Jungang Li, Guozhen Lu and Qiaohua Yang
Trans. Amer. Math. Soc. 373 (2020), 3483-3513.
Abstract, references and article information

A. Ilyin and A. Laptev
St. Petersburg Math. J. 31 (2020), 479-493.
Abstract, references and article information

Véronique Bazier-Matte and Pierre-Guy Plamondon
Proc. Amer. Math. Soc. 148 (2020), 2397-2409.
Abstract, references and article information

On this last Sunday of 2019, I wish every Hong Kong citizen a warm, peaceful and hopeful year 2020.

A New Year holds welcome promises of a fresh start and a new beginning. The New Year is also traditionally a time for planning, greeting, reminiscing as well as some soul and heart searching.

I believe that many of you would share my feeling that the year 2019 has been a year of unremitting shocks and turbulence to our community and our economy. Indeed, it has been a severely testing time for all in Hong Kong.

It all began with the introduction into the Legislative Council of the bill to amend the Fugitive Offenders Ordinance in April. Responding to strong public sentiment, the Government suspended all work on the bill in mid-June and declared its death in early July. On September 4, the Chief Executive announced the bill's withdrawal. This was done on October 23 when the Legislative Council resumed normal business.

Despite this, the public protests which began as largely peaceful and orderly marches in June soon got out of control. Unprecedented violence and reckless destruction became the norm. Radical protesters attacked police officers as well as police stations and facilities with petrol bombs, iron bars, bricks and chemicals. Some even used high-tension slingshots, bows and arrows. During the past six months or so, over 2,600 people were injured in the social unrest, including over 500 police officers.

Meanwhile, public infrastructure and transport including a cumulative total of 85 heavy rail stations and 62 light rail stations, as well as countless shops, restaurants and shopping malls had been repeatedly vandalised. More so, nearly 21,000 square metres of paving blocks from footpaths were ripped up and used as weapons to attack Police. Over 52,000 metres of roadside railing were removed and 740 sets of traffic lights destroyed.

Last month, masked protesters battered the Hung Hom Cross-Harbour Tunnel, shutting it down for two full weeks. This vital city artery normally carries 110,000 vehicles a day, accounting for some 43% of the daily cross-harbour vehicular flow. It took a total of 800 government staff and contractor's workers some 100 hours to carry out emergency repair round-the-clock before the tunnel could be reopened. At the same time, nearby Polytechnic University was overrun by radical protesters. The same happened to the Chinese University.

Apart from recklessly damaging our universities, violent protesters turned the two campuses into arsenals on a frightening scale. When the last of the protesters finally left the universities, Police seized altogether nearly 8,000 petrol bombs plus numerous explosives, hundreds of bottles of corrosive liquid and weapons of all sorts.

This level of premeditated and organised destruction and violence could hardly be tolerated in any country or economy that upholds the rule of law. Hong Kong, I am proud to say, is among those economies that believe passionately in the primacy of rule of law. It safeguards our economy, our community, our families and our way of life.

In fact, the rule of law is among Hong Kong's much cherished core values, alongside our fiercely independent judiciary, clean government, level playing field for business and enviable freedoms. These freedoms, as enshrined in the Basic Law and the Hong Kong Bill of Rights Ordinance, include freedom of speech, of the press and free flow of information; freedom of association and assembly; free trade and free port; free flow of capital; freely convertible currency; freedom of religious belief and free education. We have also been the freest economy in the world continuously for 25 years. The unique "one country, two systems" formula has been functioning well and we enjoy the best of both worlds.

Despite the recent social unrest which has affected our economy and labour market, Hong Kong's institutional strengths remain robust and intact. Our fundamentals stay sound and strong. We still enjoy a high rating in various areas by international think tanks and agencies. Allow me to say that whilst Hong Kong may not have the full semblance of Western democracy, we do enjoy for a very long time the full substance of real freedom which underpins Hong Kong's success.

Over the past six months, most of the requests for public meetings, processions and protests were given the greenlight by Police. During these public events, be it small or large, Police had dutifully facilitated and ensured the safety of protesters and other road users. When the requests were not approved, it was generally a decision made in the hopes of preventing violence, ensuring peace and public order, as our society has every right to expect of its police and its government.

On November 24, we witnessed a peaceful and orderly District Council Election with a record high turnout and voting rates. My colleagues and I are looking forward to working with all new District Council members. We also look forward to expanding our dialogue with the community. While we will continue to engage different sectors of society through our usual channels, the Government will broaden and rejuvenate our communication with the public. Less than two weeks ago and after the one by the Chief Executive in September, my Principal Official colleagues have started a dialogue with the public through Facebook live. You will certainly see more of us listening and responding to people's views and concerns on these and other communication channels in the coming year.

We are also establishing an Independent Review Committee comprising experts and community leaders. The committee will look into the causes and full circumstances of the social unrest and probe into Hong Kong's deep-seated social conflicts, from affordable housing, land supply, wealth gap, upward social mobility and opportunities for our young people to social justice. The committee will recommend ways to address the real and long-entrenched community concerns that underlie the discord.

Meanwhile, our economy is inevitably affected by the twin blows of social unrest and the trade dispute between the United States and the Mainland. Businesses and people of Hong Kong are yearning for the restoration of peace and order soonest possible, and the recovery of our economy.

In response, the Government has launched four rounds of relief measures since August. These added up to more than $25 billion. A number of the measures which will benefit grassroots families and small and medium enterprises will be implemented at the beginning of the New Year.

These relief measures would not solve our economic problems. Yet, they could help businesses and people of Hong Kong stay afloat while we strive to heal our divided community and battered economy.

There are deep-seated issues that we must acknowledge and resolve if we are to end the prolonged social unrest that has shaken the familiar Hong Kong which we all love and cherish. We must be patient and perseverant in helping our city to heal, one step at a time.

The past six months have been tough for us, but we will soldier on. Hong Kong is a remarkably resilient and resourceful international city with a strong can-do spirit. We have a New Year waiting for us. We have new and expanded channels of communication opened up for us. We expect the first report of the Independent Police Complaints Council to come out soon. And we have research and concrete recommendations of the Independent Review Committee ahead of us. Working together, I am confident that we can rebuild, reclaim and rejuvenate the remarkably resilient spirit of Hong Kong.

On this note, I wish all of you a New Year blessed with peace, harmony and goodwill.

Chief Secretary Matthew Cheung gave these remarks on RTHK's "Letter to Hong Kong" programme aired on December 29.

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

Roadside Stations: 2 (Health Risk: Low)

(University of Science and Technology of China) Researchers from University of science and technology of China has shed new lights on the topic of solid-phase ion migration. Researchers demonstrated a unique in-situ strategy for visualizing the dynamic solid-phase ion migration between nanostructures with nanogap at the atomic scale. The research article entitled "Real-Time Visualization of Solid-Phase Ion Migration Kinetics on Nanowire Monolayer" was published in Journal of the American Chemical Society on April 29th.

Claus Sorensen
Represent. Theory 24 (2020), 151-177.
Abstract, references and article information

The transcription factor forkhead box P3 (FOXP3) is a biomarker for regulatory T cells and can also be expressed in cancer cells, but its function in cancer appears to be divergent. The role of hepatocyte-expressed FOXP3 in hepatocellular carcinoma (HCC) is unknown. Here, we collected tumor samples and clinical information from 115 HCC patients and used five human cancer cell lines. We examined FOXP3 mRNA sequences for mutations, used a luciferase assay to assess promoter activities of FOXP3's target genes, and employed mouse tumor models to confirm in vitro results. We detected mutations in the FKH domain of FOXP3 mRNAs in 33% of the HCC tumor tissues, but in none of the adjacent nontumor tissues. None of the mutations occurred at high frequency, indicating that they occurred randomly. Notably, the mutations were not detected in the corresponding regions of FOXP3 genomic DNA, and many of them resulted in amino acid substitutions in the FKH region, altering FOXP3's subcellular localization. FOXP3 delocalization from the nucleus to the cytoplasm caused loss of transcriptional regulation of its target genes, inactivated its tumor-inhibitory capability, and changed cellular responses to histone deacetylase (HDAC) inhibitors. More complex FKH mutations appeared to be associated with worse prognosis in HCC patients. We conclude that mutations in the FKH domain of FOXP3 mRNA frequently occur in HCC and that these mutations are caused by errors in transcription and are not derived from genomic DNA mutations. Our results suggest that transcriptional mutagenesis of FOXP3 plays a role in HCC.

Prevention of aberrant cutaneous wound repair and appropriate regeneration of an intact and functional integument require the coordinated timing of fibroblast and keratinocyte migration. Here, we identified a mechanism whereby opposing cell-specific motogenic functions of a multifunctional intracellular and extracellular protein, the receptor for hyaluronan-mediated motility (RHAMM), coordinates fibroblast and keratinocyte migration speed and ensures appropriate timing of excisional wound closure. We found that, unlike in WT mice, in Rhamm-null mice, keratinocyte migration initiates prematurely in the excisional wounds, resulting in wounds that have re-surfaced before the formation of normal granulation tissue, leading to a defective epidermal architecture. We also noted aberrant keratinocyte and fibroblast migration in the Rhamm-null mice, indicating that RHAMM suppresses keratinocyte motility but increases fibroblast motility. This cell context–dependent effect resulted from cell-specific regulation of extracellular signal-regulated kinase 1/2 (ERK1/2) activation and expression of a RHAMM target gene encoding matrix metalloprotease 9 (MMP-9). In fibroblasts, RHAMM promoted ERK1/2 activation and MMP-9 expression, whereas in keratinocytes, RHAMM suppressed these activities. In keratinocytes, loss of RHAMM function or expression promoted epidermal growth factor receptor–regulated MMP-9 expression via ERK1/2, which resulted in cleavage of the ectodomain of the RHAMM partner protein CD44 and thereby increased keratinocyte motility. These results identify RHAMM as a key factor that integrates the timing of wound repair by controlling cell migration.