20 km) a flexible, reactive approach, coupled with continual monitoring for mink presence is necessary. Survival of reintroduced water voles at four sub-sites within our mink removal sites suggest that the reactive mink removal strategy adopted in this study was sufficient for
water vole protection. We discuss the use of an adaptive management approach LY2157299 purchase in local mink management, and consider the wider implications of our results for invasive species control on mainlands. (C) 2008 Elsevier Ltd. All rights reserved.”
“The exosome is a conserved protein complex that is responsible for essential 3′ –> 5′ RNA degradation in both the nucleus and the cytosol. It is composed of a nine-subunit core complex to which co-factors confer both RNA substrate recognition and ribonucleolytic activities. Very few exosome co-factors have been identified in plants. Here, we have characterized a putative RNA helicase, AtMTR4, that is involved in the degradation of several nucleolar exosome substrates in Arabidopsis thaliana. We show that AtMTR4, rather than its closely related protein HEN2, is required for proper rRNA biogenesis in Arabidopsis. AtMTR4 is mostly localized HSP990 nmr in the nucleolus, a subcellular compartmentalization that is shared with another exosome co-factor, RRP6L2. AtMTR4 and RRP6L2 cooperate
in several steps of rRNA maturation and surveillance, such as processing the 5.8S rRNA and removal of rRNA maturation by-products. Interestingly, degradation of the Arabidopsis 5′ external transcribed spacer (5′ ETS) requires cooperation of both the 5′ –> 3′ and 3′ –> 5′ exoribonucleolytic pathways. Accumulating AtMTR4 targets give rise to illegitimate small RNAs; however, these do not affect rRNA metabolism or contribute to the phenotype of mtr4 mutants. Plants lacking AtMTR4 are viable but show several developmental defects, including aberrant vein patterning and pointed first leaves. The mtr4 phenotype resembles
that of several ribosomal protein and nucleolin mutants, and may be explained by delayed ribosome biogenesis, as we observed a reduced rate of rRNA accumulation selleck chemical in mtr4 mutants. Taken together, these data link AtMTR4 with rRNA biogenesis and development in Arabidopsis.”
“In the present study, glycidyl methacrylate (GMA) grafted medium density polyethylene (MDPE-g-GMA) was synthesized in the molten state and applied as a reactive compatibilizer in MDPE/polyamid6 (PA6) and in MDPE/poly(ethylene terephtalate) (PET) blends. Graft copolymerization of GMA onto MDPE was performed in presence and absence of styrene, with different concentrations of dicumyl peroxide (DCP) as a radical initiator. In the presence of styrene, the MDPE-g-GMA with 6% GMA was obtained by addition of only 0.1 phr of DCP. Furthermore, the maximum grafting was reached when 0.6 and 0.7 phr concentration of DCP for styrene containing and styrene free samples were used, respectively.