Mass Stranding of Marine Birds Caused by a Surfactant-Producing Red Tide

In November-December 2007 a widespread seabird mortality event occurred in Monterey Bay, California, USA, coincident with a massive red tide caused by the dinoflagellate Akashiwo sanguinea. Affected birds had a slimy yellow-green material on their feathers, which were saturated with water, and they were severely hypothermic. We determined that foam containing surfactant-like proteins, derived from organic matter of the red tide, coated their feathers and neutralized natural water repellency and insulation. No evidence of exposure to petroleum or other oils or biotoxins were found. This is the first documented case of its kind, but previous similar events may have gone undetected. The frequency and amplitude of red tides have increased in Monterey Bay since 2004, suggesting that impacts on wintering marine birds may continue or increase

Assessment of intra-fraction motion during automated linac-based SRS treatment delivery with an open face mask system

To evaluate intra-fraction target shift during automated mono-isocentric linac-based stereotactic radiosurgery with open-face mask system and optical real-time tracking. Ninety-five patients were treated using automated linac-based stereotactic radiosurgery in 1-5 fractions with single isocenter for a total of 195 fractions. During treatment, patient positioning was tracked real-time with optical surface guidance and immobilized with a rigid open-face mask. Patients were re-positioned if optical surface guidance error exceeded 1 mm magnitude or 1°. Translational and rotational intra-fractional changes were determined by post-treatment CBCT matched to the planning CT. Target specific error was calculated by translation and rotation matrices applied to isocenter and target spatial coordinates. For 132 fractions with isocenter within a single target, the median shift magnitude was 0.40 mm with a maximum shift of 1.17 mm. A total of 398 targets treated for plans having multiple or single targets that lied outside isocenter, resulted in a median shift magnitude of 0.46 mm, with median translational shifts of 0.20 mm and 0.20° rotational shifts. A 1 mm PTV margin was insufficient in 18% of targets at a distance greater than 6 cm away from isocenter, but sufficient for 96% of targets within 6 cm. The findings of this study support 1 mm PTV expansion due to intra-fraction motion to ensure target coverage for plans with isocenter placement less than 6 cm away from the targets

Meta-analysis shows both congruence and complementarity of DNA and eDNA metabarcoding to traditional methods for biological community assessment

DNA metabarcoding is increasingly used for the assessment of aquatic communities, and numerous studies have investigated the consistency of this technique with traditional morpho-taxonomic approaches. These individual studies have used DNA metabarcoding to assess diversity and community structure of aquatic organisms both in marine and freshwater systems globally over the last decade. However, a systematic analysis of the comparability and effectiveness of DNA-based community assessment across all of these studies has hitherto been lacking. Here, we performed the first meta-analysis of available studies comparing traditional methods and DNA metabarcoding to measure and assess biological diversity of key aquatic groups, including plankton, microphytobentos, macroinvertebrates, and fish. Across 215 data sets, we found that DNA metabarcoding provides richness estimates that are globally consistent to those obtained using traditional methods, both at local and regional scale. DNA metabarcoding also generates species inventories that are highly congruent with traditional methods for fish. Contrastingly, species inventories of plankton, microphytobenthos and macroinvertebrates obtained by DNA metabarcoding showed pronounced differences to traditional methods, missing some taxa but at the same time detecting otherwise overseen diversity. The method is generally sufficiently advanced to study the composition of fish communities and replace more invasive traditional methods. For smaller organisms, like macroinvertebrates, plankton and microphytobenthos, DNA metabarcoding may continue to give complementary rather than identical estimates compared to traditional approaches. Systematic and comparable data collection will increase the understanding of different aspects of this complementarity, and increase the effectiveness of the method and adequate interpretation of the results.ISSN:0962-1083ISSN:1365-294

Yin Yang 1 sustains biosynthetic demands during brain development in a stage-specific manner

The transcription factor Yin Yang 1 (YY1) plays an important role in human disease. It is often overexpressed in cancers and mutations can lead to a congenital haploinsufficiency syndrome characterized by craniofacial dysmorphisms and neurological dysfunctions, consistent with a role in brain development. Here, we show that Yy1 controls murine cerebral cortex development in a stage-dependent manner. By regulating a wide range of metabolic pathways and protein translation, Yy1 maintains proliferation and survival of neural progenitor cells (NPCs) at early stages of brain development. Despite its constitutive expression, however, the dependence on Yy1 declines over the course of corticogenesis. This is associated with decreasing importance of processes controlled by Yy1 during development, as reflected by diminished protein synthesis rates at later developmental stages. Thus, our study unravels a novel role for Yy1 as a stage-dependent regulator of brain development and shows that biosynthetic demands of NPCs dynamically change throughout development.status: publishe

Why do toxic cyanobacteria bloom? A gene to ecosystem approach

This project aims to understand the ecological and evolutionary mechanisms triggering harmful cyanobacterial blooms (cyanoHABs) in lake ecosystems, and develop predictive models. We focus on bloom forming cyanobacteria (Oscillatoriales, Nostocales and Chroococcales) in temperate lakes and the production of known toxins and other bioactive metabolites. We are an interdisciplinary team of researchers in ecology, microbiology, environmental chemistry, and dynamical systems theory and together we focus on central questions about the mechanisms triggering cyanoHABs. We study the plankton seasonal progressions in a model lake (Greifensee, Switzerland) that has shown yearly occurrences of cyanoHABs. We test the relative importance and timing of different hypotheses of cyanoHAB drivers (water chemistry and physics, abundances of natural enemies and facilitative species). In parallel, we conductlaboratory experiments to estimate toxin production dynamics and fitness of cyanoHAB taxa relative to competitors in synthetically assembled communities, crossing community composition with environmental factors (e.g., temperature, nutrients, light, grazing). The range of important mechanisms will be constrained by data-analysis and modelling, and tested empirically by mesocosm experiments using natural lake plankton communities. The information acquired will be assimilated into data-driven models to forecast cyanoHABs, and integrated with previous knowledge to develop mechanistic models to predict the probability of cyanoHABs and associated communities based on fitness components and evolutionary strategies, under different environmental conditions (abiotic and biotic)

Yin Yang 1 Orchestrates a Metabolic Program Required for Both Neural Crest Development and Melanoma Formation

Increasing evidence suggests that cancer cells highjack developmental programs for disease initiation and progression. Melanoma arises from melanocytes that originate during development from neural crest stem cells (NCSCs). Here, we identified the transcription factor Yin Yang 1 (Yy1) as an NCSCs regulator. Conditional deletion of Yy1 in NCSCs resulted in stage-dependent hypoplasia of all major neural crest derivatives due to decreased proliferation and increased cell death. Moreover, conditional ablation of one Yy1 allele in a melanoma mouse model prevented tumorigenesis, indicating a particular susceptibility of melanoma cells to reduced Yy1 levels. Combined RNA sequencing (RNA-seq), chromatin immunoprecipitation (ChIP)-seq, and untargeted metabolomics demonstrated that YY1 governs multiple metabolic pathways and protein synthesis in both NCSCs and melanoma. In addition to directly regulating a metabolic gene set, YY1 can act upstream of MITF/c-MYC as part of a gene regulatory network controlling metabolism. Thus, both NCSC development and melanoma formation depend on an intricate YY1-controlled metabolic program.status: publishe

Perfluoroalkylphosphinic Acids in Northern Pike (Esox lucius), Double-Crested Cormorants (Phalacrocorax auritus), and Bottlenose Dolphins (Tursiops truncatus) in Relation to Other Perfluoroalkyl Acids

Perfluoroalkyl phosphinic acids (PFPIAs) are perfluoroalkyl acids (PFAAs) that are used for their surfactant properties in a variety of applications, resulting in their presence in environmental waters; however, they have not been widely studied in biota. A survey of PFPIAs was conducted in fish, dolphins, and birds from various locations in North America. Northern pike (Esox lucius) were collected at two locations in 2011 near Montréal Island in the St. Lawrence River, Canada, double-crested cormorants (Phalacrocorax auritus) were collected from bird colonies in the Great Lakes in 2010–2012, and bottlenose dolphins (Tursiops truncatus) from Sarasota Bay, FL and Charleston Harbor, SC were sampled in 2004–2009. PFPIAs had a detection frequency of 100% in all animals. This is the first report of PFPIAs in fish, dolphin, and bird plasma. Total PFPIA levels (mean ± standard deviation, 1.87 ± 2.17 ng/g wet weight (ww), range of 0.112–15.3 ng/g ww) were 1–2 orders of magnitude lower than those of perfluoroalkyl carboxylates (PFCA) and perfluoroalkanesulfonates (PFSA) in the same samples. The predominant congeners were 6:8 PFPIA (cormorants and pike) and 6:6 PFPIA (dolphins). Total PFPIAs in cormorants from Hamilton Harbour (5.02 ± 2.80 ng/g ww) were statistically higher than in other areas and taxonomic groups. The ubiquity of PFPIAs warrants further research on sources and effects of these unique compounds