Quanlei Fang and Jingbo Xia
Proc. Amer. Math. Soc. 148 (2020), 2497-2507.
Abstract, references and article information

Qingying Bu
Proc. Amer. Math. Soc. 148 (2020), 2459-2467.
Abstract, references and article information

The deadline for applications under the first round of funding from the Elder Academy Development Foundation in 2020 has been extended to June 30, the Labour & Welfare Bureau announced today.

The decision aims to provide sufficient time for primary and secondary school sponsoring bodies, post-secondary institutions and organisations, which may be affected by the COVID-19 epidemic, to prepare their submissions.

The fund’s committee accepts funding applications all year round and conducts vetting and disburses funding twice a year. The deadlines were generally May 31 and October 31 respectively.

The committee will continue to monitor the situation and announce arrangements for the next round in due course.

To tie in with the Elder Academy Scheme, the fund mainly provides funding for primary and secondary schools as well as post-secondary institutions to set up academies to provide learning opportunities in a school setting for the elderly.

Funding is also provided for activities that encourage elderly learning and inter-generational harmony.

Call 3655 5861 or 3655 5007 for enquiries.

About $31 million in funding has been given to support 79 projects under the special round of the Public Policy Research (PPR) Funding Scheme, the Government announced today.

A total of 210 applications were received for the special round, which was launched last November to fund local research institutions and think tanks to research topics relating to the underlying causes of the social incidents that took place in the second half of 2019.

The research may also cover important political, economic, cultural and societal issues relating to deep-seated problems of society.

Assessment of the applications received under the special round was conducted by the independent assessment panel chaired by and comprising experienced academics.

The research quality of the proposal and relevance to the themes of the special round were the principal assessment criteria, with consideration given to factors such as whether the research proposal was solution-oriented, feasible and practical, whether the methodology was reasonable and sound, the applicant’s capability and whether the proposed budget was cost-effective. 

The assessment panel took a holistic view on each research proposal, reached a collective decision and made recommendations, the Policy Innovation & Co-ordination Office said, adding that a declaration of interest system was in place to ensure the assessments were fair and impartial.

In general, a sum of up to $500,000 has been granted to each approved project under the special round.

The approved projects have commenced progressively and are expected to be completed by the end of the year, with the first batch to be completed in late September to early October.

Click here for details of the funded projects.

General Stations: 1 to 2 (Health Risk: Low)

Roadside Stations: 2 (Health Risk: Low)

(Fundação de Amparo à Pesquisa do Estado de São Paulo) Thanks to its magnetic properties, the material -- zinc-doped manganese chromite -- can be used in a range of products, from gas sensors to data storage devices.

The dextransucrase DSR-OK from the Gram-positive bacterium Oenococcus kitaharae DSM17330 produces a dextran of the highest molar mass reported to date (∼109 g/mol). In this study, we selected a recombinant form, DSR-OKΔ1, to identify molecular determinants involved in the sugar polymerization mechanism and that confer its ability to produce a very-high-molar-mass polymer. In domain V of DSR-OK, we identified seven putative sugar-binding pockets characteristic of glycoside hydrolase 70 (GH70) glucansucrases that are known to be involved in glucan binding. We investigated their role in polymer synthesis through several approaches, including monitoring of dextran synthesis, affinity assays, sugar binding pocket deletions, site-directed mutagenesis, and construction of chimeric enzymes. Substitution of only two stacking aromatic residues in two consecutive sugar-binding pockets (variant DSR-OKΔ1-Y1162A-F1228A) induced quasi-complete loss of very-high-molar-mass dextran synthesis, resulting in production of only 10–13 kg/mol polymers. Moreover, the double mutation completely switched the semiprocessive mode of DSR-OKΔ1 toward a distributive one, highlighting the strong influence of these pockets on enzyme processivity. Finally, the position of each pocket relative to the active site also appeared to be important for polymer elongation. We propose that sugar-binding pockets spatially closer to the catalytic domain play a major role in the control of processivity. A deep structural characterization, if possible with large-molar-mass sugar ligands, would allow confirming this hypothesis.

Knowledge of the molecular events in mitochondrial DNA (mtDNA) replication is crucial to understanding the origins of human disorders arising from mitochondrial dysfunction. Twinkle helicase is an essential component of mtDNA replication. Here, we employed atomic force microscopy imaging in air and liquids to visualize ring assembly, DNA binding, and unwinding activity of individual Twinkle hexamers at the single-molecule level. We observed that the Twinkle subunits self-assemble into hexamers and higher-order complexes that can switch between open and closed-ring configurations in the absence of DNA. Our analyses helped visualize Twinkle loading onto and unloading from DNA in an open-ringed configuration. They also revealed that closed-ring conformers bind and unwind several hundred base pairs of duplex DNA at an average rate of ∼240 bp/min. We found that the addition of mitochondrial single-stranded (ss) DNA–binding protein both influences the ways Twinkle loads onto defined DNA substrates and stabilizes the unwound ssDNA product, resulting in a ∼5-fold stimulation of the apparent DNA-unwinding rate. Mitochondrial ssDNA-binding protein also increased the estimated translocation processivity from 1750 to >9000 bp before helicase disassociation, suggesting that more than half of the mitochondrial genome could be unwound by Twinkle during a single DNA-binding event. The strategies used in this work provide a new platform to examine Twinkle disease variants and the core mtDNA replication machinery. They also offer an enhanced framework to investigate molecular mechanisms underlying deletion and depletion of the mitochondrial genome as observed in mitochondrial diseases.