Comparing Regional Population Genetic Effects in Leptasterias spp.

Leptasterias spp. is a species complex of six-rayed intertidal sea stars found along the northeast Pacific coast. A developmental mode of brooding their young, rather than broadcasting for planktonic development, limits dispersal away from the natal area, and may also result in local adaptation of populations. Local adaptation may lead to morphological and behavioral differences among populations. Previous studies on behavior in Leptasterias spp. have shown that activity levels may vary by population and region. Across three regions from California to Washington, differences were only observed between central California and more northern regions while northern California, Oregon, and Washington were similar to each other in activity level. Here, we tested whether regions showing similarity in behavioral activity are also genetically similar in clade composition. Mitochondrial DNA barcoding was used to determine species and clade overlap among the two similar regions. DNA was extracted from arm tip and tube feet tissue samples from stars found in intertidal sites from three different regions; Washington, northern California, and central California. Mitochondrial CO1 sequence was obtained from the DNA via PCR and Sanger sequencing at the Estuary and Ocean Science Center, SFSU Genetics Lab to determine whether different species of Leptasterias spp. have different activity levels. Three species level clades of Leptasterias spp. are found in these regions., L. hexactis, L. aequalis, and L. pusilla. Regional differences in clade and species composition were observed between Washington stars and stars from California however, no difference in clade or species composition was observed between northern and central California. Previous behavior studies identified no significant difference in activity level between Washington and northern California stars, yet a significant difference between central California stars in comparison to Washington and northern California. These findings and the corresponding genetic analysis suggest that clade and species composition is not a sole determinant of activity levels in Leptasterias spp

Programming and Design for Dementia: Development of a 50 Person Residential Environment

The monograph describes an applied research project whose goals are: 1) to extend understanding of optimal micro-environmental design for people with dementia; 2) to present a systematic process for the planning, programming and design of environments for people with dementia; and 3) to illustrate this by the planning, programming and design of a model 50-person residential facility. Sponsored by Helen Daniel Bader, Milwaukee.https://dc.uwm.edu/caupr_mono/1014/thumbnail.jp

The everyday food practices of community-dwelling Lesbian, Gay, Bisexual, and Transgender (LGBT) older adults

Malnutrition during old age is a significant public health issue. Prevailing behavioral and structural senior malnutrition interventions have had marginal success, largely failing to reflect the realities of people\u27s daily lives. This novel study employed Social Practice Theory (SPT) to explore the food practices of an under-researched, yet highly vulnerable, segment of the older adult population—Lesbian, Gay, Bisexual, and Transgender (LGBT) seniors. Four focus groups were conducted with 31 older adult clients and volunteers at a national LGBT social service and advocacy organization. Findings revealed that food practices—far from being mere expressions of individuals\u27 choices or immutable habits—are entities composed of meanings, materials, and competences that are structured as they are performed repeatedly in a social context. Gaining insight into how and why diverse older adults perform food practices in light of obstacles common to aging has important implications for senior nutrition program and policy development

Physical processes determine spatial structure in water temperature and residence time on a wide reef flat

Author Posting. © American Geophysical Union, 2020. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Oceans 125(12), (2020): e2020JC016543, https://doi.org/10.1029/2020JC016543.On coral reefs, flow determines residence time of water influencing physical and chemical environments and creating observable microclimates within the reef structure. Understanding the physical mechanisms driving environmental variability on shallow reefs, which distinguishes them from the open ocean, is important for understanding what contributes to thermal resilience of coral communities and predicting their response to future anomalies. In June 2014, a field experiment conducted at Dongsha Atoll in the northern South China Sea investigated the physical forces that drive flow over a broad shallow reef flat. Instrumentation included current and pressure sensors and a distributed temperature sensing system, which resolved spatially and temporally continuous temperature measurements over a 3‐km cross‐reef section from the lagoon to reef crest. Spectral analysis shows that while diurnal variability was significant across the reef flat—a result expected from daily solar heating—temperature also varied at higher frequencies near the reef crest. These spatially variable temperature regimes, or thermal microclimates, are influenced by circulation on the wide reef flat, with spatially and temporally variable contributions from tides, wind, and waves. Through particle tracking simulations, we find the residence time of water is shorter near the reef crest (3.6 h) than near the lagoon (8.6 h). Tidal variability in flow direction on the reef flat leads to patterns in residence time that are different than what would be predicted from unidirectional flow. Circulation on the reef also determines the source (originating from offshore vs. the lagoon) of the water present on the reef flat.We thank S. Tyler, and J. Selker from the Center for Transformative Environmental Monitoring Programs (CTEMPs), funded by the National Science Foundation (EAR awards 1440596 and 1440506), for timely and effective provision of experimental design support, logistical support and equipment for the project. Support for S. Lentz is from NSF Grant No. OCE‐1558343. Support for A. Cohen from NSF Grant No. 1220529, by the Academia Sinica (Taiwan) through a thematic project grant to G. Wong and A. Cohen. Support for E. Reid and K. Davis is from National Science Foundation (NSF) Grant No. OCE‐1753317, and support to E. Reid from the Environmental Engineering Henry Samueli Endowed Fellowship and the UCI Oceans Graduate Fellowship.2021-05-2

Timescale of Stellar Feedback-Driven Turbulence in the ISM: A Deep Dive into UGC 4305

Understanding the interplay of stellar feedback and turbulence in the interstellar medium (ISM) is essential to modeling the evolution of galaxies. To determine the timescales over which stellar feedback drives turbulence in the ISM, we performed a spatially resolved, multi-wavelength study of the nearby star-forming dwarf galaxy UGC 4305 (aka Holmberg II). As indicators of turbulence on local scales (400 pc), we utilized ionized gas velocity dispersion derived from IFU H$\alpha$ observations and atomic gas velocity dispersion and energy surface densities derived from HI synthesis observations with the Very Large Array. These indicators of turbulence were tested against star formation histories over the past 560 Myr derived from Color-Magnitude Diagrams (CMD) using Spearman's rank correlation coefficient. The strongest correlation identified at the 400 pc scale is between measures of HI turbulence and star formation 70-140 Myr ago. We repeated our analysis of UGC 4305's current turbulence and past star formation activity on multiple physical scales ($\sim$560, and 800 pc) to determine if there are indications of changes in the correlation timescale with changes to the physical scale. No notable correlations were found at larger physical scales emphasizing the importance of analyzing star formation driven turbulence as a local phenomenon.Comment: 17 pages, 9 figure, accepted to A

Pegasus W: An Ultra-Faint Dwarf Galaxy Outside the Halo of M31 Not Quenched by Reionization

We report the discovery of an ultrafaint dwarf (UFD) galaxy, Pegasus W, located on the far side of the Milky Way-M31 system and outside the virial radius of M31. The distance to the galaxy is 915 (+60/-91) kpc, measured using the luminosity of horizontal branch (HB) stars identified in Hubble Space Telescope optical imaging. The galaxy has a half-light radius (r_h) of 100 (+11/-13) pc, M_V = -7.20 (+0.17/-0.16) mag, and a present-day stellar mass of 6.5 (+1.1/-1.4) x 10^4 Msun. We identify sources in the color-magnitude diagram (CMD) that may be younger than ~500 Myr suggesting late-time star formation in the UFD galaxy, although further study is needed to confirm these are bona fide young stars in the galaxy. Based on fitting the CMD with stellar evolution libraries, Pegasus W shows an extended star formation history (SFH). Using the tau_90 metric (defined as the timescale by which the galaxy formed 90% of its stellar mass), the galaxy was quenched only 7.4 (+2.2/-2.6) Gyr ago, which is similar to the quenching timescale of a number of UFD satellites of M31 but significantly more recent than the UFD satellites of the Milky Way. Such late-time quenching is inconsistent with the more rapid timescale expected by reionization and suggests that, while not currently a satellite of M31, Pegasus W was nonetheless slowly quenched by environmental processes.Comment: 15 pages, 10 figures, 2 table

Mass coral mortality under local amplification of 2°C ocean warming

© The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Scientific Reports 7 (2017): 44586, doi:10.1038/srep44586.A 2°C increase in global temperature above pre-industrial levels is considered a reasonable target for avoiding the most devastating impacts of anthropogenic climate change. In June 2015, sea surface temperature (SST) of the South China Sea (SCS) increased by 2 °C in response to the developing Pacific El Niño. On its own, this moderate, short-lived warming was unlikely to cause widespread damage to coral reefs in the region, and the coral reef “Bleaching Alert” alarm was not raised. However, on Dongsha Atoll, in the northern SCS, unusually weak winds created low-flow conditions that amplified the 2°C basin-scale anomaly. Water temperatures on the reef flat, normally indistinguishable from open-ocean SST, exceeded 6°C above normal summertime levels. Mass coral bleaching quickly ensued, killing 40% of the resident coral community in an event unprecedented in at least the past 40 years. Our findings highlight the risks of 2°C ocean warming to coral reef ecosystems when global and local processes align to drive intense heating, with devastating consequences.This research was funded by the National Science Foundation (OCE-1031971 and OCE-1605365 to A.L.C), the Sustainability Science Research Program of the Academia Sinica (G.T.F.W. and A.L.C), a Woods Hole Oceanographic Institution Coastal Ocean Institute award to T.M.D., and a National Science Foundation Graduate Research Fellowship awarded to T.M.D

Discovery and Characterization of Two Ultra Faint-Dwarfs Outside the Halo of the Milky Way: Leo M and Leo K

We report the discovery of two ultra-faint dwarf galaxies, Leo M and Leo K, that lie outside the halo of the Milky Way. Using Hubble Space Telescope imaging of the resolved stars, we create color-magnitude diagrams reaching the old main sequence turn-off of each system and (i) fit for structural parameters of the galaxies; (ii) measure their distances using the luminosity of the Horizontal Branch stars; (iii) estimate integrated magnitudes and stellar masses; and (iv) reconstruct the star formation histories. Based on their location in the Local Group, neither galaxy is currently a satellite of the Milky Way, although Leo K is located ~22 kpc from the low-mass galaxy Leo T and these two systems may have had a past interaction. Leo M and Leo K have stellar masses of 1.5+/-0.2 x 10^4 Msun and 1.0+/-0.2 x 10^4 Msun, and were quenched 10.9 (+1.8/-0.6) Gyr and 12.6 (+0.2/-5.8) Gyr ago, respectively. Given that the galaxies are not satellites of the MW, it is unlikely that they were quenched by environmental processing. Instead, such low masses and early quenching timescales are consistent with the scenario that a combination of reionization and stellar feedback shut down star formation at early cosmic times.Comment: 12 pages, 9 figures, 1 tabl

Fate of internal waves on a shallow shelf

Author Posting. © American Geophysical Union, 2020. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Oceans 125(5), (2020): e2019JC015377, doi:10.1029/2019JC015377.Internal waves strongly influence the physical and chemical environment of coastal ecosystems worldwide. We report novel observations from a distributed temperature sensing (DTS) system that tracked the transformation of internal waves from the shelf break to the surf zone over a narrow shelf slope region in the South China Sea. The spatially continuous view of temperature fields provides a perspective of physical processes commonly available only in laboratory settings or numerical models, including internal wave reflection off a natural slope, shoreward transport of dense fluid within trapped cores, and observations of internal rundown (near‐bed, offshore‐directed jets of water preceding a breaking internal wave). Analysis shows that the fate of internal waves on this shelf—whether transmitted into shallow waters or reflected back offshore—is mediated by local water column density structure and background currents set by the previous shoaling internal waves, highlighting the importance of wave‐wave interactions in nearshore internal wave dynamics.We are grateful for the support of the Dongsha Atoll Research Station (DARS) and the Dongsha Atoll Marine National Park, whose efforts made this research possible. The authors would also like to thank A. Hall, S. Tyler, and J. Selker from the Center for Transformative Environmental Monitoring Programs (CTEMPs) funded by the National Science Foundation (EAR awards 1440596 and 1440506), G. Lohmann from WHOI, A. Safaie from UC Irvine, G. Wong, L. Hou, F. Shiah, and K. Lee from Academia Sinica for providing logistical and field support, as well as E. Pawlak, S. Lentz, B. Sanders, and S. Grant for equipment, and B. Raubenheimer, S. Elgar, R. Walter and D. Lucas for informative discussions that improved this work. We acknowledge the US Army Research Laboratory DoD Supercomputing Resource Center for computer time on Excalibur, which was used for the numerical simulations in this work. Funding for this work supported by Academia Sinica and for K.D. and E.R. from NSF‐OCE 1753317 and for O.F., J.R., and R.A. from ONR Grant 1182789‐1‐TDZZM. A portion of this work (R.A.) was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE‐AC52‐07NA27344.2020-10-2