Lineage specific recombination rates and microevolution in Listeria monocytogenes

Background: The bacterium Listeria monocytogenes is a saprotroph as well as an opportunistic human foodborne pathogen, which has previously been shown to consist of at least two widespread lineages (termed lineages I and II) and an uncommon lineage (lineage III). While some L. monocytogenes strains show evidence for considerable diversification by homologous recombination, our understanding of the contribution of recombination to L. monocytogenes evolution is still limited. We therefore used STRUCTURE and ClonalFrame, two programs that model the effect of recombination, to make inferences about the population structure and different aspects of the recombination process in L. monocytogenes. Analyses were performed using sequences for seven loci (including the house-keeping genes gap, prs, purM and ribC, the stress response gene sigB, and the virulence genes actA and inlA) for 195 L. monocytogenes isolates. Results: Sequence analyses with ClonalFrame and the Sawyer's test showed that recombination is more prevalent in lineage II than lineage I and is most frequent in two house-keeping genes (ribC and purM) and the two virulence genes (actA and inlA). The relative occurrence of recombination versus point mutation is about six times higher in lineage II than in lineage I, which causes a higher genetic variability in lineage II. Unlike lineage I, lineage II represents a genetically heterogeneous population with a relatively high proportion (30% average) of genetic material imported from external sources. Phylograms, constructed with correcting for recombination, as well as Tajima's D data suggest that both lineages I and II have suffered a population bottleneck. Conclusion: Our study shows that evolutionary lineages within a single bacterial species can differ considerably in the relative contributions of recombination to genetic diversification. Accounting for recombination in phylogenetic studies is critical, and new evolutionary models that account for the possibility of changes in the rate of recombination would be required. While previous studies suggested that only L. monocytogenes lineage I has experienced a recent bottleneck, our analyses clearly show that lineage II experienced a bottleneck at about the same time, which was subsequently obscured by abundant homologous recombination after the lineage II bottleneck. While lineage I and lineage II should be considered separate species from an evolutionary viewpoint, maintaining single species name may be warranted since both lineages cause the same type of human disease

Methodology for Designing a System of Public Passenger Transport in a Functional Region

Transport, as an object of research and design, is directly influenced by other functional components of the territory, it is caused by them, but at the same time it determines them in terms of limitations and development. A comprehensive approach to the design of transport systems involves a wide range of analytical and synthetic activities. Transport and territory are interrelated, while transport is one of the main factors defining the functionality of territorial structures. The development of transport systems brings greater availability of work, services, and leisure activities. The transport solution in the territory must be directed towards the adequate satisfaction of the transport needs, which are characterized by the intensity of the transport relations in the territory, depending on the time and quality of the relocation. The article presents a methodology for the design of regional public passenger transport lines, in accordance with the principles of sustainable mobility, supporting the competitiveness of public passenger transport and the efficient use of resources. The proposed methodology presupposes an already completed and processed analytical phase of the transport planning process and includes the impact of public passenger transport on the external environment. The methodology is applicable under the conditions of designing a completely new transport service system, as well as in the process of reorganizing existing transport systems, including rail and bus transport

Portraits of street corner culture

This study will closely examine youth culture primarily from a street corner site in downtown St. John's Newfoundland. The methods used will follow critical ethnographic traditions utilizing individual interviews, group discussions, informal observation, and participation in the group culture. These tools will be used to draw out the personal and collective stories of young people who congregate at this street corner site. The concept of street corner culture is used to place this study outside the context of any institution and within the milieux of youth. The investigation of youth culture occurs in their space and from their vantage point. The street corner here is a place away from family, school, work and the authority of adults who may shape the interaction of the group. Explored in this context are the dimensions of youth experience within the culture of the group. Extracted from the context are the self-representations of young people which depict their social world. -- The portrait of youth culture developed through the study will identify existing gaps and potential bridges between youth experience, school cultures, and pedagogical practice. It is my hope that in capturing the voices of these young people they may contribute to knowledge about youth and fuel new directions in the process of educational change

OFFERING KNOWLEDGE AS A SERVICE - A TAXONOMY OF KNOWLEDGE-INTENSIVE BUSINESS SERVICES

Servitization describes the transformation of a manufacturer to a customer-centric service and solution provider. Providing customer solutions requires the integration of knowledge from different domains, e.g., engineering, software, and service, and usually also entails that more knowledge-intensive business services (KIBS) become part of the manufacturer’s overall business model. Against this background, this article investigates how manufacturing and software firms leverage knowledge in KIBS and corresponding business models. We developed a taxonomy that systematizes KIBS along the three meta-dimensions of value proposition, value creation, and value capture. The application of our taxonomy to exemplary cases from both industries shows different strategies of knowledge usage across these industries. Our findings can support the development of KIBS and help practitioners to understand different ways of utilizing knowledge as a strategic resource. Implications for research point to the need for better understanding the collaboration of multiple actors from a knowledge-based perspective

Catholicism and Organizational Development: A Case Study on the Communication of Catholic Mission and Identity

Don Martin, Kendra Knight, and Scott Kelley explore the results of the Catholic Identity Mission Assessment survey as it relates to DePaul University. This survey was created by the Association of Catholic Colleges and Universities as a way of gauging how effectively Catholic educational institutions are conveying their Catholic identity to their students and other stakeholders. At DePaul, the investigation examined how well graduating seniors “comprehend and articulate principles from the Catholic intellectual tradition and Catholic social teaching.” Martin, Knight, and Kelley cite specific curricular and cocurricular areas that would help seniors establish this Catholic worldview and point out areas in which the communication of Catholic identity needs to be bolstered. They also explore the challenges of communicating that identity, not least of which is the generational interest and existing generational worldview of millennials and Generation Z and the need to compete with secular educational institutions. The authors explain the survey’s method and results. The survey found that “students’ confidence in their ability to articulate dimensions of the Vincentian mission is greater than their confidence in their ability to communicate dimensions of the Catholic intellectual tradition,” which “suggests a need for organizational development.” The article outlines steps for that

CHARGING OF RAILWAY INFRASTRUCTURE OPERATIONAL CAPACITY LIMITATIONS

Príspevok sa detailne zaoberá spoplatnením obmedzení prevádzkovej kapacity železničnej infraštruktúry. Analyzuje dôvody, rozoberá možnosti a dôvody spoplatnenia alebo nespoplatnenia jednotlivých prípadov obmedzenia prevádzkovej kapacity.This article deals with in detail about the charging of railway infrastructure operational capacity limitations. It analyses the reasons, discusses about possibilities and reasons of charging or non-charging of operational capacity limitations by individual cases

Overview and Reassessment of Noise Budget of Starshade Exoplanet Imaging

High-contrast imaging enabled by a starshade in formation flight with a space telescope can provide a near-term pathway to search for and characterize temperate and small planets of nearby stars. NASA’s Starshade Technology Development Activity to TRL5 (S5) is rapidly maturing the required technologies to the point at which starshades could be integrated into potential future missions. Here we reappraise the noise budget of starshade-enabled exoplanet imaging to incorporate the experimentally demonstrated optical performance of the starshade and its optical edge. Our analyses of stray light sources – including the leakage through micrometeoroid damage and the reflection of bright celestial bodies – indicate that sunlight scattered by the optical edge (i.e., the solar glint) is by far the dominant stray light. With telescope and observation parameter that approximately correspond to Starshade Rendezvous with Roman and HabEx, we find that the dominating noise source would be exozodiacal light for characterizing a temperate and Earth-sized planet around Sun-like and earlier stars and the solar glint for later-type stars. Further reducing the brightness of solar glint by a factor of 10 with a coating would prevent it from becoming the dominant noise for both Roman and HabEx. With an instrument contrast of 10⁻¹⁰, the residual starlight is not a dominant noise; and increasing the contrast level by a factor 10 would not lead to any appreciable change in the expected science performance. If unbiased calibration of the background to the photon-noise limit can be achieved, Starshade Rendezvous with Roman could provide nearly photon-limited spectroscopy of temperate and Earth-sized planets of F, G, and K stars < 4 parsecs away, and HabEx could extend this capability to many more stars < 8 parsecs. Larger rocky planets around stars < 8 parsecs would be within the reach of Roman. To achieve these capabilities, the exozodiacal light may need to be calibrated to a precision better than 2% and the solar glint better than 5%. Our analysis shows that the expected temporal variability of the solar glint is unlikely to hinder the calibration, and the main challenge for background calibration likely comes from the unsmooth spatial distribution of exozodiacal dust in some stars. Taken together, these results validate the optical noise budget and technology milestones adopted by S5 against key science objectives and inform the priorities of future technology developments and science and industry community partnerships

Environmental Comparison of Different Transport Modes

The paper describes the energy consumption and GHG production comparison of three transport modes – road, rail and waterborne. The calculations are done according to the legislation in force – standard EN 16 258:2012 Methodology for calculation and declaration of energy consumption and GHG emissions of transport services (freight and passengers). The results have high informative value because they take into account energy consumption and emissions from primary and secondary consideration. The calculation is done by real fuel consumption values (road and waterborne) and by simulation of energy consumption (railway). The energy and emission coefficients from the standard EN were used for estimating the results according to the well-to-wheels and tank-to-wheels principles

The mental well-being and coping strategies of Canadian adolescents during the COVID-19 pandemic: a qualitative, cross-sectional study

BACKGROUND: Qualitative research is lacking on the mental well-being of adolescents during the COVID-19 pandemic. The aim of this study was to explore the feelings and emotions adolescents experienced during the first wave of the COVID-19 pandemic and the coping strategies they identified and employed to manage those emotions. METHODS: Participants living in Canada aged 13-19 years were recruited through social media platforms and youth-serving organizations. Qualitative data were gathered from 2 open-ended questions included in a youth-informed cross-sectional online survey: What feelings and emotions have you experienced around the pandemic? and What coping strategies have you used during the pandemic? We collected data from June 2020 to September 2020. A summative content analysis was undertaken to analyze survey responses inductively. RESULTS: A total of 1164 open-ended responses from Canadian adolescents (n = 851; mean age 15.6, standard deviation 1.7, yr) were analyzed. We identified 3 major themes within the category of feelings and emotions associated with the pandemic: sociospatial and temporal disconnections, emotional toll of the pandemic and positives amid the pandemic. Within the category of coping strategies used during the pandemic, 2 major themes were identified: connecting online and outdoors, and leisure and health-promoting activities. INTERPRETATION: Although the emotional toll of the first wave of the COVID-19 pandemic is evident, participants in our study adopted various positive coping strategies to mitigate their distress, including physical activity, safe peer interactions and hobbies. The results have important implications for public health policy and practice during pandemic times, emphasizing the importance of accessible mental health resources for those experiencing psychological distress

Prevalent Approaches to Professional Development in State 4-H Programs

High-quality 4-H programming requires effective professional development of educators. Through a mixed-methods study, we explored professional development offered through state 4-H programs. Survey results revealed that both in-person and online delivery modes were used commonly for 4-H staff and adult volunteers; for teen volunteers, in-person delivery was most common. Additionally, most professional development efforts were characterized as episodic, expert-led, and group-based (traditional approaches); the least common approaches were described as ongoing, learner-centered, and group-based (reform-based approaches). Interview data supported survey findings. Traditional approaches to professional development are considered ineffective; thus, the implementation of more reform-based professional development opportunities is recommended