bluuebunny/crossref_metadata_2025 huggingface dataset:
Involvement of a Cell Wall-Associated Kinase, WAKL4, in Arabidopsis Mineral Responses
Authors: Hou Xuewen , Tong Hongyun , Selby Jessie , DeWitt Jane , Peng Xinxiang , He Zheng-Hui
Published: November 2005

The cell wall-associated receptor kinase (WAK) and WAK-like kinase (WAKL) gene family members are good candidates for physical linkers that signal between the cell wall and the cytoplasmic compartment. Previous studies have suggested that while some WAK/WAKL members play a role in bacterial pathogen and heavy-metal aluminum responses, others are involved in cell elongation and plant development. Here, we report a functional role for the WAKL4 gene in Arabidopsis (Arabidopsis thaliana) mineral responses. Confocal microscopic studies localized WAKL4-green fluorescent protein fusion proteins on the cell surfaces suggesting that, like other WAK/WAKL proteins, WAKL4 protein is associated with the cell wall. Histochemical analyses of the WAKL4 promoter fused with the β-glucuronidase reporter gene have shown that WAKL4 expression is induced by Na+, K+, Cu2+, Ni2+, and Zn2+. A transgenic line with a T-DNA insertion at 40-bp upstream of the WAKL4 start codon was characterized. While the T-DNA insertion had little effect on the WAKL4 transcript levels under normal growth conditions, it significantly altered the expression patterns of WAKL4 under various conditions of mineral nutrients. Semiquantitative and quantitative reverse transcription-PCR analyses showed that the promoter impairment abolished WAKL4-induced expression by Na+, K+, Cu2+, and Zn2+, but not by Ni2+. Whereas the WAKL4 promoter impairment resulted in hypersensitivity to K+, Na+, Cu2+, and Zn2+, it conferred a better tolerance to toxic levels of the Ni2+ heavy metal. WAKL4 was required for the up-regulation of zinc transporter genes during zinc deficiency, and the WAKL4 T-DNA insertion resulted in a reduction of Zn2+ accumulation in shoots. A WAKL4-green fluorescent protein fusion gene driven by either the WAKL4 native promoter or the 35S constitutive promoter complemented the phenotypes. Our results suggest versatile roles for WAKL4 in Arabidopsis mineral nutrition responses.
Ecotype Allelic Variation in C-to-U Editing Extent of a Mitochondrial Transcript Identifies RNA-Editing Quantitative Trait Loci in Arabidopsis
Authors: Bentolila Stéphane , Chateigner-Boutin Anne-Laure , Hanson Maureen R.
Published: November 2005

In higher plants, RNA editing is a posttranscriptional process that converts C to U in organelle mRNAs. Although RNA editing in mitochondria occurs much more frequently than in chloroplasts, editing of exogenously supplied RNA substrates in vitro and in organello has shown that editing in the two organelles shares some common features. In particular, the 20 nucleotides upstream of the editing site play an important role in specifying the C to be edited. Biochemical approaches have allowed the identification of features of cis-sequences necessary for RNA editing to occur, but have failed to identify any of the components of the mitochondrial editing machinery. In order to implement a genetic approach for identification of editing factors, we have identified a polymorphism in the editing efficiency of a mitochondrial site between two ecotypes of Arabidopsis (Arabidopsis thaliana), Columbia (Col) and Landsberg erecta (Ler). In rosette leaves, an editing site within the ccb206 mitochondrial gene is more highly edited in Col than in Ler. Depending on the development stage and tissue analyzed, the difference in editing extent varies between the two ecotypes; for example, in floral buds, editing extent does not differ. Single-point regression analysis of the editing efficiency in a sample of recombinant inbred lines derived from a cross between Col and Ler allowed the identification of two quantitative trait loci controlling this trait. A member of the pentatricopeptide repeat protein family that carries a putative mitochondrial transit sequence has been identified near a major quantitative trait locus on chromosome 4.
Arbuscular Mycorrhizal Fungi Elicit a Novel Intracellular Apparatus inMedicago truncatulaRoot Epidermal Cells before Infection[W]
Authors: Genre Andrea , Chabaud Mireille , Timmers Ton , Bonfante Paola , Barker David G.
Published: November 2005

The penetration of arbuscular mycorrhizal (AM) fungi through the outermost root tissues of the host plant is a critical step in root colonization, ultimately leading to the establishment of this ecologically important endosymbiotic association. To evaluate the role played by the host plant during AM infection, we have studied in vivo cellular dynamics within Medicago truncatula root epidermal cells using green fluorescent protein labeling of both the plant cytoskeleton and the endoplasmic reticulum. Targeting roots with Gigaspora hyphae has revealed that, before infection, the epidermal cell assembles a transient intracellular structure with a novel cytoskeletal organization. Real-time monitoring suggests that this structure, designated the prepenetration apparatus (PPA), plays a central role in the elaboration of the apoplastic interface compartment through which the fungus grows when it penetrates the cell lumen. The importance of the PPA is underlined by the fact that M. truncatula dmi (for doesn't make infections) mutants fail to assemble this structure. Furthermore, PPA formation in the epidermis can be correlated with DMI-dependent transcriptional activation of the Medicago early nodulin gene ENOD11. These findings demonstrate how the host plant prepares and organizes AM infection of the root, and both the plant–fungal signaling mechanisms involved and the mechanistic parallels with Rhizobium infection in legume root hairs are discussed.
AREB1 Is a Transcription Activator of Novel ABRE-Dependent ABA Signaling That Enhances Drought Stress Tolerance inArabidopsis
Authors: Fujita Yasunari , Fujita Miki , Satoh Rie , Maruyama Kyonoshin , Parvez Mohammad M. , Seki Motoaki , Hiratsu Keiichiro , Ohme-Takagi Masaru , Shinozaki Kazuo , Yamaguchi-Shinozaki Kazuko
Published: November 2005

ABSCISIC ACID–RESPONSIVE ELEMENT BINDING PROTEIN1 (AREB1) (i.e., ABF2) is a basic domain/leucine zipper transcription factor that binds to the abscisic acid (ABA)–responsive element (ABRE) motif in the promoter region of ABA-inducible genes. Here, we show that expression of the intact AREB1 gene on its own is insufficient to lead to expression of downstream genes under normal growth conditions. To overcome the masked transactivation activity of AREB1, we created an activated form of AREB1 (AREB1ΔQT). AREB1ΔQT-overexpressing plants showed ABA hypersensitivity and enhanced drought tolerance, and eight genes with two or more ABRE motifs in the promoter regions in two groups were greatly upregulated: late embryogenesis abundant class genes and ABA- and drought stress–inducible regulatory genes. By contrast, an areb1 null mutant and a dominant loss-of-function mutant of AREB1 (AREB1:RD) with a repression domain exhibited ABA insensitivity. Furthermore, AREB1:RD plants displayed reduced survival under dehydration, and three of the eight greatly upregulated genes were downregulated, including genes for linker histone H1 and AAA ATPase, which govern gene expression and multiple cellular activities through protein folding, respectively. Thus, these data suggest that AREB1 regulates novel ABRE-dependent ABA signaling that enhances drought tolerance in vegetative tissues.
Conservation and Divergence of Light-Regulated Genome Expression Patterns during Seedling Development in Rice andArabidopsis [W]
Authors: Jiao Yuling , Ma Ligeng , Strickland Elizabeth , Deng Xing Wang
Published: November 2005

Genome-wide 70-mer oligonucleotide microarrays of rice (Oryza sativa) and Arabidopsis thaliana were used to profile genome expression changes during light-regulated seedling development. We estimate that the expression of ∼20% of the genome in both rice and Arabidopsis seedlings is regulated by white light. Qualitatively similar expression profiles from seedlings grown under different light qualities were observed in both species; however, a quantitatively weaker effect on genome expression was observed in rice. Most metabolic pathways exhibited qualitatively similar light regulation in both species with a few species-specific differences. Global comparison of expression profiles between rice and Arabidopsis reciprocal best-matched gene pairs revealed a higher correlation of genome expression patterns in constant light than in darkness, suggesting that the genome expression profile of photomorphogenesis is more conserved. Transcription factor gene expression under constant light exposure was poorly conserved between the two species, implying a faster-evolving rate of transcription factor gene expression in light-grown plants. Organ-specific expression profiles during seedling photomorphogenesis provide genome-level evidence for divergent light effects in different higher plant organs. Finally, overrepresentation of specific promoter motifs in root- and leaf-specific light-regulated genes in both species suggests that these cis-elements are important for gene expression responses to light.
AnArabidopsisEndo-1,4-β-d-Glucanase Involved in Cellulose Synthesis Undergoes Regulated Intracellular Cycling[W]
Authors: Robert Stéphanie , Bichet Adeline , Grandjean Olivier , Kierzkowski Daniel , Satiat-Jeunemaître Béatrice , Pelletier Sandra , Hauser Marie-Theres , Höfte Herman , Vernhettes Samantha
Published: November 2005

The synthesis of cellulose microfibrils requires the presence of a membrane-bound endo-1,4-β-d-glucanase, KORRIGAN1 (KOR1). Although the exact biochemical role of KOR1 in cellulose synthesis is unknown, we used the protein as a marker to explore the potential involvement of subcellular transport processes in cellulose synthesis. Using immunofluorescence and a green fluorescent protein (GFP)–KOR1 fusion that complemented the phenotype conferred by the kor1-1 mutant, we investigated the distribution of KOR1 in epidermal cells in the root meristem. KOR1 was localized in intracellular compartments corresponding to a heterogeneous population of organelles, which comprised the Golgi apparatus, FM4-64–labeled compartments referred to as early endosomes, and, in the case of GFP-KOR1, the tonoplast. Inhibition of cellulose synthesis by isoxaben promoted a net redistribution of GFP-KOR1 toward a homogeneous population of compartments, distinct from early endosomes, which were concentrated close to the plasma membrane facing the root surface. A redistribution of GFP-KOR1 away from early endosomes was also observed in the same cells at later stages of cell elongation. A subpopulation of GFP-KOR1–containing compartments followed trajectories along the plasma membrane, and this motility required intact microtubules. These observations demonstrate that the deposition of cellulose, like chitin synthesis in yeast, involves the regulated intracellular cycling of at least one enzyme required for its synthesis.
Localization of the Tomato Bushy Stunt Virus Replication Protein p33 Reveals a Peroxisome-to-Endoplasmic Reticulum Sorting Pathway[W]
Authors: McCartney Andrew W. , Greenwood John S. , Fabian Marc R. , White K. Andrew , Mullen Robert T.
Published: November 2005

Tomato bushy stunt virus (TBSV), a positive-strand RNA virus, causes extensive inward vesiculations of the peroxisomal boundary membrane and formation of peroxisomal multivesicular bodies (pMVBs). Although pMVBs are known to contain protein components of the viral membrane-bound RNA replication complex, the mechanisms of protein targeting to peroxisomal membranes and participation in pMVB biogenesis are not well understood. We show that the TBSV 33-kD replication protein (p33), expressed on its own, targets initially from the cytosol to peroxisomes, causing their progressive aggregation and eventually the formation of peroxisomal ghosts. These altered peroxisomes are distinct from pMVBs; they lack internal vesicles and are surrounded by novel cytosolic vesicles that contain p33 and appear to be derived from evaginations of the peroxisomal boundary membrane. Concomitant with these changes in peroxisomes, p33 and resident peroxisomal membrane proteins are relocalized to the peroxisomal endoplasmic reticulum (pER) subdomain. This sorting of p33 is disrupted by the coexpression of a dominant-negative mutant of ADP-ribosylation factor1, implicating coatomer in vesicle formation at peroxisomes. Mutational analysis of p33 revealed that its intracellular sorting is also mediated by several targeting signals, including three peroxisomal targeting elements that function cooperatively, plus a pER targeting signal resembling an Arg-based motif responsible for vesicle-mediated retrieval of escaped ER membrane proteins from the Golgi. These results provide insight into virus-induced intracellular rearrangements and reveal a peroxisome-to-pER sorting pathway, raising new mechanistic questions regarding the biogenesis of peroxisomes in plants.
PHOSPHATE TRANSPORTER TRAFFIC FACILITATOR1 Is a Plant-Specific SEC12-Related Protein That Enables the Endoplasmic Reticulum Exit of a High-Affinity Phosphate Transporter in Arabidopsis
[W]
Authors: González Esperanza , Solano Roberto , Rubio Vicente , Leyva Antonio , Paz-Ares Javier
Published: November 2005

PHOSPHATE TRANSPORTER1 (PHT1) genes encode phosphate (Pi) transporters that play a fundamental role in Pi acquisition and remobilization in plants. Mutation of the Arabidopsis thaliana PHOSPHATE TRANSPORTER TRAFFIC FACILITATOR1 (PHF1) impairs Pi transport, resulting in the constitutive expression of many Pi starvation–induced genes, increased arsenate resistance, and reduced Pi accumulation. PHF1 expression was detected in all tissues, particularly in roots, flowers, and senescing leaves, and was induced by Pi starvation, thus mimicking the expression patterns of the whole PHT1 gene family. PHF1 was localized in endoplasmic reticulum (ER), and mutation of PHF1 resulted in ER retention and reduced accumulation of the plasma membrane PHT1;1 transporter. By contrast, the PIP2A plasma membrane protein was not mislocalized, and the secretion of Pi starvation–induced RNases was not affected in the mutant. PHF1 encodes a plant-specific protein structurally related to the SEC12 proteins of the early secretory pathway. However, PHF1 lacks most of the conserved residues in SEC12 proteins essential as guanine nucleotide exchange factors. Although it functions in early secretory trafficking, PHF1 likely evolved a novel mechanism accompanying functional specialization on Pi transporters. The identification of PHF1 reveals that plants are also endowed with accessory proteins specific for selected plasma membrane proteins, allowing their exit from the ER, and that these ER exit cofactors may have a phylum-specific origin.
Public Policy, Economic Inequality, and Poverty: The United States in Comparative Perspective*
Authors: Smeeding Timothy M.
Published: November 2005

Objective. This article compares recent levels and trends in economic inequality in industrialized nations, largely those belonging to the Organization for Economic Cooperation and Development. We also examine the effects of government policies and social spending efforts on inequality.

Method. We use data from the Luxembourg Income Study and the U.S. Congressional Budget Office to measure disposable money income on an annual basis for 30 nations around the end of the 20th century. We also convert the incomes of a set of rich nations into real 2000 U.S. dollars, using a standard measure of purchasing power parity to examine absolute differences in income inequality.

Results. The United States has the highest overall level of inequality of any rich OECD nation at the beginning of the 21st century. Moreover, increases in the dispersion of total household income in the United States have been as large as, or larger than, those experienced elsewhere between 1979 and 2002. Government policies and social spending have lesser effects in the United States than in any other rich nation, and both low spending and low wages have a great impact on the final income distribution, especially among the nonelderly.

Conclusion. We speculate on the role policy plays in the final determination of income inequality. We argue that these differences cannot be explained by demography (single parents, immigrants, elders) but are more likely to be attributed to American institutions and lack of spending effort on behalf of low‐income working families.
On Inter‐ and Intra‐Individual Redistribution of the Welfare State*
Authors: Bergh Andreas
Published: November 2005

Objective. The redistributive effect of the welfare state is traditionally measured by comparing the gross and net distribution of annual income among adults. This standard approach does not account for the fact that a large share of the taxes paid by adults are paid back to the very same individuals later in life. The objective of this article is to examine the factors that determine the difference between redistribution according to the standard approach and redistribution of lifetime incomes. I also discuss under what circumstances intra‐individual redistribution is beneficial for low‐income earners.

Methods. A formal model of a simple welfare state in a society with low‐ and high‐income earners is used to describe inequality of gross and net income among adults and for complete lifetime incomes. The model is calibrated with data describing the Swedish welfare state.

Results. Theoretically, the redistribution of lifetime income can be bigger or smaller than the redistribution indicated by the standard approach. Swedish data suggest that most welfare states are more redistributive when a lifetime perspective is used compared to the standard approach.

Conclusions. Most of the redistribution carried out by modern welfare states is so‐called intra‐individual redistribution. Compared to the situation that would arise without the welfare state, intra‐individual redistribution is likely to be favorable for low‐income earners because it compensates for inequalities in the distribution of assets and access to capital markets.
The Lottery and Income Inequality in the States*
Authors: Freund Elizabeth A. , Morris Irwin L.
Published: November 2005

Objective. Since the early 1970s, income inequality in the United States has increased dramatically. We examine the impact of state lotteries on income inequality in the American states from 1976–1995.

Methods. We use cross‐sectional time‐series data to evaluate the effect of lotteries as well as those of other state tax policies, redistributive programs, and demographic factors on income inequality.

Results. We find that state lotteries foster income concentration. Ceteris paribus, states with lotteries have higher levels of income inequality than those states without a lottery. We also find that additional demographic and policy factors have an impact on income inequality in the states.

Conclusions. One of the most important policy‐oriented determinants of income inequality is the lottery and a significant portion of the increase in income inequality over our two‐decade time period is attributable to the increasing prevalence and popularity of state lotteries.
Welfare Recipients' College Attendance and Consequences for Time‐Limited Aid*
Authors: London Rebecca A.
Published: November 2005

Objective. I examine the association between total time on welfare and recipients' college attendance and graduation over a 20‐year period.

Methods. Using data from the National Longitudinal Survey of Youth, I model the determinants of college enrollment and graduation among welfare recipients, and the association between the total number of months a recipient receives aid and her college attendance and graduation. Models examine separately the effects associated with longer stays on aid while recipients attend school as well as reduced recidivism associated with college attendance and graduation.

Results. Findings indicate that attending college is associated with more months on aid, but graduating largely offsets this increase through reductions in return to aid.

Conclusions. Policymakers' concerns that including postsecondary education as a TANF activity would undermine the short‐term focus of the program are not fully supported. A greater concern is the low rate of graduation among welfare recipients, who reap the most benefits from college attendance and sacrifice the fewest months on aid.
Events that Trigger Poverty Entries and Exits*
Authors: McKernan Signe‐Mary , Ratcliffe Caroline
Published: November 2005

Objective. This article examines how events—such as changes in household composition, employment status, disability status, and economic conditions—affect poverty entries and exits. We also examine whether the role these events play in poverty transitions differs in the pre‐ and post‐welfare‐reform periods.

Methods. The analysis uses discrete‐time multivariate hazard models along with monthly, longitudinal data from the 1988, 1990, and 1996 panels of the Survey of Income and Program Participation (SIPP).

Results. Analyses show that many events are related to the likelihood of entering and exiting poverty. Of the trigger events examined, individuals living in households that experience a loss or gain of employment are the most likely to enter and exit poverty. We also find that changes in employment are more important in the 1996 to 1999 time period—after welfare reform—than in the 1988 to 1992 time period—prior to welfare reform. Finally, changes in household composition, disability status, and educational attainment are found to play a role in throwing people into poverty and helping them exit from poverty in both time periods.

Conclusions. There is no single path into or out of poverty, suggesting that multiple policies can be considered to help alleviate poverty.
Job Mobility and Early Career Wage Growth of White, African‐American, and Hispanic Women*
Authors: Alon Sigal , Tienda Marta
Published: November 2005

Objective. This article examines whether and how young women's job mobility influences racial and ethnic wage‐growth differentials during the first eight years after leaving school.

Methods. We use the NLSY‐79 Work History File to simulate the influence of job mobility on the wages of skilled and unskilled workers.

Results. African‐American and Hispanic women average less job mobility than white women, especially if they did not attend college. Unskilled women who experience frequent job changes during the first four postschool years reap positive wage returns, but turnover beyond the shopping period incurs wage penalties. Job mobility does not appear to boost wage growth for college‐educated women.

Conclusions. Among unskilled women, race and ethnic wage disparities partly derive from group differences in the frequency of job changes, but unequal returns to job mobility drive the wage gaps for skilled women. We discuss several explanations for these disparities.
Training and the Earnings of Immigrant Males: Evidence from the Canadian Workplace and Employee Survey*
Authors: Yoshida Yoko , Smith Michael R.
Published: November 2005

Objective. To improve on the existing research on earnings differentials between visible minority immigrants and the native‐born, and on the role of discrimination in producing that difference. To do this we introduce into the analysis: (1) access to training and (2) training effects on earnings growth.

Method. Using a panel data set containing information on training we test cross‐sectional models of access to training, cross‐sectional models of wage determination, and panel models of wage growth.

Results. Visible minority immigrants are disadvantaged in both access to training and earnings; education reduces the disadvantage; and they do better than the other two groups in wage growth.

Conclusions. Some results are consistent with a discrimination interpretation but, considered together, the complete sets of results are difficult to reconcile with any relatively straightforward discrimination account.
The Differential Wage Impact of the Immigration Reform and Control Act on Latino Ethnic Subgroups*
Authors: Bansak Cynthia
Published: November 2005

Objective. This article tests whether employer sanctions for hiring undocumented workers, a provision of the 1986 Immigration Reform and Control Act (IRCA), adversely affected the hourly earnings of Latino workers.

Methods. Using the Current Population Survey Outgoing Rotation Group Files from 1983–1990, a natural experiment framework is developed to assess the differential wage impact of employer sanctions on Latino ethnic subgroups.

Results. Estimates of wage changes indicate that workers of Mexican descent saw a sizeable pre‐post IRCA decline in their hourly earnings relative to Cuban or Puerto Rican workers. Moreover, this change in wages is not observed among non‐Latino white workers. Controlling for the level of enforcement explains part of this decline immediately following the passage of IRCA, and enforcement efforts continue to be a significant factor several years later.

Conclusions. The majority of evidence is consistent with the contention that employer sanctions adversely affected the earnings of Mexican workers.
Income and Power Inequality as Determinants of Environmental and Health Outcomes: Some Findings*
Authors: Torras Mariano
Published: November 2005

Objective.The article corrects for two main shortcomings in conventional economic analyses of environmental change. First is the overemphasis placed on income growth, and general disregard for other socioeconomic factors. Second is economists' often oversimplified view of the environment, where distinctions between environmental necessities such as potable water and so‐called environmental luxuries are ignored. I test for the effectiveness of power inequality in explaining access to sanitation and safe water as well as their health consequences.

Methods.I develop a two‐stage model seeking first to explain changes in the environmental variables and then population health. I employ ordinary least squares regressions on international cross‐sectional data.

Results.Some dimensions of power inequality outperform per‐capita income as possible determinants of population health. Neither power inequality nor income is clearly superior at explaining environmental quality.Conclusion. The study casts further doubt on the importance of per‐capita income in explaining environmental and health outcomes.
Poverty, Socioeconomic Change, Institutional Anomie, and Homicide*
Authors: Kim Sang‐Weon , Pridemore William Alex
Published: November 2005

Objective. This study examined institutional anomie theory in the context of transitional Russia.

Methods. We employed an index of negative socioeconomic change and measures of family, education, and polity to test the hypothesis that institutional strength conditions the effects of poverty and socioeconomic change on homicide rates.

Results. As expected, the results of models estimated using negative binomial regression show direct positive effects of poverty and socioeconomic change and direct negative effects of family strength and polity on regional homicide rates. There was no support, however, for the hypothesis that stronger social institutions reduce the effects of poverty and socioeconomic change on violence.

Conclusions. We interpret these results in the Russia‐specific setting, concluding that Russia is a rich laboratory for examining the effects of social change on crime and that empirical research in other nations is important when assessing the generalizability of theories developed to explain crime and violence in the United States.
New Fathers' Labor Supply: Does Child Health Matter?*
Authors: Noonan Kelly , Reichman Nancy E. , Corman Hope
Published: November 2005

Objective. We estimate the effect of poor child health on the labor supply of fathers post‐welfare reform, using a national sample of mostly unwed parents and their children—a group at high risk of living in poverty.

Method. We control for a rich set of covariates, include state fixed effects, and test for the endogeneity of child health by estimating bivariate probit models.

Results. We find that having a young child in poor health reduces the father's probability of being employed by four percentage points. The effect appears to be strongest among fathers who cohabit with, but are not married to, the child's mother.

Conclusion. The results suggest a potential source by which young children with serious health problems may receive lower levels of health investment than their healthier peers—their fathers' reduced likelihood of being employed.
Limousine Liberals and Corporate Conservatives: The Financial Constituencies of the Democratic and Republican Parties*
Authors: Francia Peter L. , Green John C. , Herrnson Paul S. , Powell Lynda W. , Wilcox Clyde
Published: November 2005

Objective. This study examines the backgrounds, political attitudes, issue preferences, and political participation of congressional donors who contribute $200 or more to congressional campaigns.

Methods. We use a nationwide survey of more than 1,000 donors and analyze differences among these individuals using cluster analysis.

Results. Although these significant donors are economic elites, we find they are not monolithic in their political views and attitudes. There are significant cleavages in the donor pool across and within the two major parties on various political issues and involvement in different political organizations. Perhaps most important, we find that the most active donors hold the most ideologically extreme political views. Conclusions. The results suggest that the sharp cross‐party differences and the meaningful variations within party coalitions, combined with the greater activity of more ideologically extreme donors, contribute to and reflect party polarization.
Black Substantive Representation in State Legislatures from 1971–1994*
Authors: Owens Chris T.
Published: November 2005

Objective. To determine if increased black descriptive representation in state legislatures has resulted in greater influence over policy outputs.

Methods. I examine state budgets over a 24‐year period, comparing changes in spending priorities within budgets.

Results. The results demonstrate that increased black representation has resulted in state legislatures giving greater priority to policy areas important to black elected officials.

Conclusion. When measured correctly, increased descriptive representation can result in increased substantive representation in large political institutions.
Testing a Political Economic Theory of the Media: How Were Steel Tariffs Covered?*
Authors: Kuzyk Patricia , McCluskey Jill J. , Dente Ross Susan
Published: November 2005

Objective.The objective of this article is to testStrömberg's (2001)prediction that newspapers will devote more space to costs of tariffs than to their benefits, using the recent steel tariff issue as a test case.

Method.A content analysis was performed on a sample of 123New York Times(NYT) and 177Wall Street Journal(WSJ) articles published between January 1 and September 10, 2002. The articles were coded sentence by sentence for pro‐, anti‐, and neutral‐tariff content. Comments or information deemed supportive of the tariffs, that is, touting their benefits, were coded +1, while those emphasizing the costs of tariffs were coded –1. A statement that was neutral with regard to the tariff issue was coded 0. The proportion of sentences coded –1 was then compared with the proportion coded +1.

Results.The coders found 395 sentences devoted to the negative impacts of steel tariffs versus 124 sentences devoted to their benefits out of a combined total of 3,207 sentences. The results also reveal a mild “slant” toward free trade in theWSJrelative to theNYT. In theWSJ, the proportion of lines criticizing tariffs (0.11) exceeds the proportion supporting tariffs (0.02) by a wider margin than in theNYT(0.13 vs. 0.06).

Conclusions.This article provides empirical support forStrömberg's (2001)political economy model of the media. The model implies that mass media will weaken the power of special‐interest lobbies relative to unorganized interests. Specifically, the data support Strömberg's prediction that more newspaper space would be devoted to the costs of steel tariffs—which are widely dispersed—than to their benefits—which are narrowly targeted.
Social Capital and Economic Performance in the American States*
Authors: Casey Terrence , Christ Kevin
Published: November 2005

Objective.This study tests the claim that areas with higher levels of social capital have superior economic performance.

Method.The 14‐measure index of social capital created by Robert Putnam is reconstructed for an extended time period and integrated into cross‐sectional regression models including physical capital, human capital, and other factors relevant to state economic performance.

Results.The analysis shows that social capital has no discernable influence on aggregate measures of output and employment. However, it does have a positive and significant impact on measures of economic equality and employment stability.

Conclusions.This study does not support the claim that social capital is a general prerequisite for prosperity, but it does suggest that it may serve to reinforce a particular mode of communitarian economic development.
Investor Responses to IMF Program Suspensions: Is Noncompliance Costly?*
Authors: Edwards Martin S.
Published: November 2005

Objective. This article reinvestigates the “catalytic” effects of IMF programs on investment controlling for the implementation of the program, allowing us to ascertain if capital markets respond to the mere announcement of a Fund program or its sustained positive implementation.

Methods. Using a panel of data based on the experience of 106 developing countries entering Fund programs between 1979 and 1995, I employ both probit and tobit estimations to assess the effects of the announcement of a Fund program (and performance under it) on inflows of portfolio investment.

Results. I find mixed evidence that good implementation serves to slow capital flight. I find consistently strong evidence that failed Fund programs produce portfolio flight.

Conclusion. The findings suggest that we should think about the Fund's influence (both positive and negative) in light of how capital markets respond to its signals.
Using Theory to Understand Public Support for Collective Actions that Impact the Environment: Alleviating Water Supply Problems in a Nonarid Biome*
Authors: Routhe Aaron S. , Jones Robert Emmet , Feldman David L.
Published: November 2005

Objectives. There is increasing public debate over how to meet future water supply needs in historically water‐abundant areas such as the American southeast. Citizens, policymakers, and others are struggling to find ways to meet these needs and to design political strategies for implementing them. This article examines water supply problems facing many communities in the southeast and how social theory can be used to better understand public support for collective actions designed to alleviate them. It presents a framework synthesizing recent work of Dunlap and Jones on the conceptual foundations of environmental concern research with Ajzen and Fishbein's theory of reasoned action in order to understand public support for building a dam to meet local water supply needs.

Methods. The linkages postulated by the model were empirically tested using mail‐survey data obtained from a random sample of 433 adult residents of Cumberland County, Tennessee.

Results. Results demonstrate that public support for building the dam is weak.

Conclusion. Knowledge of public beliefs, norms, and attitudes about its construction and potential impact, however, can provide policymakers, natural resource professionals, and local stakeholder groups with a solid understanding of why residents support, oppose, or are unsure about building a dam to alleviate water supply problems in this county.
Degree Completion Among Nontraditional College Students*
Authors: Taniguchi Hiromi , Kaufman Gayle
Published: November 2005

Objective. With the growing number of older students attending college, one major issue concerning these nontraditional students is their overall low completion rates. We examine factors affecting nontraditional students' degree completion.

Methods. Using data from the National Longitudinal Survey of Youth, we examine the effects of student characteristics on the probability of finishing college with event history models.

Results. Part‐time enrollment significantly deters college completion, whereas the number of prior enrollments facilitates it. Being relatively young, having high cognitive ability, and a high‐status occupational background also increase the chance of completion, but these effects partly differ by gender. On the other hand, being divorced and having young children, the factors often negatively associated with women's socioeconomic status, suppress degree completion for both genders.

Conclusions. Based on these results, we discuss how higher educational institutions and employers might be able to help increase the rate of completion among nontraditional students.
The Roles of Parenting Styles and Social Capital in the School Performance of Immigrant Asian and Hispanic Adolescents*
Authors: Pong Suet‐ling , Hao Lingxin , Gardner Erica
Published: November 2005

Objective. This study investigates the role of parenting styles and social capital (parental involvement, intergenerational closure, expectation, and trust) in accounting for school performance among ethnic groups and across immigrant generations.

Methods. Using data from the Adolescent Health Survey, we estimate fixed‐effects models to analyze students' grade‐point averages. We compare three generations of Asian students and three generations of Hispanic students to the third‐generation (native born with native parents) white students.

Results. We find significant differences by both race/ethnicity and generational status in parenting styles and forms of social capital. However, while family socioeconomic status (SES) accounts for the achievement gap between foreign‐born Hispanic and the third‐generation white students, parenting styles and forms of social capital do not moderate any ethnic‐generational differences.

Conclusions. Family influences, apart from SES, cannot explain ethnicity‐generation differences in school grades among Hispanic and Asian adolescents. This study provides conceptual clarification and empirical evidence for the significant but independent association between students' school grades and parenting styles on the one hand, and social capital on the other.
The Structure of Context: Deciphering Frame Analysis
Authors: Scheff Thomas J.
Published: November 2005

This article proposes that Goffman's Frame Analysis can be interpreted as a step toward unpacking the idea of context. His analysis implies a recursive model involving frames within frames. The key problem is that neither Goffman nor anyone else has clearly defined what is meant by a frame. I propose that it can be represented by a word, phrase, or proposition. A subjective context can be represented as an assembly of these items, joined together by operators such as and, since, if, not, and then. Furthermore, this model can be combined with the recursive levels of mutual awareness in earlier approaches to consensus. The combination would represent the intersubjective context: it can be used to find the minimum amount of background that would allow consensual interpretations of discourse. It could also construct a chain that links discourse to the institutional level, the micro-macro pathway from word and gesture to social structure. Goffman hinted that mathematical notation might be used to represent a frame assembly. By adding levels of awareness to such notation, it could represent social facts. Because the use of vernacular words rather than concepts is a problem in social science, Goffman's approach has a general as well as a particular significance.
Interpatient variability in the pharmacokinetics of the HIV non‐nucleoside reverse transcriptase inhibitor efavirenz: the effect of gender, race, and CYP2B6 polymorphism
Authors: Burger David , Van Der Heiden Ilse , La Porte Charles , Van Der Ende Marchina , Groeneveld Paul , Richter Clemens , Koopmans Peter , Kroon Frank , Sprenger Herman , Lindemans Jan , Schenk Paul , Van Schaik Ron
Published: November 2005

Aims

To characterize the demographic and pharmacogenetic factors that influence interpatient variability in the plasma concentrations of the HIV non‐nucleoside reverse transcriptase inhibitor efavirenz.

Methods

Data from all samples analyzed for efavirenz in our TDM service in 2002 and 2003 were reviewed. Information on gender, age, body weight, height, race, hormonal contraceptive use (in a subset of patients), and time between sampling and last intake was recorded. PCR‐restriction fragment length polymorphism analysis was performed to detect the cytochrome P450 2B6 (CYP2B6) C1459T variant (present in CYP2B6*6 and CYP2B6*7) which is associated with low CYP2B6 activity.

Results

A total of 255 patients were included in this analysis. The median plasma efavirenz concentration was 2.50 (interquartile range: 1.85–3.55) mg l−1. Eight patients (3.1%) were considered to have a subtherapeutic plasma concentration (<1.0 mg l−1) and 48 (18.9%) a toxic efavirenz concentration (>4.0 mg l−1). Gender, time after last intake, and race were the only factors that were significantly related to plasma efavirenz concentration in a multivariate analysis. No influence was observed for body weight, hormonal contraceptive use, and the presence of the CYP2B6 C1459T polymorphism.

Conclusions

Gender and race are important factors in determining interpatient variability in plasma efavirenz concentrations which were unaffected by the presence of the CYP2B6 C1459T polymorphism. Physicians should be particularly alert for signs of efavirenz‐induced toxicity in females and non‐Caucasian patients.
The larynx as an immunological organ: immunological architecture in the pig as a large animal model
Authors: Barker E , Haverson K , Stokes C R , Birchall M , Bailey M
Published: November 2005

The larynx is a mucosal organ positioned at the divergence of the respiratory and digestive tracts. It is exposed to a wide variety of environmental components, including foreign antigens, tobacco smoke, laryngopharyngeal reflux and pollutants. The mucosal immune system generates either active immune responses or tolerance, depending on the nature of the antigen and we hypothesize that the larynx is important organ for immunological decision-making in the airway. Because the pig is an ideal large animal model in which to explore laryngological research questions, such as those relating to laryngeal transplantation, we investigated the normal mucosal immunology of the porcine larynx. Pig larynges and tracheae were processed and prepared for bright-field microscopy and quantitative, multiple-colour immunofluorescence histology using pig-specific monoclonal antibodies. There was an abundance of immunologically active cells within the mucosa of the larynx and trachea of both the newborn and adult animal. Specifically, major histocompatibility complex class II (MHC class II+) cells, CD4+ and CD8+ cells were identified, although regional differences in numbers were apparent: specifically, the supraglottis contained fewer immunologically relevant cells than other sites sampled. There was a significant correlation between the numbers of MHC class II+ and CD4+ cells indicating co-ordinate regulation and therefore functional local interactions. The presence of such an immunological structure suggests that the larynx may have important functions in respiratory immunology and that it may trigger strong alloresponses after laryngeal transplantation.
CD28-mediated costimulation impacts on the differentiation of DC vaccination-induced T cell responses
Authors: Voigt H , Schrama D , Eggert A O , Vetter C S , Müller-Blech K , Reichardt H M , Andersen M H , Becker J C , Lühder F
Published: November 2005

Costimulatory signals such as the ones elicited by CD28/B7 receptor ligation are essential for efficient T cell activation but their role in anti-tumour immune responses remains controversial. In the present study we compared the efficacy of DC vaccination-induced melanoma specific T cell responses to control the development of subcutaneous tumours and pulmonary metastases in CD28-deficient mice. Lack of CD28-mediated costimulatory signals accelerated tumour development in both model systems and also the load of pulmonary metastases was strongly increased by the end of the observation period. To scrutinize whether lack of CD28 signalling influences priming, homing or effector function of Trp-2180−188/Kb-reactive T cells we investigated the characteristics of circulating and tumour infiltrating T cells. No difference in the frequency of Trp-2180−188/Kb-reactive CD8+ T cells could be demonstrated among the cellular infiltrate of subcutaneous tumours after DC vaccination between both genotypes. However, the number of IFN-γ-producing Trp-2-reactive cells was substantially lower in CD28-deficient mice and also their cytotoxicity was reduced. This suggests that CD28-mediated costimulatory signals are essential for differentiation of functional tumour-specific CD8+ T-effector cells despite having no impact on the homing of primed CD8+ T cells.
Multiple interleukin-18 injections promote both mouse Th1 and Th2 responses after sublethalEscherichia coliinfection
Authors: Kinoshita M , Kuranaga N , Matsumoto A , Ono S , Shinomiya N , Hiraide H , Seki S
Published: November 2005

Interleukin (IL)-18 is considered to induce exclusively the Th1 immune response but not the Th2 response in the presence of adequate IL-12 stimulation in bacterial infections. However, we demonstrate herein that multiple IL-18 injections to the mice not only enhance the early Th1 response but also stimulate the Th2 response later after viable Escherichia coli infection. Multiple IL-18 injections (three alternate-day injections) raised the serum interferon (IFN)-γ level at 6 h and serum Th2 cytokine levels, such as IL-4, IL-10 and IL-13, at 48 h after infection, while a single IL-18 injection increased only the serum IFN-γ level. Depletion of mouse CD4+ cells suppressed the IL-18-induced Th2 cytokines, IL-4, IL-10 and IL-13. In contrast, depletion of natural killer (NK)1·1+ cells reduced the IFN-γ and IL-13 levels. Moreover, multiple IL-18 injections up-regulated the serum IgM level at 72 h after infection while a single IL-18 injection did not. Interestingly, neutralization of IL-4 but not IFN-γ partially suppressed the increased serum IgM.

Liver mononuclear cells (MNCs) from the mice treated with multiple IL-18 injections significantly increased more production of not only IFN-γ but also Th2 cytokines and IgM by in vitro lipopolysaccharide (LPS) stimulation than those from the phosphate-buffered saline (PBS)-treated mice, while liver MNCs from the single IL-18-injected mice also increased IFN-γ production but significantly suppressed IL-4 and IgM production compared to those from the PBS-treated mice. Our findings suggest that multiple injections of IL-18 up-regulate both the cellular and humoral innate immunities, thereby enhancing host defence against bacterial infections.