Gunnar E. Höst

Evolutionary Explanations for Antibiotic Resistance in Daily Press, Online Websites and Biology Textbooks in Sweden

The present study explores the extent and precision of evolutionary explanations for antibiotic resistance in communication directed toward the Swedish public. Bacterial resistance develops through evolutionary mechanisms and knowledge of these helps to explain causes underlying the growing prevalence of resistant strains, as well as important countermeasures to address the problem. A content analysis based on key evolutionary concepts underpinning resistance development was conducted on three different data sources: print newspapers, online websites and biology textbooks. The results revealed that evolutionary mechanisms are seldom included in accounts of antibiotic resistance provided by these sources. One of the included textbooks (n = 6) but none of the newspaper articles (n = 221) or websites (n = 19) covered all six concepts considered in the analysis. A cluster of four concepts regarded as most important for understanding the evolution of resistance development was only included in one news article, one textbook and two websites. Moreover, explanations were seldom supported visually and only two accompanying illustrations were found during the analysis. The results indicated that a large proportion of the Swedish public might never encounter an explanation of antibiotic resistance in evolutionary terms. This could be problematic since increased public awareness and understanding is crucial to counter the issue of bacterial resistance.

Converting human carbonic anhydrase II into a benzoate ester hydrolase through rational redesign

Enzymes capable of benzoate ester hydrolysis have several potential medical and industrial applications. A variant of human carbonic anhydrase II (HCAII) was constructed, by rational design, that is capable of hydrolysing para-nitrophenyl benzoate (pNPBenzo) with an efficiency comparable to some naturally occurring esterases. The design was based on a previously developed strategy [G. Höst, L.G. Mårtensson, B.H. Jonsson, Redesign of human carbonic anhydrase II for increased esterase activity and specificity towards esters with long acyl chains, Biochim. Biophys. Acta 1764 (2006) 1601-1606.], in which docking of a transition state analogue (TSA) to the active site of HCAII was used to predict mutations that would allow the reaction. A triple mutant, V121A/V143A/T200A, was thus constructed and shown to hydrolyze pNPBenzo with k(cat)/K(M)=625 (+/- 38) M(-1) s(-1). It is highly active with other ester substrates as well, and hydrolyzes para-nitrophenyl acetate with k(cat)/K(M)=101,700 (+/- 4800) M(-1) s(-1), which is the highest esterase efficiency so far for any CA variant. A parent mutant (V121A/V143A) has measurable K(M) values for para-nitrophenyl butyrate (pNPB) and valerate (pNPV), but for V121A/V143A/T200A no K(M) could be determined, showing that the additional T200A mutation has caused a decreased substrate binding. However, k(cat)/K(M) is higher with both substrates for the triple mutant, indicating that binding energy has been diverted from substrate binding to transition state stabilization.

A Case-Based Study of Students' Visuohaptic Experiences of Electric Fields around Molecules: Shaping the Development of Virtual Nanoscience Learning Environments

Recent educational research has suggested that immersive multisensory virtual environments offer learners unique and exciting knowledge-building opportunities for the construction of scientific knowledge. This paper delivers a case-based study of students’ immersive interaction with electric fields around molecules in a multisensory visuohaptic virtual environment. The virtual architecture presented here also has conceptual connections to the flourishing quest in contemporary literature for the pressing need to communicate nanoscientific ideas to learners. Five upper secondary school students’ prior conceptual understanding of electric fields and their application of this knowledge to molecular contexts, were probed prior to exposure to the virtual model. Subsequently, four students interacted with the visuohaptic model while performing think-aloud tasks. An inductive and heuristic treatment of videotaped verbal and behavioural data revealed distinct interrelationships between students’ interactive strategies implemented when executing tasks in the virtual system and the nature of their conceptual knowledge deployed. The obtained qualitative case study evidence could serve as an empirical basis for informing the rendering and communication of overarching nanoscale ideas. At the time of composing this paper for publication in the current journal, the research findings of this study have been put into motion in informing a broader project goal of developing educational virtual environments for depicting nanophenomena.

Is it my responsibility or theirs? Risk communication about antibiotic resistance in the Swedish daily press

Antibiotic resistance is an increasing global threat involving many actors, including the general public. We present findings from a content analysis of the coverage of antibiotic resistance in the ...

Combined Enzyme and Substrate Design: Grafting of a Cooperative Two-Histidine Catalytic Motif into a Protein Targeted at the Scissile Bond in a Designed Ester Substrate

A histidine‐based, two‐residue reactive site for the catalysis of hydrolysis of designed sulfonamide‐containing para‐nitrophenyl esters has been engineered into a scaffold protein. A matching substrate was designed to exploit the natural active site of human carbonic anhydrase II (HCAII) for well‐defined binding. In this we took advantage of the high affinity between the active site zinc atom and sulfonamides. The ester substrate was designed to position the scissile bond in close proximity to the His64 residue in the scaffold protein. Three potential sites for grafting the catalytic His–His pair were identified, and the corresponding N62H/H64, F131H/V135H and L198H/P202H mutants were constructed. The most efficient variant, F131H/V135H, has a maximum kcat/KM value of approximately 14 000 M−1 s−1, with a kcat value that is increased by a factor of 3 relative to that of the wild‐type HCAII, and by a factor of over 13 relative to the H64A mutant. The results show that an esterase can be designed in a stepwise way by a combination of substrate design and grafting of a designed catalytic motif into a well‐defined substrate binding site.

An interactive and multi-sensory learning environment for nano education

Swift scientific advances in the area of nanoscience suggest that nanotechnology will play an increasingly important role in our everyday lives. Thus, knowledge of the principles underlying such technologies will inevitably be required to ensure a skilled industrial workforce. In this paper we describe the development of a virtual educational environment that allows for various direct interactive experiences and communication of nanophenomena to pupils and citizens, ranging from desktops to immersive and multi-sensory platforms. At the heart of the architecture is a nanoparticle simulator, which simulates effects such as short-range interaction, flexing of nanotubes and collisions with the solvent. The environment allows the user to interact with the particles to examine their behaviour related to fundamental science concepts.

Improved feature detection over large force ranges using history dependent transfer functions

In this paper we present a history dependent transfer function (HDTF) as a possible approach to enable improved haptic feature detection in high dynamic range (HDR) volume data. The HDTF is a multi-dimensional transfer function that uses the recent force history as a selection criterion to switch between transfer functions, thereby adapting to the explored force range. The HDTF has been evaluated using artificial test data and in a realistic application example, with the HDTF applied to haptic protein-ligand docking. Biochemistry experts performed docking tests, and expressed that the HDTF delivers the expected feedback across a large force magnitude range, conveying both weak attractive and strong repulsive protein-ligand interaction forces. Feature detection tests have been performed with positive results, indicating that the HDTF improves the ability of feature detection in HDR volume data as compared to a static transfer function covering the same range.

Swedish technology teachers’ attitudes to their subject and its teaching

Abstract Background: From previous research among science teachers it is known that teachers’ attitudes to their subjects affect important aspects of their teaching, including their confidence and the amount of time they spend teaching the subject. In contrast, less is known about technology teachers’ attitudes. Purpose: Therefore, the aim of this study is to investigate Swedish technology teachers’ attitudes toward their subject, and how these attitudes may be related to background variables. Sample: Technology teachers in Swedish compulsory schools (n = 1153) responded to a questionnaire about teachers’ attitudes, experiences, and background. Methods: Exploratory factor analysis was used to inwvestigate attitude dimensions of the questionnaire. Groupings of teachers based on attitudes were identified through cluster analysis, and multinomial logistic regression was performed to investigate the role of teachers’ background variables as predictors for cluster belonging. Results: Four attitudinal dimensions were identified in the questionnaire, corresponding to distinct components of attitudes. Three teacher clusters were identified among the respondents characterized by positive, negative, and mixed attitudes toward the subject of technology and its teaching, respectively. The most influential predictors of cluster membership were to be qualified for teaching technology, having participated in in-service-training, teaching at a school with a proper overall teaching plan for the subject of technology and teaching at a school with a defined number of teaching hours for the subject. Conclusions: The results suggest that efforts to increase technology teachers’ qualifications and establishing a fixed number of teaching hours and an overall teaching plan for the subject of technology may yield more positive attitudes among teachers toward technology teaching. In turn, this could improve the status of the subject as well as students’ learning.

Engines of Creationism? Intelligent Design, Machine Metaphors and Visual Rhetoric

Machine metaphors are ubiquitous in the molecular sciences. In addition to their use by scientists, educators and popularizers of science, they have been promoted intensively by the Intelligent Design (ID) movement in arguments for the necessity of a god-like designer to account for the complexities of life at the molecular level. The authors have investigated the visual rhetoric employed in a movie by ID proponents, with particular emphasis on machine metaphors. The authors provide examples and argue that science communicators could reduce the persuasive impact of ID visual rhetoric based on machine metaphors by emphasizing that self-assembly is fundamental to molecular complexes.

Condition-related knowledge among children and adolescents with spina bifida in a Swedish county

Spina bifida is a congenital birth defect, resulting in physical and cognitive dysfunctions. Condition-related knowledge among children and adolescents with spina bifida is essential to facilitate independent management of their condition. The aim was to describe the condition-related knowledge among children and adolescents with spina bifida in a Swedish county. Thirteen persons with spina bifida (10 to 17 years) participated. Condition-related knowledge was assessed (n = 13) using a questionnaire (KOSB) and a semi-structured interview (n = 8). Interview data were analyzed using qualitative content analysis. The participants had well-developed knowledge concerning proper bladder management, but were lacking knowledge of signs of shunt malfunctioning and etiology. Some participants were uninterested in learning about their condition, despite being aware that they lacked knowledge. The findings indicate potential areas that may be included in local educational initiatives. It should be considered that persons with spina bifida may not be motivated to learn more about their condition.