Feed aggregator

Characterization of A20 and ABINs in amphioxus [Immunology]

PNAS Early Edition Articles - Mon, 04/21/2014 - 13:25
In the past decade, ubiquitination has been well documented to have multifaceted roles in regulating NF-κB activation in mammals. However, its function, especially how deubiquitinating enzymes balance the NF-κB activation, remains largely elusive in invertebrates. Investigating bbtA20 and its binding proteins, bbt A20-binding inhibitor of NF-κB (bbtABIN1) and bbtABIN2, in...

Bimodular NLS acts as an RNA-sensing NLS [Biochemistry]

PNAS Early Edition Articles - Mon, 04/21/2014 - 13:25
The human RNA-editing enzyme adenosine deaminase acting on RNA (ADAR1) carries a unique nuclear localization signal (NLS) that overlaps one of its double-stranded RNA-binding domains (dsRBDs). This dsRBD-NLS is recognized by the nuclear import receptor transportin 1 (Trn1; also called karyopherin-β2) in an RNA-sensitive manner. Most Trn1 cargos bear a...

Evolution of USA300 in a community [Microbiology]

PNAS Early Edition Articles - Mon, 04/21/2014 - 13:25
During the last 2 decades, community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) strains have dramatically increased the global burden of S. aureus infections. The pandemic sequence type (ST)8/pulsed-field gel type USA300 is the dominant CA-MRSA clone in the United States, but its evolutionary history and basis for biological success are incompletely understood....

Bjørn Lomborg: ‘Climate policies can end up costing more than 11% of world’s GDP’ – ‘We ought never to have entertained the notion that the world’s greatest challenge could be to reduce temperature rises in our generation by a fraction of a degree’

Climate Depot - Mon, 04/21/2014 - 08:15
http://www.project-syndicate.org/commentary/bj-rn-lomborg-says-that-the-un-climate-panel-s-latest-report-tells-a-story-that-politicians-would-prefer-to-ignore Lomborg Excerpt: We live in a world where one in six deaths are caused by easily curable infectious diseases; one in eight deaths stem from air pollution, mostly from cooking indoors with dung and twigs; and billions of people live in abject poverty, with no electricity and little food. We ought never to have [...]

Scientists concede global warming ‘pause’, but now say global temp is wrong thing to measure

Climate Depot - Mon, 04/21/2014 - 07:16
http://www.theguardian.com/news/2014/apr/20/weatherwatch-global-warming-ocean-heat-trade-winds     Has global warming come to a halt? For the last decade or so the average global surface temperature has stabilising at around 0.5°C above the long-term average. Can we all relax and assume global warming isn’t going to be so bad after all?   Unfortunately not. Instead we appear to be measuring [...]

‘The hilarious history of ‘climate tipping points’ – ‘Marc Morano at Climate Depot debunks the fake hysteria’ – ‘Saturday Night Live ought to be parodying’

Climate Depot - Mon, 04/21/2014 - 06:27

‘Super-fashionable Western fad’ – ‘Kenya shouldn’t waste time drafting climate change laws’

Climate Depot - Mon, 04/21/2014 - 05:49

Sea Ice Update April 20 2014 – Global Sea Ice 1.05 million sq km Above Normal – Antarctic Sea Ice 42nd Daily Record

Climate Depot - Sun, 04/20/2014 - 18:21
Sea Ice Update April 20 2014 – Global Sea Ice 1.05 million sq km Above Normal – Antarctic Sea Ice 42nd Daily Record http://sunshinehours.wordpress.com/2014/04/20/sea-ice-update-april-20-2014-global-sea-ice-1-05-million-sq-km-above-normal-antarctic-sea-ice-42nd-daily-record/ Happy Easter! A quick update for sea ice extent: Global Sea Ice Extent is 1,054,000 sq km above the 1981-2010 mean. Antarctic Sea Ice Extent is 1,673,000 sq km above the [...]

In the 1970’s, The Polar Vortex Was Caused By Global Cooling.

Climate Depot - Sun, 04/20/2014 - 09:24
In the 1970’s, The Polar Vortex Was Caused By Global Cooling. http://notalotofpeopleknowthat.wordpress.com/2014/04/18/in-the-1970s-the-polar-vortex-was-caused-by-global-cooling/ By Paul Homewood     The claims that the Polar Vortex, that has brought the cold winter in the States and wet weather to Britain, is linked to global warming are based on the theory of a weaker jet stream. The idea is [...]

Indian Climate Experts Slam Latest IPCC Report

Climate Depot - Sun, 04/20/2014 - 07:22
Indian Climate Experts Slam Latest IPCC Report http://www.thegwpf.org/indian-climate-experts-slam-latest-ipcc-report/ Climate policy experts from India have greeted the release of the latest report from the UN Intergovernmental Panel on Climate Change (IPCC) with ire. The draft report, a summary of which was released in Berlin, Germany, this week (13 April), is written by the IPCC’s third working [...]

Climate science: Autopsy of two mega-heatwaves

Nature Geoscience Advanced Online - Sat, 04/19/2014 - 23:00

Nature Geoscience. doi:10.1038/ngeo2148

Author: Erich M. Fischer

Record-breaking heatwaves in 2003 and 2010 surprised both the public and experts. Observations provide new insights into how temperatures escalated to unprecedented values through the interaction of boundary-layer dynamics and land surface drying.

Geochemistry: A piece of the deep carbon puzzle

Nature Geoscience Advanced Online - Sat, 04/19/2014 - 23:00

Nature Geoscience. doi:10.1038/ngeo2152

Author: Craig E. Manning

Carbon loss from subducting slabs is thought to be insufficient to balance carbon dioxide emissions at arc volcanoes. Analyses of ancient subducted rocks in Greece suggest that fluid dissolution of slab carbonate can help solve this carbon-cycle conundrum.

Carbon dioxide released from subduction zones by fluid-mediated reactions

Nature Geoscience Advanced Online - Sat, 04/19/2014 - 23:00

Nature Geoscience. doi:10.1038/ngeo2143

Authors: Jay J. Ague & Stefan Nicolescu

The balance between the subduction of carbonate mineral-bearing rocks into Earth’s mantle and the return of CO2 to the atmosphere by volcanic and metamorphic degassing is critical to the carbon cycle. Carbon is thought to be released from subducted rocks mostly by simple devolatilization reactions. However, these reactions will also retain large amounts of carbon within the subducting slab and have difficulty in accounting for the mass of CO2 emitted from volcanic arcs. Carbon release may therefore occur via fluid-induced dissolution of calcium carbonate. Here we use carbonate δ18O and δ13C systematics, combined with analyses of rock and fluid inclusion mineralogy and geochemistry, to investigate the alteration of the exhumed Eocene Cycladic subduction complex on the Syros and Tinos islands, Greece. We find that in marble rocks adjacent to two fluid conduits that were active during subduction, the abundance of calcium carbonate drastically decreases approaching the conduits, whereas silicate minerals increase. Up to 60–90% of the CO2 was released from the rocks—far greater than expected via simple devolatilization reactions. The δ18O of the carbonate minerals is 5–10 lighter than is typical for metamorphosed carbonate rocks, implying that isotopically light oxygen was transported by fluid infiltration from the surroundings. We suggest that fluid-mediated carbonate mineral removal, accompanied by silicate mineral precipitation, provides a mechanism for the release of enormous amounts of CO2 from subduction zones.

Mega-heatwave temperatures due to combined soil desiccation and atmospheric heat accumulation

Nature Geoscience Advanced Online - Sat, 04/19/2014 - 23:00

Nature Geoscience. doi:10.1038/ngeo2141

Authors: Diego G. Miralles, Adriaan J. Teuling, Chiel C. van Heerwaarden & Jordi Vilà-Guerau de Arellano

The recent European mega-heatwaves of 2003 and 2010 broke temperature records across Europe. Although events of this magnitude were unprecedented from a historical perspective, they are expected to become common by the end of the century. However, our understanding of extreme heatwave events is limited and their representation in climate models remains imperfect. Here we investigate the physical processes underlying recent mega-heatwaves using satellite and balloon measurements of land and atmospheric conditions from the summers of 2003 in France and 2010 in Russia, in combination with a soil–water–atmosphere model. We find that, in both events, persistent atmospheric pressure patterns induced land–atmosphere feedbacks that led to extreme temperatures. During daytime, heat was supplied by large-scale horizontal advection, warming of an increasingly desiccated land surface and enhanced entrainment of warm air into the atmospheric boundary layer. Overnight, the heat generated during the day was preserved in an anomalous kilometres-deep atmospheric layer located several hundred metres above the surface, available to re-enter the atmospheric boundary layer during the next diurnal cycle. This resulted in a progressive accumulation of heat over several days, which enhanced soil desiccation and led to further escalation in air temperatures. Our findings suggest that the extreme temperatures in mega-heatwaves can be explained by the combined multi-day memory of the land surface and the atmospheric boundary layer.

Sand as a stable and sustainable resource for nourishing the Mississippi River delta

Nature Geoscience Advanced Online - Sat, 04/19/2014 - 23:00

Nature Geoscience. doi:10.1038/ngeo2142

Authors: Jeffrey A. Nittrouer & Enrica Viparelli

The Mississippi River delta is undergoing a catastrophic drowning, whereby 5,000 km2 of low-lying wetlands have converted to open water over at least the past eight decades, as a result of many anthropogenic and natural factors. Continued net land loss has been thought inevitable due to a decline in the load of total suspended sediment—both sand and mud—carried by the river. However, sand—which accounts for 50–70% of modern and ancient Mississippi delta deposits but comprises only 20% of the sampled portion of the total load—could be more important than mud for subaerial delta growth. Historically, half of the Mississippi River sediment load is supplied by the Missouri River. Here we analyse suspended sediment load data from two locations downstream from the lowest Missouri River dam to show that the measured sand load in the lower 1,100 km of the Mississippi River has not significantly diminished since dam construction. A one-dimensional numerical model of river morphodynamics predicts that the sand load feeding the delta will decrease only gradually over the next several centuries, with an estimated decline from current values of no more than about 17% within the coming six centuries. We conclude that the lower Mississippi River channel holds a significant reservoir of sand that is available to replenish diminished loads via bed scour and substantially mitigate land loss.

Cool Heels on Climate Change Actions, Skeptics Say

Climate Depot - Sat, 04/19/2014 - 17:31
Syndicate content