Different carboxyl-rich alicyclic molecules proxy compounds select distinct bacterioplankton for oxidation of dissolved organic matter in the mesopelagic Sargasso Sea

© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Liu, S., Parsons, R., Opalk, K., Baetge, N., Giovannoni, S., Bolanos, L. M., Kujawinski, E. B., Longnecker, K., Lu, Y., Halewood, E., & Carlson, C. A. Different carboxyl-rich alicyclic molecules proxy compounds select distinct bacterioplankton for oxidation of dissolved organic matter in the mesopelagic Sargasso Sea. Limnology and Oceanography, (2020), doi:10.1002/lno.11405.Marine dissolved organic matter (DOM) varies in its recalcitrance to rapid microbial degradation. DOM of varying recalcitrance can be exported from the ocean surface to depth by subduction or convective mixing and oxidized over months to decades in deeper seawater. Carboxyl‐rich alicyclic molecules (CRAM) are characterized as a major component of recalcitrant DOM throughout the oceanic water column. The oxidation of CRAM‐like compounds may depend on specific bacterioplankton lineages with oxidative enzymes capable of catabolizing complex molecular structures like long‐chain aliphatics, cyclic alkanes, and carboxylic acids. To investigate the interaction between bacteria and CRAM‐like compounds, we conducted microbial remineralization experiments using several compounds rich in carboxyl groups and/or alicyclic rings, including deoxycholate, humic acid, lignin, and benzoic acid, as proxies for CRAM. Mesopelagic seawater (200 m) from the northwest Sargasso Sea was used as media and inoculum and incubated over 28 d. All amendments demonstrated significant DOC removal (2–11 μmol C L−1) compared to controls. Bacterioplankton abundance increased significantly in the deoxycholate and benzoic acid treatments relative to controls, with fast‐growing Spongiibacteracea, Euryarcheaota, and slow‐growing SAR11 enriched in the deoxycholate treatment and fast‐growing Alteromonas, Euryarcheaota, and Thaumarcheaota enriched in the benzoic acid treatment. In contrast, bacterioplankton grew slower in the lignin and humic acid treatments, with oligotrophic SAR202 becoming significantly enriched in the lignin treatment. Our results indicate that the character of the CRAM proxy compounds resulted in distinct bacterioplankton removal rates of DOM and affected specific lineages of bacterioplankton capable of responding.We thank Z. Landry for the inspiring idea of SAR202 catabolism of CRAM. We thank the University of California, Santa Barbara Marine Science Institute Analytical Laboratory for analyzing inorganic nutrient samples. We thank C. Johnson for her help in FISH sample processing and BATS group in supporting our project. We thank N. K. Rubin‐Saika and R. Padula for their help with amino acid sample preparation. We thank Z. Liu, J. Xue, K. Lu, and Y. Shen for their help with amino acid protocol development and validation. We thank B. Stephens for his help on microscopic image analysis. We thank M. Dasenko and the staff of the CGRB at Oregon State University for amplicon library preparation and DNA sequencing. We are grateful for the help provided by the officers and crews of the R/V Atlantic Explorer. Bermuda Institute of Ocean Sciences (BIOS) provides us tremendous support in terms of facilities and lab space. We thank Bermuda government for its allowance of our water sampling and sample export (export permit number SP160904, issued 07 October 2016 under the Fisheries Act, 1972). This project was supported by Simons Foundation International's BIOS‐SCOPE program

Individual Differences in Cognitive Constructs: A Comparison Between American and Chinese Culture Groups

Previous studies on human cognition show that people with different cultural backgrounds may differ in various ways. However, there are other unexplored possibilities for cultural differences including degree of handedness thought to reflect hemispheric coordination, reliance on verbal versus visual representation in problem solving, and working memory capacity both spatial and operational. We assessed each of these using the Edinburgh scale, a validated scale of style of processing, and two automatic working memory span tasks. Participants were either native Chinese students (who spoke Mandarin) or American students. Data showed that culture impacted the set of measures but gender did not and these factors did not interact. Chinese and American students showed the largest difference in their operational working memory. We also examined the pattern of correlations among the measures across the two groups and found differences due to cultural group as well

Micro-scale pedestrian streetscapes and physical activity in Hispanic / Latino adults : Results from HCHS / SOL

We examined associations of micro-scale environment attributes (e.g., sidewalks, street crossings) with three physical activity (PA) measures among Hispanic/Latino adults (n = 1776) living in San Diego County, CA. Systematic observation was used to quantify micro-scale environment attributes near each participant's home. Total PA was assessed with accelerometers, and PA for transportation and recreation were assessed by validated self-report. Although several statistically significant interactions between individual and neighborhood characteristics were identified, there was little evidence micro-scale attributes were related to PA. An important limitation was restricted environmental variability for this sample which lived in a small area of a single county

Linkages among dissolved organic matter export, dissolved metabolites, and associated microbial community structure response in the northwestern Sargasso Sea on a seasonal scale

© The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Liu, S., Longnecker, K., Kujawinski, E., Vergin, K., Bolaños, L., Giovannoni, S., Parsons, R., Opalk, K., Halewood, E., Hansell, D., Johnson, R., Curry, R., & Carlson, C. Linkages among dissolved organic matter export, dissolved metabolites, and associated microbial community structure response in the northwestern Sargasso Sea on a seasonal scale. Frontiers in Microbiology, 13, (2022): 833252, https://doi.org/10.3389/fmicb.2022.833252.Deep convective mixing of dissolved and suspended organic matter from the surface to depth can represent an important export pathway of the biological carbon pump. The seasonally oligotrophic Sargasso Sea experiences annual winter convective mixing to as deep as 300 m, providing a unique model system to examine dissolved organic matter (DOM) export and its subsequent compositional transformation by microbial oxidation. We analyzed biogeochemical and microbial parameters collected from the northwestern Sargasso Sea, including bulk dissolved organic carbon (DOC), total dissolved amino acids (TDAA), dissolved metabolites, bacterial abundance and production, and bacterial community structure, to assess the fate and compositional transformation of DOM by microbes on a seasonal time-scale in 2016–2017. DOM dynamics at the Bermuda Atlantic Time-series Study site followed a general annual trend of DOC accumulation in the surface during stratified periods followed by downward flux during winter convective mixing. Changes in the amino acid concentrations and compositions provide useful indices of diagenetic alteration of DOM. TDAA concentrations and degradation indices increased in the mesopelagic zone during mixing, indicating the export of a relatively less diagenetically altered (i.e., more labile) DOM. During periods of deep mixing, a unique subset of dissolved metabolites, such as amino acids, vitamins, and benzoic acids, was produced or lost. DOM export and compositional change were accompanied by mesopelagic bacterial growth and response of specific bacterial lineages in the SAR11, SAR202, and SAR86 clades, Acidimicrobiales, and Flavobacteria, during and shortly following deep mixing. Complementary DOM biogeochemistry and microbial measurements revealed seasonal changes in DOM composition and diagenetic state, highlighting microbial alteration of the quantity and quality of DOM in the ocean.This project was funded by the Simons Foundation International’s BIOS-SCOPE program and US National Science Foundation (NSF OCE-1756105 for BATS cruises)

Patterns of Sedentary Time in the Hispanic Community Health Study/Study of Latinos (HCHS/SOL) Youth

Accepted author manuscript version reprinted, by permission, from Journal of Physical Activity and Health, 2020, 18(1), 61-69, https://doi.org/10.1123/jpah.2020-0135. © Human Kinetics, Inc.Background: Total sedentary time and prolonged sedentary patterns can negatively impact health. This study investigated rates of various sedentary pattern variables in Hispanic/Latino youth. Methods: Participants were 956 youths (50.9% female) in the Hispanic Community Health Study/Study of Latinos Youth, a population-based cohort study of Hispanic/Latino 8- to 16-year-olds from 4 geographic regions in the United States (2012–2014). Total sedentary time and 10 sedentary pattern variables were measured through 1 week of accelerometer wear. Differences were examined by sociodemographic characteristics, geographic location, weekdays versus weekends, and season. Results: On average, youth were sedentary during 67.3% of their accelerometer wear time, spent 24.2% engaged in 10- to 29-minute sedentary bouts, and 7.2% in ≥60-minute bouts. 8- to 12-year-olds had more favorable sedentary patterns (less time in extended bouts and more breaks) than 13- to 16-year-olds across all sedentary variables. Sedentary patterns also differed by Hispanic/Latino background, with few differences across sex, household income, season, and place of birth, and none between weekdays versus weekends. Conclusions: Variables representing prolonged sedentary time were high among Hispanic/Latino youth. Adolescents in this group appear to be at especially high risk for unhealthy sedentary patterns. Population-based efforts are needed to prevent youth from engaging in increasingly prolonged sedentary patterns

Neighborhood environment and metabolic risk in Hispanics/Latinos from the Hispanic community health study/study of Latinos

Introduction This study examines the associations of neighborhood environments with BMI, HbA1c, and diabetes across 6 years in Hispanic/Latino adults. Methods Participants from the Hispanic Community Health Study/Study of Latinos San Diego site (n=3,851, mean age=39.4 years, 53.3% women, 94.0% Mexican heritage) underwent assessment of metabolic risk factors and diabetes status (categorized as normoglycemia, prediabetes, and diabetes) at baseline (2008–2011) and approximately 6 years later (2014–2017). In the Study of Latinos Community and Surrounding Areas Study ancillary study (2015–2020), participant baseline addresses were geocoded, and neighborhoods were defined using 800-meter circular buffers. Neighborhood variables representing socioeconomic deprivation, residential stability, social disorder, walkability, and greenness were created using Census and other public databases. Analyses were conducted in 2020–2021. Results Complex survey regression analyses revealed that greater neighborhood socioeconomic deprivation was associated with higher BMI (β=0.14, p<0.001) and HbA1c (β=0.08, p<0.01) levels and a higher odds of worse diabetes status (i.e., having prediabetes versus normoglycemia and having diabetes versus prediabetes; OR=1.25, 95% CI=1.06, 1.47) at baseline. Greater baseline neighborhood deprivation also was related to increasing BMI (β=0.05, p<0.01) and worsening diabetes (OR=1.27, 95% CI=1.10, 1.46) statuses, whereas social disorder was related to increasing BMI levels (β=0.05, p<0.05) at Visit 2. There were no associations of expected protective factors of walkability, greenness, or residential stability. Conclusions Neighborhood deprivation and disorder were related to worse metabolic health in San Diego Hispanic/Latino adults of mostly Mexican heritage. Multilevel interventions emphasizing individual and structural determinants may be most effective in improving metabolic health among Hispanic/Latino individuals

A Panchromatic View OF NGC 602: Time-Resolved Star Formation with the Hubble and Spitzer Space Telescopes

We present the photometric catalogs for the star-forming cluster NGC 602 in the wing of the Small Magellanic Cloud covering a range of wavelengths from optical HST/ACS (F555W, F814W) and SMARTS/ANDICAM (V, I) to infrared (Spitzer/IRAC 3.6, 4.5, 5.8, and 8 micron and MIPS 24 micron). Combining this with IRSF (InfraRed Survey Facility) near-infrared photometry (J, H, Ks), we compare the young main sequence (MS) and pre-main sequence (PMS) populations prominent in the optical with the current young stellar object (YSO) populations revealed by the infrared (IR). We analyze the MS and PMS population with isochrones in color-magnitude diagrams to derive ages and masses. The optical data reveal ~565 PMS candidates, low mass Stage III YSOs. We characterize ~40 YSOs by fitting their spectral energy distributions (SEDs) to a grid of models (Robitaille et al. 2007) to derive luminosities, masses and evolutionary phase (Stage I-III). The higher resolution HST images reveal that ~70% of the YSO candidates are either multiples or protoclusters. For YSOs and PMS sources found in common, we find a consistency in the masses derived. We use the YSO mass function to derive a present-day star-formation rate of ~0.2-1.0 Msun/yr/kpc^2, similar to the rate derived from the optical star formation history suggesting a constant star formation rate for this region. We demonstrate a progression of star formation from the optical star cluster center to the edge of the star forming dust cloud. We derive lifetimes of a few 10^5 years for the YSO Stages I and II.Comment: 55 pages, 18 Figures; High resolution images available form author Accepted to Ap

Invader removal triggers competitive release in a threatened avian predator

Changes in the distribution and abundance of invasive species can have far-reaching ecological consequences. Programs to control invaders are common but gauging the effectiveness of such programs using carefully controlled, large-scale field experiments is rare, especially at higher trophic levels. Experimental manipulations coupled with long-term demographic monitoring can reveal the mechanistic underpinnings of interspecific competition among apex predators and suggest mitigation options for invasive species. We used a large-scale before-after control-impact removal experiment to investigate the effects of an invasive competitor, the barred owl (Strix varia), on the population dynamics of an iconic old-forest native species, the northern spotted owl (Strix occidentalis caurina). Removal of barred owls had a strong, positive effect on survival of sympatric spotted owls and a weaker but positive effect on spotted owl dispersal and recruitment. After removals, the estimated mean annual rate of population change for spotted owls stabilized in areas with removals (0.2% decline per year), but continued to decline sharply in areas without removals (12.1% decline per year). The results demonstrated that the most substantial changes in population dynamics of northern spotted owls over the past two decades were associated with the invasion, population expansion, and subsequent removal of barred owls. Our study provides experimental evidence of the demographic consequences of competitive release, where a threatened avian predator was freed from restrictions imposed on its population dynamics with the removal of a competitively dominant invasive species

Range-wide sources of variation in reproductive rates of northern spotted owls

We conducted a range-wide investigation of the dynamics of site-level reproductive rate of northern spotted owls using survey data from 11 study areas across the subspecies geographic range collected during 1993–2018. Our analytical approach accounted for imperfect detection of owl pairs and misclassification of successful reproduction (i.e., at least one young fledged) and contributed further insights into northern spotted owl population ecology and dynamics. Both nondetection and state misclassification were important, especially because factors affecting these sources of error also affected focal ecological parameters. Annual probabilities of site occupancy were greatest at sites with successful reproduction in the previous year and lowest for sites not occupied by a pair in the previous year. Site-specific occupancy transition probabilities declined over time and were negatively affected by barred owl presence. Overall, the site-specific probability of successful reproduction showed substantial year-to-year fluctuations and was similar for occupied sites that did or did not experience successful reproduction the previous year. Site-specific probabilities for successful reproduction were very small for sites that were unoccupied the previous year. Barred owl presence negatively affected the probability of successful reproduction by northern spotted owls in Washington and California, as predicted, but the effect in Oregon was mixed. The proportions of sites occupied by northern spotted owl pairs showed steep, near-monotonic declines over the study period, with all study areas showing the lowest observed levels of occupancy to date. If trends continue it is likely that northern spotted owls will become extirpated throughout large portions of their range in the coming decades

Suboxic DOM is bioavailable to surface prokaryotes in a simulated overturn of an oxygen minimum zone, Devil’s Hole, Bermuda

Oxygen minimum zones (OMZs) are expanding due to increased sea surface temperatures, subsequent increased oxygen demand through respiration, reduced oxygen solubility, and thermal stratification driven in part by anthropogenic climate change. Devil’s Hole, Bermuda is a model ecosystem to study OMZ microbial biogeochemistry because the formation and subsequent overturn of the suboxic zone occur annually. During thermally driven stratification, suboxic conditions develop, with organic matter and nutrients accumulating at depth. In this study, the bioavailability of the accumulated dissolved organic carbon (DOC) and the microbial community response to reoxygenation of suboxic waters was assessed using a simulated overturn experiment. The surface inoculated prokaryotic community responded to the deep (formerly suboxic) 0.2 μm filtrate with cell densities increasing 2.5-fold over 6 days while removing 5 μmol L−1 of DOC. After 12 days, the surface community began to shift, and DOC quality became less diagenetically altered along with an increase in SAR202, a Chloroflexi that can degrade recalcitrant dissolved organic matter (DOM). Labile DOC production after 12 days coincided with an increase of Nitrosopumilales, a chemoautotrophic ammonia oxidizing archaea (AOA) that converts ammonia to nitrite based on the ammonia monooxygenase (amoA) gene copy number and nutrient data. In comparison, the inoculation of the deep anaerobic prokaryotic community into surface 0.2 μm filtrate demonstrated a die-off of 25.5% of the initial inoculum community followed by a 1.5-fold increase in cell densities over 6 days. Within 2 days, the prokaryotic community shifted from a Chlorobiales dominated assemblage to a surface-like heterotrophic community devoid of Chlorobiales. The DOM quality changed to less diagenetically altered material and coincided with an increase in the ribulose-1,5-bisphosphate carboxylase/oxygenase form I (cbbL) gene number followed by an influx of labile DOM. Upon reoxygenation, the deep DOM that accumulated under suboxic conditions is bioavailable to surface prokaryotes that utilize the accumulated DOC initially before switching to a community that can both produce labile DOM via chemoautotrophy and degrade the more recalcitrant DOM