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The kelp, Ecklonia radiata, is an abundant subtidal ecosystem engineer in southern Australia. Density-dependent changes in the abiotic environment engineered by Ecklonia may feedback to affect reproduction and subsequent recruitment. Here, we examined: 1) how the reproductive capacity of Ecklonia individuals in the field (zoospores released · mm-2 reproductive tissue) varied with adult density and time, and 2) how the recruitment of microscopic gametophytes and sporophytes was influenced by zoospore density at two times. Zoospore production did not vary with adult density, with only one month out of ten sampled over a 2-y period showing a significant effect of density. However, zoospore production varied hugely over time, being generally highest in mid-autumn and lowest in mid-late summer. There were strong effects of initial zoospore density on gametophyte and sporophyte recruitment with both a minimum and an optimum zoospore density for sporophyte recruitment, but these varied in time. Almost no sporophytes developed when initial zoospore density was 335 · mm-2 in spring and >261 · mm-2 in winter and was zero at very high zoospore densities. These findings suggest that although adult Ecklonia density does not affect per-capita zoospore production, because there is a minimum zoospore density for sporophyte production, a decline in population-level output could feedback to impact recruitment.

New and unique opportunities now exist to look for technosignatures (TS) beyond traditional SETI radio searches, motivated by tremendous advances in exoplanet science and observing capabilities in recent years. Space agencies, both public and private, may be particularly interested in learning about the community's views as to the optimal methods for future TS searches with current or forthcoming technology. This report is an effort in that direction. We put forward a set of possible mission concepts designed to search for TS, although the data supplied by such missions would also benefit other areas of astrophysics. We introduce a novel framework to analyze a broad diversity of TS in a quantitative manner. This framework is based on the concept of ichnoscale, which is a new parameter related to the scale of a TS cosmic footprint, together with the number of potential targets where such TS can be searched for, and whether or not it is continuous in time., Accepted for publication in Acta Astronautica

Highlights: • First study to compare microplastic effects over a wide biogeographical range • Comparison between natural inorganic microparticles and plastic microparticles • Significant effects on byssus production, respiration and clearance rates, but small effect sizes • No ecologically relevant difference between impact of plastic and natural inorganic microparticles on Mytilidae Abstract: Microplastics are ubiquitous in the marine environment and studies on their effects on benthic filter feeders at least partly revealed a negative influence. However, it is still unclear whether the effects of microplastics differ from those of natural suspended microparticles, which constitute a common stressor in many coastal environments. We present a series of experiments that compared the effects of six-week exposures of marine mussels to two types of natural particles (red clay and diatom shells) to two types of plastic particles (Polymethyl Methacrylate and Polyvinyl Chloride). Mussels of the family Mytilidae from temperate regions (Japan, Chile, Tasmania) through subtropical (Israel) to tropical environments (Cabo Verde) were exposed to concentrations of 1.5 mg/L, 15 mg/L and 150 mg/L of the respective microparticles. At the end of this period, we found significant effects of suspended particles on respiration rate, byssus production and condition index of the animals. There was no significant effect on clearance rate and survival. Surprisingly, we observed only small differences between the effects of the different types of particles, which suggests that the mussels were generally equally robust towards exposure to variable concentrations of suspended solids regardless of whether they were natural or plastic. We conclude, that microplastics and suspended solids elicit similar effects on the tested response variables, and that both types of microparticles mainly cause acute responses rather than more persistent carry-over effects.

Author(s): Teton, Ben Scott | Advisor(s): Young, Hillary S | Abstract: Estimating population abundance through time is an essential component of wildlife conservation and management. However, accurate population monitoring can be difficult and expensive for many elusive species occurring across large, dynamic landscapes. Thus, wildlife managers require methods that accurately estimate population abundance, while also minimizing field effort and cost. We estimated abundance of invasive wild pigs (Sus scrofa) on Tejon Ranch in the Tehachapi Mountains of California, using natural markings to identify individuals for mark-resight population estimation. Wild pigs in this region, like many species not traditionally identified using natural marks, are generally homogeneous in appearance with distinctive features that range dramatically in relative visibility, uniqueness and permanence. We developed a method based on standardized thresholds of image quality and animal flank distinctiveness to account for the inherent variability of natural markings between individuals. This method was tested over a fifteen-month period between March 2015 and June 2016, using an array of 48 camera traps across a 48km² survey grid. With 18.5% of wild pigs meeting our conservative standard of identifiability, we generated absolute estimates of abundance across five consecutive three-month sampling periods using the Poisson log-normal estimator under Pollocks robust design. Using left-flank photos of both naturally marked and unmarked pigs, we generated abundance estimates ranging from 352 (SE + 56) individuals in summer 2015 to 157 (SE + 43) individuals in spring 2016. These results suggest an overall decline in the wild pig population on Tejon Ranch from 2015 to 2016, which is supported by a simultaneous decline in Ranch-wide hunter harvest totals during this period. As this mark-resight method requires no trapping or tagging of any kind, it may be utilized as a cost and resource efficient alternative to traditional mark-resight techniques that rely on ear-tags or neck-bands for individual identification of species traditionally considered unidentifiable using natural marks alone.

The hot Jupiter HD 217107 b was one of the first exoplanets detected using the radial velocity (RV) method, originally reported in the literature in 1999. Today, precise RV measurements of this system span more than 20 years, and there is clear evidence for a longer-period companion, HD 217107 c. Interestingly, both the short-period planet ($P_\mathrm{b}\sim7.13$ d) and long-period planet ($P_\mathrm{c}\sim5059$ d) have significantly eccentric orbits ($e_\mathrm{b}\sim0.13$ and $e_\mathrm{c}\sim0.40$). We present 42 additional RV measurements of this system obtained with the MINERVA telescope array and carry out a joint analysis with previously published RV measurements from four different facilities. We confirm and refine the previously reported orbit of the long-period companion. HD 217107 b is one of a relatively small number of hot Jupiters with an eccentric orbit, opening up the possibility of detecting precession of the planetary orbit due to General Relativistic effects and perturbations from other planets in the system. In this case, the argument of periastron, $\omega$, is predicted to change at the level of $\sim$0.8$^\circ$ century$^{-1}$. Despite the long time baseline of our observations and the high quality of the RV measurements, we are only able to constrain the precession to be $\dot{\omega}, Comment: 8 pages, 3 figures, accepted for publication in Astronomische Nachrichten

In SETI, when searching for "beacons" -- transmissions intended for us and meant to get our attention -- one must guess the appropriate frequency to search by considering what frequencies would be universally obvious to other species. This is a well known concept in game theory, where such solutions to a non-communicative cooperative game (such as a mutual search) are called "Schelling points." It is noteworthy, therefore, that when developing his eponymous units, Planck called them "natural" because they "remain meaningful for all times and also for extraterrestrial and non-human cultures." Here, I apply Planck's suggestion in the context of Schelling points in SETI with a "Planck Frequency Comb," constructed by multiplying the Planck energy by integer powers of the fine structure constant. This comb includes a small number of frequencies in regions of the electromagnetic spectrum where laser and radio SETI typically operates. Searches might proceed and individual teeth in the comb, or at many teeth at once, across the electromagnetic spectrum. Indeed, the latter strategy can be additionally justified by the transmitter's desire to signal at many frequencies at once, to improve the chances that the receiver will guess one of them correctly. There are many arbitrary and anthropocentric choices in this comb's construction, and indeed one can construct several different frequency combs with only minor and arbitrary modifications. This suggests that it may be fruitful to search for signals arriving in frequency combs of arbitrary spacing. And even though the frequencies suggested here are only debatably "better" than others proposed, the addition of the Planck Frequency Comb to the list of "magic frequencies" can only help searches for extraterrestrial beacons., Comment: 14 tables, 5 tables, accepted to the International Journal of Astrobiology. v4. Has minor language corrections and a correction to equations 5 and 7, and proper number of significant figures in the tables. v5. adds a relevant reference

Kelp forests in many regions are experiencing disturbance from anthropogenic sources such as ocean warming, pollution, and overgrazing. Unlike natural disturbances such as storms, anthropogenic disturbances often manifest as press perturbations that cause persistent alterations to the environment. One consequence is that some kelp forests are becoming increasingly sparse and fragmented. We manipulated patch size of the kelp Ecklonia radiata over 24 mo to simulate persistent habitat fragmentation and assessed how this influenced the demography of macro- and microscopic juvenile kelp within the patches. At the beginning of the experiment, patch formation resulted in short-term increases in E. radiata recruitment in patches 2. However, recruitment collapsed in those same patches over the extended period, with no recruits observed after 15 mo. Experimental transplants of microscopic and macroscopic juvenile sporophytes into the patches failed to identify the life stage impacted by the reductions in patch size, indicating that the effects may be subtle and require extended periods to manifest, and/or that another life stage is responsible. Abiotic measurements within the patches indicated that kelp were less able to engineer the sub-canopy environment in smaller patches. In particular, reduced shading of the sub-canopy in smaller patches was associated with proliferation of sediments and turf algae, which potentially contributed to the collapse of recruitment. We demonstrate the consequences of short- and longer-term degradation of E. radiata habitats and conclude that habitat fragmentation can lead to severe disruptions to kelp demography.

Patterns of abundance and shell morphology of intertidal gastropods are typically thought to depend on environmental conditions, but ecosystem engineers such as canopy-forming seaweeds can also influence these traits. The intertidal seaweed Hormosira banksii (H. banksii) is an abundant species and important ecosystem engineer on rocky shores and estuaries in south-east Australia, where it creates thick canopies colonized by a range of invertebrates, particularly gastropods. In Tasmania (southern Australia), H. banksii shows large variability in thallus length and structure, with different algal morphologies on coasts and in estuaries. In this study, individuals of two gastropod species were sampled from different habitats (north coast, east coast and northern estuaries) to: (1) describe the spatial variability in their abundance and shell morphology, and (2) understand if any relationship exists between H. banksii morphology and gastropod shell morphology. Gastropod abundance and morphology were variable, but multivariate analysis suggested a marginal influence of H. banksii morphological traits, particularly vesicle size, on the patterns observed. As the two gastropod species use habitat differently and that different H. banksii morphs occur in different locations, our results suggest that both algal morphology and environmental conditions may affect gastropod abundance and shell morphology across the different habitats. Hence, from these results a model can be developed and tested in subsequent experimental work to tease apart the effects of seaweed morphology from environmental conditions.

Habitat‐forming ecosystem engineers are the foundation of many marine ecosystems where they support diverse and productive food‐webs. A reduction in their patch size or density may affect the productivity, biodiversity and stability of these ecosystems. We determined the effects of different densities and patch sizes of Ecklonia radiata (the dominant kelp in southern Australia) on the secondary productivity, species richness, diversity and community structure of understory epifaunal invertebrates and how associated environmental covariates modified by kelp affected those patterns. We assessed sub‐canopy epifauna across 28 artificial reefs with transplanted E. radiata consisting of seven different patch sizes (0.12–7.68 m2) crossed with four kelp densities (0–16 kelp m−2) over two years. Epifaunal secondary productivity associated with both natural algal and standardised rope fibre habitats decreased with patch size and was elevated when kelp was absent, however, it was also high in natural habitat when there was a high density of kelp. Epifaunal productivity was positively associated with sub‐canopy light and water flow but negatively associated with the biomass of the dominant understory alga, Ulva sp. Epifaunal diversity declined with a reduction in reef size as did richness which correlated with a loss of algal species richness. Community structure of epifauna also differed between small and large reefs, between reefs with and without kelp, between rope habitats at the centre and at the edge of reefs, and within natural habitat between reefs supporting high and low densities of kelp. Overall, these results indicate complex effects of E. radiata decline on epifaunal communities, with high secondary productivity associated with dense kelp stands, but also areas without kelp that are dominated by turf algae. While the loss of standing kelp from rocky reefs may result in declines in epifaunal biodiversity, where turf algae replaces kelp, the reefs may still support high secondary productivity.

Ecosystem engineers are important in shaping the composition of associated communities, including the abundance of species which exert additional influences on the ecosystem. Using an array of 28 artificial reefs supporting transplants of a dominant canopy-forming kelp (Ecklonia radiata) representing 7 patch sizes (0.12-7.68 m2) crossed with 4 kelp densities (0-16 ind. m-2), we determined how differences in the patch size and density of this ecosystem engineer influenced the associated understorey assemblages, including the abundance of turf algae, foliose algae and sessile invertebrates. We then determined how abiotic and biotic factors modified by E. radiata related to the abundance of these functional groups and E. radiata recruitment. Decreasing patch size and absence of kelp led to the proliferation of turfs, whilst foliose algae and invertebrates were dominant on larger reefs with kelp, where intermediate densities of kelp supported the highest abundance of foliose algae. We postulate that benthic light was the most important factor positively influencing turf cover, which in turn suppressed foliose algae. Adverse effects of light and sediment deposition best explained the cover of invertebrates. Contrary to expectation, understorey species had little effect on the density of E. radiata recruits, which instead was strongly correlated with the abundance of transplanted kelp on each reef. These results highlight the capacity of E. radiata to influence major functional groups within the sub-canopy via abiotic ecosystem engineering and through control of turfs and indicate that the negative effect of understorey algae on kelp recruitment may be context specific.

At the Fermilab Tevatron proton-antiproton ($p\bar{p}$) collider, high-mass electron-neutrino ($e\nu$) pairs are produced predominantly in the process $p \bar{p} \rightarrow W(\rightarrow e\nu) + X$. The asymmetry of the electron and positron yield as a function of their pseudorapidity constrain the slope of the ratio of the $u$- to $d$-quark parton distributions versus the fraction of the proton momentum carried by the quarks. This paper reports on the measurement of the electron-charge asymmetry using the full data set recorded by the Collider Detector at Fermilab in 2001--2011 and corresponding to 9.1~fb$^{-1}$ of integrated luminosity. The measurement significantly improves the precision of the Tevatron constraints on the parton-distribution functions of the proton. Numerical tables of the measurement are provided.

We present a high-precision radial velocity (RV) survey of 719 FGKM stars, which host 164 known exoplanets and 14 newly discovered or revised exoplanets and substellar companions. This catalog updated the orbital parameters of known exoplanets and long-period candidates, some of which have decades-longer observational baselines than they did upon initial detection. The newly discovered exoplanets range from warm sub-Neptunes and super-Earths to cold gas giants. We present the catalog sample selection criteria, as well as over 100,000 radial velocity measurements, which come from the Keck-HIRES, APF-Levy, and Lick-Hamilton spectrographs. We introduce the new RV search pipeline RVSearch that we used to generate our planet catalog, and we make it available to the public as an open-source Python package. This paper is the first study in a planned series that will measure exoplanet occurrence rates and compare exoplanet populations, including studies of giant planet occurrence beyond the water ice line, and eccentricity distributions to explore giant planet formation pathways. We have made public all radial velocities and associated data that we use in this catalog., Accepted to ApJS

Introduced predators currently threaten endemic animals on Madagascar through predation, facilitation of human-led hunts, competition, and disease transmission, but the antiquity and past consequences of these introductions are poorly known. We use directly radiocarbon dated bones of introduced dogs (Canis familiaris) to test whether dogs could have aided human-led hunts of the island’s extinct megafauna. We compare carbon and nitrogen isotope data from the bone collagen of dogs and endemic “fosa” (Cryptoprocta spp.) in central and southwestern Madagascar to test for competition between introduced and endemic predators. The distinct isotopic niches of dogs and fosa suggest that any past antagonistic relationship between these predators did not follow from predation or competition for shared prey. Radiocarbon dates confirm that dogs have been present on Madagascar for over a millennium and suggest that they at least briefly co-occurred with the island’s extinct megafauna, which included giant lemurs, elephant birds, and pygmy hippopotamuses. Today, dogs share a mutualism with pastoralists who also occasionally hunt endemic vertebrates, and similar behavior is reflected in deposits at several Malagasy paleontological sites that contain dog and livestock bones along with butchered bones of extinct megafauna and extant lemurs. Dogs on Madagascar have had a wide range of diets during the past millennium, but relatively high stable carbon isotope values suggest few individuals relied primarily on forest bushmeat. Our newly generated data suggest that dogs were part of a suite of animal introductions beginning over a millennium ago that coincided with widespread landscape transformation and megafaunal extinction. Introduction Materials and Methods - Specimen and Site Selection - 14C and Stable Isotope Analyses - Data Analysis Results - Chronological Data - Stable Isotope Data Discussion

Ecosystem engineers are species that influence the abiotic and biotic environment around them and may assist the restoration of associated species, including other habitat‐forming species. We deployed an array of 28 artificial reefs with transplanted Ecklonia radiata, the dominant canopy‐forming kelp species across southern Australia, to investigate how the patch size and density of E. radiata influenced the establishment of the associated communities of plants and animals. Many of the reefs were rapidly colonized by Ostrea angasi, a critically depleted reef‐forming oyster. Over the 24‐month deployment of the reefs, thick oyster mats formed across the entire surface of many of the reefs with estimated biomass densities exceeding 5 kg of live oysters/m2; however, oyster density was dependent on E. radiata patch size and density. Increasing patch size and the presence of kelp resulted in significantly higher densities of oysters 5 months after the reefs were deployed and at the end of the experiment, where oysters were approximately three times more numerous on reefs with kelp compared to those without kelp. E. radiata appeared to facilitate the establishment of O. angasi largely through its capacity to reduce benthic light and thus suppress competition from turfing algae. These results may inform the development of novel approaches to tackle recruitment bottlenecks affecting the restoration of O. angasi reefs.

Due to concerns over the effects of oil production activities on groundwater quality in California, chemical, isotopic, dissolved gas and age-dating tracers were analyzed in samples collected from public-supply wells and produced-water sites in the Fruitvale oil field (FVOF). A combination of newly collected and historical data was used to determine whether oil formation fluids have mixed with groundwater used for public supply and what the potential pathways for the migration of oil formation fluids into groundwater may be. Stable isotopes of water (δ2H and δ18O) and age dating (3H, 3Hetrit, SF6 and 14C) tracers in groundwater samples were consistent with the Kern River being the main source of recharge to aquifers. The distribution of major ion concentrations and pH with distance from the Kern River indicate that natural processes were the primary controls on groundwater salinity. Two of 14 groundwater samples had δ13C-DIC values (−2.4 to +1.9 per mil) consistent with mixtures of

The Yiluo region in the middle Yellow River has been a core area of archaeological inquiry for understanding the origins of the first dynastic states in China. In order to investigate the social changes on a regional scale, a systematic full-coverage regional survey project was carried out from 1997 to 2018, covering an area of 1183 km2 in the Yiluo region. This paper analyzes the settlement patterns of 451 sites of the Neolithic and Bronze Ages (ca. 6000–200 cal. BC), providing the most comprehensive pictures yet, of the spatial and temporal relationships of settlement distribution during a nearly 6000-year time span. The paper demonstrates a developmental trajectory from a landscape dotted with scattered, small Neolithic villages to a highly centralized dynastic heartland in early Chinese civilization. The evolutionary pathways were not straightforward, but were characterized by episodic fluctuations in population density, and the rise and fall of complex societies. Holocene climatic fluctuations may have played significant roles affecting human activities, but it is the human responses to external challenges in various ways that ultimately determined the trajectories of social evolution.

Climate change is characterised by multiple abiotic forcings acting simultaneously on biotic systems. In marine systems, temperature appears to drive much of the observed change in biotic communities subject to climate change, but this may reflect the focus of most studies only on temperature without consideration of other environmental variables affected by climate change. The giant kelp Macrocystis pyrifera was once abundant in eastern Tasmania, forming extensive habitats of ecological and economic importance, but recent extensive population decline has occurred. Southerly incursion of warm oligotrophic East Australian Current (EAC) water has increased in frequency and intensity into this region, which has warmed ~4 times the global average, and the warming trend is predicted to continue. This study investigated the single and combined effects of temperature, light, and nitrate availability on the physiology of juvenile M. pyrifera sporophytes in a laboratory experiment. Determination of relative growth rate, photosystem II characteristics, pigments, elemental chemistry, and nucleic acid characteristics over 28 d showed that all experimental factors affected sporeling physiology. Temperature and light drove much of the observed variation related to performance characteristics, and rapid deterioration of kelp tissue was a consequence of temperature stress (high temperature), photoinhibition (high light), and low light, accompanied by impaired photosynthetic efficiency and increased RNA concentration, presumably associated with production of photoprotective proteins. Surprisingly, higher relative growth rates were observed in low-nitrate treatments. These findings suggest that negative effects of temperature on M. pyrifera populations will be mediated by local variation in light and nutrient conditions.

Boyajian's star is an apparently normal main sequence F-type star with a very unusual light curve. The dipping activity of the star, discovered during the Kepler mission, presents deep, asymmetric, and aperiodic events. Here we present high resolution spectroscopic follow-up during some dimming events recorded post-Kepler observations, from ground-based telescopes. We analise data from the HERMES, HARPS-N and FIES spectrographs to characterise the stellar atmosphere and to put some constraints on the hypotheses that have appeared in the literature concerning the occulting elements. The star's magnetism, if existing, is not extreme. The spots on the surface, if present, would occupy 0.02% of the area, at most. The chromosphere, irrespective of the epoch of observation, is hotter than the values expected from radiative equilibrium, meaning that the star has some degree of activity. We find no clear evidence of the interstellar medium nor exocoments being responsible for the dimmings of the light curve. However, we detect at 1-2 sigma level, a decrease of the radial velocity of the star during the first dip recorded after the \emph{\emph{Kepler}} observations. We claim the presence of an optically thick object with likely inclined and high impact parameter orbits that produces the observed Rossiter-McLaughlin effect., Comment: submitted to MNRAS

Kelp forests around the world are under increasing pressure from anthropogenic stressors. A widespread consequence is that in many places, complex and highly productive kelp habitats have been replaced by structurally simple and less productive turf algae habitats. Turf algae habitats resist re‐establishment of kelp via recruitment inhibition; however, little is known about the specific mechanisms involved. One potential factor is the chemical environment within the turf algae and into which kelp propagules settle and develop. Using laboratory trials, we illustrate that the chemical microenvironment (O2 concentration and pH) 0.0–50 mm above the substratum within four multispecies macroalgal assemblages (including a turf‐sediment assemblage and an Ecklonia radiata kelp‐dominated assemblage) are characterized by elevated O2 and pH relative to the surrounding seawater. Notably however, O2 and pH were significantly higher within turf‐sediment assemblages than in kelp‐dominated assemblages, and at levels that have previously been demonstrated to impair the photosynthetic or physiological capacity of kelp propagules. Field observations of the experimental assemblages confirmed that recruitment of kelp was significantly lower into treatments with dense turf algae than in the kelp‐dominated assemblages. We demonstrate differences between the chemical microenvironments of kelp and turf algae assemblages that correlate with differences in kelp recruitment, highlighting how degradation of kelp habitats might result in the persistence of turf algae habitats and the localized absence of kelp.

We used high-precision radial velocity measurements of FGKM stars to determine the occurrence of giant planets as a function of orbital separation spanning 0.03-30 au. Giant planets are more prevalent at orbital distances of 1-10 au compared to orbits interior or exterior of this range. The increase in planet occurrence at $\sim$1 au by a factor of $\sim$4 is highly statistically significant. A fall-off in giant planet occurrence at larger orbital distances is favored over models with flat or increasing occurrence. We measure $14.1^{+2.0}_{-1.8}$ giant planets per 100 stars with semi-major axes of 2-8 au and $8.9^{+3.0}_{-2.4}$ giant planets per 100 stars in the range 8-32 au, a decrease in giant planet occurrence with increasing orbital separation that is significant at the $\sim$2$\sigma$ level. We find that the occurrence rate of sub-Jovian planets (0.1-1 Jupiter masses) is also enhanced for 1-10 au orbits. This suggests that lower mass planets may share the formation or migration mechanisms that drive the increased prevalence near the water-ice line for their Jovian counterparts. Our measurements of cold gas giant occurrence are consistent with the latest results from direct imaging surveys and gravitational lensing surveys despite different stellar samples. We corroborate previous findings that giant planet occurrence increases with stellar mass and metallicity., Comment: accepted to ApJS

To contribute to achieving local and global sustainability, we propose a novel educational methodology, called field environmental philosophy (FEP), which orients ecotourism practices to reconnect citizens and nature. FEP is based on the systemic approach of the biocultural ethic that values the vital links among the life habits of co-inhabitants (humans and other-than-humans) who share a common habitat. Based on this “3Hs” model (habitats, co-inhabitants, habits), FEP combines tourism with experiential education to reorient biocultural homogenization toward biocultural conservation. FEP’s methodological approach seeks to integrate social, economic, and environmental dimensions of sustainability by generating new links between biological and cultural diversity at different spatial and social scales. Ecotourism has an underutilized potential to link sciences with education and conservation practices at different scales. By incorporating a philosophical foundation, FEP broadens both understanding and practices of environmental education and sustainable tourism. FEP has been developed at the Omora Ethnobotanical Park in the Cape Horn Biosphere Reserve, Chile, at the southern end of the Americas since 2000, where it has oriented transdisciplinary work for the creation of new protected areas and ecotourism practices. FEP enables an integration of biophysical, cultural, and institutional dimensions into the design of ecotourism activities that transform and broaden the perceptions of tourists, local guides, students, and other participants to better appreciate local biological and cultural diversity. FEP’s methodology is starting to be adapted in other world regions, such as Germany, Japan, and Mexico, to integrate education and ecotourism for sustainability.

The Habitable zone Planet Finder (HPF) is a fiber fed precise radial velocity spectrograph at the 10 m Hobby Eberly Telescope (HET). Due to its fixed altitude design, the HET pupil changes appreciably across a track, leading to significant changes of the fiber far-field illumination. HPF's fiber scrambler is designed to suppress the impact of these illumination changes on the radial velocities -- but the residual impact on the radial velocity measurements has yet to be probed on sky. We use GJ 411, a bright early type (M2) M dwarf to probe the effects of far-field input trends due to these pupil variations on HPF radial velocities (RVs). These large changes ($\sim$ 2x) in pupil area and centroid present a harsh test of HPF's far-field scrambling. Our results show that the RVs are effectively decoupled from these extreme far-field input changes due to pupil centroid offsets, attesting to the effectiveness of the scrambler design. This experiment allows us to test the impact of these changes with large pupil variation on-sky, something we would not easily be able to do at a conventional optical telescope. While the pupil and illumination changes expected at these other telescopes are small, scaling from our results enables us to estimate and bound these effects, and show that they are controllable even for the new and next generation of RV instruments in their quest to beat down instrumental noise sources towards the goal of a few cm/s., 16 pages. Published in The Astrophysical Journal

NEID is a high-resolution optical spectrograph on the WIYN 3.5-m telescope at Kitt Peak National Observatory and will soon join the new generation of extreme precision radial velocity instruments in operation around the world. We plan to use the instrument to conduct the NEID Earth Twin Survey (NETS) over the course of the next 5 years, collecting hundreds of observations of some of the nearest and brightest stars in an effort to probe the regime of Earth-mass exoplanets. Even if we take advantage of the extreme instrumental precision conferred by NEID, it will remain difficult to disentangle the weak (~10 cm s$^{-1}$) signals induced by such low-mass, long-period exoplanets from stellar noise for all but the quietest host stars. In this work, we present a set of quantitative selection metrics which we use to identify an initial NETS target list consisting of stars conducive to the detection of exoplanets in the regime of interest. We also outline a set of observing strategies with which we aim to mitigate uncertainty contributions from intrinsic stellar variability and other sources of noise., 19 pages, 10 figures, 1 table

The human colonization of eastern Africa's near- and offshore islands was accompanied by the translocation of several domestic, wild and commensal fauna, many of which had long-term impacts on local environments. To better understand the timing and nature of the introduction of domesticated caprines (sheep and goat) to these islands, this study applied collagen peptide fingerprinting (Zooarchaeology by Mass Spectrometry or ZooMS) to archaeological remains from eight Iron Age sites, dating between ca 300 and 1000 CE, in the Zanzibar, Mafia and Comoros archipelagos. Where previous zooarchaeological analyses had identified caprine remains at four of these sites, this study identified goat at seven sites and sheep at three, demonstrating that caprines were more widespread than previously known. The ZooMS results support an introduction of goats to island eastern Africa from at least the seventh century CE, while sheep in our sample arrived one–two centuries later. Goats may have been preferred because, as browsers, they were better adapted to the islands' environments. The results allow for a more accurate understanding of early caprine husbandry in the study region and provide a critical archaeological baseline for examining the potential long-term impacts of translocated fauna on island ecologies. 1. Introduction 2. Background 2.1. Island colonization and species translocations 2.2. Tracing the introduction of caprines to insular Eastern Africa 3. Methods 3.1. Sites 3.2. Sample selection 3.3. ZooMS protocol 3.3.1. Acid-insoluble protocol 3.3.2. Acid-soluble protocol 3.3.3. Lyophilized collagen for stable isotope analysis 3.3.4. C18 clean-up and MALDI-ToF analysis 4. Results 5. Discussion 5.1. Diachronic patterns in the introduction of caprines 5.2. Island herd compositions 5.3. Wild faunal extirpations and translocations 5.4. Long-term ecological impacts of caprines on Eastern Africa’s islands 6. Conclusion

Canopy-forming macroalgae form the basis of diverse coastal ecosystems globally. The fucoid Hormosira banksii is often the dominant canopy-forming macroalga in the temperate intertidal of southern Australia and New Zealand, where it is commonly associated with an understory of coralline turf. Hormosira banksii is susceptible to both natural and anthropogenic disturbance and despite its abundance, few studies have examined the demography of this important species. This study determined the demographic response of H. banksii to different gradients of disturbance to both its canopy and to the understory coralline turf. We established plots in which the density of H. banksii and/or understory coralline turf was manipulated in a pulse perturbation to simulate a disturbance event. The manipulated plots contained eight treatments ranging from 100% removal of H. banksii to 100% removal of the understory coralline turf. We then measured recruitment and followed individual recruits for up to 18 months to determine growth and survivorship. We found that H. banksii recruitment was seasonally variable throughout the experiment and highest over summer, survivorship of recruits was generally high, and the species was slow-growing and long-lived. Moreover, the level of disturbance did not seem to affect recruitment, growth, or survivorship and post-recruitment mortality was independent of H. banksii density. In this system, it appears that H. banksii is a relatively long-lived perennial species whose demography is density-independent which appears to allow recovery from disturbance.

We present the discovery of \thisstar\ (HD 58730), a very low mass ratio ($q \equiv M_2/M_1 \approx 0.07$) eclipsing binary (EB) identified by the Kilodegree Extremely Little Telescope (KELT) survey. We present the discovery light curve and perform a global analysis of four high-precision ground-based light curves, the Transiting Exoplanets Survey Satellite (TESS) light curve, radial velocity (RV) measurements, Doppler Tomography (DT) measurements, and the broad-band spectral energy distribution (SED). Results from the global analysis are consistent with a fully convective ($M_2 = 0.22 \pm 0.02\ M_{\odot})$ M star transiting a late-B primary ($M_1 = 3.34^{+0.07}_{-0.09}\ M_{\odot};\ T_{\rm eff,1} = 11960^{+430}_{-520}\ {\rm K}$). We infer that the primary star is $183_{-30}^{+33}$ Myr old and that the companion star's radius is inflated by $26 \pm 8\%$ relative to the predicted value from a low-mass isochrone of similar age. We separately and analytically fit for the variability in the out-of-eclipse TESS phase curve, finding good agreement between the resulting stellar parameters and those from the global fit. Such systems are valuable for testing theories of binary star formation and understanding how the environment of a star in a close-but-detached binary affects its physical properties. In particular, we examine how a star's properties in such a binary might differ from the properties it would have in isolation., Comment: 19 pages, 12 figures, accepted to MNRAS

Microbial bile salt hydrolases (BSHs) found in the intestine catalyze the deconjugation of taurine- and glycine-linked bile salts produced in the liver. The resulting bile salts are biological detergents and are critical in aiding lipophilic nutrient digestion. Therefore, the activity of BSHs in the gut microbiome is directly linked to human metabolism and overall health. Bile salt metabolism has also been associated with disease phenotypes such as liver and colorectal cancer. In order to reshape the gut microbiome to optimize bile salt metabolism, tools to characterize and quantify these processes must exist to enable a much-improved understanding of how metabolism goes awry in the face of disease, and how it can be improved through an altered lifestyle and environment. Furthermore, it is necessary to attribute metabolic activity to specific members and BSHs within the microbiome. To this end, we have developed activity-based probes with two different reactive groups to target bile salt hydrolases. These probes bind similarly to the authentic bile salt substrates, and we demonstrate enzyme labeling of active bile salt hydrolases by using purified protein, cell lysates, and in human stool.

Background Although intensive blood pressure (BP)-lowering treatment reduces risk for cardiovascular disease, there are concerns that it might cause orthostatic hypotension (OH). Purpose To examine the effects of intensive BP-lowering treatment on OH in hypertensive adults. Data sources MEDLINE, EMBASE, and Cochrane CENTRAL from inception through 7 October 2019, without language restrictions. Study selection Randomized trials of BP pharmacologic treatment (more intensive BP goal or active agent) that involved more than 500 adults with hypertension or elevated BP and that were 6 months or longer in duration. Trial comparisons were groups assigned to either less intensive BP goals or placebo, and the outcome was measured OH, defined as a decrease of 20 mm Hg or more in systolic BP or 10 mm Hg or more in diastolic BP after changing position from seated to standing. Data extraction 2 investigators independently abstracted articles and rated risk of bias. Data synthesis 5 trials examined BP treatment goals, and 4 examined active agents versus placebo. Trials examining BP treatment goals included 18 466 participants with 127 882 follow-up visits. Trials were open-label, with minimal heterogeneity of effects across trials. Intensive BP treatment lowered risk for OH (odds ratio, 0.93 [95% CI, 0.86 to 0.99]). Effects did not differ by prerandomization OH (P for interaction = 0.80). In sensitivity analyses that included 4 additional placebo-controlled trials, overall and subgroup findings were unchanged. Limitations Assessments of OH were done while participants were seated (not supine) and did not include the first minute after standing. Data on falls and syncope were not available. Conclusion Intensive BP-lowering treatment decreases risk for OH. Orthostatic hypotension, before or in the setting of more intensive BP treatment, should not be viewed as a reason to avoid or de-escalate treatment for hypertension. Primary funding source National Heart, Lung, and Blood Institute, National Institutes of Health. (PROSPERO: CRD42020153753).

Using radial-velocity data from the Habitable-zone Planet Finder, we have measured the mass of the Neptune-sized planet K2-25b, as well as the obliquity of its M4.5-dwarf host star in the 600-800MYr Hyades cluster. This is one of the youngest planetary systems for which both of these quantities have been measured, and one of the very few M dwarfs with a measured obliquity. Based on a joint analysis of the radial velocity data, time-series photometry from the K2 mission, and new transit light curves obtained with diffuser-assisted photometry, the planet's radius and mass are $3.44\pm 0.12 \mathrm{R_\oplus}$ and $24.5_{-5.2}^{+5.7} \mathrm{M_\oplus}$. These properties are compatible with a rocky core enshrouded by a thin hydrogen-helium atmosphere (5% by mass). We measure an orbital eccentricity of $e=0.43 \pm 0.05$. The sky-projected stellar obliquity is $\lambda=3 \pm 16^{\circ}$, compatible with spin-orbit alignment, in contrast to other "hot Neptunes" that have been studied around older stars., Comment: Accepted for publication in AJ, 31 pages, 14 figures

Highlights: • Mussel BCI was 14% lower after exposure to PVC particles in comparison to red clay. • Byssus production, respiration and survival did not differ between particle types. • Mussels suffered little from the five-week particle exposure up to 150 mg l−1. Abstract: Effects of microplastics on marine taxa have become a focal point in marine experimental biology. Almost all studies so far, however, assessed the influence of microplastics on animals only in relation to a zero-particle group. Documented microplastic impacts may thus be overestimated, since many marine species also experience natural suspended solids as a stressor. Here, we compared the effects of polyvinyl chloride (PVC) and red clay (mean for both particles: ~12–14 μm) on the Mediterranean mussel Mytilus galloprovincialis across three particle concentrations (1.5, 15, 150 mg l−1). Exposure to PVC for 35 days lowered mussel body condition index by 14% in relation to clay, but no difference in byssus production, respiration and survival rates emerged between the two particle types. This suggests that the effects of synthetic particles on filter feeders may emulate those of natural suspended solids, and highlights the importance of including natural particles in microplastic exposure studies.

We confirm the planetary nature of a warm Jupiter transiting the early M dwarf TOI-1899, using a combination of available TESS photometry; high-precision, near-infrared spectroscopy with the Habitable-zone Planet Finder; and speckle and adaptive optics imaging. The data reveal a transiting companion on an $\sim29$-day orbit with a mass and radius of $0.66\pm0.07\ \mathrm{M_{J}}$ and $1.15_{-0.05}^{+0.04}\ \mathrm{R_{J}}$, respectively. The star TOI-1899 is the lowest-mass star known to host a transiting warm Jupiter, and we discuss the follow-up opportunities afforded by a warm ($\mathrm{T_{eq}}\sim362$ K) gas giant orbiting an M0 star. Our observations reveal that TOI-1899.01 is a puffy warm Jupiter, and we suggest additional transit observations to both refine the orbit and constrain the true dilution observed in TESS., 24 pages, 5 figures, 3 tables, published in AJ

Animals produce bile to act as an antibacterial agent and to maximize the absorption of lipophilic nutrients in the gut. The physical properties of bile are largely dictated by amphipathic bile salt molecules, which also participate in signaling pathways by modulating physiological processes upon binding host receptors. Upon excretion of bile salts from the gall bladder into the intestine, the gut microbiota can create metabolites with modified signaling capabilities. The category and magnitude of bile salt metabolism can have positive or negative effects on the host. A key modification is bile salt hydrolysis, which is a prerequisite for all additional microbial transformations. We have synthesized five different fluorogenic bile salts for simple and continuous reporting of hydrolysis in both murine and human fecal samples. Our data demonstrate that most gut microbiomes have the highest capacity for hydrolysis of host-produced primary bile salts, but some microbially modified secondary bile salts also display significant turnover.

As foundation species, kelp support productive and species rich communities; however, the effects of kelp structure on mobile species within these complex natural systems are often difficult to assess. We used artificial reefs with transplanted kelp to quantify the influence of kelp patch size and density on fish assemblages including the arrival of recruiting cryptobenthic species. Large patches with dense kelp supported the highest abundance, species richness, and diversity of fishes, with the addition of dense kelp tripling biomass and doubling richness. The abundance of recruits in artificial collectors declined with patch size and was halved on reefs with sparse kelp compared to reefs with dense kelp or no kelp. These results highlight the importance of dense kelp cover in facilitating biodiversity and indicate that kelp addition could support the recovery of degraded coastal ecosystems. Kelp also apparently drives complex interactions affecting the recruitment/behaviour of some cryptobenthic species.

The isotope used in this research was supplied by the United States Department of Energy Office of Science by the Isotope Program in the Office of Nuclear Physics., The neutron capture cross section of 154Gd was measured from 1 eV to 300 keV in the experimental area located 185 m from the CERN n_TOF neutron spallation source, using a metallic sample of gadolinium, enriched to 67% in 154Gd. The capture measurement, performed with four C6D6 scintillation detectors, has been complemented by a transmission measurement performed at the GELINA time-of-flight facility (JRC-Geel), thus minimising the uncertainty related to sample composition. An accurate Maxwellian averaged capture cross section (MACS) was deduced over the temperature range of interest for s process nucleosynthesis modelling. We report a value of 880(50) mb for the MACS at kT = 30 keV, significantly lower compared to values available in literature. The new adopted 154Gd(n,γ ) cross section reduces the discrepancy between observed and calculated solar s-only isotopic abundances predicted by s-process nucleosynthesis models., EUFRAT open access programme of the Joint Research Centre at Geel

In a companion paper, we have conducted an in-depth analysis of radial velocity jitter of over 600 stars, examining the astrophysical origins including stellar granulation, oscillation, and magnetic activity. In this paper, we highlight a subsample of those stars, specifically the main sequence and "retired" F stars -- which we refer to as "MSRF" stars -- that show low levels of RV jitter ($, 10 pages, 8 figures, published in The Astronomical Journal

Solar contamination, due to moonlight and atmospheric scattering of sunlight, can cause systematic errors in stellar radial velocity (RV) measurements that significantly detract from the ~10 cm s−1 sensitivity required for the detection and characterization of terrestrial exoplanets in or near habitable zones of Sun-like stars. The addition of low-level spectral contamination at variable effective velocity offsets introduces systematic noise when measuring velocities using classical mask-based or template-based cross-correlation techniques. Here we present simulations estimating the range of RV measurement error induced by uncorrected scattered sunlight contamination. We explore potential correction techniques, using both simultaneous spectrometer sky fibers and broadband imaging via coherent fiber imaging bundles, that could reliably reduce this source of error to below the photon-noise limit of typical stellar observations. We discuss the limitations of these simulations, the underlying assumptions, and mitigation mechanisms. We also present and discuss the components designed and built into the NEID (NN-EXPLORE Exoplanet Investigations with Doppler spectroscopy) precision RV instrument for the WIYN 3.5 m telescope, to serve as an ongoing resource for the community to explore and evaluate correction techniques. We emphasize that while "bright time" has been traditionally adequate for RV science, the goal of 10 cm s−1 precision on the most interesting exoplanetary systems may necessitate access to darker skies for these next-generation instruments.

In the measurement of neutron capture cross-sections of fissile isotopes, the fission channel is a source of background which can be removed efficiently using the so-called fission-tagging or fission-veto technique. For this purpose a new compact and fast fission chamber has been developed. The design criteria and technical description of the chamber are given within the context of a measurement of the 233U(n, ������) cross-section at the n_TOF facility at CERN, where it was coupled to the n_TOF Total Absorption Calorimeter. For this measurement the fission detector was optimized for time resolution, minimization of material in the neutron beam and for alpha-fission discrimination. The performance of the fission chamber and its application as a fission tagging detector are discussed., This work was partially supported by the French NEEDS/NACRE Project and by the European Commission within HORIZON2020 via the EURATOM Project EUFRAT.

A new fossil site in a previously unexplored part of western Madagascar (the Beanka Protected Area) has yielded remains of many recently extinct vertebrates, including giant lemurs (Babakotia radofilai, Palaeopropithecus kelyus, Pachylemur sp., and Archaeolemur edwardsi), carnivores (Cryptoprocta spelea), the aardvark-like Plesiorycteropus sp., and giant ground cuckoos (Coua). Many of these represent considerable range extensions. Extant species that were extirpated from the region (e.g., Prolemur simus) are also present. Calibrated radiocarbon ages for 10 bones from extinct primates span the last three millennia. The largely undisturbed taphonomy of bone deposits supports the interpretation that many specimens fell in from a rock ledge above the entrance. Some primates and other mammals may have been prey items of avian predators, but human predation is also evident. Strontium isotope ratios (87Sr/86Sr) suggest that fossils were local to the area. Pottery sherds and bones of extinct and extant vertebrates with cut and chop marks indicate human activity in previous centuries. Scarcity of charcoal and human artifacts suggests only occasional visitation to the site by humans. The fossil assemblage from this site is unusual in that, while it contains many sloth lemurs, it lacks ratites, hippopotami, and crocodiles typical of nearly all other Holocene subfossil sites on Madagascar., Research at Beanka was supported by the National Geographic Society via Waitt Foundation grants W263-13 and W388-15 to DAB, and by the site-managing organization, Biodiversity Conservation Madagascar (BCM). EJdB was supported by a travel grant from the Society for Advancement of Research in the Tropics (Treub Maatschappij). The scientific study authorization was provided by the Bureau du Cadastre Minier de Madagascar with the reference 024/2015. Many thanks to faculty of the Université d'Antananarivo and staff of BCM and Association Vahatra for assistance with permits and logistics. To the staff of BCM and the people of the village of Ambinda, we extend special thanks for hospitality and assistance with fieldwork and information regarding sites and access. Bone specimens were identified from studies of comparative materials at the Field Museum of Natural History, the Université d'Antananarivo, Association Vahatra, Duke Lemur Center, Muséum national d'Histoire naturelle (Paris), the Natural History Museum (London), the Smithsonian Institution, the American Museum of Natural History, and the University of Massachusetts, Amherst. Species identifications were supported in part by NSF BCS-1750598 (to LRG). Isotopic and radiocarbon analyses were supported in part by NSF BCS-1749676 (to BEC).

We validate the discovery of a 2 Earth radii sub-Neptune-size planet around the nearby high proper motion M2.5-dwarf G 9-40 (EPIC 212048748), using high-precision near-infrared (NIR) radial velocity (RV) observations with the Habitable-zone Planet Finder (HPF), precision diffuser-assisted ground-based photometry with a custom narrow-band photometric filter, and adaptive optics imaging. At a distance of $d=27.9\mathrm{pc}$, G 9-40b is the second closest transiting planet discovered by K2 to date. The planet's large transit depth ($\sim$3500ppm), combined with the proximity and brightness of the host star at NIR wavelengths (J=10, K=9.2) makes G 9-40b one of the most favorable sub-Neptune-sized planet orbiting an M-dwarf for transmission spectroscopy with JWST, ARIEL, and the upcoming Extremely Large Telescopes. The star is relatively inactive with a rotation period of $\sim$29 days determined from the K2 photometry. To estimate spectroscopic stellar parameters, we describe our implementation of an empirical spectral matching algorithm using the high-resolution NIR HPF spectra. Using this algorithm, we obtain an effective temperature of $T_{\mathrm{eff}}=3404\pm73$K, and metallicity of $\mathrm{[Fe/H]}=-0.08\pm0.13$. Our RVs, when coupled with the orbital parameters derived from the transit photometry, exclude planet masses above $11.7 M_\oplus$ with 99.7% confidence assuming a circular orbit. From its radius, we predict a mass of $M=5.0^{+3.8}_{-1.9} M_\oplus$ and an RV semi-amplitude of $K=4.1^{+3.1}_{-1.6}\mathrm{m\:s^{-1}}$, making its mass measurable with current RV facilities. We urge further RV follow-up observations to precisely measure its mass, to enable precise transmission spectroscopic measurements in the future., Comment: Accepted for publication in AJ, 22 pages, 15 figures

The idea of slow-neutron capture nucleosynthesis formulated in 1957 triggered a tremendous experimental effort in different laboratories worldwide to measure the relevant nuclear physics input quantities, namely (n, γ) cross sections over the stellar temperature range (from few eV up to several hundred keV) for most of the isotopes involved from Fe up to Bi. A brief historical review focused on total energy detectors will be presented to illustrate how advances in instrumentation have led to the assessment of new aspects of s-process nucleosynthesis and to the progressive refinement of stellar models. A summary will be presented on current efforts to develop new detection concepts, such as the Total-Energy Detector with γ-ray imaging capability (i-TED). The latter is based on the simultaneous combination of Compton imaging with neutron time-of-flight (TOF) techniques, in order to achieve a superior level of sensitivity and selectivity in the measurement of stellar neutron capture rates., European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (ERC Consolidator Grant project HYMNS) 681740, Instituto de Salud Carlos III Spanish Government FPA2014-52823-C2-1-P FPA2017-83946-C2-1-P, Consejo Superior de Investigaciones Cientificas (CSIC) PIE-201750I26, Program Severo Ochoa SEV-2014-0398

Native habitat-forming species can facilitate invasion by reducing environmental stress or consumer pressure. However, the intensity of one stressor along a local gradient may differ when expanding the scale of observation to encompass major variations in background environmental conditions. In this study, we determined how facilitation of the invasive porcelain crab, Petrolisthes elongatus, by the native tube-forming serpulid, Galeolaria caespitosa, varied with environmental gradients at local (tidal height) and larger (wave exposure) spatial scales. G. caespitosa constructs a complex calcareous matrix on the underside of intertidal boulders and we predicted that its positive effects on P. elongatus density would increase in intensity with shore height and be stronger at wave-sheltered than wave-exposed locations. To test these predictions, we conducted two experiments. First, we determined the effects of serpulid presence (boulders with live or dead serpulid matrix vs. bare boulders) at six shore heights that covered the intertidal distribution of P. elongatus. Second, we determined the effects of serpulid presence (present vs. absent), shore height (high vs. low) and wave exposure (sheltered vs. exposed) on crabs across six locations within the invaded range in northern Tasmania, Australia. In Experiment 1, the presence of serpulids (either dead or alive) enhanced P. elongatus densities at all shore heights, with facilitation intensity (as determined by a relative interaction index; RII) tending to increase with shore height. In Experiment 2, serpulids facilitated P. elongatus across shore heights and wave exposures, although crab densities were lower at high shore levels of wave-sheltered locations. However, the intensity of crab facilitation by serpulids was greater on wave-sheltered than on wave-exposed shores, but only at the high shore level. This study demonstrates that local effects of native habitat-formers on invasive species are dependent on prevailing environmental conditions at larger spatial scales and that, under more stressful conditions, invaders become increasingly reliant on positive interactions with native habitat-formers. Increased strength of local-scale facilitation by native species, dampening broader scale variations in environmental stressors, could enhance the ability of invasive species to establish self-sustaining populations in the invaded range.

Young, rapidly-rotating M dwarfs exhibit prominent starspots, which create quasiperiodic signals in their photometric and Doppler spectroscopic measurements. The periodic Doppler signals can mimic radial velocity (RV) changes expected from orbiting exoplanets. Exoplanets can be distinguished from activity-induced false positives by the chromaticity and long-term incoherence of starspot signals, but these qualities are poorly constrained for fully-convective M stars. Coherent photometric starspot signals on M dwarfs may persist for hundreds of rotations, and the wavelength dependence of starspot RV signals may not be consistent between stars due to differences in their magnetic fields and active regions. We obtained precise multi-wavelength RVs of four rapidly-rotating M dwarfs (AD Leo, G 227-22, GJ 1245B, GJ 3959) using the near-infrared (NIR) Habitable-zone Planet Finder, and the optical Keck/HIRES spectrometer. Our RVs are complemented by photometry from Kepler, TESS, and the Las Cumbres Observatory (LCO) network of telescopes. We found that all four stars exhibit large spot-induced Doppler signals at their rotation periods, and investigated the longevity and optical-to-NIR chromaticity for these signals. The phase curves remain coherent much longer than is typical for Sunlike stars. Their chromaticity varies, and one star (GJ 3959) exhibits optical and NIR RV modulation consistent in both phase and amplitude. In general, though, we find that the NIR amplitudes are lower than their optical counterparts. We conclude that starspot modulation for rapidly-rotating M stars frequently remains coherent for hundreds of stellar rotations, and gives rise to Doppler signals that, due to this coherence, may be mistaken for exoplanets., Comment: Accepted for publication in the Astrophysical Journal

Some of the most scientifically valuable transiting planets are those that were already known from radial velocity (RV) surveys. This is primarily because their orbits are well characterized and they preferentially orbit bright stars that are the targets of RV surveys. The Transiting Exoplanet Survey Satellite ({\it TESS}) provides an opportunity to survey most of the known exoplanet systems in a systematic fashion to detect possible transits of their planets. HD~136352 (Nu$^2$~Lupi) is a naked-eye ($V = 5.78$) G-type main-sequence star that was discovered to host three planets with orbital periods of 11.6, 27.6, and 108.1 days via RV monitoring with the HARPS spectrograph. We present the detection and characterization of transits for the two inner planets of the HD~136352 system, revealing radii of $1.482^{+0.058}_{-0.056}$~$R_\oplus$ and $2.608^{+0.078}_{-0.077}$~$R_\oplus$ for planets b and c, respectively. We combine new HARPS observations with RV data from Keck/HIRES and the AAT, along with {\it TESS} photometry from Sector 12, to perform a complete analysis of the system parameters. The combined data analysis results in extracted bulk density values of $\rho_b = 7.8^{+1.2}_{-1.1}$~gcm$^{-3}$ and $\rho_c = 3.50^{+0.41}_{-0.36}$~gcm$^{-3}$ for planets b and c, respectively, thus placing them on either side of the radius valley. The combination of the multi-transiting planet system, the bright host star, and the diversity of planetary interiors and atmospheres means this will likely become a cornerstone system for atmospheric and orbital characterization of small worlds., Comment: 13 pages, 4 figures, 3 tables, accepted for publication in the Astronomical Journal

Future exoplanet direct imaging missions, such as HabEx and LUVOIR, will select target stars to maximize the number of Earth-like exoplanets that can have their atmospheric compositions characterized. Because one of these missions’ aims is to detect biosignatures, they should also consider the expected biosignature yield of planets around these stars. In this work, we develop a method of computing relative biosignature yields among potential target stars, given a model of habitability and biosignature genesis, and using a star’s habitability history. As an illustration and first application of this method, we use MESA stellar models to calculate the time evolution of the habitable zone and examine three simple models for biosignature genesis to calculate the relative biosignature yield for different stars. We find that the relative merits of K stars versus F stars depend sensitively on model choice. In particular, use of the present-day habitable zone as a proxy for biosignature detectability favors young, luminous stars lacking the potential for long-term habitability. Biosignature yields are also sensitive to whether life can arise on Cold Start exoplanets that enter the habitable zone after formation, an open question deserving of more attention. Using the case study of biosignature yields calculated for θ Cygni and 55 Cancri, we find that robust mission design and target selection for HabEx and LUVOIR depend on choosing a specific model of biosignature appearance with time, the terrestrial planet occurrence rate as a function of orbital separation, precise knowledge of stellar properties, and accurate stellar evolutionary histories.

Ecosystem engineers are predicted to have stronger facilitative effects when environmental stress is higher. Here we examined whether facilitation of the invasive porcelain crab Petrolisthes elongatus by the ecosystem engineering serpulid tube worm Galeolaria caespitosa increased with wave exposure. Petrolisthes occurs beneath intertidal boulders which often have a high cover of Galeolaria on their underside. Surveys across nine sites demonstrated Petrolisthes abundance beneath boulders increased with wave exposure and Galeolaria cover, although only when the habitat matrix beneath boulders was rock or mixed rock and sand. Moreover, as wave exposure increased, the strength of relationship between Petrolisthes abundance and the surface area of Galeolaria also increased. Experimentally, the presence of Galeolaria on the underside of boulders increased Petrolisthes abundance by 50% compared to boulders lacking Galeolaria. Our findings suggest the facilitative role of Galeolaria is stronger at more wave-exposed sites, which appears to contribute to a higher abundance of invasive Petrolisthes.

DHF gratefully acknowledges support from the ECOGAL project, grant agreement 291227, funded by the European Research Council under ERC-2011-ADG. The Center for Exoplanets and Habitable Worlds is supported by the Pennsylvania State University, the Eberly College of Science, and the Pennsylvania Space Grant Consortium. The Rio scale is a tool for communicating the significance of a signal to the general public. It assigns scores to signals detected in searches for extraterrestrial intelligence (SETI), which characterizes both the consequences of a signal and the probability the signal is truly from ETI, in an easily digestible format for laypeople to interpret. In the 17 years since its construction, the number of groups actively conducting searches for evidence of intelligent life beyond the Earth has increased significantly, and theoretical work has established a new suite of observables that are capable of revealing the presence of ETI in a range of astronomical observations. In this paper, we revise the Rio scale, with the aim of (i) achieving consensus across academic disciplines on a scheme for classifying signals potentially indicating the existence of advanced extraterrestrial life, (ii) supplying a pedagogical tool to help inform the public about the process scientists go through to develop an understanding of a signal and (iii) providing a means of calibrating the expectations of the world at large when signals are discussed in the media. We also present (and encourage the SETI community to adopt) a single set of consistent terminology for discussing signals. Postprint

By comparing the Zhou state-building narrative from textual sources with patterns observed in our archaeological survey in the Qufu region, our collaborative research project investigates the role of place memory in the creation or renewal of urban tradition in the Zhou society of the early first millennium BCE. Our study of the regional archaeological landscape as a palimpsest identified evidence for field system associated with the establishment of a Zhou colony at the turn of the first millennium BCE and its transformation from a military stronghold to a full-blown Eastern Zhou urban center during the late first millennium BCE. We conclude that the Zhou political rhetoric of settling on the ruins of past regimes allowed the architects of Zhou state to tap into the emplaced social memory shared by the diverse memory communities in its vast territory. A shared social memory about an important episode from the past contributed an enduring aura to the Chinese urban landscape, and thus deserves to be studied as a central component of urban history in early China.

Thin 33S samples for the study of the 33S(n, α)30Si cross-section at the n_TOF facility at CERN were made by thermal evaporation of 33S powder onto a dedicated substrate made of kapton covered with thin layers of copper, chromium and titanium. This method has provided for the first time bare sulfur samples a few centimeters in diameter. The samples have shown an excellent adherence with no mass loss after few years and no sublimation in vacuum at room temperature. The determination of the mass thickness of 33S has been performed by means of Rutherford backscattering spectrometry. The samples have been successfully tested under neutron irradiation.