Search Results (292)

Background/Objectives: Among the many proposed theories of aging, a growing body of research points to epigenetic alterations, particularly changes in DNA methylation patterns, as key contributors to biological decline. DNA methylation can be targeted and modulated to induce anti-aging and regenerative effects using an emerging therapeutic approach known as partial reprogramming, induced by different combinations of Yamanaka factors. Methods: In this study, we performed an integrative secondary analysis of five publicly available DNA methylation datasets derived from partial reprogramming experiments across multiple mammalian species, tissues, cell types and combinations of transcription factors (n = 189 samples). Results: Following differential methylation analysis of 929,009 CpGs, we identified 14 CpG sites showing reproducible and significant changes, with two CpGs consistently present across all datasets. Conclusions: These findings suggest that partial reprogramming may exert anti-aging and regenerative effects, in part, through the selective modulation of conserved DNA methylation sites. Full article

A comprehensive beyond density functional theory study of the structural, energetic, and electronic properties of the technologically most relevant SiC polytypes 3C, 2H, 4H, and 6H-SiC, together with the single Shockley-type stacking fault (1SSF or 31SSF) in 4H-SiC, was conducted. Lattice constants computed at the PBEsol and HSE06 level match experimental values within 0.1% accuracy. Total energies evaluated at the random-phase approximation level yield a physically consistent hierarchy of polytypes with 3C-SiC as the most stable phase, which is in agreement with low-temperature experimental results. Quasiparticle band gaps computed with both the single-shot G0W0@PBE and the partially self-consistent GW0@PBE formulations quantitatively match well with the experimental values. The band structure of 31SSF reveals fault-induced sub-gap band splitting at the M point of 0.21 eV at the GGA level, which increases to 0.28 eV upon G0W0 correction. To our knowledge, this provides the first GW-level treatment of the 31SSF electronic structure in 4H-SiC. These results collectively provide a many-body perturbation theory (MBPT) level reference dataset for SiC polytypes and the commonly found stacking fault in 4H-SiC. Full article

In this study, the Boscovich curve of 1763 is reinterpreted as a mean-field potential for interacting particles in condensed matter. In a dense many-body system, each particle experiences an effective potential arising from the average distribution of all the others. This mean-field potential, which exhibits alternating maxima (energy barriers) and minima (coordination shells), thereby reducing the complexity of the N-body problem to an effective two-body radial problem, with the correlation distance r as the key variable. The relationship between the PMF and the radial distribution function g(r) is given by the Kirkwood equation U_B(r) = −kT ln g(r), which provides a multi-well potential in condensed matter. Furthermore, the system is described by the Fisher density functional equation for the correlation amplitudes, −2kT ∇²ψ(r) + U_B(r)ψ(r) = μψ(r) whose eigenvalues μ_i correspond to potential levels and whose eigenfunctions ψ_i are the correlation amplitudes of the coordination shell structure. Based on the multi-well potential picture, the oscillatory behavior of U_B(r) is modeled analytically by a weighted sum of Lennard-Jones potentials, modulated by sigmoid functions. The parameters—well depths, widths, and coordination distances—are assigned on the basis of known structural properties of the system, derived either from experimental data or from geometric models such as FCC or HCP lattices. The radial distribution function is then reconstructed as a linear combination of the squared eigenfunctions obtained from the Fisher equation. The resulting discrete eigenvalue spectrum provides a spectral interpretation of the shell structure of condensed matter, wherein the complexity of many-body interactions is encoded in a hierarchy of correlation modes, each associated with a specific coordination shell. Unlike classical DFT—which relies on approximate excess free-energy functionals—and Ornstein–Zernike theory—which requires closure approximations—our approach provides a direct spectral interpretation of the coordination shell structure through the eigenvalue spectrum of the Fisher equation, where the PMF acts as the effective potential and the radial distribution function is reconstructed as a combination of squared eigenfunctions. The method is validated for liquid argon and FCC lattices and establishes a historical connection with Boscovich’s curve as a statistical potential. Full article

It is becoming harder to feel at home. As wildfires, floods, drought, and heat become recurrent rather than exceptional, and as everyday life fills with weather alerts, evacuation warnings, and preparedness drills, many people experience a particular kind of distress: the pain of remaining in a place that is still physically present but no longer feels safe, familiar, or trustworthy. This paper examines that experience through the concept of solastalgia—homesickness felt while still at home—and argues that it is not a private mood or a distortion of thinking, but a meaningful disturbance in the very conditions of dwelling. Bringing together phenomenology, emotional geography, and emotion-regulation theory, it shows how a pervasive “culture of emergency” reshapes the way we inhabit space, time, our bodies, and our relationships with others, narrowing the room we feel we have to live and act. Rather than treating climate-related anxiety as something to be corrected, the paper understands it as an honest response to a world whose stability has genuinely been compromised. It then asks how home might become livable again, arguing that repair must happen at several levels at once—personal, communal, and institutional—and that a workable sense of belonging can be rebuilt without denying what has been lost. Full article

In complex systems theory, there are different ways to describe a system in terms of information, such as emergence (Shannon entropy), self-organization, and complexity. These measures provide information about the dynamic behavior of a complex system. We study the differences in entropy and complexity for many-body systems undergoing a transition from a regular to a chaotic regime. To do this, we analyze the eigenvectors of the ⁴⁸Ca nucleus for different quadrupole-type two-body interactions. We obtain the eigenvectors by diagonalizing the two-body Hamiltonian for ⁴⁸Ca using the ANTOINE code. We then calculate the entropy and complexity for the different quadrupole-type interactions. The differences found in information entropy and complexity are clear when comparing a regular system with a chaotic one. We find that the complexity of the regular and chaotic states of ⁴⁸Ca shows differences associated with its internal interactions. Full article

In both nature and engineering, there are many structures similar to spherical cacti with ribs. In this study, we investigated numerically the laminar natural convection heat transfer characteristics of spherical cactus-like bodies. An analytical framework was established based on constructal theory, and the maximum temperature as well as the temperature distribution factor were obtained via numerical simulations. The results show that for a fixed total volume and rib volume ratio (ω = 17%), there exists an optimal rib number n_opt = 34 at which the maximum temperature T_max reaches its minimum value of 58.97 °C, 5.45 °C lower than that of the smooth sphere. The body with a lower maximum temperature also features a larger low-temperature region. Under specified conditions, as the Rayleigh number increases from 10⁵ to 10⁷, n_opt increases from 24 to 42; as the thermal conductivity increases from 0.12 to 3 W/(m·K), n_opt rises from 24 to 36; conversely, a larger rib volume ratio (ω = 30%) reduces n_opt accordingly. Compared with the single-scale rib structure, the adoption of a two-scale rib design or ellipsoidal designs further improves the heat transfer performance, with the temperature distribution factor indicating a larger low-temperature region. The results of this study can provide a reference for the thermal design of cactus-like engineering devices and offer a heat transfer perspective for understanding the heat dissipation mechanism of cactus-type plants in nature. Full article

Propagation anisotropy in one-dimensional conductors is commonly interpreted within the framework of Tomonaga–Luttinger liquid theory, where electron–electron interactions lead to distinct channel-dependent excitation velocities. In this work, we investigate a complementary mechanism in which propagation anisotropy arises from structured substrate modulation. We develop a quantitative two-channel effective-medium transport model incorporating position-dependent dielectric and magnetic coupling terms within an effective spinor Hamiltonian. Under an adiabatic envelope approximation, the coupled spinor dynamics are reduced to an effective scalar propagation equation suitable for numerical simulation. The model predicts that spatial modulation of substrate response can generate measurable channel-dependent velocity splitting, wave-packet deformation, and propagation delay. Numerical simulations show that dielectric modulation, magnetic modulation, relative phase shifts, and moderate disorder influence transport anisotropy in distinct and tunable ways. For experimentally realistic parameter ranges, the predicted propagation delay lies in the picosecond regime over micrometer-scale transport distances. Comparison with conventional Tomonaga–Luttinger liquid theory suggests that substrate-induced effects may coexist with intrinsic many-body interactions and contribute appreciably to observed transport behavior. The proposed framework provides a quantitative phenomenological tool for analyzing substrate-controlled anisotropic transport and offers experimentally testable predictions for low-dimensional quantum systems. Full article

Two-dimensional (2D) group-IV materials are promising for spintronics due to their silicon compatibility and tunable properties. In this work, we investigate the structural, electronic, magnetic, and optical properties of semi-hydrogenated 2D SiGe random alloys—where hydrogen atoms saturate only one side of the atomic plane—using density functional theory and many-body perturbation theory ($G{W}_0$). Substitutional disorder is modeled via representative high-symmetry configurations introduced by Baldereschi and co-workers to enable quasiparticle and optical simulations in large supercells. We demonstrate that these semi-hydrogenated alloys possess an intrinsic magnetic semiconducting ground state, arising from the electronic structure of the system, with an integer magnetic moment of $1{\mathsf{\mu }}_{\mathrm{B}}$ per primitive cell. The spin-resolved electronic structure features nearly flat frontier bands and a finite energy gap, which is significantly renormalized by quasiparticle corrections while maintaining robust spin polarization. These properties remain remarkably stable across different realizations of chemical disorder and over a wide range of alloy compositions considered in this work. Optical spectra calculated within the random phase approximation reveal a composition-dependent red-shift of the low-energy onset in the imaginary part of the dielectric function, consistent with the evolution of the quasiparticle electronic structure and the persistence of flat spin-polarized frontier bands. Our findings establish semi-hydrogenated 2D SiGe random alloys as a resilient model platform to explore interaction-driven magnetism in disordered two-dimensional systems, while simultaneously offering realistic prospects for spintronic and magneto-optoelectronic applications in the presence of chemical disorder. Full article

Chromic materials exhibiting reversible changes in optical properties under external stimuli represent an important class of smart materials with applications in smart windows, sensors, and optoelectronic devices. Transition-metal oxides (TMOs) provide a versatile platform for chromic functionality due to their coupled structural, electronic, and optical properties. In this review, the chromic response of selected TMO thin films is analyzed using both microscopic and phenomenological approaches. The microscopic description is based on many-body theory, including Green’s function methods and correlation effects, while the macroscopic optical response is described using Drude–Lorentz and Tauc–Lorentz models within the effective medium approximation. Chromic behavior in TMOs is shown to originate from two principal mechanisms: (i) electronic and structural reconstruction driven by Peierls–Mott metal–insulator phase transitions, leading to thermochromism (notably in VO₂ and V₂O₃), and (ii) formation of localized states driven by small-polaron injection, giving rise to electrochromism, gasochromism, and photochromism. The models are applied to representative systems, including VO₂, WO₃, NiO, and TiO₂, demonstrating the chromic changes in the dielectric function spectra. These results highlight chromism in TMOs as a multiscale phenomenon linking microscopic interactions with macroscopic optical response. Full article

A developed method, based on the stationary second-order Rayleigh–Schrödinger many-body perturbation theory in an irreducible tensorial form, allows us to determine the most important core–valence, core, core–core, and valence–valence correlations for any atom or ion with an arbitrary number of valence and core electrons. This paper presents the Feynman diagrams that describe these correlations. Additionally, it provides the rules for obtaining algebraic expressions in an irreducible tensorial form for any Feynman diagram coming from second-order many-body perturbation theory. Whereas some types of the valence–valence and core–valence correlations are described by the three-particle Feynman diagrams, additional developments to calculate the spin-angular parts of these diagrams have been made to the program library librang of the Grasp2018 As an example of the application of the developed method, the atomic calculations of the energy level structure and transition data for Ar II are presented. Full article

A realistic description of halo nuclei, characterized by low-lying breakup thresholds, requires a proper treatment of continuum effects. We have developed an ab initio approach, the No-Core Shell Model with Continuum (NCSMC), capable of describing both bound and unbound states in light nuclei in a unified way. With chiral two- and three-nucleon interactions as the only input, we can predict the structure and dynamics of halo and other light nuclei and, by comparing to available experimental data, test the quality of chiral nuclear forces. We review NCSMC calculations of weakly bound states and resonances of the exotic halo nuclei ⁶He, ⁸B, ¹¹Be, and ¹⁵C. For the latter, we discuss its production in the capture reaction ¹⁴C(n,$\gamma$)¹⁵C. We highlight the challenges of a description of ⁶He as a Borromean n-n-⁴He system. Finally, we present our calculations of excited states in ¹⁰Be exhibiting a one-neutron halo structure and a large scale No-Core Shell Model investigation of ¹¹Li as a precursor of a full n-n-⁹Li NCSMC study. Full article

Nuclei are complex many-body quantum systems where interactions of the neutrons and protons via the strong, the weak, and the electromagnetic forces lead to the emergence of simple patterns of energy states that have been described by various theoretical approaches. One of the goals of all the theoretical models is the development of a universal theory that can be applied across the entire chart of nuclides. Significant progress has been made by experiments as well as the increasing sophistication of models, but a universal theory has yet to be established. A recent reviewof nuclei in the Z = 50–82 region of the chart of nuclides has analyzed all the available compiled data from several decades of studies towards a clarification of the low-lying structure of nuclei. Other reviews have reported and explained the emergence of multiple different shapes in nuclei at somewhat higher excitation energies than the ground state. Somehave challenged the interpretation of the first excited K^π $=0^{+}$ band as a vibration of ground state. This work attempts to provide a guide to determining the nature of the first excited K^π $=0^{+}$ band in nuclei by the combined use of nuclear lifetimes, energy level evolutions, dynamic moments of inertia, and intrinsic quadrupole moments extracted from transition probabilities. The result is that for a subset of the nuclei in this region, the K^π $=0^{+}$ band is consistent with the traditional $\beta$-vibration description of an oscillation built on the ground state. Full article

In this paper, we review the physics of many bodies in the context of general relativity. Starting from the stress–energy tensor for one body and moving onto those for a swarm of bodies and for a perfect fluid, we review the relativistic hydrodynamics, kinetic theory, and statistical physics of N identical bodies. We conclude our excursion with a thermal equivalence principle in physics. Full article

Fatphobia, or the stigmatization of fat bodies, is increasingly prevalent in our society and is manifested in many ways, leading to serious consequences for those who suffer its effects. This study aims to enhance the understanding of the extent of media coverage regarding this issue, as well as the approach taken in its coverage. To this end, all the information containing the term fatphobia, which was published in six leading Spanish-language newspapers, (n = 309) was analyzed to pinpoint the moment when fatphobia appeared on the media agenda, as well as the specific features of its coverage. Using a multidisciplinary methodology including content analysis, framing theory, and a gender perspective, the following digital media outlets were analyzed: eluniversal.com.mx (Mexico), eltiempo.com (Colombia), clarin.com.ar (Argentina), elcomercio.com.pe (Peru), elmercurio.com (Chile), and elpaís.com (Spain). The findings reflect an inconsistent media portrayal, and the coverage was generally found to be superficial, which indicates the need for a more committed approach to the social acceptance of all bodies and to the struggle against aesthetic discrimination suffered by women with non-normative bodies. Full article

The legislative framework of labor law is generally described as gender-neutral based on universal presumptions about employment availability, work productivity, and the ability to work without interruption; in actuality, this gender-neutral framework remains contingent on the existence of the non-menstruating body. This paper analyzes the concept of menstruation as the blind spot in labor law, exploring whether the gender-neutral framework of the legal system has the ability to achieve true gender equality while turning a blind eye to the cyclical body, which has been identified to negatively impact the lives of many menstruators. Methodologically, this research takes a normative approach, incorporating feminist legal theories, principles of substantive equality, and socioeconomic and medical studies on menstruation. The results of this research prove that the concept of menstruation cannot be described or characterized by frameworks such as illness or disability, leaving the normative regulatory space for menstruators to experience structural inequality. The formal equality of labor law rules thus produces unequal effects in practice by privileging an implicit model of uninterrupted work capacity. This article concludes that the legal silence surrounding menstruation is not neutral but reinforces gendered patterns of disadvantage. Making menstruation visible within labor law is therefore not a matter of special treatment but a necessary step towards substantive equality and embodied gender justice, and a prerequisite for any future regulatory responses aimed at addressing workplace inequality. Full article