From lows to highs: using low-resolution models to phase X-ray data

The study of virus structures has contributed to methodo­logical advances in structural biology that are generally applicable (molecular replacement and noncrystallographic symmetry are just two of the best known examples). Moreover, structural virology has been instrumental in forging the more general concept of exploiting phase information derived from multiple structural techniques. This hybridization of structural methods, primarily electron microscopy (EM) and X-ray crystallography, but also small-angle X-ray scattering (SAXS) and nuclear magnetic resonance (NMR) spectroscopy, is central to integrative structural biology. Here, the interplay of X-ray crystallography and EM is illustrated through the example of the structural determination of the marine lipid-containing bacteriophage PM2. Molecular replacement starting from an ∼13 Å cryo-EM reconstruction, followed by cycling density averaging, phase extension and solvent flattening, gave the X-ray structure of the intact virus at 7 Å resolution This in turn served as a bridge to phase, to 2.5 Å resolution, data from twinned crystals of the major coat protein (P2), ultimately yielding a quasi-atomic model of the particle, which provided significant insights into virus evolution and viral membrane biogenesis

Spatial arrangement of several flagellins within bacterial flagella improves motility in different environments

Bacterial flagella are helical proteinaceous fibers, composed of the protein flagellin, that confer motility to many bacterial species. The genomes of about half of all flagellated species include more than one flagellin gene, for reasons mostly unknown. Here we show that two flagellins (FlaA and FlaB) are spatially arranged in the polar flagellum of Shewanella putrefaciens, with FlaA being more abundant close to the motor and FlaB in the remainder of the flagellar filament. Observations of swimming trajectories and numerical simulations demonstrate that this segmentation improves motility in a range of environmental conditions, compared to mutants with single-flagellin filaments. In particular, it facilitates screw-like motility, which enhances cellular spreading through obstructed environments. Similar mechanisms may apply to other bacterial species and may explain the maintenance of multiple flagellins to form the flagellar filament

A Systematic Review of Data Collection Techniques Used to Measure Preschool Children’s Knowledge of and Preference for Physical Activity

Background: Early childhood has been identified as a crucial period in which children develop physical activity preferences and behaviors. Both the knowledge of and preferences for physical activity are key proximal indicators of activity choices in children. Thus, accurate data collection tools are required to measure these variables. This review evaluates the data collection techniques that have been utilised to assess preschool children’s knowledge of and preference for physical activity, and examines the validity and reliability of existing techniques. Methods: A systematic search for relevant studies published from 1980 through to December 2017 was conducted via ProQuest, CINAHL, Embase, Scopus, ERIC, PubMed, MEDLINE, and ScienceDirect. Results: Fourteen studies were eligible for inclusion in the review. The identified studies employed a limited but disparate range of techniques to assess children’s physical activity knowledge and preferences. Findings reveal that four techniques were consistently used across the reviewed studies, including: interviews, structured play-based activities, questionnaires, and observations. Only four out of 14 included studies reported the assessment of the validity of the data collection tool used, and six reported testing the measures for at least one type of reliability. Conclusion: There is a need for validated and reliable measures to assess children’s knowledge of and preference for physical activity. Greater consideration is required to align data collection techniques with the characteristics, needs and abilities of this study population

Differential influences of social support on app use for diabetes self-management - a mixed methods approach

Background: Recent studies increasingly examine social support for diabetes self-management delivered via mHealth. In contrast to previous studies examining social support as an outcome of technology use, or technology as a means for delivering social support, this paper argues that social support has an impact on the use of diabetes mHealth apps. Specifically, we postulate differences between the impact of healthcare professional versus non-professional (family/friends) support on mobile app use for diabetes self-management. Methods: This research employed a triangulation of methods including exploratory semi-structured face-to-face interviews (N = 21, Study 1) and an online survey (N = 65, Study 2) with adult type 1 and type 2 diabetes patients. Thematic analysis (Study 1) was used to explore the relevance of social support (by professionals versus non-professionals) for diabetes app use. Binary logistic regression (Study 2) was applied to compare healthcare decision-making, healthcare-patient communication, and the support by the personal patient network as predictors of diabetes app use, complemented by other predictors from self-management and technology adoption theory. Results: The interviews (Study 1) demonstrated that (technology-supported) shared decision-making and supportive communication by healthcare professionals depended on their medical specialty. The personal patient network was perceived as either facilitating or hindering the use of mHealth for self-management. Binary logistic regression (Study 2) showed that the physician specialty significantly predicted the use of diabetes apps, with supervision by diabetes specialists increasing the likelihood of app use (as opposed to general practitioners). Additionally, specialist care positively related to a higher chance of shared decision-making and better physician-patient communication. The support by the personal patient network predicted diabetes app use in the opposite direction, with less family/friend support increasing the likelihood of app use. Conclusion: The results emphasize the relevance of support by healthcare professionals and by the patient network for diabetes app use and disclose differences from the existing literature. In particular, the use of diabetes apps may increase in the absence of social support by family or friends (e.g., compensation for lack of support), and may decrease when such support is high (e.g., no perceived need to use technology).Nanyang Technological UniversityPublished versionStudy funding was provided by the Nanyang Technological University (research grant number M4081081)

An Analysis of Power Dynamics Affecting Handwashing Interventions in Sierra Leone: Findings From a Qualitative Participatory Study

Lütke Lanfer H, Brew-Sam N, Rossmann C. An Analysis of Power Dynamics Affecting Handwashing Interventions in Sierra Leone: Findings From a Qualitative Participatory Study. JMIR formative research : electronic, mobile, digital health approaches in cardiology and for cardiovascular health . 2023;7: e39226.BACKGROUND: Handwashing is an effective and cost-efficient health behavior for preventing infectious diseases; however, its practice is shaped by multiple contextual factors and inequalities between different social groups in Sierra Leone. To address these inequalities, participatory approaches that allow a more equitable distribution of resources and the development of locally tailored interventions are increasingly used. However, social power dynamics have not been well integrated into the concept of participation, despite their known impact.; OBJECTIVE: We sought to investigate the role of power dynamics in participatory approaches to handwashing in Sierra Leone.; METHODS: From a socio-ecological perspective, this qualitative, formative interview study aimed to identify relevant actors and their power relationships before designing a participatory handwashing project in rural Sierra Leone. A field experiment with focus groups and a research diary compared the development of power dynamics in a participatory, community-driven approach with that in a nonparticipatory top-down approach.; RESULTS: According to our formative study, in community-based projects, multiple groups and actors interact directly or indirectly with each other, located within a macro level (eg, political institutions), meso level (eg, community leaders and groups), and micro level (eg, families) of a socio-ecological model. Although distinct leadership structures were noticeable and affected intervention attendance and processes of change in nonparticipatory approaches, community-led activities and handwashing increased in the participatory approach, irrespective of the leadership structure. Despite their ambivalence, the strategic inclusion of different community leaders appeared essential to enhance the value of the project, mobilize creative action, and empower lower-ranking individuals to practice handwashing. A similar ambivalent role could be observed in relation to external researchers, especially if they come from a different cultural background than the research participants, for example, from a Western country in a non-Western project setting. Although external researchers can initiate a project or provide certain resources, distinct expectations regarding their roles and resources can impact participatory efforts and power relations.; CONCLUSIONS: The results highlight the advantages of participatory approaches for health promotion. Power dynamics should be a core component of continuous reflection and analysis in participatory projects. ©Hanna Luetke Lanfer, Nicola Brew-Sam, Constanze Rossmann. Originally published in JMIR Formative Research (https://formative.jmir.org), 27.01.2023

Appropriation of mobile health for diabetes self-management : lessons from two qualitative studies

Background: To achieve clarity on mobile health’s (mHealth’s) potential in the diabetes context, it is necessary to understand potential users’ needs and expectations, as well as the factors determining their mHealth use. Recently, a few studies have examined the user perspective in the mHealth context, but their explanatory value is constrained because of their limitation to adoption factors. Objective: This paper uses the mobile phone appropriation model to examine how individuals with type 1 or type 2 diabetes integrate mobile technology into their everyday self-management. The study advances the field beyond mere usage metrics or the simple dichotomy of adoption versus rejection. Methods: Data were gathered in 2 qualitative studies in Singapore and Germany, with 21 and 16 respondents, respectively. Conducting semistructured interviews, we asked respondents about their explicit use of diabetes-related apps, their general use of varied mobile technologies to manage their disease, and their daily practices of self-management. Results: The analysis revealed that although some individuals with diabetes used dedicated diabetes apps, most used tools across the entire mobile-media spectrum, including lifestyle and messaging apps, traditional health information websites and forums. The material indicated general barriers to usage, including financial, technical, and temporal restrictions. Conclusions: In sum, we find that use patterns differ regarding users’ evaluations, expectancies, and appropriation styles, which might explain the inconclusive picture of effects studies in the diabetes mHealth context.Published versio

Permissive hypercapnia for severe acute respiratory distress syndrome in immunocompromised children: A single center experience.

Controlled hypoventilation while accepting hypercapnia has been advocated to reduce ventilator-induced lung injury. The aim of the study was to analyze outcomes of a cohort of immunocompromised children with acute respiratory distress syndrome (ARDS) ventilated with a strategy of stepwise increasing PCO2 targets up to 140 mm Hg.Retrospective analysis of outcomes of a cohort of children with oncologic disease or after stem cell transplantation and severe respiratory failure in comparison with a historical control cohort.Out of 150 episodes of admission to the PICU 88 children underwent invasive mechanical ventilation for >24h (overall survival 75%). In a subgroup of 38 children with high ventilator requirements the PCO2 target ranges were increased stepwise. Fifteen children survived and were discharged from the PICU. Severe pulmonary hypertension was seen in two patients and no case of cerebral edema was observed. Long term outcome was available in 15 patients and 10 of these patients survived without adverse neurological sequelae. With introduction of this strategy survival of immunocompromised children undergoing mechanical ventilation for >24h increased to 48% compared to 32% prior to introduction (historical cohort).A ventilation strategy incorporating very high carbon dioxide levels to allow for low tidal volumes and limited inspiratory pressures is feasible in children. Even severe hypercapnia may be well tolerated. No severe side effects associated with hypercapnia were observed. This strategy could potentially increase survival in immunocompromised children with severe ARDS

Comparison of the recent permissive hypercapnia period with a historical period.

<p>Patients ventilated ≥24h^{<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0179974#t005fn001" target="_blank">*</a>}.</p