Maria Bras-Amorós and Julio Fernández-González
Math. Comp. 89 (2020), 2017-2030.
Abstract, references and article information

Yuji Nakatsukasa
Math. Comp. 89 (2020), 1843-1866.
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

The new rule, which will force payments platforms and online retailers to strongly authenticate purchases of £28 or more has been delayed by another six months amidst the COVID-19 pandemic

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

S. S. Lohvinenko and K. V. Ralchenko
Theor. Probability and Math. Statist. 99 (2020), 149-168.
Abstract, references and article information

A. V. Ivanov and I. K. Matsak
Theor. Probability and Math. Statist. 99 (2020), 91-99.
Abstract, references and article information

T. Bodnar, S. Mazur, S. Muhinyuza and N. Parolya
Theor. Probability and Math. Statist. 99 (2020), 39-52.
Abstract, references and article information

Theor. Probability and Math. Statist. 99 (2020), 1-3.
Abstract, references and article information

James Walsh
Proc. Amer. Math. Soc. 148 (2020), 2645-2654.
Abstract, references and article information

Moacir Aloisio, Silas L. Carvalho and César R. de Oliveira
Proc. Amer. Math. Soc. 148 (2020), 2509-2523.
Abstract, references and article information

Tonie Fares and Pascal Lefèvre
Proc. Amer. Math. Soc. 148 (2020), 2487-2496.
Abstract, references and article information

S. Waleed Noor and Osmar R. Severiano
Proc. Amer. Math. Soc. 148 (2020), 2469-2476.
Abstract, references and article information

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

The onset of COVID-19 has severely affected our economy and the legal sector was not spared. I have discussed with some of the representatives from the industry and we have carefully considered their suggestions with relevant government departments.

On Wednesday, the Government announced another package of measures to support individuals and businesses affected by COVID-19. Two of the measures are relevant to the legal sector: the establishment of LawTech Fund and the COVID-19 Online Dispute Resolution (ODR) Scheme. Today, I would like to share with you the arrangement of the LawTech Fund.

The Government always attaches great importance to LawTech. In her 2018 Policy Address, the Chief Executive supported the development of an online platform by non-government organisations to facilitate the provision of efficient and cost-effective online dispute resolution services in Hong Kong. The Government would allocate funding for the development of this project.

At the Ceremonial Opening of the Legal Year 2019, I emphasised the importance of making use of technology in providing legal services, citing the United Nations General Assembly in 2016 in observing that online dispute resolution "can assist the parties in resolving the dispute in a simple, fast, flexible, and secure manner, without the need for physical presence at a meeting or hearing". The Asia-Pacific Economic Cooperation had responded to the call and embarked on a project to establish an ODR framework with micro, small and medium-sized enterprises as major beneficiaries.

Almost 18% of the annual caseload of the courts at all levels have been affected in the first two months of the General Adjourned Period since January 29. The Judiciary has earlier started using video-conferencing facilities for remote hearings on suitable civil cases at the High Court. The media reported the first hearing conducted through video-conferencing, quoting the legal representatives of both parties being supportive of the Judiciary's new measures in view of the low cost and smooth operation.

Given the severe impact brought by COVID-19, the Judiciary has been exploring the use of various technological means in conducting different types of hearings to address the growing backlog of cases caused by the postponement of hearings. The legal sector should also take this opportunity to review the wider use of LawTech and enhance their technological capability. The Government introduced the LawTech Fund, which aims to assist some small and medium size law firms/barristers' chambers in procuring and upgrading information technology systems (such as video-conferencing facilities) and attending LawTech training courses. This will be conducive to the promotion of use of technologies in the provision of legal services.

Under the scheme, law firms and chambers with not more than five practicing lawyers are eligible for application. Each firm/chamber will be eligible for a reimbursable amount of up to $50,000. Application for the fund will be jointly administered by the Law Society of Hong Kong and the Hong Kong Bar Association. The details will be announced soon and the fund will be opened for application next month.

Other measures announced by the Government include: Enhancement of SME Financing Guarantee Scheme, Employment Support Scheme under which the Government will provide wage subsidy to eligible employers to retain employees (details will be available soon), as well as the creation of some time-limited jobs by the Department of Justice.

Government measures alone, however, would not be adequate. We must all stand united in solidarity to fight the virus and support Hong Kong.

Secretary for Justice Teresa Cheng wrote this article and posted it on her blog on April 11.

The Leisure & Cultural Services Department’s Community Oral History Theatre Project will be launched in Kowloon City District on January 15.

An oral history theatre performance and a sharing session will kick off the project.

The performance will feature an excerpt from the production of Sai Kung, Therefore I Live.

It will be held at Hung Hom Community Hall.

Admission is free with tickets.

Click here for details.

Guest of Honour at Film Mayo launch on 1st December

The Education Bureau today issued a circular memorandum to tutorial schools, inviting them to apply for a relief grant under the Anti-epidemic Fund.

The bureau said a total of about $120 million has been allocated from the fund to provide a one-off relief grant of $40,000 to each eligible tutorial school.

These tutorial schools must be registered under the Education Ordinance, have been operating in the three months before the class suspension - November, December and January - and be in operation on the application date.

Designated centres under the Financial Assistance Scheme for Designated Evening Adult Education Courses, which offer evening secondary school courses for adult learners, are also eligible for the grant.

The measure is expected to benefit about 3,000 tutorial schools, and the relief grant will be disbursed about four weeks upon receipt of an application.

Additionally, the fund will also provide relief grants to school-related service providers who have been affected by the prolonged class suspension, incurring an expenditure of about $419 million.

Beneficiaries will include operators of catering outlets at primary schools, secondary schools and post-secondary institutions and lunchbox providers of primary and secondary schools.

School bus drivers, school private light bus drivers and escorts, or nannies, as well as instructors, coaches, trainers and operators of interest classes engaged by schools, will also benefit from the relief grants.

The bureau will distribute application forms for the relief grant through post-secondary institutions to the catering outlets operating on their campuses within this week. The application details for other relief grants will be announced as soon as possible.

Separately, the bureau announced earlier that it would provide a one-off relief grant of $80,000 to each private school offering full and formal curriculum.

The grant has been disbursed progressively to schools under the English Schools Foundation, international schools, private independent schools, and other private secondary day schools and private primary schools.

John R. White
May 1, 2014; 27:82-86
From Research to Practice

Ryan A. Ristau
Nov 1, 2013; 26:211-215
From Research to Practice

Deborah Hinnen
Aug 1, 2017; 30:202-210
Feature Articles

Shani V. Davis
Aug 1, 2011; 24:148-153
Feature Article/Vitamin D in African Americans

(Arizona State University) Cun-Zheng Ning, a professor of electrical engineering in the Ira A. Fulton Schools of Engineering at Arizona State University, and collaborators from Tsinghua University in China discovered a process of physics that enables low-power nanolasers to be produced in 2D semiconductor materials. Understanding the physics behind lasers at nanoscale and how they interact with semiconductors can have major implications for high-speed communication channels for supercomputers and data centers.

We've all been saying it: These are unprecedented times. The impacts of the COVID-19 pandemic are incredibly wide-ranging and affect all facets of life. One that is hitting the scientific community very hard is the cancellation of meetings, large and small. While we are well-versed in connecting with colleagues and collaborators across a variety of online platforms, these do not replace the immensely gratifying aspects of attending meetings in person: the pleasure of catching up with old friends and making new ones, the insights gained from having real-time conversations with others working on the same topic but with different expertise and perspectives, and the stimulating new scientific ideas we carry home. We have all been feeling the disappointment as we learn that one meeting after another is forced to cancel, from the vibrant ASBMB annual meeting to summer conferences of all types.Another loss from the appropriate but painful decision to cancel the ASBMB annual meeting was the chance to hear from our Herbert Tabor Early Career Investigator Awardees, who represent the best science published in JBC in the preceding year. This year, the competition was particularly fierce. We hope and anticipate that we will be able to hear from the winners at next year's ASBMB annual meeting. But in the meantime, we want to raise a toast to Wenchao Zhao, Yue Yang, Manisha Dagar, Febin Varghese, and Ayumi Nagashima-Kasahara as our 2020 winners. We've captured their award-winning 2019 papers (1–5) on the JBC website (6), and extended profiles of the...

Previous studies have shown that sphingosine kinase interacting protein (SKIP) inhibits sphingosine kinase (SK) function in fibroblasts. SK phosphorylates sphingosine producing the potent signaling molecule sphingosine-1-phosphate (S1P). SKIP gene (SPHKAP) expression is silenced by hypermethylation of its promoter in acute myeloid leukemia (AML). However, why SKIP activity is silenced in primary AML cells is unclear. Here, we investigated the consequences of SKIP down-regulation in AML primary cells and the effects of SKIP re-expression in leukemic cell lines. Using targeted ultra-HPLC-tandem MS (UPLC-MS/MS), we measured sphingolipids (including S1P and ceramides) in AML and control cells. Primary AML cells had significantly lower SK activity and intracellular S1P concentrations than control cells, and SKIP-transfected leukemia cell lines exhibited increased SK activity. These findings show that SKIP re-expression enhances SK activity in leukemia cells. Furthermore, other bioactive sphingolipids such as ceramide were also down-regulated in primary AML cells. Of note, SKIP re-expression in leukemia cells increased ceramide levels 2-fold, inactivated the key signaling protein extracellular signal-regulated kinase, and increased apoptosis following serum deprivation or chemotherapy. These results indicate that SKIP down-regulation in AML reduces SK activity and ceramide levels, an effect that ultimately inhibits apoptosis in leukemia cells. The findings of our study contrast with previous results indicating that SKIP inhibits SK function in fibroblasts and therefore challenge the notion that SKIP always inhibits SK activity.

Prostate cancer (PCa) cells heavily rely on an active androgen receptor (AR) pathway for their survival. Enzalutamide (MDV3100) is a second-generation antiandrogenic drug that was approved by the Food and Drug Administration in 2012 to treat patients with castration-resistant prostate cancer (CRPC). However, emergence of resistance against this drug is inevitable, and it has been a major challenge to develop interventions that help manage enzalutamide-resistant CRPC. Erythropoietin-producing human hepatocellular (Eph) receptors are targeted by ephrin protein ligands and have a broad range of functions. Increasing evidence indicates that this signaling pathway plays an important role in tumorigenesis. Overexpression of EPH receptor B4 (EPHB4) has been observed in multiple types of cancer, being closely associated with proliferation, invasion, and metastasis of tumors. Here, using RNA-Seq analyses of clinical and preclinical samples, along with several biochemical and molecular methods, we report that enzalutamide-resistant PCa requires an active EPHB4 pathway that supports drug resistance of this tumor type. Using a small kinase inhibitor and RNAi-based gene silencing to disrupt EPHB4 activity, we found that these disruptions re-sensitize enzalutamide-resistant PCa to the drug both in vitro and in vivo. Mechanistically, we found that EPHB4 stimulates the AR by inducing proto-oncogene c-Myc (c-Myc) expression. Taken together, these results provide critical insight into the mechanism of enzalutamide resistance in PCa, potentially offering a therapeutic avenue for enhancing the efficacy of enzalutamide to better manage this common malignancy.

Haploinsufficiency of Meis homeobox 2 (MEIS2), encoding a transcriptional regulator, is associated with human cleft palate, and Meis2 inactivation leads to abnormal palate development in mice, implicating MEIS2 functions in palate development. However, its functional mechanisms remain unknown. Here we observed widespread MEIS2 expression in the developing palate in mice. Wnt1Cre-mediated Meis2 inactivation in cranial neural crest cells led to a secondary palate cleft. Importantly, about half of the Wnt1Cre;Meis2f/f mice exhibited a submucous cleft, providing a model for studying palatal bone formation and patterning. Consistent with complete absence of palatal bones, the results from integrative analyses of MEIS2 by ChIP sequencing, RNA-Seq, and an assay for transposase-accessible chromatin sequencing identified key osteogenic genes regulated directly by MEIS2, indicating that it plays a fundamental role in palatal osteogenesis. De novo motif analysis uncovered that the MEIS2-bound regions are highly enriched in binding motifs for several key osteogenic transcription factors, particularly short stature homeobox 2 (SHOX2). Comparative ChIP sequencing analyses revealed genome-wide co-occupancy of MEIS2 and SHOX2 in addition to their colocalization in the developing palate and physical interaction, suggesting that SHOX2 and MEIS2 functionally interact. However, although SHOX2 was required for proper palatal bone formation and was a direct downstream target of MEIS2, Shox2 overexpression failed to rescue the palatal bone defects in a Meis2-mutant background. These results, together with the fact that Meis2 expression is associated with high osteogenic potential and required for chromatin accessibility of osteogenic genes, support a vital function of MEIS2 in setting up a ground state for palatal osteogenesis.

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.

For successful infection of their hosts, pathogenic bacteria recognize host-derived signals that induce the expression of virulence factors in a spatiotemporal manner. The fulminating food-borne pathogen Vibrio vulnificus produces a cytolysin/hemolysin protein encoded by the vvhBA operon, which is a virulence factor preferentially expressed upon exposure to murine blood and macrophages. The Fe-S cluster containing transcriptional regulator IscR activates the vvhBA operon in response to nitrosative stress and iron starvation, during which the cellular IscR protein level increases. Here, electrophoretic mobility shift and DNase I protection assays revealed that IscR directly binds downstream of the vvhBA promoter PvvhBA, which is unusual for a positive regulator. We found that in addition to IscR, the transcriptional regulator HlyU activates vvhBA transcription by directly binding upstream of PvvhBA, whereas the histone-like nucleoid-structuring protein (H-NS) represses vvhBA by extensively binding to both downstream and upstream regions of its promoter. Of note, the binding sites of IscR and HlyU overlapped with those of H-NS. We further substantiated that IscR and HlyU outcompete H-NS for binding to the PvvhBA regulatory region, resulting in the release of H-NS repression and vvhBA induction. We conclude that concurrent antirepression by IscR and HlyU at regions both downstream and upstream of PvvhBA provides V. vulnificus with the means of integrating host-derived signal(s) such as nitrosative stress and iron starvation for precise regulation of vvhBA transcription, thereby enabling successful host infection.

The peroxisome is a subcellular organelle that functions in essential metabolic pathways, including biosynthesis of plasmalogens, fatty acid β-oxidation of very-long-chain fatty acids, and degradation of hydrogen peroxide. Peroxisome biogenesis disorders (PBDs) manifest as severe dysfunction in multiple organs, including the central nervous system (CNS), but the pathogenic mechanisms in PBDs are largely unknown. Because CNS integrity is coordinately established and maintained by neural cell interactions, we here investigated whether cell-cell communication is impaired and responsible for the neurological defects associated with PBDs. Results from a noncontact co-culture system consisting of primary hippocampal neurons with glial cells revealed that a peroxisome-deficient astrocytic cell line secretes increased levels of brain-derived neurotrophic factor (BDNF), resulting in axonal branching of the neurons. Of note, the BDNF expression in astrocytes was not affected by defects in plasmalogen biosynthesis and peroxisomal fatty acid β-oxidation in the astrocytes. Instead, we found that cytosolic reductive states caused by a mislocalized catalase in the peroxisome-deficient cells induce the elevation in BDNF secretion. Our results suggest that peroxisome deficiency dysregulates neuronal axogenesis by causing a cytosolic reductive state in astrocytes. We conclude that astrocytic peroxisomes regulate BDNF expression and thereby support neuronal integrity and function.

Inter-α-inhibitor is a proteoglycan essential for mammalian reproduction and also plays a less well-characterized role in inflammation. It comprises two homologous “heavy chains” (HC1 and HC2) covalently attached to chondroitin sulfate on the bikunin core protein. Before ovulation, HCs are transferred onto the polysaccharide hyaluronan (HA) to form covalent HC·HA complexes, thereby stabilizing an extracellular matrix around the oocyte required for fertilization. Additionally, such complexes form during inflammatory processes and mediate leukocyte adhesion in the synovial fluids of arthritis patients and protect against sepsis. Here using X-ray crystallography, we show that human HC1 has a structure similar to integrin β-chains, with a von Willebrand factor A domain containing a functional metal ion-dependent adhesion site (MIDAS) and an associated hybrid domain. A comparison of the WT protein and a variant with an impaired MIDAS (but otherwise structurally identical) by small-angle X-ray scattering and analytical ultracentrifugation revealed that HC1 self-associates in a cation-dependent manner, providing a mechanism for HC·HA cross-linking and matrix stabilization. Surprisingly, unlike integrins, HC1 interacted with RGD-containing ligands, such as fibronectin, vitronectin, and the latency-associated peptides of transforming growth factor β, in a MIDAS/cation-independent manner. However, HC1 utilizes its MIDAS motif to bind to and inhibit the cleavage of complement C3, and small-angle X-ray scattering–based modeling indicates that this occurs through the inhibition of the alternative pathway C3 convertase. These findings provide detailed structural and functional insights into HC1 as a regulator of innate immunity and further elucidate the role of HC·HA complexes in inflammation and ovulation.

Heme-regulatory motifs (HRMs) are present in many proteins that are involved in diverse biological functions. The C-terminal tail region of human heme oxygenase-2 (HO2) contains two HRMs whose cysteine residues form a disulfide bond; when reduced, these cysteines are available to bind Fe3+-heme. Heme binding to the HRMs occurs independently of the HO2 catalytic active site in the core of the protein, where heme binds with high affinity and is degraded to biliverdin. Here, we describe the reversible, protein-mediated transfer of heme between the HRMs and the HO2 core. Using hydrogen-deuterium exchange (HDX)-MS to monitor the dynamics of HO2 with and without Fe3+-heme bound to the HRMs and to the core, we detected conformational changes in the catalytic core only in one state of the catalytic cycle—when Fe3+-heme is bound to the HRMs and the core is in the apo state. These conformational changes were consistent with transfer of heme between binding sites. Indeed, we observed that HRM-bound Fe3+-heme is transferred to the apo-core either upon independent expression of the core and of a construct spanning the HRM-containing tail or after a single turnover of heme at the core. Moreover, we observed transfer of heme from the core to the HRMs and equilibration of heme between the core and HRMs. We therefore propose an Fe3+-heme transfer model in which HRM-bound heme is readily transferred to the catalytic site for degradation to facilitate turnover but can also equilibrate between the sites to maintain heme homeostasis.