bluuebunny/crossref_metadata_2025 huggingface dataset:
Rational Choice, Personality, and HIV‐Preventive Behavior in the Presence of Opportunities1
Authors: Eifler Stefanie
Published: August 2006

In this paper, condom use or non‐use in sexual intercourse with casual partners is analyzed on the basis of ideas derived from the theory of planned behavior (Ajzen & Madden, 1986), which is combined with the general theory of crime (Gottfredson & Hirschi, 1990). An integrated model allows the assumption that persons who display low self‐control are likely to seek out opportunities to engage in sexual intercourse with casual partners and are likely to display attitudes and subjective norms favoring the non‐use of condoms. The study consists of an empirical examination of these assumptions. A standardized questionnaire (vignette technique) was presented to a quota sample of 837 German adults aged 18 to 65 years. Loglinear analyses were carried out to examine the integrative model. The results are discussed with regard to the effectiveness of the theoretical framework applied and with regard to previous research that has been conducted in this area.
The Use of Personality Chiasms in Stereotype Research1
Authors: De Vries Reinout E.
Published: August 2006

In this research, notions from research using personality chiasms (Hofstee & Arends, 1994) are combined with normative considerations on how stereotype research should be conducted (Judd & Park, 1993). On the one hand, this research seeks to improve on studies using personality chiasms that have ignored issues involved in establishing the accuracy of national or ethnic stereotypes (e.g., use of criterion ratings). On the other hand, this research goes beyond traditional stereotype research using personality traits in including neutral trait adjectives. The sample of this study consists of 159 Indigenous Fijians and 177 Indo‐Fijians. Hypotheses concerning the prevalence of stereotypical exaggeration, ethnocentrism, and insensitivity in Fiji are supported. Furthermore, outcomes of this research show that concerns about the effects of social desirability on stereotypical exaggeration are somewhat but not completely justified.
Understanding Exercise and Diet Motivation in Overweight Women Enrolled in a Weight‐Loss Program: A Prospective Study Using the Theory of Planned Behavior
Authors: Gardner Rebecca Ellis , Hausenblas Heather A.
Published: August 2006

The purpose of this study was to prospectively examine the utility of the theory of planned behavior (TPB) constructs for exercise and diet behavior with women enrolled in a 4‐week weight‐loss program. Sixty‐nine females participated in group exercise 3 times a week and they consumed a low‐calorie diet for 1 month. They completed baseline measures of exercise behavior, demographic variables, and the TPB constructs for exercise and diet at the start of the program. Adherence to the exercise and diet was recorded, along with pre‐ and post‐measurements of body composition. Significant decreases in body mass index, body fat percentage, and circumference measurements occurred from pre‐ to post‐program. Hierarchical multiple regression analyses revealed that diet adherence was predicted by intention. However, the TPB constructs failed to predict exercise adherence, exercise intention, and diet intention. These results are discussed in relationship to previous research, and recommendations for future studies with this special population are highlighted.
Effects of Thinking About Reasons and Actions on Intentions to Perform Health Behaviors
Authors: Millar Murray
Published: August 2006

This study examined the effects of directed thinking on intention to perform disease‐detection and health‐promotion behaviors. It was hypothesized that when participants thought about reasons for performing the behavior, they would have stronger intentions to perform health‐promotion behaviors than disease‐detection behaviors. Alternatively, when participants thought about actions, the difference in intention to perform health‐promotion and disease‐detection behaviors should not be found. This hypothesis was tested by directing some participants to think of reasons why either a disease‐detection or a health‐promotion behavior would be beneficial. Other participants were directed to think of as many actions as possible that would make either a health‐promotion or disease‐detection behavior enjoyable. The results supported the hypothesis.
Favorable Job Conditions and Perceived Support: The Role of Organizations and Supervisors1
Authors: Stinglhamber Florence , Vandenberghe Christian
Published: August 2006

Two studies were conducted to examine the linkages between favorable intrinsically (IS) and extrinsically satisfying (ES) job conditions, and perceived support from the organization (POS) and the supervisor (PSS). Using a sample of 427 employees, Study 1 showed through a longitudinal design that, controlling for PSS, both favorablc IS and ES job conditions exerted a significant effect on POS, while only favorable IS job conditions contributed to PSS when the effects of POS were controlled for. Study 2, conducted with a sample of 292 employees, showed that the organization's discretionary control over IS job conditions moderated the relationship between IS job conditions and POS, while supervisor's control over IS job conditions moderated the relationship between IS job conditions and PSS.
Adult Attachment and High‐Risk Sexual Behavior Among HIV‐Positive Patients
Authors: Ciesla Jeffrey A. , Roberts John E. , Hewitt Ross G
Published: August 2006

The present study investigated the relationship between adult attachment style and sexual behavior among HIV‐positive patients. HIV‐positive (HIV+) participants (N= 48) completed questionnaires assessing number of sexual partners, adult attachment, self‐esteem, and depressive symptoms. Results revealed that insecure attachment styles (particularly negative attachment representations of self and fearful attachment) were associated with having multiple sexual partners, including at‐risk HIV‐negative (HIV‐) partners. These relationships remained significant after controlling for sexual orientation, self‐esteem, and depressive symptomatology. These results suggest that interpersonal issues may play a key role in high‐risk sexual behavior among HIV+ individuals.
Implicit Theories of Organizational Power and Priming Effects on Managerial Power‐Sharing Decisions: An Experimental Study1
Authors: Coleman Peter T.
Published: August 2006

Over 60 years of research on participative leadership has documented the many benefits of power sharing in organizations. However, a common obstacle to power sharing is the unwillingness of those with power to share it. An experimental study is presented that investigated the effects of managers' implicit theories of power in organizations on their willingness to share power with subordinates. The study proposed that chronic differences in implicit power theories (the degree of competitive vs. cooperative beliefs and ideals regarding organizational power relations) would affect managers' decisions to share or withhold power. Subliminal priming was predicted to temporarily enhance the accessibility of these differences in implicit power theories, thereby fostering or inhibiting spontaneous decisions to share power. Results indicate that the subliminal priming of competitive theories of organizational power negatively influenced managers' immediate, spontaneous decisions to share power, whereas chronic differences in their implicit theories similarly affected their more systematic decisions to share power. The theoretical and applied contributions of the study are discussed.
Individual Reactions to New Technologies in the Workplace: The Role of Gender as a Psychological Construct
Authors: Venkatesh Viswanath , Morris Michael G. , Sykes Tracy Ann , Ackerman Phillip L.
Published: August 2006

Using the theory of planned behavior (TPB), individual reactions to a new technology and technology usage behavior were studied over a 12‐month period among 552 employees being introduced to a new computer‐based system in the workplace. When considering gender as a psychological construct by employing Bern's Sex Role Inventory (BSRI), important distinctions were revealed. Specifically, masculine gender‐typed individuals exhibited the same pattern as did men in previous research; feminine gender‐typed individuals were different from women in that they were influenced only by subjective norm and PBC. The balanced decision‐making process was observed only in the case of individuals categorized as androgynous. The high percentage of women who tested to be androgynous explains the divergence in results from the previous work, and provides evidence of changing gender roles for women in today's organizations and society.
Perceived Similarity, Expectation‐Reality Discrepancies, and Mentors' Expressed Intention to Remain in Big Brothers/Big Sisters Programs
Authors: Madia Benjamin P. , Lutz Catherine J.
Published: August 2006

Studies have begun to document the academic and psychosocial benefits of Big Brothers/ Big Sisters programs for at‐risk youth (Rhodes, Grossman, & Resch, 2000). However, investigators have noted a problem with mentor attrition (Meissen & Lounsbury, 1981). The purpose of the current study was twofold. First, we explored the relative importance of specific dimensions of perceived similarity (including similarity in attitudes, interests, race, and personality) as well as mentors' expectation‐reality discrepancies in predicting mentors' expressed intention to remain in Big Brothers/Big Sisters programs. Second, we examined a model whereby interpersonal attraction and relationship quality served as mediators of these associations. Our results suggest that perceived similarity in extraver‐sion as well as the discrepancy between mentors' ideal versus actual roles were significant predictors of mentors' expressed intention to remain in the relationship. Relationship quality and interpersonal attraction appeared to mediate these findings.
When Accurate Beliefs Lead to Better Lie Detection1
Authors: Forrest James A. , Feldman Robert S. , Tyler James M.
Published: August 2006

This study tested the hypothesis that people with accurate beliefs about the cues that predict deception are better at detecting deception only when those beliefs are cognitively available and activated. To test the hypothesis, participants viewed video fragments of people who were being either honest or dishonest. A questionnaire assessed participants' beliefs about the cues involved in deception, and activation of participants' belief cues was accomplished by manipulating suspicion. The results provided support for the hypothesis, where participants whose beliefs were activated and had accurate beliefs were better at detecting deception compared to other participants. Gender differences were also found, where lies communicated by women were more accurately detected than were lies communicated by men.
An Examination of the Actor‐Observer Effect in Young Drivers' Attributions for Their Own and Their Friends' Risky Driving
Authors: Harre Niki , Brandt Theo , Houkamau Carla
Published: August 2006

The attributions of 70 young drivers for their own and their friends' risky driving were examined using open‐ended questions to determine if there were self‐other differences consistent with the actor‐observer effect. Six response categories were created, 4 of which were rated as more dispositional than situational by a subsample of the participants and 2 of which were rated as more situational than dispositional. While the largely dispositional category “Showing off, acting cool” was used significantly more for friends than for self, and the largely situational “In a hurry, late” was used significantly more for self than for friends, there was only limited support for the actor‐observer effect overall. The participants also rated their friends as taking more risks than themselves. The actor‐observer differences are suggested to be influenced primarily by motivational factors and the context in which young people observe their friends' driving. New approaches to traffic safety interventions are suggested.
An Examination of Moderators of the Effects of Customers' Evaluation of Employee Courtesy on Attitude Toward the Service Firm1
Authors: Gotlieb Jerry , Levy Michael , Grewal Dhruv , Lindsey‐Mullikin Joan
Published: August 2006

Employee courtesy is recognized as an important dimension of customer service. This paper presents and tests a model suggesting that employee courtesy affects attitudes toward a service firm. Employee courtesy, the physical environment, and locus of causality are three important elements of a service experience that might affect attitude toward a service firm. The paper reports results of two experiments that found there was an interaction effect between employee courtesy and the physical environment on attitude toward the service firm. That is, the effect of employee courtesy on attitudes is more positive when the environment is evaluated favorably than when it is evaluated unfavorably. However, there were no interaction effects of locus of causality and courtesy on attitude toward the service firm. In the second study, there was a main effect from locus of causality on attitude toward the firm in that experiment. That is, participants with an internal locus of causality had a more favorable attitude toward the service firm than did participants with an external locus of causality.
Coping With Uncertainty: Superstitious Strategies and Secondary Control1
Authors: Case Trevor I. , Fitness Julie , Cairns David R. , Stevenson Richard J.
Published: August 2006

The aim of the present studies was to investigate the relationship between primary and secondary control and the use of superstitious strategies under conditions of uncertainty and stress. In the first study, 78 participants completed a chance‐determined card‐guessing task in which they were permitted to use a psychic's card selections instead of making their own card selections. Participants' use of a superstitious strategy (a psychic's selections) increased significantly with the perceived likelihood of failure, regardless of belief in psychic ability. A second study (N= 102) replicated these findings using a skill task. Overall, these data suggest that as the need to control outcomes becomes increasingly salient, the use of superstitious strategies may represent attempts at secondary control.
A Cross‐Cultural Evaluation of a Multidimensional and Hierarchical Model of Physical Self‐Perceptions in Three National Samples1
Authors: Hagger Martin S. , Asçi F. Hülya , Lindwall Magnus
Published: August 2006

A multidimensional and hierarchical model of self‐perceptions in the physical domain was evaluated in samples from 3 nations: Great Britain, Sweden, and Turkey. The Physical Self‐Perception Profile (PSPP; Fox & Corbin, 1989), was translated and tested for factorial and construct validity in each national sample. A first‐order confirmatory factor analysis (CFA) hypothesizing 4 latent factors representing the subdomains of sports competence, body attractiveness, physical condition, and physical strength was found to describe the PSPP data adequately for each national sample. A second‐order CFA model that hypothesized a general latent factor of physical self‐worth also exhibited good fit with the data from each sample, supporting the validity of the instrument in the national groups. Multi‐sample analyses provided support for both models across samples, although selected items exhibited disparate meanings. The subdomain mean scores were significantly higher in the British sample compared with the Swedish and Turkish samples, with the exception of the physical condition subscale, which was higher in the Swedish and Turkish samples. Overall, these findings support the factor structure of the hierarchical, multidimensional model of physical self‐perceptions across the national samples.
War‐Zone Exposure and Long‐Term General Life Adjustment Among Vietnam Veterans: Findings From Two Perspectives1
Authors: Vogt Dawne S. , King Daniel W. , King Lynda A. , Savarese Vincent W. , Suvak. Michael K.
Published: August 2006

This two‐part investigation examined associations between service in Vietnam and indices of long‐term general life adjustment using a national sample of male and female members of the Vietnam generation. In Study 1, we documented reasonably high levels of satisfaction and attainment among Vietnam veterans, levels that differed minimally, on average, from those who served elsewhere and those who never served in the military. In Study 2, dimensions of war‐zone stressor exposure were only marginally related to satisfaction and attainment, in contrast with research documenting strong relationships with psychopathol‐ogy. These findings support the importance of expanding our thinking about dimensions of mental illness and mental health.
Perceived Risk and Worry: The Effects of 9/11 on Willingness to Fly1
Authors: Bergstrom Rochelle L. , McCaul Kevin D.
Published: August 2006

Most decision‐making models rely on affect‐free variables to understand the decisions that people make. We tested an affectively‐loaded variable—worry—as a predictor of decision making in an affectively laden context: willingness to fly after 9/11. College students rated their willingness to fly to New York City or Washington, DC, in a study conducted 34 days after 9/11. They also recorded their beliefs about the likelihood that more terrorist attacks would occur, the severity of such attacks if they were to occur, and how much they worried about flying. Finally, they made these estimates for similar others. Results showed that worry was the most powerful predictor of one's own and similar others' willingness to fly. These findings suggest that models of how people make decisions may sometimes need to take feelings into account.
Work‐Group Membership (In)Stability and Survivors' Reactions to Organizational Downsizing1
Authors: Armstrong‐Stassen Marjorie , Wagar Terry H. , Cattaneo R. Julian
Published: August 2006

This longitudinal panel study investigated the interactive effect of work‐group membership stability and time on survivors' reactions to organizational downsizing. The participants were 159 nonmanagement employees of a federal government department. Survivors in moderate‐change work groups did not react more negatively to the downsizing. In fact, they reported a significant increase in job satisfaction, job security, job performance, and employee morale. Survivors who changed to different work groups expressed the least positive attitudes in the initial phase of the downsizing, but the most positive attitudes at the completion of the downsizing. Work‐group membership (in)stability was more likely to affect survivors' reactions to various aspects of their job over time than factors related to the work group itself.
Predicting Dieting Behavior by Using, Modifying, and Extending the Theory of Planned Behavior
Authors: Nejad Lillian M. , Wertheim Eleanor H. , Greenwood Kenneth M.
Published: August 2006

The theory of planned behavior (TPB) was used, modified, and extended to predict dieting intention and behavior. Female undergraduates (n= 256) responded to a survey assessing variables from the TPB and additional predictor variables. Seventy‐eight of these participants also completed a follow‐up questionnaire 3 months later that assessed their subsequent weight‐loss behavior. A model was developed for dieting using path analysis to assess the most significant paths to intention to diet and follow‐up dieting. In the final predictor model, 77% of the variance in intention to diet and 46% of the variance in follow‐up dieting were explained. The strongest predictor of intention to diet was direct attitude, and the strongest predictor of follow‐up dieting was prior dieting. This study also included a confirmatory analysis of the dieting model (n=117). Approximately 2/3 of the paths were confirmed, and 72% of the variance in intention was explained.
Black Applicants’ Reactions to Affirmative Action Plans: Influence of Perceived Procedural Fairness, Anticipated Stigmatization, and Anticipated Remediation of Previous Injustice1
Authors: Slaughter Jerel E. , Bulger Carrie A. , Bachiochi Peter D.
Published: August 2006

This research was conducted to understand why Black applicants might react negatively to affirmative action plans (AAPs) designed to benefit them. Black engineering students (N= 2,480) reacted to 1 of 8 AAPs, to which they were randomly assigned. Two manipulations were used to form the 8 different plans: plan content (eliminate discrimination, recruitment, training, weak preferential treatment) and plan frame (affirmative action vs. diversity). The effect of plan content on job‐pursuit intentions was mediated by perceived procedural fairness, anticipated remediation of injustice, and anticipated stigmatization. Job‐pursuit intentions were related to interactions between perceived fairness and anticipated remediation, between perceived fairness and anticipated stigmatization, and between plan content and respondent experiences with discrimination and racism. Plan frame affected only anticipated remediation of previous injustice. Theoretical and practical implications of these findings are discussed.
Depressed or Just Blue? The Persuasive Effects of a Self‐Diagnosis Inventory1
Authors: Raghubir Priya , Menon Geeta
Published: August 2006

A self‐diagnosis inventory is both a response instrument and a tool for an individual to assess his or her risk. Three experiments show that the manner in which a depression self‐diagnosis inventory is administered and constructed affects the manner in which a respondent interprets behavioral symptoms. This in turn affects (a) self‐reports of whether the symptoms apply to the respondent; (b) the respondent's perceived risk of depression; (c) the perceived controllability of the behavioral symptoms; and (d) the respondent's likelihood of seeking treatment. Theoretical implications of the content and format of self‐diagnosis inventories are discussed, as are implications for how to persuade people to seek assistance when they are at risk.
Equivocality and Escalation: A Replication and Preliminary Examination of Frustration1
Authors: Brecher Ellyn G. , Hantula Donald A.
Published: August 2006

An equivocality theory account of escalation of commitment was investigated using a computer simulated marketing scenario in a replication and extension of Hantula and DeNicolis Bragger (1999). Participants acted as marketing executives and invested money to promote sales of a new sneaker, and received high or low equivocality feedback from their investments for one phase and then received failure feedback in a second phase. Participants were videotaped throughout the experiment. Replicating previous research, participants receiving highly equivocal feedback invested a greater relative amount of money during failure than did those who received feedback low in equivocality. Furthermore, analyses of the videotapes for behaviors indicative of frustration showed that participants in both feedback groups displayed a greater degree of frustration while receiving failure feedback than during the first phase of the study. These data replicate and extend previous equivocality findings, but do not resolve the role of frustration in escalation unambiguously.
Collisional Spectroscopy in Structural Characterization of Melanins: I. A First Study on |C8H7ON|+· Ions Originating From Pyrolysis of Biosynthetic and Synthetic Tryptophan Melanins
Authors: ALLEGRI GRAZIELLA , BIASIOLO MONICA , PRISON GIAMPIETRO , PELLI BEATRICE , TRALDI PIETRO
Published: August 2006

The structural investigation of four bio‐ and synthetic melanins, obtained by the action of polyphenol oxidase from potatoes and Psalliota campestris mushrooms and of tyrosinase from Sepia officinalis on tryptophan, or by means of performic oxidation, has been carried out by thermal decomposition performed in the ion source of a mass spectrometer. The structural characterization of the ionic species |C8H7ON|+· common and abundant for all the examined compounds, has been obtained by accurate mass measurements and collisional spectroscopy. These mass spectrometric techniques have shown unequivocally for ionic species | C8H7ON| +· the structure of 2‐indolinone.
Biosynthetic Pathways of Pteridines and Their Association With Phenotypic Expression In Vitro in Normal and Neoplastic Pigment Cells From Goldfish
Authors: MASADA MASAHIRO , MATSUMOTO JIRO , AKINO MIKI
Published: August 2006

The distribution of GTP‐cyclohydrolase I, pyruvoyl tetrahydropterin (dysopropterin) synthase, and pyruvoyl tetrahydropterin reductase in goldfish erythrophores, melanophores, and erythrophoroma cells in vitro has been revealed by specific biochemical assays. The activity of pyruvoyl tetrahydropterin synthase in the erythrophores is nearly the same as that in rat kidney and pineal gland. Results of the simultaneous quantification of unconjugated pteridines (biopterin, sepiapterin, neopterin, and pterin) by HPLC indicate that the total amounts of these derivatives present in these cells and in the respective culture media are closely correlated with the activities of these enzymes. These findings imply that these cells are capable of the autonomous synthesis of pteridines, which most likely proceeds from GTP to 6‐lactoyl‐5,6,7,8‐tetrahydropterin (reduced sepiapterin), via dihydroneopterin triphosphate and pyruvoyl tetrahydropterin, through reactions catalyzed by these enzymes. A comparison of pteridine metabolism between clones of the stem cell type and the yellow‐pigmented clones induced from erythrophoroma cells suggests that brightly colored pigmentation involves two separate phases: the biosynthesis of pteridines and their deposition in the pigment organelles. The presence of the highly active pteridine‐synthesizing enzymes in melanophores and melanogenic erythrophoroma cells strongly suggests a loose commitment to the expression of pigment phenotypes in this species.
Pigmentary System of the Adult Alpine Salamander Salamandra atra aurorae (Trevisan, 1982)
Authors: PEDERZOLI AURORA , TREVISAN PIERLUIGI
Published: August 2006

The pigmentary system of skin from adult specimens of the amphibian urodele Salamandra atra aurorae was investigated by light microscope, electron microscope, and biochemical studies. Yellow (dorsum and head) and black (flank and belly) skin was tested.

Three chromatophore types are present in yellow skin: xanthophores, iridophores, and melanophores. Xanthophores are located in the epidermis whereas iridophores and melanophores are found in the dermis. Xanthophores contain types I, II, and III pterinosomes. Some pterinosomes are very electron‐dense.

Black skin has a single type of chromatophore: the melanophores. Some melanophores are located in the epidermis. In contrast to the dermal melanophores, these present, in addition to typical melanosomes, organelles with different morphology and vesicles having a limiting membrane and containing little amorphous material.

Both skin types present some pteridines and flavins, though they are qualitatively and quantitatively more abundant in yellow skin extracts.
Melanin Accelerates the Tyrosinase‐Catalyzed Oxygenation of p‐Hydroxyanisole (MMEH)
Authors: MENTER JULIAN M. , TOWNSEL MICHAEL E. , MOORE CYRIL L. , WILLIAMSON GEORGE D. , SOTERES BETTY JEAN , FISHER MICHAEL S. , WILLIS ISAAC
Published: August 2006

Although pigment melanin has long been thought of as “inert,” recent work has attested to its chemical reactivity. In this communication, we report that either commercial synthetic melanin prepared by persulfate oxidation of tyrosine (“Sigma melanin”) or sepia melanin extracted from cuttlefish markedly accelerates the in vitro oxygenation of p‐hydroxyanisole (MMEH), catalyzed by mushroom or B‐16 melanoma tyrosinase. Kinetics of 4‐methoxy‐1,2‐benzoquinone formation (λmax = 413 nm) or of molecular O2 uptake were biphasic, with an initial slow rate (“lag time”) followed by a fast linear increase. The biphasic response reflects an initial slow hydroxylation followed by a fast dehydrogenation. Added melanin markedly decreased the lag time but had little effect on subsequent dehydrogenation. Similar effects were observed for tyrosine itself. A complex between MMEH and melanin appears to be the “active” species in these reactions. The results indicate that melanin acts as an electron conduit, which accepts electrons from the substrate and transfers them to tyrosinase. The magnitude of the effect depends on the type of melanin as well as on its oxidation state. Kinetic analysis indicates that both melanins are very efficient at transferring electron to tyrosinase, and that Sigma melanin is roughly threefold more efficient than sepia melanin. The qualitative similarity of reaction between the synthetic and “natural” melanins suggests that the former may serve as a first approximation to the in vivo situation. On the other hand, the observed quantitative differences and the sensitivity of these results to the chemical state of melanin suggests that this methodology might eventually be adapted as a non‐destructive probe of melanin in situ. These results also hint at a “dark side,” of melanin, through which cytotoxic quinone formation may be facilitated.
Characterization of the Reflective Materials and Organelles in the Bright Irides of North American Blackbirds (Icterinae)
Authors: HUDON JOCELYN , MUIR ALISTER D.
Published: August 2006

The reflective materials in the iris stroma of bright‐irised American blackbirds (Icterinae, Emberizidae) and the red‐eyed vireo (Vireo olivaceus) (Vireonidae) were characterized using high‐performance liquid chromatography (HPLC) and diode‐array detection. Two purines, guanine and hypoxanthine, and two pteridines, leucopterin and xanthopterin, were detected in large amounts in all bright irides. The brown iris of the red‐winged blackbird (Agelaius phoeniceus) by comparison contained only small amounts of these and additional unidentified compounds. The absolute and relative amounts of light‐absorbing compounds in the iris varied somewhat among species of blackbirds with bright irides, and markedly within one species (brewer's blackbird, Euphagus cyanocephalus) between sexes and age classes that vary in eye color. Differences in the types, numbers, and sizes of pigment organelles in the irides appeared to underlie the differences in amounts of light‐absorbing compounds. Guanine was the most abundant light‐absorbing compound in all bright irides, accounting for about 90% of the total absorption at 250 nm. A wide range of concentrations of guanine, from 96 to 9 μg per iris, produced bright irides. The primary pigment organelles of pigment cells in bright irides were reflecting platelets, which typically appeared as open spaces on electron micrographs. In the red‐eyed vireo there were in addition red pterinosome‐like pigment organelles in the pigment cells on the anterior surface of the iris stroma. Guanine was present even in irides with no overt reflecting platelets.
Beneficial effects of melatonin in protecting against cyclosporine A‐induced cardiotoxicity are receptor mediated
Authors: Rezzani Rita , Rodella Luigi F. , Bonomini Francesca , Tengattini Sandra , Bianchi Rossella , Reiter Russel J.
Published: August 2006

Abstract:  Melatonin, the chief product secreted by pineal gland, is capable of reducing free radical damage by acting directly as a free radical scavenger, and indirectly, by stimulating of antioxidant enzymes. Cyclosporine A (CsA) is the most widely used immunosuppressive drug, but its therapeutic use has several side effects including, i.e. nephrotoxicity and cardiotoxicity. This study was designed to examine the beneficial effects of melatonin in preventing CsA‐induced cardiotoxicity. Additionally, we investigated the ability of melatonin to protect the rat heart via melatonin receptor. In one group of Wistar rats, melatonin (1 mg/kg/day i.p.) was administered concurrently with CsA (15 mg/kg/day s.c.) for 21 days. In another group of animals, melatonin was injected with CsA and luzindole, an antagonist of melatonin receptors. Oxidative stress in heart tissue homogenates was estimated using thiobarbituric acid reactive substances (TBARS), reduced glutathione levels and antioxidant enzyme activities including catalase and superoxide dismutase. CsA administration for 21 days produced elevated levels of TBARS, marked depletion of cardiac antioxidant enzymes and caused morphological alterations in myocardial fibers. Melatonin markedly reduced TBARS levels, increased the antioxidant enzyme levels and normalized altered cardiac morphology. The protective effects of melatonin were lost when the animals received the melatonin receptor antagonist. In conclusion our study shows that, (a) melatonin significantly reduces CsA cardiotoxicity, and (b) the reduction in CsA‐induced cardiotoxicity was mediated by the binding of melatonin to its membrane receptors.
Soluble CD40 Ligand Levels during Controlled Ovarian Hyperstimulation – A Possible Culprit of Systemic Inflammation
Authors: Orvieto Raoul , Schachter Benny , Yulzari‐Roll Vered , Marca Antonio La , Bar Jacob , Fisch Benjamin
Published: August 2006

Aim  To investigate the behavior and association of serum sex‐steroids and serum CD40 ligand in patients undergoing controlled ovarian hyperstimulation (COH) for in vitro fertilization (IVF).

Design  Prospective, observational study.

Setting  The IVF unit of an academic medical center.

Patients and methods  Blood was drawn three times during the COH cycle from 17 patients undergoing the long gonadotropin‐releasing hormone‐analog protocol: (i) day on which adequate suppression was obtained (Day‐S); (ii) day of or prior to administration of human chorionic gonadotropin (Day‐hCG); and (iii) day of ovum pick‐up (Day‐OPU). Levels of sex steroids and serum CD40 ligand were compared among the three time points.

Results  During gonadotropin treatment, serum ovarian sex steroids (estradiol, progesterone, free testosterone and androstenedione) significantly increased while CD40 ligand levels nonsignificantly decreased. After hCG administration, there was a significant increase in the levels of serum CD40 ligand, ovarian androgens, and progesterone, with a significant decrease in estradiol levels. No correlations were observed between CD40 ligand and ovarian sex‐steroid levels or other treatment variables.

Conclusion  The administration of hCG leads to activation of systemic inflammation, as reflected by CD40 ligand levels. This, in turn, may lead to the development of ovarian hyperstimulation syndrome via several mechanisms, including an increase in several angiogenic factors.
Multiple promoters regulate tissue‐specific alternative splicing of the human kallikrein gene, KLK11/hippostasin
Authors: Mitsui Shinichi , Nakamura Terukazu , Okui Akira , Kominami Katsuya , Uemura Hidetoshi , Yamaguchi Nozomi
Published: August 2006

The human kallikrein (KLK) family consists of 15 genes located on human chromosome 19q13.4. KLK11/hippostasinis a member of the kallikrein family and is expressed in various tissues. Two types of KLK11 isoforms, isoform 1 and isoform 2, have been predicted from cDNA sequences. Isoform 1 has been isolated from human hippocampus, whereas isoform 2 has been isolated from prostate. However, the regulation and characteristics of these isoforms are unknown. We identified the first three exons (1a, 1b, and 1c) by determining their transcription initiation sites. Exon 1b contained the initiation codon of isoform 2, and noncoding exons 1a and 1c contributed to isoform 1 mRNA. The dual luciferase promoter assay revealed three promoter regions, corresponding to the first exon of each isoform. Reverse transcription and PCR showed that exon 1a was expressed in the hippocampus, thalamus, and non‐central nervous system (CNS) tissues, whereas exon 1b was detected only in non‐CNS tissues. Exon 1c was observed in both CNS and non‐CNS tissues, except for salivary glands. In vitro mutagenesis revealed that the initiation codon for isoform 2 in exon 1b was functional. Isoform 2 had additional hydrophilic amino acids at the amino terminal and was secreted from the neuroblastoma cell line Neuro2a. Isoform 1 fused with green fluorescent protein (GFP) was distributed to cellular processes, whereas isoform 2–GFP was retained in the Golgi apparatus. We suggest that not only alternative splicing but also tissue‐specific use of multiple promoters regulate the expression and intracellular trafficking of KLK11/hippostasin isoforms.
EcR expression in the prothoracicotropic hormone‐producing neurosecretory cells of the Bombyx mori brain
Authors: Hossain Monwar , Shimizu Sakiko , Fujiwara Haruhiko , Sakurai Sho , Iwami Masafumi
Published: August 2006

The steroid hormone 20‐hydroxyecdysone (20E) initiates insect molting and metamorphosis through binding with a heterodimer of two nuclear receptors, the ecdysone receptor (EcR) and ultraspiracle (USP). Expression of the specific isoforms EcR‐A and EcR‐B1 governs steroid‐induced responses in the developing cells of the silkworm Bombyx mori. Here, analysis of EcR‐A and EcR‐B1 expression during larval‐pupal development showed that both genes were up‐regulated by 20E in the B. mori brain. Whole‐mount in situ hybridization and immunohistochemistry revealed that EcR‐A and EcR‐B1 mRNAs and proteins were exclusively located in two pairs of lateral neurosecretory cells in the larval brain known as the prothoracicotropic hormone (PTTH)‐ producing cells (PTPCs). In the pupal brain, EcR‐A and EcR‐B1 expression was detected in tritocerebral cells and optic lobe cells in addition to PTPCs. As PTTH controls ecdysone secretion by the prothoracic gland, these results indicate that 20E‐responsive PTPCs are the master cells of insect metamorphosis.
Critical roles of conserved carboxylic acid residues in pigeon cytosolic NADP+‐dependent malic enzyme
Authors: Chang Shuo‐Chin , Lin Kuan‐Yu , Chen Yu‐Jung , Lai Chin‐Hung , Chang Gu‐Gang , Chou Wei‐Yuan
Published: August 2006

Malic enzyme catalyses the reduction of NADP+ to NADPH and the decarboxylation of l‐malate to pyruvate through a general acid/base mechanism. Previous kinetic and structural studies differ in their interpretation of the amino acids responsible for the general acid/base mechanism. To resolve this discrepancy, we used site‐directed mutagenesis and kinetic analysis to study four conserved carboxylic amino acids. With the D257A mutant, the Km for Mn2+ and the kcat decreased relative to those of the wild‐type by sevenfold and 28‐fold, respectively. With the E234A mutant, the Km for Mg2+ and l‐malate increased relative to those of the wild‐type by 87‐fold and 49‐fold, respectively, and the kcat remained unaltered, which suggests that the E234 residue plays a critical role in bivalent metal ion binding. The kcat for the D235A and D258A mutants decreased relative to that of the wild‐type by 7800‐fold and 5200‐fold, respectively, for the overall reaction, by 800‐fold and 570‐fold, respectively, for the pyruvate reduction partial reaction, and by 371‐fold and 151‐fold, respectively, for the oxaloacetate decarboxylation. The activities of the overall reaction and the pyruvate reduction partial reaction of the D258A mutant were rescued by the presence of 50 mm sodium azide. In contrast, small free acids did not have a rescue effect on the activities of the E234A, D235A, and D257A mutants. These data suggest that D258 may act as a general base to extract the hydrogen of the C2 hydroxy group of l‐malate with the aid of D235‐chelated Mn2+ to polarize the hydroxyl group.
Water‐Soluble Constituents of Cudrania tricuspidata (Carr.) Bur.
Authors: Zheng Zong‐Ping , Liang Jing‐Yu , Hu Li‐Hong
Published: August 2006

In order to find new structural and biologically active compounds, the constituents of the bark of Cudrania tricuspidata (Carr.) Bur. were investigated and a new 6‐p‐hydroxybenzyltaxifolin glucoside, named tricusposide (compound 1), together with 16 known compounds, was isolated by solvent partition, macroporous adsorption resin AB‐8, silica gel, Sephadex LH‐20 chromatography. Using spectroscopic methods, the structures of the compounds were elucidated as 6‐p‐hydroxybenzyl taxifolin‐7‐O‐β‐D‐glucoside (compound 1), dihydroquerctin‐7‐O‐β‐D‐glucoside (compound 2), dihydrokaempferol‐3‐O‐β‐D‐glucoside (compound 3), dihydroquercetin (compound 4), peonoside (compound 5), sphaerobioside (compound 6), quercimeritrin (compound 7), genistein (compound 8), aromadendrin (compound 9), kaempferol (compound 10), genistin (compound 11), 3,4‐dihydroxystyryl alcohol (compound 12), sucrose (compound 13), 1,3,5,6‐tetrahydroxyxanthone (compound 14), gericudranin E (compound 15), gericudranin C (compound 16), and orobol (compound 17). Compounds 2–6, 8, 9, 12–14, and 17 were isolated from this genus for the first time.

(Managing editor: Wei Wang)
Costs and Risks of Segregating GM Wheat in Canada
Authors: Wilson William W. , Dahl Bruce
Published: August 2006

An analytical model was developed to explore prospective costs and risks of alternative testing strategies for a marketing system in Canada which markets both genetically modified (GM) and Non‐GM wheats. The problem is solved using stochastic optimization, base case results are defined, and sensitivities conducted to evaluate impacts of selected variables. Added costs include: testing, rejection, and a risk premium which is required for handlers to be indifferent between the current and the proposed dual system. Protocols would require testing at the point of loading at the primary elevator, and export elevator, and supplementing this information with some form of grower variety declaration. There are several sources of inherent risks in such a system. For buyers, the cumulative impact of these is the risk of receiving GM content in a Non‐GM shipment. For sellers, it is the risk of having a Non‐GM shipment rejected. For sellers, the risk of rejection was typically less than 2%, and for buyers, the risk was typically less than 0.02%.

Nous avons élaboré un modèle analytique pour explorer les coûts et les risques potentiels de la mise en place de nouvelles stratégies pour analyser le grain si le Canada décidait de commercialiser du blé génétiquement modifié (GM) et du blé non génétiquement modifié (NGM). Le problème est résolu à l'aide d'une optimisation stochastique; des scénarios de référence sont définis et des tests de sensitivité sont effectués pour évaluer l'impact de variables sélectionnées. Les coûts supplémentaires comprennent les coûts d'analyses, les coûts liés au rejet ainsi qu'une prime de risque exigée pour que les manutentionnaires demeurent indifférents entre le système actuel et le système double proposé. Les protocoles obligeraient la tenue d'analyses au point de chargement du silo primaire ainsi qu'au silo terminal, auxquelles s'ajouterait une certaine forme de déclaration du céréaliculteur sur la variété. Ce genre de système comporte plusieurs sources de risques inhérents. Pour les acheteurs, l'impact cumulatif est le risque de recevoir un chargement de blé NGM contenant du blé GM. Pour les vendeurs, c'est le risque qu'un chargement de blé NGM soit rejeté. Pour les vendeurs, le risque de rejet était généralement inférieur à 2%, et pour les acheteurs, le risque était généralement inférieur à 0.02%.
Martingale Restrictions and the Implied Market Price of Risk
Authors: Turvey Calum G. , Komar Sridar
Published: August 2006

The market price of risk is conceptually one of the most critical artifacts of modern finance, since it provides the linkage between equilibrium and arbitrage models of derivatives pricing. In this paper, the market price of risk is derived for options on live cattle futures contracts. It provides a technique to extract the implied market price of risk (iMPR), which is conceptually similar to that used in extracting implied volatilities. It is shown that the iMPR is not linear across strike prices as theory suggests it should.

Le prix de marché du risque est conceptuellement l'un des artéfacts les plus importants de la finance moderne puisqu'il établit le lien entre les modèles d'équilibre et les modèles d'évaluation par arbitrage de l'établissement des prix des dérivés. Dans le présent article, le prix de marché du risque est dérivé pour les options sur contrats à terme de bovins vivants. Il offre une technique pour extraire le prix de marché implicite du risque qui est conceptuellement similaire à celle utilisée pour extraire les volatilités implicites. Il est montré que le prix de marché implicite du risque n'est pas linéaire pour tous les prix de levée comme la théorie semble l'indiquer.
This Little Piggy Went to Market with a Passport: The Impacts of U.S. Country of Origin Labeling on the Canadian Pork Sector
Authors: Rude James , Iqbal Javed , Brewin Derek
Published: August 2006

This paper examines the potential impacts of U.S. mandatory country of origin labeling. North American hog and pork markets are represented as vertically related in a partial equilibrium non‐spatial model. A synthetic model is calibrated to historic data and then used to trace the program's added costs as they are passed through the market to determine who wins and who loses. The transactions costs reduce the welfare of all agents in the United States. Canadian welfare depends primarily on whether mixed supply chains continue to be accepted in the United States and trade in hogs continues. A closed border significantly reduces the welfare of Canadian hog producers and increases the welfare of Canadian pork processors.

Le présent article porte sur les répercussions éventuelles de l'étiquetage obligatoire du pays d'origine réclamée par les États‐Unis. Les marchés nord‐américains du porc vivant et de la viande de porc sont représentés comme étant verticalement liés dans un modèle non spatial d'équilibre partiel. Un modèle synthétique est étalonné avec des données historiques et est ensuite utilisé pour déterminer les coûts supplémentaires qu'occasionne le programme à mesure qu'ils sont répartis sur le marché pour déterminer les gagnants et les perdants. Les coûts de transaction diminuent le bien‐être de tous les agents aux États‐Unis. Le bien‐être au Canada dépend principalement de l'acceptation ou non des chaînes d'approvisionnement mixtes et de la continuité ou non du commerce du porc vivant. La fermeture des frontières diminue considérablement le bien‐être des producteurs de porcs canadiens et augmente celui des transformateurs de porcs canadiens.