Cellular and molecular aspects of the interaction betwen maize and the anthracnose pathogen Colletotrichum graminicola

Maize anthracnose, caused by the fungus Colletotrichum graminicola, is an economically important species contributing to major yield losses. C. graminicola is a hemibiotroph; initially it invades its host while it is alive, and then it switches to destructive necrotrophic growth and the host is killed. Establishment of compatible interactions by biotrophic pathogens is usually associated with suppression of host defenses and cell death, while necrotrophic pathogens typically secrete phytotoxic compounds and induce cell death. To understand the relationship of hemibiotrophy in C. graminicola to biotrophy and necrotrophy, I compared a compatible and an incompatible interaction, utilizing a non-pathogenic mutant strain that is very similar to the wild type in vitro. I developed an assay to visualize in detail living fungal and host cells during pathogenic and nonpathogenic interactions. My results provided evidence that C. graminicola produces diffusible substances during colonization that predispose nearby living host cells for fungal invasion. My observations further suggested that the mutant is nonpathogenic because it fails to produce these substances. To explore the possibility that the C. graminicola mutant is impaired in the production and/or secretion of one or more secondary metabolites (SM), I characterized the range of SM-associated genes in C. graminicola. C. graminicola has a large and diverse repetoire of these genes, indicating significant capacity for the production of SM. I then characterized the global expression of fungal genes during different developmental phases in both compatible and incompatible interactions. I found that SM-associated genes are expressed during early and late stages of maize infection. Secreted proteins and putative effectors were overrepresented among differentially regulated predicted gene products. There were relatively few differences in expression between the mutant and wild type, suggesting that differences between them may relate to post-transcriptional events. The transcriptional analysis indicated that the mutant was defective very early in biotrophy. This study indicates that biotrophy and necrotrophy coexist in this pathosystem in different cells, and that arrays of differentially regulated and locally expressed genes are involved in maintaining this balance. Understanding the nature of induced susceptibility may lead to new therapeutic targets for management of this damaging disease

Implementation of an effective time-saving two-stage methodology for microstructural characterization of cemented carbides

Linear intercept on scanning electron microscopy micrographs is the most commonly used measurement method to determine carbide grain size and contiguity in WC–Co cemented carbides (hardmetals). However, it involves manual time-consuming measurements and is critically dependent on the quality of the micrographs as well as on the identification and definition of grain boundaries. In this study a two-stage methodology for microstructural characterization of hardmetals is presented. First, a digital semi-automatic image analysis procedure for grain size determination of the carbide phase is presented. It involves an experimental assessment of grain size on processed images corresponding to a series of WC–Co and WC–Ni cemented carbide grades with different microstructural characteristics. Obtained results are then compared to the values obtained by means of the linear intercept technique. A good correlation between the mean grain sizes determined following both measurement techniques was attained. Based on experimental findings, a series of empirical relations were found to correlate grain size distributions obtained following both methods. Second, an empirical relation for estimating carbide contiguity in WC–Co cemented carbides is proposed. This relation considers simultaneously the influence of the binder content and the experimentally determined mean grain size on contiguity. The proposed equation for contiguity estimation is based on extensive data collection from open literature. An excellent agreement was attained between contiguity values estimated from such equation and those obtained using the linear intercept technique. This validates the two-stage procedure as an effective time-saving methodology for microstructural characterization of WC–Co cemented carbides.Peer ReviewedPostprint (author's final draft

Self-Organizing Service Ecosystems: Exploring a New Concept for Service Science

The rapid advancements on digital technologies have positioned digital transformation as a central topic of interest to information systems (IS) researchers. However, our understanding of the nature, extent and dynamics of digital service ecosystems remains limited. This short paper contributes to IS and service science research by introducing the conceptualization of self-organizing service ecosystem as an analytical lens for understanding digital transformative phenomena in service ecosystems. To achieve this, we draw on the most recent narrative of value co-creation from service-dominant logic and on key definitions from the theory of self-organization. This paper also discusses future research directions emphasizing on the role and impact of technology in self-organizing service ecosystems

B-Quest: Experience Your Gift

Birthdays are special events for everybody and for most of people it is an important date in their life, it is the day where they feel honoured and appreciated by their friends, family, acquaintances… The main reason for creating an application dedicated to make from the Birthday event a fun game, is generated after bearing in mind how the tradition of giving presents to honour a birthday person is something important in many people\u27s lives. Another aspect considered during the conception of this application is how fast the world is moving, and how sometimes it could be beneficial to have different options to make from an event something different and special. Under this knowledge it is importantly understood that creating an app is a work that requires significant amounts of time and attention. Something that in a fast pace world like this can be considered a luxury.Nevertheless, the opportunity to offer something different to a specific target of users, who enjoy gaming options, is an interesting and worthwhile challenge to be taken

Distribution and Morphologies of Transverse Aeolian Ridges in ExoMars 2020 Rover Landing Site

We thank the efforts of the guest editor and the reviewers for their suggestions in improving the paper. We acknowledge the Wallenberg Foundation and the Kempe Foundation for supporting our Mars research activities in general. We thank Scott Nowicki for providing us the TES-derived rock abundance global dataset for Mars. We thank NASA, JPL, and University of Arizona for providing HiRISE images and DTMs free of charge. The maps in various figures have been created using ArcGIS version 10.6.1 (http://desktop.arcgis.com/en/arcmap/latest/get-started/setup/arcgis-desktop-quick-start-guide.htm).Peer reviewedPublisher PD

Union formation, within-couple dynamics, and child well-being: a global macrolevel perspective

Studies on global changes in families have greatly increased over the past decade, adopting both a country-specific and, more recently, a cross-national comparative perspective. While most studies are focused on the drivers of global changes in families, little comparative research has explored the implications of family processes for the health and well-being of children. This study aims to fill this gap and launch a new research agenda exploring the intergenerational implications of union-formation and within-couple dynamics for children's health and well-being across low- and middle-income countries (LMICs), both globally, regionally, and by the stage of fertility transition. We do so by adopting a macrolevel perspective and a multi-axis conceptualization of children's outcomes-health at birth, health in later life, and schooling-and leveraging Demographic and Health Survey and World Bank data across 75 LMICs. Our results show that in societies where partnerships are characterized by more equal status between spouses-that is, where the age range between spouses and differences in years of schooling between partners are narrower-children fare better on several outcomes. These associations are particularly strong in mid- and high-fertility settings. Despite a series of regularities, our results also highlight a set of findings whereby, at a macrolevel, the prevalence of marriage and divorce/separation are not invariably associated with children's outcomes, especially in LMICs where fertility is comparatively lower. We document little cross-regional heterogeneity, primarily highlighting the centrality of demographic factors such as age vis-à-vis, for instance, region-specific characteristics that are more tied to the social fabric of specific societies

Family Change and Variation Through the Lens of Family Configurations in Low- and Middle-Income Countries

Using 254 Demographic and Health Surveys from 75 low- and middle-income countries, this study shows how the joint examination of family characteristics across rural and urban areas provides new insights for understanding global family change. We operationalize this approach by building family configurations: a set of interrelated features that describe different patterns of family formation and structure. These features include partnership (marriage/unions) regimes and their stability, gender relations, household composition, and reproduction. Factorial and clustering techniques allow us to summarize these family features into three factorial axes and six discrete family configurations. We provide an in-depth description of these configurations, their spatial distribution, and their changes over time. Global family change is uneven because it emerges from complex interplays between the relative steadiness of longstanding arrangements for forming families and organizing gender relations, and the rapidly changing dynamics observed in the realms of fertility, contraception, and timing of family formation