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1. Distribution Patterns of Ciliate Diversity in the South China Sea

   https://doi.org/10.3389/fmicb.2021.689688  

   Liu, Weiwei; McManus, George B.; Lin, Xiaofeng; Huang, Honghui; Zhang, Wenjing; Tan, Yehui (September 2021, Frontiers in Microbiology)

   Ciliates are abundant microplankton that are widely distributed in the ocean. In this paper, the distribution patterns of ciliate diversity in the South China Sea (SCS) were analyzed by compiling community data from previous publications. Based on morphological identification, a total of 592 ciliate species have been recorded in the SCS. The ciliate communities in intertidal, neritic and oceanic water areas were compared in terms of taxonomy, motility and feeding habit composition, respectively. Significant community variation was revealed among the three areas, but the difference between the intertidal area and the other two areas was more significant than that between neritic and oceanic areas. The distributions of ciliates within each of the three areas were also analyzed. In the intertidal water, the community was not significantly different among sites but did differ among habitat types. In neritic and oceanic areas, the spatial variation of communities among different sites was clearly observed. Comparison of communities by taxonomic and ecological traits (motility and feeding habit) indicated that these traits similarly revealed the geographical pattern of ciliates on a large scale in the SCS, but to distinguish the community variation on a local scale, taxonomic traits has higher resolution than ecological traits. In addition, we assessed the relative influences of environmental and spatial factors on assembly of ciliate communities in the SCS and found that environmental selection is the major process structuring the taxonomic composition in intertidal water, while spatial processes played significant roles in influencing the taxonomic composition in neritic and oceanic water. Among ecological traits, environmental selection had the most important impact on distributions. 

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2. Biogeography of ocean acidification: Differential field performance of transplanted mussels to upwelling-driven variation in carbonate chemistry.

   https://doi.org/10.1371/journal.pone.0234075  

   Rose, Jeremy M.; Blanchette, Carol A.; Chan, Francis; Gouhier, Tarik C.; Raimondi, Peter T.; Sanford, Eric; Menge, Bruce A. (July 2020, PloS one)

   Griffen, Blaine D. (Ed.)

   Ocean acidification (OA) represents a serious challenge to marine ecosystems. Laboratory studies addressing OA indicate broadly negative effects for marine organisms, particularly those relying on calcification processes. Growing evidence also suggests OA combined with other environmental stressors may be even more deleterious. Scaling these laboratory studies to ecological performance in the field, where environmental heterogeneity may mediate responses, is a critical next step toward understanding OA impacts on natural communities. We leveraged an upwelling-driven pH mosaic along the California Current System to deconstruct the relative influences of pH, ocean temperature, and food availability on seasonal growth, condition and shell thickness of the ecologically dominant intertidal mussel Mytilus californianus. In 2011 and 2012, ecological performance of adult mussels from local and commonly sourced populations was measured at 8 rocky intertidal sites between central Oregon and southern California. Sites coincided with a large-scale network of intertidal pH sensors, allowing comparisons among pH and other environmental stressors. Adult California mussel growth and size varied latitudinally among sites and inter-annually, and mean shell thickness index and shell weight growth were reduced with low pH. Surprisingly, shell length growth and the ratio of tissue to shell weight were enhanced, not diminished as expected, by low pH. In contrast, and as expected, shell weight growth and shell thickness were both diminished by low pH, consistent with the idea that OA exposure can compromise shell-dependent defenses against predators or wave forces. We also found that adult mussel shell weight growth and relative tissue mass were negatively associated with increased pH variability. Including local pH conditions with previously documented influences of ocean temperature, food availability, aerial exposure, and origin site enhanced the explanatory power of models describing observed performance differences. Responses of local mussel populations differed from those of a common source population suggesting mussel performance partially depended on genetic or persistent phenotypic differences. In light of prior research showing deleterious effects of low pH on larval mussels, our results suggest a life history transition leading to greater resilience in at least some performance metrics to ocean acidification by adult California mussels. Our data also demonstrate “hot” (more extreme) and “cold” (less extreme) spots in both mussel responses and environmental conditions, a pattern that may enable mitigation approaches in response to future changes in climate. 

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3. Geotechnical Characterization of Underground Mine Excavations from UAV-Captured Photogrammetric & Thermal Imagery

   Turner, R.M.; Bhagwat, N.P.; Galayda, L.J.; Knoll, C.S.; Russell, E.A.; MacLaughlin, M.M. (June 2018, Proceedings of the 52nd US Rock Mechanics / Geomechanics Symposium)

   Geotechnical characterization of rock masses in underground mines often involves physical measurements in supported excavations. However, unsupported stopes and drifts prevent safe access for mapping by geotechnical personnel. The advent of inexpensive, open platform unmanned aerial vehicles (UAVs) allows geotechnical personnel to characterize hazardous rock masses by utilizing traditional photogrammetric and FLIR (forward looking infrared) imagery techniques. The photogrammetric imagery can be used to capture geological structural data from the rock mass for kinematic and numerical analyses, as well as for generating geological models. In particular, the FLIR imagery has the potential to assist in identifying areas of loose rock, which typically goes unnoticed until it becomes a hazard. This paper summarizes the results of a study involving UAV flights underground at the Barrick Golden Sunlight Mine, the generation of 3D models from UAV-captured imagery, and the identification of geological data from photogrammetry models. Results confirm that the combination of off-the-shelf technologies used in this study can be successfully employed as a geotechnical tool in the underground mining environment. 

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4. Persistence of aerially-sprayed naled in coastal sediments

   https://doi.org/https://doi.org/10.1016/j.scitotenv.2021.148701  

   Bamiduro, Gbemisola J.; Kumar, Naresh; Solo-Gabriele, H.M.; Zahran, Elsayed M. (January 2021, Science of the total environment)

   null (Ed.)

   Aerial sprays of the organophosphate pesticide, naled, were intensified over beach areas during the summer of 2016 to control the locally-acquired Zika outbreak in the continental U.S. Concerns were raised in beach frequented areas about contaminated sediments. The aim of this study was to evaluate the persistence and levels of naled and its byproduct, dichlorvos, in sediments obtained from the affected areas. Laboratory experiments were designed to simulate the effect of various natural conditions on the decomposition of naled in three sediment types (beach sand, marl, and calcinated beach sand). The three sediment samples were also exposed to field aerial sprays. After 30 min of exposure, more dichlorvos was detected in the sediments than naled, with 33 to 43% of the molar concentration initially applied as either naled or dichlorvos. Under dark conditions, trace levels of naled were observed after 24 h on sediments. Higher temperature accelerated the natural decomposition of both naled and dichlorvos in sediments. The half-life of naled ranged from 3 to 5 h at 22.5 °C and ranged from 1 to 3 h at 30 °C. Expedited decomposition of naled was observed under sunlight conditions with a half-life of naled of 20 min. In the field, only dichlorvos was detected in the sediment samples at concentrations between 0.0011 and 0.0028 μmol/g 1 h after aerial sprays. This data can be used towards a risk assessment that evaluates exposures to naled and dichlorvos through beach sands impacted by aerial spray activities. 

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5. Engineering Atomically Dispersed FeN ₄ Active Sites for CO ₂ Electroreduction

   https://doi.org/10.1002/anie.202012329  

   Mohd Adli, Nadia; Shan, Weitao; Hwang, Sooyeon; Samarakoon, Widitha; Karakalos, Stavros; Li, Yi; Cullen, David A.; Su, Dong; Feng, Zhenxing; Wang, Guofeng; et al (November 2020, Angewandte Chemie International Edition)

   Abstract Atomically dispersed FeN₄active sites have exhibited exceptional catalytic activity and selectivity for the electrochemical CO₂reduction reaction (CO2RR) to CO. However, the understanding behind the intrinsic and morphological factors contributing to the catalytic properties of FeN₄sites is still lacking. By using a Fe‐N‐C model catalyst derived from the ZIF‐8, we deconvoluted three key morphological and structural elements of FeN₄sites, including particle sizes of catalysts, Fe content, and Fe−N bond structures. Their respective impacts on the CO2RR were comprehensively elucidated. Engineering the particle size and Fe doping is critical to control extrinsic morphological factors of FeN₄sites for optimal porosity, electrochemically active surface areas, and the graphitization of the carbon support. In contrast, the intrinsic activity of FeN₄sites was only tunable by varying thermal activation temperatures during the formation of FeN₄sites, which impacted the length of the Fe−N bonds and the local strains. The structural evolution of Fe−N bonds was examined at the atomic level. First‐principles calculations further elucidated the origin of intrinsic activity improvement associated with the optimal local strain of the Fe−N bond. 

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