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UNDERSTANDING CHANGING GUIDANCE ON MASK USE: Kirsten Koehler and Ana Rule, DROPPS-III expert scientists from the Department of Environmental Health and Engineering, answer questions about the revised CDC guidelines on masks and gloves

May 2, 2020

Johns Hopkins University Hub staff report 

In early April, the Centers for Disease Control and Prevention revised its guidance to recommend that in addition to social distancing measures, all Americans should wear masks when leaving the house for essential trips such as going to the grocery store or the pharmacy. Thursday, Brigham and Women's Hospital in Boston reported that new COVID-19 infections among hospital staff dropped by half after instituting a universal masking

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Study Measures Size of Droplets Aerosolized from Bubbles Bursting on an Oil Slick

March 3, 2020
By Nilde Maggie Dannreuther

Scientists conducted laboratory experiments to learn more about particle emissions when bubbles on an oil slick burst. They observed that bubbles bursting on slicks containing crude oil and dispersant mixtures aerosolize micro-sized droplets (diameter is one thousandth of a millimeter) and nano-sized droplets (diameter is one billionth of a meter). In ambient air, there is a tenfold increase in the concentration of submicron-sized droplets (<one millionth of a meter) when large bubbles (>500 μm) burst on slicks containing dispersants. These results

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Petroleum Pollution Analysis with Ramped Pyrolysis GC–MS LCGC Europe spoke to Zhanfei Liu from the Marine Science Institute at the University of Texas at Austin, Texas USA, about the advantages of ramped pyrolysis GC–MS to analyze petroleum pollution

October 14, 2019
Interview by Alasdair Matheson, Editor-in-Chief, LCGC Europe

Q. You recently developed a method using ramped pyrolysis-gas chromatography–mass (Py-GC– MS) spectrometry to analyze petroleum pollution related to the Deepwater Horizon oil spill (1). How did this project arise?

A: Understanding the chemical composition of oil residues is essential for the oil-spill community, response team, and decision makers because the chemistry is related to evaluating toxicity of oil in environments and developing the appropriate response and remediation strategies. The traditional

Read more about Petroleum Pollution Analysis with Ramped Pyrolysis GC–MS LCGC Europe spoke to Zhanfei Liu from the Marine Science Institute at the University of Texas at Austin, Texas USA, about the advantages of ramped pyrolysis GC–MS to analyze petroleum pollution

Study IDs Oil-Degrading and Mucus-Producing Microbes Linked to Marine Oil Snow Formation

September 20, 2019

Scientists isolated bacteria from Gulf of Mexico surface waters and used them in microcosm experiments to identify those that simultaneously degrade oil and produce mucus-like materials (exopolymeric substances or EPS). Using 16S rRNA gene analysis, they identified Alteromonas and Thalassospira as the main bacteria species that produce EPS when consuming oil and/or dispersed oil. When the microbes consumed oil in the presence of Corexit, the EPS they produced had a higher protein-to-carbohydrate ratio (a 5- to 20-fold increase in protein) than oil-

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Grad Student Deng Investigates How Marine Microbes Move When Oil is Present

September 19, 2019

Oil-water interfaces, such as those formed by marine oil spills or natural ocean oil seeps, are teeming with bacterial activity. Some bacterial species in those interfaces form biofilms that help break up oil, which enhances biodegradation. The interfaces themselves can also significantly influence how bacteria behave, often trapping them or altering their natural movements.

Jiayi Deng tracks different

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Study Explains How Oil Spills Can Initiate Harmful Algal Blooms

August 20, 2019

By Nilde Maggie Dannreuther. 

Scientists conducted field and laboratory experiments using oil and Corexit dispersant to uncover the reasons harmful algal blooms, also known as Red Tides, can occur after an oil spill. They found that the presence of chemically-dispersed oil reduced the number of large protozoans (tintinnids and oligotrich ciliates that graze on dinoflagellates) which in turn was associated with an increase in bloom-forming dinoflagellates. The disruption in the predator-prey controls that normally function in plankton food webs could allow

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Study Shows How Copepods Can Change the Size Spectrum of Oil Droplets

April 16, 2019

 

By Nilde Maggie Dannreuther and Stephanie Ellis

Scientists conducted laboratory experiments to investigate if copepod behavior can reshape the size frequency distribution of oil droplets. They observed that copepods directly changed it through the combined movement of their feeding and swimming appendages and by ingesting oil droplets and discharging undigested, smaller-sized oil drops. The animals’ actions created feeding

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Study Creates Microcosm That Mimics Bacteria Encountering Rising Oil Droplets

March 19, 2019

By Nilde Maggie Dannreuther.

Scientists developed a platform at environmentally-relevant scales to advance the study of oil-water interface interactions, biofilm formation, and particle dispersion. Their techniques allow one to control the size, shape, and volume of oil micro-drops and then affix them onto a stable substrate where microbes can live and grow. The technology provides an unprecedented capability in investigating complex interactions of bacteria, cells, and interfaces and to study key microbial processes involved in remediation of environmental pollutants,

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