How Do Trait-Mediated Non-lethal Effects of Predation Affect Population-Level Performance of Mosquitoes?

Non-lethal, trait-mediated effects of predation impact prey behavior and life-history traits. Studying how these effects in turn influence prey demography is crucial to understand prey life-history evolution. Mosquitoes are important vectors that claim several million lives every year worldwide by transmitting a range of pathogens. Several ecological factors affect life-history traits of both larval and adult mosquitoes, creating effects that cascade to population-level consequences. Few studies have comprehensively explored the non-lethal effects of predation and its interactions with resources and competition on larval, adult, and population traits of mosquitoes. Understanding these interactions is important because the effects of predation are hypothesized to rescue prey populations from the effects of density-dependence resulting from larval competition. Aedes aegypti larvae reared at two different larval densities and subjected to three non-lethal predator treatments were monitored for survival, development time, and adult size through the larval stages to adult eclosion, and adult females were monitored for survival and reproduction through their first gonotrophic cycle. Intraspecific competition increased larval development time, yielded small-bodied adults, and reduced fecundity in individuals exposed to predatory chemical cues as larvae. Exposure to cues from a living predator affected both body size and latency to blood feed in females. Analysis of life-table traits revealed significant effects of competition on net reproductive rate (R0) of mosquitoes. The interaction between competition and predator treatments significantly affected the cohort rate of increase (r) and the index of performance (r’). The index of performance, which estimates rate of population change based on the size-fecundity relationship, was significantly and positively correlated with r, but overestimated r slightly. Lack of significant effect of predator treatments and larval density on cohort generation time (Tc) further suggests that the observed effects of treatments on r and r’ were largely a consequence of the effects on R0. Also, the significant effects of treatment combinations on larval development time, adult body size and fecundity were ultimately manifested as effects on life-table traits estimated from adult survival and reproduction

A case for enhancing environmental education programs in schools: Reflecting on primary school students’ knowledge and attitudes

© 2016 Treagust et al. Environmental education in schools is of increasing importance as the world population increases with the subsequent demand on resources and the potential for increased pollution. In an effort to enhance the standing of environmental education in the school curriculum, this study was designed to determine primary students’ knowledge about the environment, their attitudes towards helping the environment and what they actually have done to help the environment. The Year 4 and 5 students in regular and gifted classes in one primary school answered a questionnaire called the Children’s Environmental Attitude and Knowledge Scale (CHEAKS) and several students in both Year levels were interviewed in pairs to elaborate on their responses. In the interviews, students discussed what they had been taught in school in relation to the environment. The findings include (1) Year 4 students had a higher commitment to the environment than Year 5 students; (2) gifted students had more knowledge than regular students; and (3) girls were more verbally committed to the environment than boys. Having knowledge about the environment did not necessarily mean that the student was committed to saving the environment, nor did it mean that the student took action to solve environmental problems. While this study was conducted in one school, the implication is the need for the implementation of a curriculum to help students develop their knowledge and attitudes to take proenvironmental actions

Understanding Acid-Base Concepts: Evaluating the Efficacy of a Senior High School Student-Centred Instructional Program in Indonesia

This study was a mixed quantitative–qualitative research to evaluate the efficacy of a designed student-centred instructional (DSCI) program for teaching about acids and bases. The teaching innovation was designed based on constructivist, hands-on inquiry and context-based approaches and implemented in seven 45-min lessons with a class of 36 grade 11 students (experimental group) from a public senior high school in Indonesia. Another class of 38 students (comparison group) from the same school was instructed using a traditional teacher-centred approach. Data were obtained using a (1) 12-item achievement test on acids and bases that was administered to both groups as a pretest and a posttest, (2) self-evaluation 13-item questionnaire on students’ perceptions of their competence and confidence in carrying out the inquiry activities that was administered to the experimental group and (3) 3-item open-ended questionnaire on students’ perceptions of the instructional process using the DSCI that was administered to the experimental group.The results of the study showed that the teaching innovation was effective in improving students’ understanding of acid–base concepts with significant difference between the two groups on the posttest mean scores. Moreover, the effectiveness of the innovation was supported by an increase in students’ interest in learning science as indicated by their (1) positive perceptions of their engagement and competence in doing inquiry activities, (2) positive perceptions of the learning environment and (3) positive outcome expectations. The findings have implications for chemistry teaching in any institution with similar achieving students as well as for the professional development of teachers

DISTRIBUTION OF SNAKES IN HANTANA RANGE AND PERADENIYA UNIVERSITY PARK

Sri Lanka is blessed with a diverse serpentine fauna, and the island harbours 93 snakespecies in 46 genera and 26 families.Seven major habitat types namely Grasslands, Natural forest patches, Streams and waterways, PinUS plantations, Riverine forests, Agricultural lands, and managed landscape inthe Hantana range and Peradeniya University Park were surveyed for six months fromNovember 2001 to April 2002. Day and night-time survey was carried out to locate snakesand to record their microhabitats. Species identification was done in the field andphotographs of snakes were taken whenever necessary .Twenty snake species (25'1'0 of the total: including six endemics were recorded from theseven sites during the survey. Highest number of species (l6) was recorded from thegrasslands. Agricultural lands, Riverine forests and Natural forest held the second highestnumber of species with nine and eight respectively. The number of species in the grasslandrepresents 30%. of the total number present in the country.Hantana Range and the University land are subjected to severe degradation due to humanactivities. The natural forests have. reduced to a greater extent due to the illegal felling, andthe grasslands and Pinus plantations arc subjected to annual fires. Therefore, the mostsnake species found in the grasslands are heavily threatened Study and planningprograms should be initiated to conserve the diverse habitats types in the area to protectand conserve the diverse snake fauna of the area.

Using metacognitive strategies in teaching to facilitate understanding of light concepts among year 9 students

Background: Enhancing students’ metacognitive abilities will help to facilitate their understanding of science concepts. Purpose: The study was designed to conduct and evaluate the effectiveness of a repertoire of interventions aimed at enhancing secondary school students’ metacognitive capabilities and their achievements in science. Sample: A class of 35 Year 9 students participated in the study. Design and methods: The study involved a pre-post design, conducted by the first author as part of the regular designated science programme in a class taught by him. In order to enhance the students’ metacognitive capabilities, the first author employed clearly stated focused outcomes, engaging them in collaborative group work, reading scientific texts and using concept mapping techniques during classroom instruction. The data to evaluate the effectiveness of the metacognitive interventions were obtained from pre- and post-test results of two metacognitive questionnaires, the Metacognitive Support Questionnaire (MSpQ) and the Metacognitive Strategies Questionnaire (MStQ), and data from interviews. In addition, pre-test and post-test scores were used from a two-tier multiple-choice test on Light.Results: The results showed gains in the MSpQ but not in the MStQ. However, the qualitative data from interviews suggested high metacognitive capabilities amongst the high- and average-achieving students at the end of the study. Students’ gains were also evident from the test scores in the Light test. Conclusion: Although the quantitative data obtained from the Metacognitive Strategies Questionnaire did not show significant gains in the students’ metacognitive strategies, the qualitative data from interviews suggested positive perceptions of students’ metacognitive strategies amongst the high- and average-achieving students. Data from the Metacognitive Support Questionnaire showed that there were significant gains in the students’ perceptions of their metacognitive support implying that the majority of the students perceived that their learning environment was oriented towards the development of their metacognitive capabilities. The effect of the metacognitive interventions on students’ achievement in the Light test resulted in students displaying the correct declarative knowledge, but quite often they lacked the procedural knowledge by failing to explain their answers correctly

TimiRGeN: R/Bioconductor package for time series microRNA-mRNA integration and analysis

Motivation: The analysis of longitudinal datasets and construction of gene regulatory networks (GRNs) provide a valuable means to disentangle the complexity of microRNA (miRNA)-mRNA interactions. However, there are no computational tools that can integrate, conduct functional analysis and generate detailed networks from longitudinal miRNA-mRNA datasets. Results: We present TimiRGeN, an R package that uses time point-based differential expression results to identify miRNA-mRNA interactions influencing signaling pathways of interest. miRNA-mRNA interactions can be visualized in R or exported to PathVisio or Cytoscape. The output can be used for hypothesis generation and directing in vitro or further in silico work such as GRN construction

Consequences of a telomerase-related fitness defect and chromosome substitution technology in yeast synIX strains

We describe the complete synthesis, assembly, debugging, and characterization of a synthetic 404,963 bp chromosome, synIX (synthetic chromosome IX). Combined chromosome construction methods were used to synthesize and integrate its left arm (synIXL) into a strain containing previously described synIXR. We identified and resolved a bug affecting expression of EST3, a crucial gene for telomerase function, producing a synIX strain with near wild-type fitness. To facilitate future synthetic chromosome consolidation and increase flexibility of chromosome transfer between distinct strains, we combined chromoduction, a method to transfer a whole chromosome between two strains, with conditional centromere destabilization to substitute a chromosome of interest for its native counterpart. Both steps of this chromosome substitution method were efficient. We observed that wild-type II tended to co-transfer with synIX and was co-destabilized with wild-type IX, suggesting a potential gene dosage compensation relationship between these chromosomes. </p

Effects of a Mathematics Cognitive Acceleration Program on Student Achievement and Motivation

This paper presents the effects of a cognitive acceleration program in mathematics classes on Tongan students’ achievements, motivation and self-regulation. Cognitive Acceleration in Mathematics Education (CAME) is a program developed at King’s College and implemented worldwide with the aim of improving students’ thinking skills, mathematics performance and attitudes. The first author adapted the program materials to Tongan educational context and provided support to participating teachers for 8 months. This study employed a quasi-experimental design with 219 Year 8 students as the experimental group and 119 Year 8 students as the comparison group. There were a significant differences in the mean scores between the pre-test and post-test of the three instruments that were employed in the study, indicating that learning mathematics under the CAME program had a positive effect on levels of students’ self-regulation, motivation and mathematics achievement. Students also reported changes to the ways they learn mathematics

Single cell and spatial transcriptomic analyses reveal microglia-plasma cell crosstalk in the brain during Trypanosoma brucei infection

Human African trypanosomiasis, or sleeping sickness, is caused by the protozoan parasite Trypanosoma brucei and induces profound reactivity of glial cells and neuroinflammation when the parasites colonise the central nervous system. However, the transcriptional and functional responses of the brain to chronic T. brucei infection remain poorly understood. By integrating single cell and spatial transcriptomics of the mouse brain, we identify that glial responses triggered by infection are readily detected in the proximity to the circumventricular organs, including the lateral and 3rd ventricle. This coincides with the spatial localisation of both slender and stumpy forms of T. brucei. Furthermore, in silico predictions and functional validations led us to identify a previously unknown crosstalk between homeostatic microglia and Cd138+ plasma cells mediated by IL-10 and B cell activating factor (BAFF) signalling. This study provides important insights and resources to improve understanding of the molecular and cellular responses in the brain during infection with African trypanosomes