On the stellar kinematics and mass of the Virgo ultradiffuse galaxy VCC 1287

Here, we present a kinematical analysis of the Virgo cluster ultradiffuse galaxy (UDG) VCC 1287 based on data taken with the Keck Cosmic Web Imager (KCWI). We confirm VCC 1287's association both with the Virgo cluster and its globular cluster (GC) system, measuring a recessional velocity of 1116 ± 2 km s-1. We measure a stellar velocity dispersion (19 ± 6 km s-1) and infer both a dynamical mass ($1.11^{+0.81}_{-0.81} \times 10^{9} \ \mathrm{M_{\odot }}$) and mass-To-light ratio (M/L) ($13^{+11}_{-11}$) within the half-light radius (4.4 kpc). This places VCC 1287 slightly above the well-established relation for normal galaxies, with a higher M/L for its dynamical mass than normal galaxies. We use our dynamical mass, and an estimate of GC system richness, to place VCC 1287 on the GC number-dynamical mass relation, finding good agreement with a sample of normal galaxies. Based on a total halo mass derived from GC counts, we then infer that VCC 1287 likely resides in a cored or low-concentration dark matter halo. Based on the comparison of our measurements to predictions from simulations, we find that strong stellar feedback and/or tidal effects are plausibly the dominant mechanisms in the formation of VCC 1287. Finally, we compare our measurement of the dynamical mass with those for other UDGs. These dynamical mass estimates suggest relatively massive haloes and a failed galaxy origin for at least some UDGs.The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Maunakea has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain. We thank the staff of the W. M. Keck Observatory for their assistance in using the telescope and wish to express particular gratitude to Luca Rizzi in helping us fix issues that presented themselves. We have also made heavy use of a number of open source packages in the creation of this work. We therefore wish to thank contributors to ASTROPY (Price-Whelan et al. 2018), SCIPY (Virtanen et al. 2020), SCIKIT–LEARN (Pedregosa et al. 2011), NUMPY (Oliphant 2019), SEABORN (Waskom et al. 2017), CORNER (Foreman-Mackey 2016), and EMCEE (Foreman-Mackey et al. 2013) for making their software publicly available. JSG acknowledges financial support received through a Swinburne University Postgraduate Research Award throughout the creation of this work. AFM has received financial support through the Post-doctoral Junior Leader Fellowship Programme from ‘La Caixa’ Banking Foundation (LCF/BQ/LI18/11630007). AJR was supported by National Science Foundation grant AST-1616710, and as a Research Corporation for Science Advancement Cottrell Scholar. JPB gratefully acknowledges support from National Science foundation grants AST-1518294 and AST-1616598

Herbicide-Resistance in Turf Systems: Insights and Options for Managing Complexity

Due to complex interactions between social and ecological systems, herbicide resistance has classic features of a “wicked problem.” Herbicide-resistant (HR) Poa annua poses a risk to sustainably managing U.S. turfgrass systems, but there is scant knowledge to guide its management. Six focus groups were conducted throughout the United States to gain understanding of socio-economic barriers to adopting herbicide-resistance management practices. Professionals from major turfgrass sectors (golf courses, sports fields, lawn care, and seed/sod production) were recruited as focus-group participants. Discussions emphasized challenges of the weed management of turfgrass systems as compared to agronomic crops. This included greater time constraints for managing weeds and more limited chemical control options. Lack of understanding about the proper use of compounds with different modes of action was identified as a threat to sustainable weed management. There were significant regional differences in perceptions of the existence, geographic scope, and social and ecological causes of HR in managing Poa annua. Effective resistance management will require tailoring chemical and non-chemical practices to the specific conditions of different turfgrass sectors and regions. Some participants thought it would be helpful to have multi-year resistance management programs that are both sector- and species-specific. © 2022 by the authors.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

The (b)old and the beautiful : investigating the preference of senior consumers concerning (the age of) models used in advertising

Today, it is estimated that 7.6 per cent of the world population is aged over 65 (CIA, 2009), making it the fastest-growing age segment in the world. Considering that older citizens do not only grow in number, but also in life expectancy and economic power, one would expect the elderly to receive a great amount of attention from advertisers. But even though marketing executives are aware of the importance of senior consumers, older models are rarely used in mainstream advertising. When they appear in advertisements, elderly are primarily depicted in a negative, stereotypical way (Gunter, 1998; Sikkel, 2004). Older models are mainly found in ads for ‘senior products’ like health products, often suggesting some form of physical impairment. However, these cliché images are far from the current reality. Today’s seniors are socially active, living an active and dynamic life. They are also a powerful consumer group with the means and the willingness to try out new things (Hanson, 1998). Nevertheless, almost no models older than 50 can be found in advertisements for general, age-universal products. This underrepresentation and stereotyping evokes feelings of dissatisfaction, frustration and even insult (Dutta-Bergman, 2006). Many older consumers become alienated from and disinterested in advertisements because they do not identify with the models used in advertisements. These emotions can negatively influence seniors’ attitudes towards advertising (and brands) and affect their purchase intention. While a series of studies revealed that older consumers would like to see more models of their own age in ads (e.g. Long, 1998), other research suggests that seniors do not wish to be confronted more models of their age group in advertisements (Greco, 1989; Carrigan and Szmigin, 1999). Therefore, the main question addressed in this study is: do senior consumers prefer seeing models of their own age, models who match their subjective age, or even younger models in advertising