Reconstruction of pre-monsoon weather conditions in northwestern Thailand from the tree-ring widths of Pinus merkusii and Pinus kesiya

Two pine species, Pinus merkusii and Pinus kesiya, native in Thailand were studied for their potential to reconstruct past weather conditions from their tree rings. Altogether, cores from 209 Merkus pines and from 205 Khasi pines were sampled at 16 sites. Standard methods were applied to assemble tree-ring chronologies for each site and tree species. The longest site chronology of Merkus pine and Khasi pine covered 314 and 183 years, respectively. Principal component analysis (PCA) illustrated a close clustering of all, except two, site chronologies on the PC1 axis, indicating a strong signal common for both pine species throughout NW Thailand. However, along the PC2 axis, there was a distinct separation between the Merkus pine and the Khasi pine site chronologies, which was possibly due to the species-specific differences in site altitudes. Simple correlations between the PC1 time series and a regionalized climate data set showed a highly negative association with temperature during the pre-monsoon period from March to May. Since, pre-monsoon temperature and rainfall were negatively correlated with each other, we used the PC1 as a direct proxy for pre-monsoon weather conditions (warm/dry vs. cool/wet) back to 1834 AD.     

Strategies to Guide the Return of Genomic Research Findings: An Australian Perspective

In Australia, along with many other countries, limited guidance or other support strategies are currently available to researchers, institutional research ethics committees, and others responsible for making decisions about whether to return genomic findings with potential value to participants or their blood relatives. This lack of guidance results in onerous decision-making burdens—traversing technical, interpretative, and ethical dimensions—as well as uncertainty and inconsistencies for research participants. This article draws on a recent targeted consultation conducted by the Australian National Health and Medical Research Council to put forward strategies for supporting return of finding decision-making. In particular, we propose a pyramid of decision-making support: decision-making guidelines, technical and interpretative assistance, and ethical assistance for intractable “tough” cases. Each step of the pyramid involves an increasing level of regulatory involvement and applies to a smaller subsection of genomic research findings. Implementation of such strategies would facilitate a growing evidence base for return of finding decisions, thereby easing the financial, time, and moral burdens currently placed on researchers and other relevant decision-makers while also improving the quality of such decisions and, consequently, participant outcomes.     

Incorporation of terminal phosphorothioates into oligonucleotides.

Considerable effort has been directed towards studying the structure and function of oligonucleotides and several approaches rely on the attachment of reporter groups to oligonucleotides. We report here the introduction of 3'- and 5'-terminal phosphorothioates into heptameric oligonucleotides and their post-synthetic modification with several reporter groups. The synthesis of terminal phosphorothioates is based on the coupling of a ribonucleoside phosphoramidite at the first or last nucleotide, respectively, which, after sulphurization, is removed by sequential oxidation of the vicinal hydroxyl groups and then beta-elimination. Product formation is of the order of 95%. The ratio of phosphorothioate- versus phosphate-terminated oligodeoxynucleotides as analysed by electrophoresis on a Hg2+gel is in general 85/15. Examples for the reactivity of the terminal phosphorothioates for conjugation with cholesterol, bimane and for sulphydryl exchange are described.