The relative importance of competition and predation in environment characterized by resource pulses - an experimental test with a microbial community

Peer reviewe

Self-Organising Map Approach to Individual Profiles: Age, Sex and Culture in Internet Dating

A marked feature of recent developments in the networked society has been the growth in the number of people making use of Internet dating services. These services involve the accumulation of large amounts of personal information which individuals utilise to find others and potentially arrange offline meetings. The consequent data represent a challenge to conventional analysis, for example, the service that provided the data used in this paper had approximately 5,000 users all of whom completed an extensive questionnaire resulting in some 300 parameters. This creates an opportunity to apply innovative analytical techniques that may provide new sociological insights into complex data. In this paper we utilise the self-organising map (SOM), an unsupervised neural network methodology, to explore Internet dating data. The resulting visual maps are used to demonstrate the ability of SOMs to reveal interrelated parameters. The SOM process led to the emergence of correlations that were obscured in the original data and pointed to the role of what we call \'cultural age\' in the profiles and partnership preferences of the individuals. Our results suggest that the SOM approach offers a well established methodology that can be easily applied to complex sociological data sets. The SOM outcomes are discussed in relation to other research about identifying others and forming relationships in a network society.Self-Organising Map; Neural Network; Complex Data; Internet Dating; Age; Sex; Culture; Relationship; Visualisation

Analyzing science teachers’ support of dialogic argumentation using teacher roles of questioning and communicative approaches

The purpose of this study is to investigate how teachers use different types of discourse to support dialogic argumentation. Dialogic argumentation is a collaborative process in which students construct arguments together and examine arguments presented by their peers. Science teachers can use argumentation as a vehicle to help students gain a working understanding of science content and the nature of science and its practices. Whole-class closing discussions from video-recorded lessons are analyzed to study the discourse used to support argumentation by two physics teachers in lower secondary schools. Analysis of discourse includes coding of communicative approach at the episode level and coding of teacher roles of questioning at the level of speaking turns. Student argumentation is also assessed on the basis of dialogicity and complexity of arguments. Findings characterize different ways of orchestrating argumentative discussions. Authoritative episodes were characterized by the presence of the dispenser role, with teachers retaining ownership over ideas and classroom activities to emphasize the correctness of a justification. Dialogic episodes of classroom interaction showed openness to student perspectives, but teachers’ use of questioning roles revealed different ways of orchestrating argumentative discussions. The moderator role granted ownership of ideas to students to either pursue a single student’s argument in more depth or to directly contrast opposing justifications. Less commonly used were the roles of coach and participant, which teachers used to elicit student justifications in more depth or support students in examining the arguments of their peers. Examination of discourse using multiple frameworks revealed differences in teachers’ values and the impact of the use of teacher questioning roles on student contributions to argumentative discussions

Svalbard reindeer winter diets: Long-term dietary shifts to graminoids in response to a changing climate

Arctic ecosystems are changing dramatically with warmer and wetter conditions resulting in complex interactions between herbivores and their forage. We investigated how Svalbard reindeer (Rangifer tarandus platyrhynchus) modify their late winter diets in response to long-term trends and interannual variation in forage availability and accessibility. By reconstructing their diets and foraging niches over a 17-year period (1995–2012) using serum δ13C and δ15N values, we found strong support for a temporal increase in the proportions of graminoids in the diets with a concurrent decline in the contributions of mosses. This dietary shift corresponds with graminoid abundance increases in the region and was associated with increases in population density, warmer summer temperatures and more frequent rain-on-snow (ROS) in winter. In addition, the variance in isotopic niche positions, breadths, and overlaps also supported a temporal shift in the foraging niche and a dietary response to extreme ROS events. Our long-term study highlights the mechanisms by which winter and summer climate changes cascade through vegetation shifts and herbivore population dynamics to alter the foraging niche of Svalbard reindeer. Although it has been anticipated that climate changes in the Svalbard region of the Arctic would be detrimental to this unique ungulate, our study suggests that environmental change is in a phase where conditions are improving for this subspecies at the northernmost edge of the Rangifer distribution

Soil bacterial community in potato tuberosphere following repeated applications of a common scab suppressive antagonist

Disease suppressive soils are important for managing soil-borne diseases that cannot be controlled with chemicals. One such disease is the potato common scab caused by Streptomyces species. Suppressiveness against common scab can develop spontaneously in fields where potato is grown for years without interruption, and this has been attributed to non-pathogenic Streptomyces strains. Streptomyces spp. have been used as inoculants in biological control, but their long-term effects have gained less attention. In our previous studies, a nonpathogenic Streptomyces strain (Str272) isolated from a potato common scab lesion suppressed common scab in field trials lasting over 5 years. In this study, bacterial communities in the tuberosphere i.e. in the soil adjacent to potato tubers, were analysed by next generation sequencing (NGS). The aim was to compare bacterial communities in untreated control plots to those in which seed tubers were treated with Str272 in one or several growing seasons. Str272 applications increased soil bacterial diversity and affected the bacterial composition in the potato tuberosphere. The most pronounced differences were observed between the untreated control and the treatments in which the antagonist had been applied in three or four consecutive years. The differences remained similar until the following growing season. Bacterial composition after repeated antagonist applications was associated with lower common scab severity. The antagonist applications had no or only slight effect on the number or abundance of OTUs belonging to Actinobacteria or Streptomyces, and no differences in quantities of pathogenic Streptomyces populations were detected by qPCR. This indicates that suppression of common scab by Str272 may not be based on direct effect on the common scab pathogens but is more likely to be associated with the alterations of the soil bacterial community. The most abundant bacteria phyla in the potato tuberosphere were Actinobacteria, Proteobacteria and Acidobacteria. However, the OTUs responding greatest to the antagonist treatments belonged to Bacterioidetes and Gemmatimonadetes. Results indicate that repeated applications of Str272 can change the bacterial community in the potato tuberosphere and lead to development of soil that is suppressive against potato common scab for several growing seasons after the last application.Peer reviewe

Protist predation can select for bacteria with lowered susceptibility to infection by lytic phages

Background: Consumer-resource interactions constitute one of the most common types of interspecific antagonistic interaction. In natural communities, complex species interactions are likely to affect the outcomes of reciprocal co-evolution between consumers and their resource species. Individuals face multiple enemies simultaneously, and consequently they need to adapt to several different types of enemy pressures. In this study, we assessed how protist predation affects the susceptibility of bacterial populations to infection by viral parasites, and whether there is an associated cost of defence on the competitive ability of the bacteria. As a study system we used Serratia marcescens and its lytic bacteriophage, along with two bacteriovorous protists with distinct feeding modes: Tetrahymena thermophila (particle feeder) and Acanthamoeba castellanii (surface feeder). The results were further confirmed with another study system with Pseudomonas and Tetrahymena thermophila. Results: We found that selection by protist predators lowered the susceptibility to infections by lytic phages in Serratia and Pseudomonas. In Serratia, concurrent selection by phages and protists led to lowered susceptibility to phage infections and this effect was independent from whether the bacteria shared a co-evolutionary history with the phage population or not. Bacteria that had evolved with phages were overall more susceptible to phage infection (compared to bacteria with history with multiple enemies) but they were less vulnerable to the phages they had co-evolved with than ancestral phages. Selection by bacterial enemies was costly in general and was seen as a lowered fitness in absence of phages, measured as a biomass yield. Conclusions: Our results show the significance of multiple species interactions on pairwise consumer-resource interaction, and suggest potential overlap in defending against predatory and parasitic enemies in microbial consumer-resource communities. Ultimately, our results could have larger scale effects on eco-evolutionary community dynamics.Peer reviewe

Airway management in out-of-hospital cardiac arrest in Finland : current practices and outcomes

Background: Though airway management methods during out-of-hospital cardiac arrest (OHCA) remain controversial, no studies on the topic from Finland have examined adherence to OHCA recommendations in real life. In response, the aim of this study was to document the interventions, success rates, and adverse events in airway management processes in OHCA, as well as to analyse survival at hospital discharge and at follow-up a year later. Methods: During a 6-month study period in 2010, data regarding all patients with OHCA and attempted resuscitation in southern and eastern Finland were prospectively collected. Emergency medical services (EMS) documented the airway techniques used and all adverse events related to the process. Study endpoints included the frequency of different techniques used, their success rates, methods used to verify the correct placement of the endotracheal tube, overall adverse events, and survival at hospital discharge and at follow-up a year later. Results: A total of 614 patients were included in the study. The incidence of EMS-attempted resuscitation was determined to be 51/100,000 inhabitants per year. The final airway technique was endotracheal intubation (ETI) in 413 patients (67.3 %) and supraglottic airway device (SAD) in 188 patients (30.2 %). The overall success rate of ETI was 92.5 %, whereas that of SAD was 85.0 %. Adverse events were reported in 167 of the patients (27.2 %). Having a prehospital EMS physician on the scene (p Conclusions: This study showed acceptable ETI and SAD success rates among Finnish patients with OHCA. Adverse events related to airway management were observed in more than 25 % of patients, and overall survival was 17.8 % at hospital discharge and 14.0 % after 1 year.Peer reviewe

Regional variation and outcome of out-of-hospital cardiac arrest (ohca) in Finland - the Finnresusci study

Peer reviewe

Introduction to GlobSnow Snow Extent products with considerations for accuracy assessment

Highlights • GlobSnow Snow Extent provides 17-years data record for Fractional snow cover (FSC). • Snow extent products cover the Northern Hemisphere in 0.01 deg. resolution. • FSC retrieval uses SCAmod method enabling fractional snow mapping also in forests. • Landsat TM/ETM+-based reference is not always representative for validation of FSC