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Systemic lupus erythematosus (SLE) is a complex autoimmune condition that disproportionately impacts non-White ethnic and racial groups, particularly individuals in the African diaspora who experience heightened incidence, prevalence, and adverse outcomes. Genetic and epigenetic factors play significant roles in SLE risk, however these factors neither explain the whole of SLE risk nor the stark racial disparities we observe. Moreover, our understanding of genetic risk factors within African ancestry populations is limited due to social and environmental influences on research participation, disease presentation, and healthcare access. Globally, the African diaspora faces barriers in accessing essential SLE diagnostic tools, therapeutics, healthcare practitioners, and high-quality clinical and translational research studies. Here, we provide insights into the current state of genetic studies within African ancestry populations and highlight the unique challenges encountered in SLE care and research across countries of varying income levels. We also identify opportunities to address these disparities and promote scientific equity for individuals affected by SLE within the global African diaspora. [ABSTRACT FROM AUTHOR]

Does Kim Jong Un need nuclear weapons to deter the United States? Pyongyang has long insisted that nuclear weapons prevent the United States from invading North Korea. But, do nuclear weapons provide Pyongyang with as much deterrent effect as it expects? Has the conventional military posture failed in deterring the U.S.-ROK alliance? This article challenges conventional wisdom on North Korean nuclear deterrence and raises the question of why nuclear weapons do not help Pyongyang improve its deterrence capability. Pyongyang's pursuit of nuclear deterrence is an overdeterrence. Pyongyang's presumably assured retaliation is not credible given the United States' superb nuclear capability. Rather, conventional deterrence has worked on the Korean peninsula. Pyongyang may have other reasons to build up its nuclear capability, but the risks and costs are too high to take. This article also suggests highly important and timely theoretical and policy implications about how to deal with a nuclear North Korea. [ABSTRACT FROM AUTHOR]

Toxin–antitoxin (TA) systems, which consist of an intracellular toxin and its antidote (antitoxin), are encoded by ubiquitous genetic modules in prokaryotes. Commonly, the activity of a toxin is inhibited by its antitoxin under normal growth conditions. However, antitoxins are degraded in response to environmental stress, and toxins liberated from antitoxins consequently induce cell death or growth arrest. In free-living prokaryotes, TA systems are often present in large numbers and are considered to be associated with the adaptation of pathogenic bacteria or extremophiles to various unfavorable environments by shifting cells to a slow growth rate. Genomic analysis of the human pathogen Mycobacterium tuberculosis H37Rv (Mtb) revealed the presence of a large number of TA systems. Accordingly, we investigated five uncharacterized TA systems (Rv2019-Rv2018, Rv3697c-Rv3697A, Rv3180c-Rv3181c, Rv0299-Rv0298, and Rv3749c-Rv3750c) of Mtb. Among these, the expression of the Rv2019 toxin inhibited the growth of Escherichia coli, and M. smegmatis and this growth defect was recovered by the expression of the Rv2018 antitoxin. Interestingly, Rv3180c was toxic only in M. smegmatis, whose toxicity was neutralized by Rv3181c antitoxin. In vivo and in vitro assays revealed the ribosomal RNA (rRNA) cleavage activity of the Rv2019 toxin. Moreover, mRNAs appeared to be substrates of Rv2019. Therefore, we concluded that the ribonuclease activity of the Rv2019 toxin triggers the growth defect in E. coli and that the Rv2018 antitoxin inhibits the ribonuclease activity of the Rv2019 toxin. [ABSTRACT FROM AUTHOR]

The metal-reducing bacterium Geobacter sulfurreducens requires the expression of conductive pili to reduce iron oxides and to wire electroactive biofilms, but the role of pilus retraction in these functions has remained elusive. Here we show that of the four PilT proteins encoded in the genome of G. sulfurreducens, PilT3 powered pilus retraction in planktonic cells of a PilT-deficient strain of P. aeruginosa and restored the dense mutant biofilms to wild-type levels. Furthermore, PilT3 and PilT4 rescued the twitching motility defect of the PilT-deficient mutant. However, PilT4 was the only paralog whose inactivation in G. sulfurreducens lead to phenotypes associated with the hyperpiliation of non-retractile mutants such as enhanced adhesion and biofilm-forming abilities. In addition, PilT4 was required to reduce iron oxides. Taken together, the results indicate that PilT4 is the motor ATPase of G. sulfurreducens pili and reveal a previously unrecognized role for pilus retraction in extracellular electron transfer, a strategy that confers on Geobacter spp. an adaptive advantage for metal reduction in the natural environment. [ABSTRACT FROM AUTHOR]

Successive South Korean governments have made every effort to build the foundation for the peaceful unification of the Korean Peninsula. The Park Geun-hye administration has also emphasized the importance of laying the foundation for peaceful unification and presented it as one of four administrative priorities. However, regardless of which administration assumes office, a state-centric approach has been taken towards the issue of unification. Whoever governs in South Korea, unification diplomacy targeting the four great powers has been their foremost priority. Such a state-centric approach may perhaps be an inevitable strategy to achieve Korean unification, particularly given the history of the division of the two Koreas and international relations around the Korean Peninsula. German unification in 1990 was made possible due to the interaction and cooperation among neighboring powers in the process of the Cold War's collapse. Therefore the roles and influences of the four great powers in the process of Korean unification cannot be understated. However, Korean unification has not yet been realized despite many efforts through the state-centric approach. On the contrary, it is debatable whether the state-centric approach focusing on the great powers has made unification rather difficult due to the serious conflicts of interest among those powers regarding Korean unification. This is the paradox of unification diplomacy in building the foundation for peaceful unification on the Korean Peninsula. In this context, it becomes necessary to recognize the weaknesses of a state-centric approach in the case of Korean unification and to search for new possibilities that nonstate actors can provide. [ABSTRACT FROM AUTHOR]

CspA is a major cold shock-inducible protein (70 aa), and its major role in the cold shock response was shown to be as an RNA chaperone destabilizing secondary structure of mRNAs at low temperature. Previously, we showed that the overexpression of mutant cspA containing premature non-sense codons at various positions led to stalled ribosomes on mutant cspA transcripts, ultimately leading to cell death. This lethality is primarily due to the highly translatable cspA 5'- UTR that recruits most of the ribosomes from other mRNAs, which are then stalled at the abnormal stop codon. This was called the `LACE' effect. We show here that non-sense mutation even at the 67th position as well as substitutions of aromatic amino acid residues present on the RNA-binding surface of CspA protein to alanine caused the LACE effect by trapping a substantial amount of ribosomes on cspA mRNA5. In an attempt to identify a suppressor(s), which may help the cells to recover from the inhibitory LACE effect, genetic screening of an Escherichia coli genomic library was performed. We isolated suppressors that contained the genomic fragments encoding uvrD and dinG, respectively, whose gene products are ATP-dependent DNA helicases. The nucleic acid-binding and ATPase activities of these two helicases were found to be essential for their suppression activity. This genomic screening offers an approach to shed light on the mechanistic of 5'-UTR of cspA mRNA and novel roles of E. coli helicases that function in DNA repair. [ABSTRACT FROM AUTHOR]

In this work, PZT (52/48) and PZT (30/70) thin films were deposited at a substrate temperature of 600°C with Argon gas pressure ranging from 2.8 × 10-2 mbar to 4.3 × 10-3 mbar by r. f. magnetron sputtering on LNO/Si substrates. Highly (100)-oriented rhombohedral structured PZT (52/48) thin films were formed. We found that the out-of-plane lattice constant increased commensurately with a decrease in Ar pressure, while remnant polarization and dielectric constant increased with decreasing Ar pressure. On the other hand, the PZT (30/70) thin films sputter-deposited on LNO/Si(100) at substrate temperatures of 600°C with various Ar gas pressures formed a tetragonal structure. The fraction of c-domain, hence the remnant polarization, increased with decreasing Ar pressure, while the dielectric constant decreased with decreasing Ar pressure. [ABSTRACT FROM AUTHOR]

In this work, PZT (52/48) thin films were deposited at substrate temperature ranging from room temperature (RT) to 600°C and with various oxygen percentage in a mixed argon and oxygen gas at substrate temperature of 600°C on LNO/Si by an r.f. magnetron sputtering method. It was found that the crystallinities were enhanced with increasing substrate temperature. Hence, the ferroelectricities and electrical properties were also simultaneously improved. The crystallinities degraded with increasing O2 percentages, hence, the degraded ferroelectricities and relevant electrical properties. [ABSTRACT FROM AUTHOR]