Optimizing search results for human learning goals

While past research has shown that learning outcomes can be influenced by the amount of effort students invest during the learning process, there has been little research into this question for scenarios where people use search engines to learn. In fact, learning-related tasks represent a significant fraction of the time users spend using Web search, so methods for evaluating and optimizing search engines to maximize learning are likely to have broad impact. Thus, we introduce and evaluate a retrieval algorithm designed to maximize educational utility for a vocabulary learning task, in which users learn a set of important keywords for a given topic by reading representative documents on diverse aspects of the topic. Using a crowdsourced pilot study, we compare the learning outcomes of users across four conditions corresponding to rankings that optimize for different levels of keyword density. We find that adding keyword density to the retrieval objective gave significant learning gains on some topics, with higher levels of keyword density generally corresponding to more time spent reading per word, and stronger learning gains per word read. We conclude that our approach to optimizing search ranking for educational utility leads to retrieved document sets that ultimately may result in more efficient learning of important concepts.     

Endophytes from medicinal plants and their potential for producing indole acetic acid,improving seed germination and mitigating oxidative stress

Medicinal plants have been used by marginal communities to treat various ailments. However, the potential of endophytes within these bio-prospective medicinal plants remains unknown. The present study elucidates the endophytic diversity of medicinal plants (Caralluma acutangula, Rhazya stricta, and Moringa peregrina) and the endophyte role in seed growth and oxidative stress. Various organs of medicinal plants yielded ten endophytes, which were identified as Phoma sp. (6 isolates), Alternaria sp. (2), Bipolaris sp. (1), and Cladosporium sp. (1) based on 18S rDNA sequencing and phylogenetic analysis. The culture filtrates (CFs; 25%, 50%, and 100% concentrations) from these endophytes were tested against the growth of normal and dwarf mutant rice lines. Endophytic CF exhibited dose-dependent growth stimulation and suppression effects. CF (100%) of Phoma sp. significantly increased rice seed germination and growth compared to controls and other endophytes. This growth-promoting effect was due to the presence of indole acetic acid in endophytic CF. The gas chromatography/mass spectrometry (GC/MS) analysis showed the highest indole acetic acid content ((54.31±0.21) μmol/L) in Bipolaris sp. In addition, the isolate of Bipolaris sp. exhibited significantly higher radical scavenging and anti-lipid peroxidation activity than the other isolates. Bipolaris sp. and Phoma sp. also exhibited significantly higher flavonoid and phenolic contents. The medicinal plants exhibited the presence of bio-prospective endophytic strains, which could be used for the improvement of crop growth and the mitigation of oxidative stresses.     

Ethnic and Racial Identity in Adolescence: Implications for Psychosocial,Academic, and Health Outcomes

The construction of an ethnic or racial identity is considered an important developmental milestone for youth of color. This review summarizes research on links between ethnic and racial identity (ERI) with psychosocial, academic, and health risk outcomes among ethnic minority adolescents. With notable exceptions, aspects of ERI are generally associated with adaptive outcomes. ERI are generally beneficial for African American adolescents' adjustment across all three domains, whereas the evidence is somewhat mixed for Latino and American Indian youth. There is a dearth of research for academic and health risk outcomes among Asian American and Pacific Islander adolescents. The review concludes with suggestions for future research on ERI among minority youth.     

Feeling Good,Happy, and Proud: A Meta‐Analysis of Positive Ethnic–Racial Affect and Adjustment

One point of intersection in ethnic and racial identity research is the conceptual attention paid to how positively youth feel about their ethnicity or race, or positive ethnic–racial affect. This article reports results of a series of meta‐analyses based on 46 studies of this dimension and psychosocial, academic, and health risk outcomes among ethnic and racial minority youth. The overall pattern of results suggests that positive ethnic–racial affect exhibited small to medium associations (r range = |.11| to |.37|) with depressive symptoms, positive social functioning, self‐esteem, well‐being, internalizing, externalizing, academic achievement, academic attitudes, and health risk outcomes. Implications for theory and research about the role of positive ethnic–racial affect among youth growing up in an increasingly diverse society are discussed.     

Performance monitoring of university research: A perspective from Australia

The purpose of this paper is to report on who creates branding within institutions of higher learning, and what impact branding has on core institutional activities such as student recruitment and fundraising, as well as on socio‐psychological factors such as community respect and national prestige. Eighty‐nine tertiary education experts covering three world regions were surveyed in order to gather information to fulfil the paper’s objectives. The nature and extent of involvement of enrolled students, alumni, higher management, external consultants, civic leaders and the business community were investigated to identify the part each plays, if any, in the development of an institutional brand. Findings indicate that institutions have a tendency to brand from the top down rather than from the bottom up.     

Functional observer based controller for stabilizing Takagi–Sugeno fuzzy systems with time-delays

This paper investigates the construction of a fuzzy functional observer for nonlinear systems with time-delays, and the application of the observer to estimate the state functions of the parallel distributed compensation controller for stabilizing the system. Two types of time-delays are considered: constant and time-varying delays with bounded time derivative. Stability conditions are obtained using Lyapunov–Krasovskii functional approach; and the conditions are transformed into linear matrix inequalities with equality constraints so that observer parameters can be calculated using the solution of these inequalities. Functional observer construction procedures are presented considering both constant and time-varying time-delays. Two examples, including one for obtaining a power system stabilizer for a single machine infinite bus system, are presented to illustrate effectiveness of the proposed design procedures.