Home About us Contact
|
Home About us Contact | ||
|
|
||
Convergent
Terms modified by Convergent Selected AbstractsThe Development of a Convergent and Efficient Enantioselective Synthesis of the Bengamides via a Common Polyol IntermediateHELVETICA CHIMICA ACTA, Issue 12 2002Robert An efficient, general synthetic route to the bengamide family of antitumor agents from a common polyol thioester is described. Consecutive aldol condensations afford the protected polyol thioester side chain suitable for coupling to the bengamides. A novel chiral-phase-transfer-catalyzed enantioselective alkylation affords the properly functionalized caprolactams required for the synthesis of more-complex members of the bengamide family. Use of the methyl 2-naphthyl ether protecting group, compatible with the boron Lewis acids required for enantioselective aldol condensation, allows direct access to all the bengamides. [source] A psychometric evaluation of the Chinese version of the stage of change-readiness and treatment-eagerness scaleJOURNAL OF CLINICAL NURSING, Issue 17 2009Mei-Yu Yeh Aims., The present study analysed the psychometric properties of a Chinese version of the stage of change-readiness and treatment-eagerness scale among alcohol-dependent patients and investigated whether a three-factor structure fit the data. Background., The stage of change-readiness and treatment-eagerness scale is a 19-item instrument designed to measure alcohol-dependent patients' motivation for change. However, this instrument had not been translated and validated for use in Taiwan. Design., Survey. Methods., A sample of 161 alcohol-dependent patients receiving alcohol-related treatment in psychiatric hospital outpatient and inpatient units was included. Confirmatory factor analyses were conducted on three-factor measurement models of the stage of change-readiness and treatment-eagerness scale. Results., Confirmatory factor analyses supported the presence of a three-factor modified model (ambivalence, recognition and taking steps) among alcohol-dependent patients. Higher internal item consistency was found for the recognition and taking step factors, while the ambivalence factor was shown to have lower internal consistency. Convergent, discriminant and concurrent validity were obtained for the assessment of severity of alcohol dependence. Conclusions., The results indicated that the 11-item, three-factor modified Chinese version of the stage of change readiness and treatment eagerness scale provided best goodness of fit for the data in this study. This study demonstrated that the Chinese version of the stage of change readiness and treatment eagerness scale is a reliable and valid self-report measure for the assessment of changing motivation in alcohol-dependent patients. Relevance to clinical practice., The Chinese version of stage of change readiness and treatment eagerness scale is applicable for use in clinical treatment and research, predicting motivation for change and evaluating intervention outcomes in Taiwan. [source] Development and validation of the chinese rehearsal scale for preadolescent chinese children,,§JOURNAL OF CLINICAL PSYCHOLOGY, Issue 4 2010Fiona C.M. Ling Abstract Roger (1997) defined rehearsal as "the tendency to rehearse or ruminate on emotionally upsetting events" (p. 71). The Rehearsal Scale for Children,Chinese (RSC-C) was developed from the original 14-item Rehearsal Scale of the Emotion Control Questionnaire (Roger & Nesshoever, 1987) after translation and modification for Hong Kong Chinese preadolescents (aged 6,12 years). Confirmatory factor analysis using structural equation modeling revealed that with 1 item deleted from the original scale, the RSC-C possessed good internal validity and satisfactory test-retest reliability within a 1-year period. The new 13-item RSC-C also showed good external validity and internal reliability (,=.76). Convergent and discriminant validity was evidenced against the Emotional Problem and the Prosocial Behavior Subscales of the Strengths and Difficulties Questionnaire (Goodman, 1997), respectively. No gender differences in rehearsal scores were found. It was concluded that the 13-item RSC-C could be useful for measuring rehearsal in Chinese preadolescents. © 2010 Wiley Periodicals, Inc. J Clin Psychol 66: 1,10, 2010. [source] Construct validity of the adjustment scales for children and adolescents and the preschool and kindergarten behavior scales: Convergent and divergent evidencePSYCHOLOGY IN THE SCHOOLS, Issue 6 2002Gary L. Canivez Construct validity (convergent and divergent) of the Adjustment Scales for Children and Adolescents (ASCA; McDermott, Marston, & Stott, 1993) and the Preschool and Kindergarten Behavior Scales (PKBS; Merrell, 1994a) is presented. Regular classroom teachers (n = 38) randomly selected 5- and 6-year-old children (N = 123) and rated them on the ASCA and PKBS in counterbalanced order. Convergent evidence of construct validity was observed for the PKBS Externalizing Problems scale and the ASCA Overactivity syndrome. Divergent evidence of construct validity was provided for the PKBS Externalizing Problems scale and ASCA Underactivity syndrome. Convergent and divergent evidence of construct validity for the PKBS Internalizing Problems scale and ASCA Overactivity and Underactivity syndromes was mixed. Results were identical to those of Canivez and Bordenkircher (2002). © 2002 Wiley Periodicals, Inc. Psychol Schs 39: 621,633, 2002. [source] Convergent and concurrent validity of two measures of phonological processingPSYCHOLOGY IN THE SCHOOLS, Issue 5 2002J. Michael Havey The purposes of this study were to determine the degree to which two measures of phonological awareness/ability (Test of Phonological Awareness; Comprehensive Test of Phonological Processing) correlate with each other and with a measure of reading (Letter-Word Identification), and to determine which of the individual measures of phonological ability best predict early reading skill in kindergarten children. With one exception, all correlations among measures of phonological awareness/ability were significant. In addition, all correlations among the phonological awareness measures and the reading measure were significant. Multiple regression analyses revealed that the combination of all predictor variables accounted for approximately 51% of the variability in scores on the Woodcock Letter-Word Identification subtest. The Phonological Awareness and the Rapid Naming composites of the CTOPP were the best predictors of performance on the measures of word identification. © 2002 Wiley Periodicals, Inc. [source] Measurement of coping and stress responses in women with breast cancerPSYCHO-ONCOLOGY, Issue 12 2006Bruce E. Compas Abstract The development of the Responses to Stress Questionnaire-cancer version (RSQ-CV) to assess coping with and responses to the stress of breast cancer is described. The RSQ-CV was completed by 232 women with breast cancer near the time of their diagnosis. Confirmatory factor analyses verified a model that includes three voluntary coping factors (primary control engagement coping, secondary control engagement coping, disengagement coping) and two involuntary stress response factors (involuntary engagement, involuntary disengagement). Internal consistency reliability, and stability over 12 weeks for the five factors were adequate to excellent. Convergent and discriminant validity was examined through correlations with measures of intrusive thoughts, avoidance, and dimensions of perceived control. Significant correlations with symptoms of anxiety and depression are also reported. Applications of the RSQ-CV for research with breast cancer patients are discussed. Copyright © 2006 John Wiley & Sons, Ltd. [source] ChemInform Abstract: Convergent and Stereoselective Synthesis of Trisubstituted (E)-Alkenyl Bromides and Iodides via ,-Oxido Phosphonium Ylides.CHEMINFORM, Issue 18 2009David M. Hodgson Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] In vivo imaging of microglial cell traffickingACTA OPHTHALMOLOGICA, Issue 2009M PAQUES Purpose Microglial cells (MCs) are active sensors of neural tissues that are rapidly mobilized upon disruption of homeostasis. OUr goal was to observe in vivo the migration of MCs, which has not been done yet. Methods Following acute laser damage, the behavior of MCs in the retina of adult Cx3cr1gfp/+ and gfp/gfp mice was observed noninvasively using time-lapse confocal scanning laser ophthalmoscopy. Observation were done at various time-points up to 8 days after laser damage. Results Focal damage elicite prompt migratory response of MCs within 200 to 400 µm around laser burns. This migratory response was preceded in all case by dendritic reorientation. Convergent and nonconvergent migration were observed. Such migratory activity persisted several days after laser damage. At day 8, the microglia network was restored and microglial locomotion had ceased. Conclusion To our knowledge, this is the first observation of microglial locomotion in vivo. A Morphological evidence of microglial activation starts with dendritic reorganization. Migrating cells were only of the dendritic type (i.e. not ameboid). There appears to be a notable heterogeneity in the locomotor response of MCs. MCs within and around scars remain highly motile and mobile several days after laser damage. [source] A Convergent, Versatile Route to Two Synthetic Conjugate anti-Toxin Malaria Vaccines.CHEMINFORM, Issue 47 2004Peter H. Seeberger No abstract is available for this article. [source] Free Radical-Mediated Aryl Amination and Its Use in a Convergent [3 + 2] Strategy for Enantioselective Indoline ,-Amino Acid Synthesis.CHEMINFORM, Issue 22 2003Rajesh Viswanathan Abstract For Abstract see ChemInform Abstract in Full Text. [source] A Convergent, Flexible Synthesis of 1,3-Dienes.CHEMINFORM, Issue 44 2002Marie Lusinchi Abstract For Abstract see ChemInform Abstract in Full Text. [source] Refining and validating the Social Interaction Anxiety Scale and the Social Phobia ScaleDEPRESSION AND ANXIETY, Issue 2 2009R. Nicholas Carleton M.A. Abstract Background: The Social Interaction Anxiety Scale and Social Phobia Scale6 are companion measures for assessing symptoms of social anxiety and social phobia. The scales have good reliability and validity across several samples,3, 6 however, exploratory and confirmatory factor analyses have yielded solutions comprising substantially different item content and factor structures. These discrepancies are likely the result of analyzing items from each scale separately or simultaneously. The current investigation sets out to assess items from those scales, both simultaneously and separately, using exploratory and confirmatory factor analyses in an effort to resolve the factor structure. Methods: Participants consisted of a clinical sample (n5353; 54% women) and an undergraduate sample (n5317; 75% women) who completed the Social Interaction Anxiety Scale and Social Phobia Scale, along with additional fear-related measures to assess convergent and discriminant validity. Results: A three-factor solution with a reduced set of items was found to be most stable, irrespective of whether the items from each scale are assessed together or separately. Items from the Social Interaction Anxiety Scale represented one factor, whereas items from the Social Phobia Scale represented two other factors. Conclusion: Initial support for scale and factor validity, along with implications and recommendations for future research, is provided. Depression and Anxiety, 2009. © 2009 Wiley-Liss, Inc. [source] The Illness/Injury Sensitivity Index: an examination of construct validityDEPRESSION AND ANXIETY, Issue 6 2006R. Nicholas Carleton M.A. Abstract The 11-item Illness/Injury Sensitivity Index [ISI; Taylor, 1993: J Behav Ther Exp Psychiatry 24:289,299] measures fears of injury and illness and has the potential to delineate some mechanisms underlying anxiety-associated chronic health conditions. In a principal components analysis in 2005, Carleton et al. [2005a: J Psychopathol Behav Assess 27:235,241] indicated that a two-factor solution (Fear of Injury and Fear of Illness) best explained the structure of the ISI. The primary purpose of this study was to examine the structural and construct validity of the ISI. Results supported a two-factor solution after removal of two overinclusive items. Although the measure demonstrated good factorial validity, convergent and discriminant validity require further evaluation. In addition, a substantial correlation with fear of pain suggests a shift in our perspective on what constitutes a fundamental fear. Future research implications are discussed. Depression and Anxiety 23:340,346, 2006. © 2006 Wiley-Liss, Inc. [source] A low-dimensional physically based model of hydrologic control of shallow landsliding on complex hillslopesEARTH SURFACE PROCESSES AND LANDFORMS, Issue 13 2008Ali Talebi Abstract Hillslopes have complex three-dimensional shapes that are characterized by their plan shape, profile curvature of surface and bedrock, and soil depth. To investigate the stability of complex hillslopes (with different slope curvatures and plan shapes), we combine the hillslope-storage Boussinesq (HSB) model with the infinite slope stability method. The HSB model is based on the continuity and Darcy equations expressed in terms of storage along the hillslope. Solutions of the HSB equation account explicitly for plan shape by introducing the hillslope width function and for profile curvature through the bedrock slope angle and the hillslope soil depth function. The presented model is composed of three parts: a topography model conceptualizing three-dimensional soil mantled landscapes, a dynamic hydrology model for shallow subsurface flow and water table depth (HSB model) and an infinite slope stability method based on the Mohr,Coulomb failure law. The resulting hillslope-storage Boussinesq stability model (HSB-SM) is able to simulate rain-induced shallow landsliding on hillslopes with non-constant bedrock slope and non-parallel plan shape. We apply the model to nine characteristic hillslope types with three different profile curvatures (concave, straight, convex) and three different plan shapes (convergent, parallel, divergent). In the presented model, the unsaturated storage has been calculated based on the unit head gradient assumption. To relax this assumption and to investigate the effect of neglecting the variations of unsaturated storage on the assessment of slope stability in the transient case, we also combine a coupled model of saturated and unsaturated storage and the infinite slope stability method. The results show that the variations of the unsaturated zone storage do not play a critical role in hillslope stability. Therefore, it can be concluded that the presented dynamic slope stability model (HSB-SM) can be used safely for slope stability analysis on complex hillslopes. Our results show that after a certain period of rainfall the convergent hillslopes with concave and straight profiles become unstable more quickly than others, whilst divergent convex hillslopes remain stable (even after intense rainfall). In addition, the relation between subsurface flow and hillslope stability has been investigated. Our analyses show that the minimum safety factor (FS) occurs when the rate of subsurface flow is a maximum. In fact, by increasing the subsurface flow, stability decreases for all hillslope shapes. Copyright © 2008 John Wiley & Sons, Ltd. [source] Predators temper the relative importance of stochastic processes in the assembly of prey metacommunitiesECOLOGY LETTERS, Issue 11 2009Jonathan M. Chase Abstract Communities assemble through a combination of stochastic processes, which can make environmentally similar communities divergent (high ,-diversity), and deterministic processes, which can make environmentally similar communities convergent (low ,-diversity). Top predators can influence both stochasticity (e.g. colonization and extinction events) and determinism (e.g. size of the realized species pool), in community assembly, and thus their net effect is unknown. We investigated how predatory fish influenced the scaling of prey diversity in ponds at local and regional spatial scales. While fish reduced both local and regional richness, their effects were markedly more intense at the regional scale. Underlying this result was that the presence of fish made localities within metacommunities more similar in their community composition (lower ,-diversity), suggesting that fish enhance the deterministic, relative to the stochastic, components of community assembly. Thus, the presence of predators can alter fundamental mechanisms of community assembly and the scaling of diversity within metacommunities. [source] The merging of community ecology and phylogenetic biologyECOLOGY LETTERS, Issue 7 2009Jeannine Cavender-Bares Abstract The increasing availability of phylogenetic data, computing power and informatics tools has facilitated a rapid expansion of studies that apply phylogenetic data and methods to community ecology. Several key areas are reviewed in which phylogenetic information helps to resolve long-standing controversies in community ecology, challenges previous assumptions, and opens new areas of investigation. In particular, studies in phylogenetic community ecology have helped to reveal the multitude of processes driving community assembly and have demonstrated the importance of evolution in the assembly process. Phylogenetic approaches have also increased understanding of the consequences of community interactions for speciation, adaptation and extinction. Finally, phylogenetic community structure and composition holds promise for predicting ecosystem processes and impacts of global change. Major challenges to advancing these areas remain. In particular, determining the extent to which ecologically relevant traits are phylogenetically conserved or convergent, and over what temporal scale, is critical to understanding the causes of community phylogenetic structure and its evolutionary and ecosystem consequences. Harnessing phylogenetic information to understand and forecast changes in diversity and dynamics of communities is a critical step in managing and restoring the Earth's biota in a time of rapid global change. [source] Identification and characterization of ectosymbionts of distinct lineages in Bacteroidales attached to flagellated protists in the gut of termites and a wood-feeding cockroachENVIRONMENTAL MICROBIOLOGY, Issue 1 2006Satoko Noda Summary Bacterial attachments to nearly the entire surface of flagellated protists in the guts of termites and the wood-feeding cockroach Cryptocercus are often observed. Based on the polymerase chain reaction-amplified 16S rRNA gene sequences, we investigated the phylogenetic relationships of the rod-shaped, attached bacteria (ectosymbionts) of several protist species from five host taxa and confirmed their identity by fluorescence in situ hybridizations. These ectosymbionts are affiliated with the order Bacteroidales but formed three distinct lineages, each of which may represent novel bacterial genera. One lineage consisted of the closely related ectosymbionts of two species of the protist genus Devescovina (Cristamonadida). The second lineage comprised three phylotypes identified from the protist Streblomastix sp. (Oxymonadida). The third lineage included ectosymbionts of the three protist genera Hoplonympha, Barbulanympha and Urinympha in the family Hoplonymphidae (Trichonymphida). The ultrastructural observations indicated that these rod-shaped ectosymbionts share morphological similarities of their cell walls and their point of attachment with the protist but differ in shape. Elongated forms of the ectosymbionts appeared in all the three lineages. The protist cells Streblomastix sp. and Hoplonympha sp. display deep furrows and vane-like structures, but these impressive structures are probably evolutionarily convergent because both the host protists and their ectosymbionts are distantly related. [source] Does subtle screening for substance abuse work?ADDICTION, Issue 1 2007A review of the Substance Abuse Subtle Screening Inventory (SASSI) ABSTRACT Aim Through a complex combination of direct (face-valid) and indirect (subtle) subscales, the Substance Abuse Subtle Screening Inventory (SASSI) is purported to detect substance use disorders with a high degree of validity regardless of respondent honesty or motivation. This review evaluates empirical evidence regarding the reliability and validity of this widely used screening instrument. Methods Source documents were 36 peer-reviewed reports yielding data regarding the SASSI's internal consistency, test,retest reliability, psychometric structure, convergent and divergent validity and criterion (predictive) validity. Results The total N of the studies reviewed equaled 22 110. Internal consistency is high for the overall SASSI and for its direct but not its indirect (subtle) subscales, suggesting that the instrument taps a single face-valid construct. SASSI classifications converged with those from other direct screening instruments, and were also correlated with ethnicity, general distress and social deviance. Studies found test,retest reliability lower than that reported in the test manuals. Sensitivity was found to be similar to that for public domain screening instruments, but on specificity the SASSI appears to yield a high rate of false positives. Conclusion No empirical evidence was found for the SASSI's claimed unique advantage in detecting substance use disorders through its indirect (subtle) scales to circumvent respondent denial or dishonesty. Recommendations for screening and for future research with the SASSI are offered. [source] Social Behavior of Larvae of the Neotropical Processionary Weevil Phelypera distigma (Boheman) (Coleoptera: Curculionidae: Hyperinae)ETHOLOGY, Issue 7 2004James T. Costa Socially gregarious behavior among free-living leaf-eating insect larvae occurs mostly among Lepidoptera, Symphyta, and a few Chyrsomelidae (Coleoptera). However, the Neotropical hyperine curculionid Phelypera distigma has also evolved this lifestyle, exhibiting a suite of social behaviors unique among beetles. The larvae are nomadic processionary foragers that punctuate foraging bouts with rosette-shaped resting formations (cycloalexy). Larvae also vibrate or bob their heads rapidly when moving, especially when in contact with conspecifics, and this suggests acoustic or vibrational communication. In this study we used observational and experimental approaches to investigate the basis of processionary, cycloalexic,and head-vibration behavior of this species. Larvae used both trail pheromones and thigmotactic signals to organize themselves into head-to-tail processionary columns. The trail pheromone, produced from the center of the abdomen, remains active for up to 4 h. Processions are not consistently led by particular individuals, but dynamically change over time and often temporarily break into two or more subprocessions. Subprocessions reunite through use of the trail pheromone. We found no evidence that head-bobbing generates attraction through substrate-borne or acoustic signals, but this behavior functions in direct contact to excite group activity. Time-lapse videography used to analyze cycloalexic group formation showed that larvae transition from feeding in a line along the leaf margin to cycloalexic formations on the upper leaf surface via a coordinated back-up movement that brings the posterior tip of their abdomens into contact. We identify three phases of cycloalexic formation: line-up, back-up, and an adjustment phase. Complete assembly can be achieved in as little as 5 s, but often the two phases establishing the basic rosette lasts 5,10 min, while the adjustment phase slowly tightens the group over a period of up to an hour. Collectively these studies present the first documented case of chemical trail marking in a beetle, and provide insight into a remarkable social-behavioral repertoire convergent in key respects with the better-studied social caterpillars and sawflies. [source] The academic environment: the students' perspectiveEUROPEAN JOURNAL OF DENTAL EDUCATION, Issue 2008K. Divaris (nci) Abstract Dental education is regarded as a complex, demanding and often stressful pedagogical procedure. Undergraduates, while enrolled in programmes of 4,6 years duration, are required to attain a unique and diverse collection of competences. Despite the major differences in educational systems, philosophies, methods and resources available worldwide, dental students' views regarding their education appear to be relatively convergent. This paper summarizes dental students' standpoint of their studies, showcases their experiences in different educational settings and discusses the characteristics of a positive academic environment. It is a consensus opinion that the ,students' perspective' should be taken into consideration in all discussions and decisions regarding dental education. Moreover, it is suggested that the set of recommendations proposed can improve students' quality of life and well-being, enhance their total educational experience and positively influence their future careers as oral health physicians. The ,ideal' academic environment may be defined as one that best prepares students for their future professional life and contributes towards their personal development, psychosomatic and social well-being. A number of diverse factors significantly influence the way students perceive and experience their education. These range from ,class size', ,leisure time' and ,assessment procedures' to ,relations with peers and faculty', ,ethical climate' and ,extra-curricular opportunities'. Research has revealed that stress symptoms, including psychological and psychosomatic manifestations, are prevalent among dental students. Apparently some stressors are inherent in dental studies. Nevertheless, suggested strategies and preventive interventions can reduce or eliminate many sources of stress and appropriate support services should be readily available. A key point for the Working Group has been the discrimination between ,teaching' and ,learning'. It is suggested that the educational content should be made available to students through a variety of methods, because individual learning styles and preferences vary considerably. Regardless of the educational philosophy adopted, students should be placed at the centre of the process. Moreover, it is critical that they are encouraged to take responsibility for their own learning. Other improvements suggested include increased formative assessment and self-assessment opportunities, reflective portfolios, collaborative learning, familiarization with and increased implementation of information and communication technology applications, early clinical exposure, greater emphasis on qualitative criteria in clinical education, community placements, and other extracurricular experiences such as international exchanges and awareness of minority and global health issues. The establishment of a global network in dental education is firmly supported but to be effective it will need active student representation and involvement. [source] Innervation of interneurons immunoreactive for VIP by intrinsically bursting pyramidal cells and fast-spiking interneurons in infragranular layers of juvenile rat neocortexEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 1 2002Jochen F. Staiger Abstract Cortical columns contain specific neuronal populations with characteristic sets of connections. This wiring forms the structural basis of dynamic information processing. However, at the single-cell level little is known about specific connectivity patterns. We performed experiments in infragranular layers (V and VI) of rat somatosensory cortex, to clarify further the input patterns of inhibitory interneurons immunoreactive (ir) for vasoactive intestinal polypeptide (VIP). Neurons in acute slices were electrophysiologically characterized using whole-cell recordings and filled with biocytin. This allowed us to determine their firing pattern as regular-spiking, intrinsically bursting and fast-spiking, respectively. Biocytin was revealed histochemically and VIP immunohistochemically. Sections were examined for contacts between the axons of the filled neurons and the VIP-ir targets. Twenty pyramidal cells and five nonpyramidal (inter)neurons were recovered and sufficiently stained for further analysis. Regular-spiking pyramidal cells displayed no axonal boutons in contact with VIP-ir targets. In contrast, intrinsically bursting layer V pyramidal cells showed four putative single contacts with a proximal dendrite of VIP neurons. Fast-spiking interneurons formed contacts with two to six VIP neurons, preferentially at their somata. Single as well as multiple contacts on individual target cells were found. Electron microscopic examinations showed that light-microscopically determined contacts represent sites of synaptic interactions. Our results suggest that, within infragranular local cortical circuits, (i) fast-spiking interneurons are more likely to influence VIP cells than are pyramidal cells and (ii) pyramidal cell input probably needs to be highly convergent to fire VIP target cells. [source] Opposing actions of neuropeptide Y and light on the expression of circadian clock genes in the mouse suprachiasmatic nucleiEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 1 2002Elizabeth S. Maywood Abstract The circadian clockwork of the hypothalamic suprachiasmatic nuclei (SCN) is synchronized by light and by nonphotic cues. The core timing mechanism is cell-autonomous, based on an autoregulatory transcriptional/translational feedback loop of circadian genes and their products. This study investigated the effects of neuropeptide Y (NPY), a potent nonphotic resetting cue, and its interaction with light in regulating clock gene expression in the SCN in vivo. Injection of NPY adjacent to the SCN and transfer to darkness 7 h before scheduled lights out, shifted the circadian activity,rest cycle. Exposure to light for 1 h immediately after NPY infusion blocked this behavioural response. NPY-induced shifts were accompanied by suppression of both mPer1 and mPer2 mRNA in the SCN, assessed 3 h after infusion. mPer mRNAs were not altered 1 h after infusion. Levels of mClock mRNA or mCLOCK immunoreactivity in the SCN were not affected by NPY at either time point. In parallel to the behavioural response, the NPY-induced suppression of mPer genes in the SCN was attenuated when a light pulse was delivered immediately after the infusion. These results identify mPer1 and mPer2 as molecular targets for both photic and nonphotic (NPY-induced) resetting of the clockwork, and support a synthetic model of circadian entrainment based upon convergent up- and downregulation of mPer expression. [source] German lexical personality factors: relations with the HEXACO modelEUROPEAN JOURNAL OF PERSONALITY, Issue 1 2007Michael C. Ashton Abstract We correlated the scales of the HEXACO Personality Inventory (HEXACO-PI) with adjective scale markers of factors previously obtained in indigenous lexical studies of personality structure in the German language. Self-ratings obtained from a sample of 323 German participants showed a pattern of strong convergent and weak discriminant correlations, supporting the content-based interpretation of the German lexical factors in terms of the HEXACO dimensions. Notably, convergent correlations were strong for both the broader and the narrower variants of the Honesty-Humility factor as observed in German lexical studies. Also, convergent correlations for HEXACO Openness to Experience were, as expected, stronger for German adjectives describing a creative and intellectual orientation than for German adjectives describing intellectual ability. Copyright © 2006 John Wiley & Sons, Ltd. [source] The construct validity of three entry level personality inventories used in the UK: cautionary findings from a multiple-inventory investigation,EUROPEAN JOURNAL OF PERSONALITY, Issue S1 2003Neil Anderson This paper reports psychometric analyses into the convergent and divergent validity of three popular entry-level measures of occupational personality in the UK and Continental Europe. A sample of 504 individuals completed all three measures: the British version of the Hogan Personality Inventory (HPI), the Occupational Personality Questionnaire (OPQ Version FS5.2), and the Business Personality Indicator (BPI). In addition, independent ratings of the conceptual loading of primary source scales onto the Five Factor Model (FFM) were obtained (n,=,66). Data were used in a three-stage analytical procedure directed at examining psychometric and construct validity. Results are reported for descriptive statistics (means, standard deviations, Cohen's d), internal consistency reliability (Cronbach's alphas), and exploratory factor analyses. Findings into the construct validity of first-order scales (i.e. primary source scales) and second-order scales (i.e. FFM loadings) are presented in detail, including multitrait,multimethod (MTMM) analyses of convergent and divergent validity. For some scales, the observed variability in our sample suggested significant range restriction/enhancement. It was found that scale reliabilities were generally lower than those typically reported by the test publishers, and that published factor structures for these measures could not be replicated by the authors for this sample of individuals. Further independent construct validity research into occupational personality inventories is encouraged based upon our proposed model of single-, dual-, and multiple-inventory construct validation studies. Practically, our findings suggest that when IWO psychologists or personnel professionals aim to select/screen job applicants for a particular personality trait those who are selected may vary depending on (i) which personality inventory is used, (ii) the actual variability in the applicant sample tested, and (iii) reliability of the scales under consideration. As such, this study sounds a note of caution. Future research is called for to replicate these findings. Copyright © 2003 John Wiley & Sons, Ltd. [source] Past success and convergent thinking in groups: The role of group-focused attributionsEUROPEAN JOURNAL OF SOCIAL PSYCHOLOGY, Issue 4 2004Jack A. Goncalo Past success often causes groups to think narrowly around strategies that have worked in the past, even when environmental change has rendered these strategies ineffective. From a psychological perspective, this research seems to indicate that past success may give rise to convergent thinking in groups. Why might successful groups be prone to convergent thinking? I argue that the relationship between past success and convergent thinking may depend on the attributions that groups generate to explain their shared success. In this paper, I focus on two distinct attributions at the group level: Individual-focused attributions that reflect the idiosyncratic characteristics of individual group members and group-focused attributions that reflect the emergent properties of the group as a whole. I found that group-focused attributions for past success cause groups to generate fewer ideas that are, on average, more convergent. In contrast, individual-focused attributions cause groups to generate more ideas that are on average more divergent. These findings suggest that the experience of success may actually stimulate divergent thinking depending on how a group chooses to explain it. Copyright © 2004 John Wiley & Sons, Ltd. [source] CONTRASTING PLANT PHYSIOLOGICAL ADAPTATION TO CLIMATE IN THE NATIVE AND INTRODUCED RANGE OF HYPERICUM PERFORATUMEVOLUTION, Issue 8 2007John L. Maron How introduced plants, which may be locally adapted to specific climatic conditions in their native range, cope with the new abiotic conditions that they encounter as exotics is not well understood. In particular, it is unclear what role plasticity versus adaptive evolution plays in enabling exotics to persist under new environmental circumstances in the introduced range. We determined the extent to which native and introduced populations of St. John's Wort (Hypericum perforatum) are genetically differentiated with respect to leaf-level morphological and physiological traits that allow plants to tolerate different climatic conditions. In common gardens in Washington and Spain, and in a greenhouse, we examined clinal variation in percent leaf nitrogen and carbon, leaf ,13C values (as an integrative measure of water use efficiency), specific leaf area (SLA), root and shoot biomass, root/shoot ratio, total leaf area, and leaf area ratio (LAR). As well, we determined whether native European H. perforatum experienced directional selection on leaf-level traits in the introduced range and we compared, across gardens, levels of plasticity in these traits. In field gardens in both Washington and Spain, native populations formed latitudinal clines in percent leaf N. In the greenhouse, native populations formed latitudinal clines in root and shoot biomass and total leaf area, and in the Washington garden only, native populations also exhibited latitudinal clines in percent leaf C and leaf ,13C. Traits that failed to show consistent latitudinal clines instead exhibited significant phenotypic plasticity. Introduced St. John's Wort populations also formed significant or marginally significant latitudinal clines in percent leaf N in Washington and Spain, percent leaf C in Washington, and in root biomass and total leaf area in the greenhouse. In the Washington common garden, there was strong directional selection among European populations for higher percent leaf N and leaf ,13C, but no selection on any other measured trait. The presence of convergent, genetically based latitudinal clines between native and introduced H. perforatum, together with previously published molecular data, suggest that native and exotic genotypes have independently adapted to a broad-scale variation in climate that varies with latitude. [source] CONVERGENCE AND THE MULTIDIMENSIONAL NICHEEVOLUTION, Issue 2 2005Luke J. Harmon Abstract Convergent evolution has played an important role in the development of the ecological niche concept. We investigated patterns of convergent and divergent evolution of Caribbean Anolis lizards. These lizards diversified independently on each of the islands of the Greater Antilles, producing the same set of habitat specialists on each island. Using a phylogenetic comparative framework, we examined patterns of morphological convergence in five functionally distinct sets of morphological characters: body size, body shape, head shape, lamella number, and sexual size dimorphism. We find evidence for convergence among members of the habitat specialist types for each of these five datasets. Furthermore, the patterns of convergence differ among at least four of the five datasets; habitat specialists that are similar for one set of characters are often greatly different for another. This suggests that the habitat specialist niches into which these anoles have evolved are multidimensional, involving several distinct and independent aspects of morphology. [source] Patterns and consequences of vertebrate Emx gene duplicationsEVOLUTION AND DEVELOPMENT, Issue 4 2009Elizabeth M. Tank SUMMARY We have cloned and analyzed two Emx genes from the lamprey Petromyzon marinus and our findings provide insight into the patterns and developmental consequences of gene duplications during early vertebrate evolution. The Emx gene family presents an excellent case for addressing these issues as gnathostome vertebrates possess two or three Emx paralogs that are highly pleiotropic, functioning in or being expressed during the development of several vertebrate synapomorphies. Lampreys are the most primitive extant vertebrates and characterization of their development and genomic organization is critical for understanding vertebrate origins. We identified two Emx genes from P. marinus and analyzed their phylogeny and their embryological expression relative to other chordate Emx genes. Our phylogenetic analysis shows that the two lamprey Emx genes group independently from the gnathostome Emx1, Emx2, and Emx3 paralogy groups. Our expression analysis shows that the two lamprey Emx genes are expressed in distinct spatial and temporal patterns that together broadly encompass the combined sites of expression of all gnathostome Emx genes. Our data support a model wherein large-scale regulatory evolution of a single Emx gene occurred after the protochordate/vertebrate divergence, but before the vertebrate radiation. Both the lamprey and gnathostome lineages then underwent independent gene duplications followed by extensive paralog subfunctionalization. Emx subfunctionalization in the telencephalon is remarkably convergent and refines our understanding of lamprey forebrain patterning. We also identify lamprey-specific sites of expression that indicate either neofunctionalization in lampreys or sites-specific nonfunctionalization of all gnathostome Emx genes. Overall, we see only very limited correlation between Emx gene duplications and the acquisition of novel expression domains. [source] Phylogenetic distribution of microRNAs supports the basal position of acoel flatworms and the polyphyly of PlatyhelminthesEVOLUTION AND DEVELOPMENT, Issue 5 2007Lorenzo F. Sempere SUMMARY Phylogenetic analyses based on gene sequences suggest that acoel flatworms are not members of the phylum Platyhelminthes, but instead are the most basal branch of triploblastic bilaterians. Nonetheless, this result has been called into question. An alternative test is to use qualitative molecular markers that should, in principle, exclude the possibility of convergent (homoplastic) evolution in unrelated groups. microRNAs (miRNAs), noncoding regulatory RNA molecules that are under intense stabilizing selection, are a newly discovered set of phylogenetic markers that can resolve such taxonomic disputes. The acoel Childia sp. has recently been shown to possess a subset of the conserved core of miRNAs found across deuterostomes and protostomes, whereas a polyclad flatworm,in addition to this core subset,possesses miRNAs restricted to just protostomes. Here, we examine another acoel, Symsagittifera roscoffensis, and three other platyhelminths. Our results show that the distribution of miRNAs in S. roscoffensis parallels that of Childia. In addition, two of 13 new miRNAs cloned from a triclad flatworm are also found in other lophotrochozoan protostomes, but not in ecdysozoans, deuterostomes, or in basal metazoans including acoels. The limited set of miRNAs found in acoels, intermediate between the even more reduced set in cnidarians and the larger and expanding set in the rest of bilaterians, is compelling evidence for the basal position of acoel flatworms and the polyphyly of Platyhelminthes. [source] Terminal addition, the Cambrian radiation and the Phanerozoic evolution of bilaterian formEVOLUTION AND DEVELOPMENT, Issue 6 2005David K. Jacobs Summary We examine terminal addition, the process of addition of serial elements in a posterior subterminal growth zone during animal development, across modern taxa and fossil material. We argue that terminal addition was the basal condition in Bilateria, and that modification of terminal addition was an important component of the rapid Cambrian evolution of novel bilaterian morphology. We categorize the often-convergent modifications of terminal addition from the presumed ancestral condition. Our focus on terminal addition and its modification highlights trends in the history of animal evolution evident in the fossil record. These trends appear to be the product of departure from the initial terminal addition state, as is evident in evolutionary patterns within-fossil groups such as trilobites, but is also more generally related to shifts in types of morphologic change through the early Phanerozoic. Our argument is contingent on dates of metazoan divergence that are roughly convergent with the first appearance of metazoan fossils in the latest Proterozoic and Cambrian, as well as on an inference of homology of terminal addition across bilaterian Metazoa. [source] | |||||||||||||||||||||||||||||||||||||||||||||||||