The influence of stream invertebrate composition at neighbouring sites on local assemblage composition

1. The composition of freshwater invertebrate assemblages at a location is determined by a range of physico‐chemical and biotic factors in the local environment, as well as larger‐scale spatial factors such as sources of recruits. We assessed the relative importance of the species composition of local neighbourhoods and proximal environmental factors on the composition of invertebrate assemblages. 2. Macroinvertebrate assemblages were sampled at 188 running‐water sites in the catchment of the River Rede, north‐east England. A total of 176 species were recorded. 3. Environmental data, in the form of 13 biotic and abiotic measurements that described stream physical structure, aquatic vegetation and water characteristics, were recorded for each site. Detrended correspondence analysis was then used to simplify nine of these stream environmental variables to create an index of stream structure. 4. The species composition of the invertebrate assemblages was related to the environmental variables, using an information theoretic approach. The impact of the species composition of neighbouring sites on each site was determined using Moran's I and autoregressive modelling techniques. 5. Species composition was primarily associated with water pH and stream structure. The importance of the species composition of neighbouring sites in determining local species assemblages differed markedly between taxa. The autoregressive component was low for Coleoptera, intermediate for Trichoptera and Plecoptera, and high for Ephemeroptera. 6. We hypothesise that the observed differences in the autoregressive component amongst these orders reflects variation in their dispersal abilities from neighbouring sites.     

Deviations in skeletons of radiolarians

Deviations in the skeleton structure of radiolarians are extremely rare in the fossil record. They are known from the Devonian to Recent. This is a very ancient and periodically repeated phenomenon, which should be regarded as a regularity or “lost chance” rather than exotic or accident. Emergence of deviant “mutants” in radiolarians is probably connected with two main causes, i.e., disturbance during reproduction and mutations in particular modules. From the point of view of the morphogenesis of skeletal structures, deviancy facilitates the recognition of relatively “weak” modules–blocks in the general skeleton pattern, which are subject to structural changes. Nonheritable deviant variants have been revealed in skeletons of 61 radiolarian in all of three subphyla of the phylum Radiolaria: Polycystina, Phaeodaria, and Collodaria. Three deviant types are recognized: multiplicative, posterioric and supplemental.     

Sulforaphane Suppresses Hepatitis C Virus Replication by Up-Regulating Heme Oxygenase-1 Expression through PI3K/Nrf2 Pathway

Hepatitis C virus (HCV) infection-induced oxidative stress is a major risk factor for the development of HCV-associated liver disease. Sulforaphane (SFN) is an antioxidant phytocompound that acts against cellular oxidative stress and tumorigenesis. However, there is little known about its anti-viral activity. In this study, we demonstrated that SFN significantly suppressed HCV protein and RNA levels in HCV replicon cells and infectious system, with an IC₅₀ value of 5.7 ± 0.2 μM. Moreover, combination of SFN with anti-viral drugs displayed synergistic effects in the suppression of HCV replication. In addition, we found nuclear factor erythroid 2-related factor 2 (Nrf2)/HO-1 induction in response to SFN and determined the signaling pathways involved in this process, including inhibition of NS3 protease activity and induction of IFN response. In contrast, the anti-viral activities were attenuated by knockdown of HO-1 with specific inhibitor (SnPP) and shRNA, suggesting that anti-HCV activity of SFN is dependent on HO-1 expression. Otherwise, SFN stimulated the phosphorylation of phosphoinositide 3-kinase (PI3K) leading Nrf2-mediated HO-1 expression against HCV replication. Overall, our results indicated that HO-1 is essential in SFN-mediated anti-HCV activity and provide new insights in the molecular mechanism of SFN in HCV replication.     

Host-plant relationships of the casebearers (Lepidoptera, Coleophoridae): Communication III

An alphabetical list of about 700 species of casebearers with characteristics of their trophic specialization is given. The quantitative distribution of oligophagous species over 30 host-plant families is shown.     

Familial breast/ovarian cancer and BRCA1/2 genetic screening: the role of immunohistochemistry as an additional method in the selection of patients.

Only 20-25% of families screened for BRCA1/2 mutations are found positive. Because only a positive result is informative, we studied the role of BRCA1/2 immunohistochemistry as an additional method for patient selection. From 53 high-risk-affected probands, 18 (34%) had available paraffin blocks of their tumors and were selected for this study. Mutation screening was done by conformation-sensitive gel electrophoresis and multiplex ligation-dependent probe amplification. For immunohistochemistry, 21 neoplastic specimens (15 breast carcinomas, 5 ovary neoplasms, and 1 rectal adenocarcinoma) were analyzed with BRCA1 (monoclonal antibody, Ab-1, oncogene) and BRCA2 (polyclonal antibody, Ab-2, oncogene) antibodies. Absence of the BRCA1 protein was confirmed in negative tumors by Western blotting. Seven patients were positive for BRCA1/2 mutations: 5 for BRCA1 and 2 for BRCA2. Four out of five positive patients had tumors negative for BRCA1 immunostaining, and the remaining 13 BRCA1-negative patients had positive BRCA1 immunostaining in all tumor samples. Sensitivity to predict for BRCA1 mutation carriers was 80%, and specificity was 100%, with a positive predictive value of 100% and a negative predictive value of 93%. This correlation was statistically significant (p=0.001). No correlation was observed for BRCA2. If larger studies confirm these results, high-risk patients with BRCA1-negative tumors should be screened first for this gene.