Preliminary estimates of the potential for carbon mitigation in European soils through no-till farming

In this paper we estimate the European potential for carbon mitigation of no-till farming using results from European tillage experiments. Our calculations suggest some potential in terms of (a) reduced agricultural fossil fuel emissions, and (b) increased soil carbon sequestration. We estimate that 100% conversion to no-till farming would be likely to sequester about 23 Tg C y^–1 in the European Union or about 43 Tg C y^–1 in the wider Europe (excluding the former Soviet Union). In addition, up to 3.2 Tg C y^–1 could be saved in agricultural fossil fuel emissions. Compared to estimates of the potential for carbon sequestration of other carbon mitigation options, no-till agriculture shows nearly twice the potential of scenarios whereby soils are amended with organic materials. Our calculations suggest that 100% conversion to no-till agriculture in Europe could mitigate all fossil fuel-carbon emissions from agriculture in Europe. However, this is equivalent to only about 4.1% of total anthropogenic CO₂-carbon produced annually in Europe (excluding the former Soviet Union) which in turn is equivalent to about 0.8% of global annual anthropogenic CO₂-carbon emissions.     

Effects of fine‐scale genetic structure on male mating success in gynodioecious Beta vulgaris ssp. maritima

Plant mating systems are known to influence population genetic structure because pollen and seed dispersal are often spatially restricted. However, the reciprocal outcomes of population structure on the dynamics of polymorphic mating systems have received little attention. In gynodioecious sea beet (Beta vulgaris ssp. maritima), three sexual types co‐occur: females carrying a cytoplasmic male sterility (CMS) gene, hermaphrodites carrying a non‐CMS cytoplasm and restored hermaphrodites that carry CMS genes and nuclear restorer alleles. This study investigated the effects of fine‐scale genetic structure on male reproductive success of the two hermaphroditic forms. Our study population was strongly structured and characterized by contrasting local sex‐ratios. Pollen flow was constrained over short distances and depended on local plant density. Interestingly, restored hermaphrodites sired significantly more seedlings than non‐CMS hermaphrodites, despite the previous observation that the former produce pollen of lower quality than the latter. This result was explained by the higher frequency of females in the local vicinity of restored (CMS) hermaphrodites as compared to non‐CMS hermaphrodites. Population structure thus strongly influences individual fitness and may locally counteract the expected effects of selection, suggesting that understanding fine scale population processes is central to predicting the evolution of gender polymorphism in angiosperms.     

Molecular cloning and expression profiles of calreticulin gene from the diamondback moth,Plutella xylostella

Calreticulin (CRT) plays pivotal roles in Ca²⁺ homeostasis, molecular chaperoning, infection, inflammation and innate immunity. In an attempt to study the involvement of CRT in innate immunity, the full-length cDNA of calreticulin (PxCRT) was cloned from the diamondback moth, Plutella xylostella. It consists of 1674 bp (excluding poly-A tail) with a longest open reading frame (ORF) of 1197 bp encoding 398 amino acids. In silico analysis of PxCRT ORF reveals that it has various repeat motifs and endoplasmic reticulum retention signal found in all the calreticulin proteins. As expected, high amino acid sequence identities were found from other CRTs identified from Bombyx mori (87%), Galleria mellonella (87%), Apis mellifera (74%), Anopheles gambiae (74%), Tribolium castaneum (73%), Culex quinquefasciatus (73%), Rhodnius prolixus (72%), Nasonia vitripennis (71%), Drosophila melanogaster (71%) and Haemaphysalis qinghaiensis (68%). During development, P. xylostella expressed PxCRT predominantly in the pupal stage. In addition, spatial expression pattern analysis indicates that PxCRT was highly expressed in the silk gland. PxCRT mRNA, furthermore, was strongly induced 3 to 6 h after laminarin treatment, suggesting that PxCRT appears to be involved in immune responses and also plays an important role in the silk gland.     

Evaluation of biogenic and anthropogenic inputs of aliphatic hydrocarbons to Lake Taihu sediments using biomarkers

Surficial sediments from 13 sites throughout Lake Taihu, one of the largest urbanized freshwater lake systems in China, were analyzed for biomarkers (e.g., n-alkanes and hopanes) to track the origin of organic inputs (biogenic or anthropogenic), and, thus, to identify any ‘hot spots’ of hydrocarbon contamination. A distinct spatial distribution of aliphatic hydrocarbons in sediments was observed in Lake Taihu. At the northern tip of the lake (i.e., Meiliang and Wuli Bays), the highest mean aliphatic hydrocarbon concentration, with a significant contribution of an unresolved complex mixture (UCM), was found, indicating possible anthropogenic petroleum contamination (mainly from untreated and partially treated industrial and domestic sewage from Wuxi, Changzhou and other cities). This was supported by the n-alkane indices (e.g., small Carbon Preference Index and odd-to-even values) and a high degree of maturity of the hopane biomarkers. However, hydrocarbons from East Taihu were mainly biogenic, with the lowest mean concentrations, negligible or no contribution of UCM, abundance of vascular plant C₂₃–C₃₃ n-alkanes with a high odd-to-even predominance, and the presence of biogenic hopanes (e.g., 17β(H), 21β(H)-hopanes and hopenes). In the other areas of the lake, however, the predominance of biogenic in combination with petrogenic hydrocarbons was indicated by the biomarkers.     

The antiviral drug ribavirin is a selective inhibitor of S-adenosyl-L-homocysteine hydrolase from Trypanosoma cruzi

Ribavirin (1,2,4-triazole-3-carboxamide riboside) is a well-known antiviral drug. Ribavirin has also been reported to inhibit human S-adenosyl-L-homocysteine hydrolase (Hs-SAHH), which catalyzes the conversion of S-adenosyl-L-homocysteine to adenosine and homocysteine. We now report that ribavirin, which is structurally similar to adenosine, produces time-dependent inactivation of Hs-SAHH and Trypanosoma cruzi SAHH (Tc-SAHH). Ribavirin binds to the adenosine-binding site of the two SAHHs and reduces the NAD(+) cofactor to NADH. The reversible binding step of ribavirin to Hs-SAHH and Tc-SAHH has similar K(I) values (266 and 194 microM), but the slow inactivation step is 5-fold faster with Tc-SAHH. Ribavirin may provide a structural lead for design of more selective inhibitors of Tc-SAHH as potential anti-parasitic drugs.     

Physical and functional interaction between the α- and γ-secretases: A new model of regulated intramembrane proteolysis

Many single-transmembrane proteins are sequentially cleaved by ectodomain-shedding α-secretases and the γ-secretase complex, a process called regulated intramembrane proteolysis (RIP). These cleavages are thought to be spatially and temporally separate. In contrast, we provide evidence for a hitherto unrecognized multiprotease complex containing both α- and γ-secretase. ADAM10 (A10), the principal neuronal α-secretase, interacted and cofractionated with γ-secretase endogenously in cells and mouse brain. A10 immunoprecipitation yielded γ-secretase proteolytic activity and vice versa. In agreement, superresolution microscopy showed that portions of A10 and γ-secretase colocalize. Moreover, multiple γ-secretase inhibitors significantly increased α-secretase processing (r = −0.86) and decreased β-secretase processing of β-amyloid precursor protein. Select members of the tetraspanin web were important both in the association between A10 and γ-secretase and the γ→α feedback mechanism. Portions of endogenous BACE1 coimmunoprecipitated with γ-secretase but not A10, suggesting that β- and α-secretases can form distinct complexes with γ-secretase. Thus, cells possess large multiprotease complexes capable of sequentially and efficiently processing transmembrane substrates through a spatially coordinated RIP mechanism.     

Hedgehog signaling in skin cancers

An increasing progress on the role of Hedgehog (Hh) signaling for carcinogenesis has been achieved since the link of Hh pathway to human cancer was firstly established. In particular, the critical role of Hh signaling in the development of Basal cell carcinoma (BCC) has been convincingly demonstrated by genetic mutation analyses, mouse models of BCCs, and successful clinical trials of BCCs using Hh signaling inhibitors. In addition, the Hh pathway activity is also reported to be involved in the pathogenesis of Squamous Cell Carcinoma (SCC), melanoma and Merkel Cell Carcinoma. These findings have significant new paradigm on Hh signaling transduction, its mechanisms in skin cancer and even therapeutic approaches for BCC. In this review, we will summarize the major advances in the understanding of Hh signaling transduction, the roles of Hh signaling in skin cancer development, and the current implications of “mechanism-based” therapeutic strategies.     

Serum 27-nor-5β-cholestane-3,7,12,24,25 pentol glucuronide discovered by metabolomics as potential diagnostic biomarker for epithelium ovarian cancer

The aim of this study was to use a two steps strategy metabolomics to screen/identify and validate novel metabolic biomarker(s) for epithelial ovarian cancer (EOC). In the screening step, serum samples from 27 healthy women, 28 benign ovarian tumors, and 29 EOCs were analyzed by using LC-MS based nontargeted metabolomics. The three groups were separated with OSC filtered PLS-DA model, and six metabolites (27-nor-5β-cholestane-3,7,12,24,25 pentol glucuronide (CPG), phenylalanine, glycocholic acid, propionylcarnitine, Phe-Phe and Lyso PC (18:2)) were considered as potential biomarker candidates. In the validation step, the six metabolites were analyzed in targeted metabolomics by LC-selective ion monitoring mass spectrometry in another 685 serum samples with various clinical backgrounds. As a result, CPG was evaluated to be a potential biomarker and its content was elevated in EOC tissues compared with benign ovarian tumor tissues (p = 0.0005). Besides, CPG levels were found to be up-regulated in early stage EOC and in the three types of EOC histological types. Other variables such as nonovarian diseases, medicine consumption, gynecological inflammations, and menopausal state did not interfere in using CPG as diagnosis marker. CPG was found to be complementary to CA125. Our findings suggest that CPG can be considered a statistical relevant biomarker of EOC, ready for early stage detection.