bluuebunny/crossref_metadata_2025 huggingface dataset:
American Cities and American Political Science—a Look at Thick Injustice
Authors: Miller Jody
Published: August 2012

The back cover of Clarissa Rile Hayward and Todd Swanstrom'sJustice and the American Metropolisconcisely lays out a central challenge of contemporary politics: “Today's American cities and suburbs are the sites of ‘thick injustice’—unjust power relations that are deeply and densely concentrated as well as opaque and seemingly intractable. Thick injustice is hard to see, to assign responsibility for, and to change.” The fact that the topic of “urban politics” is not a major theme of political science scholarship both reflects and exacerbates this challenge. And so we have decided to invite a diverse group of social scientists to discuss the book in light of the very big question that it poses: How do American cities look when assessed in terms of their “justice” (or “injustice”), and how might they look if they were assessed in these terms more seriously? In considering this question, discussants have also been asked to consider a related question: How does Americanpolitical sciencelook when assessed in terms of the extent to which it takes the question of urban justice and injustice seriously?—Jeffrey C. Isaac, Editor
Moved to Action: Motivation, Participation, and Inequality in American Politics. By Hahrie C. Han. Stanford: Stanford University Press, 2009. 208p. $50.00 cloth, $19.95 paper.
Authors: Weldon S. Laurel
Published: August 2012

This excellent book explores how and why people participate in politics, focusing mostly on those without the educational, financial, and civic resources that enable democratic participation in the United States. How is it, Hahrie Han asks, that a large, underresourced population returned to New Orleans against great odds to vote in a mayoral election? Han problematizes the received wisdom about political participation, bringing new attention to the seemingly intractable problem of political inequality in the United States. How did these people manage to come from out of town, many of them busing in and out on the same day, to vote in a municipal election? If we find the answer to this question, we may discover new ways to expand political participation in the United States, particularly among those populations that seem to be the most difficult to pull into the democratic decision-making process.
Response to Erik Kuhonta's review of Mobilizing Restraint: Democracy and Industrial Conflict in Post-Reform South Asia
Authors: Teitelbaum Emmanuel
Published: August 2012

To what extent does Mobilizing Restraint provide insights that are useful to the study of developing countries beyond South Asia? This question deserves serious attention, but in raising doubts about whether my study has broader applicability, Erik Kuhonta does not engage key arguments in the book as well as much of the empirical evidence that I present to support them.
Race in America
Authors: Sirianni Carmen
Published: August 2012

Both the plight of African American young people and their feelings and thoughts about this plight are major issues of concern in U.S. politics. In 2003, the Black Youth Project was launched, with funding by the Ford Foundation and the Robert Wood Johnson Foundation, to promote both social scientific analysis and public understanding of these issues (the project has an innovative and engaging Website that can be accessed at http://www.blackyouthproject.com/). Cathy J. Cohen is the principal investigator of the project and, in Democracy Remixed, she draws upon a new national survey of black youth to offer a mixed-method empirical description and theoretical analysis of “black youth and the future of American politics.” In this symposium, a diverse group of political and social scientists have been asked to critically assess the book's account and to comment more broadly on the importance of black youth to the future of American politics.—Jeffrey C. Isaac, Editor
Privatization, Marketization, and Neoliberalism—The Political Dynamics of Post-Katrina New Orleans
Authors: Coyne Christopher J.
Published: August 2012

Hurricane Katrina was a “disaster” both “natural” and “social.” The storm destroyed a major American city that, like most American cities, was already the site of great inequality and vulnerability. It also dramatically put to the test both the logistical capabilities and the political responsibilities of national, state, and local governmental institutions. The Neoliberal Deluge: Hurricane Katrina, Late Capitalism, and the Remaking of New Orleans is an important collection of essays on the dynamics of “remaking New Orleans” and the limits of that effort. We have thus asked a diverse group of political scientists to review the book, and at the same time to treat it as an opportunity to reflect on two related questions: 1) What are the most important economic, cultural, and political dimensions of the crisis precipitated by Katrina, both for New Orleans and for US cities more generally? 2) What resources does political science as a discipline possess to help us understand these issues, and can political science as a discipline do a better job on this score?—Jeffrey C. Issac, Editor
Does the US Media Have a Liberal Bias?
Authors: Rosenblum Nancy L.
Published: August 2012

In Left Turn: How Liberal Bias Distorts The American Mind, Tim Groseclose argues that media effects play a crucial role in American politics. His case rests on three arguments: (1) that journalists tend overwhelmingly to be liberal rather than conservative; (2) that their innate political bias slants their views in empirically measurable ways; and (3) that this bias fundamentally shapes American politics, by bringing US citizens further to the left than they would naturally be. According to Groseclose, in a world where media bias did not exist, American citizens would on average hold views close to those of Ben Stein or Bill O'Reilly. In such a world, John McCain would have defeated Barack Obama by a popular vote margin of 56%—42% in the 2008 presidential election.

In making these claims, Groseclose draws on his own research, and on recent media scholarship by both political scientists and economists, making the broader claim that peer-reviewed social science—which seeks to deal with problems such as endogeneity and selection bias—should be the starting point for public arguments about the role of the media. His book, then, is clearly an effort to bring social scientific arguments into mainstream debates. Groseclose makes no secret of his conservative political leanings—but recent books from left-leaning political scientists such as Jacob Hacker and Paul Pierson are equally unapologetic. It is at least plausible that political scientists' typical unwillingness to engage directly in political arguments has weakened the discipline's capacity for public engagement.

In this symposium a diverse group of contributors have been invited to engage with Groseclose's arguments in ways that bring together specific empirical and/or theoretical points and arguments aimed at the broader “political science public sphere” that Perspectives on Politics seeks to nurture. Contributors were asked to consider these five questions: (1): How do we best measure media effects? (2): If media bias exists, what are its plausible sources? (3): Can one use work on media effects to determine what people's views would be in the absence of such bias? (4): Do you agree that American politics is insufficiently representative, and if so what do you consider the primary sources of this problem? (5): What kinds of political and/or media institutions or practices might enhance democratic discourse?—Henry Farrell, Associate Editor
Does the US Media Have a Liberal Bias?
Authors: Gross Justin H. , Shalizi Cosma Rohilla , Gelman Andrew
Published: August 2012

InLeft Turn: How Liberal Bias Distorts The American Mind,Tim Groseclose argues that media effects play a crucial role in American politics. His case rests on three arguments: (1) that journalists tend overwhelmingly to be liberal rather than conservative; (2) that their innate political bias slants their views in empirically measurable ways; and (3) that this bias fundamentally shapes American politics, by bringing US citizens further to the left than they would naturally be. According to Groseclose, in a world where media bias did not exist, American citizens would on average hold views close to those of Ben Stein or Bill O'Reilly. In such a world, John McCain would have defeated Barack Obama by a popular vote margin of 56%—42% in the 2008 presidential election.

In making these claims, Groseclose draws on his own research, and on recent media scholarship by both political scientists and economists, making the broader claim that peer-reviewed social science—which seeks to deal with problems such as endogeneity and selection bias—should be the starting point for public arguments about the role of the media. His book, then, is clearly an effort to bring social scientific arguments into mainstream debates. Groseclose makes no secret of his conservative political leanings—but recent books from left-leaning political scientists such as Jacob Hacker and Paul Pierson are equally unapologetic. It is at least plausible that political scientists' typical unwillingness to engage directly in political arguments has weakened the discipline's capacity for public engagement.

In this symposium a diverse group of contributors have been invited to engage with Groseclose's arguments in ways that bring together specific empirical and/or theoretical points and arguments aimed at the broader “political science public sphere” thatPerspectives on Politicsseeks to nurture. Contributors were asked to consider these five questions: (1): How do we best measure media effects? (2): If media bias exists, what are its plausible sources? (3): Can one use work on media effects to determine what people's views would be in the absence of such bias? (4): Do you agree that American politics is insufficiently representative, and if so what do you consider the primary sources of this problem? (5): What kinds of political and/or media institutions or practices might enhance democratic discourse?—Henry Farrell, Associate Editor
Does the US Media Have a Liberal Bias?
Authors: Nyhan Brendan
Published: August 2012

In Left Turn: How Liberal Bias Distorts The American Mind, Tim Groseclose argues that media effects play a crucial role in American politics. His case rests on three arguments: (1) that journalists tend overwhelmingly to be liberal rather than conservative; (2) that their innate political bias slants their views in empirically measurable ways; and (3) that this bias fundamentally shapes American politics, by bringing US citizens further to the left than they would naturally be. According to Groseclose, in a world where media bias did not exist, American citizens would on average hold views close to those of Ben Stein or Bill O'Reilly. In such a world, John McCain would have defeated Barack Obama by a popular vote margin of 56%—42% in the 2008 presidential election.

In making these claims, Groseclose draws on his own research, and on recent media scholarship by both political scientists and economists, making the broader claim that peer-reviewed social science—which seeks to deal with problems such as endogeneity and selection bias—should be the starting point for public arguments about the role of the media. His book, then, is clearly an effort to bring social scientific arguments into mainstream debates. Groseclose makes no secret of his conservative political leanings—but recent books from left-leaning political scientists such as Jacob Hacker and Paul Pierson are equally unapologetic. It is at least plausible that political scientists' typical unwillingness to engage directly in political arguments has weakened the discipline's capacity for public engagement.

In this symposium a diverse group of contributors have been invited to engage with Groseclose's arguments in ways that bring together specific empirical and/or theoretical points and arguments aimed at the broader “political science public sphere” that Perspectives on Politics seeks to nurture. Contributors were asked to consider these five questions: (1): How do we best measure media effects? (2): If media bias exists, what are its plausible sources? (3): Can one use work on media effects to determine what people's views would be in the absence of such bias? (4): Do you agree that American politics is insufficiently representative, and if so what do you consider the primary sources of this problem? (5): What kinds of political and/or media institutions or practices might enhance democratic discourse?—Henry Farrell, Associate Editor
The Institutional Imperative: The Politics of Equitable Development in Southeast Asia. By Erik Martinez Kuhonta. Stanford: Stanford University Press, 2011. 368p. $50.00.
Authors: Teitelbaum Emmanuel
Published: August 2012

In his book, Erik Kuhonta advances an institutional theory of equitable development. He argues that an institutionalized party helps to promote social and human development by privileging public over private interests and by promoting programmatic politics rather than clientelistic exchange. A party is fully institutionalized when it is autonomous, coherent, and organizationally complex, but is rooted in society in a way that enables it to address the needs of the poor (pp. 23–24). To test his argument, Kuhonta draws on evidence from two sets of paired comparisons. The primary comparison is of Malaysia and Thailand, and in a separate chapter, he extends the argument by comparing the Philippines and Vietnam.
Response to Emmanuel Teitelbaum's review of The Institutional Imperative: The Politics of Equitable Development in Southeast Asia
Authors: Kuhonta Erik Martinez
Published: August 2012

Emmanuel Teitelbaum raises some very valuable points regarding my book. First, on the issue of regime type, I argued that the central variables that affect equitable development are the character of institutions, especially institutionalized political parties and cohesive state structures, and pragmatic ideology—not regime type. While one conclusion that emerges from the study is that illiberal regimes (Malaysia and Vietnam) have done better than liberal regimes (Thailand and the Philippines), I do not argue that illiberalism is a necessary variable for equitable development. The record across the developing world shows that many authoritarian regimes have very dismal economic outcomes. My argument hinges on the power, responsiveness, and capacity of institutions.
Response to Ben Berger's review of Hiring and Firing Public Officials: Rethinking the Purpose of Elections
Authors: Buchler Justin
Published: August 2012

I am encouraged by Ben Berger's reaction to my book, and hopeful that other readers will be as open-minded. Of course, the drawback of Berger's Cassandra comparison is that if it is apt, that will not be the case. Similarly, the drawback of any attempt at a paradigm shift in Kuhn's terms is that nearly every attempt fails, and it is difficult for the author himself to distinguish a negative reaction motivated by philosophical conservatism from a negative reaction motivated by intrinsic weakness in the unconventional argument itself.
Response to Justin Buchler's review of Attention Deficit Democracy: The Paradox of Civic Engagement
Authors: Berger Ben
Published: August 2012

Rational choice theorists and political theorists have much to gain in open exchange, as shown in Jon Elster's masterly analyses of Alexis de Tocqueville (1993, 2009) and Russell Hardin's engagement with David Hume (2009). Thus, I appreciate Justin Buchler's insights into my book, and since my points of agreement with him will be obvious, I will focus on the areas of contention.
Response to John Ferejohn's review of Reputation and Power: Organizational Image and Pharmaceutical Regulation at the FDA
Authors: Carpenter Daniel
Published: August 2012

How do republicanism and regulation coexist? How does the politics of administrative constitutionalism constrain and enable the action of regulators in their governance of economic, political, and scientific realms? How can an adaptive republic strike a set of appropriate, lawful, representative, and efficient balances among the contending interests in regulatory policy? These are what I take to be the central questions raised by John Ferejohn in his perceptive review of Reputation and Power. His answer, as applied to US pharmaceutical regulation, is not intended to be definitive but aims, rather, to pose a set of hypotheses and questions.
A Perspective on Perspectives
Authors: Isaac Jeffrey C.
Published: August 2012

The most important thing any scholarly journal can do is to publish scholarly research and writing that is both excellent and intellectually engaging. Since it hit the ground running in 2002, Perspectives on Politics has been committed to the highest standards of scholarly publication. At the same time, from its inception Perspectives has been a journal with a difference, seeking to combine scholarly excellence with relevance and readability, and to feature a wide range of formats for and perspectives on the serious study of politics. For the past ten years Perspectives has thus served as an important public sphere for political science in general and especially for the American Political Science Association.
Disaster, Inc.: Privatization and Post-Katrina Rebuilding in New Orleans
Authors: Gotham Kevin Fox
Published: August 2012

This paper examines the problems and limitations of the privatization of federal and local disaster recovery policies and services following the Hurricane Katrina disaster. The paper discusses the significance of the Homeland Security Act of 2002 in accelerating efforts to devolve and privatize emergency management functions; the reorganization of the Federal Emergency Management Agency (FEMA) as a service purchaser and arranger; and the efforts by the New Orleans city government to contract out disaster recovery activities to private firms. I situate and explain these three developments in the context of recent trends toward the neoliberalization of state activities, including the privatization and devolution of policy implementation to private firms and non-governmental organizations. On both the federal and local levels, inadequate contract oversight and lack of cost controls provided opportunities for private contractors to siphon public resources and exploit government agencies to further their profiteering interests and accumulation agendas. This article demonstrates how the privatization of emergency management services and policy constitutes a new regulatory project in which the state's role has shifted away from providing aid to disaster victims and toward the management and coordination of services delivered by private contractors.
Aggregates Unseen: Imagining Post-Katrina New Orleans
Authors: Johnson James
Published: August 2012

Photography, understood as a technology for amplifying imagination, affords a useful tool for coming to terms with the massive forced migration caused by the Katrina catastrophe. Specifically, photographic projects by Robert Polidori and Richard Misrach reveal the exigencies of communicating in the wake of the disaster.
Shock barometer using cathodoluminescence of alkali feldspar
Authors: Kayama Masahiro , Nishido Hirotsugu , Sekine Toshimori , Nakazato Tadahiro , Gucsik Arnold , Ninagawa Kiyotaka
Published: August 2012

Color cathodoluminescence (CL) images of unshocked and experimentally shocked sanidine at pressures up to 40.1 GPa showed red‐violet emission below 20.0 GPa and blue emission above 20.0 GPa. The phases in these shock‐recovered samples were identified as crystalline feldspar for red‐violet emitting areas and as diaplectic feldspar glass for blue emitting ones by micro‐Raman spectroscopy. CL spectra of these shocked sanidine have emissions at ∼330, ∼380 and 400–420 nm of which intensities increase with an increase in shock pressure. Similar UV‐blue emissions were found in alkali feldspar and the glass in Martian meteorites and Ries crater impactite. The deconvolution of these CL spectra provides the emission component at 2.948 eV assigned to shock‐induced defect center, where this intensity correlates linearly with peak shock‐induced pressure on sanidine, with little dependence on composition and structure. The correlation gives quantitative values of the shock pressures experienced by the feldspar, resulting in estimated shock pressures of Martian meteorites and Ries crater impactite. The CL intensity of feldspar has a potential for a universal shock barometer with high spatial resolution (∼1μm) and in a wide pressure range (theoretically ∼4.5–40.1 GPa). This leads to a breakthrough in understanding the impact histories on Earth, Moon, and Mars.
Short wavelength heterogeneity in the Galápagos plume: Evidence from compositionally diverse basalts on Isla Santiago
Authors: Gibson S. A. , Geist D. G. , Day J. A. , Dale C. W.
Published: August 2012

Analyses of basalts from the Galápagos archipelago and adjacent spreading center have shown that the underlying mantle plume is isotopically heterogeneous over length scales of 10s to 100s of km. We show that the convecting mantle is also compositionally heterogeneous on smaller length scales (kms). Our evidence comes from recent small‐volume mildly alkaline and tholeiitic basalts on Isla Santiago, central Galápagos. Flows from volcanic vents <5 km apart are homogeneous in terms of incompatible‐trace element and isotopic ratios but inter‐vent variations in these ratios are large, such that Santiago basalts display some of the most extensive ranges known for any Galápagos island. Geochemical indexes of depth of melting correlate with an eastward decrease in geophysical estimates of lithospheric thickness–from 55 to 43 km over a ∼10 km horizontal distance beneath Isla Santiago–suggesting that melts have not undergone significant lateral transport in the underlying crust. This lithospheric ‘step’ below the center of the island generally results in a greater proportion of enriched mantle melts contributing to basalts from west Santiago, than to those in the east, due to less melting of more depleted mantle as the plume upwells beneath thicker lithosphere. Nevertheless, the sporadic occurrence of isotopically enriched flows with low [Sm/Yb]n, and more isotopically depleted compositions with elevated [Sm/Yb]n, across Santiago suggests that portions of the underlying Galápagos plume are compositionally heterogeneous in terms of enriched and depleted reservoirs over short length scales (kilometers). In this respect the Galápagos mantle plume is similar to plumes beneath Hawaii and Canary Islands.
Major element variations in Hawaiian shield lavas: Source features and perspectives from global ocean island basalt (OIB) systematics
Authors: Jackson Matthew G. , Weis Dominique , Huang Shichun
Published: August 2012

Among volcanic hot spots globally, Hawaii has the highest magma flux, yet there is significant controversy surrounding the composition of the mantle sourcing Hawaiian lavas. In order to place constraints on the source lithologies of Hawaiian lavas, we explore relationships between major elements and radiogenic isotopes in tholeiitic, shield‐building lavas. Olivine‐fractionation corrected lava compositions reveal clear trends between radiogenic isotopes and major elements. Individual data points exhibit remarkable trends and there is no need to average the data by volcano. Data form arrays that are anchored by Koolau lava at one end (with high 87Sr/86Sr, 187Os/188Os, SiO2, and Na2O/TiO2, and low 143Nd/144Nd, 206Pb/204Pb, TiO2, CaO and CaO/Al2O3) and by Kea and Loihi lavas at the other (with low 87Sr/86Sr, 187Os/188Os, SiO2, and Na2O/TiO2, and high 143Nd/144Nd, 206Pb/204Pb, TiO2, CaO and CaO/Al2O3). FeOtotal, Al2O3 and Na2O concentrations do not correlate with radiogenic isotopes. The Hawaiian data set exhibits correlations that mirror the best correlations between major elements and radiogenic isotope in the global ocean island basalt (OIB) database. We suggest that the mechanism driving the correlations in Hawaii illustrates, in microcosm, a larger global process that generates major element variability in mantle plumes. Like the global arrays, the Hawaiian lavas with radiogenic Pb and SiO2‐poor lavas are sourced by a SiO2‐poor mafic component (pyroxenite) admixed with peridotite, while Hawaiian lavas with unradiogenic Pb and high SiO2 are sourced by a SiO2‐rich mafic component (eclogite). The variable SiO2 in the mafic component may result from different degrees of SiO2‐extraction from the slab during subduction.
Evaluating global trends (1988–2010) in harmonized multi‐satellite surface soil moisture
Authors: Dorigo Wouter , de Jeu Richard , Chung Daniel , Parinussa Robert , Liu Yi , Wagner Wolfgang , Fernández‐Prieto Diego
Published: August 2012

Global trends in a new multi‐satellite surface soil moisture dataset were analyzed for the period 1988–2010. 27% of the area covered by the dataset showed significant trends (p = 0.05). Of these, 73% were negative and 27% positive. Subtle drying trends were found in the Southern US, central South America, central Eurasia, northern Africa and the Middle East, Mongolia and northeast China, northern Siberia, and Western Australia. The strongest wetting trends were found in southern Africa and the subarctic region. Intra‐annual analysis revealed that most trends are not uniform among seasons. The most prominent trend patterns in remotely sensed surface soil moisture were also found in GLDAS‐Noah and ERA Interim modeled surface soil moisture and GPCP precipitation, lending confidence to the obtained results. The relationship with trends in GIMMS‐NDVI appeared more complex. In areas of mutual disagreement more research is needed to identify potential deficiencies in models and/or remotely sensed products.
Evidence of nonspheroidal behavior in millimeter‐wavelength radar observations of snowfall
Authors: Leinonen J. , Kneifel S. , Moisseev D. , Tyynelä J. , Tanelli S. , Nousiainen T.
Published: August 2012

Recent modeling results have indicated that, in general, idealized homogeneous spheroidal models of ice crystals and snowflakes cannot consistently describe radar backscattering from snowfall when the radar wavelengths are on the order of the snowflake size. In this paper, we provide empirical evidence supporting this prediction by analyzing collocated airborne radar measurements at 13.4 GHz, 35.6 GHz and 94 GHz. The analysis is performed by applying a recently developed method making use of two simultaneously measured dual‐frequency ratios, allowing one to distinguish between the multifrequency backscattering behavior of detailed aggregate snow models and that of homogeneous spheroids. We demonstrate that in some naturally occurring cases, detailed snowflake models, which account for their complex structure, are required to describe backscattering by these particles in a manner that is consistent over multiple wavelengths. This implies that the spheroidal approximation is not always adequate as a snowflake shape model in radar retrievals at this wavelength range.
A study on the low‐altitude clouds over the Southern Ocean using the DARDAR‐MASK
Authors: Huang Yi , Siems Steven T. , Manton Michael J. , Protat Alain , Delanoë Julien
Published: August 2012

A climatology of the thermodynamic phase of the clouds over the Southern Ocean (40–65°S,100–160°E) has been constructed with the A‐Train merged data product DARDAR‐MASK for the four‐year period 2006–2009 during Austral winter and summer. Low‐elevation clouds with little seasonal cycle dominate this climatology, with the cloud tops commonly found at heights less than 1 km. Such clouds are problematic for the DARDAR‐MASK in that the Cloud Profiling Radar (CPR) of CloudSat is unable to distinguish returns from the lowest four bins (heights up to 720–960 m), and the CALIOP lidar of CALIPSO may suffer from heavy extinction. The CPR is further limited for all of the low‐altitude clouds (tops below 3 km) as they are predominantly in the temperature range from 0°C to −20°C, where understanding the CPR reflectivity becomes difficult due to the unknown thermodynamic phase. These shortcomings are seen to flow through to the merged CloudSat‐CALIPSO product. A cloud top phase climatology comparison has been made between CALIPSO, the DARDAR‐MASK and MODIS. All three products highlight the extensive presence of supercooled liquid water over the Southern Ocean, particularly during summer. The DARDAR‐MASK recorded substantially more ice at cloud tops as well as mixed‐phase in the low‐elevation cloud tops in comparison to CALIPSO and MODIS. Below the cloud top through the body of the cloud, the DARDAR‐MASK finds ice to be dominant at heights greater than 1 km, especially once the lidar signal is attenuated. The limitations demonstrated in this study highlight the continuing challenge that remains in better defining the energy and water budget over the Southern Ocean.
On the mixing‐driven formation of the Extratropical Transition Layer (ExTL)
Authors: Konopka Paul , Pan Laura L.
Published: August 2012

We present a case study on the formation and structure of the Extratropical Transition Layer (ExTL) using in situ observations and a Lagrangian chemical transport model. The results show that the model with mixing parameterized from the large‐scale flow deformations well reconstructs the observed asymmetric structure of the ExTL with a deeper transition layer on the cyclonic side of the jet stream. Information from the model and observations are integrated using tracer‐tracer correlations between ozone (O3) and carbon monoxide (CO). Transport of chemical tracers from the stratospheric or tropospheric background to the ExTL through mixing is identified by the change of the CO‐O3correlation in the CO‐O3 space. The ExTL formation process simulated by the model, therefore, provides a scenario to connect the mixed air parcels to the history of mixing. An estimate of timescales of ExTL formation is made using model experiments. The results show that the fastest formation of the ExTL occurs on the isentropic levels below the subtropical jet core, e.g. around 3 weeks for 310 K, whereas at 360 K level (jet core) the formation of the ExTL needs around 3 months. Overall, this result demonstrates the important role of mixing in transport of trace gases across the tropopause.
Climatic limits on foliar growth during major droughts in the southwestern USA
Authors: Weiss Jeremy L. , Betancourt Julio L. , Overpeck Jonathan T.
Published: August 2012

Pronounced droughts during the 1950s and 2000s in the American Southwest provide an opportunity to compare mesoscale ecosystem responses to anomalously dry conditions before and during the regional warming that started in the late 1970s. This year‐round warming has produced fewer cool season freezes, losses in regional snowpack, an 8–10 day advance in spring onset, and hotter summers, all of which should affect vegetation differently across seasons and elevations. Here, we examine indices that represent climatic limits on foliar growth for both drought periods and evaluate these indices for areas that experienced tree mortality during the 2000s drought. Relative to the 1950s drought, warmer conditions during the 2000s drought decreased the occurrence of temperatures too low for foliar growth at lower elevations in winter and higher elevations in summer. Higher vapor pressure deficits (VPDs), largely driven by warmer temperatures in the more recent drought, were more limiting to foliar growth from spring through summer at lower and middle elevations. At many locations where tree mortality occurred during the 2000s drought, low‐temperature constraints on foliar growth were extremely unlimiting, whereas VPD constraints were extremely limiting from early spring through late autumn. Our analysis shows that in physiographically complex regions such as the Southwest, seasonality and elevational gradients are important for understanding vegetative responses to warming. It also suggests that continued warming will both increase the degree to which VPD limits foliar growth during future droughts and expand its reach to higher elevations and other seasons.
Thickness measurements of nanoscale brine films on silica surfaces under geologic CO2sequestration conditions using synchrotron X‐ray fluorescence
Authors: Kim Tae Wook , Tokunaga Tetsu K. , Shuman Derek B. , Sutton Stephen R. , Newville Matt , Lanzirotti Antonio
Published: August 2012

In reservoirs used for geologic CO2 sequestration, brine films remaining on mineral surfaces can influence flow, diffusion, and reactions. We have investigated how the capillary (disjoining) potential influences the thickness of a KCsI2 brine film on both smooth and rough SiO2 surfaces [root mean square roughness (Rrms), 1.6 and 330 nm, respectively], under confinement with supercritical (sc) CO2. The thicknesses of brine films coating interior surfaces of SiO2windows in a high‐pressure cell were determined through synchrotron X‐ray fluorescence of two tracer ions (I− and Cs+) at 7.8 MPa and 40°C (representative of conditions at about 0.78 km below the land surface), with scCO2as the immiscible confining fluid. The measured area‐averaged film thicknesses on the 330 nm Rrms silica surface ranged from 265 to 249 nm for capillary potentials measured within a narrow range from 0.18 to 3.7 kPa. Over this same range of potentials, film thicknesses measured on the smooth (1.6 nm Rrms) silica surface were about 2 nm, although equilibrium does not appear to have been achieved. The measured average brine film thicknesses were strongly controlled by surface roughness, with very weak variation in response to the fairly narrow range of tested capillary potentials.
Distinct cutaneous bacterial assemblages in a sampling of South American Amerindians and US residents
Authors: Blaser Martin J , Dominguez-Bello Maria G , Contreras Monica , Magris Magda , Hidalgo Glida , Estrada Isidoro , Gao Zhan , Clemente Jose C , Costello Elizabeth K , Knight Rob
Published: August 2012

The human skin harbors complex bacterial communities. Prior studies showing high inter-individual variation focused on subjects from developed countries. We therefore compared cutaneous bacterial communities of Amerindians in the Venezuelan Amazon with subjects in the United States. Forearm skin specimens were studied from healthy Amerindians in Platanillal village in Amazonas State, and from healthy persons in New York and Colorado. All skin sampling used similar swab/buffer techniques. Multiplexed V2-targeted 16S rRNA gene pyrosequencing yielded high quality sequences from 112 samples. The results show 20 phyla, with three (Proteobacteria, Firmicutes, Actinobacteria) predominating. US residents and Venezuelan Amerindians had significantly different forearm skin bacterial community compositions, with United States dominated by Propionibacterium. Among the Amerindians, there was a deep split based on bacterial community membership, with 30 and 42 samples, respectively, falling into each of the two groups, not associated with age, gender, or body mass index. One Amerindian group had diversity similar to the United States, but was dominated by Staphylococcus rather than Propionibacterium. The other Amerindian group was significantly more diverse and even than the US or the other Amerindian group, and featured a broad range of Proteobacteria. The results provide evidence that ethnicity, lifestyle and/or geography are associated with the structure of human cutaneous bacterial communities.
Ecology of uncultured Prochlorococcus clades revealed through single-cell genomics and biogeographic analysis
Authors: Malmstrom Rex R , Rodrigue Sébastien , Huang Katherine H , Kelly Libusha , Kern Suzanne E , Thompson Anne , Roggensack Sara , Berube Paul M , Henn Matthew R , Chisholm Sallie W
Published: August 2012

Prochlorococcus is the numerically dominant photosynthetic organism throughout much of the world’s oceans, yet little is known about the ecology and genetic diversity of populations inhabiting tropical waters. To help close this gap, we examined natural Prochlorococcus communities in the tropical Pacific Ocean using a single-cell whole-genome amplification and sequencing. Analysis of the gene content of just 10 single cells from these waters added 394 new genes to the Prochlorococcus pan-genome—that is, genes never before seen in a Prochlorococcus cell. Analysis of marker genes, including the ribosomal internal transcribed sequence, from dozens of individual cells revealed several representatives from two uncultivated clades of Prochlorococcus previously identified as HNLC1 and HNLC2. While the HNLC clades can dominate Prochlorococcus communities under certain conditions, their overall geographic distribution was highly restricted compared with other clades of Prochlorococcus. In the Atlantic and Pacific oceans, these clades were only found in warm waters with low Fe and high inorganic P levels. Genomic analysis suggests that at least one of these clades thrives in low Fe environments by scavenging organic-bound Fe, a process previously unknown in Prochlorococcus. Furthermore, the capacity to utilize organic-bound Fe appears to have been acquired horizontally and may be exchanged among other clades of Prochlorococcus. Finally, one of the single Prochlorococcus cells sequenced contained a partial genome of what appears to be a prophage integrated into the genome.
Bacterial diversity, community structure and potential growth rates along an estuarine salinity gradient
Authors: Campbell Barbara J , Kirchman David L
Published: August 2012

Very little is known about growth rates of individual bacterial taxa and how they respond to environmental flux. Here, we characterized bacterial community diversity, structure and the relative abundance of 16S rRNA and 16S rRNA genes (rDNA) using pyrosequencing along the salinity gradient in the Delaware Bay. Indices of diversity, evenness, structure and growth rates of the surface bacterial community significantly varied along the transect, reflecting active mixing between the freshwater and marine ends of the estuary. There was no positive correlation between relative abundances of 16S rRNA and rDNA for the entire bacterial community, suggesting that abundance of bacteria does not necessarily reflect potential growth rate or activity. However, for almost half of the individual taxa, 16S rRNA positively correlated with rDNA, suggesting that activity did follow abundance in these cases. The positive relationship between 16S rRNA and rDNA was less in the whole water community than for free-living taxa, indicating that the two communities differed in activity. The 16S rRNA:rDNA ratios of some typically marine taxa reflected differences in light, nutrient concentrations and other environmental factors along the estuarine gradient. The ratios of individual freshwater taxa declined as salinity increased, whereas the 16S rRNA:rDNA ratios of only some typical marine bacteria increased as salinity increased. These data suggest that physical and other bottom-up factors differentially affect growth rates, but not necessarily abundance of individual taxa in this highly variable environment.
Yersinia pestis infection and laboratory conditions alter flea-associated bacterial communities
Authors: Jones Ryan T , Vetter Sara M , Montenieiri John , Holmes Jennifer , Bernhardt Scott A , Gage Kenneth L
Published: August 2012

We collected Oropsylla montana from rock squirrels, Spermophilus varigatus, and infected a subset of collected fleas with Yersinia pestis, the etiological agent of plague. We used bar-tagged DNA pyrosequencing to characterize bacterial communities of wild, uninfected controls and infected fleas. Bacterial communities within Y. pestis-infected fleas were substantially more similar to one another than communities within wild or control fleas, suggesting that infection alters the bacterial community in a directed manner such that specific bacterial lineages are severely reduced in abundance or entirely eliminated from the community. Laboratory conditions also significantly altered flea-associated bacterial communities relative to wild communities, but much less so than Y. pestis infection. The abundance of Firmicutes decreased considerably in infected fleas, and Bacteroidetes were almost completely eliminated from both the control and infected fleas. Bartonella and Wolbachia were unaffected or responded positively to Y. pestis infection.
A non-B DNA can replace heptamer of V(D)J recombination when present along with a nonamer: implications in chromosomal translocations and cancer
Authors: Nishana Mayilaadumveettil , Raghavan Sathees C.
Published: August 2012

The RAG (recombination-activating gene) complex is responsible for the generation of antigen receptor diversity by acting as a sequence-specific nuclease. Recent studies have shown that it also acts as a structure-specific nuclease. However, little is known about the factors regulating this activity at the genomic level. We show in the present study that the proximity of a V(D)J nonamer to heteroduplex DNA significantly increases RAG cleavage and binding efficiencies at physiological concentrations of MgCl2. The position of the nonamer with respect to heteroduplex DNA was important, but not orientation. A spacer length of 18 bp between the nonamer and mismatch was optimal for RAG-mediated DNA cleavage. Mutations to the sequence of the nonamer and deletion of the nonamer-binding domain of RAG1 reinforced the role of the nonamer in the enhancement in RAG cleavage. Interestingly, partial mutation of the nonamer did not significantly reduce RAG cleavage on heteroduplex DNA, suggesting that even cryptic nonamers were sufficient to enhance RAG cleavage. More importantly, we show that the fragile region involved in chromosomal translocations associated with BCL2 (B-cell lymphoma 2) can be cleaved by RAGs following a nonamer-dependent mechanism. Hence our results from the present study suggest that a non-B DNA can replace the heptamer of RSS (recombination signal sequence) when present adjacent to nonamers, explaining the generation of certain chromosomal translocations in lymphoid malignancies.
Early Vocabulary Delay and Behavioral/Emotional Problems in Early Childhood: The Generation R Study
Authors: Henrichs Jens , Rescorla Leslie , Donkersloot Cootje , Schenk Jacqueline J. , Raat Hein , Jaddoe Vincent W. V. , Hofman Albert , Verhulst Frank C. , Tiemeier Henning
Published: August 2012

Purpose

The authors tested associations between (a) parent-reported temporary vs. persistent vocabulary delay and (b) parent-reported behavioral/emotional problems in a sample of 5,497 young Dutch children participating in a prospective population-based study.

Method

Mothers completed the MacArthur Communicative Development Inventory—Netherlands (Zink & Lejaegere, 2003) at age 18 months and the Language Development Survey (Rescorla, 1989) at age 30 months, with expressive vocabulary delay defined as scores in the lowest 15th age- and gender-specific percentiles. The Child Behavior Checklist (Achenbach & Rescorla, 2000) was completed by mothers when their children were age 18 months and by both parents when their children were age 36 months, from which Internalizing Problems and Externalizing Problems scores were analyzed.

Results

All analyses were adjusted for covariates. Expressive vocabulary delay at age 18 months was weakly related to Internalizing Problems scores at age 18 months as well as mother-reported Externalizing and Internalizing Problems scores at age 36 months (the latter for boys only). Expressive vocabulary delay at age 30 months was weakly associated with mother-reported Externalizing and Internalizing Problems scores (the latter for boys only) and father-reported Internalizing Problems scores. Persistent expressive vocabulary delay predicted the highest risk of mother-reported internalizing and externalizing problems at age 36 months.

Conclusion

This population-based study showed modest associations between vocabulary delay and behavioral/emotional problems detectable from 18 months onward.
Enhancing Communication Through Gesture and Naming Therapy
Authors: Caute Anna , Pring Tim , Cocks Naomi , Cruice Madeline , Best Wendy , Marshall Jane
Published: August 2012

Purpose

In this study, the authors investigated whether gesture, naming, and strategic treatment improved the communication skills of 14 people with severe aphasia.

Method

All participants received 15 hr of gesture and naming treatment (reported in a companion article [Marshall et al., 2012]). Half the group received a further 15 hr of strategic therapy, whereas the remaining 7 participants received no further input. The effects of therapy on communication were assessed with 2 novel measures. These measures required each participant to convey simple messages and narratives to his or her communication partner. In both assessments, a subset of the stimuli featured items that had been targets in gesture or naming treatment.

Results

Performance on the communication measures was stable over 2 baseline assessments but improved after gesture and naming treatment. Those participants who received additional strategic therapy made further gains on the message but not on the narrative task. Communication gains were not specific to the stimuli featuring trained items.

Conclusions

This study suggests that gesture and naming treatments can benefit interactive communication. The additional benefits of strategic therapy were less clear-cut but did have an impact on the transmission of simple messages. Gains seem to reflect the development of general communication skills rather than the use of trained gestures and/or words.
Word Learning Processes in Children With Cochlear Implants
Authors: Walker Elizabeth A. , McGregor Karla K.
Published: August 2012

Purpose

To determine whether 3 aspects of the word learning process—fast mapping, retention, and extension—are problematic for children with cochlear implants (CIs).

Method

The authors compared responses of 24 children with CIs, 24 age-matched hearing children, and 23 vocabulary-matched hearing children to a novel object noun training episode. Comprehension and production were measured immediately following training (fast mapping) as well as 1 day later (retention). Extension was measured in terms of the ability of the participants to identify new (untrained) exemplars.

Results

Compared with their hearing age-mates, children with CIs performed marginally more poorly on fast mapping as measured by the comprehension probe and more poorly on retention as measured by comprehension and production probes. The age-mates improved over the retention interval, but the children with CIs did not. Most of the children with CIs performed similarly to their age-mates on extension, but 2 children underextended, and 5 children failed to understand the task. Compared with younger vocabulary-matched peers, children with CIs did not differ at fast mapping, retention, or extension.

Conclusions

Children with CIs demonstrated deficits in word learning, with retention being especially problematic. Their learning did not differ from that of younger children with similarly sized vocabularies.
Childhood Maltreatment and Communication Development
Authors: Hwa-Froelich Deborah
Published: August 2012

Purpose: Maltreatment of children is a common and international problem. The consequences of maltreatment often are misunderstood or unknown. In this article, I will define maltreatment and explore the communication development of children with a history of maltreatment.

I reviewed the literature on children experiencing maltreatment, including articles describing the communication development of children remaining in a maltreating environment, children who were recently removed from maltreatment, children in foster care, and children adopted from orphanages. In each study, I found evidence that children who experienced maltreatment demonstrated lower language performance or poorer social knowledge than children who had not experienced maltreatment.

Conclusion: Children who have experienced abuse and/or neglect are at risk of poorer receptive, expressive, and social language development. I will discuss the clinical implications of this finding.