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El género Dictyota posee aproximadamente 78 especies descritas, distribuidas en una gran variedad de ambientes templad os, subtropicales y tropicales. Como en la mayoría de las algas, la sistemática de Dictyota se ha construido principalmente bajo el enfoque del concepto morfológico de especie. Sin embargo, la alta plasticidad fenotípica que acompaña a las especies que con forman a este género, por un lado, dificulta el reconocimiento de características diagnósticas, por la sobreposición de caracteres, generando así la asignación de epítetos erróneos cuando se realiza el trabajo de identificación. Y por el otro, se hacen evidentes o se reconocen las especies cripticas. En México se han registrado 12 especies en el Atlántico mexicano. Cabe mencionar que estas especies se han determinado con trabajos que compilan solo registros o con obras en las cuales solo se realiza una breve descripción morfológica. En el presente trabajo se realizaron recolectas de especímenes de Dictyota en la zona intermareal, las cuales fueron hechas en 9 localidades del estado de Veracruz y 6 localidades del estado de Quintana Roo. Se obtuvieron 33 secuencias del gen psb A y 20 para el gen cox 1, las cuales fueron incluidas en el análisis de filogenia molecular junto con secuencias de Dictyota procedentes del GenBank. Como resultado de estos análisis se evidenció la presencia de 12 entidades taxonómicas, complementadas con análisis morfológicos, de las cuales, seis tienen correspondencia con nombres válidos (Canistrocarpuscervicornis, D.ciliolata , D. guineensis, D. jamaicensis D. mertensii y D. pinnatifida ) . Se reporta a D. canariensis como un nuevo regist ro para el A tlántico mexicano. S e describen 3 nuevas especies: D. mayae, D. pedrochei y D. chalchi uh cueyecanensis . Además, se reportan dos nuevas entidades taxonómicas: Dictyota sp. 2 y Dictyota sp. 3, quedando pendiente su circunscripción. Del presente estudio se derivaron los primeros resultados que aborda n a l género Dictyota en el Atlántico mexicano con la intención de contribuir a la comprensión y conocimiento de su filogenia con evidencias molecular es y morfológicas. Dictyota owns approximately 78 described species, distributed in a wide range of temperate, subtropical and tropical environments. As in most of the algae, the systematic of Dictyota is constructed mainly from the standpoint of morphological species concept. However, high phenotypic plasticity accompanying species that conform to this genus, difficult to recognize characteristics diagnostic for overlaying of characters, generating erroneous allocation epithets when the identification work is performed. In Mexico there have been 12 species in the Mexican Atlantic. It is noteworthy that these species have been determined on ly in compiling records or works in which only a brief morphological description is made. In this paper collecting Dictyota specimens were conducted in the intertidal zone, which were made in 9 localities in the state of Veracruz and 6 localities in the state of Quintana Roo. 33 psb A gene sequences and 20 for cox 1 gene were obtained, which were included in the analysis of molec ular phylogeny together with Dictyota sequences from GenBank. As a result of these analyzes the presence of 12 taxa was evident, complemented by morphological analysis, of which six have correspondence with valid names (Canistrocarpus cervicorni s, D. cilio lata, D. guineensis , D. jamaicensis , D. mertensii and D. pinnatifida ). D. canariensis is reported as a new record for the Mexican Atlantic. 3 new species are described. D. mayae , D. pedrochei and D. chalchi uh cueyecanensis . In addition two new taxa are repo rted: Dictyota sp.2 and Dictyota sp.3, pending their circumscription. From this study we have the first results that adress to Dictyota genus in the Mexican Atlantic with the intention of contributing to the understanding and knowledge of their phylogeny w ith molecular and morphological evidence.

Objectives We conducted two studies to examine the dimensions, internal consistency reliability estimates, and potential correlates of the Depression Anxiety Stress Scales—21 (DASS-21; Lovibond & Lovibond, 1995). Method Participants in Study 1 included 887 undergraduate students (363 men and 524 women, aged 18 to 35 years; mean [M] age = 19.46, standard deviation [SD] = 2.17) recruited from two public universities to assess the specificity of the individual DASS-21 items and to evaluate estimates of internal consistency reliability. Participants in a follow-up study (Study 2) included 410 students (168 men and 242 women, aged 18 to 47 years; M age = 19.65, SD = 2.88) recruited from the same universities to further assess factorial validity and to evaluate potential correlates of the original DASS-21 total and scale scores. Results Item bifactor and confirmatory factor analyses revealed that a general factor accounted for the greatest proportion of common variance in the DASS-21 item scores (Study 1). In Study 2, the fit statistics showed good fit for the bifactor model. In addition, the DASS-21 total scale score correlated more highly with scores on a measure of mixed depression and anxiety than with scores on the proposed specific scales of depression or anxiety. Coefficient omega estimates for the DASS-21 scale scores were good. Conclusions Further investigations of the bifactor structure and psychometric properties of the DASS-21, specifically its incremental and discriminant validity, using known clinical groups are needed.

SUMMARY For many students concepts like fluid and crystallized intelligence are difficult to learn because they have highly-similar definitions that are easy to confuse. The challenge of learning these highlysimilar, yet often confused concepts is further complicated by the fact that students are tested on exams about differences between the concepts. In this theoretically-motivated research we test a new strategy for learning highly-similar pairs of concepts, called differential-associative processing. The results revealed that performance on multiple-choice questions was higher when students learned highly-similar concepts using differential-associative processing rather than a strategy of their own choice, text-based elaboration, or identifying similarities and differences. The results also revealed that students spontaneously transferred differential-associative processing to a neutral control condition. Taken as a whole, the present study supports differential-associative processing as a useful strategy for learning similar concepts. Copyright # 2009 John Wiley & Sons, Ltd.

We investigated the factor structure, reliability estimates, and correlates of the Anxiety Sensitivity Index-3 (ASI-3; Taylor et al., 2007) in 2 studies. We established a bifactor model in Study 1 as an alternative representation of the structure of the ASI-3. Analyses of gender differences on the total ASI-3 and subscale scores were not statistically significant (Study 1, N = 462). In Study 2 (N = 293), results of a series of confirmatory factor analyses provided stronger support for the fit of the bifactor model compared with 2 alternative models. Estimates of scale reliability were adequate (all rho values > or = .80) and not "p" (as in italic p for significance). in the 2 studies. In addition, using simultaneous regression analyses, we found anxiety-specific correlates for the total ASI-3 and subscale scores to include responses on self-report measures of interpersonal sensitivity, obsessive-compulsive anxiety, paranoid ideation, and phobic anxiety.

We conducted two studies to examine the dimensions, internal consistency reliability estimates, and potential correlates of the Depression Anxiety Stress Scales-21 (DASS-21; LovibondLovibond, 1995).Participants in Study 1 included 887 undergraduate students (363 men and 524 women, aged 18 to 35 years; mean [M] age = 19.46, standard deviation [SD] = 2.17) recruited from two public universities to assess the specificity of the individual DASS-21 items and to evaluate estimates of internal consistency reliability. Participants in a follow-up study (Study 2) included 410 students (168 men and 242 women, aged 18 to 47 years; M age = 19.65, SD = 2.88) recruited from the same universities to further assess factorial validity and to evaluate potential correlates of the original DASS-21 total and scale scores.Item bifactor and confirmatory factor analyses revealed that a general factor accounted for the greatest proportion of common variance in the DASS-21 item scores (Study 1). In Study 2, the fit statistics showed good fit for the bifactor model. In addition, the DASS-21 total scale score correlated more highly with scores on a measure of mixed depression and anxiety than with scores on the proposed specific scales of depression or anxiety. Coefficient omega estimates for the DASS-21 scale scores were good.Further investigations of the bifactor structure and psychometric properties of the DASS-21, specifically its incremental and discriminant validity, using known clinical groups are needed.

The authors conducted three studies to construct and examine the psychometric properties of a 27-item version of the Mood and Anxiety Symptom Questionnaire-90 (MASQ-90; Watson & Clark, 1991a). The Anxiety Depression Distress Inventory-27 (ADDI-27) contains three empirically derived scales: Positive Affect, Somatic Anxiety, and General Distress, which are relevant dimensions of the tripartite model of affect. Each scale is composed of nine items, and the estimate of scale reliability for each scale score was ≥ .80 across the three studies. Results of exploratory and confirmatory factor analyses provided adequate support for a 3-factor model. Additional estimates of concurrent validity documented the ADDI-27 scales' convergent and discriminant validity. We also identified three construct relevant correlates for each scale score. Overall, the ADDI-27 appears to be a content valid, reliable, and multidimensional measure of the tripartite model of affect.

We describe the development and initial psychometric properties of a 24-item self-report measure, the University of Texas at San Antonio Future Disposition Inventory (UTSA FDI). This instrument is designed to evaluate future related thoughts and feelings that are associated with suicide-related risk behaviors: positive focus, suicide orientation, and negative focus. The items were generated by clinical and nonclinical samples. The structure of the instrument was defined in a sample of 350 university undergraduate students (Study 1). Using CFA, we confirmed the fit of the 3-factor solution in an independent sample of college age students (n=452; Study 2). Scale reliability estimates were good (all rho's>or=.80) in both studies. Known-groups validation analyses showed that scores on each scale were useful in differentiating the responses of the study groups. Correlates for the scales were identified when scores on measures of suicide-related risk and general psychological symptoms were included as validation self-report instruments.