Mouse models of breast cancer metastasis

Metastatic spread of cancer cells is the main cause of death of breast cancer patients, and elucidation of the molecular mechanisms underlying this process is a major focus in cancer research. The identification of appropriate therapeutic targets and proof-of-concept experimentation involves an increasing number of experimental mouse models, including spontaneous and chemically induced carcinogenesis, tumor transplantation, and transgenic and/or knockout mice. Here we give a progress report on how mouse models have contributed to our understanding of the molecular processes underlying breast cancer metastasis and on how such experimentation can open new avenues to the development of innovative cancer therapy

Observation of Two New Excited Ξb0 States Decaying to Λb0 K-π+

Two narrow resonant states are observed in the Λb0K-π+ mass spectrum using a data sample of proton-proton collisions at a center-of-mass energy of 13 TeV, collected by the LHCb experiment and corresponding to an integrated luminosity of 6 fb-1. The minimal quark content of the Λb0K-π+ system indicates that these are excited Ξb0 baryons. The masses of the Ξb(6327)0 and Ξb(6333)0 states are m[Ξb(6327)0]=6327.28-0.21+0.23±0.12±0.24 and m[Ξb(6333)0]=6332.69-0.18+0.17±0.03±0.22 MeV, respectively, with a mass splitting of Δm=5.41-0.27+0.26±0.12 MeV, where the uncertainties are statistical, systematic, and due to the Λb0 mass measurement. The measured natural widths of these states are consistent with zero, with upper limits of Γ[Ξb(6327)0]<2.20(2.56) and Γ[Ξb(6333)0]<1.60(1.92) MeV at a 90% (95%) credibility level. The significance of the two-peak hypothesis is larger than nine (five) Gaussian standard deviations compared to the no-peak (one-peak) hypothesis. The masses, widths, and resonant structure of the new states are in good agreement with the expectations for a doublet of 1D Ξb0 resonances

TESS Discovery of a Super-Earth and Three Sub-Neptunes Hosted by the Bright, Sun-like Star HD 108236

We report the discovery and validation of four extrasolar planets hosted by the nearby, bright, Sun-like (G3V) star HD 108236 using data from the Transiting Exoplanet Survey Satellite (TESS). We present transit photometry, reconnaissance, and precise Doppler spectroscopy, as well as high-resolution imaging, to validate the planetary nature of the objects transiting HD 108236, also known as the TESS Object of Interest (TOI) 1233. The innermost planet is a possibly rocky super-Earth with a period of days and has a radius of 1.586 ± 0.098 R⊕. The outer planets are sub-Neptunes, with potential gaseous envelopes, having radii of R⊕, 2.72 ± 0.11 R⊕, and R⊕ and periods of days, days, and days, respectively. With V and Ks magnitudes of 9.2 and 7.6, respectively, the bright host star makes the transiting planets favorable targets for mass measurements and, potentially, for atmospheric characterization via transmission spectroscopy. HD 108236 is the brightest Sun-like star in the visual (V) band known to host four or more transiting exoplanets. The discovered planets span a broad range of planetary radii and equilibrium temperatures and share a common history of insolation from a Sun-like star (R⋆ = 0.888 ± 0.017 R⊙, Teff = 5730 ± 50 K), making HD 108236 an exciting, opportune cosmic laboratory for testing models of planet formation and evolution

TOI-431/HIP 26013: a super-Earth and a sub-Neptune transiting a bright, early K dwarf, with a third RV planet

We present the bright (Vmag = 9.12), multiplanet system TOI-431, characterized with photometry and radial velocities (RVs). We estimate the stellar rotation period to be 30.5 ± 0.7 d using archival photometry and RVs. Transiting Exoplanet Survey Satellite (TESS) objects of Interest (TOI)-431 b is a super-Earth with a period of 0.49 d, a radius of 1.28 ± 0.04 R⊕, a mass of 3.07 ± 0.35 M⊕, and a density of 8.0 ± 1.0 g cm−3; TOI-431 d is a sub-Neptune with a period of 12.46 d, a radius of 3.29 ± 0.09 R⊕, a mass of 9.90+1.53−1.49 M⊕, and a density of 1.36 ± 0.25 g cm−3. We find a third planet, TOI-431 c, in the High Accuracy Radial velocity Planet Searcher RV data, but it is not seen to transit in the TESS light curves. It has an Msin i of 2.83+0.41−0.34 M⊕, and a period of 4.85 d. TOI-431 d likely has an extended atmosphere and is one of the most well-suited TESS discoveries for atmospheric characterization, while the super-Earth TOI-431 b may be a stripped core. These planets straddle the radius gap, presenting an interesting case-study for atmospheric evolution, and TOI-431 b is a prime TESS discovery for the study of rocky planet phase curves

Direct evidence of fluid mixing in the formation of stratabound Pb–Zn–Ba–F mineralisation in the Alston Block, North Pennine Orefield (England)

The North Pennine Orefield Alston Block has produced approximately 4 Mt Pb, 0.3 Mt Zn, 2.1 Mt fluorite, 1.5 Mt barite, 1 Mt witherite, plus a substantial amount of iron ore and copper ore from predominantly vein-hosted mineralisation in Carboniferous limestones. However, a significant proportion of this production (ca. 20%) came from stratabound deposits. Though much is known about the vein mineralisation, the relationship between the veins and the stratabound mineralisation is not well-understood. New petrographic, isotopic and fluid inclusion data derived from samples of stratabound mineralisation allow us to present a unified model that addresses the genesis of both the vein and stratabound styles of mineralisation. The mineralisation can be considered in terms of three episodes: 1. Dolomitisation and ankeritisation Limestones in the vicinity of the stratabound mineralisation were pervasively dolomitised/ankeritised, and developed vuggy porosity in the presence of a high-salinity brine consistent with fluids derived from adjacent mud and shale-filled basins. 2. Main stage fluorite–quartz–sulphide mineralisation Metasomatism of limestone was accompanied by brecciation, dissolution and hydrothermal karstification with modification of the existing pore system. The open space was filled with fluorite, galena, sphalerite, quartz and barite, formed in response to mixing of lowsalinity sodic groundwater with high-salinity calcic brine with elevated metal contents (particularly Fe up to 7,000 ppm) relative to “normal” high total dissolved solids sedimentary brines. 3. Late-stage barite mineralisation paragenetically appears to represent either the waning stages or the distal portions of the main hydrothermal circulation system under cooler conditions

Ground-based detection of G star superflares with NGTS

We present high cadence detections of two superflares from a bright G8 star (V = 11.56) with the Next Generation Transit Survey (NGTS). We improve upon previous superflare detections by resolving the flare rise and peak, allowing us to fit a solar flare inspired model without the need for arbitrary break points between rise and decay. Our data also enables us to identify substructure in the flares. From changing star-spot modulation in the NGTS data, we detect a stellar rotation period of 59 h, along with evidence for differential rotation. We combine this rotation period with the observed ROSAT X-ray flux to determine that the star’s X-ray activity is saturated. We calculate the flare bolometric energies as 5.4 + 0.8 −0.7 ×1034 and 2.6 + 0.4 −0.3 × 1034 erg and compare our detections with G star superflares detected in the Kepler survey. We find our main flare to be one of the largest amplitude superflares detected from a bright G star. With energies more than 100 times greater than the Carrington event, our flare detections demonstrate the role that ground-based instruments such as NGTS can have in assessing the habitability of Earth-like exoplanets, particularly in the era of PLATO