On mini-halo encounters with stars

We study, analytically and numerically, the energy input into dark matter mini-haloes by interactions with stars. We find that the fractional energy input in simulations of Plummer spheres agrees well with the impulse approximation for small and large impact parameters, with a rapid transition between these two regimes. Using the impulse approximation, the fractional energy input at large impact parameters is fairly independent of the mass and density profiles of the mini-halo; however, low-mass mini-haloes experience a greater fractional energy input in close encounters. We formulate a fitting function which encodes these results and use it to estimate the disruption time-scales of mini-haloes, taking into account the stellar velocity dispersion and mass distribution. For mini-haloes with mass formula on typical orbits which pass through the disc, we find that the estimated disruption time-scales are independent of mini-halo mass, and are of the order of the age of the Milky Way. For more massive mini-haloes, the estimated disruption time-scales increase rapidly with increasing mass

A study of the centrally produced phiphi system in pp interactions at 450 GeV/c

The reaction pp to pfps(K+K-K+K-) in which the K+K-K+K- system is centrally produced has been studied at 450 GeV/c. Phi phi production has been found to dominate this reaction and is compatible with being produced by double Pomeron exchange. An angular analysis of the phi phi system favours JPC = 2++ and its dPT dependence is similar to that observed for glueball candidates.Comment: 11 pages, Latex, 4 Figure

Probing Jet Launching in Neutron Star X-Ray Binaries: The Variable and Polarized Jet of SAX J1808.4-3658

Indexación ScopusWe report on an optical photometric and polarimetric campaign on the accreting millisecond X-ray pulsar (AMXP) x display--inline-block" style="background: var(--highlight-yellow); color: inherit;">SAX x display--inline-block" style="background: var(--highlight-yellow); color: inherit;">4-x display--inline-block" style="background: var(--highlight-yellow); color: inherit;">J1808.x display--inline-block" style="background: var(--highlight-yellow); color: inherit;">4-x display--inline-block" style="background: var(--highlight-yellow); color: inherit;">3658 during its 2019 outburst. The emergence of a low-frequency excess x display--inline-block" style="background: var(--highlight-yellow); color: inherit;">in the spectral energy distribution x display--inline-block" style="background: var(--highlight-yellow); color: inherit;">in the form of a red excess above the disk spectrum (seen most prominently x display--inline-block" style="background: var(--highlight-yellow); color: inherit;">in the z, i, and R bands) is observed as the outburst evolves. This is indicative of optically thin synchrotron emission due to a jet, as seen previously x display--inline-block" style="background: var(--highlight-yellow); color: inherit;">in this source and x display--inline-block" style="background: var(--highlight-yellow); color: inherit;">in other AMXPs during outburst. At the end of the outburst decay, the source enters a reflaring state. The low-frequency excess is still observed during the reflares. Our optical (BVRI) polarimetric campaign shows variable linear polarization (LP) throughout the outburst. We show that this is intrinsic to the source, with low-level but significant detections (0.2%-2%) x display--inline-block" style="background: var(--highlight-yellow); color: inherit;">in all bands. The LP spectrum is red during both the main outburst and the reflaring state, favoring a jet origin for this variable polarization over other interpretations, such as Thomson scattering with free electrons from the disk or the propelled matter. During the reflaring state, a few episodes with stronger LP levels (1%-2%) are observed. The low-level, variable LP is suggestive of strongly tangled magnetic fields near the base of the jet. These results clearly demonstrate how polarimetry is a powerful tool for x display--inline-block" style="background: var(--highlight-yellow); color: inherit;">probing the magnetic field structure x display--inline-block" style="background: var(--highlight-yellow); color: inherit;">in X-ray binary jets, as for active galactic nuclei jets. © 2020. The American Astronomical Society. All rights reserved..https://iopscience-iop-org.recursosbiblioteca.unab.cl/article/10.3847/1538-4357/abc68

The evolution of language: a comparative review

For many years the evolution of language has been seen as a disreputable topic, mired in fanciful "just so stories" about language origins. However, in the last decade a new synthesis of modern linguistics, cognitive neuroscience and neo-Darwinian evolutionary theory has begun to make important contributions to our understanding of the biology and evolution of language. I review some of this recent progress, focusing on the value of the comparative method, which uses data from animal species to draw inferences about language evolution. Discussing speech first, I show how data concerning a wide variety of species, from monkeys to birds, can increase our understanding of the anatomical and neural mechanisms underlying human spoken language, and how bird and whale song provide insights into the ultimate evolutionary function of language. I discuss the ‘‘descended larynx’ ’ of humans, a peculiar adaptation for speech that has received much attention in the past, which despite earlier claims is not uniquely human. Then I will turn to the neural mechanisms underlying spoken language, pointing out the difficulties animals apparently experience in perceiving hierarchical structure in sounds, and stressing the importance of vocal imitation in the evolution of a spoken language. Turning to ultimate function, I suggest that communication among kin (especially between parents and offspring) played a crucial but neglected role in driving language evolution. Finally, I briefly discuss phylogeny, discussing hypotheses that offer plausible routes to human language from a non-linguistic chimp-like ancestor. I conclude that comparative data from living animals will be key to developing a richer, more interdisciplinary understanding of our most distinctively human trait: language

Personalized peptide-based vaccination for treatment of colorectal cancer: rational and progress

Colorectal cancer (CRC) is one of the most common cancers globally and is associated with a high rate of morbidity and mortality. A large proportion of patients with early stage CRC who undergo conventional treatments develop local recurrence or distant metastasis and in this group of advanced disease, the survival rate is low. Furthermore there is often a poor response and/or toxicity associated with chemotherapy and chemo-resistance may limit continuing conventional treatment alone. Choosing novel and targeted therapeutic approaches based on clinicopathological and molecular features of tumors in combination with conventional therapeutic approach could be used to eradicate residual micrometastasis and therefore improve patient prognosis and also be used preventively. Peptide-based vaccination therapy is one class of cancer treatment that could be used to induce tumor-specific immune responses, through the recognition of specific antigen-derived peptides in tumor cells, and this has emerged as a promising anti-cancer therapeutic strategy. The aim of this review was to summarize the main findings of recent studies in exciting field of peptide-based vaccination therapy in CRC patients as a novel therapeutic approach in treatment of CRC

Integrating social and facial models of person perception : Converging and diverging dimensions

Models of first impressions from faces have consistently found two underlying dimensions of trustworthiness and dominance. These dimensions show apparent parallels to social psychological models of inter-group perception that describe dimensions of warmth (cf. trustworthiness) and competence (cf. dominance), and it has been suggested that they reflect universal dimensions of social cognition. We investigated whether the dimensions from face and inter-group social perception models are indeed equivalent by evaluating first impressions of faces. Across four studies with differing methods we consistently found that while perceptions of trustworthiness and warmth were closely related, perceptions of dominance and competence were less strongly related. Taken together, our results demonstrate strong similarity on the first dimension across facial and social models, with less similarity on the second dimension. We suggest that facial impressions of competence and dominance may represent different routes to judging a stranger's capability to help or harm