Search

The Carpentarian rock-rat (Zyzomys palatalis) is a critically endangered endemic rodent known from only four sandstone gorges in the southeast Gulf of Carpentaria, Northern Territory, Australia. These gorges harbour thickets of monsoon rainforest and broadleaf woodland, surrounded by a Eucalypt savanna matrix. The long-term persistence of Z. palatalis is threatened by altered fire regimes, grazing by feral animals and stock, weed intrusion, and the stochastic hazards associated with small, fragmented populations. To assess the relative importance of these threats and develop practical management options, a population and habitat simulation model was developed, based on the best existing data. Population viability was predicted to be highly sensitive to the frequency of hot, late dry-season fires. Progressive habitat degradation (due predominantly to intense late dry-season fires) is likely to substantially reduce population size and lead to the probable extinction of the species within the next 100 years. The most effective management strategy to counteract this threat would be regular, controlled, fuel reduction burns in the vegetation around the gorge entrances during the early dry season. Establishing a new population (through translocation of captive-bred individuals) would not appreciably reduce extinction risk, but could provide valuable additional data on the impact of threats, if conducted as an adaptive management experiment. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ultrafine RuNPs stabilised by a phosphine oxide-modified polymer immobilized ionic liquid. • Complete selectivity for the partial reduction of aromatic and heteroaromatic nitroarenes to the corresponding N -arylhydroxylamine. • Highest initial turn over frequency to be reported for a RuNP catalysed partial reduction of nitrobenzene to N -phenylhydroxylamine. • Reduction of electron rich amino nitroarenes to the aniline proposed to occur via a quinondiimine-derived iminium. • High activity and selectivity retained over five reuses with only a minor reduction in conversion. RuNPs stabilised by a polymer immobilised ionic liquid derived from co-polymerisation of a PEG-substituted imidazolium-based styrene monomer and diphenyl(4-vinylphenyl)phosphine oxide, RuNP@O = PPh 2 -PEGPIILS, (2) is a remarkably efficient and selective catalyst for the hydrazine hydrate-mediated partial reduction of nitroarenes to the corresponding N -arylhydoxylamine. Near quantitative conversion to N -phenylhydroxylamine with > 99 % selectivity was obtained after only 2 h when the reaction was conducted at 25 °C in ethanol under an inert atmosphere using 0.1 mol% catalyst. Under these conditions, the composition-time profile showed that the reduction occurred via the direct pathway whereas reactions in air gave a mixture of azoxy-based products due to competing condensation resulting from reversible formation of N -phenylhydroxylamine. The initial TOF of 6,100 h−1 obtained after 10 min at 40 °C with 0.1 mol% 2 is among the highest to be reported for the metal nanoparticle catalysed reduction of nitrobenzene to N -phenylhydroxylamine and a significant improvement on 5 wt% Ru/C which gave a modest conversion of 21 % (initial TOF = 240 h−1) to a mixture of N -phenylhydroxylamine and aniline. A broad range of substituted N -aryl and N -heteroaryl nitroarenes were reduced to the corresponding N -arylhydroxylamine in high yield and with excellent selectivity by adjusting the reaction times. However, reduction of electron rich amino-substituted nitroarenes was extremely slow and resulted in reduction to the aniline with no evidence for the corresponding hydroxylamine. Complete reduction of amino substituted nitroarene is proposed to be facilitated by amine-assisted elimination of hydroxide from the hydroxylamine to afford a readily reducible quinondiimine-derived iminium intermediate that reacts with a surface hydride to liberate the amine. Under optimum conditions the catalyst could be reused five times for the reduction of nitrobenzene to N -phenylhydroxylamine with no detectable change in activity and only slight decrease in selectivity. [ABSTRACT FROM AUTHOR]

A collection of genomic DNA sequences of herpes simplex virus (HSV) strains has been defined and analyzed, and some information is available about genomic stability upon limited passage of viruses in culture. The nature of genomic change upon extensive laboratory passage remains to be determined. In this report we review the history of the HSV-1 KOS laboratory strain and the related KOS1.1 laboratory sub-strain, also called KOS (M), and determine the complete genomic sequence of an early passage stock of the KOS laboratory sub-strain and a laboratory stock of the KOS1.1 sub-strain. The genomes of the two sub-strains are highly similar with only five coding changes, 20 non-coding changes, and about twenty non-ORF sequence changes. The coding changes could potentially explain the KOS1.1 phenotypic properties of increased replication at high temperature and reduced neuroinvasiveness. The study also provides sequence markers to define the provenance of specific laboratory KOS virus stocks. [ABSTRACT FROM AUTHOR]

UL24 is conserved among all Herpesviridae . In herpes simplex virus 1 (HSV-1), UL24 mutations lead to reduced viral titers both in cell culture and in vivo , and reduced pathogenicity. The human cytomegalovirus ortholog of UL24 has a gene regulatory function; however, it is not known whether other UL24 orthologs also affect gene expression. We discovered that in co-transfection experiments, expression of UL24 correlated with a reduction in the expression of several viral proteins and transcripts. Substitution mutations targeting conserved residues in UL24 impaired this function. Reduced transcript levels did not appear attributable to changes in mRNA stability. The UL24 ortholog of Herpes B virus exhibited a similar activity. An HSV-1 mutant that does not express UL24 produced more viral R1 and R2 transcripts than the wild type or rescue virus relative to the amount of viral DNA. These results reveal a new role for HSV-1 UL24 in regulating viral mRNA accumulation. [ABSTRACT FROM AUTHOR]