AMI-CL J0300+2613: A Galactic anomalous-microwave-emission ring masquerading as a galaxy cluster

The Arcminute Microkelvin Imager (AMI) carried out a blind survey for galaxy clusters via their Sunyaev-Zel'dovich effect decrements between 2008 and 2011. The first detection, known as AMI-CL J0300+2613, has been reobserved with AMI equipped with a new digital correlator with high dynamic range. The combination of the new AMI data and more recent high-resolution sub-mm and infra-red maps now shows the feature in fact to be a ring of positive dust-correlated Galactic emission, which is likely to be anomalous microwave emission (AME). If so, this is the first completely blind detection of AME at arcminute scales

AMI-LA observations of the SuperCLASS supercluster

We present a deep survey of the SuperCLASS super-cluster - a region of sky known to contain five Abell clusters at redshift $z\sim0.2$ - performed using the Arcminute Microkelvin Imager (AMI) Large Array (LA) at 15.5$~$GHz. Our survey covers an area of approximately 0.9 square degrees. We achieve a nominal sensitivity of $32.0~\mu$Jy beam$^{-1}$ toward the field centre, finding 80 sources above a $5\sigma$ threshold. We derive the radio colour-colour distribution for sources common to three surveys that cover the field and identify three sources with strongly curved spectra - a high-frequency-peaked source and two GHz-peaked-spectrum sources. The differential source count (i) agrees well with previous deep radio source count, (ii) exhibits no evidence of an emerging population of star-forming galaxies, down to a limit of 0.24$~$mJy, and (iii) disagrees with some models of the 15$~$GHz source population. However, our source count is in agreement with recent work that provides an analytical correction to the source count from the SKADS Simulated Sky, supporting the suggestion that this discrepancy is caused by an abundance of flat-spectrum galaxy cores as-yet not included in source population models

Potential climatic transitions with profound impact on Europe

We discuss potential transitions of six climatic subsystems with large-scale impact on Europe, sometimes denoted as tipping elements. These are the ice sheets on Greenland and West Antarctica, the Atlantic thermohaline circulation, Arctic sea ice, Alpine glaciers and northern hemisphere stratospheric ozone. Each system is represented by co-authors actively publishing in the corresponding field. For each subsystem we summarize the mechanism of a potential transition in a warmer climate along with its impact on Europe and assess the likelihood for such a transition based on published scientific literature. As a summary, the ‘tipping’ potential for each system is provided as a function of global mean temperature increase which required some subjective interpretation of scientific facts by the authors and should be considered as a snapshot of our current understanding. <br/

Exosomes derived from mesenchymal stem cells enhance radiotherapy-induced cell death in tumor and metastatic tumor foci

We have recently shown that radiotherapy may not only be a successful local and regional treatment but, when combined with MSCs, may also be a novel systemic cancer therapy. This study aimed to investigate the role of exosomes derived from irradiated MSCs in the delay of tumor growth and metastasis after treatment with MSC + radiotherapy (RT). The tumor cell loss rates found after treatment with the combination of MSC and RT and for exclusive RT, were: 44.4% % and 12,1%, respectively. Concomitant and adjuvant use of RT and MSC, increased the mice surviving time 22,5% in this group, with regard to the group of mice treated with exclusive RT and in a 45,3% respect control group. Moreover, the number of metastatic foci found in the internal organs of the mice treated with MSC + RT was 60% less than the mice group treated with RT alone. We reasoned that the exosome secreted by the MSC, could be implicated in tumor growth delay and metastasis control after treatment. Our results show that exosomes derived form MSCs, combined with radiotherapy, are determinant in the enhancement of radiation effects observed in the control of metastatic spread of melanoma cells and suggest that exosome-derived factors could be involved in the bystander, and abscopal effects found after treatment of the tumors with RT plus MSC. Radiotherapy itself may not be systemic, although it might contribute to a systemic effect when used in combination with mesenchymal stem cells owing the ability of irradiated MSCs-derived exosomes to increase the control of tumor growth and metastasis.This work was supported by CNPq, Conselho Nacional de Desenvolvimento Científico e Tecnológico – Brasil, Junta de Andalucía, project of Excellence from Junta de Andalucía P12-CTS-383 to FJO, Spanish Ministry of Economy and Competitiveness SAF2015-70520-R to FJO and JMRdA, RTICC RD12/0036/0026 and CIBER Cáncer ISCIII CB16/12/00421 to FJO

Simulating the midlatitude atmospheric circulation: what might we gain from high-resolution modeling of air-sea interactions?

Purpose of Review. To provide a snapshot of the current research on the oceanic forcing of the atmospheric circulation in midlatitudes and a concise update on previous review papers. Recent findings. Atmospheric models used for seasonal and longer timescales predictions are starting to resolve motions so far only studied in conjunction with weather forecasts. These phenomena have horizontal scales of ~ 10–100 km which coincide with energetic scales in the ocean circulation. Evidence has been presented that, as a result of this matching of scale, oceanic forcing of the atmosphere was enhanced in models with 10–100 km grid size, especially at upper tropospheric levels. The robustness of these results and their underlying mechanisms are however unclear. Summary. Despite indications that higher resolution atmospheric models respond more strongly to sea surface temperature anomalies, their responses are still generally weaker than those estimated empirically from observations. Coarse atmospheric models (grid size greater than 100 km) will miss important signals arising from future changes in ocean circulation unless new parameterizations are developed

Progress on lead-free metal halide perovskites for photovoltaic applications: a review

ABSTRACT: Metal halide perovskites have revolutionized the field of solution-processable photovoltaics. Within just a few years, the power conversion efficiencies of perovskite-based solar cells have been improved significantly to over 20%, which makes them now already comparably efficient to silicon-based photovoltaics. This breakthrough in solution-based photovoltaics, however, has the drawback that these high efficiencies can only be obtained with lead-based perovskites and this will arguably be a substantial hurdle for various applications of perovskite-based photovoltaics and their acceptance in society, even though the amounts of lead in the solar cells are low. This fact opened up a new research field on lead-free metal halide perovskites, which is currently remarkably vivid. We took this as incentive to review this emerging research field and discuss possible alternative elements to replace lead in metal halide perovskites and the properties of the corresponding perovskite materials based on recent theoretical and experimental studies. Up to now, tin-based perovskites turned out to be most promising in terms of power conversion efficiency; however, also the toxicity of these tin-based perovskites is argued. In the focus of the research community are other elements as well including germanium, copper, antimony, or bismuth, and the corresponding perovskite compounds are already showing promising properties. GRAPHICAL ABSTRACT: [Image: see text

Lorentz’ force as a Tool for physics inquiry: studying particle tracks in cloud and streamer chambers

A sequence of experiments aimed at exploring magnetic force on moving charged particles is presented. At first students work with equipment that reproduces Thomson’s experiment of 1932. Afterwards they analyze images of sub-nuclear particle tracks in cloud and streamer chambers in historical experiments. The sequence has been tested with high school students. Our results compared with the ones reported in the literature indicate that students’ understanding of the direction and magnitude of the magnetic force markedly improved and some typical difficulties were overcome