Cytotoxicity and effect of extraction methods on the chemical composition of essential oils of Moringa oleifera seeds

Renewed interest in natural materials as food flavors and preservatives has led to the search for suitable essential oils. Moringa oleifera seed essential oil was extracted by solvent-free microwave and hydrodistillation. This study assessed its chemical constituents. Cytotoxicity of the oils was investigated using hatchability and lethality tests on brine shrimps. A total of 16 and 26 compounds were isolated from the hydrodistillation extraction (HDE) and solvent-free microwave extraction (SME) oils, respectively, which accounted for 97.515% and 97.816% of total identifiable constituents, respectively. At 24 h when the most eggs had hatched, values of the SME (56.7%) and HDE (60.0%) oils were significantly different (P<0.05) from those of sea water (63.3%) and chloramphenicol (15.0%). Larva lethality was different significantly (P<0.05) between HDE and SME oils at different concentrations and incubation periods. The median lethal concentration (LC₅₀) of the oils was >1000 mg/ml recommended as an index for non-toxicity, which gives the oil advantage over some antioxidant, antimicrobial, therapeutic, and preservative chemicals.     

Undisclosed Flexibility in Computing and Reporting Structural Equation Models in Communication Science

The use of structural equation modeling (SEM) in communication research has become increasingly popular in recent years, with SEM being commonly used as the primary method of data analysis in studies published within the field’s journals. However, despite its widespread use, there are persistent misapplications of SEM in published empirical studies in the communication sciences. Of these types of misuse, the most troubling are those related to the exploitation of flexibilities in data collection and analysis. Given the number of decisions that must be made when analyzing and reporting structural equation models, decisions which often remain undisclosed, the potential for researchers to exploit flexibilities in SEM research is high. To assess the extent of this problem, as well as the more longstanding types of misuse (i.e., omission of information and disclosed “bad practice”) identified by prior studies, we undertake a methodical review of studies employing structural equation modeling within major journals in the field of communication between the years 2007 and 2011. Articles were coded on the characteristics of the sample, characteristics of the model tested, as well as for various potential problems that we defined a priori. The most serious issues are identified, and recommendations for future standards in SEM research are suggested.     

Preparing a CPT Submission Package

The candidate chooses projects for his or her ability to establish credentials as a performance technologist. The clearer the links between actions and improved performance for the client, the stronger the case each example makes. Candidates will need to show this linkage between contribution and outcome for each project used in preparing the submission package.     

Racial and Gender Identity Among Black Adolescent Males: An Intersectionality Perspective

A considerable amount of social identity research has focused on race and racial identity, while gender identity, particularly among Black adolescents, remains underexamined. The current study used survey data from 183 Black adolescent males (13–16 years old) to investigate the development and relation between racial and gender identity centrality and private regard, and how these identities impact adjustment over time. It was found that dimensions of racial and gender identity were strongly correlated. Levels of racial centrality increased over time while gender centrality, and racial and gender private regard declined. In addition, racial and gender identity uniquely contributed to higher levels of psychological well‐being and academic adjustment. These findings are discussed within the context of existing identity theories and intersectionality theory.     

Thai pre-service science teachers engaging action research during their fifth year internship

As a key element in teacher education programmes, action research is a learning process in which pre-service teachers inquire, reflect on and improve their teaching practices. This qualitative study sought to understand what enhanced or hindered Thai pre-service teachers' action research projects during their student teaching. This study drew upon written reflections, focus-group interviews and observations of seminar sessions. Data analysis was inductive, involving categorical aggregation followed by a search for correspondence and patterns. The results indicated that the pre-service teachers misunderstood action research, and also held a negative attitude toward it, both of which led them to superficial analyses of practice. They struggled with time limitations, data gathering and interpretation strategies. In spite of the struggles they experienced, these pre-service science teachers did learn more about the action research through collaboratively working with cooperating teachers and university supervisors and on-campus seminar discussions held concurrently with the fifth year internship. Recognizing and understanding the reasons and thinking patterns at the root of these teachers' difficulties with learning about action research can form the basis for reflecting on and rethinking the components of science teacher preparation programmes in Thailand.     

SPECIFIC COGNITIVE PREDICTORS OF EARLY MATH PROBLEM SOLVING

Development of early math skill depends on a prerequisite level of cognitive development. Identification of specific cognitive skills that are important for math development may not only inform instructional approaches but also inform assessment approaches to identifying children with specific learning problems in math. This study investigated the specific cognitive correlates of math problem solving across early grade levels (1–4) while controlling for basic calculation skills. As expected, basic calculation skill was a significant predictor of math problem solving across the entire sample. However, the addition of cognitive measures almost doubled the variance explained (R² = .61). Additionally, only select cognitive variables contributed to the prediction of math problem solving, and these variables change in importance as children develop higher‐level math skills. Results are discussed within a developmental model, which emphasizes the increasing importance of abstract code representations required in higher levels of math performance.     

Do We Fear Ageing? A Multidimensional Approach to Ageing Anxiety

Ageing anxiety is the expression of peoples' fear of ageing (Lynch, 2000 Lynch, S. M. (2000). Measurement and prediction of aging anxiety. Research on Aging, 22(5), 533.[Crossref], [Web of Science ®] , [Google Scholar]). Despite greater longevity in the population, there is a lack of research into this aspect of life (Lasher &; Faulkender, 1993 Lasher, K. P., &; Faulkender, P. J. (1993). Measurement of aging anxiety: Development of the Anxiety about Aging Scale. The International Journal of Aging &; Human Development, 37(4), 247–259.[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]). This research explored fears of ageing across four dimensions: Fear of Old People, Physical Appearance, Psychological Concerns, and Fear of Losses. Three hundred and forty eight participants aged 18–88 participated in an online survey. Findings were: (a) men and women have different fears of ageing; (b) greater quality contact is related to less ageing anxiety; (c) poor health is related to greater ageing anxiety, (d) ageism, defined by Nelson (2005 Nelson, T. D. (2005). Ageism: Prejudice against our feared future self. Journal of Social Issues, 61(2), 207–221.[Crossref], [Web of Science ®] , [Google Scholar]) as prejudice toward ageing is positively correlated with ageing anxiety. The implications of these findings are that better quality contact and more positive attitudes toward ageing are associated with less ageing anxiety. As such, possible key target areas in developing appropriate interventions are provided, with hope to prepare adults of all ages for the inevitable—life is a terminal illness, so enjoy while you can.