66 research outputs found
Informing the future of Australian mining through climate change scenarios
Abstract: Mining value chains are vulnerable to a changing climate mainly due to the likelihood of increases in the incidence of extreme weather events. As such events will potentially become more frequent and more intense, the associated impacts such as infrastructure damage, production delays and downtime may damage mine profitability, staff safety, company reputation, regional 'liveability' and government revenues. Mining adaptation strategies to better deal with such impacts can be developed but the options available cannot simply be applied 'across the board' at all mines and in all situations. Various types of mining in Australia occur across 11 main geographic areas, each with its own processes and needs, its own climate signature and its own extreme-event profile. To provide some context for the likely changes in future climate, CSIRO has developed mining region-specific scenarios in association with the OzClim Climate Change Scenario Generator. OzClim generates climate change scenarios using pattern scaling where the change at a particular grid point is normalised by the mean global warming produced by the model for a doubled CO 2 concentration in the atmosphere. The patterns of change are produced for each of the 23 global climate models and for the purposes of the Australian mining regions, we have expressed changes consistent with an historical baseline in order to make the projection information as contextually relevant as possible. To bridge the gap between scenarios and users, CSIRO facilitated workshop events in mining regions. Representatives of a cross-section of the mining chain (including energy, mining, transport, research, water and community stakeholders) were invited to attend, some of whom were first interviewed by facilitators to gain an insight into their operations, understandings, and needs with regard to the workshop. The attendees were presented with future regional climate scenarios, additional information from other studies and climate location analogues helping to further 'set the scene' for the future and helping to facilitate discussion around potential impacts and adaptation needs. Discussions at the workshops provided the means for the scenarios to be placed in their local context, whilst hearing how others in the chain may be directly and indirectly impacted and how they may adapt. Mines and their related infrastructure are frequently long-term investments for all concerned. Therefore, future climate scenarios are valuable for mining value chains and the decision-makers to envisage and plan the future, including adaptation at established sites, alternative processes at new sites and contingency plans that accommodate new levels of variability. Utilising workshops to link future climate scenarios to the value chain and its operational components assisted the end-users to visualise, conceptualise and engage with adaptation decision-making scenarios. The event also brought together participants from different parts of the mining chain who were able to share knowledge and discuss needs that may in the future aid adaptation and avoid maladaptation
Characterization of yeast strains with conditionally expressed variants of ribosomal protein genes tcm1 and cyh2.
We placed a regulatory sequence derived from the GAL10 locus of Saccharomyces cerevisiae at various distances from the start sites of transcription of two yeast ribosomal protein genes, tcm1 and cyh2. The hybrid ribosomal protein genes were transcribed at wild-type levels in the presence of galactose. In the absence of galactose, the hybrid genes were transcribed either at a reduced level or essentially not at all. Yeast cells which transcribe the ribosomal protein genes at a reduced rate continued to grow, suggesting that enhanced translation of the ribosomal protein mRNA may permit an adequate rate of synthesis of the corresponding protein. Consistent with this suggestion is the finding that preexisting mRNA decayed at a reduced rate when transcription was halted abruptly by removal of galactose. Yeast cells unable to transcribe tcm1 or cyh2 without galactose did not grow. These conditional lethal strains demonstrate that the ribosomal proteins encoded by tcm1 and cyh2 are essential; furthermore, these strains are potentially useful for isolating mutations in the tcm1 and cyh2 proteins affecting their transport, assembly, or function
Structural Diversity in Bacterial Ribosomes: Mycobacterial 70S Ribosome Structure Reveals Novel Features
Here we present analysis of a 3D cryo-EM map of the 70S ribosome from Mycobacterium smegmatis, a saprophytic cousin of the etiological agent of tuberculosis in humans, Mycobacterium tuberculosis. In comparison with the 3D structures of other prokaryotic ribosomes, the density map of the M. smegmatis 70S ribosome reveals unique structural features and their relative orientations in the ribosome. Dramatic changes in the periphery due to additional rRNA segments and extra domains of some of the peripheral ribosomal proteins like S3, S5, S16, L17, L25, are evident. One of the most notable features appears in the large subunit near L1 stalk as a long helical structure next to helix 54 of the 23S rRNA. The sharp upper end of this structure is located in the vicinity of the mRNA exit channel. Although the M. smegmatis 70S ribosome possesses conserved core structure of bacterial ribosome, the new structural features, unveiled in this study, demonstrates diversity in the 3D architecture of bacterial ribosomes. We postulate that the prominent helical structure related to the 23S rRNA actively participates in the mechanisms of translation in mycobacteria
Two MC1R loss-of-function alleles in cream-coloured Australian Cattle Dogs and white Huskies.
Loss-of-function variants in the MC1R gene cause recessive red or yellow coat-colour phenotypes in many species. The canine MC1R:c.916C>T (p.Arg306Ter) variant is widespread and found in a homozygous state in many uniformly yellow- or red-coloured dogs. We investigated cream-coloured Australian Cattle Dogs whose coat colour could not be explained by this variant. A genome-wide association study with 10 cream and 123 red Australian Cattle Dogs confirmed that the cream locus indeed maps to MC1R. Whole-genome sequencing of cream dogs revealed a single nucleotide variant within the MITF binding site of the canine MC1R promoter. We propose to designate the mutant alleles at MC1R:c.916C>T as e1 and at the new promoter variant as e2. Both alleles segregate in the Australian Cattle Dog breed. When we considered both alleles in combination, we observed perfect association between the MC1R genotypes and the cream coat colour phenotype in a cohort of 10 cases and 324 control dogs. Analysis of the MC1R transcript levels in an e /e compound heterozygous dog confirmed that the transcript levels of the e2 allele were markedly reduced with respect to the e1 allele. We further report another MC1R loss-of-function allele in Alaskan and Siberian Huskies caused by a 2-bp deletion in the coding sequence, MC1R:c.816_817delCT. We propose to term this allele e3. Huskies that carry two copies of MC1R loss-of-function alleles have a white coat colour
A novel translation initiation region from Mycoplasma genitalium that functions in Escherichia coli.
The tuf gene of Mycoplasma genitalium uses a signal other than a Shine-Dalgarno sequence to promote translation initiation. We have inserted the translation initiation region of this gene in front of the Escherichia coli lacZ gene and shown that it is recognized by the translational machinery of E. coli; the signal operates in vivo at roughly the same efficiency as a synthetic Shine-Dalgarno sequence. The M. genitalium sequence was also used to replace the native translation initiation region of the cat gene. When assayed in E. coli, the M. genitalium sequence is equivalent to a Shine-Dalgarno sequence in stimulating translation of this mRNA also. Site-directed mutagenesis enabled us to identify some of the bases that comprise the functional sequence. We propose that the sequence UUAACAACAU functions as a ribosome binding site by annealing to nucleotides 1082-1093 of the E. coli 16S rRNA. The activity of this sequence is enhanced when it is present in the loop of a stem-and-loop structure. Additional sequences both upstream and downstream of the initiation codon are also involved, but their role has not been elucidated
Nucleotide sequence of the tuf gene from Mycoplasma genitalium.
A 2.6-kilobase HindIII fragment from MycoRlasma genitalium (ATCC
33530) was completely sequenced and found to contain an open
reading frame coding for a protein of 393 amino acids. The
nucleotide sequence is 76% homologous with tuf from M.
gallisepticum (see accompanying paper), while the amino acid
sequence shows 81% identity (with conservative replacements) with
the EF-Tu of Escherichia coli tufB (1). Southern blot
hybridization shows that M. genitalium contains a single copy of
tuf. Although the tuf gene is followed by sequences which could
signal termination of transcription, there is no Shine-Dalgarno
(ribosome binding site) sequence nor another open reading frame
in the region 5' to tuf. Studies showing that sequences upstream
of this gene are capable of functioning as a translation
initiator in E. coli will be published elsewhere
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