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61.
62.
Sylvi Haldorsen Hasan Akan Bahattin ?elik Manfred Heun 《Vegetation History and Archaeobotany》2011,20(4):305-318
The domestication of the Neolithic founder crops of the Near East has recently been a topic of debate particularly with respect
to how rapidly the domestication of these crops occurred. One school of thought maintains that these processes lasted several
thousand years (‘protracted model’ with ‘gathering’, ‘cultivation’ and ‘domestication’ as three stages of a continuum, each
taking up to several thousand years), while another favors the view that domestication occurred much more quickly, over several
hundred years at most (‘rapid transition’). Our study focuses on one of these crops, 1-grained domesticated Einkorn wheat,
incorporating data from geology, vegetation history, and climate. In the Karacadağ region of southeastern Turkey, where 1-grained
Einkorn wheat was domesticated, the climate was severe (i.e. cold and dry) during the Younger Dryas. The climate of the Younger
Dryas acted as boundary during which a) conditions were not suitable for ‘cultivation’, and b) Einkorn would have retreated
to refugia exhibiting more suitable moisture-bearing soils that would have made ‘gathering’ difficult. Around 11600 cal. b.p., the Younger Dryas ended and a very rapid climatic amelioration commenced at the beginning of the Early Holocene, enabling
grasses to spread throughout the region. A ritual PPNA/PPNB site (G?bekli Tepe) and associated PPNB settlements such as Nevali
?ori and ?ay?nü were established at this time. In the settlements of Nevali ?ori and Cafer H?yük, the oldest domesticated
Einkorn was found in the earliest archaeological layers. This confirms that the inhabitants made use of domesticated 1-grained
Einkorn from the very beginning of settlement activity, although they continued to practice a mixed lifestyle as hunter-gatherers
and farmers. For ?ay?nü the issue is more complex, but here domesticated Einkorn also appears around the same time. In summary,
by 10400 cal. b.p. domesticated 1-grained Einkorn was present in large quantities at a variety of sites. This would give a maximum window of
time lasting approximately 1,200 years and is therefore not in agreement with the ‘protracted’ model but would be consistent
with a ‘rapid transition’. It is improbable that the ‘cultivation’ of wild Einkorn was practiced in the Karacadağ region,
since wild Einkorn was plentiful during the favorable growing conditions following the Younger Dryas, making it more likely
that ‘gathering’ would have been practiced. Because Einkorn has not been found in early settlements in the southern Levant,
this crop cannot have been ‘gathered’ and ‘cultivated’ there but instead was ‘domesticated’ independently and solely in southeastern
Turkey. Therefore, the YD acts as a boundary, providing a maximum time frame for 1-grained Einkorn domestication. 相似文献
63.
In the present study, we report the effect of vitamin A (Vit A, retinol palpitate) on kidney lipid peroxidation and 3-nitrotyrosine
(3-NT) levels induced after Escherichia coli administration to guinea pigs. Vit A was administrated intraperitoneally (i.p.) to guinea pigs at a dose 15,000 IU/kg per
day for 7 days prior to E. coli injection. On day 8, the animals were injected i.p. with E. coli dosed at 12 ×109 colony forming units per kilogram. Kidneys were collected 6 h after administration of E. coli. Malondialdehyde (MDA) as a lipid peroxidation product, and 3-NT levels were measured by reverse phase high-performance liquid
chromatography. There was a significant increase in MDA and 3-NT levels in lipopolysaccaharide-induced group (p<0.001). 3-NT was not detectable in kidney of normal control animals. However, Vit A administration prior to E. coli injection prevented 3-NT formation but did not prevent the rice in MDA level of kidney (p<0.001). Vit A alone did not alter the MDA level in the kidney of the control group. (Mol Cell Biochem 278: 33–37, 2005) 相似文献
64.
In the present study, antibacterial, antifungal, and antiviral properties of 15 lipohylic extracts obtained from different parts (leaf, branch, stem, kernel, shell skins, seeds) of Pistacia vera were screened against both standard and the isolated strains of Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecalis, Staphylococcus aureus, Candida albicans and C. parapsilosis by microdilution method. Both Herpes simplex (DNA) and Parainfluenza viruses (RNA) were used for the determination of antiviral activity of the P. vera extracts by using Vero cell line. Ampicilline, ofloxocine, ketoconazole, fluconazole, acyclovir and oseltamivir were used as the control agents. The extracts showed little antibacterial activity between the range of 128-256 microg/ml concentrations whereas they had noticeable antifungal activity at the same concentrations. Kernel and seed extracts showed significant antiviral activity compared to the rest of the extracts as well as the controls. 相似文献
65.
The flow of information through the epidermal growth factor receptor (EGFR) is shaped by molecular interactions in the plasma membrane. The EGFR is associated with lipid rafts, but their role in modulating receptor mobility and subsequent interactions is unclear. To investigate the role of nanoscale rafts in EGFR dynamics, we used single-molecule fluorescence imaging to track individual receptors and their dimerization partner, human epidermal growth factor receptor 2 (HER2), in the membrane of human mammary epithelial cells. We found that the motion of both receptors was interrupted by dwellings within nanodomains. EGFR was significantly less mobile than HER2. This difference was likely due to F-actin because its depolymerization led to similar diffusion patterns between the EGFR and HER2. Manipulations of membrane cholesterol content dramatically altered the diffusion pattern of both receptors. Cholesterol depletion led to almost complete confinement of the receptors, whereas cholesterol enrichment extended the boundaries of the restricted areas. Interestingly, F-actin depolymerization partially restored receptor mobility in cholesterol-depleted membranes. Our observations suggest that membrane cholesterol provides a dynamic environment that facilitates the free motion of EGFR and HER2, possibly by modulating the dynamic state of F-actin. The association of the receptors with lipid rafts could therefore promote their rapid interactions only upon ligand stimulation. 相似文献
66.
Glutathione S-Transferase M1, T1, P1 Genotypes and Risk for Development of Colorectal Cancer 总被引:3,自引:0,他引:3
Ateş NA Tamer L Ateş C Ercan B Elipek T Ocal K Camdeviren H 《Biochemical genetics》2005,43(3-4):149-163
The glutathione S-transferase (GST) supergene family is an important part of cellular enzyme defense against endogenous and exogenous chemicals, many of which have carcinogenic potential. The present investigation was conducted to detect a possible association between polymorphisms at the GSTM1, GSTT1, and GSTP1 genes and the interaction with cigarette smoking and colorectal cancer incidence. We examined 181 patients with colorectal cancer and 204 controls. DNA was extracted from whole blood, and the GSTM1, GSTT1, and GSTP1 polymorphisms were determined using a real-time polymerase chain reaction and fluorescence resonance energy transfer with a Light-Cycler instrument. Associations between specific genotypes and the development of colorectal cancer were examined by use of logistic regression analysis to calculate odds ratios (OR) and 95% confidence intervals (CI). The GSTM1 polymorphism was associated with an increased risk of developing colorectal cancer (OR = 1.62, 95% CI: 1.06–2.46). Also the risk of colorectal cancer associated with the GSTT1 null genotype was 1.64 (95% CI: 1.10–2.59). Statistically no differences were found between patients with colorectal cancer and control groups for the GSTP1 Ile/Ile, Ile/Val and Val/Val genotypes. In addition, the frequencies of the GSTM1 and GSTT1 deletion genotypes differed significantly between the cases and controls for current smokers; the GSTT1 null genotype especially is associated with a greater risk of colorectal cancer (OR = 2.44, 95% CI: 1.24–4.81). The GSTM1 and GSTT1 deletions were associated with an increased risk of developing a transverse or rectal tumor (OR = 1.86, 95% CI: 1.15–3.00; OR = 1.70, 95% CI: 1.02–2.84; respectively). The glutathione S-transferase polymorphisms were not associated with risk in patients stratified by age. The risk of colorectal cancer increased as putative high-risk genotypes increased for the combined genotypes of GSTM1 null, GSTT1 null, and either GSTP1 valine heterozygosity or GSTP1 valine homozygosity (OR = 2.69, 95% CI: 1.02–7.11). In conclusion, the results obtained in this study clearly suggest that those susceptibility factors related to different GST polymorphic enzymes are predisposing for colorectal cancer. 相似文献
67.
The aim of present study was to investigate the effects of 3,3′,5-triiodothyronine (T3) on rat testis both morphometrically and immunohistochemically with determining of insulin-like growth factor I (IGF-I) expression. Adult male Wistar-albino rats used in the study were divided into two groups; control and T3-treated groups. After T3 treatment there was observed to be a decrease in testicular weights, diameters of seminiferous tubules and the number of sertoli cells, and an increase in the number of leydig cells (P<0.05). Some of the seminiferous tubule lumens of T3 administrated rats had cellular debris. IGF-I was localized in sertoli cells, late spermatids and leydig cells of all groups. IGF-I immunoreactivity in T3 treated rats was higher than in controls in all stages of the cycle of rat seminiferous epithelium, but the staining intensity of leydig cells were similar in both groups. In conclusion, the present results suggest that T3 may modulate the testicular function by affecting IGF-I activity at the gonadal level. 相似文献
68.
ANDERS GONÇALVES
Da SILVA JESSICA R. EBERHARD TIMOTHY F. WRIGHT MICHAEL L. AVERY MICHAEL A. RUSSELLO 《Molecular ecology》2010,19(16):3336-3350
The monk parakeet (Myiopsitta monachus) is a successful invasive species that does not exhibit life history traits typically associated with colonizing species (e.g., high reproductive rate or long‐distance dispersal capacity). To investigate this apparent paradox, we examined individual and population genetic patterns of microsatellite loci at one native and two invasive sites. More specifically, we aimed at evaluating the role of propagule pressure, sexual monogamy and long‐distance dispersal in monk parakeet invasion success. Our results indicate little loss of genetic variation at invasive sites relative to the native site. We also found strong evidence for sexual monogamy from patterns of relatedness within sites, and no definite cases of extra‐pair paternity in either the native site sample or the examined invasive site. Taken together, these patterns directly and indirectly suggest that high propagule pressure has contributed to monk parakeet invasion success. In addition, we found evidence for frequent long‐distance dispersal at an invasive site (~100 km) that sharply contrasted with previous estimates of smaller dispersal distance made in the native range (~2 km), suggesting long‐range dispersal also contributes to the species’ spread within the United States. Overall, these results add to a growing body of literature pointing to the important role of propagule pressure in determining, and thus predicting, invasion success, especially for species whose life history traits are not typically associated with invasiveness. 相似文献
69.
The effects of Se phytotoxicity on the antioxidant systems of leaf tissues in barley (Hordeum vulgare L.) seedlings 总被引:1,自引:0,他引:1
A hydroponic experiment was carried out in a growth chamber to investigate the impact of Selenium (Se) levels on physiological and biochemical characteristics of a barley cultivar. Membrane lipid peroxidation (LPO), proline accumulation and antioxidant activities of some enzymes of barley seedlings under Se toxicity were investigated. Significant increase in thiobarbituric acid reactive substance (TBARS) content, and a stimulation of catalase (CAT, 1.11.1.6), ascorbate peroxidase (APX, 1.11.1.11), glutathione reductase (GR, 1.6.4.2), and glutathione S-transferase (GST, 2.5.1.18) activities were recorded in barley seedlings subjected to 2, 4, 8, 16 ppm Se. Superoxide dismutase (SOD, EC 1.15.1.1) activity was not altered significantly. Plant height and chlorophyll content of the seedlings were also affected significantly in a dose dependent manner by Se treatment. Considerable amount of proline accumulation was also observed in response to Se treatment. The results indicated that increases in the activities of the antioxidant enzymes were not sufficient to protect cell membrane against Se toxicity. 相似文献
70.
Mustafa Çelik Fatma Ünal Deniz Yüzbaşıoğlu Serkan Yılmaz Hüseyin Aksoy Şengül Karaman 《Cytotechnology》2006,51(2):99-104
In this investigation, clastogenic effects of Thymus kotschyanus var. glabrescens Boiss. extract (TE) and anticlastogenic effects of this extract against Mitomycin C (MMC) induced chromosome damage have been evaluated in human peripheral blood lymphocytes in vitro. Two series of experiments were conducted. In the first, only 10−5, 10−4, 10−3 and 10−2 μl ml−1 concentrations of TE were used for 48 h to detect potential clastogenicity. In the second, MMC (0.38 μg ml−1) plus 10−5, 10−4, 10−3 and 10−2 μl ml−1 concentrations of TE were used for 48 h to determine anticlastogenic effects. TE did not increase sister chromatid exchanges (SCEs) (except 10−2 μl ml concentration) and chromosome aberrations (CAs) significantly compared with negative and solvent controls. However, it decreased the frequency of MMC induced chromosome aberrations. Decreasing was significant at 10−4, 10−3 and 10−2 μl ml−1 concentrations. On the other hand, TE significantly increased MMC-induced SCEs for all treatment groups compared with positive control. 相似文献