144 research outputs found
Diversity and toxicity of Pseudo-nitzschia species in Monterey Bay : perspectives from targeted and adaptive sampling
Author Posting. © The Author(s), 2018. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Harmful Algae 78 (2018): 129-141, doi:10.1016/j.hal.2018.08.006.Monterey Bay, California experiences near-annual blooms of Pseudo-nitzschia that can
affect marine animal health and the economy, including impacts to tourism and
commercial/recreational fisheries. One species in particular, P. australis, has been
implicated in the most toxic of events, however other species within the genus can
contribute to widespread variability in community structure and associated toxicity across
years. Current monitoring methods are limited in their spatial coverage as well as their
ability to capture the full suite of species present, thereby hindering understanding of
HAB events and limiting predictive accuracy. An integrated deployment of multiple in
situ platforms, some with autonomous adaptive sampling capabilities, occurred during
two divergent bloom years in the bay, and uncovered detailed aspects of population and
toxicity dynamics. A bloom in 2013 was characterized by spatial differences in Pseudo39
nitzschia populations, with the low-toxin producer P. fraudulenta dominating the inshore
community and toxic P. australis dominating the offshore community. An exceptionally
toxic bloom in 2015 developed as a diverse Pseudo-nitzschia community abruptly
transitioned into a bloom of highly toxic P. australis within the time frame of a week.
Increases in cell density and proliferation coincided with strong upwelling of nutrients.
High toxicity was driven by silicate limitation of the dense bloom. This temporal shift in
species composition mirrored the shift observed further north in the California Current
System off Oregon and Washington. The broad scope of sampling and unique platform
capabilities employed during these studies revealed important patterns in bloom
formation and persistence for Pseudo-nitzschia. Results underscore the benefit of
expanded biological observing capabilities and targeted sampling methods to capture
more comprehensive spatial and temporal scales for studying and predicting future
events.This work was
supported by the National Oceanic and Atmospheric Administration
(NA11NOS4780055, NA11NOS4780056, NA11NOS4780030) and a fellowship to H.
Bowers from the Packard Foundation
Autonomous tracking and sampling of the deep chlorophyll maximum layer in an open-ocean eddy by a long-range autonomous underwater vehicle
© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Zhang, Y., Kieft, B., Hobson, B. W., Ryan, J. P., Barone, B., Preston, C. M., Roman, B., Raanan, B., Marin,Roman,,III, O'Reilly, T. C., Rueda, C. A., Pargett, D., Yamahara, K. M., Poulos, S., Romano, A., Foreman, G., Ramm, H., Wilson, S. T., DeLong, E. F., Karl, D. M., Birch, J. M., Bellingham, J. G., & Scholin, C. A. Autonomous tracking and sampling of the deep chlorophyll maximum layer in an open-ocean eddy by a long-range autonomous underwater vehicle. IEEE Journal of Oceanic Engineering, 45(4), (2020): 1308-1321, doi:10.1109/JOE.2019.2920217.Phytoplankton communities residing in the open ocean, the largest habitat on Earth, play a key role in global primary production. Through their influence on nutrient supply to the euphotic zone, open-ocean eddies impact the magnitude of primary production and its spatial and temporal distributions. It is important to gain a deeper understanding of the microbial ecology of marine ecosystems under the influence of eddy physics with the aid of advanced technologies. In March and April 2018, we deployed autonomous underwater and surface vehicles in a cyclonic eddy in the North Pacific Subtropical Gyre to investigate the variability of the microbial community in the deep chlorophyll maximum (DCM) layer. One long-range autonomous underwater vehicle (LRAUV) carrying a third-generation Environmental Sample Processor (3G-ESP) autonomously tracked and sampled the DCM layer for four days without surfacing. The sampling LRAUV's vertical position in the DCM layer was maintained by locking onto the isotherm corresponding to the chlorophyll peak. The vehicle ran on tight circles while drifting with the eddy current. This mode of operation enabled a quasi-Lagrangian time series focused on sampling the temporal variation of the DCM population. A companion LRAUV surveyed a cylindrical volume around the sampling LRAUV to monitor spatial and temporal variation in contextual water column properties. The simultaneous sampling and mapping enabled observation of DCM microbial community in its natural frame of reference.10.13039/501100008982 - National Science Foundation
10.13039/100000936 - Gordon and Betty Moore Foundation
10.13039/100000008 - David and Lucile Packard Foundation
10.13039/100016377 - Schmidt Ocean Institute
10.13039/100000893 - Simons Foundatio
Positive and Negative Parenting in Conduct Disorder with High versus Low Levels of Callous-Unemotional Traits
Less is known about the relationship between conduct disorder (CD), callous-unemotional (CU) traits and positive and negative parenting in adolescence compared to early childhood. We combined traditional univariate analyses with a novel machine learning classifier (Angle-based Generalised Matrix Learning Vector Quantisation) to classify youth (N = 756; 9-18 years) into typically-developing (TD) or CD groups with or without elevated CU traits (CD/HCU, CD/LCU respectively) using youth- and parent-report measures of parenting behaviour. At the group level, both CD/HCU and CD/LCU were associated with high negative and low positive parenting relative to TD. However, only positive parenting differed between the CD/HCU and CD/LCU groups. In classification analyses, performance was best when distinguishing CD/HCU from TD groups and poorest when distinguishing CD/HCU from CD/LCU groups. Positive and negative parenting were both relevant when distinguishing CD/HCU from TD, negative parenting was most relevant when distinguishing between CD/LCU from TD, and positive parenting was most relevant when distinguishing CD/HCU from CD/LCU groups. These findings suggest that while positive parenting distinguishes between CD/HCU and CD/LCU, negative parenting is associated with both CD subtypes. These results highlight the importance of considering multiple parenting behaviours in CD with varying levels of CU traits in late childhood or adolescence
Autonomous Application of Quantitative PCR in the Deep Sea: In Situ Surveys of Aerobic Methanotrophs Using the Deep-Sea Environmental Sample Processor
Recent advances in ocean observing systems and genomic technologies have led to the development of the deep-sea environmental sample processor (D-ESP). The DESP filters particulates from seawater at depths up to 4000 m and applies a variety of molecular assays to the particulates, including quantitative PCR (qPCR), to identify particular organisms and genes in situ. Preserved samples enable laboratory-based validation of in situ results and expanded studies of genomic diversity and gene expression. Tests of the D-ESP at a methane-rich mound in the Santa Monica Basin centered on detection of 16S rRNA and particulate methane monooxygenase (pmoA) genes for two putative aerobic methanotrophs. Comparison of in situ qPCR results with laboratory-based assays of preserved samples demonstrates the D-ESP generated high-quality qPCR data while operating autonomously on the seafloor. Levels of 16S rRNA and pmoA cDNA detected in preserved samples are consistent with an active community of aerobic methanotrophs near the methane-rich mound. These findings are substantiated at low methane sites off Point Conception and in Monterey Bay where target genes are at or below detection limits. Successful deployment of the D-ESP is a major step toward developing autonomous systems to facilitate a wide range of marine microbiological investigations
Coda: posthumous conversations. A reading group to discuss the work of Dr Elee Kirk
In May 2017, a group of museum researchers and practitioners met to discuss the writing of Elee Kirk (1977–2016), whose pioneering doctoral study of young children visiting a natural history museum connects with our own work and practice in a number of different ways. Kirk [2015. “Budding Photographers: Young Children’s Digital Photography in a Museum.” In Museums and Visitor Photography: Redefining the Visitor Experience, edited by T. Stylianou-Lambert. MuseumsEtc] advocates for research that views children’s everyday museum visiting ‘beyond their potential for learning’ (p. 238). This paper offers edited transcripts of the discussion sparked by reading Kirk [2015. “Budding Photographers: Young Children’s Digital Photography in a Museum.” In Museums and Visitor Photography: Redefining the Visitor Experience, edited by T. Stylianou-Lambert. MuseumsEtc], documenting the conversation under a number of themes that emerged during the discussion, and reflecting on how each are picked up in more detail by the papers in this Special Issue
The COVID-19 pandemic and its global effects on dental practice : An International survey
Objectives: A multicentre survey was designed to evaluate the impact of COVID-19 outbreak on dental practice worldwide, estimate the COVID-19 related symptoms/signs, work attitudes and behaviour and the routine use of protective measures and Personal Protective Equipment (PPE). Methods: A global survey using a standardized questionnaire with research groups from 36 countries was designed. The questionnaire was developed and pretested during April 2020 and contained three domains: 1) Personal data; 2) COVID-19 positive rate and symptoms/signs presumably related to the coronavirus; 3) Working conditions and PPE adopted after the outbreak. Countries' data were grouped by the Country Positive Rate (CPR) during the survey period and by Gross-National-Income per capita. An ordinal multinomial logistic regression model was carried out with COVID-19 self-reported rate referred by dental professionals as dependent variable to assess the association with questionnaire items. Results: A total of 52,491 questionnaires were returned with a male/female ratio of 0.63. Out of the total respondents, 7,859 dental professionals (15%) reported symptoms/signs compatible with COVID-19. More than half of the sample (n = 27,818; 53%) stated to use FFP2/N95 masks, while 21,558 (41.07%) used eye protection. In the bivariate analysis, CPR and N95/FFP2 were significantly associated (OR = 1.80 95% =5.20 95% 95% CI = 1.60/2.82 and OR CI = 1.44/18.80, respectively), while Gross-National-Income was not statistically associated with CPR (OR = 1.09 CI = 0.97/1.60). The same significant associations were observed in the multivariate analysis. Conclusions: Oral health service provision has not been significantly affected by COVID-19, although access to routine dental care was reduced due to country-specific temporary lockdown periods. While the dental profession has been identified at high-risk, the reported rates of COVID-19 for dental professionals were not significantly different to those reported for the general population in each country. These findings may help to better plan oral health care for future pandemic events
Positive and Negative Parenting in Conduct Disorder with High versus Low Levels of Callous-Unemotional Traits
Less is known about the relationship between conduct disorder (CD), callous-unemotional (CU) traits, and positive and negative parenting in youth compared to early childhood. We combined traditional univariate analyses with a novel machine learning classifier (Angle-based Generalized Matrix Learning Vector Quantization) to classify youth (N = 756; 9-18 years) into typically developing (TD) or CD groups with or without elevated CU traits (CD/HCU, CD/LCU, respectively) using youth- A nd parent-reports of parenting behavior. At the group level, both CD/HCU and CD/LCU were associated with high negative and low positive parenting relative to TD. However, only positive parenting differed between the CD/HCU and CD/LCU groups. In classification analyses, performance was best when distinguishing CD/HCU from TD groups and poorest when distinguishing CD/HCU from CD/LCU groups. Positive and negative parenting were both relevant when distinguishing CD/HCU from TD, negative parenting was most relevant when distinguishing between CD/LCU and TD, and positive parenting was most relevant when distinguishing CD/HCU from CD/LCU groups. These findings suggest that while positive parenting distinguishes between CD/HCU and CD/LCU, negative parenting is associated with both CD subtypes. These results highlight the importance of considering multiple parenting behaviors in CD with varying levels of CU traits in late childhood/adolescence
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