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51.
To study effects of altitude, monthly sampling was undertaken from June 1993 to May 1996 in the upper Kodayar reservoir (1312 m ASL), the lower Kodayar (92 m ASL) and Azhakia Pandiapuram (plain) (Tamilnadu, India). Temperature decreased with elevation at a rate of 1 °C per 240 m; the thermal range also decreased with increasing altitude. The number of days and quantity of precipitation decreased from 161 days and 366 cm yr-1 in the upper Kodayar to 92 days and 127 cm yr-1 at the Azhakia Pandiapuram (APP). Transparency decreased from 1.5 m at the upper Kodayar to about 0.5 m at the APP. Dissolved oxygen increased with decreasing altitude but remained high (>7 mg l-1) in all the three systems. Throughout the investigation, the upper Kodayar reservoir (<6.8) and lower Kodayar lake (<7.0) remained acidic, while the APP was always alkaline. Trends for CO2 and alkalinity of the three Kodayar systems were parallel to those for pH. Though widely oscillating across calendar months, nitrate averaged c. 30 g l-1, while phosphate increased from 8 g l-1 in the upper Kodayar to 18 g l-1 at the APP. Wide oscillations in nitrate suggest that it may be limiting productivity more than phosphorus. Chlorophyll-a values were c. 1.9 g l-1 throughout the year in the upper Kodayar, and between 10 and 20 g l-1 in the other two ecosystems; values peaked during the dry season, from January to April. Chlorophyll-a concentrations correlated positively with productivity; every g increase in chlorophyll-a caused 0.15 gC m-3 d-1 more production. The pristine water of the fragile upper Kodayar had the lowest productivity, and poorest diversity and population density. The species richness was assessed using organisms larger than 75 m filtered by a plankton net. There were five species (Staurastrum spp., Staurodesmus spp., Botryococcus) of phytoplankton, and three species of cladocerans and five species of copepods; population density averaged to 159 l-1 for phytoplankton, 0.3 l-1 for zooplankton. The lower Kodayar proved to be the richest for species diversity; there were 14 species of phytoplankton and six species of cladocerans and six species of copepods. Population density averaged to 203 l-1 for phytoplankton and 0.44 l-1 for zooplankton. The APP displayed moderate species richness; there were seven species of phytoplankton and six species of cladocerans, eight species of copepods and three species of rotifer; but the population density was comparatively higher than the upper and lower Kodayar; it averaged 412 l-1 for phytoplankton and 5.9 l-1 for zooplankton. These values fell within the range of values reported for other tropical and temperate lakes. Staurastrum, Ceriodaphnia cornuta, Tropocyclops, Thermocyclops and Mesocyclops sp. were present in all the aquatic systems and tolerated wide range pH between 6.5 and 8.0. APP was the most productive (4.4 gC m-3 d-1). Productivity holds positive correlation with pH and temperature; for every 1 °C increase in temperature it increased by 0.39 gC m-3 d-1 in these aquatic systems. 相似文献
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Anjana Bhardwaj Nivetha Ganesan Kazunoshin Tachibana Kimal Rajapakshe Constance T. Albarracin Preethi H. Gunaratne Cristian Coarfa Isabelle Bedrosian 《PloS one》2015,10(5)
IntroductionAnnexin A1 (ANXA1) is an anti-inflammatory protein reported to play a role in cell proliferation and apoptosis, and to be deregulated in breast cancer. The exact role of annexin A1 in the biology of breast cancer remains unclear. We hypothesized that the annexin A1 plays an oncogenic role in basal subtype of breast cancer by modulating key growth pathway(s).MethodsBy mining the Cancer Genome Atlas (TCGA)-Breast Cancer dataset and manipulating annexin A1 levels in breast cancer cell lines, we studied the role of annexin A1 in breast cancer and underlying signaling pathways.ResultsOur in-silico analysis of TCGA-breast cancer dataset demonstrated that annexin A1 mRNA expression is higher in basal subtype compared to luminal and HER2 subtypes. Within the basal subtype, patients show significantly poorer overall survival associated with higher expression of annexin A1. In both TCGA patient samples and cell lines, annexin A1 levels were significantly higher in basal-like breast cancer than luminal and Her2/neu-positive breast cancer. Stable annexin A1 knockdown in TNBC cell lines suppressed the mTOR-S6 pathway likely through activation of AMPK but had no impact on the MAPK, c-Met, and EGFR pathways. In a cell migration assay, annexin A1-depleted TNBC cells showed delayed migration as compared to wild-type cells, which could be responsible for poor patient prognosis in basal like breast cancers that are known to express higher annexin A1.ConclusionsOur data suggest that annexin A1 is prognostic only in patients with basal like breast cancer. This appears to be in part due to the role of annexin A1 in activating mTOR-pS6 pathway. 相似文献
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In Vivo Assessment of Cold Tolerance through Chlorophyll-a Fluorescence in Transgenic Zoysiagrass Expressing Mutant Phytochrome A 总被引:1,自引:0,他引:1
Mayank Anand Gururani Jelli Venkatesh Markkandan Ganesan Reto J?rg Strasser Yunjeong Han Jeong-Il Kim Hyo-Yeon Lee Pill-Soon Song 《PloS one》2015,10(5)
Chlorophyll-a fluorescence analysis provides relevant information about the physiology of plants growing under abiotic stress. In this study, we evaluated the influence of cold stress on the photosynthetic machinery of transgenic turfgrass, Zoysia japonica, expressing oat phytochrome A (PhyA) or a hyperactive mutant phytochrome A (S599A) with post-translational phosphorylation blocked. Biochemical analysis of zoysiagrass subjected to cold stress revealed reduced levels of hydrogen peroxide, increased proline accumulation, and enhanced specific activities of antioxidant enzymes compared to those of control plants. Detailed analyses of the chlorophyll-a fluorescence data through the so-called OJIP test exhibited a marked difference in the physiological status among transgenic and control plants. Overall, these findings suggest an enhanced level of cold tolerance in S599A zoysiagrass cultivars as reflected in the biochemical and physiological analyses. Further, we propose that chlorophyll-a fluorescence analysis using OJIP test is an efficient tool in determining the physiological status of plants under cold stress conditions. 相似文献
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The aim of the work is to investigate the effect of marine bacterial culture supernatants on biofilm formation of Vibrio spp., a major menace in aquaculture industries. Vibrio spp. biofilm cause life-threatening infections in humans and animals. Forty-three marine bacterial culture supernatants were
screened against the hydrophobicity index, initial attachment and biofilm formation in Vibrio spp. Twelve culture supernatants showed antibiofilm activity. The bacterial culture supernatants S8-07 (Bacillus pumilus) and S6-01 (B. indicus) inhibited the initial attachment, biofilm formation and dispersed the mature biofilm at 5% v/v concentration without inhibiting
the growth. Analysis by light microscopy and confocal laser scanning microscopy showed that the architecture of the biofilm
was destroyed by bacterial supernatants when compared to the control. The bacterial supernatants also reduce the surface hydrophobicity
of Vibrio spp. which is one of the important requirements for biofilm formation. Further characterization of antibiofilm activity in
S8-07 culture supernatant confirmed that it is an enzymatic activity and the size is more than 10 kDa and in S6-01, it is
a heat-stable, non-protein compound. Furthermore, both the supernatants failed to show any biosurfactant activity. The culture
supernatants of S8-07 and S6-01 with promising antibiofilm property have potential for application in medicine and marine
aquaculture. 相似文献
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Amylase inhibitor producing actinobacteria were isolated and characterized from terrestrial environment and there is no much
report found from marine environment, hence in the present study, 17 strains isolated from the rhizosphere sediments of mangroves
were tested for their amylase inhibition ability. Seawater requirement test for the growth of actinobacteria found that the
strains SSR-3, SSR-12 and SSR-16 requires at least 50% and SSR-6 requires at least 25% seawater for their growth. The inhibition
activity of both prokaryotic and eukaryotic amylase was tested by using Bacillus subtilis and Aspergillus niger. The maximum amylase activity (40mm) produced by the A. niger was taken as positive control, when the test actinobacteria strains grown in the medium they inhibited amylase activity and
was evidenced by the reduction in inhibition zone (14–37 mm) similarly the amylase produced by the Bacillus subtilis was also recorded maximum (35 mm) amylase activity and was taken as positive control, and the test atinobacterial strains
reduced enzyme action(12–33 mm) it varied levals. This indicates that the actinobacteria strains were controlled amylase enzyme
activity in both the cases. The strain SSR-10 was highly effective and SSR-8 was less effective in inhibiting eukaryotic amylase
produced by A. niger. The strain SSR-2 was effective and SSR-6 showed very less effect in inhibiting the prokaryotic amylase produced by the B subtilis. 相似文献
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Thanemozhi G Natarajan Bhaskar V Kallakury Christine E Sheehan Margaret B Bartlett Natarajan Ganesan Anju Preet Jeffrey S Ross Kevin T FitzGerald 《Cancer cell international》2010,10(1):13