Probably numerously more cold methane ocean seeps off the American Atlantic coast than previously thought

© 2014 Peter Free

Citation — to study

A. Skarke, C. Ruppel, M. Kodis, D. Brothers, and E. Lobecker, Widespread methane leakage from the sea floor on the northern US Atlantic margin, Nature Geoscience, DOI:10.1038/ngeo2232 (advance online publication, 24 August 2014)

Citation — to press release

US Geological Survey, Natural Methane Seepage on U.S. Atlantic Ocean Margin Widespread, United States Department of the Interior (25 August 2014)

Findings

From the abstract:

Here we use multibeam water-column backscatter data that cover 94,000 km2 of sea floor to identify about 570 gas plumes at water depths between 50 and 1,700 m between Cape Hatteras and Georges Bank on the northern US Atlantic passive margin.

About 440 seeps originate at water depths that bracket the updip limit for methane hydrate stability.

Contemporary upper-slope seepage there may be triggered by ongoing warming of intermediate waters, but authigenic [originating in place] carbonates observed imply that emissions have continued for more than 1,000 years at some seeps.

Extrapolating the upper-slope seep density on this margin to the global passive margin system, we suggest that tens of thousands of seeps could be discoverable.

© 2014 A. Skarke, C. Ruppel, M. Kodis, D. Brothers, and E. Lobecker, Widespread methane leakage from the sea floor on the northern US Atlantic margin, Nature Geoscience, DOI:10.1038/ngeo2232 (advance online publication, 24 August 2014) (paragraph split)

Method — multibeam water column backscatter

From the National Oceanic and Atmospheric Administration:

Multibeam sonar, an echo sounding technology commonly used to map the seafloor, can also be used to map and detect gaseous seeps in the water column, according to scientists testing the technology on board NOAA Ship Okeanos Explorer last week in the Gulf of Mexico.

Unlike other types of sonar, multibeam technology is able to survey a wide area of the seafloor and water column.

“This capability will help increase our knowledge of the marine environment, including the distribution of natural sources of methane input into the ocean and the identification of communities of life that are often associated with methane gas seeps,” said Thomas Weber, Ph.D. . . .

Since multibeam sonar obtains information from a wide fan-shape of beams, it maps a wider area more quickly and efficiently.

The multibeam sonar on Okeanos Explorer is one of the few that is specially configured to collect water column data to characterize gaseous seeps in wide areas of the deep-ocean’s water column in high resolution.

© 2014 Fred Gorell, NOAA and partners demonstrate success of multibeam sonar to detect and map deep-sea gas seeps, National Oceanic and Atmospheric Administration (25 September 2011) (extracts)

Study findings in more detail

From the US Geological Survey:

Methane plumes identified in the water column between Cape Hatteras, North Carolina and Georges Bank, Massachusetts, are emanating from at least 570 seafloor cold seeps on the outer continental shelf and the continental slope.

Taken together, these areas, which lie between the coastline and the deep ocean, constitute the continental margin.

Prior to this study, only three seep areas had been identified beyond the edge of the continental shelf, which occurs at approximately 180 meters (590 feet) water depth between Florida and Maine on the U.S. Atlantic seafloor.

Cold seeps are areas where gases and fluids leak into the overlying water from the sediments.  They are designated as cold to distinguish them from hydrothermal vents, which are sites where new oceanic crust is being formed and hot fluids are being emitted at the seafloor.  Cold seeps can occur in a much broader range of environments than hydrothermal vents.

“Widespread seepage had not been expected on the Atlantic margin. It is not near a plate tectonic boundary like the U.S. Pacific coast, nor associated with a petroleum basin like the northern Gulf of Mexico,” said Adam Skarke, the study’s lead author . . . .

The gas being emitted by the seeps has not yet been sampled, but researchers believe that most of the leaking methane is produced by microbial processes in shallow sediments.

This interpretation is based primarily on the locations of the seeps and knowledge of the underlying geology.  Microbial methane is not the type found in deep-seated reservoirs and often tapped as a natural gas resource.

Most [approximately 440 — see abstract] of the newly discovered methane seeps lie at depths close to the shallowest conditions at which deepwater marine gas hydrate can exist on the continental slope.

Gas hydrate is a naturally occurring, ice-like combination of methane and water, and forms at temperature and pressure conditions commonly found in waters deeper than approximately 500 meters (1640 feet).

Most seeps described in the new study are too deep for the methane to directly reach the atmosphere, but the methane that remains in the water column can be oxidized to carbon dioxide. This in turn increases the acidity of ocean waters and reduces oxygen levels.

© 2014 US Geological Survey, Natural Methane Seepage on U.S. Atlantic Ocean Margin Widespread, United States Department of the Interior (25 August 2014) (extracts)

Caveats

The gas has not been sampled. The team is assuming microbial origin. Educated guesses address whether the gas is making it into the atmosphere. One might (I assume) even be able to quarrel with the accuracy of multibeam water column backscatter in this context.

The moral? — There may be substantially more methane off the American Atlantic coast than previously realized

But it will take further investigation to prove its extent, volume, origin, and which portion of that is directly affecting the atmosphere.

Then one will want to estimate how global warming is affecting the seepage rate and its greenhouse influence.

Deterioration of inhibitory neurons — in the intermediate nucleus of the human hypothalamus — may account for fragmented sleep problems in the elderly and those with Alzheimer’s dementia — according to a study of 45 patients

© 2014 Peter Free

Citation — to study

Andrew S. P. Lim, Brian A. Ellison, Joshua L. Wang, Lei Yu, Julie A. Schneider, Aron S. Buchman, David A. Bennett, and Clifford B. Saper, Sleep is related to neuron numbers in the ventrolateral preoptic/intermediate nucleus in older adults with and without Alzheimer’s disease, Brain, DOI: 10.1093/brain/awu222 (advance access, 20 August 2014)

Citation — to press release

University of Toronto, New Research Helps Explain Why Elderly Are Prone to Sleep Problems, NewsWise (19 August 2014)

Findings

In one excellent summarizing sentence from the University of Toronto:

[T]he new findings demonstrate for the first time that a group of inhibitory neurons, whose loss leads to sleep disruption in experimental animals, are substantially diminished among the elderly and individuals with Alzheimer’s disease, and that this, in turn, is accompanied by sleep disruption.

© 2014 University of Toronto, New Research Helps Explain Why Elderly Are Prone to Sleep Problems, NewsWise (19 August 2014)

If more journalists would learn to think and write this clearly, we would be more knowledgeable.

In more detail

From the very nicely presented abstract:

In rodents, lesions of the hypothalamic ventrolateral preoptic nucleus cause fragmented sleep.

We previously proposed that the intermediate nucleus in the human hypothalamus, which has a similar location and neurotransmitter profile, is the homologue of the ventrolateral preoptic nucleus, but physiological data in humans were lacking.

We hypothesized that if the intermediate nucleus is important for human sleep, then intermediate nucleus cell loss may contribute to fragmentation and loss of sleep in ageing and Alzheimer’s disease.

We studied 45 older adults (mean age at death 89.2 years; 71% female; 12 with Alzheimer’s disease) from the Rush Memory and Aging Project, a community-based study of ageing and dementia, who had at least 1 week of wrist actigraphy [see here] proximate to death.

Upon death a median of 15.5 months later, we used immunohistochemistry [definition here] and stereology [here] to quantify the number of galanin [neuropeptide signaling molecule]-immunoreactive intermediate nucleus neurons in each individual, and related this to ante-mortem [before death] sleep fragmentation.

Individuals with Alzheimer’s disease had fewer galaninergic [activated by galanin] intermediate nucleus neurons than those without . . . .

Individuals with more galanin-immunoreactive intermediate nucleus neurons had less fragmented sleep, after adjusting for age and sex, and this association was strongest in those for whom the lag between actigraphy and death was <1 year . . . .

This association did not differ between individuals with and without Alzheimer’s disease, and similar associations were not seen for two other cell populations near the intermediate nucleus.

These data are consistent with the intermediate nucleus being the human homologue of the ventrolateral preoptic nucleus.

Moreover, they demonstrate that a paucity of galanin-immunoreactive intermediate nucleus neurons is accompanied by sleep fragmentation in older adults with and without Alzheimer’s disease.

Andrew S. P. Lim, Brian A. Ellison, Joshua L. Wang, Lei Yu, Julie A. Schneider, Aron S. Buchman, David A. Bennett, and Clifford B. Saper, Sleep is related to neuron numbers in the ventrolateral preoptic/intermediate nucleus in older adults with and without Alzheimer’s disease, Brain, DOI: 10.1093/brain/awu222 (advance access, 20 August 2014) (paragraph split)

This abstract is moderately unusual in presenting the study team’s reasoning and their technique in concise, yet logically understandable fashion.

The moral? — Interesting findings, well communicated

Both summaries of this research do what I think science should — communicate effectively with those who are outside the sub-discipline.

NOAA Land Cover Atlas study shows US coastal loss of 1,536 square miles of wetlands and 6.1 percent forest cover — from 1996 to 2011

© 2014 Peter Free

Citation

Ben Sherman and Kitty Fahey, NOAA analysis reveals significant land cover changes in U.S. coastal regions, National Oceanic and Atmospheric Administration (18 August 2014)

Keeping an inventory keeps our blather about conservation honest

From a biologist’s perspective, changes in land use almost never go in desirable directions:

Among the significant changes were the loss of 1,536 square miles of wetlands, and a decline in total forest cover by 6.1 percent.

The Northeast region added more than 1,170 square miles of development, an area larger than Boston, New York City, Philadelphia, Baltimore, and the District of Columbia combined.

The West Coast region experienced a net loss of 3,200 square miles of forest (4,900 square miles of forests were cut while 1,700 square miles were regrown).

The Great Lakes was the only region to experience a net wetlands gain (69 square miles), chiefly because drought and lower lake levels changed water features into marsh or sandy beach.

The Southeast region lost 510 square miles of wetlands, with more than half this number replaced by development.

Many factors led to the Gulf Coast region’s loss of 996 square miles of wetlands, due to land subsidence and erosion, storms, man-made changes, sea level rise, and other factors.

On a positive note, local restoration activities, such as in Florida’s Everglades, and lake-level changes enabled some Gulf Coast and Southeast region communities to gain modest-sized wetland areas, although such gains did not make up for the larger regional wetland losses.

© 2014 Ben Sherman and Kitty Fahey, NOAA analysis reveals significant land cover changes in U.S. coastal regions, National Oceanic and Atmospheric Administration (18 August 2014) (extracts)

The moral? — So much for conservation’s effectiveness

Six percent is a large loss in forest cover for such a short period of time.  Even more noticeable, from wildlife’s perspective, is the disappearance of 1,536 square miles of wetlands.

Now consider that this study did not address what is happening in the non-coastal areas of the United States.

When people compare humanity to a cancer of the biosphere, they are metaphorically correct.

Higher levels of Interleukin 6 at age 9 — in British children living in or near Bristol England — appear to increase the risk for depression (at age 18) by about 55 percent — and increase the risk for psychotic problems (also at age 18) by between 80 to 240 percent

© 2014 Peter Free

Citation — to study

Golam M. Khandaker, Rebecca M. Pearson, Stanley Zammit, Glyn Lewis, and Peter B. Jones, Association of Serum Interleukin 6 and C-Reactive Protein in Childhood With Depression and Psychosis in Young Adult Life: A Population-Based Longitudinal Study, JAMA Psychiatry, DOI:10.1001/jamapsychiatry.2014.1332 (online first, 13 August 2014)

Citation — to press release

University of Cambridge, Mind and body: Scientists identify immune system link to mental illness, ScienceDaily (13 August 2014)

Method and findings

From the press release:

A team of scientists led by the University of Cambridge studied a sample of 4,500 individuals from the Avon Longitudinal Study of Parents and Children [see here]– also known as Children of the 90s — taking blood samples at age 9 and following up at age 18 to see if they had experienced episodes of depression or psychosis.

The team divided the individuals into three groups, depending on whether their everyday levels of IL-6 [interleukin 6] were low, medium or high.

They found that those children in the ‘high’ group were nearly two times more likely to have experienced depression or psychosis than those in the ‘low’ group.

© 2014 University of Cambridge, Mind and body: Scientists identify immune system link to mental illness, ScienceDaily (13 August 2014) (paragraph split)

More precisely stated:

After adjusting for sex, age, body mass index, ethnicity, social class, past psychological and behavioral problems, and maternal postpartum depression,

participants in the top third of IL-6 values compared with the bottom third at age 9 years were

more likely to be depressed . . . at age 18 years . . . adjusted odds ratio [OR], 1.55 . . . .

[and]

Risks of PEs [psychotic experiences] and of psychotic disorder at age 18 years were also increased with higher IL-6 levels at baseline . . . adjusted OR, 1.81 . . . and adjusted OR, 2.40 . . . respectively).

Higher IL-6 levels in childhood were associated with subsequent risks of depression and PEs in a dose-dependent manner.

© 2014 Golam M. Khandaker, Rebecca M. Pearson, Stanley Zammit, Glyn Lewis, and Peter B. Jones, Association of Serum Interleukin 6 and C-Reactive Protein in Childhood With Depression and Psychosis in Young Adult Life: A Population-Based Longitudinal Study, JAMA Psychiatry, DOI:10.1001/jamapsychiatry.2014.1332 (online first, 13 August 2014) (at Abstract) (paragraph split and reformatted)

The moral? — Another hint that the body’s inflammatory immune response is sometimes dramatically not our friend

The size of these odds ratios are attention getting.  Correlations of this purported magnitude are somewhat unusual in medicine.

An especially antibiotic resistant strain of Pseudomonas aeruginosa showed up in Ohio — and it appears to include Salmonella resistance genes — illustrating the worrisome mobility of drug resistance genes among microorganisms

© 2014 Peter Free

Citation — to study

Federico Perez, Andrea M. Hujer, Steven H. Marshall, Amy J. Ray, Philip N. Rather, Nuntra Suwantarat, Donald Dumford III, Patrick O’Shea, T. Nicholas J. Domitrovic, Robert A. Salata, Kalyan D. Chavda, Liang Chen, Barry N. Kreiswirth, Alejandro J. Vila, Susanne Haussler, Michael R. Jacobs, and Robert. A. Bonomo, Extensively Drug Resistant (XDR) Pseudomonas aeruginosa Containing blaVIM-2 and Elements of Salmonella Genomic Island 2: A New Genetic Resistance Determinant in Northeast Ohio, Antimicrobial Agents and Chemotherapy, DOI: 10.1128/AAC.02372-14 (ahead of print, 28 July 2014)

Citation — to press release

Jim Sliwa, Highly Drug Resistant, Virulent Strain of Pseudomonas aeruginosa arises in Ohio, American Society of Microbiology (11 August 2014)

Findings

After one patient died, this research team found that an exceptionally resistant (bacterial) strain of Pseudomonas aeruginosa had developed metallo beta-lactamase-based resistance to all beta lactam, aminoglycoside and fluoroquinolone antibiotics, including colistin — a polymixin antibiotic that is considered a nephrotoxic drug of last resort in this context.

They winnowed the strain’s anti-drug activity down to a resistance-conferring transposon containing an added resistance-conveying integron.

Explaining these terms

From another paper:

The genes encoding metallo-beta-lactamases are often procured by class 1 (sometimes class 3) integrons, which, in turn, are embedded in transposons, resulting in a highly transmissible genetic apparatus.

© 2005 T R Walsh, M A Toleman, L Poirel, and P Nordmann, Metallo-beta-lactamases: the quiet before the storm?, Clinical Microbiology Reviews 18 (2): 306-25 (April 2005)

And Piklu Roy Chowdhury, H.W. Stokes, and Maurizio Labbate helpfully add this:

Integrons include a site‑specific recombination system that can capture gene cassettes.

Gene cassettes are the smallest known mobilizable units of DNA and normally only comprise a single gene and a recombination site essential for the site‑specific recombination event to occur.

Most notably, gene cassettes comprise a family of elements that are highly diverse both with respect to the genes and the recombination sites within them.

Integrons first came to prominence as a consequence of their infiltrating pathogenic Gram negative bacteria. In this context integrons commonly possess multiple cassettes with the associated genes conferring, collectively, resistance to a wide range of clinically important antibiotics.

Integrons however are ancient structures that are widely distributed among the Proteobacteria.

© 2013, Adam P. Roberts and Peter Mullany, Bacterial Integrative Mobile Genetic Elements, Madame Curie Bioscience Database – Landes Bioscience (2013) (at Chapter 3: “Integrons: Antibiotic Resistance Evolution and Beyond” by Piklu Roy Chowdhury, H.W. Stokes, and Maurizio Labbate) (extracts)

The Ohio specifics

From the abstract:

Seven patients were affected, hospitalized at three community hospitals, a long term care facility, and a tertiary care center; one of the patients died as a result of infection.

Isolates belonged to sequence type ST233, and were extensively drug resistant (XDR), including resistance to all fluoroquinolones, aminoglycosides and β-lactams; two isolates were non-susceptible to colistin.

The blaMBL gene was identified as blaVIM-2 contained within a class 1 integron (In559), similar to the cassette array previously detected in isolates from Norway, Russia, Taiwan, and Chicago.

Genomic sequencing and assembly revealed that In559 was part of a novel 35 Kb region that also included a Tn501-like transposon and Salmonella Genomic Island 2 (SGI2) homologous sequences.

This analysis of XDR strains producing VIM-2 from Northeast Ohio revealed a novel recombination event between Salmonella and P. aeruginosa, heralding a new antibiotic resistance threat in this region’s health care system.

© 2014 Federico Perez, Andrea M. Hujer, Steven H. Marshall, Amy J. Ray, Philip N. Rather, Nuntra Suwantarat, Donald Dumford III, Patrick O’Shea, T. Nicholas J. Domitrovic, Robert A. Salata, Kalyan D. Chavda, Liang Chen, Barry N. Kreiswirth, Alejandro J. Vila, Susanne Haussler, Michael R. Jacobs, and Robert. A. Bonomo, Extensively Drug Resistant (XDR) Pseudomonas aeruginosa Containing blaVIM-2 and Elements of Salmonella Genomic Island 2: A New Genetic Resistance Determinant in Northeast Ohio, Antimicrobial Agents and Chemotherapy, DOI: 10.1128/AAC.02372-14 (ahead of print, 28 July 2014)

The moral? — The antibiotic era is waning rapidly

Succinctly stated by co-author Federico Perez:

“This is the first description of genetic exchange of a large mobile element—the Salmonella Genome Island—and resistance genes between P. aerugenosa and Salmonella.

“This movement of genetic material creates concern that metallo beta-lactamases will disseminate rapidly in these enteric pathogens that are also very invasive.

“We are also concerned about the possibility of enhanced virulence.”

© 2014 Jim Sliwa, Highly Drug Resistant, Virulent Strain of Pseudomonas aeruginosa arises in Ohio, American Society of Microbiology (11 August 2014) (extracts)