction sequence of the bifaces. We demonstrate that while pronounced typological variability is observed among the GBY assemblages, they were all manufactured by the same technology. The technology, size, and morphology of the bifaces throughout the entire stratigraphic sequence of GBY reflect the strong conservatism of their makers. We conclude that the biface frequency cannot be considered as a chrono/cultural marker that might otherwise allow us to distinguish between different phases within the Acheulian. The variability observed within the assemblages is explained as a result of different activities, tasks, and functions, which were carried out at specific localities along the shores of the paleo-Hula Lake in the early Middle Pleistocene.  相似文献   
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The relationships among the lactate threshold (LT), ventilatory threshold (VT), and intracellular biochemical events in exercising muscle have not been well defined. Therefore 14 normal subjects performed incremental plantar flexion to exhaustion on 2 study days, the first for determination of LT and VT and the second for continuous 31P nuclear magnetic resonance spectroscopy of calf muscle. Exercising calf muscle pH fell precipitously at 66.4 +/- 3.4% (SE) of the maximum O2 uptake (VO2max) and was termed the intramuscular pH threshold. This did not occur at a significantly different metabolic rate from that at the LT (78.6 +/- 5.9% VO2max) or at the VT (75.0 +/- 4.1% VO2max, P = 0.15 by analysis of variance). Four subjects showed an intramuscular pH threshold and VT without a perceptible rise in forearm venous blood lactate. It is concluded that traditional markers of the "anaerobic threshold," the LT and VT, occur as intramuscular pH becomes acid for a group of normal subjects undergoing incremental exercise to exhaustion. It is speculated that neuronal pathways linking intramuscular biochemical events to the ventilatory control center may explain the intact VT in those subjects without an "intermediary" LT.  相似文献   
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Infants admitted to the Neonatal Intensive Care Unit at Tampa General Hospital, Tampa, Florida, were cultured for group B streptococci (GBS). Culture swabs were quantified for GBS to determine the magnitude of colonization in infected infants. Thirty-seven (17%) of the 217 infants cultured were positive for GBS. Six of these colonized infants developed sepsis, with blood cultures positive for GBS. Septic infants generally were colonized by large numbers of GBS (105 bacteria/culture swab) at two or more external skin sites, in comparison to aseptic infants, who were lightly colonized with GBS. The data suggest a possible correlation between magnitude of colonization by GBS at external skin sites and development of GBS sepsis in newborn infants.  相似文献   
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Source and extent of Klebsiella pneumoniae in the paper industry.   总被引:6,自引:5,他引:1       下载免费PDF全文
Three pulp and paper mill processing plants were evaluated for fecal coliform and Klebsiella pneumoniae bacterial concentrations. Freshwater consumed by paper industries contained minimum detectable levels of K. pneumoniae, less than 10 organisms per 100 ml. Elevated concentrations of K. pneumoniae could be traced from early pulping stages to water processing reuse systems. Concentrations of K. pneumoniae (thermotolerant and thermointolerant) ranged from 40,000 organisms per 100 ml to an estimated 3 x 10(6) organisms per 100 ml. K. pneumoniae biotyping provided evidence for the selective growth and persistence of K. pneumoniae from the initial wood washing stages through to the final effluent discharge. Wastewater treatment had limited effects in reducing K. pneumoniae concentrations. K. pneumoniae levels ranged from 40 organisms per 100 ml to an estimated 10(6) organisms per 100 ml. The presence of K. pneumoniae in water indicates degraded water quality, and its significance with regard to human health effects has yet to be examined.  相似文献   
6.
Interscapular brown adipose tissue (BAT) weighed more in rats given access to a solution of sucrose in addition to a nutritionally complete basal diet than in rats eating only a basal diet. This incremental effect of drinking sucrose solution occurs across a variety of dietary conditions. In the first experiment, rats were fed diets containing either 9%, 18%, 27% or 36% casein. Rats given access to a sucrose solution had significantly larger brown fat pads than controls when the diets contained 9 or 18% casein, but not when diets contained either 27% or 36% casein. The second experiment examined the weight of brown adipose tissue as a function of the type of protein and the percentage of fat in the diet. Animals given a sucrose solution had significantly more BAT than animals not given sucrose. Neither the type of protein (casein or soy protein) nor the percentage of fat (14.5% or 36.4%) in the diet influenced the weight of BAT. Animals given access to either a sucrose solution or a glucose solution had significantly heavier BAT than animals given access to a fructose solution, granulated sucrose or water.  相似文献   
7.
A method for the quantitative determination of tissue ferritin protein is described. It is based on the electroimmunoassay of Laurell [Laurell, C. B. (1966) Anal. Biochem.15, 45–52] and uses the iron content of ferritin for its identification. It measures as little as 0.1 μg of ferritin protein, requires only a few milligrams of tissue, and is rapidly performed.  相似文献   
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This study focuses on Kaizer Hill, a quarry site located in the vicinity of the city of Modiin where remains of a single prehistoric cultural entity assigned to the Pre-Pottery Neolithic A were discovered. A systematic survey revealed that large-scale quarrying activities have left damage markings on the bedrock of the Hilltop and its slopes. We aim to present here our findings from the Hilltop, which are concerned with the human impact on rock surfaces and the lithic artifacts retrieved during the survey. It is evident that the Pre-Pottery Neolithic A inhabitants of the area changed their landscape forever, “stripping” the caliche surface and penetrating it in search of flint bedded in the bedrock.  相似文献   
10.
Klopstock N  Levy C  Olam D  Galun E  Goldenberg D 《FEBS letters》2007,581(21):3986-3990
To overcome positional and methylation effects on transgene expression, we developed a universal cloning cassette for in vivo assessment of regulatory elements using the luciferase reporter gene and the CCCD camera. Monitoring luciferase expression pattern in live mice enables screening of large numbers of transgenic founders quickly and inexpensively. We demonstrate that in the engineered transgenic mice, the chicken beta-globin 5'HS4 insulator did not always provide the desirable expression pattern, and the Island Element, responsible for the demethylation of the surrounding DNA region, was not beneficial. Both tested liver-specific and developmentally regulated promoters exhibited the expected expression pattern in most transgenic founders.  相似文献   
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