bluuebunny/crossref_metadata_2025 huggingface dataset:
Inhibition of antithrombin by hyaluronic acid may be involved in the pathogenesis of rheumatoid arthritis
Authors: Chang Xiaotian , Yamada Ryo , Yamamoto Kazuhiko
Published: January 2005

Thrombin is a key factor in the stimulation of fibrin deposition, angiogenesis, proinflammatory processes, and proliferation of fibroblast-like cells. Abnormalities in these processes are primary features of rheumatoid arthritis (RA) in synovial tissues. Tissue destruction in joints causes the accumulation of large quantities of free hyaluronic acid (HA) in RA synovial fluid. The present study was conducted to investigate the effects of HA and several other glycosaminoglycans on antithrombin, a plasma inhibitor of thrombin. Various glycosaminoglycans, including HA, chondroitin sulfate, keratan sulfate, heparin, and heparan, were incubated with human antithrombin III in vitro. The residual activity of antithrombin was determined using a thrombin-specific chromogenic assay. HA concentrations ranging from 250 to 1000 μg/ml significantly blocked the ability of antithrombin to inhibit thrombin in the presence of Ca2+ or Fe3+, and chondroitin A, B and C also reduced this ability under the same conditions but to a lesser extent. Our study suggests that the high concentration of free HA in RA synovium may block antithrombin locally, thereby deregulating thrombin activity to drive the pathogenic process of RA under physiological conditions. The study also helps to explain why RA occurs and develops in joint tissue, because the inflamed RA synovium is uniquely rich in free HA along with extracellular matrix degeneration. Our findings are consistent with those of others regarding increased coagulation activity in RA synovium.
Alphavirus replicon particles containing the gene for HER2/neuinhibit breast cancer growth and tumorigenesis
Authors: Wang Xiaoyan , Wang Jian-Ping , Maughan Maureen F , Lachman Lawrence B
Published: January 2005

Introduction

Overexpression of the HER2/neu gene in breast cancer is associated with an increased incidence of metastatic disease and with a poor prognosis. Although passive immunotherapy with the humanized monoclonal antibody trastuzumab (Herceptin) has shown some effect, a vaccine capable of inducing T-cell and humoral immunity could be more effective.

Methods

Virus-like replicon particles (VRP) of Venezuelan equine encephalitis virus containing the gene for HER2/neu (VRP-neu) were tested by an active immunotherapeutic approach in tumor prevention models and in a metastasis prevention model.

Results

VRP-neu prevented or significantly inhibited the growth of HER2/neu-expressing murine breast cancer cells injected either into mammary tissue or intravenously. Vaccination with VRP-neu completely prevented tumor formation in and death of MMTV-c-neu transgenic mice, and resulted in high levels of neu-specific CD8+ T lymphocytes and serum IgG.

Conclusion

On the basis of these findings, clinical testing of this vaccine in patients with HER2/neu+ breast cancer is warranted.
Immunohistochemical expression of insulin-like growth factor binding protein-3 in invasive breast cancers and ductal carcinoma in situ: implications for clinicopathology and patient outcome
Authors: Vestey Sarah B , Perks Claire M , Sen Chandan , Calder Caroline J , Holly Jeff MP , Winters Zoe E
Published: January 2005

Introduction

Insulin-like growth factor binding protein-3 (IGFBP-3) differentially modulates breast epithelial cell growth through insulin-like growth factor (IGF)-dependent and IGF-independent pathways and is a direct (IGF-independent) growth inhibitor as well as a mitogen that potentiates EGF (epidermal growth factor) and interacts with HER-2. Previously, high IGFBP-3 levels in breast cancers have been determined by enzyme-linked immunosorbent assay and immunoradiometric assay methods. In vitro, IGFBP-3's mechanisms of action may involve cell membrane binding and nuclear translocation. To evaluate tumour-specific IGFBP-3 expression and its subcellular localisation, this study examined immunohistochemical IGFBP-3 expression in a series of invasive ductal breast cancers (IDCs) with synchronous ductal carcinomas in situ (DCIS) in relation to clinicopathological variables and patient outcome.

Methods

Immunohistochemical expression of IGFBP-3 was evaluated with the sheep polyclonal antiserum (developed in house) with staining performed as described previously.

Results

IGFBP-3 was evaluable in 101 patients with a variable pattern of cytoplasmic expression (positivity of 1+/2+ score) in 85% of invasive and 90% of DCIS components. Strong (2+) IGFBP-3 expression was evident in 32 IDCs and 40 cases of DCIS. A minority of invasive tumours (15%) and DCIS (10%) lacked IGFBP-3 expression. Nuclear IGFBP-3 expression was not detectable in either invasive cancers or DCIS, with a consistent similarity in IGFBP-3 immunoreactivity in IDCs and DCIS. Positive IGFBP-3 expression showed a possible trend in association with increased proliferation (P = 0.096), oestrogen receptor (ER) negativity (P = 0.06) and HER-2 overexpression (P = 0.065) in invasive tumours and a strong association with ER negativity (P = 0.037) in DCIS. Although IGFBP-3 expression was not an independent prognosticator, IGFBP-3-positive breast cancers may have shorter disease-free and overall survivals, although these did not reach statistical significance.

Conclusions

Increased breast epithelial IGFBP-3 expression is a feature of tumorigenesis with cytoplasmic immunoreactivity in the absence of significant nuclear localisation in IDCs and DCIS. There are trends between high levels of IGFBP-3 and poor prognostic features, suggesting that IGFBP-3 is a potential mitogen. IGFBP-3 is not an independent prognosticator for overall survival or disease-free survival, to reflect its dual effects on breast cancer growth regulated by complex pathways in vivo that may relate to its interactions with other growth factors.
Letrozole sensitizes breast cancer cells to ionizing radiation
Authors: Azria David , Larbouret Christel , Cunat Severine , Ozsahin Mahmut , Gourgou Sophie , Martineau Pierre , Evans Dean B , Romieu Gilles , Pujol Pascal , Pèlegrin Andre
Published: January 2005

Introduction

Radiotherapy (RT) is considered a standard treatment option after surgery for breast cancer. Letrozole, an aromatase inhibitor, is being evaluated in the adjuvant setting. We determined the effects of the combination of RT and letrozole in the aromatase-expressing breast tumour cell line MCF-7CA, stably transfected with the CYP19 gene.

Methods

Irradiations were performed using a cobalt-60 source with doses ranging from 0 to 4 Gy. Cells were incubated with androstenedione in the presence or absence of letrozole. Effects of treatment were evaluated using clonogenic assays, tetrazolium salt colorimetric (MTT) assays, and cell number determinations. Cell-cycle analyses were conducted using flow cytometry.

Results

The survival fraction at 2 Gy was 0.66 for RT alone and was 0.44 for RT plus letrozole (P = 0.02). Growth of MCF-7CA cells as measured by the cell number 6 days after radiotherapy (2 and 4 Gy) was decreased by 76% in those cells treated additionally with letrozole (0.7 μM) compared with those receiving radiotherapy alone (P = 0.009). Growth inhibition, assessed either by cell number (P = 0.009) or by the MTT assay (P = 0.02), was increased after 12 days of the combination treatment. Compared with radiation alone, the combination of radiation and letrozole produced a significant decrease in radiation-induced G2 phase arrest and a decrease of cells in the S phase, with cell redistribution in the G1 phase.

Conclusions

These radiobiological results may form the basis for concurrent use of letrozole and radiation as postsurgical adjuvant therapy for breast cancer.
Haplotype analysis of common variants in the BRCA1 gene and risk of sporadic breast cancer
Authors: Cox David G , Kraft Peter , Hankinson Susan E , Hunter David J
Published: January 2005

Introduction

Truncation mutations in the BRCA1 gene cause a substantial increase in risk of breast cancer. However, these mutations are rare in the general population and account for little of the overall incidence of sporadic breast cancer.

Method

We used whole-gene resequencing data to select haplotype tagging single nucleotide polymorphisms, and examined the association between common haplotypes of BRCA1 and breast cancer in a nested case-control study in the Nurses' Health Study (1323 cases and 1910 controls).

Results

One haplotype was associated with a slight increase in risk (odds ratio 1.18, 95% confidence interval 1.02–1.37). A significant interaction (P = 0.05) was seen between this haplotype, positive family history of breast cancer, and breast cancer risk. Although not statistically significant, similar interactions were observed with age at diagnosis and with menopausal status at diagnosis; risk tended to be higher among younger, pre-menopausal women.

Conclusions

We have described a haplotype in the BRCA1 gene that was associated with an approximately 20% increase in risk of sporadic breast cancer in the general population. However, the functional variant(s) responsible for the association are unclear.
Differentiating midazolam over-sedation from neurological damage in the intensive care unit
Authors: McKenzie Catherine A , McKinnon William , Naughton Declan P , Treacher David , Davies Graham , Phillips Gary J , Hilton Philip J
Published: January 2005

Introduction

Midazolam is used routinely to sedate patients in the intensive care unit (ICU). We suspected that midazolam over-sedation was occurring in the ICU of the Guy's and St. Thomas' Trust and that it could be difficult to differentiate this from underlying neurological damage. A sensitive assay for detecting midazolam and 1-hydroxymidazolam glucuronide (1-OHMG) in serum was developed and applied in the clinical setting.

Methods

In the present study we evaluated a series of cases managed in a mixed medical, surgical and trauma ICU. Serum was collected from 26 patients who received midazolam, were 'slow to wake' and in whom there was suspicion of neurological damage. Patient outcome was followed in terms of mortality, neurological recovery and neurological damage on discharge.

Results

Out of 26 patients, 13 had detectable serum levels of midazolam and/or 1-OHMG after a median of 67 hours (range 36–146 hours) from midazolam cessation. Of these 13 patients in whom midazolam/1-OHMG was detectable, 10 made a full neurological recovery. Of the remaining 13 patients with no detectable midazolam/1-OHMG, three made a full neurological recovery; 10 patients were subsequently found to have suffered neurological damage (P < 0.002), eight of whom died and two were discharged from the ICU with profound neurological damage.

Conclusion

These findings confirm that prolonged sedation after midazolam therapy should be considered in the differential diagnosis of neurological damage in the ICU. This can be reliably detected by the assay method described. The effects of midazolam/1-OHMG persist days after administration of midazolam has ceased. After prolonged sedation has been excluded in this patient group, it is highly likely that neurological damage has occurred.
Increased blood flow prevents intramucosal acidosis in sheep endotoxemia: a controlled study
Authors: Dubin Arnaldo , Murias Gastón , Maskin Bernardo , Pozo Mario O , Sottile Juan P , Barán Marcelo , Edul Vanina S Kanoore , Canales Héctor S , Badie Julio C , Etcheverry Graciela , Estenssoro Elisa
Published: January 2005

Introduction

Increased intramucosal–arterial carbon dioxide tension (PCO2) difference (ΔPCO2) is common in experimental endotoxemia. However, its meaning remains controversial because it has been ascribed to hypoperfusion of intestinal villi or to cytopathic hypoxia. Our hypothesis was that increased blood flow could prevent the increase in ΔPCO2.

Methods

In 19 anesthetized and mechanically ventilated sheep, we measured cardiac output, superior mesenteric blood flow, lactate, gases, hemoglobin and oxygen saturations in arterial, mixed venous and mesenteric venous blood, and ileal intramucosal PCO2 by saline tonometry. Intestinal oxygen transport and consumption were calculated. After basal measurements, sheep were assigned to the following groups, for 120 min: (1) sham (n = 6), (2) normal blood flow (n = 7) and (3) increased blood flow (n = 6). Escherichia coli lipopolysaccharide (5 μg/kg) was injected in the last two groups. Saline solution was used to maintain blood flood at basal levels in the sham and normal blood flow groups, or to increase it to about 50% of basal in the increased blood flow group.

Results

In the normal blood flow group, systemic and intestinal oxygen transport and consumption were preserved, but ΔPCO2 increased (basal versus 120 min endotoxemia, 7 ± 4 versus 19 ± 4 mmHg; P < 0.001) and metabolic acidosis with a high anion gap ensued (arterial pH 7.39 versus 7.35; anion gap 15 ± 3 versus 18 ± 2 mmol/l; P < 0.001 for both). Increased blood flow prevented the elevation in ΔPCO2 (5 ± 7 versus 9 ± 6 mmHg; P = not significant). However, anion-gap metabolic acidosis was deeper (7.42 versus 7.25; 16 ± 3 versus 22 ± 3 mmol/l; P < 0.001 for both).

Conclusions

In this model of endotoxemia, intramucosal acidosis was corrected by increased blood flow and so might follow tissue hypoperfusion. In contrast, anion-gap metabolic acidosis was left uncorrected and even worsened with aggressive volume expansion. These results point to different mechanisms generating both alterations.
GOToolBox: functional analysis of gene datasets based on Gene Ontology
Authors: Martin David , Brun Christine , Remy Elisabeth , Mouren Pierre , Thieffry Denis , Jacq Bernard
Published: January 2005

We have developed methods and tools based on the Gene Ontology (GO) resource allowing the identification of statistically over- or under-represented terms in a gene dataset; the clustering of functionally related genes within a set; and the retrieval of genes sharing annotations with a query gene. GO annotations can also be constrained to a slim hierarchy or a given level of the ontology. The source codes are available upon request, and distributed under the GPL license.
Integrating phenotypic and expression profiles to map arsenic-response networks
Authors: Haugen Astrid C , Kelley Ryan , Collins Jennifer B , Tucker Charles J , Deng Changchun , Afshari Cynthia A , Brown J Martin , Ideker Trey , Van Houten Bennett
Published: January 2005

Background

Arsenic is a nonmutagenic carcinogen affecting millions of people. The cellular impact of this metalloid in Saccharomyces cerevisiae was determined by profiling global gene expression and sensitivity phenotypes. These data were then mapped to a metabolic network composed of all known biochemical reactions in yeast, as well as the yeast network of 20,985 protein-protein/protein-DNA interactions.

Results

While the expression data unveiled no significant nodes in the metabolic network, the regulatory network revealed several important nodes as centers of arsenic-induced activity. The highest-scoring proteins included Fhl1, Msn2, Msn4, Yap1, Cad1 (Yap2), Pre1, Hsf1 and Met31. Contrary to the gene-expression analyses, the phenotypic-profiling data mapped to the metabolic network. The two significant metabolic networks unveiled were shikimate, and serine, threonine and glutamate biosynthesis. We also carried out transcriptional profiling of specific deletion strains, confirming that the transcription factors Yap1, Arr1 (Yap8), and Rpn4 strongly mediate the cell's adaptation to arsenic-induced stress but that Cad1 has negligible impact.

Conclusions

By integrating phenotypic and transcriptional profiling and mapping the data onto the metabolic and regulatory networks, we have shown that arsenic is likely to channel sulfur into glutathione for detoxification, leads to indirect oxidative stress by depleting glutathione pools, and alters protein turnover via arsenation of sulfhydryl groups on proteins. Furthermore, we show that phenotypically sensitive pathways are upstream of differentially expressed ones, indicating that transcriptional and phenotypic profiling implicate distinct, but related, pathways.
Hidden localization motifs: naturally occurring peroxisomal targeting signals in non-peroxisomal proteins
Authors: Neuberger Georg , Kunze Markus , Eisenhaber Frank , Berger Johannes , Hartig Andreas , Brocard Cecile
Published: January 2005

Background

Can sequence segments coding for subcellular targeting or for posttranslational modifications occur in proteins that are not substrates in either of these processes? Although considerable effort has been invested in achieving low false-positive prediction rates, even accurate sequence-analysis tools for the recognition of these motifs generate a small but noticeable number of protein hits that lack the appropriate biological context but cannot be rationalized as false positives.

Results

We show that the carboxyl termini of a set of definitely non-peroxisomal proteins with predicted peroxisomal targeting signals interact with the peroxisomal matrix protein receptor peroxin 5 (PEX5) in a yeast two-hybrid test. Moreover, we show that examples of these proteins - chicken lysozyme, human tyrosinase and the yeast mitochondrial ribosomal protein L2 (encoded by MRP7) - are imported into peroxisomes in vivo if their original sorting signals are disguised. We also show that even prokaryotic proteins can contain peroxisomal targeting sequences.

Conclusions

Thus, functional localization signals can evolve in unrelated protein sequences as a result of neutral mutations, and subcellular targeting is hierarchically organized, with signal accessibility playing a decisive role. The occurrence of silent functional motifs in unrelated proteins is important for the development of sequence-based function prediction tools and the interpretation of their results. Silent functional signals have the potential to acquire importance in future evolutionary scenarios and in pathological conditions.
The effect of book genre in the repeated readings of mothers and their children with language impairment: a pilot investigation
Authors: Kaderavek Joan N , Justice Laura M
Published: January 2005

This pilot investigation compared the language use of mothers and their four children with language impairment during in-home readings of two storybook genres. Mother-child dyads repeatedly read two book genres, narrative-only and narrative + manipulative storybooks. The language output during the repeated readings was transcribed and analysed for utterance and discourse features. Mother language output did not vary across book genre, whereas the children demonstrated greater mean length of utterance and increased percentage of question use during the narrative + manipulative book interactions relative to narrative-only interactions. Implications of these findings are discussed.
Beyond Bipolar Conceptualizations and Measures: The Case of Attitudes and Evaluative Space
Authors: Cacioppo John T. , Gardner Wendi L. , Berntson Gary G.
Published: January 2005

All organisms must be capable of differentiating hostile from hospitable stimuli to survive. Typically, this evaluative discrimination is conceptualized as being bipolar (hostile-hospitable). This conceptualization is certainly evident in the area of attitudes, where the ubiquitous bipolar attitude measure, by gauging the net affective predisposition toward a stimulus, treats positive and negative evaluative processes as equivalent, reciprocally activated, and interchangeable. Contrary to conceptualizations of this evaluative process as bipolar, recent evidence suggests that distinguishable motivational systems underlie assessments of the positive and negative significance of a stimulus. Thus, a stimulus may vary in terms of the strength of positive evaluative activation and the strength of negative evaluative activation it evokes. Low activation of positive and negative evaluative processes by a stimulus reflects attitude neutrality or indifference, whereas high activation of positive and negative evaluative processes reflects attitude ambivalence. As such, attitudes can be represented more completely within a bivariate space than along a bipolar continuum. Evidence is reviewed showing that the positive and negative evaluative processes underlying many attitudes are distinguishable (stochastically and functionally independent), are characterized by distinct activation functions (positivity offset and negativity bias principles), are related differentially to attitude ambivalence (corollary of ambivalence asymmetries), have distinguishable antecedents (heteroscedacity principle), and tend to gravitate from a bivariate toward a bipolar structure when the underlying beliefs are the target of deliberation or a guide for behavior (principle of motivational certainty). The implications for societal phenomena such as political elections and democratic structures are discussed.
The Symbolic Self in Evolutionary Context
Authors: Sedikides Constantine , Skowronski John J.
Published: January 2005

We propose that the capacity for a symbolic self (a flexible and multifaceted cognitive representation of an organism's own attributes) in humans is a product of evolution. In pursuing this argument, we note that some primates possess rudimentary elements of a self (an objectified self) and that the symbolic self (a) is a trait that is widely shared among humans, (b) serves adaptive functions, and (c) could have evolved in response to environmental pressures, with ecological and social pressures being of particular relevance. We suggest that these two environmental pressures caused the symbolic self to emerge in the Pleistocene epoch as an adaptation for Homo erectus, and we review the possible functions served by such an adaptation.
Levels of Analysis and the Explanation of the Costs and Benefits of Cooperation
Authors: Messick David M. , Liebrand Wim B. G.
Published: January 2005

In this article we contrast static and dynamic theories of the effects of increasing the costs and benefits of cooperation in a repeated play prisoners' dilemma (PD). Using computer simulation as the methodology, we show that different decision heuristics respond differently to changes in the cost-benefit structure of a PD game, an effect not expected by static theories of cooperation. In addition, one of the heuristics, “win-stay, lose-change,” displays the pattern of cooperation predicted by static theories, but the underlying mechanisms are qualitatively differentfrom those assumed in the static theory. This demonstration raises questions about the external validity of the different types of social psychological theory.
Performance Effects of Motivational State: A Meta-Analysis
Authors: Utman Christopher H.
Published: January 2005

Researchers (e.g., Butler, 1987; Elliott & Dweck, 1988; Grolnick & Ryan, 1987) have recently studied the impact of two different motivational states and have hypothesized that attempting to attain mastery (learning goal) leads to better performance than attempting to demonstrate that one has high ability (performance goal). This article presents a meta-analysis of research in which motivational states are manipulated and confirms that learning goals lead to better performance than do performance goals. The results also indicate that the learning goal advantage may be limited to relatively complex tasks and that the learning goal advantage is smaller for young children than for older individuals. Further, the learning goal advantage was larger when learning goals were moderately pressuring and when participants were tested alone. Theoretical integration of various theories of motivation and practical implications of the findings are discussed.
Conceptual and Methodological Issues in Testing the Circumplex Structure of Data in Personality and Social Psychology
Authors: Fabrigar Leandre R. , Visser Penny S. , Browne Michael W.
Published: January 2005

Circumplex representations of data have enjoyed widespread popularity in personality and social psychological research. In this article we review the conceptual assumptions implied by circumplex representations and we discuss the limitations of traditional statistical methods for testing these assumptions. A relatively nontechnical overview of a new covariance structure modeling approach to testing circumplex structure is provided. The use of this approach is illustrated with two published data sets. The advantages and disadvantages of this approach relative to more traditional statistical approaches are discussed. The conclusion is that the covariance structure modeling approach has significant advantages in that it provides a closer conceptual match to the theoretical assumptions of circumplex representations, supplies information more directly relevant to circumplex representations and permits more precise and flexible testing of hypotheses derived from circumplex representations.
The Evolution of Truly Social Cognition: The Core Configurations Model
Authors: Caporael Linnda R.
Published: January 2005

This article introduces a vocabulary suitable for evolutionary analyses in the human cognitive, social, and behavioral sciences. The vocabulary carves a middle way between advocates and critics of evolutionary perspectives by substituting the concept of repeated assembly for nature-nurture dualism. A model of core configurations-based on human morphology and ecology in human evolutionary history-is presented, and I argue that these configurations offace-to-face groups are the selective context for uniquely human mental systems. Hence, human cognition is “truly social,” specialized for group living. The relevance of the core configuration model is illustrated with respect to two areas of interest to social psychologists: the self and social identity, and distributed cognition and shared reality. A final section illustrates the integrative power of the core configuration model with a brief comparison of the social and cognitive tasks faced by scientists and foragers.
The Accuracy-Confidence Correlation in the Detection of Deception
Authors: DePaulo Bella M. , Charlton Kelly , Cooper Harris , Lindsay James J. , Muhlenbruck Laura
Published: January 2005

A meta-analysis was conducted of research on the relation between judges' accuracy at detecting deception and their confidence in their judgments. A total of 18 independent samples revealed an average weighted accuracy-confidence correlation of .04, a relation not significantly different from zero. However, confidence was positively correlated with judges' tendency to perceive messages as truthful, regardless of the actual truthfulness of the messages. Judges were also more confident when they really were rating truths compared to when they were rating lies. Also, men were more confident than women, and judges who had a closer relationship to the message sender felt more confident in their judgments of truths and lies. Methodological and theoretical explanations for these findings are discussed.
Why Aren't Indices of Relationship Costs Always Negatively Related to Indices of Relationship Quality?
Authors: Clark Margaret S. , Grote Nancy K.
Published: January 2005

Many researchers have made the seemingly straightforward predictions that relationship rewards will be positively, and relationship costs will be negatively, associated with indices of relationship quality. Existing literature supports the hypothesis for rewards, but evidence regarding costs is mixed. Depending on the study, indices of costs have been observed to be negatively associated, unassociated, and even positively associated with relationship quality. We argue that the mixed results may have been due in part to past cost measures tapping three separate constructs: (a) a partner's intentional poor behavior directed at the participant, (b) negative things associated with the relationship (but not caused by the partner's intentional behavior), and (c) behaving in such a manner as to meet a partner's needs—something which often may involve performing undesirable activities, foregoing desired opportunities, or giving up money, time, or goods. We believe the first two types of costs should be negatively associated with relationship quality. However, we argue that the last type, because it involves adhering to communal norms (Clark & Mills, 1979, 1993) will often tend to be either negligibly or even positively associated with relationship quality. In two studies the occurrence of these three categories of events in close relationships as well as the quality of those relationships were measured. The overall pattern of results supports our specific hypotheses as well as the general idea that a lack of conceptual clarity regarding “costs” has contributed to the current mixed nature of our literature on links between relationship costs and relationship quality.
Social Identity Theory's Self-Esteem Hypothesis: A Review and Some Suggestions for Clarification
Authors: Rubin Mark , Hewstone Miles
Published: January 2005

Distinctions are made between global and specific, personal and social, and trait and state self-esteem, and these are used to structure a review of over 40 studies concerning social identity theory's hypothesis that (a) intergroup discrimination elevates self-esteem and (b) low self-esteem motivates discrimination. It is observed that researchers have tended to employ measures of global personal trait self-esteem in their investigations of this self-esteem hypothesis, and it is argued that measures of specific social state self-esteem are more consistent with social identity theory's assumptions. Although no convincing evidence is found for the self-esteem hypothesis in its full and unqualified form, it is argued that this is due to a lack of specificity in its formulation and it is suggested that a more qualified and specific version of the hypothesis may be more appropriate.
Suppression as a Stereotype Control Strategy
Authors: Monteith Margo J. , Sherman Jeffrey W. , Devine Patricia G.
Published: January 2005

Recent research reveals that efforts to suppress stereotypic thoughts can backfire and produce a rebound effect, such that stereotypic thinking increases to a level that is even greater than if no attempt at stereotype control was initially exercised (e.g., Macrae, Bodenhausen, Milne, & Jetten, 1994). The primary goal of this article is to present an in-depth theoretical analysis of stereotype suppression that identifies numerous potential moderators of the effect of stereotype suppression on the likelihood of subsequent rebound. Our analysis of stereotype suppression focuses on two broad issues: the influence of level of prejudice and the influence of processing goals on the activation versus application of stereotypes. Although stereotype rebound occurs under some circumstances, we suggest that a complete understanding of this phenomenon requires consideration of the full array of possible moderating influences.
Metacognition in Action: The Importance of Implementation Intentions
Authors: Gollwitzer Peter M. , Schaal Bernd
Published: January 2005

When people furnish their goal intentions (“I intend to attain the goal x!”) with implementation intentions (“I will initiate the goal-directed response y when situation z arises!”), the initiation of goal-directed responses becomes automatized. As this type of automaticity stems from a single act of will, it is referred to as strategic automaticity. We report various studies demonstrating that strategic automaticity leads to immediate and efficient responding, which does not need a conscious intent. In addition, the situational cues specified in implementation intentions seem to be easily detected and readily attended to. Further research indicates that the strategic automaticity induced by implementation intentions also helps resist temptations and fight bad habits. Following Nelson's (1996; Nelson & Narens, 1994) model of metacognition, we suggest that goal intentions and, in particular, implementation intentions are important components of the metacognitive control of action geared toward its initiation, continuation, and termination.
Affect in Electoral Politics
Authors: Glaser Jack , Salovey Peter
Published: January 2005

Recent U.S. history provides vivid illustrations of the importance of politicians' emotional displays in subsequent judgments of them. Yet, a review of empirical research on the role of affect (emotion, mood, and evaluation) in electoral politics reveals little work that has focused on the impact of candidates' emotional expression on voters' preferences for them. A theoretical framework is proposed to identify psychological mechanisms by which a target's displays of emotion influence judgments of that target. Findings from the emerging literature on emotions and politics challenge the traditional assumption of political science that voters make decisions based solely on the cold consideration of nonaffectively charged information. The affect and politics literature, although somewhat unfocused and broad, represents an interdisciplinary domain of study that contributes to the understanding of both electoral politics and social interaction more generally.
A Theory of Unmitigated Communion
Authors: Helgeson Vicki S. , Fritz Heidi L.
Published: January 2005

Research has established that women suffer more often than men from depression. Sex role socialization has been offered as one explanation for this sex difference, but traditional measures of female gender-related traits are not related to depressive symptoms. We argue that thus far research has failed to distinguish the traditional measure of female gender-related traits, communion, from another set of gender-related traits, unmitigated communion. Unmitigated communion is a focus on and involvement with others to the exclusion of the self. Unmitigated communion, but not communion, is related to psychological distress, including depressive symptoms, and accounts for sex differences in distress. We examine the relation of unmitigated communion to communion as well as other personality constructs and then describe the cognitive and behavioral features of unmitigated communion. We note the implications of unmitigated communion for physical and psychological well-being and speculate on possible origins.
Paranoid Cognition in Social Systems: Thinking and Acting in the Shadow of Doubt
Authors: Kramer Roderick M.
Published: January 2005

Distrust and suspicion are common and recurring problems at all levels of social organization, ranging from the interpersonal to the collective. Unfortunately, our understanding of the origins and dynamics of such distrust and suspicion remains far from complete. A primary aim of this research, accordingly, was to articulate a new framework for conceptualizing a form of exaggerated distrust and suspicion termed paranoid social cognition. Drawing on recent psychological theory and research, this framework identifies the social cognitive underpinnings of paranoid cognitions. It also specifies some of the situational determinants of such cognition and elaborates on the psychological, behavioral, and social dynamics that sustain them.
Selective Play: Choosing Partners in an Uncertain World
Authors: Hayashi Nahoko , Yamagishi Toshio
Published: January 2005

The theoretical implications of introducing the “selective play” paradigm to experimental gaming research are discussed. In the traditional “forced play” environment, players are locked in a particular relationship and do not have options of leaving the current relationship and joining another. In the selective play environment players are given the options of leaving the current relationship andforming a new relationship. A previous computer tournament of prisoner's dilemma network (Hayashi, 1993) showed that out-for-tat (OFT) strategy performed very well in the selective play environment. OFT keeps cooperating with a partner until the partner defects; it deserts the partner and turns to someone else as soon as the partner defects. Results of a new computer tournament that introduced opportunity costs, however, point to the limits of the OFT's strength. OFT prematurely forms a commitment relationship with a cooperative partner and fails to utilize better opportunities. The best performer in the second tournament was the only one who was “trustful” and had a positive bias in calculating the expected payoff of interactions with a “stranger.”
The Intensity of Emotion
Authors: Brehm Jack W.
Published: January 2005

A theory is outlined that assumes that emotions are motivational states with the special function of producing adaptation to situational conditions. The theory assumes that the emotional system lies in the central nervous system, that it is fast to react, able to change quickly from one emotional state to another, produces only one emotion at a time, and that the intensity of that emotion is a nonmonotonic function of deterrence to the aim of the emotion. Supporting data from several experimental tests are reported, and selected theoretical problems are discussed.
Passion, Intimacy, and Time: Passionate Love as a Function of Change in Intimacy
Authors: Baumeister Roy F. , Bratslavsky Ellen
Published: January 2005

To build on existing theories about love, we propose that passion is a function of change in intimacy (i.e., the first derivative of intimacy overtime). Hence, passion will be low when intimacy is stable (either high or low), but rising intimacy will create a strong sense of passion. This view is able to account for a broad range of evidence, including frequency of sex in long-term relationships, intimate and sexual behavior of extraverts, gender differences in intimate behavior, gain and loss effects of communicated attraction, the biologically atypical human preference for face-to-face coitus, and patterns of distress in romantic breakups. Although this view may provide a good fit to available evidence, the totality of evidence is not yet adequate for a definitive conclusion, and suggestions for further research are offered.
Reflectivity and rain rate in and below drizzling stratocumulus
Authors: Comstock Kimberly K. , Wood Robert , Yuter Sandra E. , Bretherton Christopher S.
Published: January 2005

Ship‐based radar measurements obtained during the East Pacific Investigation of Climate 2001 stratocumulus (Sc) cruise are used to derive characteristics of the rainfall from drizzling Sc. Reflectivity to rain rate (Z–R) relationships are determined from shipboard raindrop‐size distribution measurements obtained from observations using filter‐paper, and compared to Z–R relationships derived from aircraft probe data from below north‐east Atlantic drizzling Sc and stratus. A model for the evaporation and sedimentation of drizzle is combined with reflectivity profiles from a millimetre‐wavelength cloud radar to derive information on the mean raindrop radius and drizzle drop concentrations at cloud base, and to show how Z–R relationships change with height below the cloud base. The Z–R relationships are used in conjunction with shipborne C‐band radar reflectivity data to estimate areal average precipitation with uncertainties at cloud base and at the surface. In the Sc drizzle Z–R relationship, Z = aRb (where a and b are constants), the estimated exponent b = 1.1 to 1.4 is lower than commonly observed in deep convective rain (b = 1.5). Analyses indicate that variations in Sc rain rates and reflectivities are influenced both by fluctuations in drizzle drop concentration and in mean radius, but that number concentration contributes more to the modulation of rain rate in Sc. Rain rates derived using the scanning C‐band radar are found to be spatially variable, with much of the accumulation originating from a small fraction of the drizzling area. The observations also suggest that rain rate in marine Sc is strongly dependent on cloud liquid‐water path, and inversely correlated with cloud droplet concentration. Copyright © 2004 Royal Meteorological Society
Soil moisture–precipitation feedback on the North American monsoon system in the MM5‐OSU model
Authors: Xu Jianjun , James Shuttleworth W. , Gao X. , Sorooshian Soroosh , Small Eric E.
Published: January 2005

In this study, the Pennsylvania State University/National Center for Atmospheric Research fifth generation Mesoscale Model (MM5) linked to the Oregon State University (OSU) land‐surface scheme, is used to assess the strength of soil moisture–precipitation feedback in the region of influence of the North American monsoon (NAM). Two control simulations are made with external forcing taken from the National Centers for Environmental Prediction re‐analysis, and with a nested horizontal resolution of 30 km, for the period 1 June to 30 September in wetter than average (1999) and drier than average (2000) monsoon seasons. These two model runs are then repeated with a prescribed precipitation rate anomaly in July over the entire NAM region, and comparisons made between atmospheric and land‐surface states in the two control runs and the two runs with anomalous precipitation. The results show that size and importance of soil moisture–precipitation feedbacks in the NAM region have substantial interannual variability, and that the resulting behaviour has a strong dependency on the intensity of the prescribed precipitation anomaly. It is also shown that a marked precipitation anomaly in the NAM region results in modified soil moisture, rainfall, and surface temperature, which persist for about one month, and that a precipitation anomaly within the NAM region not only has an impact on soil moisture locally, but also causes a remote, downwind soil moisture anomaly one month later. Analysis of the modelled response to the soil moisture anomaly indicates that not only land–atmosphere interactions, but also the large‐scale atmospheric circulation act together to determine the modified precipitation and soil moisture fields in the NAM system. Copyright © 2004 Royal Meteorological Society
Investigating atmospheric predictability on Mars using breeding vectors in a general‐circulation model
Authors: Newman C. E. , Read P. L. , Lewis S. R.
Published: January 2005

A breeding vectors approach is used to investigate the hypothesis that the Martian atmosphere is predictable at certain times of year, by identifying the fastest‐growing modes of instability at different times in a Mars general‐circulation model. Results indicate that the period from northern mid‐spring until mid‐autumn is remarkably predictable, with negative global growth rates for a range of conditions, in contrast to the situation on the earth.

From northern late autumn to early spring growing modes do occur, peaking in northern high latitudes and near winter solstice. Reducing the size of the initial perturbations increases global growth rates in most cases, supporting the idea that instabilities which saturate nonlinearly at lower amplitudes have generally faster growth rates. In late autumn/early winter the fastest‐growing modes (‘bred vectors’) are around the north pole, increase with dust loading, and probably grow via barotropic as well as baroclinic energy conversion. In northern late winter/early spring the bred vectors are around the north pole and are strongly baroclinic in nature. As dust loading (and with it the global circulation strength) is increased their growth rates first decrease, as the baroclinic mode is suppressed, then increase again as the fastest‐growing instabilities switch to being those which dominated earlier in the year. If dust levels are very low during late northern autumn (late southern spring) then baroclinic modes are also found around the spring pole in the south, though for a slight increase in dust loading the dominant modes shift back to northern high latitudes.

The bred vectors are also used as perturbations to the initial conditions for ensemble simulations. One possible application within the Mars model is as a means of identifying regions and times when dust‐lifting activity (related to surface wind stress) might show significant interannual variability for a given model configuration, without the need to perform long, computationally expensive multi‐year model runs with each new set‐up. This is tested for a time of year when previous multi‐year experiments showed significant variability in dust storm onset in the region north of Chryse. Despite the model having no feedbacks between dust lifting and atmospheric state (unlike the original multi‐year run), the ensemble members still show maximum divergence in this region in terms of near‐surface wind stress, suggesting both that this application deserves further testing, and that the intrinsic atmospheric variability alone may be important in producing interannual variability in this storm type. Copyright © 2004 Royal Meteorological Society
Kelvin–Helmholtz billow evolution from a localized source
Authors: Smyth W. D.
Published: January 2005

The envelope function for Kelvin–Helmholtz billows growing from a point disturbance is derived on the basis of linear perturbation theory. The result describes an elliptical patch of billows that expands linearly in time as the billows grow. An analytical model of the dispersion relation is used to derive quantitative expressions for the spreading rate and ellipticity of the patch as functions of the bulk Richardson number. The theoretical results are verified using a combination of two‐ and three‐dimensional nonlinear simulations, and are compared with visual observations of billow patches in the atmosphere. Copyright © 2004 Royal Meteorological Society
Effects of horizontal gradients on GPS radio occultation observation operators. I: Ray tracing
Authors: Poli P. , Joiner J.
Published: January 2005

Global Positioning System (GPS) radio occultation (RO) bending angle and refractivity data provide information about the vertical structure of temperature and humidity in the earth's atmosphere. Assuming spherical symmetry in a GPS RO observation operator creates errors when calculating GPS RO observables from a background. These errors find their source in the presence of horizontal gradients of temperature and humidity. Tangent point drift (TPD) causes occulting rays to scan the atmosphere in various occultation planes. Horizontal gradients along the ray (HGR) cause the bending of each ray to be different from calculations that assume spherical symmetry.

Using simulations, we show that HGR‐induced r.m.s. errors are larger than TPD‐induced r.m.s. errors in the lower troposphere only. TPD‐induced errors are more important in the stratosphere. We account for TPD and HGR using a multi‐plane two‐dimensional (2D) ray‐tracing observation operator. We show that bending angle and refractivity can be calculated more accurately with this 2D operator than an operator that assumes spherical symmetry. We use 6335 CHAMP and SAC‐C occultations as a validation. These occultations were processed by the Jet Propulsion Laboratory using geometrical optics and canonical transform methods. Our results indicate that analyses and 6‐hour forecasts can provide sufficiently accurate horizontal gradient information to the 2D operator. We show that the effects due to HGR can be satisfactorily simulated using ray tracing in one plane only. The effects due to TPD can be accounted for by considering a slanted profile which follows the tangent point trajectory. These results have important implications for the development of fast observation operators for data assimilation in numerical weather prediction. Copyright © 2004 Royal Meteorological Society