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1.
Here we present an analytical technique for the measurement and evaluation of changes in chronologically sequenced assemblages. To illustrate the method, we studied the cultural evolution of European cooking as revealed in seven cook books dispersed over the past 800 years. We investigated if changes in the set of commonly used ingredients were mainly gradual or subject to fashion fluctuations. Applying our method to the data from the cook books revealed that overall, there is a clear continuity in cooking over the ages – cooking is knowledge that is passed down through generations, not something (re-)invented by each generation on its own. Looking at three main categories of ingredients separately (spices, animal products and vegetables), however, disclosed that all ingredients do not change according to the same pattern. While choice of animal products was very conservative, changing completely sequentially, changes in the choices of spices, but also of vegetables, were more unbounded. We hypothesize that this may be due a combination of fashion fluctuations and changes in availability due to contact with the Americas during our study time period. The presented method is also usable on other assemblage type data, and can thus be of utility for analyzing sequential archaeological data from the same area or other similarly organized material. 相似文献
2.
Population-specific assessment and management of anadromous fish at sea requires detailed information about the distribution at sea over ontogeny for each population. However, despite a long history of mixed-stock sea fisheries on Atlantic salmon, Salmo salar, migration studies showing that some salmon populations feed in different regions of the Baltic Sea and variation in dynamics occurs among populations feeding in the Baltic Sea, such information is often lacking. Also, current assessment of Baltic salmon assumes equal distribution at sea and therefore equal responses to changes in off-shore sea fisheries. Here, we test for differences in distribution at sea among and within ten Atlantic salmon Salmo salar populations originating from ten river-specific hatcheries along the Swedish Baltic Sea coast, using individual data from >125,000 tagged salmon, recaptured over five decades. We show strong population and size-specific differences in distribution at sea, varying between year classes and between individuals within year classes. This suggests that Atlantic salmon in the Baltic Sea experience great variation in environmental conditions and exploitation rates over ontogeny depending on origin and that current assessment assumptions about equal exploitation rates in the offshore fisheries and a shared environment at sea are not valid. Thus, our results provide additional arguments and necessary information for implementing population-specific management of salmon, also when targeting life stages at sea. 相似文献
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myc Boxes, Which Are Conserved in myc Family Proteins, Are Signals for Protein Degradation via the Proteasome 总被引:9,自引:4,他引:5 下载免费PDF全文
Elizabeth M. Flinn C. Magnus C. Busch Anthony P. H. Wright 《Molecular and cellular biology》1998,18(10):5961-5969
Cellular levels of the rapidly degraded c-myc protein play an important role in determining the proliferation status of cells. Increased levels of c-myc are frequently associated with rapidly proliferating tumor cells. We show here that myc boxes I and II, found in the N termini of all members of the myc protein family, function to direct the degradation of the c-myc protein. Both myc boxes I and II contain sufficient information to independently direct the degradation of otherwise stably expressed proteins to which they are fused. At least part of the myc box-directed degradation occurs via the proteasome. The mechanism of myc box-directed degradation appears to be conserved between yeast and mammalian cells. Our results suggest that the myc boxes may play an important role in regulating the level and activity of the c-myc protein. 相似文献
6.
Barbara Wegiel Thomas Jiborn Magnus Abrahamson Leszek Helczynski Leo Otterbein Jenny Liao Persson Anders Bjartell 《PloS one》2009,4(11)
Cystatin C is believed to prevent tumor progression by inhibiting the activities of a family of lysosomal cysteine proteases. However, little is known about the precise mechanism of cystatin C function in prostate cancer. In the present study, we examined the expression of cystatin C and its association with matrix metalloproteinases 2 (MMP2) and androgen receptor (AR) in a tissue microarray comparing benign and malignant specimens from 448 patients who underwent radical prostatectomy for localized prostate cancer. Cystatin C expression was significantly lower in cancer specimens than in benign tissues (p<0.001) and there was a statistically significant inverse correlation between expression of cystatin C and MMP2 (rs
2 = −0.056, p = 0.05). There was a clear trend that patients with decreased level of cystatin C had lower overall survival. Targeted inhibition of cystatin C using specific siRNA resulted in an increased invasiveness of PC3 cells, whereas induction of cystatin C overexpression greatly reduced invasion rate of PC3 in vitro. The effect of cystatin C on modulating the PC3 cell invasion was provoked by Erk2 inhibitor that specifically inhibited MAPK/Erk2 activity. This suggests that cystatin C may mediate tumor cell invasion by modulating the activity of MAPK/Erk cascades. Consistent with our immunohistochemical findings that patients with low expression of cystatin C and high expression of androgen receptor (AR) tend to have worse overall survival than patients with high expression of cystatin C and high AR expression, induced overexpression of AR in PC3 cells expressing cystatin C siRNA greatly enhanced the invasiveness of PC3 cells. This suggests that there may be a crosstalk between cystatin C and AR-mediated pathways. Our study uncovers a novel role for cystatin C and its associated cellular pathways in prostate cancer invasion and metastasis. 相似文献
7.
1. Harvestmen are predators, although they suspected of being partly omnivorous by including fruits in their diet. 2. In the present study, the right-angled mixture triangle (RMT) was used to analyse the macronutritional niche of the harvestman Opilio canestrinii, an invasive species in northern Europe. The study design followed a double-test procedure in which the animals were subjected to two self-selection tests: the first one immediately after being caught in the field and the second after 1 week of ad libitum feeding during which the animals became satiated and nutritionally balanced. A comparison of results from the two tests indicates whether the animals were food limited in the field, and whether they were limited by a particular macronutrient. 3. Females were found to be food limited in the field, whereas males were not. Opilio canestrinii had a target intake of 28% lipid : 52% protein : 20% carbohydrate [i.e. with a considerable proportion of carbohydrate (sugar) in the diet]. Both sexes were non-protein limited in the field, with sugar being more limiting than lipid. 4. The results indicate considerable inclusion of plant-derived sugar in the natural diet. This conclusion was supported by a separate experiment showing enhanced performance (survival, gain in mass) in animals whose only energy supply was fresh fruit. 5. It is concluded that the harvestman is best characterized as an omnivorous predator. 相似文献
8.
Marie Lisandra Zepeda Mendoza Johannes Lundberg Magnus Ivarsson Paula Campos Johan A. A. Nylander Therese Sallstedt Love Dalen 《PloS one》2016,11(3)
Speleothems are secondary mineral deposits normally formed by water supersaturated with calcium carbonate percolating into underground caves, and are often associated with low-nutrient and mostly non-phototrophic conditions. Tjuv-Ante’s cave is a shallow-depth cave formed by the action of waves, with granite and dolerite as major components, and opal-A and calcite as part of the speleothems, making it a rare kind of cave. We generated two DNA shotgun sequencing metagenomic datasets from the interior of a speleothem from Tjuv-Ante’s cave representing areas of old and relatively recent speleothem formation. We used these datasets to perform i) an evaluation of the use of these speleothems as past biodiversity archives, ii) functional and taxonomic profiling of the speleothem’s different formation periods, and iii) taxonomic comparison of the metagenomic results to previous microscopic analyses from a nearby speleothem of the same cave. Our analyses confirm the abundance of Actinobacteria and fungi as previously reported by microscopic analyses on this cave, however we also discovered a larger biodiversity. Interestingly, we identified photosynthetic genes, as well as genes related to iron and sulphur metabolism, suggesting the presence of chemoautotrophs. Furthermore, we identified taxa and functions related to biomineralization. However, we could not confidently establish the use of this type of speleothems as biological paleoarchives due to the potential leaching from the outside of the cave and the DNA damage that we propose has been caused by the fungal chemical etching. 相似文献
9.
Differential regulation of Dk and Kk major histocompatibility complex class I proteins on the cell surface after infection of murine cells by pseudorabies virus. 下载免费PDF全文
After pseudorabies virus (PRV) infection of murine L929 cells, the cell surface expression of major histocompatibility complex (MHC) class I proteins changes such that the total amount of MHC class I molecules remains relatively constant but the levels of the individual alleles Dk and Kk vary. This is an active process involving at least three PRV gene products that act in an allele-specific manner such that cell surface expression of MHC class I Dk is decreased and that of Kk is increased. Our results indicate that an early gene product mediates the overall reduction in Dk protein and a late gene product which is mutant in the attenuated PRV strain Bartha mediates the increase in Kk protein. We provide additional evidence for a third gene product involved in the regulation of the synthesis of both the Dk and Kk proteins. In addition, we show that the early decrease in the Dk protein is not due to a block in synthesis or processing of the complex through the secretory system. 相似文献
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