Dominantly inherited hereditary nonpolyposis colorectal cancer not caused by MMR genes

In the past two decades, multiple studies have been undertaken to elucidate the genetic cause of the predisposition to mismatch repair (MMR)-proficient nonpolyposis colorectal cancer (CRC). Here, we present the proposed candidate genes according to their involvement in specific pathways considered relevant in hereditary CRC and/or colorectal carcinogenesis. To date, only pathogenic variants inRPS20may be convincedly linked to hereditary CRC. Nevertheless, accumulated evidence supports the involvement in the CRC predisposition of other genes, includingMRE11,BARD1,POT1,BUB1B,POLE2,BRF1,IL12RB1,PTPN12, or the epigenetic alteration ofPTPRJ. The contribution of the identified candidate genes to familial/early onset MMR-proficient nonpolyposis CRC, if any, is extremely small, suggesting that other factors, such as the accumulation of low risk CRC alleles, shared environmental exposures, and/or gene-environmental interactions, may explain the missing heritability in CRC

Selective spatial damping of propagating kink wavesto resonant absorption

There is observational evidence of propagating kink waves driven by photospheric motions. These disturbances, interpreted as kink magnetohydrodynamic (MHD) waves are attenuated as they propagate upwards in the solar corona. In this paper we show that resonant absorption provides a simple explanation to the spatial damping of these waves. Kink MHD waves are studied using a cylindrical model of solar magnetic flux tubes which includes a non-uniform layer at the tube boundary. Assuming that the frequency is real and the longitudinal wavenumber complex, the damping length and damping per wavelength produced by resonant absorption are analytically calculated. The damping length of propagating kink waves due resonant absorption is a monotonically decreasing function of frequency. For kink waves with low frequencies the damping length is exactly inversely proportional to frequency and we denote this as the TGV relation. When moving to high frequencies the TGV relation continues to be an exceptionally good approximation of the actual dependency of the damping length on frequency. This dependency means that resonant absorption is selective as it favours low frequency waves and can efficiently remove high frequency waves from a broad band spectrum of kink waves. It is selective as the damping length is inversely proportional to frequency so that the damping becomes more severe with increasing frequency. This means that radial inhomogeneity can cause solar waveguides to be a natural low-pass filter for broadband disturbances. Hence kink wave trains travelling along, e.g., coronal loops, will have a greater proportion of the high frequency components dissipated lower down in the atmosphere. This could have important consequences with respect to the spatial distribution of wave heating in the solar atmospher

Dynamical formation of quantum droplets in a K39 mixture

We report on the dynamical formation of self-bound quantum droplets in attractive mixtures of $^{39}$K atoms. Considering the experimental observations of Semeghini et al., Phys. Rev. Lett. 120, 235301 (2018), we perform numerical simulations to understand the relevant processes involved in the formation of a metastable droplet from an out-of-equilibrium mixture. We first analyze the so-called self-evaporation mechanism, where the droplet dissipates energy by releasing atoms, and then we consider the effects of losses due to three-body recombinations and to the balancing of populations in the mixture. We discuss the importance of these three mechanisms in the observed droplet dynamics and their implications for future experiments

Oscillatory Modes of a Prominence-PCTR-Corona Slab Model

Oscillations of magnetic structures in the solar corona have often been interpreted in terms of magnetohydrodynamic waves. We study the adiabatic magnetoacoustic modes of a prominence plasma slab with a uniform longitudinal magnetic field, surrounded by a prominence-corona transition region (PCTR) and a coronal medium. Considering linear small-amplitude oscillations, the dispersion relation for the magnetoacoustic slow and fast modes is deduced assuming evanescent-like perturbations in the coronal medium. In the system without PCTR, a classification of the oscillatory modes according to the polarisation of their eigenfunctions is made in order to distinguish modes with fast-like or slow-like properties. Internal and external slow modes are governed by the prominence and coronal properties respectively, and fast modes are mostly dominated by prominence conditions for the observed wavelengths. In addition, the inclusion of an isothermal PCTR does not substantially influence the mode frequencies, but new solutions (PCTR slow modes) are present.Comment: Accepted for publication in Solar Physic

Poder, «imperio» y autonomía

El presente trabajo analiza el orden internacional actual mediante un recorte analítico propio que consta de tres dimensiones especiales consideradas como las más relevantes: el poder, su distribución unipolar y los márgenes de autonomía (relacional) de las demás potencias. En este marco, se abordan primeramente las relaciones de poder actuales y sus diferentes manifestaciones. En una segunda sección, se analizan las fuentes estructurales y la esencia del poderío norteamericano, en sus expresiones político-militares (brecha tecnológico- militar), geográfico-estratégicas (balanceador off-shore y control de los espacios comunes globales) y económicas (mecanismos financieros e instituciones internacionales). Finalmente, se analizan los patrones de comportamiento general del resto de los actores relevantes —Rusia, China, Japón, India y la UE— para poder, así, dilucidar sus tendencias a futuro. El trabajo concluye afirmando que, dada la distribución unipolar actual, la gran mayoría de los estados están ejerciendo —tácita o implícitamente- políticas de autonomía relacional, las cuales aún no configuran un «equilibrio de poder blando» porque no se deben a una coordinación de políticas de contraequilibrio, pero que no obstante se irán «endureciendo» proporcionalmente a la profundización de la «unipolaridad imperial» en el sistema político internacional.Mesa Seguridad Internacional: Seguridad Global. La actuación de los EE.UU. en el escenario internacionalInstituto de Relaciones Internacionale

Poder, «imperio» y autonomía

El presente trabajo analiza el orden internacional actual mediante un recorte analítico propio que consta de tres dimensiones especiales consideradas como las más relevantes: el poder, su distribución unipolar y los márgenes de autonomía (relacional) de las demás potencias. En este marco, se abordan primeramente las relaciones de poder actuales y sus diferentes manifestaciones. En una segunda sección, se analizan las fuentes estructurales y la esencia del poderío norteamericano, en sus expresiones político-militares (brecha tecnológico- militar), geográfico-estratégicas (balanceador off-shore y control de los espacios comunes globales) y económicas (mecanismos financieros e instituciones internacionales). Finalmente, se analizan los patrones de comportamiento general del resto de los actores relevantes —Rusia, China, Japón, India y la UE— para poder, así, dilucidar sus tendencias a futuro. El trabajo concluye afirmando que, dada la distribución unipolar actual, la gran mayoría de los estados están ejerciendo —tácita o implícitamente- políticas de autonomía relacional, las cuales aún no configuran un «equilibrio de poder blando» porque no se deben a una coordinación de políticas de contraequilibrio, pero que no obstante se irán «endureciendo» proporcionalmente a la profundización de la «unipolaridad imperial» en el sistema político internacional.Mesa Seguridad Internacional: Seguridad Global. La actuación de los EE.UU. en el escenario internacionalInstituto de Relaciones Internacionale

Poder, «imperio» y autonomía

El presente trabajo analiza el orden internacional actual mediante un recorte analítico propio que consta de tres dimensiones especiales consideradas como las más relevantes: el poder, su distribución unipolar y los márgenes de autonomía (relacional) de las demás potencias. En este marco, se abordan primeramente las relaciones de poder actuales y sus diferentes manifestaciones. En una segunda sección, se analizan las fuentes estructurales y la esencia del poderío norteamericano, en sus expresiones político-militares (brecha tecnológico- militar), geográfico-estratégicas (balanceador off-shore y control de los espacios comunes globales) y económicas (mecanismos financieros e instituciones internacionales). Finalmente, se analizan los patrones de comportamiento general del resto de los actores relevantes —Rusia, China, Japón, India y la UE— para poder, así, dilucidar sus tendencias a futuro. El trabajo concluye afirmando que, dada la distribución unipolar actual, la gran mayoría de los estados están ejerciendo —tácita o implícitamente- políticas de autonomía relacional, las cuales aún no configuran un «equilibrio de poder blando» porque no se deben a una coordinación de políticas de contraequilibrio, pero que no obstante se irán «endureciendo» proporcionalmente a la profundización de la «unipolaridad imperial» en el sistema político internacional.Mesa Seguridad Internacional: Seguridad Global. La actuación de los EE.UU. en el escenario internacionalInstituto de Relaciones Internacionale

Resonantly damped surface and body MHD waves in a solar coronal slab with oblique propagation

The theory of magnetohydrodynamic (MHD) waves in solar coronal slabs in a zero-$\beta$ configuration and for parallel propagation of waves does not allow the existence of surface waves. When oblique propagation of perturbations is considered both surface and body waves are able to propagate. When the perpendicular wave number is larger than a certain value, the body kink mode becomes a surface wave. In addition, a sausage surface mode is found below the internal cut-off frequency. When non-uniformity in the equilibrium is included, surface and body modes are damped due to resonant absorption. In this paper, first, a normal-mode analysis is performed and the period, the damping rate, and the spatial structure of eigenfunctions are obtained. Then, the time-dependent problem is solved, and the conditions under which one or the other type of mode is excited are investigated.Comment: 19 pages, 9 figures, accepted for publication in Solar Physic

The role of initial density profiles in simulations of coronal wave - coronal hole interaction

Interactions between global coronal waves (CWs) and coronal holes (CHs) reveal many interesting features of reflected waves and coronal hole boundaries (CHB) but have fairly been studied so far. Magnetohydrodynamic (MHD) simulations can help us to better understand what is happening during these interaction events, and therefore, to achieve a broader understanding of the parameters involved. In this study, we perform for the first time 2D MHD simulations of a CW-CH interaction including a realistic initial wave density profile that consists of an enhanced as well as a depleted wave part. We vary several initial parameters, such as the initial density amplitudes of the incoming wave, the CH density, and the CHB width, which are all based on actual measurements. We analyse the effects of different incident angles on the interaction features and we use the corresponding time-distance plots to detect specific features of the incoming and the reflected wave. We found that a particular combination of a small CH density, a realistic initial density profile and a sufficiently small incident angle leads to remarkable interaction features, such as a large density amplitude of the reflected wave with respect to the incoming one. The parameter studies in this paper provide a tool to compare time-distance plots based on observational measurements to those created from simulations and therefore enable us to derive interaction parameters from observed CW-CH interaction events that usually cannot be obtained directly. The simulation results in this study are augmented by analytical expressions for the reflection coefficient of the CW-CH interaction which allows us to verify the simulations results in an additional way. This work is the first of a series of studies aiming to finally reconstruct actual observed CW-CH interaction events by means of MHD-simulations

Damping mechanisms for oscillations in solar prominences

Small amplitude oscillations are a commonly observed feature in prominences/filaments. These oscillations appear to be of local nature, are associated to the fine structure of prominence plasmas, and simultaneous flows and counterflows are also present. The existing observational evidence reveals that small amplitude oscillations, after excited, are damped in short spatial and temporal scales by some as yet not well determined physical mechanism(s). Commonly, these oscillations have been interpreted in terms of linear magnetohydrodynamic (MHD) waves, and this paper reviews the theoretical damping mechanisms that have been recently put forward in order to explain the observed attenuation scales. These mechanisms include thermal effects, through non-adiabatic processes, mass flows, resonant damping in non-uniform media, and partial ionization effects. The relevance of each mechanism is assessed by comparing the spatial and time scales produced by each of them with those obtained from observations. Also, the application of the latest theoretical results to perform prominence seismology is discussed, aiming to determine physical parameters in prominence plasmas that are difficult to measure by direct means.Comment: 36 pages, 16 figures, Space Science Reviews (accepted