11β-hydroxysteroid dehydrogenase type 1 has no effect on survival during experimental malaria but affects parasitemia in a parasite strain-specific manner

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Effect of transforming growth factor-β2 on biological regulation of multilayer primary chondrocyte culture

YesCytokines are extremely potent biomolecules that regulate cellular functions and play multiple roles in initiation and inhibition of disease. These highly specialised macromolecules are actively involved in control of cellular proliferation, apoptosis, cell migration and adhesion. This work, investigates the effect of transforming growth factor-beta2 (TGF-β2) on the biological regulation of chondrocyte and the repair of a created model wound on a multilayer culture system. Also the effect of this cytokine on cell length, proliferation, and cell adhesion has been investigated. Chondrocytes isolated from knee joint of rats and cultured at 4 layers. Each layer consisted of 2 × 105 cells/ml with and without TGF-β2. The expression of mRNA and protein levels of TGF-β receptors and Smad1, 3, 4, and 7 have been analysed by RT-PCR and western blot analysis. The effect of different supplementations in chondrocyte cell proliferation, cell length, adhesion, and wound repair was statistically analysed by One-way ANOVA test. Our results showed that the TGFβ2 regulates mRNA levels of its own receptors, and of Smad3 and Smad7. Also the TGF-β2 caused an increase in chondrocyte cell length, but decreased its proliferation rate and the wound healing process. TGF-β2 also decreased cell adhesion ability to the surface of the culture flask. Since, TGF-β2 increased the cell size, but showed negative effect on cell proliferation and adhesion of CHC, the effect of manipulated TGF-β2 with other growth factors and/or proteins needs to be investigated to finalize the utilization of this growth factor and design of scaffolding in treatment of different types of arthritis

Chickpea

The narrow genetic base of cultivated chickpea warrants systematic collection, documentation and evaluation of chickpea germplasm and particularly wild Cicer species for effective and efficient use in chickpea breeding programmes. Limiting factors to crop production, possible solutions and ways to overcome them, importance of wild relatives and barriers to alien gene introgression and strategies to overcome them and traits for base broadening have been discussed. It has been clearly demonstrated that resistance to major biotic and abiotic stresses can be successfully introgressed from the primary gene pool comprising progenitor species. However, many desirable traits including high degree of resistance to multiple stresses that are present in the species belonging to secondary and tertiary gene pools can also be introgressed by using special techniques to overcome pre- and post-fertilization barriers. Besides resistance to various biotic and abiotic stresses, the yield QTLs have also been introgressed from wild Cicer species to cultivated varieties. Status and importance of molecular markers, genome mapping and genomic tools for chickpea improvement are elaborated. Because of major genes for various biotic and abiotic stresses, the transfer of agronomically important traits into elite cultivars has been made easy and practical through marker-assisted selection and marker-assisted backcross. The usefulness of molecular markers such as SSR and SNP for the construction of high-density genetic maps of chickpea and for the identification of genes/QTLs for stress resistance, quality and yield contributing traits has also been discussed

Carbon isotopic composition of isoprenoid tetraether in surface sediments of Lake Qinghai and surrounding soils

Isoprenoid GDGTs (iGDGTs), along with their constituent biphytanyl moieties, are biomarkers for archaea. In order to obtain more information on identifying the carbon source and potential carbon assimilation pathway of archaea in surface sediments of Lake Qinghai and the surrounding soils, the stable carbon isotopic composition of iGDGT-derived biphytanes as well as its relationship with delta C-13 values of total organic carbon (TOC) and dissolved inorganic carbon (DIC) was investigated. The delta C-13 values of iGDGT-derived biphytanes ranged from -42.7% to -20.3%. For example, the values for acyclic biphytanes (BP-0), the most abundant, varied from -25.0% to -22.1% in offshore sediments, -30.5% to -25.4% in surrounding soils and -42.7% to -32.0% in nearshore sediments. The wider variation than that of delta C-13(TOC) (-26.9% to -25.1%) in offshore sediments and that in surrounding soils indicated that delta C-13 values of BP-0 may be a sensitive indicator for examining the depositional environments between terrestrial and lacustrine systems. With average delta C-13 values of -23.6%, crenarchaeol-derived biphytanes (BP-cren) in offshore sediments were enriched in C-13 (ca. 3.6%) relative to TOC. In addition, the carbon isotopic fractionation between BP-cren and DIC was -21.3%, consistent with that reported for marine Thaumarchaeota. The enrichment in C-13 relative to TOC and the similar carbon isotopic fractionation indicated that Thaumarchaeota in offshore sediments of Qinghai Lake are autotrophic. With average delta C-13 values of -29.2%, BP-cren in surrounding soils was depleted by 0.9% to 12.8% in C-13 relative to DIC. The quite large scatter in carbon isotopic fractionation between BP-cren and DIC indicated that the biomass of soil Thaumarchaeota originated from inorganic and organic carbon sources, suggesting a mixotrophic lifestyle.</p

n-Alkan-2-one distributions in a northeastern China peat core spanning the last 16 kyr

Most research on long chain methyl ketones has focused on their origins and distributions. Their application in paleoclimate studies is less common than that of other n-alkyl lipids. The goal of this research was to explore this potential by studying n-alkan-2-ones from the Hani peat sequence in northeastern China. They were identified using gas chromatography-mass spectrometry (GC-MS) and showed a distribution ranging from C(19) to C(31) with a strong odd/even predominance. This type of distribution is considered to derive from Sphagum and microbial oxidation of n-alkanes. Comparison with climate sensitive indicators and macrofossil analysis shows that microbial oxidation of n-alkanes derived from higher plants was enhanced during the warm early Holocene period. This led us to develop three n-alkan-2-one proxies - C(27)/Sigma C(23-31) (C(27)/HMW-KET), carbon preference index (CPI(H)-KET) and average chain length (ACL((27-31))-KET) - as possible indicators of paleoclimate in the peat-forming environment. These proxies, in combination with C(27) n-alkane delta D values and peat cellulose delta(18)O records, might allow examination of paleo-ecosystem behavior during climatic evolution in northeastern China over the past 16,000 yr.</p

Branched and isoprenoid tetraether (BIT) index traces water content along two marsh-soil transects surrounding Lake Qinghai: Implications for paleo-humidity variation

The BIT index represents the relative abundances of branched glycerol dialkyl glycerol tetraethers (bGDGTs) and the isoprenoid GDGT, crenarchaeol. While bGDGTs are produced mainly by soil (anaerobic) bacteria, crenarchaeol is known to be a biomarker for aerobic ammonia oxidation by chemolithoauto-trophic Thaumarchaeota, particularly in the open ocean or lakes. Thus, the index in marine and lacustrine settings has been widely used as a proxy for soil input. Here, we have investigated GDGT distribution along two transects extending from the lake shore marsh to upland soils on the NE Qinghai-Tibetan plateau. The results show that soil water content (SWC) correlates positively with concentration of bGDGTs and negatively with concentration of crenarchaeol; consequently, there is a significant positive correlation between SWC and the BIT index. Our study highlights a new potential application of BIT as a humidity proxy in loess/soil and peat deposits.</p

Distribution of glycerol dialkyl glycerol tetraether lipids along an altitudinal transect on Mt. Xiangpi, NE Qinghai-Tibetan Plateau, China

The distribution of glycerol dialkyl glycerol tetraethers (GDGTs) can reflect continental environmental changes. Recently, the distribution of branched GDGTs (bGDGTs) has been proposed as a novel tool for paleoelevation reconstructions. Here we report the variation in TEX86 (tetraether index of 86 carbon atoms) of isoprenoidal GDGTs (iGDGTs) and MBT (methylation of branched tetraether index) of bGDGTs along an altitudinal transect on Mt. Xiangpi, NE Qinghai-Tibetan Plateau. Both TEX86 and MBT values of surface soils showed significant linear decreases with altitude (TEX86: R-2 = 0.65; n = 50; MBT: R-2 = 0.69; n = 24). We suggest that the apparent relationships between the two indices and altitude may be related to temperature. Our preliminary investigation suggests that the TEX86 index can potentially be applied as a paleoelevation indicator in addition to the MBT index on the Qinghai-Tibetan Plateau.</p

Distribution of glycerol dialkyl glycerol tetraethers in surface sediments of Lake Qinghai and surrounding soil

Glycerol dialkyl glycerol tetraethers (GDGTs) are increasingly used as proxies for paleoclimate studies of marine and lacustrine environments. While GDGT-based proxies have been applied to a number of lake environments globally, little is known about the distribution of GDGTs on the Qinghai-Tibet Plateau. We have investigated the isoprenoid GDGTs (iGDGTs) and branched GDGTs (bGDGTs) in Lake Qinghai sediments and the surrounding surface soil in order to examine their potential use as paleoclimate proxies on the Qinghai-Tibet Plateau. The results show that (i) the values of the iGDGT/bGDGT ratio for surrounding soil were at the higher end among globally distributed soils and consequently BIT values (avg. 0.71) at the lower end, (ii) the TEX86 values decreased while the MBT and CBT values increased along an onshore soil-nearshore sediment-offshore sediment transect, (iii) the TEX86 values for the offshore sediments were almost identical and their inferred temperatures were close to mean summer surface water temperature and (iv) the bGDGT-inferred mean annual air temperature (MAAT) and pH for soil were consistent with measured MAAT and pH. However, the CBT-inferred pH for offshore sediments seemed inconsistent with the pH of lake water or sediment. Our results suggest that (i) the higher pH may be an important factor leading to the higher iGDGT/bGDGT values (and lower BIT values) in surrounding surface soil, (ii) both iGDGTs and bGDGTs may originate from terrestrial input and in situ production for this saline lake, especially for nearshore sediments. However, for offshore sediments, terrestrial iGDGT input seems minor, and TEX86 may be useful for paleoclimate studies of Lake Qinghai.</p

Assessing the ratio of archaeol to caldarchaeol as a salinity proxy in highland lakes on the northeastern Qinghai-Tibetan Plateau

The ratio of archaeol to caldarchaeol (the ACE index) has been proposed recently as an index for paleosalinity reconstruction and is based principally on archaeal core lipids (CLs) from coastal salt pans (Turich, C., Freeman, K.H., 2011. Archaeal lipids record paleosalinity in hypersaline systems. Organic Geochemistry 42, 1147-1157). We have examined possible relationships between salinity and ACE in both CLs and intact polar lipids (IPLs) from suspended particulate matter (SPM) and surface sediments of lakes and surrounding soils on the northeastern Qinghai-Tibetan Plateau. Our results showed that ACE values were positively correlated with salinity in all samples; however, CL ACE values were systematically higher than IPL ACE values, probably due to different degradation kinetics of intact polar (IP) archaeol and IP caldarchaeol. On the other hand, surface sediment ACE values from both CLs and IPLs were lower than SPM ACE values, probably due to enhanced production of caldarchaeol relative to archaeol in the sediment. Our results demonstrate that the ACE proxy reflects changes in salinity in diverse environments on the Qinghai-Tibetan Plateau, which is promising for paleosalinity reconstruction; however, caution should be used when applying the salinity proxy before we have a better understanding of degradation kinetics of archaeal IPLs and in situ production of caldarchaeol and archaeol in sediments.</p