Weed problems in various tillage systems in the Nordic countries

There is an increasing use of various forms of reduced tillage or no-tillage in the Nordic countries. This will favour the growth of grass weed species and perennial species. Perennial creeping weeds like Elymus repens, Cirsium arvense, and Sonchus arvensis are important in all Nordic countries. Stationary weeds such as Taraxacum spp., Artemisia vulgaris and volunteer grassland species increase in areas with reduced tillage and especially no-tillage systems. Winter annual and biennial species such as Matricaria perforata, Poa annua, Alopecurus geniculatus and Stellaria media are frequently occuring weeds in reduced tillage systems in all countries, while Alopecurus myosuroides and Apera spica-venti are problems in Denmark and Southern parts of Sweden and Finland

A faster tree-decomposition based algorithm for counting linear extensions

We consider the problem of counting the linear extensions of an n-element poset whose cover graph has treewidth at most t. We show that the problem can be solved in time Õ(nt+3), where Õ suppresses logarithmic factors. Our algorithm is based on fast multiplication of multivariate polynomials, and so differs radically from a previous Õ(nt+4)-time inclusion–exclusion algorithm. We also investigate the algorithm from a practical point of view. We observe that the running time is not well characterized by the parameters n and t alone, fixing of which leaves large variance in running times due to uncontrolled features of the selected optimal-width tree decomposition. For selecting an efficient tree decomposition we adopt the method of empirical hardness models, and show that it typically enables picking a tree decomposition that is significantly more efficient than a random optimal-width tree decomposition. © Kustaa Kangas, Mikko Koivisto, and Sami Salonen; licensed under Creative Commons License CC-BY.Peer reviewe

Azimuthal asymmetry in ground-based GPS slant delay observations and their NWP model counterparts

International audienceThe ground-based measurements of the Global Positioning System (GPS) allow estimation of the tropospheric delay along the slanted signal paths through the atmosphere. The meteorological exploitation of such slant delay (SD) observations relies on the hypothesis of azimuthal asymmetry of the information content. This article addresses the validity of the hypothesis. The asymmetric properties of the SD observations and their model counterparts are investigated. In this study, the model counterparts are based on 3-h forecasts of a numerical weather prediction (NWP) model, run with four different horizontal resolutions. The SD observations are compared with their model counterparts with emphasis on cases of high asymmetry in order to see whether the observed asymmetry is a real atmospheric signature. The asymmetric delay component is found to be of the order of a few parts per thousand of the absolute SD value, thus barely exceeding the assumed standard deviation of the SD observation error. However, the observed asymmetric delay components show a statistically significant meteorological signal. Benefit of the asymmetric SD observations is therefore expected to be taken in future, when NWP systems will explicitly represent the small-scale atmospheric features revealed by the SD observations

Asymmetricity of ground-based GPS slant delay data

International audienceThe ground-based measurements of the Global Positioning System (GPS) allow estimation of the tropospheric delay along the slanted signal paths through the atmosphere. The meteorological exploitation of such slant delay (SD) observations relies on the hypothesis of azimuthal asymmetry of the information content. This article addresses the validity of the hypothesis. A new concept of asymmetricity is introduced for studying the SD observations and their model counterparts. The asymmetricity is defined as the ratio of the absolute asymmetric delay component to total SD. The model counterparts are determined from 3-h forecasts of a numerical weather prediction (NWP) model, run with four different horizontal resolutions. The SD observations are compared with their model counterparts with emphasis on cases of high asymmetricity in order to see whether the observed asymmetry is a real atmospheric signature. The asymmetricity is found to be of the order of a few parts per thousand. Thus, the asymmetric delay component barely exceeds the assumed standard deviation of the SD observation error. However, the observed asymmetric delay components show a statistically significant meteorological signal. Benefit of the asymmetric SD observations is therefore expected to be taken in future, when NWP systems will explicitly represent the small-scale atmospheric features revealed by the SD observations

Socioeconomic position, John Henryism, and incidence of acute myocardial infarction in Finnish men

Previous cross-sectional studies examining whether John Henryism (JH), or high-effort coping with socioeconomic adversity, potentiates the inverse association between socioeconomic position (SEP) and cardiovascular health have focused mainly on hypertension in African Americans. We conducted the first longitudinal test of this hypothesis on incident acute myocardial infarction (AMI) using data from the Kuopio Ischemic Heart Disease Risk Factor Study in Finland (N = 1405 men, 42-60 years). We hypothesized that the expected inverse gradient between SEP and AMI risk would be stronger for men scoring high on JH than for those scoring low. John Henryism was measured by a Finnish version of the JH Scale for Active Coping. Four different measures of SEP were used: childhood SEP, education, income, and occupation. AMI hazard ratios (HR) by SEP and JH were estimated using COX proportional hazard models, before and after adjustment for study covariates. 205 cases of AMI occurred over a median of 14.9 years. Men employed in lower rank (farmer, blue-collar) occupations who scored high on JH had significantly higher age-adjusted risks of AMI than men in higher rank (white-collar) occupations (HR = 3.14, 95% CI: 1.65-5.98 for blue collar; HR = 2.33, 95% Cl: 1.04-5.22 for farmers) who also scored high on JH. No socioeconomic differences in AMI were observed for men who scored low on JH (HR = 136, 95% CI: 0.74 2.47 for blue collar; HR = 0.93, 95% CI: 0.59-1.48 for farmers; p = 0.002 for the SEP x JH interaction). These findings persisted after adjustment for sociodemographic, behavioral, and biological factors. Results for other SEP measures were in the same direction, but did not reach statistical significance. Repetitive high-effort coping with adversity (John Henryism) was independently associated with increased risk for AMI in Finnish men, underscoring the potential relevance of the John Henryism hypothesis to CVD outcomes other than hypertension and to populations other than African Americans. (C) 2016 Published by Elsevier Ltd.Peer reviewe

Metabarcoding successfully tracks temporal changes in eukaryotic communities in coastal sediments

Metabarcoding is a method that combines high-throughput DNA sequencing and DNA-based identification. Previously, this method has been successfully used to target spatial variation of eukaryote communities in marine sediments, however, the temporal changes in these communities remain understudied. Here, we follow the temporal changes of the eukaryote communities in Baltic Sea surface sediments collected from two coastal localities during three seasons of two consecutive years. Our study reveals that the structure of the sediment eukaryotic ecosystem was primarily driven by annual and seasonal changes in prevailing environmental conditions, whereas spatial variation was a less significant factor in explaining the variance in eukaryotic communities over time. Therefore, our data suggests that shifts in regional climate regime or large-scale changes in the environment are the overdriving factors in shaping the coastal eukaryotic sediment ecosystems rather than small-scale changes in local environmental conditions or heterogeneity in ecosystem structure. More studies targeting temporal changes are needed to further understand the long-term trends in ecosystem stability and response to climate change. Furthermore, this work contributes to the recent efforts in developing metabarcoding applications for environmental biomonitoring, proving a comprehensive option for traditional monitoring approaches.Peer reviewe

Arresting bubble coarsening: A two-bubble experiment to investigate grain growth in presence of surface elasticity

Many two-phase materials suffer from grain-growth due to the energy cost which is associated with the interface that separates both phases. While our understanding of the driving forces and the dynamics of grain growth in different materials is well advanced by now, current research efforts address the question of how this process may be slowed down, or, ideally, arrested. We use a model system of two bubbles to explore how the presence of a finite surface elasticity may interfere with the coarsening process and the final grain size distribution. Combining experiments and modelling in the analysis of the evolution of two bubbles, we show that clear relationships can be predicted between the surface tension, the surface elasticity and the initial/final size ratio of the bubbles. We rationalise these relationships by the introduction of a modified Gibbs criterion. Besides their general interest, the present results have direct implications for our understanding of foam stability

Establishment of a spontaneously transformed cell line (JU-PI) from a myxoinflammatory fibroblastic sarcoma

cited By 0Myxoinflammatory fibroblastic sarcoma is a soft-tissue neoplasm most frequently found in the distal extremities of middle-aged adults. Most myxoinflammatory fibroblastic sarcoma are low-grade tumors with propensity for local recurrence after incomplete removal. We report a myxoinflammatory fibroblastic sarcoma which developed in the foot of a 41-year-old male and showed an exceptionally aggressive course with metastatic spread and fatal outcome within 16 months. We managed to establish a spontaneously transformed continuous cell line, called JU-PI, from a metastatic lesion. The JU-PI cells have a sub-tetraploid karyotype including the 1;10 chromosomal translocation and amplification of the proximal end of 3p; these features are considered genetic signatures of myxoinflammatory fibroblastic sarcoma. Both the primary tumor and the JU-PI cells showed nuclear expression of the TFE3 transcription factor but TFE3-activating chromosomal rearrangements were not found. To our knowledge, JU-PI is the first established myxoinflammatory fibroblastic sarcoma cell line. JU-PI cells offer a tool for investigating the molecular oncology of myxoinflammatory fibroblastic sarcoma. © 2018, © The Author(s) 2018.Peer reviewe

How to Support Prison Workers’ Perceived Readiness to Identify and Respond to Possible Gambling Problems : a Pilot Study from Two Finnish Prisons

Problem gambling is known to be prevalent among prisoners. However, it is not systematically screened and often remains undetected. This pilot study explores prison workers’ (N = 21) knowledge, views, and opinions about problem gambling in two Finnish prisons with a view to improving training and to developing better guidelines for identifying and responding to gambling problems. Four-fifths (81%) of prison workers considered problem gambling a serious issue in Finland. During the past year, more than nine in ten (94.1%) had encountered a prisoner with a gambling problem. Problem gambling was identified in connection with discussions about prisoners’ illegal activity (50%), financial situation (25%), or other problems (25%). Nearly half of the participants felt they did not have adequate training or information about problem gambling and related issues and expressed an interest in continuing education. This pilot study provides important direction for the development of tailored training programs for prison workers. The next step is to increase awareness of gambling programs in a wider national context and to develop and evaluate the effectiveness of training programs.Peer reviewe