Self-generated quantum gauge fields in arrays of Rydberg atoms

As shown in recent experiments [V. Lienhard et al., Phys. Rev. X 10, 021031 (2020)], spin-orbit coupling in systems of Rydberg atoms can give rise to density-dependent Peierls Phases in second-order hoppings of Rydberg spin excitations and nearest-neighbor (NN) repulsion. We here study theoretically a one-dimensional zig-zag ladder system of such spin-orbit coupled Rydberg atoms at half filling. The second-order hopping is shown to be associated with an effective gauge field, which in mean-field approximation is static and homogeneous. Beyond the mean-field level the gauge potential attains a transverse quantum component whose amplitude is dynamical and linked to density modulations. We here study the effects of this to the possible ground-state phases of the system. In a phase where strong repulsion leads to a density wave, we find that as a consequence of the induced quantum gauge field a regular pattern of current vortices is formed. However also in the absence of density-density interactions the quantum gauge field attains a non-vanishing amplitude. Above a certain critical strength of the second-order hopping the energy gain due to gauge-field induced transport overcomes the energy cost from the associated build-up of density modulations leading to a spontaneous generation of the quantum gauge field.

BRCA1 deficiency specific base substitution mutagenesis is dependent on translesion synthesis and regulated by 53BP1

Defects in BRCA1, BRCA2 and other genes of the homology-dependent DNA repair (HR) pathway cause an elevated rate of mutagenesis, eliciting specific mutation patterns including COSMIC signature SBS3. Using genome sequencing of knock-out cell lines we show that Y family translesion synthesis (TLS) polymerases contribute to the spontaneous generation of base substitution and short insertion/deletion mutations in BRCA1 deficient cells, and that TLS on DNA adducts is increased in BRCA1 and BRCA2 mutants. The inactivation of 53BP1 in BRCA1 mutant cells markedly reduces TLS-specific mutagenesis, and rescues the deficiency of template switch–mediated gene conversions in the immunoglobulin V locus of BRCA1 mutant chicken DT40 cells. 53BP1 also promotes TLS in human cellular extracts in vitro. Our results show that HR deficiency–specific mutagenesis is largely caused by TLS, and suggest a function for 53BP1 in regulating the choice between TLS and error-free template switching in replicative DNA damage bypass.

Enhanced Spontaneous Antibacterial Activity of δ-MnO2 by Alkali Metals Doping

Recently, the widespread use of antibiotics is becoming a serious worldwide public health challenge, which causes antimicrobial resistance and the occurrence of superbugs. In this context, MnO2 has been proposed as an alternative approach to achieve target antibacterial properties on Streptococcus mutans (S. mutans). This requires a further understanding on how to control and optimize antibacterial properties in these systems. We address this challenge by synthesizing δ-MnO2 nanoflowers doped by magnesium (Mg), sodium (Na), and potassium (K) ions, thus displaying different bandgaps, to evaluate the effect of doping on the bacterial viability of S. mutans. All these samples demonstrated antibacterial activity from the spontaneous generation of reactive oxygen species (ROS) without external illumination, where doped MnO2 can provide free electrons to induce the production of ROS, resulting in the antibacterial activity. Furthermore, it was observed that δ-MnO2 with narrower bandgap displayed a superior ability to inhibit bacteria. The enhancement is mainly attributed to the higher doping levels, which provided more free electrons to generate ROS for antibacterial effects. Moreover, we found that δ-MnO2 was attractive for in vivo applications, because it could nearly be degraded into Mn ions completely following the gradual addition of vitamin C. We believe that our results may provide meaningful insights for the design of inorganic antibacterial nanomaterials.

TB-3 miR-33a depletion accelerate medulloblastoma generation and invasion

Background and purposes: Lipid metabolism have been shown to be associated with tumorigenicity in various malignancies. The purpose of this study was to investigate the association of miR-33, a key regulator of lipid metabolism, in tumorigenicity and progression of medulloblastoma. Methods: Incidence of medulloblastoma and histopathological findings were compared between ptch1+/- mice and ptch1+/- miR-33a-/- mice. Tumors extracted from these mice were transplanted subcutaneously in nude mice (n=14 for ptch1+/-, n=19 for ptch1+/- miR-33a-/-) and in C57BL/6 mice (n=12 for each). Gene expression profile was compared between tumors from ptch1+/- mice and those from ptch1+/- miR-33a-/- mice. Results: Knockout of miR-33a in ptch1+/- transgenic mouse model increased the incidence of spontaneous generation of medulloblastoma from 34.5% to 84.0% (p< 0.001) at 12 months. Histopathological analysis showed infiltrative tumor borders in ptch1+/- miR-33a-/- tumors as compared with ptch1+/- ones. Tumor formation was observed in 21.4% for ptch1+/- tumors and 68.4% for ptch1+/- miR-33a-/- tumors in nude mice (p= 0.008). It was observed in 0% and 16.7% in immune competent mice. RNA sequencing detected that SCD1 and SREBF1 was upregulated in tumors from miR-33a knockout mice. Discussion: Our results demonstrated that depletion of miR-33a accelerated medulloblastoma generation and invasion. miR-33a may also be important for immune evasion. SCD1, which is reported to play a role in tumor stem cell maintenance and metastasis, can be a potential therapeutic target for medulloblastoma.

From the History of the Infection Study

The article reflects the development of ideas about infection, from the ancient period to the present day. In the V century Hippocrates proposed a miasmatic theory, according to which diseases are caused by harmful fumes. This paradigm remained dominant for 2.5 millennia. Although the existence of microorganisms has been known since 1676, when they were first described by Anthony van Leeuwenhoek, for a long time the detection of microbes in the biosubstrates of a sick person was considered as a secondary phenomenon in relation to the disease. The theoretical basis for such ideas was the concept of spontaneous generation, which has dominated since the time of Aristotle. The change from the miasmatic theory to the infectious paradigm was due to the fundamental discoveries of Louis Pasteur, who proved the biological nature of fermentation and the infectious genesis of silkworm diseases. The listed discoveries put an end to the discussion about spontaneous generation, became the scientific justification for asepsis and antiseptics and aimed at searching for pathogens of infectious human diseases, which led to a surge in discoveries in microbiology. The causative agents of fever (1868), leprosy (1873), anthrax (1876), tuberculosis (1882), cholera (1883), diphtheria (1884), plague (1894), etc. were discovered. As a result, the infectious theory finally conquered the world. An important achievement of the late 19th century was the allocation of a new type of infectious agents — viruses, which make up the most numerous form of life. With the recognition of the infectious theory at the end of the 19th century an active search for antimicrobial agents began. In 1943, the mass production of the first antibiotic, penicillin, was launched, the discovery of which is called one of the most outstanding achievements in the history of mankind. The use of antimicrobial drugs, along with mass vaccination, led to a significant decrease in the share of infectious diseases in the structure of mortality.

Calculation of the contribution to muon g − 2 due to the effective anomalous three boson interaction and the new experimental result

Using the approach based on Bogoliubov compensation principle is applied to the calculation of a contribution to the muon [Formula: see text]. Using the previous results on spontaneous generation of the effective anomalous three-boson interaction we calculate the contribution, which proves to agree with the well-known discrepancy. The calculated quantity contains no adjusting parameters but the experimental values for the muon and the [Formula: see text]-boson masses. The result can be considered as a confirmation of the approach.

$$A_0$$-condensation in quark-gluon plasma with finite baryon density

In the present paper, we return to the problem of spontaneous generation of the $$A_0$$ A 0 -background field in QCD at finite temperature and a quark chemical potential, $$\mu $$ μ . On the lattice, this problem was studied by different approaches where an analytic continuation to the imaginary potential $$i \mu $$ i μ has been used. Here we consider both, real and imaginary chemical potential, analytically within the two-loop gauge-fixing independent effective potential $$W_{eff.}$$ W e f f . . We realize the gauge independence in to ways: (1) on the base of Nielsen’s identity and (2) expressing the potential in terms of Polyakov’s loop. Firstly we reproduce the known expressions in terms of Bernoulli’s polynomials for the gluons and quarks. Then, we calculate the $$\mu $$ μ -dependence, either for small $$\mu $$ μ as expansion or numerically for finite $$\mu $$ μ , real and imaginary. One result is that the chemical potential only weakly changes the values of the condensate fields, but quite strongly deepens the minima of the effective potential. We investigate the dependence of Polyakov’s loop in the minimum of the effective potential, thermodynamic pressure and Debye’s mass on the chemical potential. Comparisons with other results are given.

Matter as an Artist: Rubens’s Myths of Spontaneous Generation

Three works by Peter Paul Rubens (1577–1640) entail mythologized scenes of spontaneous generation, or the creation of species from nature’s raw matter: Head of Medusa (ca. 1613–1618), The Discovery of Erichthonius (ca. 1616), and the oil sketch Deucalion and Pyrrha (ca. 1636). In these works Rubens naturalizes the life of painting within its materials, implying matter—paint, with its pigments and mediating liquids—as an intrinsic, animating quality of his images and even as a counterpart to or collaborator with the artist. This essay explores these ideas to show how Rubens’s technical and artisanal understanding of painting and its materials could have informed his interpretation of ancient myths.

Spontaneous generation of diversity in Arachis neopolyploids (A. ipaënsis x A. duranensis)4x replays the early stages of peanut evolution

Polyploidy is considered a driving force in plant evolution and domestication. Although in the genus Arachis, several diploid species were traditionally cultivated for their seeds, only the allotetraploid peanut Arachis hypogaea became the successful, widely spread legume crop. This suggests that polyploidy has given selective advantage for domestication of peanut. Here we study induced allotetraploid (neopolyploid) lineages obtained from crosses between the peanut’s progenitor species, A. ipaënsis and A. duranensis, at earlier and later generations. We observed plant morphology, seed dimensions, and genome structure using cytogenetics (FISH and GISH) and SNP genotyping. The neopolyploid lineages show more variable fertility and seed morphology than their progenitors and cultivated peanut. They also showed sexual and somatic genome instability, evidenced by changes of number of detectable 45S rDNA sites, and extensive homoeologous recombination indicated by mosaic patterns of chromosomes and changes in dosage of SNP alleles derived from the diploid species. Genome instability was not randomly distributed across the genome: the more syntenic chromosomes, the higher homoeologous recombination. Instability levels are higher than observed on peanut lines, therefore it is likely that more unstable lines tend to perish. We conclude that early stages of the origin and domestication of the allotetraploid peanut involved two genetic bottlenecks: the first, common to most allotetraploids, is composed of the rare hybridization and polyploidization events, followed by sexual reproductive isolation from its wild diploid relatives. Here we suggest a second bottleneck: the survival of the only very few lineages that had stronger mechanisms for limiting genomic instability.

World Soul

The concept of the world soul is difficult to understand in large part because over the course of history it has been invoked to very different ends and within the frameworks of very different philosophical systems, with very different concepts of the world soul emerging as a result. This volume brings together eleven chapters by leading philosophers in their respective fields that collectively explore the various ways in which this concept has been understood and employed, covering the following philosophical areas: Platonism, Stoicism, Medieval, Indian (Vedāntic), Kabbalah, Renaissance, Early Modern, German Romanticism, German Idealism, American Transcendentalism, and contemporary quantum mechanics and panpsychism theories. In addition, short reflections illuminate the impact the concept of the world soul has had on a small selection of areas outside of philosophy: harmony, biology (spontaneous generation), the music of Henry Purcell, psychoanalysis, and Gaia theories.