The Dual Role of Outflows in Quenching Satellites of Low-Mass Hosts: NGC 3109

While dwarf galaxies observed in the field are overwhelmingly star-forming, dwarf galaxies in environments as dense or denser than the Milky Way are overwhelmingly quenched. In this paper, we explore quenching in the lower density environment of the Small-Magellanic-Cloud-mass galaxy NGC 3109 ($\text{M}_* \sim 10^8 \, \text{M}_\odot$), which hosts two known dwarf satellite galaxies (Antlia and Antlia B), both of which are HI deficient compared to similar galaxies in the field and have recently stopped forming stars. Using a new semi-analytic model in concert with the measured star formation histories and gas masses of the two dwarf satellite galaxies, we show that they could not have been quenched solely by direct ram pressure stripping of their interstellar media, as is common in denser environments. Instead, we find that separation of the satellites from pristine gas inflows, coupled with stellar-feedback-driven outflows from the satellites (jointly referred to as the starvation quenching model), can quench the satellites on timescales consistent with their likely infall times into NGC 3109's halo. It is currently believed that starvation is caused by "weak" ram pressure that prevents low-density, weakly-bound gas from being accreted onto the dwarf satellite, but cannot directly remove the denser interstellar medium. This suggests that star-formation-driven outflows serve two purposes in quenching satellites in low-mass environments: outflows from the host form a low-density circumgalactic medium that cannot directly strip the interstellar media from its satellites, but is sufficient to remove loosely-bound gaseous outflows from the dwarf satellites driven by their own star formation.Comment: 20 pages and 2 appendices. To be submitted to MNRAS. Comments welcome

Low-density star cluster formation: Discovery of a young faint fuzzy on the outskirts of the low-mass spiral galaxy NGC 247

The classical globular clusters found in all galaxy types have half-light radii of rh ~2-4 pc, which have been tied to formation in the dense cores of giant molecular clouds. Some old star clusters have larger sizes, and it is unclear if these represent a fundamentally different mode of low-density star cluster formation. We report the discovery of a rare, young \u27faint fuzzy\u27 star cluster, NGC 247-SC1, on the outskirts of the low-mass spiral galaxy NGC 247 in the nearby Sculptor group, and measure its radial velocity using Keck spectroscopy. We use Hubble Space Telescope imaging to measure the cluster half-light radius of rh ≃ 12 pc and a luminosity of LV ≃ 4 × 105Lθ. We produce a colour-magnitude diagram of cluster stars and compare to theoretical isochrones, finding an age of ≃300 Myr, a metallicity of [Z/H] ~-0.6 and an inferred mass of M∗ ≃ 9 × 104Mθ. The narrow width of blue-loop star magnitudes implies an age spread of ≲50 Myr, while no old red-giant branch stars are found, so SC1 is consistent with hosting a single stellar population, modulo several unexplained bright \u27red straggler\u27 stars. SC1 appears to be surrounded by tidal debris, at the end of an ∼2 kpc long stellar filament that also hosts two low-mass, low-density clusters of a similar age. We explore a link between the formation of these unusual clusters and an external perturbation of their host galaxy, illuminating a possible channel by which some clusters are born with large sizes

Representative Landscapes in the Forested Area of Canada

Canada is a large nation with forested ecosystems that occupy over 60% of the national land base, and knowledge of the patterns of Canada’s land cover is important to proper environmental management of this vast resource. To this end, a circa 2000 Landsat-derived land cover map of the forested ecosystems of Canada has created a new window into understanding the composition and configuration of land cover patterns in forested Canada. Strategies for summarizing such large expanses of land cover are increasingly important, as land managers work to study and preserve distinctive areas, as well as to identify representative examples of current land-cover and land-use assemblages. Meanwhile, the development of extremely efficient clustering algorithms has become increasingly important in the world of computer science, in which billions of pieces of information on the internet are continually sifted for meaning for a vast variety of applications. One recently developed clustering algorithm quickly groups large numbers of items of any type in a given data set while simultaneously selecting a representative—or “exemplar”—from each cluster. In this context, the availability of both advanced data processing methods and a nationally available set of landscape metrics presents an opportunity to identify sets of representative landscapes to better understand landscape pattern, variation, and distribution across the forested area of Canada. In this research, we first identify and provide context for a small, interpretable set of exemplar landscapes that objectively represent land cover in each of Canada’s ten forested ecozones. Then, we demonstrate how this approach can be used to identify flagship and satellite long-term study areas inside and outside protected areas in the province of Ontario. These applications aid our understanding of Canada’s forest while augmenting its management toolbox, and may signal a broad range of applications for this versatile approach

The effect of neutropenia on patient-reported functioning and quality of life (QOL) among palbociclib participants of the MADELINE study

1064 Background: MADELINE is an observational, multicenter study of women with HR+/HER2- advanced or metastatic breast cancer who were followed for 6 months to evaluate patient reported QOL after initiating palbociclib combination therapy or other approved treatment in the US. A novel mobile application was developed to capture PROs for QOL at daily, weekly, monthly/cycle-based intervals for up to 6 months. QOL measures were evaluated to determine if palbociclib-treated patients experiencing episodes of neutropenia had associated decreases in QOL compared to patients without episodes of neutropenia. Methods: Patients completed the SF-12 and CES-D-10 at baseline and each cycle. Change from baseline was assessed using mean scores and mixed-effects models. Daily pain and fatigue severity were measured on an 11-point scale (0-10, 10 being worst possible pain/fatigue) and averaged to create weekly scores. Patients indicated weekly how breast cancer or its treatment interfered with family/social life, productivity, physical activity and energy on a 5-point scales (from not at all to a great deal). Demographic and clinical data including adverse events were recorded in an eCRF. Results: 25 sites contributed 139 patients (median [range] age 60 [34, 82]; white: 83%; ECOG 0-1: 87%). During the 6-month follow up period, 45% of patients experienced ≥1 neutropenia event (grade 1-4: 17%, 27%, 24%, 2%) and 11% had an event resulting in a dose change. Least-square (LS) mean change from baseline to end of study for the SF-12 Physical/Mental Component summaries (PCS/MCS) and the CES-D-10 showed no association between neutropenia and decreased QOL. Daily pain/fatigue was relatively stable for those with neutropenia (cycle 1, week 1: 2.8 [1.95] and 1.8 [0.95]; cycle 6, week 1: 2.4 [1.95] and 2.3 [1.59]) and those without (cycle 1, week 1: 2.2 [2.46] and 2.8 [2.39]; cycle 6, week 1: 1.6 [2.29] and 2.4 [2.22]). There was no significant change for impact of breast cancer or treatment across cycles. Conclusions: Patients with neutropenia did not experience decreased QOL compared to patients without neutropenia nor did patients as a whole experience numerically or clinically meaningful decrease in QOL throughout the follow up period. Daily PROs collected suggest a low level of pain/fatigue that did not change substantially over time. [Table: see text

Deep Subaru Hyper Suprime-Cam Observations of Milky Way Satellites Columba I and Triangulum II*

We present deep, wide-field Subaru Hyper Suprime-Cam photometry of two recently discovered satellites of the Milky Way (MW): Columba I (Col I) and Triangulum II (Tri II). The color–magnitude diagrams of both objects point to exclusively old and metal-poor stellar populations. We re-derive structural parameters and luminosities of these satellites, and find for Col I and for Tri II, with corresponding half-light radii of pc and pc. The properties of both systems are consistent with observed scaling relations for MW dwarf galaxies. Based on archival data, we derive upper limits on the neutral gas content of these dwarfs, and find that they lack H i, as do the majority of observed satellites within the MW virial radius. Neither satellite shows evidence of tidal stripping in the form of extensions or distortions in matched-filter stellar density maps or surface-density profiles. However, the smaller Tri II system is relatively metal-rich for its luminosity (compared to other MW satellites), possibly because it has been tidally stripped. Through a suite of orbit simulations, we show that Tri II is approaching pericenter of its eccentric orbit, a stage at which tidal debris is unlikely to be seen. In addition, we find that Tri II may be on its first infall into the MW, which helps explain its unique properties among MW dwarfs. Further evidence that Tri II is likely an ultra-faint dwarf comes from its stellar mass function, which is similar to those of other MW dwarfs

A prospective observational study of patient-reported functioning and quality of life in advanced and metastatic breast cancer utilizing a novel mobile application

PURPOSETo assess and describe patient-reported outcomes (PROs) in women with locally advanced/unresectable or metastatic breast cancer (aBC/mBC) with hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR + /HER2 -) status receiving palbociclib combination therapy in a US real-world setting. METHODSA prospective, noninterventional, multicenter longitudinal study was conducted in US patients initiating treatment with palbociclib combination therapy for HR + /HER2 - aBC/mBC. PRO data (SF-12; CES-D-10; mood; pain; fatigue; interference of aBC/mBC or its treatment on family life, social life, physical activity, energy, and productivity; overall health rating; and quality of life [QOL]) were collected via a custom-developed mobile application at daily, weekly, and cycle-based intervals. Patient medical information (demographics, clinical characteristics, treatment information, and adverse events) was collected from medical records at baseline and at the end of the 6-month follow-up period. RESULTSPatients' general health status (SF-12) remained consistent throughout treatment and was generally consistent with published norms for individuals diagnosed with cancer. The presence of depression (CES-D-10) was low and did not change substantially over time. Mean pain and fatigue scores using an 11-point numeric rating scale were low and remained stable. Patients, on average, reported neutral or positive moods. Patient-reported QOL and overall health was primarily "Good," "Very good," or "Excellent." Findings were consistent regardless of patient experience with neutropenia. CONCLUSIONSPatients treated with palbociclib, on average, reported consistently low levels of pain and fatigue as well as good QOL and overall health that remained stable throughout the first 6 months of treatment regardless of episodes of neutropenia