An Analysis of Science Teachers’ Perceptions of Graphical Literacy within the Context of the Secondary Science Classroom

The topic of graphical literacy is considered to be an important aspect of a student’s science education. Skills related to the construction and interpretation of graphs are well documented in science education literature as well as instructional strategies meant to help develop a student’s graphical literacy in science. Absent in the literature is how science teachers address skills related to graphical literacy with their students. The purpose of this study is to provide some insight into how secondary science teachers devote instruction to address graphical literacy with their students in the context of their classroom. Eight secondary science teachers from two school districts in a Midwestern city completed a pre interview survey and then participated in a semi-structured interview. The quantitative and qualitative instruments used in this study asked participants to respond to survey statements and open-ended interview questions related to their instruction of graphing skills within the context of their classroom. Participants also responded to open-ended questions about how they addressed their students’ deficiencies with graphing and instructional strategies used to address those deficiencies. The results of this study demonstrate that the participants were familiar with specific graphing skills and various instructional strategies to address graphing skills identified in the literature. The results further demonstrate that the secondary science teachers who participated in this study addressed graphical literacy in ways that helped their students learn content, promoted graphical literacy as a life-skill, and allowed students opportunities to make connections between math and science

Influence of clay minerals and associated minerals in alkali activation of soils

Alkali activation is promising for low environmental impact soil stabilisation. Given soils’ complexity, there is a lack of fundamental understanding of how the different components in soil influence their alkali activation behaviour. A novel method was developed to compare three natural soils with synthetic versions. Precursors and products were characterised by XRD, SEM, TGA and FTIR to explore the soils’ alkali activation phase formation behaviour. It is shown that only the clay minerals will determine phase formation, whereas most associated minerals had negligible influence. The trade-off between Na:Al and NaOH concentration in mix design means lower plasticity soils are more suitable

Real soils versus fake soils: Does something other than clay minerals influence geopolymerisation behavior in real soils?

Uncalcined geopolymer-stabilised soils have shown potential for replacing concrete and fired clay as low carbon masonry materials. There is now a good fundamental understanding of how aluminosilicate precursors react to form geopolymer phases in simple systems, but there is a knowledge gap for the more complex systems of real soils where minor phases may influence behaviour. Because the clay minerals and their proportions differ between soils, as well as minor phases present, we are still not able to easily predict which soils are suitable for geopolymer stabilisation. In this study, a comparison was made for the alkali activation of real and ‘fake’ soils. Three soils from around the world (UK, India, Sudan) of known mineralogical composition were used. From the real soils’ known mineralogical compositions, ‘artificial soils’ corresponding to each one were made. These were made by mixing refined clays in the same proportions, and using quartz sand as a substitute for all other non-clay phases. The soils were mixed with sodium hydroxide activator and cured. The phases formed were characterised using XRD, FTIR and SEM. From the elemental compositions, the most significant difference was the quantities of iron and calcium present in minor phases. The phases and proportions formed by the alkali activation of each real soil broadly match those formed by the fake soils. The implication for the development of geopolymer-stabilised soil materials is that for a fixed activating solution, minor phases have limited influence on the geopolymer reaction. Nevertheless, the complexity of reaction with mixed soils makes it difficult to predict reaction phases and therefore final products

Solar wind data assimilation in an operational context: use of near‐real‐time data and the forecast value of an L5 monitor

For accurate and timely space weather forecasting, advanced knowledge of the ambient solar wind is required, both for its direct impact on the magnetosphere and for accurately forecasting the propagation of coronal mass ejections to Earth. Data assimilation (DA) combines model output and observations to form an optimum estimation of reality. Initial experiments with assimilation of in situ solar wind speed observations suggest the potential for significant improvement in the forecast skill of near-Earth solar wind conditions. However, these experiments have assimilated science-quality observations, rather than near-real-time (NRT) data that would be available to an operational forecast scheme. Here, we assimilate both NRT and science observations from the Solar Terrestrial Relations Observatory (STEREO) and near-Earth observations from the Advanced Composition Explorer and Deep Space Climate Observatory spacecraft. We show that solar wind speed forecasts using NRT data are comparable to those based on science-level data. This suggests that an operational solar wind DA scheme would provide significant forecast improvement, with reduction in the mean absolute error of solar wind speed around 46% over forecasts without DA. With a proposed space weather monitor planned for the L5 Lagrange point, we also quantify the solar wind forecast gain expected from L5 observations alongside existing observations from L1. This is achieved using configurations of the STEREO and L1 spacecraft. There is a 15% improvement for forecast lead times of less than 5 days when observations from L5 are assimilated alongside those from L1, compared to assimilation of L1 observations alone

Co-evolution of genomes and plasmids within Chlamydia trachomatis and the emergence in Sweden of a new variant strain.

BACKGROUND: Chlamydia trachomatis is the most common cause of sexually transmitted infections globally and the leading cause of preventable blindness in the developing world. There are two biovariants of C. trachomatis: 'trachoma', causing ocular and genital tract infections, and the invasive 'lymphogranuloma venereum' strains. Recently, a new variant of the genital tract C. trachomatis emerged in Sweden. This variant escaped routine diagnostic tests because it carries a plasmid with a deletion. Failure to detect this strain has meant it has spread rapidly across the country provoking a worldwide alert. In addition to being a key diagnostic target, the plasmid has been linked to chlamydial virulence. Analysis of chlamydial plasmids and their cognate chromosomes was undertaken to provide insights into the evolutionary relationship between chromosome and plasmid. This is essential knowledge if the plasmid is to be continued to be relied on as a key diagnostic marker, and for an understanding of the evolution of Chlamydia trachomatis. RESULTS: The genomes of two new C. trachomatis strains were sequenced, together with plasmids from six C. trachomatis isolates, including the new variant strain from Sweden. The plasmid from the new Swedish variant has a 377 bp deletion in the first predicted coding sequence, abolishing the site used for PCR detection, resulting in negative diagnosis. In addition, the variant plasmid has a 44 bp duplication downstream of the deletion. The region containing the second predicted coding sequence is the most highly conserved region of the plasmids investigated. Phylogenetic analysis of the plasmids and chromosomes are fully congruent. Moreover this analysis also shows that ocular and genital strains diverged from a common C. trachomatis progenitor. CONCLUSION: The evolutionary pathways of the chlamydial genome and plasmid imply that inheritance of the plasmid is tightly linked with its cognate chromosome. These data suggest that the plasmid is not a highly mobile genetic element and does not transfer readily between isolates. Comparative analysis of the plasmid sequences has revealed the most conserved regions that should be used to design future plasmid based nucleic acid amplification tests, to avoid diagnostic failures

Specific Receptor Usage in Plasmodium falciparum Cytoadherence Is Associated with Disease Outcome

Our understanding of the basis of severe disease in malaria is incomplete. It is clear that pathology is in part related to the pro-inflammatory nature of the host response but a number of other factors are also thought to be involved, including the interaction between infected erythrocytes and endothelium. This is a complex system involving several host receptors and a major parasite-derived variant antigen (PfEMP1) expressed on the surface of the infected erythrocyte membrane. Previous studies have suggested a role for ICAM-1 in the pathology of cerebral malaria, although these have been inconclusive. In this study we have examined the cytoadherence patterns of 101 patient isolates from varying clinical syndromes to CD36 and ICAM-1, and have used variant ICAM-1 proteins to further characterise this adhesive phenotype. Our results show that increased binding to CD36 is associated with uncomplicated malaria while ICAM-1 adhesion is raised in parasites from cerebral malaria cases

Foraging for foundations in decision neuroscience: insights from ethology

Modern decision neuroscience offers a powerful and broad account of human behaviour using computational techniques that link psychological and neuroscientific approaches to the ways that individuals can generate near-optimal choices in complex controlled environments. However, until recently, relatively little attention has been paid to the extent to which the structure of experimental environments relates to natural scenarios, and the survival problems that individuals have evolved to solve. This situation not only risks leaving decision-theoretic accounts ungrounded but also makes various aspects of the solutions, such as hard-wired or Pavlovian policies, difficult to interpret in the natural world. Here, we suggest importing concepts, paradigms and approaches from the fields of ethology and behavioural ecology, which concentrate on the contextual and functional correlates of decisions made about foraging and escape and address these lacunae

Class, Youth and Dirty Jobs: The Working-Class and Post-War Britain in Pete Townshend's Quadrophenia

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