Pietro Mercuri and René Schoof
Math. Comp. 89 (2020), 1969-1991.
Abstract, references and article information

Roberto Ferretti and Michel Mehrenberger
Math. Comp. 89 (2019), 1783-1805.
Abstract, references and article information

Takahito Kashiwabara and Tomoya Kemmochi
Math. Comp. 89 (2020), 1647-1679.
Abstract, references and article information

Ricardo G. Durán, Enrique Otárola and Abner J. Salgado
Math. Comp. 89 (2020), 1581-1603.
Abstract, references and article information

While only a small group of North Koreans have access to the global internet, usage patterns are changing among the elites of Pyongyang – with those in military intelligence circles now exhibiting stronger security chops, a report from Recorded Future has found

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

Jordi Pau and Antti Perälä
Trans. Amer. Math. Soc. 373 (2020), 3031-3062.
Abstract, references and article information

A. Ilyin and A. Laptev
St. Petersburg Math. J. 31 (2020), 479-493.
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Gregory J. Galloway and Hyun Chul Jang
Proc. Amer. Math. Soc. 148 (2020), 2617-2629.
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Véronique Bazier-Matte and Pierre-Guy Plamondon
Proc. Amer. Math. Soc. 148 (2020), 2397-2409.
Abstract, references and article information

Samuel Dagogo-Jack
Jan 1, 2002; 15:
Articles

The Hong Kong Special Administrative Region Government has rejected allegations made by certain officials and politicians in the United States, United Kingdom and European Parliament relating to an April 18 arrest operation and other security matters.

In a statement today, the Hong Kong SAR Government said such allegations were totally unfounded and amounted to a serious intervention in Hong Kong's affairs.

The SAR Government strongly disagreed with the grossly irresponsible remarks and expressed deep regret about them.

It pointed out that since its return to the Motherland, the HKSAR has maintained stability and prosperity under the principle of "one country, two systems", exercising "Hong Kong people administering Hong Kong" and a high degree of autonomy in strict accordance with the Basic Law (BL).   

"The Central Government has time and again reiterated that it will unswervingly implement the policy of one country, two systems' and make sure that it is fully applied in Hong Kong without being bent or distorted. 

“How to implement the policy in the HKSAR - an inalienable part of the People's Republic of China (BL Article 1) and a local administrative region of the People's Republic of China which shall enjoy a high degree of autonomy and come directly under the Central People's Government (BL Article 12) - are entirely internal affairs of the People's Republic of China.

“No other state has the right to intervene, directly or indirectly, in those internal affairs.”

The statement noted Hong Kong people enjoy extensive rights and freedoms which are enshrined in the Basic Law. Basic Law Article 4 states that the HKSAR shall safeguard the rights and freedoms of the residents and of other persons in the region in accordance with law. 

“In addition, human rights and freedoms in Hong Kong are fully protected by the Hong Kong Bill of Rights Ordinance and other legislation, and underpinned by an independent judiciary."

The SAR Government said it always respects and protects human rights and freedoms. Any allegation that there has been an erosion in freedoms enjoyed by Hong Kong people is unfounded.

However, these rights are not absolute. As pointed out by the Chief Justice of the Court of Final Appeal at the Ceremonial Opening of the Legal Year 2020: "It is important to understand that the enjoyment of these rights has limits so as not to affect adversely to an unacceptable level the enjoyment by other members of their community of their rights and liberties."

There are clear limits in the law as to the exercise of these rights. When the law is broken, action will be taken in accordance with the criminal justice system.

"We therefore take great exception to comments made by officials and politicians in foreign countries concerning the recent arrests and prosecution of a number of persons for organising and participating in unauthorised assemblies in Hong Kong. 

“The allegation by some that those arrests amounted to an attack on Hong Kong's freedoms and a breach of the BL is absurd and can hardly stand the test of any law-abiding jurisdiction," the statement emphasised.

It also pointed out that Basic Law Article 63 provides that "The Department of Justice of the Hong Kong Special Administrative Region shall control criminal prosecutions, free from any interference." 

Prosecutors have always been discharging this constitutional duty independently and professionally, without fear or favour. Prosecutorial decisions are based on an objective assessment of all admissible evidence and applicable laws, made strictly in accordance with the Prosecution Code which is available to the public.

Cases will not be handled any differently owing to the political beliefs or background of the persons involved.

When law enforcement agencies have completed their investigation, they would seek legal advice from the Department of Justice. The prosecutors would carefully consider the investigation reports and relevant materials submitted. A prosecution would only be commenced if the prosecutor is satisfied that there is sufficient admissible evidence to support a reasonable prospect of conviction.

In short, the well-established procedures of Hong Kong's criminal justice system include the independent investigations by law enforcement agencies, the independent prosecutorial decisions based on the objective assessment of evidence, applicable laws and in accordance with the Prosecution Code, and finally, open trials by an independent judiciary. 

"The guarantee of judicial independence is explicitly set out in the BL and the quality of the judgments of our courts contributes to the much respected judiciary and rule of law in the HKSAR.

"We therefore note with abhorrence certain overseas politicians' request that the HKSAR Government should drop the charges against the arrested individuals. If we were to accede or to be seen to yield to such unreasonable demands, we would not only be unfair and unprofessional but would also act in violation of the spirit of the rule of law – a core value in Hong Kong," the statement added.

The SAR Government remains steadfast to uphold the rule of law. The latest Rule of Law Index 2020 released by the World Justice Project, in which Hong Kong maintains its ranking as No. 5 in the East Asia and Pacific Region and No. 16 globally, several places ahead of the United States, has clearly affirmed Hong Kong's commitment.

On legislating for Basic Law Article 23, the statement said, "The HKSAR Government has the constitutional duty to ensure that the necessary legislation is in place to safeguard national security.

“Having laws in place to protect national security is common in many jurisdictions, and we do not see how any defence of sovereignty and security by a jurisdiction would impact on its local and overseas investment. 

“Coincidentally, it is relevant to note security issues arising from the social unrest last year were part of the causes affecting Hong Kong's score under 'Investment Freedom' according to the US-based Heritage Foundation 2020 Index of Economic Freedom."

As regards enquiries about the role of the Hong Kong & Macao Affairs Office of the State Council (HKMAO) and the Liaison Office of the Central People's Government (LOCPG) in the HKSAR, they represent the Central People's Government to which the HKSAR comes directly under pertaining to Basic Law Article 12. 

These offices have the power and responsibility over the proper and full implementation of the Basic Law and "one country, two systems" in Hong Kong.

It is therefore clearly legitimate for the HKMAO and LOCPG to recently express their concerns over the prolonged paralysis of the Legislative Council House Committee, thereby hindering LegCo's performance of its legislative functions under the Basic Law.

"Any suggestion that those legitimate remarks by the HKMAO and the LOCPG amount to interference only illustrates an ignorance of the constitutional order of the HKSAR and its relationship with the Central Authorities," the SAR Government added.

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

Roadside Stations: 2 (Health Risk: Low)

(Rice University) Rice University researchers have integrated high-efficiency solar cells and electrode catalysts into an efficient, low-cost device that splits water to produce hydrogen fuel.

(College of Engineering, Carnegie Mellon University) Carnegie Mellon University's Maarten de Boer and Gianluca Piazza are developing reliable, mechanical switches the size of a DNA molecule, thanks to a $2M LEAP-HI grant from the National Science Foundation.

(Johannes Gutenberg Universitaet Mainz) Scientists at Johannes Gutenberg University Mainz (JGU) and the Helmholtz Institute Mainz (HIM) in Germany have presented a non-contact method for detecting the state of charge and any defects in lithium-ion batteries.

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

β-Glucocerebrosidase (GBA) hydrolyzes glucosylceramide (GlcCer) to generate ceramide. Previously, we demonstrated that lysosomal GBA1 and nonlysosomal GBA2 possess not only GlcCer hydrolase activity, but also transglucosylation activity to transfer the glucose residue from GlcCer to cholesterol to form β-cholesterylglucoside (β-GlcChol) in vitro. β-GlcChol is a member of sterylglycosides present in diverse species. How GBA1 and GBA2 mediate β-GlcChol metabolism in the brain is unknown. Here, we purified and characterized sterylglycosides from rodent and fish brains. Although glucose is thought to be the sole carbohydrate component of sterylglycosides in vertebrates, structural analysis of rat brain sterylglycosides revealed the presence of galactosylated cholesterol (β-GalChol), in addition to β-GlcChol. Analyses of brain tissues from GBA2-deficient mice and GBA1- and/or GBA2-deficient Japanese rice fish (Oryzias latipes) revealed that GBA1 and GBA2 are responsible for β-GlcChol degradation and formation, respectively, and that both GBA1 and GBA2 are responsible for β-GalChol formation. Liquid chromatography–tandem MS revealed that β-GlcChol and β-GalChol are present throughout development from embryo to adult in the mouse brain. We found that β-GalChol expression depends on galactosylceramide (GalCer), and developmental onset of β-GalChol biosynthesis appeared to be during myelination. We also found that β-GlcChol and β-GalChol are secreted from neurons and glial cells in association with exosomes. In vitro enzyme assays confirmed that GBA1 and GBA2 have transgalactosylation activity to transfer the galactose residue from GalCer to cholesterol to form β-GalChol. This is the first report of the existence of β-GalChol in vertebrates and how β-GlcChol and β-GalChol are formed in the brain.

Mammalian cytochrome P450 enzymes often metabolize many pharmaceuticals and other xenobiotics, a feature that is valuable in a biotechnology setting. However, extant P450 enzymes are typically relatively unstable, with T50 values of ∼30–40 °C. Reconstructed ancestral cytochrome P450 enzymes tend to have variable substrate selectivity compared with related extant forms, but they also have higher thermostability and therefore may be excellent tools for commercial biosynthesis of important intermediates, final drug molecules, or drug metabolites. The mammalian ancestor of the cytochrome P450 1B subfamily was herein characterized structurally and functionally, revealing differences from the extant human CYP1B1 in ligand binding, metabolism, and potential molecular contributors to its thermostability. Whereas extant human CYP1B1 has one molecule of α-naphthoflavone in a closed active site, we observed that subtle amino acid substitutions outside the active site in the ancestor CYP1B enzyme yielded an open active site with four ligand copies. A structure of the ancestor with 17β-estradiol revealed only one molecule in the active site, which still had the same open conformation. Detailed comparisons between the extant and ancestor forms revealed increases in electrostatic and aromatic interactions between distinct secondary structure elements in the ancestral forms that may contribute to their thermostability. To the best of our knowledge, this represents the first structural evaluation of a reconstructed ancestral cytochrome P450, revealing key features that appear to contribute to its thermostability.

S-Palmitoylation is a reversible post-translational lipid modification that dynamically regulates protein functions. Voltage-gated sodium channels are subjected to S-palmitoylation and exhibit altered functions in different S-palmitoylation states. Our aim was to investigate whether and how S-palmitoylation regulates Nav1.6 channel function and to identify S-palmitoylation sites that can potentially be pharmacologically targeted. Acyl-biotin exchange assay showed that Nav1.6 is modified by S-palmitoylation in the mouse brain and in a Nav1.6 stable HEK 293 cell line. Using whole-cell voltage clamp, we discovered that enhancing S-palmitoylation with palmitic acid increases Nav1.6 current, whereas blocking S-palmitoylation with 2-bromopalmitate reduces Nav1.6 current and shifts the steady-state inactivation in the hyperpolarizing direction. Three S-palmitoylation sites (Cys1169, Cys1170, and Cys1978) were identified. These sites differentially modulate distinct Nav1.6 properties. Interestingly, Cys1978 is exclusive to Nav1.6 among all Nav isoforms and is evolutionally conserved in Nav1.6 among most species. Cys1978 S-palmitoylation regulates current amplitude uniquely in Nav1.6. Furthermore, we showed that eliminating S-palmitoylation at specific sites alters Nav1.6-mediated excitability in dorsal root ganglion neurons. Therefore, our study reveals S-palmitoylation as a potential isoform-specific mechanism to modulate Nav activity and neuronal excitability in physiological and diseased conditions.

The cellular energy sensor AMP-activated protein kinase (AMPK) is a metabolic regulator that mediates adaptation to nutritional variations to maintain a proper energy balance in cells. We show here that suckling-weaning and fasting-refeeding transitions in rodents are associated with changes in AMPK activation and the cellular energy state in the liver. These nutritional transitions were characterized by a metabolic switch from lipid to glucose utilization, orchestrated by modifications in glucose levels and the glucagon/insulin ratio in the bloodstream. We therefore investigated the respective roles of glucose and pancreatic hormones on AMPK activation in mouse primary hepatocytes. We found that glucose starvation transiently activates AMPK, whereas changes in glucagon and insulin levels had no impact on AMPK. Challenge of hepatocytes with metformin-induced metabolic stress strengthened both AMPK activation and cellular energy depletion under limited-glucose conditions, whereas neither glucagon nor insulin altered AMPK activation. Although both insulin and glucagon induced AMPKα phosphorylation at its Ser485/491 residue, they did not affect its activity. Finally, the decrease in cellular ATP levels in response to an energy stress was additionally exacerbated under fasting conditions and by AMPK deficiency in hepatocytes, revealing metabolic inflexibility and emphasizing the importance of AMPK for maintaining hepatic energy charge. Our results suggest that nutritional changes (i.e. glucose availability), rather than the related hormonal changes (i.e. the glucagon/insulin ratio), sensitize AMPK activation to the energetic stress induced by the dietary transition during fasting. This effect is critical for preserving the cellular energy state in the liver.

The Agriculture, Fisheries & Conservation Department (AFCD) and the Leisure & Cultural Services Department (LCSD) announced today that some of their facilities will be closed in light of the latest developments of COVID-19.

Country park barbecue sites and campsites of the AFCD will be closed from 6pm on March 28 for 14 days. There are 163 barbecue sites and 41 campsites under the management of the AFCD.

During the closure of these facilities, barbecue or camping activities in country parks will not be allowed and AFCD staff will step up patrols of the sites concerned and take appropriate action against any violation of relevant regulations.

Call 1823 for enquiries and visit the Enjoy Hiking website for updates on country park facilities.

As for LCSD facilities, its free outdoor leisure facilities will be closed from 6pm on March 28.

Other venues and facilities with services already suspended will continue to be closed until further notice.

All booking applications for the department's recreation and sports facilities, wedding venues, amphitheatres and non-fee charging leisure venues for non-designated use are also suspended.

Meanwhile, the Housing Authority will close its outdoor sports and recreational facilities from 6pm tomorrow until further notice.