Blue large-amplitude pulsators (BLAPs) are blue stars emitting high-amplitude (> 0.2 mag) pulsations on a timescale of a few tens of minutes. Recently discovered using OGLE data, they form a new ...class of variable star and have inspired a number of investigations searching for the origin of their pulsations. This short study presents the Gaia DR2 data for ten BLAPs for which parallax measurements are available. We have dereddened their colours using Gaia DR2 data from the stars in their immediate field and find that six show absolute magnitude and intrinsic colour consistent with expectations, whilst four stars have a less certain classification. This work highlights the extra information that Gaia DR2 data can provide to help classify those variable stars for which moderate-resolution optical spectra are not currently available. We also show how Gaia DR2 can make searches for BLAPs in wide-field high-cadence surveys more systematic and robust.
ABSTRACT
Superflares on solar-type stars have been a rapidly developing field ever since the launch of Kepler. Over the years, there have been several studies investigating the statistics of these ...explosive events. In this study, we present a statistical analysis of stellar flares on solar-type stars made using photometric data in 2-min cadence from Transiting Exoplanet Survey Satellite of the whole Southern hemisphere (sectors 1–13). We derive rotational periods for all the stars in our sample from rotational modulations present in the light curve as a result of large star-spot(s) on the surface. We identify 1980 stellar flares from 209 solar-type stars with energies in the range of 1031–1036 erg (using the solar flare classification, this corresponds to X1–X100 000) and conduct an analysis into their properties. We investigate the rotational phase of the flares and find no preference for any phase, suggesting the flares are randomly distributed. As a benchmark, we use GOES data of solar flares to detail the close relationship between solar flares and sunspots. In addition, we also calculate approximate spot areas for each of our stars and compare this to flare number, rotational phase, and flare energy. Additionally, two of our stars were observed in the continuous viewing zone with light-curves spanning 1 yr; as a result we examine the stellar variability of these stars in more detail.
Drugs that target intracellular signalling pathways have markedly improved progression-free survival of patients with cancers who were previously regarded as untreatable. However, the rapid emergence ...of therapeutic resistance, as a result of bypass signalling or downstream mutation within kinase-mediated signalling cascades, has curtailed the benefit gained from these therapies. Such resistance mechanisms are facilitated by the linearity and redundancy of kinase signalling pathways. We argue that, in each cancer, the dysregulation of key transcriptional regulators not only defines the cancer phenotype but is essential for its development and maintenance. Furthermore, we propose that, as therapeutic targets, these transcriptional regulators are less prone to bypass by alternative mutational events or clonal heterogeneity, and therefore we must rekindle our efforts to directly target transcriptional regulation across a broad range of cancers.
ABSTRACT
Detailed studies of the Sun have shown that sunspots and solar flares are closely correlated. Photometric data from Kepler/K2 has allowed similar studies to be carried out on other stars. ...Here, we utilize Transiting Exoplanet Survey Satellite (TESS) photometric 2-min cadence of 167 low-mass stars from Sectors 1 to 3 to investigate the relationship between star-spots and stellar flares. From our sample, 90 per cent show clear rotational modulation likely due to the presence of a large, dominant star-spot and we use this to determine a rotational period for each star. Additionally, each low-mass star shows one or more flares in its light curve and using Gaia Data Release 2 parallaxes and SkyMapper magnitudes we can estimate the energy of the flares in the TESS band-pass. Overall, we have 1834 flares from the 167 low-mass stars with energies from 6.0 × 1029 to 2.4 × 1035 erg. We find none of the stars in our sample show any preference for rotational phase, suggesting the lack of a correlation between the large, dominant star-spot, and flare number. We discuss this finding in greater detail and present further scenarios to account for the origin of flares on these low-mass stars.
We examine the relationship between superoutburst duration tdur and orbital period Porb in AM CVn ultra-compact binary systems. We show that the previously determined steep relation derived by ...Levitan et al. was strongly influenced by the inclusion of upper limits for systems with a relatively long orbital period in their fit. Excluding the upper limit values and including tdur values for three systems at long Porb that were not considered previously, then is flat as predicted by Cannizzo & Nelemans.
Accumulating evidence suggests that the tumor microenvironment (TME) is involved in disease progression and drug resistance in B cell malignancies, by supporting tumor growth and facilitating the ...ability of malignant cells to avoid immune recognition. Immunomodulatory drugs (IMiDs) such as lenalidomide have some direct anti-tumor activity, but critically also target various cellular compartments of the TME including T cells, NK cells, and stromal cells, which interfere with pro-tumor signaling while activating anti-tumor immune responses. Lenalidomide has delivered favorable clinical outcomes as a single-agent, and in combination therapy leads to durable responses in chronic lymphocytic leukemia (CLL) and several non-Hodgkin lymphomas (NHLs) including follicular lymphoma (FL), diffuse large B cell lymphoma (DLBCL), and mantle cell lymphoma (MCL). Recently, avadomide, a next generation cereblon E3 ligase modulator (CELMoD), has shown potent anti-tumor and TME immunomodulatory effects, as well as promising clinical efficacy in DLBCL. This review describes how the pleiotropic effects of IMiDs and CELMoDs could make them excellent candidates for combination therapy in the immuno-oncology era—a concept supported by preclinical data, as well as the recent approval of lenalidomide in combination with rituximab for the treatment of relapsed/refractory (R/R) FL.
The tumor microenvironment (TME) plays an essential role in the development, growth, and survival of the malignant B-cell clone in chronic lymphocytic leukemia (CLL). Within the proliferation niches ...of lymph nodes, bone marrow, and secondary lymphoid organs, a variety of phenotypically and functionally altered cell types, including T cells, natural killer cells, monocytes/macrophages, endothelial and mesenchymal stroma cells, provide crucial survival signals, along with CLL-cellinduced suppression of antitumor immune responses. The B-cell receptor pathway plays a pivotal role in mediating the interaction between CLL cells and the TME. However, an increasing number of additional components of the multifactorial TME are being discovered. Although the majority of therapeutic strategies employed in CLL hitherto have focused on targeting the leukemic cells, emerging evidence implies that modulation of microenvironmental cells and CLL-TME interactions by novel therapeutic agents significantly affect their clinical efficacy. Thus, improving our understanding of CLL-TME interactions and how they are affected by current therapeutic agents may improve and guide treatment strategies. Identification of novel TME interactions may also pave the road for the development of novel therapeutic strategies targeting the TME. In this review, we summarize current evidence on the effects of therapeutic agents on cells and interactions within the TME. With a growing demand for improved and personalized treatment options in CLL, this review aims at inspiring future exploration of smart drug combination strategies, translational studies, and novel therapeutic targets in clinical trials.
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