Studying DNA Double-Strand Break Repair: An Ever-Growing Toolbox

To ward off against the catastrophic consequences of persistent DNA double-strand breaks (DSBs), eukaryotic cells have developed a set of complex signaling networks that detect these DNA lesions, orchestrate cell cycle checkpoints and ultimately lead to their repair. Collectively, these signaling networks comprise the DNA damage response (DDR). The current knowledge of the molecular determinants and mechanistic details of the DDR owes greatly to the continuous development of ground-breaking experimental tools that couple the controlled induction of DSBs at distinct genomic positions with assays and reporters to investigate DNA repair pathways, their impact on other DNA-templated processes and the specific contribution of the chromatin environment. In this review, we present these tools, discuss their pros and cons and illustrate their contribution to our current understanding of the DDR.European Research Council (ERC-2014-CoG 647344

Corruption and entrepreneurship: A bibliometric analysis

The impact of corruption on entrepreneurial dynamics became an attractive topic for scholars after the appearance of public scandals that led to the delegitimization of many governments in the last 40 years. The research that explored the relationship between corruption and entrepreneurship has produced controversial results. It appears that the interaction of these two constructs is influenced by contextual factors both at an individual and national level of analysis. By using a bibliometric methodology and a fractional counting method to analyse the scientific literature on corruption and entrepreneurship, this paper identifies and analyses 180 articles recorded in the Scopus database. It represents a contribution by showing the state of the art of research on corruption and entrepreneurship and proposes future lines of research. Important results have been found about the evolution of the volume of articles and citations on this topic over time. Significant academic interest in this field commenced in the 21st century, and more specifically in the last ten years. This work also provides findings about the most prolific journals, institutions and authors, as well as the most relevant countries, with the United States and United Kingdom leading in terms of the number of publications. In addition, an in-depth analysis of authors' keywords has identified different trends, such as institutions, economic growth, shadow economy, regulation, Africa, culture, economic development, business environment, and informal economy. Finally, some future research lines are proposed, such as institutional theory, tax morale, corruption perceptions, European regions, risk aversion and institutional entrepreneurship

Nanoscale mapping and control of antenna-coupling strength for bright single photon sources

Cavity QED is the art of enhancing light-matter interaction of photon emitters in cavities, with opportunities for sensing, quantum information and energy capture technologies. To boost emitter-cavity interaction, i.e. coupling strength , ultrahigh quality cavities have been concocted yielding photon trapping times of µs to ms. However, such high-Q cavities give poor photon output, hindering applications. To preserve high photon output it is advantageous to strive for highly localised electric fields in radiatively lossy cavities. Nanophotonic antennas are ideal candidates combining low-Q factors with deeply localised mode volumes, allowing large , provided the emitter is positioned exactly right inside the nanoscale mode volume. Here, with nanometre resolution, we map and tune the coupling strength between a dipole nanoantenna-cavity and a single molecule, obtaining a coupling rate of max ~ 200 GHz. Together with accelerated single photon output, this provides ideal conditions for fast and pure non-classical single photon emission with brightness exceeding 10E9 photons/sec. Clearly, nanoantennas acting as “bad” cavities offer an optimal regime for strong coupling , to deliver bright on-demand and ultrafast single photon nanosources for quantum technologies.Peer ReviewedPostprint (author's final draft

Dark matter local density determination: recent observations and future prospects

This report summarises progress made in estimating the local density of dark matter ($\rho_{\mathrm{DM,\odot}}$), a quantity that is especially important for dark matter direct detection experiments. We outline and compare the most common methods to estimate $\rho_{\mathrm{DM,\odot}}$ and the results from recent studies, including those that have benefited from the observations of the ESA/Gaia satellite. The result of most local analyses coincide within a range of $\rho_{\mathrm{DM,\odot}} \simeq \text{0.4--0.6}\,\mathrm{GeV/cm^3} = \text{0.011--0.016}\,\mathrm{M_\odot / pc^3}$, while a slightly lower range of $\rho_{\mathrm{DM,\odot}} \simeq \text{0.3--0.5}\,\mathrm{GeV/cm^3} = \text{0.008--0.013}\,\mathrm{M_\odot / pc^3}$ is preferred by most global studies. In light of recent discoveries, we discuss the importance of going beyond the approximations of what we define as the Ideal Galaxy (a steady-state Galaxy with axisymmetric shape and a mirror symmetry across the mid-plane) in order to improve the precision of $\rho_{\mathrm{DM,\odot}}$ measurements. In particular, we review the growing evidence for local disequilibrium and broken symmetries in the present configuration of the Milky Way, as well as uncertainties associated with the Galactic distribution of baryons. Finally, we comment on new ideas that have been proposed to further constrain the value of $\rho_{\mathrm{DM,\odot}}$, most of which would benefit from Gaia's final data release.Comment: 37 pages, 3 tables, 1 figure. Invited report article for Reports on Progress in Physic

Solution of a model of SAW's with multiple monomers per site on the Husimi lattice

We solve a model of self-avoiding walks which allows for a site to be visited up to two times by the walk on the Husimi lattice. This model is inspired in the Domb-Joyce model and was proposed to describe the collapse transition of polymers with one-site interactions only. We consider the version in which immediate self-reversals of the walk are forbidden (RF model). The phase diagram we obtain for the grand-canonical version of the model is similar to the one found in the solution of the Bethe lattice, with two distinct polymerized phases, a tricritical point and a critical endpoint.Comment: 16 pages, including 6 figure