Development of a multiplex qPCR for the quantification of three protozoan parasites of the eastern oyster Crassostrea virginica

A multiplex quantitative PCR (qPCR) assay for the simultaneous detection of 3 eastern oyster Crassostrea virginica parasites, Perkinsus marinus, Haplosporidium nelsoni, and H. costale, was developed using 3 different fluorescently labeled hydrolysis probes. The primers and probe from a previously validated singleplex qPCR for P. marinus detection were combined with newly designed primers and probes specific for H. nelsoni and H. costale. The functionality of the multiplex assay was demonstrated on 2 different platforms by the linear relationship of the standard curves and similar cycle threshold (CT) values between parasites. Efficiency of the multiplex qPCR assay on the Roche and BioRad platforms ranged between 93 and 101%. The sensitivity of detection ranged between 10 and 100 copies of plasmid DNA for P. marinus and Haplosporidium spp., respectively. The concordance between the Roche and BioRad platforms in the identification of the parasites P. marinus, H. nelsoni, and H. costale was 91, 97, and 97%, respectively, with a 10-fold increase in the sensitivity of detection of Haplosporidium spp. on the BioRad thermocycler. The concordance between multiplex qPCR and histology for P. marinus, H. nelsoni, and H. costale was 54, 57, and 87%, respectively. Discordances between detection methods were largely related to localized or low levels of infections in oyster tissues, and qPCR was the more sensitive diagnostic. The multiplex qPCR developed here is a sensitive diagnostic tool for the quantification and surveillance of single and mixed infections in the eastern oyster

The Role of Spokesperson in Ambiguous and Complex Crises: The CDC and Anthrax

This study evaluates the role of spokespersons in complex organizations facing ambiguous crises. Specifically, the Centers for Disease Control and Prevention’s (CDC) response to the anthrax crisis in 2001 is offered as a case study. A content analysis of the print media coverage of the anthrax crisis reveals that many claiming affiliation with the CDC spoke on behalf of the organization, resulting in what appeared to be a fragmented CDC message. The study concludes that the CDC’s failure to provide a central spokesperson contributed to the ambiguity of the situation

Probiotic strains for disease management in hatchery larviculture of the eastern oyster Crassostrea virginica

Bacterial pathogens are a major cause of mortality in bivalve hatcheries, and outbreaks can result in shortages of seed supply to the grow-out industry. The use of probiotic bacteria is a potential preventative measure to limit the impact of bacterial diseases. Previous research showed that the marine bacteria Phaeobacter inhibens S4 (S4) and Bacillus pumilus RI06—95 (RI) protect larval eastern oysters (Crassostrea virginica) when challenged with the pathogens Vibrio tubiashii RE22 (now Vibrio coralliilyticus RE22) and Roseovarius crassostreae CV919-312T. In this study, these probiotic bacteria were tested under hatchery conditions. Daily addition of S4 and RI (104 colony forming units (CFU)/ml) to 100-l culture tanks resulted in a significant decrease in the levels of total Vibrios in water and tank surfaces (P < 0.05), but not in oysters. Larval growth and survival was unaffected by the probiotic treatments. Larvae treated with probiotics in the hatchery showed significantly less mortality than larvae from control tanks when exposed to 105 CFU/ml of V. coralliilyticus RE22 for 24 h in a laboratory challenge. These results suggest that S4 and RI are safe and potentially effective tools to limit disease outbreaks in oyster hatcheries

How Much Shallow Coral Habitat Is There on the Great Barrier Reef?

Australia’s Great Barrier Reef (GBR) is a globally unique and precious national resource; however, the geomorphic and benthic composition and the extent of coral habitat per reef are greatly understudied. However, this is critical to understand the spatial extent of disturbance impacts and recovery potential. This study characterizes and quantifies coral habitat based on depth, geomorphic and benthic composition maps of more than 2164 shallow offshore GBR reefs. The mapping approach combined a Sentinel-2 satellite surface reflectance image mosaic and derived depth, wave climate, reef slope and field data in a random-forest machine learning and object-based protocol. Area calculations, for the first time, incorporated the 3D characteristic of the reef surface above 20 m. Geomorphic zonation maps (0–20 m) provided a reef extent estimate of 28,261 km2 (a 31% increase to current estimates), while benthic composition maps (0–10 m) estimated that ~10,600 km2 of reef area (~57% of shallow offshore reef area) was covered by hard substrate suitable for coral growth, the first estimate of potential coral habitat based on substrate availability. Our high-resolution maps provide valuable information for future monitoring and ecological modeling studies and constitute key tools for supporting the management, conservation and restoration efforts of the GBR

Astrocyte development—More questions than answers

The past 15–20 years has seen a remarkable shift in our understanding of astrocyte contributions to central nervous system (CNS) function. Astrocytes have emerged from the shadows of neuroscience and are now recognized as key elements in a broad array of CNS functions. Astrocytes comprise a substantial fraction of cells in the human CNS. Nevertheless, fundamental questions surrounding their basic biology remain poorly understood. While recent studies have revealed a diversity of essential roles in CNS function, from synapse formation and function to blood brain barrier maintenance, fundamental mechanisms of astrocyte development, including their expansion, migration, and maturation, remain to be elucidated. The coincident development of astrocytes and synapses highlights the need to better understand astrocyte development and will facilitate novel strategies for addressing neurodevelopmental and neurological dysfunction. In this review, we provide an overview of the current understanding of astrocyte development, focusing primarily on mammalian astrocytes and highlight outstanding questions that remain to be addressed. We also include an overview of Drosophila glial development, emphasizing astrocyte-like glia given their close anatomical and functional association with synapses. Drosophila offer an array of sophisticated molecular genetic tools and they remain a powerful model for elucidating fundamental cellular and molecular mechanisms governing astrocyte development. Understanding the parallels and distinctions between astrocyte development in Drosophila and vertebrates will enable investigators to leverage the strengths of each model system to gain new insights into astrocyte function

Workflow for the generation of expert-derived training and validation data: a view to global scale habitat mapping

Our ability to completely and repeatedly map natural environments at a global scale have increased significantly over the past decade. These advances are from delivery of a range of on-line global satellite image archives and global-scale processing capabilities, along with improved spatial and temporal resolution satellite imagery. The ability to accurately train and validate these global scale-mapping programs from what we will call “reference data sets” is challenging due to a lack of coordinated financial and personnel resourcing, and standardized methods to collate reference datasets at global spatial extents. Here, we present an expert-driven approach for generating training and validation data on a global scale, with the view to mapping the world’s coral reefs. Global reefs were first stratified into approximate biogeographic regions, then per region reference data sets were compiled that include existing point data or maps at various levels of accuracy. These reference data sets were compiled from new field surveys, literature review of published surveys, and from individually sourced contributions from the coral reef monitoring and management agencies. Reference data were overlaid on high spatial resolution satellite image mosaics (3.7 m × 3.7 m pixels; Planet Dove) for each region. Additionally, thirty to forty satellite image tiles; 20 km × 20 km) were selected for which reference data and/or expert knowledge was available and which covered a representative range of habitats. The satellite image tiles were segmented into interpretable groups of pixels which were manually labeled with a mapping category via expert interpretation. The labeled segments were used to generate points to train the mapping models, and to validate or assess accuracy. The workflow for desktop reference data creation that we present expands and up-scales traditional approaches of expert-driven interpretation for both manual habitat mapping and map training/validation. We apply the reference data creation methods in the context of global coral reef mapping, though our approach is broadly applicable to any environment. Transparent processes for training and validation are critical for usability as big data provide more opportunities for managers and scientists to use global mapping products for science and conservation of vulnerable and rapidly changing ecosystems

A weak scientific basis for gaming disorder: let us err on the side of caution

We greatly appreciate the care and thought that is evident in the 10 commentaries that discuss our debate paper, the majority of which argued in favor of a formalized ICD-11 gaming disorder. We agree that there are some people whose play of video games is related to life problems. We believe that understanding this population and the nature and severity of the problems they experience should be a focus area for future research. However, moving from research construct to formal disorder requires a much stronger evidence base than we currently have. The burden of evidence and the clinical utility should be extremely high, because there is a genuine risk of abuse of diagnoses. We provide suggestions about the level of evidence that might be required: transparent and preregistered studies, a better demarcation of the subject area that includes a rationale for focusing on gaming particularly versus a more general behavioral addictions concept, the exploration of non-addiction approaches, and the unbiased exploration of clinical approaches that treat potentially underlying issues, such as depressive mood or social anxiety first. We acknowledge there could be benefits to formalizing gaming disorder, many of which were highlighted by colleagues in their commentaries, but we think they do not yet outweigh the wider societal and public health risks involved. Given the gravity of diagnostic classification and its wider societal impact, we urge our colleagues at the WHO to err on the side of caution for now and postpone the formalization

Mapping the world's coral reefs using a global multiscale earth observation framework

Coral reefs are among the most diverse and iconic ecosystems on Earth, but a range of anthropogenic pressures are threatening their persistence. Owing to their remoteness, broad spatial coverage and cross‐jurisdictional locations, there are no high‐resolution remotely sensed maps available at the global scale. Here we present a framework that is capable of mapping coral reef habitats from individual reefs (~200 km2) to entire barrier reef systems (200 000 km2) and across vast ocean extents (>6 000 000 km2). This is the first time this has been demonstrated using a consistent and transparent remote sensing mapping framework. The ten maps that we present achieved good accuracy (78% mean overall accuracy) from multiple input image datasets and training data sources, and our framework was shown to be adaptable to either benthic or geomorphic reef features and across diverse coral reef environments. These new generation high‐resolution map data will be useful for supporting ecosystem risk assessments, detecting change in ecosystem dynamics and targeting efforts to monitor local‐scale changes in coral cover and reef health

Multiplex qPCR Detection of Nonpathogenic and Pathogenic Vibrio parahaemolyticus and Vibrio vulnificus from Oysters Cultured in Massachusetts and Rhode Island: The Reliability of MPN as an Indicator

The leading cause of seafood-borne illness in the United States is Vibrio parahaemolyticus, whereas Vibrio vulnificus has the highest case fatality rate from wound infections of any foodborne pathogen. The Food and Drug Administration (FDA) uses a method of bacterial determination in oyster tissues termed most probable number (MPN) to enumerate Vibrio spp. abundance. This study used the development of two multiplex qPCR methods for the enumeration of total and pathogenic V. parahaemolyticus and V. vulnificus in oyster tissue using plasmid controls. Oysters, Crassostrea virginica, were collected from aquaculture farms in Wareham, MA, and Portsmouth, RI, from May to October 2014. Food and Drug AdministrationMPNand MPN-qPCR methods were compared and showed that FDA methods had higher values for both locations than MPN-qPCR methods. Throughout the summer at both locations, V. parahaemolyticus was most abundant with a majority being trh+ strains. Although serotypes were not directly tested for, tdh+ and trh+ strains were identified, suggesting a low possible occurrence of O4: K12 and no possible occurrence of O3:K6. In some samples, Vibrio alginolyticus was detected, indicating that trh+ percentages may be attributed to either V. parahaemolyticus or V. alginolyticus because of the similarity of the trh gene. The results from this study indicate the poor specificity and quantifiability of the FDA MPN method. This work also demonstrated that the use of plasmid controls for routine molecular methods to be used in a laboratory provided a reliable and consistent source of positive controls to compare against unknown samples for the abundance of V. parahaemolyticus and V. vulnificus