2003年上半年铅市场评述及下半年市场预测

文章回顾了今年上半年国内外铅市场概况,并对下半年铅市场进行了展望。上半年全球精铅产量下降、消费回升,LME铅价底部逐步提高。下半年全球精铅消费将较大幅度回升,精铅供应将出现短缺,LME铅价将彻底摆脱410～450美元/t的底部区间,国内精铅产量、消费及出口均将增长,价格将随LME铅价走高而小幅上升。     

Cutting stress off at the pass: Reducing vigilance and responsiveness to social threat by manipulating attention.

Personality processes relating to social perception have been shown to play a significant role in the experience of stress. In 5 studies, the authors demonstrate that early stage attentional processes influence the perception of social threat and modify the human stress response. The authors first show that cortisol release in response to a stressful situation correlates with selective attention toward social threat. Second, the authors show in 2 laboratory studies that this attentional pattern, most evident among individuals with low self-esteem, can be modified with a repetitive training task. Next, in a field study, students trained to modify their attentional pattern to reduce vigilance for social threat showed lower self-reported stress related to their final exam. In a final field study with telemarketers, the attentional training task led to increased self-esteem, decreased cortisol and perceived stress responses, higher confidence, and greater work performance. Taken together, these results demonstrate the impact of antecedent-focused strategies on the late-stage consequences of social stress. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Social class, sense of control, and social explanation.

Lower social class is associated with diminished resources and perceived subordinate rank. On the basis of this analysis, the authors predicted that social class would be closely associated with a reduced sense of personal control and that this association would explain why lower class individuals favor contextual over dispositional explanations of social events. Across 4 studies, lower social class individuals, as measured by subjective socioeconomic status (SES), endorsed contextual explanations of economic trends, broad social outcomes, and emotion. Across studies, the sense of control mediated the relation between subjective SES and contextual explanations, and this association was independent of objective SES, ethnicity, political ideology, and self-serving biases. Finally, experimentally inducing a higher sense of control attenuated the tendency for lower subjective SES individuals to make more contextual explanations (Study 4). Implications for future research on social class as well as theoretical distinctions between objective SES and subjective SES are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Social Anxiety, Negative Affectivity, and Substance Use Among High School Students.

The literature regarding the relationship between adolescent social anxiety and substance use is sparse, and available studies have produced discrepant results. Similarly, negative affectivity is a mood-dispositional dimension that is infrequently considered in studies of substance use. The authors used dispositional structural equation modeling to examine the concurrent relationships of social anxiety and negative affectivity with adolescent substance involvement among 724 students in 1 southern California high school. The final model indicated that increased substance use was associated with having lower grade-point average, being male, being White, having higher levels of negative affectivity, and having lower levels of social anxiety. The findings confirm that negative affectivity is positively related to adolescent substance use, whereas social anxiety appears to be protective against substance involvement. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Confidence in Individual and Group Decision Making: When "Two Heads" Are Worse Than One.

The authors investigated students' accuracy and confidence judgments for course-related material in college classrooms. Under conditions of group work and instructor feedback, students produced higher exam accuracy scores working in groups than alone but at a cost of increased confidence for groups' wrong answers. Groups' high confidence for wrong answers generated the case when "two heads are worse than one." Students participating in groups that arrived at wrong exam answers gave higher confidence when wrong and lower confidence when correct for repeated items on a final exam. "Two heads" groups when wrong had no adverse effect on students' accuracy for repeated exam items. An intervention of lecture and readings on confidence calibration, metamemory, and overconfidence did not improve the students' accuracy-confidence judgments. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

College students’ social justice interest and commitment: A social-cognitive perspective.

In this study, the authors examined the degree to which social-cognitive career theory (SCCT; R. W. Lent, S. D. Brown, & G. Hackett, 1994) explained the development of social justice interest and commitment. Data from 274 college students and latent variable path modeling were used to test theoretically and empirically derived SCCT direct and indirect effects structural models. The direct effects model estimated the direct effect of social supports and barriers on social justice commitment and the indirect effects model estimated the effect of social supports and barriers indirectly through self-efficacy. Overall, the present findings supported the use of SCCT within the social justice domain, as social justice self-efficacy and outcome expectations were useful in explaining the development of college students’ social justice interest and commitment. The present findings supported the indirect effects model of social justice interest and commitment over the direct effects model. Finally, unique to prior tests of SCCT in vocational and academic domains, social supports and barriers exhibited an indirect effect on commitment through outcome expectations. Study limitations, future directions for research, and implications for facilitating college students’ social justice interest and commitment are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Guidelines and feedback in information exchange: The impact of behavioral anchors and descriptive norms in a social dilemma.

Exchanging information through a shared database is a social dilemma. Each member of a work group saves costs by not contributing any information and by using the database only to retrieve information that was contributed by others. But if all people act according to this strategy, then the database is empty and useless for each group member. This article describes how standards influence people's behavior in this information-exchange dilemma. Based on assumptions about anchoring processes and processes of social comparison, the authors expect guidelines (as anchors) and feedback about others' behavior (as social standards) to influence people's information exchange. The first experiment indicates that arbitrary guidelines serve as behavioral anchors and influence people's contribution behavior-but only if the guidelines are made salient enough. The second experiment shows that bogus feedback about teammates' high or low contribution rates provoke the participants to conform to the behavior of the others. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

New methods for new questions: Obstacles and opportunities.

Two forces motivate this special section, "New Methods for New Questions in Developmental Psychology." First are recent developments in social science methodology and the increasing availability of those methods in common software packages. Second, at the same time psychologists' understanding of developmental phenomena has continued to grow. At their best, these developments in theory and methods work in tandem, fueling each other. Newer methods make it possible for scientists to better test their ideas; better ideas lead methodologists to techniques that better reflect, capture, and quantify the underlying processes. The articles in this special section represent a sampling of these new methods and new questions. The authors describe common themes in these articles and identify barriers to future progress, such as the lack of data sharing by and analytical training for developmentalists. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

High-yield expression, purification, and characterization of active, soluble Bacteroides fragilis metallo-beta-lactamase, CcrA

Two new areas of anchor development are biodegradable anchors and "mini" anchors. The group of biodegradable anchors tested include the Bio-Anchor, LactoSorb, Biofix, Bio-Statak, Mini Screw suture anchor, DePuy 4.5 molded, DePuy 4.5 machined, DePuy 3.5 machined, TAG Wedge 4, TAG Rod 2, TAG Wedge 3, TAG Wedge 2, and Stealth. "Mini anchors" have drill holes or minor diameters of < 2.2 mm. Those tested include the Mini Revo and Bio-Anchor, miniHarpoon, mini Mitek and Fast in 3, Statak 1.5 and 2.5, SB 2 and PeBA 3, Corkscrew 5, Corkscrew 3.5, and Fastak A2, Ogden 2.5, TAG Wedge 2, ROC 1.9, and Questus 2.5. Additional anchors tested that fit neither category include the Anspach, Questus 3.5 and 5.0, SB 3 and PeBA-C, Ogden 3.5, Fast in 4, Ultrafix, and the ROC 3.5, ROC 2.8, ROC 2.3, and ROC XS. An anchor comparison, using an established protocol in fresh porcine femurs, recorded failure strength, failure mode, eyelet size, minor and major diameters, and drill hole sizes. Except for the Bio-Anchor and TAG Wedge 2, biodegradable anchors tend to be larger to compensate for their lower strength relative to metal. Biodegradable screw anchors' predominant failure mode was eyelet cutout, whereas biodegradable nonscrew anchors failed to predominantly by anchor pullout. From an initial mechanical perspective, these biodegradable anchors perform acceptably. Both biodegradable and "mini" anchors include screw and nonscrew designs. As expected, screw designs perform well and generally fail at higher loads than nonscrew anchors. Although biodegradable anchors, as a group, are not as strong as metal anchors, they are stronger than the sutures for which they are designed. The move to smaller ("mini") and biodegradable anchors is supported by these data. Whether an anchor fails at twice the suture breaking strength or 10 times the suture breaking strength should make no difference.     

Less power or powerless? Egocentric empathy gaps and the irony of having little versus no power in social decision making.

The authors investigate the effect of power differences and associated expectations in social decision making. Using a modified ultimatum game, the authors show that allocators lower their offers to recipients when the power difference shifts in favor of the allocator. Remarkably, however, when recipients are completely powerless, offers increase. This effect is mediated by a change in framing of the situation: When the opponent is without power, feelings of social responsibility are evoked. On the recipient side, the authors show that recipients do not anticipate these higher outcomes resulting from powerlessness. They prefer more power over less, expecting higher outcomes when they are more powerful, especially when less power entails powerlessness. Results are discussed in relation to empathy gaps and social responsibility. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Tensile Behavior of FRP Tendons for Prestressed Ground Anchors

The research work reported in this paper involves investigation of the tensile behavior of fiber-reinforced polymer (FRP) ground anchors. Variables of the tests on the anchor models were anchor fixed length, tendon type, and tendon constituent. Sixteen monorod and four multirod grouted aramid FRP (AFRP) (Arapree and Technora) and carbon FRP (CFRP) (CFCC and Leadline) anchors were tested according to standard methods of tensile tests and sustained load tests under different load levels. Test results indicated that AFRP Arapree and Technora monorod anchors showed higher displacement and slip in comparison with CFRP CFCC and Leadline anchors. Technora anchors failed because of the detaching of winding fibers from the core of the rod. CFRP anchors had a higher tensile capacity and lower creep displacement than AFRP anchors. All the tested CFRP monorod and FRP multirod anchors with a 1,000-mm fixed length appeared to have an acceptable tensile behavior according to existing codes. Creep behavior appeared to control the long-term tensile capacity of prestressed FRP ground anchors. The recommended working load for prestressed FRP ground anchors is 0.40fpu for AFRP rods and 0.50fpu for CFRP rods, where fpu is the ultimate load or strength of anchor tendons.     

Investigation of Bid Price Competition Measured through Prebid Project Estimates, Actual Bid Prices, and Number of Bidders

Many practitioners today are faced with the task of advising clients on matters that may affect the number of project bidders. An appropriate question may be, does a restriction of bidder participation negatively impact project costs through limiting competition, and to what degree? Intuition and anecdotal evidence suggest that with an increase in the number of bidders vying for a project, the more competitive the low bid offer will be. There is little published evidence and analysis on bid competition impacting cost-effectiveness, although there are numerous reports replete with arguments, assumptions, anecdotal evidence, and bias. This paper critically evaluates public projects, bid under a condition of free, open, and unfettered competition. This paper presents a quantitative analysis of the impact of reduced competition on project bid prices. By selecting a single building type, designed by a single firm, with prebid estimates prepared from the same estimating database, over a limited time period, the investigation attempts to control model variance. The study found that reducing the number of bidders will result in increased project bid prices.     

When war comes to men's lives: Life-course patterns in family, work, and health.

Men generally come to military service at a time of youth. However, World War II expanded the period of service eligibility from age 18 to the late 30s. Each year of delay in entry promised a smaller return from military service (economic and job benefits) and a greater risk of life disruption and related costs. Using longitudinal data from the L. M. Terman (1925) and Terman and M. Oden (1959) studies, the authors examine whether social disruptions resulting from late service entry increased the risk of adverse change in adult health. Apart from preservice factors, the authors found that the late-mobilized men were at greatest risk of negative trajectories on physical health. Work-life disadvantages account in part for this health effect. Pathways that link stress and physical decline are discussed in relation to social disruption. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Review of Suicide and homicide.

Reviews the book, Suicide and homicide by Andrew F. Henry and James F. Short (see record 1965-08423-000). This book treats suicide and homicide as dependent variables and seeks to relate them to the business cycle, forms and degrees of social control, and aggressive tendencies against self or others. In five appendices the authors appraise previous research, examine statistical techniques for studying business cycles, and use these techniques to study the relations between cycles of suicides and of business, and offenses against property. The authors conclude that suicide rises in depression and falls in prosperity whereas homicide rises in prosperity and falls during depression. Both these tendencies are associated with social status-suicide with high and homicide with low status. As regards sociological variables, the authors study what they call "strength of the relational system" defined in terms of marital status, urban-rural residence, and ecological distribution. They conclude that the greater the strength of the relational system, the lower the suicide rate and the higher the homicide rate. This ambitious work aims to build on Durkheim's theory and the empirical research of more recent Americans. The interrelation of the types of variables considered by the authors seeks to solve questions of the association of superego structure with the combined effect of economic stress, social status, and the strength of the relational system. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A threshold approach to understanding the origins of attachment disorganization.

Disorganized attachment in infancy is known to predict a wide range of maladaptive outcomes, but its origins are poorly understood. Parental lack of resolution concerning loss or trauma has been proposed to result in atypical parenting behaviors, which in turn have a disorganizing effect on the parent-child relationship. The authors review the evidence for this transmission pathway, considering other factors (e.g., social environment, child characteristics) that might enrich understanding of the antecedents of disorganization. A threshold approach is proposed to explain (a) why different parental behaviors are linked to disorganization depending on prevailing social conditions and (b) why certain children appear more vulnerable to forming a disorganized attachment relationship. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Infant care decisions and attachment security: The Canadian Transition to Child Care Study.

To examine the family and child factors associated with child care decisions, 189 infants (aged 2–30 mo) were visited in their homes 3 wks before starting full-time out-of-home care and were followed for 6 mo (or its equivalent for parent-care families). Employed mothers who preferred to stay home were more depressed, and their children were more likely to experience unstable care than those who were working and wanted to work. Early entry was related to higher household income, less maternal depression and use of family home care as opposed to centre care. Age of entry, and type, stability, or quality of care were not related to attachment security but children with less sensitive mothers using extensive out-of-home care were least secure. Difficult temperament infants were more likely to experience insecure mother-infant relationships, but extensive use of out-of-home care buffered this effect. Findings provide strong support for the hypothesis that psychological and social characteristics play a significant role in child care decisions, in the stability of care, and in developmental outcomes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Using item response theory to understand comorbidity among anxiety and unipolar mood disorders.

The authors hypothesized that anxiety and unipolar mood disorders are often comorbid because each disorder indicates a broad, higher order factor. In a clinical subsample of the nationally representative National Comorbidity Survey participants (N?=?251), a one-factor model fit the correlations among 7 dichotomous anxiety and unipolar mood diagnoses. Following the lead provided by literature on the structure of emotional and behavioral problems in children, we labeled this factor internalizing. Item response theory was used to explore how each diagnosis mapped onto the internalizing factor. The test information function derived from the 7 diagnoses suggested that they measure primarily the higher end of the factor. In addition, very high scores on internalizing (meeting criteria for 6–7 disorders) were associated with increased social costs, a phenomenon not well captured by the "comorbidity" concept. The results underscore the need to develop clinical assessment instruments that span the full range of the internalizing factor and measure both the shared and distinctive features of anxiety and unipolar mood disorders in a graded, continuous fashion. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attitudes and beliefs toward mammography among women using an urban public hospital

Although overall use of mammography is steadily increasing, low-income and minority women consistently have relatively lower screening rates than white, middle-class women. To assess the mammography-seeking behavior of low-income women using an urban public hospital, this study sought to understand why women in this population decide whether or not to obtain a screening mammogram. Two qualitative techniques, elicitation interviews and focus groups, were used to develop an understanding of attitudes, concerns, and barriers of this group relative to mammography. Fear, embarrassment, susceptibility to breast cancer, inconvenience, cost, concerns about efficacy of mammography, fear of acquiring cancer, and scheduling difficulties were identified as important concerns. "People in the news" were the most influential social referents for mammography decision making, followed by physicians, family members, and friends. The insights gained from these women will assist in developing interventions that encourage mammography-seeking behavior by low-income women.     

Disconnecting outcomes and evaluations: The role of negotiator focus.

Three experiments explored the role of negotiator focus in disconnecting negotiated outcomes and evaluations. Negotiators who focused on their target prices, the ideal outcome they could obtain, achieved objectively superior outcomes compared with negotiators who focused on their lower bound (e.g., reservation price). Those negotiators who focused on their targets, however, were less satisfied with their objectively superior outcomes. In the final experiment, when negotiators were reminded of their lower bound after the negotiation, the satisfaction of those negotiators who had focused on their target prices was increased, with outcomes and evaluations becoming connected rather than disconnected. The possible negative effects of setting high goals and the temporal dimensions of the disconnection and reconnection between outcomes and evaluations are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Behavioral anchors as a source of bias in rating.

Behavioral anchors may affect the way that raters process information about ratees, and may in some cases be a source of bias in rating. This study tested the hypothesis that the presence of behavioral anchors that closely matched behaviors actually observed by raters would bias performance ratings. Subjects (N?=?180) viewed videotaped lectures and rated them, using scales that contained examples of either good or bad performance that had actually occurred on the tapes, but that were not representative of the ratee's overall performance. One half of the subjects read the scales before viewing the lectures; the remaining subjects read the scales only after viewing the lectures. There was a significant scale effect, but no Scale?×?Order interaction; ratings were biased in the direction of unrepresentative anchors. These results suggest that behavioral anchors can be a source of bias in ratings and they may lead to biased recall, but they probably do not bias the observation and encoding of ratee behavior. Our results suggest that behaviorally anchored scales are not necessarily more objective or less prone to bias than are scales without behavioral anchors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)