bluuebunny/crossref_metadata_2025 huggingface dataset:
Inland Flood Hazards: Human, Riparian, and Aquatic Communities
Authors: House P. Kyle
Published: October 2011

It is an immutable natural fact that floods happen. They have happened throughout Earth's history and, most likely, will continue in perpetuity. Floods and hydrological variability are fundamental natural processes that intimately affect many ecological phenomena. Floods and human society also share common ground—usually the floodplain—but their coexistence is often tenuous, uncertain, and disharmonious. Society's attempts to settle floodplain areas, control floods, and regulate stream flow often have adverse ecologic, aesthetic, and social consequences. These statements characterize the dominant thematic undercurrent that flows throughout Inland Flood Hazards: Human, Riparian, and Aquatic Communities. The book, which was edited by Ellen E. Wohl, is ambitiously comprehensive in scope and includes 19 chapters that focus on wide‐ranging topics related to floods. Twenty‐two authors contributed to the volume.
In Memoriam
Authors: Anonymous
Published: October 2011

Duwayne M. Anderson died last year, at age 75. He had been an AGU member (Planetology) since 1964.

Richard C. Culler died last year, at age 90. He was a retired life member (Hydrology) who joined AGU in 1949.
NASA workforce concerns
Authors: Showstack Randy
Published: October 2011

With nearly 25% of NASA's current workforce eligible to retire within five years, the agency faces “a huge retirement bulge,” according to U.S. Rep. Sherwood Boehlert (R‐NY). Boehlert, chair of the House of Representatives Science Committee, introduced legislation on 5 March to resolve these concerns by offering a package of stimuli to recruit and retain employees.

Boehlert said that although NASA is not the only agency facing workforce issues, NASA's needs “are especially critical.”
The digital revolution begets the global spatial data model (GSDM)
Authors: Burkholder Earl F.
Published: October 2011

Regardless of when the digital revolution began, profound changes have occurred during the past 50 years in the way spatial data are collected, stored, manipulated, and used. In years past, maps were made using plane table methods and other manual surveying techniques. But, mapping and automation of spatial data collection has progressed enormously since the 1950s and 1960s, when photogrammetric mapping techniques greatly simplified design activities for the U.S. interstate highway system. Similarly, the electronic calculator replaced the slide rule in the 1970s and surveyors have been using electronic total stations since the early 1980s. During the past 20 years, the global positioning system (GPS), geographic information systems (GISs), and the World Wide Web (WWW) have joined the technological onslaught, so that now spatial data can be characterized as digital and three‐dimensional (3‐D). Regretfully, development and implementation of the conceptual models used to handle spatial data have not kept pace. But a comprehensive 3‐D global spatial data model (GSDM) has been defined which accommodates new technology existing practices, and any location on Earth or within the birdcage of orbiting GPS satellites. Spatial data users in many disciplines all over the world stand to benefit from adopting and using a comprehensive standard 3‐D model.
Carbon fund could help developing countries
Authors: Showstack Randy
Published: October 2011

The Community Development Carbon Fund, which began operations on 25 July, could help developing countries gain financial support for small‐scale greenhouse gas reduction projects.

The fund would allow industrialized countries to receive greenhouse gas emission reduction credits for projects they support in developing countries. Projects would be developed under the Clean Development Mechanism of the Kyoto Protocol, and emissions reductions would be transferable under various carbon market regulatory regimes, including those established under the protocol and by the European Union.
SeaBED finds some healthy Caribbean coral reefs
Authors: Showstack Randy
Published: October 2011

A recent underwater survey has found that several Caribbean coral reefs are in better health than had been suspected, investigators announced on 24 July.

The June survey of two reef areas in the U.S. Virgin Islands used SeaBED, an autonomous underwater vehicle, and found well‐developed, deeper water coral reefs with nearly 100% living coral cover. The health of these reef areas, 30–80 meters below the surface in the Marine Conservation District Hind Bank and the South Drop, contrasts with the widespread coral mortality in shallower Caribbean reefs affected by disease, pollution, and run‐off.
Large Antarctic ozone loss foreseen
Authors: Showstack Randy
Published: October 2011

The ozone “hole” above Antarctica in late September and early October could be among the biggest on record, scientists with the Australian Antarctic Division and the Bureau of Meteorology predicted on 21 August. The scientists have found colder than usual atmospheric temperatures present, which contribute to ozone loss.

Australian Antarctic Division atmospheric scientist Andrew Klekociuk said the current meteorological trends are similar to those in 2000, a year when the ozone hole was of record size and covered an area about three times that of Australia. The first signs of cooling of the lower stratosphere were detected by lidar and balloon measurements at the Australian Antarctic Davis Station about 6 weeks earlier than during 2001 and 2002, he said. These cooling signs included the early detection of polar stratospheric clouds.
In Memoriam
Authors: Anonymous
Published: October 2011

Kazim Ergin, 86, 24 November 2002, Retired Life Member, Seismology, 1947.
Bush administration defends environmental policies
Authors: Showstack Randy
Published: October 2011

The chairman of the White House Council on Environmental Quality defended the Bush administration's initiatives on a wide range of environmental issues, including climate change, at a 22 January speech in Washington, D.C.

CEQ chair James Connaughton said that economic growth is the solution, rather than the problem, for dealing with a wide range of environmental issues. He said that as a society advances along an affluence curve, it is better able to engage in environmental protection measures.
In Memoriam
Authors: Anonymous
Published: October 2011

Francis R. “Joe” Boyd, 78, 13 January 2004, AGU Fellow, Volcanology Geochemistry, Petrology 1955.

John B. Ivey, 76, 11 July 2003,Tectonophysics, 1969.
Fine‐tuning particulate matter research
Authors: Showstack Randy
Published: October 2011

Determining the most hazardous chemical components and other characteristics of aerosol particulate matter should be a focus of research by the U.S. Environmental Protection Agency, according to a 24 March report by the National Research Council.

The NRC Committee on Research Priorities for Airborne Particulate Matter found that research specifically should focus on the impacts of particulate matter—such as dust, smoke, and soot—when it is mixed in a real‐life “soup” with other airborne contaminants.
Hundreds of U.S. countries fail ozone standards
Authors: Showstack Randy
Published: October 2011

About 159 million residents live in the 474 U.S. counties that either do not meet the 8‐hour standard for ground‐level ozone, or cause a downwind county to fail meeting the standard, the U.S. Environmental Protection Agency announced on 15 April.

Eighteen entire states met the standard. EPA also announced a new rule to classify areas by the severity of ozone conditions, and a set of Clean Air Rules of 2004 to help states and counties meet the standard.
AGU position statement on the need for balance between small and large science
Authors: Anonymous
Published: October 2011

A proper balance of government support between science carried out by individuals or small teams of investigators and large scientific data gathering programs is critical to maintaining the health of scientific research.The scientific enterprise has always shown the highest levels of success because of the synergism generated between these two activities. Research done by individuals or small teams of investigators, sometimes called "small science," has been crucial for many of the important discoveries made in all branches of science.These discoveries provide the fundamental basis for the application of scientific knowledge to national economic and societal goals. Small science helps define the goals and directions of large scientific data gathering projects. In turn, these data feed and are often best synthesized and interpreted by the long‐term efforts of the small science community In addition, because small science is typically done at universities, it provides students with an integral involvement in defining and solving scientific problems. Any erosion in government support for small science would therefore weaken not only the entire scientific enterprise, but also our future ability to utilizescientific information for the national good.
U.K.'s leading carbon cycle research effort
Authors: Jacobs Judy
Published: October 2011

The U.K.'s Natural Environment Research Centre (NERC) is launching QUEST, a 5‐year, $45.25‐million project to improve quantitative and qualitative understanding of large‐scale processes and interactions in the Earth system.

The research program will have three main components, focusing on (1) the contemporary carbon cycle and its interactions with climate and atmospheric chemistry; (2) the natural regulation of atmospheric composition on glacial‐interglacial and longer time scales; and (3) the implications of global environmental changes for the sustainable use of resources. Among its objectives are to improve understanding of the pattern and mechanisms for land and ocean uptake of anthropogenically‐sourced carbon dioxide.
Honors
Authors: Anonymous
Published: October 2011

Robert Kovach's second book looks at the interplay of earthquake and volcanic events, archeology and history in the Americas. Throughout history, major earthquakes have caused the deaths of millions of people and have damaged countless cities. Earthquakes undoubtedly damaged prehistoric cities in the Americas, and evidence of these events could be preserved in archeological records.

Kovach asks, Did indigenous native cultures—Indians of the Pacific Northwest, Aztecs, Mayas, and Incas—document their natural history? Some events have been explicitly documented, for example, in Mayan codices, but many may have been recorded as myth and legend. Kovach's discussions of how early cultures dealt with fearful events such as earthquakes and volcanic eruptions are colorful, informative, and entertaining, and include, for example, a depiction of how the Maya would talk to maize plants in their fields during earthquakes to reassure them.
Argo Network reaches half‐way mark
Authors: Showstack Randy
Published: October 2011

Researchers with the international Argo program announced on 30 November that 1,500 ocean‐traveling float instruments, one‐half of the target number, are now in operation. Argo floats are programmed to sink far below the ocean surface and drift for up to 4 years.

Every 10 days the instruments surface to relay temperature, salinity, and current information to satellites.
NASA satellite data will help conservation
Authors: Showstack Randy
Published: October 2011

NASA and the World Conservation Union (IUCN), the world's largest environmental knowledge network, signed a joint declaration on 18 November to use NASA satellite data to assist with worldwide conservation efforts.

sist with worldwide conservation efforts. The joint declaration is meant to improve IUCN access to NASA data, technology, images, and remote sensing products.
Changes at USGS
Authors: Showstack Randy
Published: October 2011

Charles “Chip” Groat, director of the U.S. Geological Survey since 1998, resigned from the agency on 17 June to become founding director of The University of Texas at Austin's new Center for International Energy and Environmental Policy.

P. Patrick Leahy, the Survey's associate director for geology, has been named as interim director of USGS. A permanent director must be nominated by U.S. President Bush and confirmed by the U.S. Senate.
In Memoriam
Authors: Anonymous
Published: October 2011

Bruce A. Bolt, 75, 21 July 2005, AGU Fellow, Seismology, 1963.

Larry H. Brace, 76, 28 August 2005, Planetology, 1960.
In Memoriam
Authors: Anonymous
Published: October 2011

Lawrence Chitwood, 65, 2 January 2008, Volcanology, Geochemistry, and Petrology, 1978

Steven J. Drussell II, 49, 5 March 2008, Life Member, Volcanology, Geochemistry, and Petrology, 1987
In Memoriam
Authors: Anonymous
Published: October 2011

Lloyd O. Bacon, 92, 15 April 2008, Geomagnetism and Paleomagnetism, 1946

Fedor Ostapoff, 83, 2 June 2008, Ocean Sciences, 1958
In Memoriam
Authors: Anonymous
Published: October 2011

Sidney Kaufman, 100, 23 October 2008, Seismology, 1961
In Memoriam
Authors: Anonymous
Published: October 2011

Kevin J. R. Rosman, 66, 23 March 2009, Global Environmental Change, 1988.
Research Spotlight: Modeling groundwater age in large aquifer systems
Authors: Tretkoff Ernie
Published: October 2011

Groundwater age, the amount of time groundwater has been in an aquifer, is important because the length of time water spends in an aquifer can influence many geologic processes. However, determining groundwater age—which can be as short as a few days or as long as thousands of years—can be complicated because groundwater basins are large and complex and groundwater age distribution is affected by mixing and transport of different parcels of water.
Research Spotlight: Explaining strange features of sprite lightning
Authors: Tretkoff Ernie
Published: October 2011

A sprite is an electrical discharge similar to lightning, but it occurs in the upper atmosphere (at altitudes of 50–90 kilometers), above large thunderstorms. These large flashes of light, which are triggered in almost all cases by a rare lightning form in which positive charge is held at the top of clouds rather than the ground, can span tens of kilometers of altitude.
Research Spotlight: Sunlight reflection confirms liquid lake on Titan
Authors: Tretkoff Ernie
Published: October 2011

A glint of sunlight reflecting from the surface of Saturn's moon Titan indicates the presence of a lake filled with liquid. Earlier observations showed features that look like terrestrial lakes and seas in Titan's northern polar region, but the presence of liquid had not been confirmed. Stephan et al. report the first detection of a directly visible glint, also called a specular reflection.

A specular reflection occurs when sunlight reflects off a smooth, mirror‐like liquid surface. Cassini captured an image of the glint on 8 July 2009, and the researchers determined that it came from Kraken Mare, a large basin near Titan's north pole. Until recently the northern polar regions of Titan had been in winter darkness since Cassini's arrival in 2004; the recent direct illumination by sunlight made it possible to observe these optical reflections for the first time. Titan is the only body other than Earth in the solar system known to have stable liquid on its surface.
Research Spotlight: Simple description of atmospheric organic aerosol
Authors: Tretkoff Ernie
Published: October 2011

Atmospheric organic aerosols consist of a variety of organic molecules that are either directly emitted into the atmosphere or formed through chemical reactions in the atmosphere. Organic aerosols can affect climate by altering the amount of sunlight that is reflected away from Earth. Because the aerosol composition changes as chemical reactions take place in the atmosphere and air masses move and mix, it is difficult and time consuming for atmospheric chemistry models to include the details of the evolution of organic aerosol composition. A new study shows that it may not be necessary for models to include all the details.
Research Spotlight: Airborne study reveals Arctic sea ice thickness
Authors: Tretkoff Ernie
Published: October 2011

Arctic sea ice extent has declined over the past several decades and in 2007 reached a record‐breaking low. Since then, ice has begun to recover. Sea ice thinning is expected to continue with climate change, although there is significant natural variability in ice extent and thickness. To understand the effects of climate change on sea ice and to make forecasts, scientists need reliable sea ice thickness data, but Arctic sea ice thickness information is scarce.
In Memoriam
Authors: Anonymous
Published: October 2011

Norihiko Fukuta, 78, 3 May 2010, Atmospheric Sciences, 1968

Gerhard Jirka, 65, 14 February 2010, Hydrology, 1974
Research Spotlight: Inappropriate data filtering skewed a recent study
Authors: Kumar Mohi , Tretkoff Ernie
Published: October 2011

About every 4 years, faltering easterly trade winds over the tropical Pacific Ocean cause warm waters to linger, generating an anomalously warm wet period in the eastern Pacific for about 6 months. During these times, the western Pacific becomes cooler and drier. A few years later, a reversal of these conditions occurs when trade winds amplify, pushing warm waters even farther west, leading to unusually cool waters across a broad expanse of the equatorial Pacific.
Research Spotlight: Can California's water supply infrastructure handle severe prolonged drought?
Authors: Kumar Mohi , Ofori Leslie , Tretkoff Ernie
Published: October 2011

Recent studies show that prolonged episodes of extreme drought have occurred in the past and may be more likely due to human‐induced greenhouse warming. This is of particular concern in California, which contributes more than 10% of the agricultural economy of the United States. In this context, Harou et al. seek to examine whether current infrastructure systems can adapt to possible future prolonged and severe drought.
Research Spotlight: Is there a relationship between aerosol and cloud properties?
Authors: Kumar Mohi , Ofori Leslie , Tretkoff Ernie
Published: October 2011

The interaction of aerosols and clouds is a significant uncertainty in studies of anthropogenic forcing of climate. To learn more about the effects of fine aerosols on cloud microphysics, Costantino and Bréon performed a multisensor analysis of the atmosphere off the southwest coast of Africa. They chose this particular area because it is often affected by smoke from biomass burning. The aerosol particles from this smoke are transported by trade winds into the atmosphere, where they come in contact with low‐level stratocumulus clouds.
Research Spotlight: Nonuniform data created spurious trend in sunshine hours
Authors: Kumar Mohi , Ofori Leslie , Tretkoff Ernie
Published: October 2011

With climate change an increasingly important scientific and political issue, it is essential to have an accurate picture of the causes of regional climate changes. In most cases, warming has been related to a combination of anthropogenic and natural factors. However, regional data are often nonuniform and can be difficult to analyze, sometimes leading to incorrect conclusions.
Research Spotlight: Kelvin‐Helmholtz waves observed in flyby of Mercury
Authors: Ofori Leslie , Tretkoff Ernie
Published: October 2011

Kelvin‐Helmholtz waves, the surface waves that form when two fluids with different speeds move past each other, can be created along the magnetopause when solar wind plasma interacts with a planet's magnetosphere. These waves have previously been observed in Earth's magnetosphere. Now they have been observed in Mercury's magnetosphere as well. On 29 September 2009, the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft flew by the planet Mercury for the third time.
Research Spotlight: A case study of satellite monitoring of ammonia
Authors: Ofori Leslie , Tretkoff Ernie
Published: October 2011

Emissions of ammonia (NH3), which come mainly from agriculture, have increased in recent decades and are likely to continue to rise as the world's population grows and demand for food increases. Ammonia pollutes the air, increases creation of particulate matter, and contributes to deposition of reactive nitrogen in sensitive ecosystems. Ground‐based ammonia measurements are sparse, and although some monitoring of atmospheric ammonia has been conducted with infrared sounders from space, so far these observations have been limited and errors are often high.
Research Spotlight: Large atmospheric study investigates tropical tropopause transition layer
Authors: Ofori Leslie , Tretkoff Ernie
Published: October 2011

The tropical tropopause transition layer (TTL), starting at about 12 kilometers in altitude, is a transition layer between the tropical troposphere (the layer nearest Earth) and the stratosphere above. The TTL can influence the chemistry of the stratosphere, including the global ozone budget. In addition, understanding how water and other greenhouse gases behave in the TTL is important to understanding the greenhouse effect and global climate change.
Research Spotlight: Globalization of water can increase vulnerability to droughts
Authors: Ofori Leslie , Tretkoff Ernie
Published: October 2011

Water is vital for human life. Not only is it used for drinking, but it is also used for producing electricity, washing, cooking, and growing food. Lately there has been a disproportionate population growth in arid regions, and the demand for water in those regions exceeds the limited supply. However, food imports from other regions have in effect transported water to arid regions, because food is composed primarily of water.
Research Spotlight: What are the effects of controlling fossil fuel soot?
Authors: Ofori Leslie , Tretkoff Ernie
Published: October 2011

Fossil fuel soot, emitted during combustion of diesel fuel, jet fuel, and coal, and biofuel soot, emitted mainly through burning of wood and organic waste for heating and cooking, can affect climate and air quality. How much does each of these contribute to global warming? What would be the effects of limiting fossil fuel and biofuel soot emissions? To find out, Jacobson used climate model simulations to investigate and compare the short‐term effects of controlling fossil fuel and biofuel soot, as well as methane and carbon dioxide.
Research Spotlight: El Niño and North Atlantic Oscillation bring heavy snowfall
Authors: Ofori Leslie , Tretkoff Ernie
Published: October 2011

The winter of 2009–2010 had anomalously large snowfall in central parts of the United States, particularly the mid‐Atlantic states, and in northwestern Europe. After studying 60 years of snowfall measurements, Seager et al. found that the anomalous winter was caused by two colliding weather events, El Niño and the negative North Atlantic Oscillation (NAO). El Niño is an anomalous warming of surface ocean waters in the eastern tropical Pacific. The NAO is a fluctuation of atmospheric pressure above the North Atlantic Ocean.
Research Spotlight: Changes in Sun's plasma conveyor belt affect solar cycle
Authors: Ofori Leslie , Tretkoff Ernie
Published: October 2011

The Sun goes through cycles lasting approximately 11 years that include phases with increased magnetic activity, more sunspots, and more solar flares, and phases with less activity. The level of activity on the Sun can affect navigation and communications systems on Earth. Puzzlingly, solar cycle 23, which ended recently, lasted longer than previous cycles, with a prolonged phase of low activity that scientists had difficulty explaining.
Research Spotlight: Ozone hole shift exposed South America to increased ultraviolet light
Authors: Ofori Leslie , Tretkoff Ernie
Published: October 2011

The ozone layer, which protects humans, plants, and animals from potentially damaging ultraviolet (UV) light from the Sun, develops a hole above Antarctica in September that typically lasts until early December. However, in November 2009, that hole shifted its position, leaving the southern tip of South America exposed to UV light at levels much greater than normal.
Research Spotlight: Landmass geometry constrains Arctic sea ice extent
Authors: Ofori Leslie , Tretkoff Ernie
Published: October 2011

Arctic sea ice has retreated significantly in recent years, reaching a record low in September 2007. It is known that the seasonal cycle in Arctic sea ice extent is not symmetric—seasonal ice retreat proceeds gradually during early summer and then accelerates toward end of summer; in winter, ice growth is rapid at first and then slows later in the season. Scientists have observed that ice cover has retreated far more rapidly in September than during other times of the year.
Research Spotlight: Interplanetary magnetic field direction affects the ionosphere
Authors: Ofori Leslie , Tretkoff Ernie
Published: October 2011

Electron density variations in the ionosphere are important for understanding space weather because they affect the Global Positioning System and radio communications. Bahcivan et al. used some of the first measurements from the U.S. National Science Foundation's Resolute incoherent scatter radar in Resolute Bay, Canada (near the geomagnetic pole), to investigate the highly structured polar cap ionosphere.
In Memoriam
Authors: Anonymous
Published: October 2011

Pearn Peter Niiler, 73, 15 October 2010, Fellow, Ocean Sciences, 1967
Research Spotlight: No lightning detected on Mars during 5‐year search
Authors: Tretkoff Ernie
Published: October 2011

It has been suggested that dust storms on Mars might generate electric fields large enough to produce lightning‐like electrical discharges, and a recent study reported evidence of such lightning. If lightning does occur on Mars, it could present a hazard for spacecraft or manned missions to the planet. However, Gurnett et al. report that a 5‐year search using a radar receiver on board the Mars Express spacecraft found no evidence of lightning at frequencies between 4.0 and 5.5 megahertz, although there were two major dust storms and many smaller storms during the time period. The search does not rule out the possibility of lighnting on Mars at substantially higher or lower frequencies.
Research Spotlight: Limiting global warming may not limit heat wave risk
Authors: Tretkoff Ernie
Published: October 2011

Recent policy discussions on climate change have focused on limiting global average temperature increases. For instance, the European Union has set a goal of limiting global warming to 2°C. However, this goal represents a global average; regional and local temperature changes may vary, and substantial increases in regional extreme heat events could occur, possibly with serious consequences for some communities.
In Memoriam
Authors: Anonymous
Published: October 2011

William Pelton, 64, 19 August 2010, Tectonophysics, 2005
Research Spotlight: Simulations show deep oil from leak is confined to Gulf of Mexico
Authors: Kumar Mohi , Tretkoff Ernie
Published: October 2011

The Deepwater Horizon oil leak caused severe environmental damage in the Gulf of Mexico, and aspects of its environmental impact are still unknown. In addition to surface oil slicks, large underwater plumes of oil were found.

To help evaluate the potential environmental impact, Adcroft et al. ran simulations of underwater plumes of dissolved and suspended oil originating from a point source in the Gulf of Mexico. They assessed dispersal and decay mechanisms, examining the possibility that toxic concentrations of dissolved oil might exit the Gulf of Mexico.
Research Spotlight: Modeling ionospheric variations
Authors: Kumar Mohi , Tretkoff Ernie
Published: October 2011

Plasma density irregularities in the ionosphere are important to understand and predict because they can cause radio scintillation that affects communications and navigation systems.

During an ionospheric phenomenon known as equatorial spread F (ESF), large‐scale electron density bubbles can be generated and rise to high altitudes.
Research Spotlight: Teasing out how aerosol levels influence precipitation
Authors: Kumar Mohi , Tretkoff Ernie
Published: October 2011

Aerosol particles such as dust, smog, smoke, and oceanic haze play an important role in the physics of cloud generation—with all other factors fixed, an increase in aerosol concentrations results in more numerous but smaller water droplets within clouds. Further, high concentrations of aerosols make it harder for cloud droplets to coalesce into larger droplets, thus suppressing the ability of clouds to form rain. However, the nature and magnitude of this effect are highly uncertain, making it difficult to model how increased pollution levels will affect rain patterns.
Research Spotlight: Tropical cyclone formation affected by ocean color
Authors: Tretkoff Ernie
Published: October 2011

The color of the ocean can alter the frequency of tropical cyclones, according to a new study. The absorption of sunlight is affected by the concentration of chlorophyll, with the Sun's heat penetrating deeper in clear, low‐chlorophyll waters. In the ocean gyres this heat can get carried away so that lower concentrations of chlorophyll are associated with colder surface waters. Ocean surface temperatures can affect atmospheric circulation patterns and thus the formation of cyclones and other weather patterns.
Research Spotlight: Understanding the eruption of the Soufrière Hills volcano
Authors: Tretkoff Ernie
Published: October 2011

When the Soufrière Hills volcano erupted in 1995, it wreaked havoc on the Caribbean island of Montserrat. Many scientists have since studied the eruption, but the internal structure of the volcano had not been well characterized until recently.
Research Spotlight: Toxic hydrocarbons measured in Gulf of Mexico
Authors: Kumar Mohi , Tretkoff Ernie
Published: October 2011

Oil contains compounds known as polycyclic aromatic hydrocarbons (PAH), which can be toxic. These compounds were released into the water during the Deepwater Horizon oil spill, which was larger than any previously studied release of oil. The impacts of the oil spill on marine life are not yet certain. Diercks et al. present initial observations of the distributions of PAH in subsurface water near the site of the Deepwater Horizon oil spill.
Research Spotlight: Separating pollution from sea spray helps aerosol‐cloud interaction studies
Authors: Kumar Mohi , Tretkoff Ernie
Published: October 2011

Aerosols suspended in the atmosphere over the ocean can typically be classified into two categories: particles from sea spray and particles from continents, the latter of which includes soot and other pollutants from anthropogenic emissions. Combined, these aerosols can influence the formation and behavior of clouds—water vapor tends to condense into droplets around these particles. However, detailed studies of how aerosols influence clouds are hampered by the fact that study regions need to be broad to get the amount of data required for statistical analysis—cloud properties in broad study regions tend to be heavily controlled by meteorological dynamics that mask the effects of aerosols on cloud formation.
Research Spotlight: Sandbar migration difficult to predict
Authors: Kumar Mohi , Tretkoff Ernie
Published: October 2011

Nearshore sandbars migrate out toward the ocean and then can move back due to the interaction of sand and waves. Pape et al. studied several data‐driven neural network models and a physically detailed model of sandbar migration to see how well they could predict sandbar migration over time scales of months to years. To investigate the effect of model complexity and the level of detail of the representation of sandbars and waves, they applied a range of different neural network architectures. They compared model results with more than 10 years of profile measurements collected daily along a 400‐meter‐long pier in Japan.
Research Spotlight: A map of global groundwater depletion
Authors: Kumar Mohi , Tretkoff Ernie
Published: October 2011

Burgeoning populations are increasing demand for water resources around the globe. In some regions where there is frequent water stress, groundwater is often used as a source of water to supplement surface water. When groundwater extraction consistently exceeds groundwater recharge through precipitation for large areas, groundwater becomes depleted. Wada et al. used a hydrological model to assess global groundwater recharge. They then subtracted estimated groundwater extraction from groundwater recharge rates to provide a global overview of groundwater depletion.
Research Spotlight: Massive release of methane from hydrates off New Zealand
Authors: Kumar Mohi , Tretkoff Ernie
Published: October 2011

Methane, a potent greenhouse gas, exists in large quantities in methane hydrates in sediments beneath the seafloor. In hydrates, methane molecules are trapped in cages of water molecules, but under some conditions these hydrates can become unstable and release methane into the ocean and atmosphere. A recent study shows that large amounts of methane may have been released from the seafloor during past peak glacial or glacial‐interglacial transition periods.
Undoped and in-situ B doped GeSn epitaxial growth on Ge by atmospheric pressure-chemical vapor deposition
Authors: Vincent B. , Gencarelli F. , Bender H. , Merckling C. , Douhard B. , Petersen D. H. , Hansen O. , Henrichsen H. H. , Meersschaut J. , Vandervorst W. , Heyns M. , Loo R. , Caymax M.
Published: October 2011

In this letter, we propose an atmospheric pressure-chemical vapor deposition technique to grow metastable GeSn epitaxial layers on Ge. We report the growth of defect free fully strained undoped and in-situ B doped GeSn layers on Ge substrates with Sn contents up to 8%. Those metastable layers stay fully strained after 30 min anneal in N2 at 500 °C; Ge-Sn interdiffusion is seen at 500 °C but not at lower temperature. B is 100% active in the in-situ GeSn:B layers up to a concentration of 1.7 × 1019 cm−3. GeSn:B provides slightly lower Hall hole mobility values than in pure p-type Ge especially for low B concentrations.
Robust conductance of dumbbell molecular junctions with fullerene anchoring groups
Authors: Markussen Troels , Settnes Mikkel , Thygesen Kristian S.
Published: October 2011

The conductance of a molecular wire connected to metallic electrodes is known to be sensitive to the atomic structure of the molecule-metal contact. This contact is to a large extent determined by the anchoring group linking the molecular wire to the metal. It has been found experimentally that a dumbbell construction with C60 molecules acting as anchors yields more well-defined conductances as compared to the widely used thiol anchoring groups. Here, we use density functional theory to investigate the electronic properties of this dumbbell construction. The conductance is found to be stable against variations in the detailed bonding geometry and in good agreement with the experimental value of \documentclass[12pt]{minimal}\begin{document}$\text{G}=3\times 10^{-4}\,\text{G}_0$\end{document}G=3×10−4G0. Electron tunneling across the molecular bridge occurs via the lowest unoccupied orbitals of C60 which are pinned close to the Fermi energy due to partial charge transfer. Our findings support the original motivation to achieve conductance values more stable towards changes in the structure of the molecule-metal contact leading to larger reproducibility in experiments.
Influence of dot size and annealing on the magnetic properties of large-area L1-FePt nanopatterns
Authors: Bublat T. , Goll D.
Published: October 2011

Hard magnetic L10-FePt nanopatterns composed of a regular arrangement of single-domain nanodots with out-of-plane texture and dot sizes between 40 nm and 100 nm have been fabricated over an area of 4 mm2 from continuous epitaxially grown L10-Fe51Pt49 films by ultraviolet nanoimprint lithography combined with inductively coupled plasma reactive Ar-ion etching. Whereas the dot size within the dot size range investigated according to superconducting quantum interference device (SQUID) magnetometry has been found to have no significant influence on the magnetic properties, the magnetic properties and magnetization reversal mechanism significantly depend on the structural morphology and shape of the nanodots which change during a post-annealing process at elevated temperatures according to high-resolution TEM investigations from crown-shaped dots with a gradually deteriorated surface region of several nm to curved dots of pure L10-FePt. The different morphology of the nanodots results for the as-etched state in smaller coercivity values (1.30 T – 1.66 T at RT) and a less strong temperature dependence of the coercivity in the temperature range of 40 K – 350 K compared to the post-annealed state (4.37 T – 4.56 T at RT). As the morphology of the as-etched dots has been found to resemble the morphology of a phase graded composite particle magnetization reversal can be attributed to a domain wall induced process (microstructural parameter α < 0.15). In contrast, for the post-annealed dots of pure L10-FePt magnetization reversal takes place by a uniform nucleation process (microstructural parameter α > 0.79).
Independent modulation of the kinase and polo-box activities of Cdc5 protein unravels unique roles in the maintenance of genome stability
Authors: Ratsima Hery , Ladouceur Anne-Marie , Pascariu Mirela , Sauvé Véronique , Salloum Zeina , Maddox Paul S. , D'Amours Damien
Published: October 2011

Polo-like kinases (PLKs) are evolutionarily conserved kinases essential for cell cycle regulation. These kinases are characterized by the presence of a C-terminal phosphopeptide-interaction domain, the polo-box domain (PBD). How the functional domains of PLKs work together to promote cell division is not understood. To address this, we performed a genetic screen to identify mutations that independently modulate the kinase and PBD activities of yeast PLK/Cdc5. This screen identified a mutagenic hotspot in the F-helix region of Cdc5 kinase domain that allows one to control kinase activity in vivo. These mutations can be systematically engineered into other major eukaryotic cell cycle kinases to similarly regulate their activity in live cells. Here, using this approach, we show that the kinase activity of Cdc5 can promote the execution of several stages of mitosis independently of PBD activity. In particular, we observe that the activation of Cdc14 and execution of mitotic exit are uniquely sensitive to the modulation of Cdc5 kinase activity. In contrast, PBD-defective mutants are capable of completing mitosis but are unable to maintain spindle pole body integrity. Consistent with this defect, PBD-deficient cells progressively double the size of their genome and ultimately lose genome integrity. Collectively, these results highlight the specific contributions of Cdc5 functional domains to cell division and reveal unexpected mechanisms controlling spindle pole body behavior and genome stability.
Continuous dental replacement in a hyper-chisel tooth digging rodent
Authors: Gomes Rodrigues Helder , Marangoni Pauline , Šumbera Radim , Tafforeau Paul , Wendelen Wim , Viriot Laurent
Published: October 2011

Contrary to their reptilian ancestors, which had numerous dental generations, mammals are known to usually develop only two generations of teeth. However, a few mammal species have acquired the ability to continuously replace their dentition by the constant addition of supernumerary teeth moving secondarily toward the front of the jaw. The resulting treadmill-like replacement is thus horizontal, and differs completely from the vertical dental succession of other mammals and their extinct relatives. Despite the developmental implications and prospects regarding the origin of supernumerary teeth, this striking innovation remains poorly documented. Here we report another case of continuous dental replacement in an African rodent,
Heliophobius argenteocinereus
, which combines this dental system with the progressive eruption of high-crowned teeth. The escalator-like mechanism of
Heliophobius
constitutes an original adaptation to hyper-chisel tooth digging involving high dental wear. Comparisons between
Heliophobius
and the few mammals that convergently acquired continuous dental replacement reveal that shared inherited traits, including dental mesial drift, delayed eruption, and supernumerary molars, comprise essential prerequisites to setting up this dental mechanism. Interestingly, these dental traits are present to a lesser extent in humans but are absent in mouse, the usual biological model. Consequently,
Heliophobius
represents a suitable model to investigate the molecular processes leading to the development of supernumerary teeth in mammals, and the accurate description of these processes could be a significant advance for further applications in humans, such as the regeneration of dental tissues.
Cap-snatching mechanism in yeast L-A double-stranded RNA virus
Authors: Fujimura Tsutomu , Esteban Rosa
Published: October 2011

The 5′ cap structure (m
7
GpppX-) is an essential feature of eukaryotic mRNA required for mRNA stability and efficient translation. Influenza virus furnishes its mRNA with this structure by a cap-snatching mechanism, in which the viral polymerase cleaves host mRNA endonucleolytically 10–13 nucleotides from the 5′ end and utilizes the capped fragment as a primer to synthesize viral transcripts. Here we report a unique cap-snatching mechanism by which the yeast double-stranded RNA totivirus L-A furnishes its transcript with a cap structure derived from mRNA. Unlike influenza virus, L-A transfers only m
7
Gp from the cap donor to the 5′ end of the viral transcript, thus preserving the 5′ α- and β-phosphates of the transcript in the triphosphate linkage of the final product. This in vitro capping reaction requires His154 of the coat protein Gag, a residue essential for decapping of host mRNA and known to form m
7
Gp-His adduct. Furthermore, the synthesis of capped viral transcripts in vivo and their expression were greatly compromised by the Arg154 mutation, indicating the involvement of Gag in the cap-snatching reaction. The overall reaction and the structure around the catalytic site in Gag resemble those of guanylyltransferase, a key enzyme of cellular mRNA capping, suggesting convergent evolution. Given that Pol of L-A is confined inside the virion and unable to access host mRNA in the cytoplasm, the structural protein Gag rather than Pol catalyzing this unique cap-snatching reaction exemplifies the versatility as well as the adaptability of eukaryotic RNA viruses.
Overexpression of the maizeCorngrass1microRNA prevents flowering, improves digestibility, and increases starch content of switchgrass
Authors: Chuck George S. , Tobias Christian , Sun Lan , Kraemer Florian , Li Chenlin , Dibble Dean , Arora Rohit , Bragg Jennifer N. , Vogel John P. , Singh Seema , Simmons Blake A. , Pauly Markus , Hake Sarah
Published: October 2011

Biofuels developed from biomass crops have the potential to supply a significant portion of our transportation fuel needs. To achieve this potential, however, it will be necessary to develop improved plant germplasm specifically tailored to serve as energy crops. Liquid transportation fuel can be created from the sugars locked inside plant cell walls. Unfortunately, these sugars are inherently resistant to hydrolytic release because they are contained in polysaccharides embedded in lignin. Overcoming this obstacle is a major objective toward developing sustainable bioenergy crop plants. The maizeCorngrass1(Cg1) gene encodes a microRNA that promotes juvenile cell wall identities and morphology. To test the hypothesis that juvenile biomass has superior qualities as a potential biofuel feedstock, theCg1gene was transferred into several other plants, including the bioenergy cropPanicum virgatum(switchgrass). Such plants were found to have up to 250% more starch, resulting in higher glucose release from saccharification assays with or without biomass pretreatment. In addition, a complete inhibition of flowering was observed in both greenhouse and field grown plants. These results point to the potential utility of this approach, both for the domestication of new biofuel crops, and for the limitation of transgene flow into native plant species.
Locating a mitochondrial scaffold on the map
Authors: Short Ben
Published: October 2011

A high-density genetic interaction map reveals a complex that organizes the mitochondrial inner membrane.
A mitochondrial-focused genetic interaction map reveals a scaffold-like complex required for inner membrane organization in mitochondria
Authors: Hoppins Suzanne , Collins Sean R. , Cassidy-Stone Ann , Hummel Eric , DeVay Rachel M. , Lackner Laura L. , Westermann Benedikt , Schuldiner Maya , Weissman Jonathan S. , Nunnari Jodi
Published: October 2011

To broadly explore mitochondrial structure and function as well as the communication of mitochondria with other cellular pathways, we constructed a quantitative, high-density genetic interaction map (the MITO-MAP) in Saccharomyces cerevisiae. The MITO-MAP provides a comprehensive view of mitochondrial function including insights into the activity of uncharacterized mitochondrial proteins and the functional connection between mitochondria and the ER. The MITO-MAP also reveals a large inner membrane–associated complex, which we term MitOS for mitochondrial organizing structure, comprised of Fcj1/Mitofilin, a conserved inner membrane protein, and five additional components. MitOS physically and functionally interacts with both outer and inner membrane components and localizes to extended structures that wrap around the inner membrane. We show that MitOS acts in concert with ATP synthase dimers to organize the inner membrane and promote normal mitochondrial morphology. We propose that MitOS acts as a conserved mitochondrial skeletal structure that differentiates regions of the inner membrane to establish the normal internal architecture of mitochondria.
Involvement of interleukin-21 in the regulation of colitis-associated colon cancer
Authors: Stolfi Carmine , Rizzo Angelamaria , Franzè Eleonora , Rotondi Angela , Fantini Massimo Claudio , Sarra Massimiliano , Caruso Roberta , Monteleone Ivan , Sileri Pierpaolo , Franceschilli Luana , Caprioli Flavio , Ferrero Stefano , MacDonald Thomas T. , Pallone Francesco , Monteleone Giovanni
Published: October 2011

Chronic inflammation is a major driving force in the development of cancer in many tissues, but the array of factors involved in this neoplastic transformation are not well understood. We have investigated the role of interleukin (IL)-21 in colitis-associated colon cancer (CAC), as this cytokine is overexpressed in the gut mucosa of patients with ulcerative colitis (UC), a chronic inflammatory disease associated with colon cancer. IL-21 was increased in the gut of patients with UC-associated colon cancer, and in mice with CAC induced by azoxymethane (AOM) and dextran sulfate sodium (DSS). After AOM+DSS treatment, IL-21 KO mice showed reduced mucosal damage, reduced infiltration of T cells, and diminished production of IL-6 and IL-17A. IL-21–deficient mice also developed fewer and smaller tumors compared with wild-type (WT) mice. Absence of IL-21 reduced signal transducer and activator of transcription 3 activation in tumor and stromal cells. Administration of a neutralizing IL-21 antibody to WT mice after the last DSS cycle decreased the colonic T cell infiltrate and the production of IL-6 and IL-17A and reduced the number of tumors. These observations indicate that IL-21 amplifies an inflammatory milieu that promotes CAC, and suggest that IL-21 blockade may be useful in reducing the risk of UC-associated colon cancer.
A moment estimate of the derivative process in rough path theory
Authors: Inahama Yuzuru
Published: October 2011

In this paper we prove that the derivative process of a rough differential equation driven by a Brownian rough path has finite

L
r

L^r

-moment for any

r
≥
1

r \ge 1

. This kind of problem is easy in the usual SDE theory, thanks to Burkholder-Davis-Gundy’s inequality. In the context of rough path theory, however, it does not seem so obvious.