Modeling of Isotropic Backward-Wave Materials Composed of Resonant Spheres

A possibility to realize isotropic artificial backward-wave materials is theoretically analyzed. An improved mixing rule for the effective permittivity of a composite material consisting of two sets of resonant dielectric spheres in a homogeneous background is presented. The equations are validated using the Mie theory and numerical simulations. The effect of a statistical distribution of sphere sizes on the increasing of losses in the operating frequency band is discussed and some examples are shown.Comment: 15 pages, 7 figure

Backward-wave regime and negative refraction in chiral composites

Possibilities to realize a negative refraction in chiral composites in in dual-phase mixtures of chiral and dipole particles is studied. It is shown that because of strong resonant interaction between chiral particles (helixes) and dipoles, there is a stop band in the frequency area where the backward-wave regime is expected. The negative refraction can occur near the resonant frequency of chiral particles. Resonant chiral composites may offer a root to realization of negative-refraction effect and superlenses in the optical region

Global warming will affect the maximum potential abundance of boreal plant species

Forecasting the impact of future global warming on biodiversity requires understanding how temperature limits the distribution of species. Here we rely on Liebig's Law of Minimum to estimate the effect of temperature on the maximum potential abundance that a species can attain at a certain location. We develop 95%‐quantile regressions to model the influence of effective temperature sum on the maximum potential abundance of 25 common understory plant species of Finland, along 868 nationwide plots sampled in 1985. Fifteen of these species showed a significant response to temperature sum that was consistent in temperature‐only models and in all‐predictors models, which also included cumulative precipitation, soil texture, soil fertility, tree species and stand maturity as predictors. For species with significant and consistent responses to temperature, we forecasted potential shifts in abundance for the period 2041–2070 under the IPCC A1B emission scenario using temperature‐only models. We predict major potential changes in abundance and average northward distribution shifts of 6–8 km yr−1. Our results emphasize inter‐specific differences in the impact of global warming on the understory layer of boreal forests. Species in all functional groups from dwarf shrubs, herbs and grasses to bryophytes and lichens showed significant responses to temperature, while temperature did not limit the abundance of 10 species. We discuss the interest of modelling the ‘maximum potential abundance’ to deal with the uncertainty in the predictions of realized abundances associated to the effect of environmental factors not accounted for and to dispersal limitations of species, among others. We believe this concept has a promising and unexplored potential to forecast the impact of specific drivers of global change under future scenarios.202

Isolation of Clostridium limosum from an outbreak of metritis in farmed mink

BACKGROUND: An outbreak of sudden death of pregnant farmed mink in Finland occurred during the busiest whelping period in the spring of 2013. The affected farms were all located in western Finland in a rather narrow geographic area, Ostrobothnia. Dead mink from 22 farms were submitted for laboratory diagnostics to the Finnish Food Safety Authority (Evira). The carcasses were necropsied and tissue specimens were prepared for histology. Samples of internal organs and peritoneal fluid were cultured bacteriologically. RESULTS: Major pathological findings included hemorrhagic vaginal discharge, severely inflamed uteri with luminal hemorrhagic exudate and dead fetuses. Dead fetuses were present in the peritoneal cavity and associated severe peritonitis occurring as sequela of uterine rupture were found in most minks. Histological findings included hemorrhages, neutrophil infiltrations, degenerative inflammatory cells, edema, fibrin and rod-shaped bacteria on all layers of the uterine wall. In most samples abundant and pure anaerobic bacterial growth of Clostridium limosum was found. CONCLUSIONS: This is the first report of C. limosum associated metritis in farmed mink. Disease was only observed in pregnant females and the uterus was the primary site of infection. The source of infection and the route of transmission remained unclear, but feed borne transmission was suspected

Growing season precipitation in Finland under recent and projected climate

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Thermal seasons in northern Europe in projected future climate

Global warming acts to prolong thermal summers and shorten winters. In this work, future changes in the lengths and timing of four thermal seasons in northern Europe, with threshold temperatures 0 and 10 degrees C, are derived from bias-adjusted output data from 23 CMIP5 global climate models. Three future periods and two Representative Concentration Pathway (RCP) scenarios are discussed. The focus is on the period 2040-2069 under RCP4.5, which approximately corresponds to a 2 degrees C global warming relative to the preindustrial era. By the period 2040-2069, the average length of the thermal summer increases by nearly 30 days relative to 1971-2000, and the thermal winter shortens by 30-60 days. The timing of the thermal springs advances while autumns delay. Within the model ensemble, there is a high linear correlation between the modelled annual-mean temperature increase and shifts in the thermal seasons. Thermal summers lengthen by about 10 days and winters shorten by 10-24 days per 1 degrees C of local warming. In the mid-21st century, about two-thirds of all summers (winters) are projected to be very long (very short) according to the baseline-period standards, with an anomaly greater than 20 days relative to the late-20th century temporal mean. The proportion of years without a thermal winter increases remarkably in the Baltic countries and southern Scandinavian peninsula. Implications of the changing thermal seasons on nature and human society are discussed in a literature review.Peer reviewe

Turbulence Properties of Interplanetary Coronal Mass Ejections in the Inner Heliosphere: Dependence on Proton Beta and Flux Rope Structure

Interplanetary coronal mass ejections (ICMEs) have low proton beta across a broad range of heliocentric distances and a magnetic flux rope structure at large scales, making them a unique environment for studying solar wind fluctuations. Power spectra of magnetic field fluctuations in 28 ICMEs observed between 0.25 and 0.95 au by Solar Orbiter and Parker Solar Probe have been examined. At large scales, the spectra were dominated by power contained in the flux ropes. Subtraction of the background flux rope fields reduced the mean spectral index from $-5/3$ to $-3/2$ at $kd_i \leq 10^{-3}$. Rope subtraction also revealed shorter correlation lengths in the magnetic field. The spectral index was typically near $-5/3$ in the inertial range at all radial distances regardless of rope subtraction, and steepened to values consistently below $-3$ with transition to kinetic scales. The high-frequency break point terminating the inertial range evolved approximately linearly with radial distance and was closer in scale to the proton inertial length than the proton gyroscale, as expected for plasma at low proton beta. Magnetic compressibility at inertial scales did not show any significant correlation with radial distance, in contrast to the solar wind generally. In ICMEs, the distinctive spectral properties at injection scales appear mostly determined by the global flux rope structure while transition-kinetic properties are more influenced by the low proton beta; the intervening inertial range appears independent of both ICME features, indicative of a system-independent scaling of the turbulence.Comment: 12 pages, 5 figures; accepted for publication in the Astrophysical Journal Letters 2023 September 2

Personality disorders and suicide attempts in unipolar and bipolar mood disorders

Background: Comorbid personality disorders may predispose patients with mood disorders to suicide attempts (SAs), but factors mediating this effect are not well known. Methods: Altogether 597 patients from three prospective cohort studies (Vantaa Depression Study, Jorvi Bipolar Study, and Vantaa Primary Care Depression Study) were interviewed at baseline, at 18 months, and in VDS and PC-VDS at 5 years. Personality disorders (PDs) at baseline, number of previous SAs, life-charted time spent in major depressive episodes (MDEs), and precise timing of SAs during follow-up were determined and investigated. Results: Overall, 219 (36.7%) patients had a total of 718 lifetime SAs; 88 (14.7%) patients had 242 SAs during the prospective follow-up. Having any PD diagnosis increased the SA rate, both lifetime and prospectively evaluated, by 90% and 102%, respectively. All PD clusters increased the rate of new SAs, although cluster C PDs more than the others. After adjusting for time spent in MDEs, only cluster C further increased the SA rate (by 52%). Mediation analyses of PD effects on prospectively ascertained SAs indicated significant mediated effects through time at risk in MDEs, but also some direct effects. Limitations: Findings generalizable only to patients with mood disorders. Conclusions: Among mood disorder patients, comorbid PDs increase the risk of SAs to approximately two-fold. The excess risk is mostly due to patients with comorbid PDs spending more time in depressive episodes than those without. Consequently, risk appears highest for PDs that most predispose to chronicity and recurrences. However, also direct risk-modifying effects of PDs exist. (C) 2015 Elsevier B.V. All rights reserved.Peer reviewe

Worldwide survey of awareness and needs concerning reanalyses, and respondents views on climate services

A worldwide online survey about user awareness of reanalyses and climate services was conducted in the period from November 2013 to February 2014 by the Coordinating Earth Observation Data Validation for Re-Analysis for Climate Services (CORE-CLIMAX) project. The 2,578 respondents were mostly users of global reanalyses [particularly the European Centre for Medium-Range Weather Forecasts (ECMWF), National Centers for Environmental Prediction (NCEP), National Aeronautics and Space Administration (NASA), and Japan Meteorological Agency (JMA) reanalyses]. They answered queries arranged in 11 sections by choosing from preprepared check box responses and left several hundred free comments. Here, we analyze responses related to characteristics of reanalysis data and the perceived obstacles for using reanalysis in climate services. After examining responses from all survey participants, we focus on the answers from subgroups working in specific disciplines related to natural resource management: freshwater, agriculture and food production, forestry, and energy. Although the survey attracted mostly self-selected respondents from the education and public research and development (R&D) sectors, one-third of the energy-related subgroup were from the private sector. A large majority (91%) of the respondents use ECMWF reanalyses, but other reanalysis products are also widely used by them. Respondents expressed desire for reanalysis development in the areas of 1) training and online plotting tools, 2) more frequent updates, 3) explanations about uncertainties (the energy subgroup emphasizes this), 4) smaller biases, 5) less restrictive data policy, and 6) higher temporal and spatial resolution (the energy and water subgroups highlight this). Additionally, the subgroups (excluding energy) expressed interest in including in future climate services activities for applied weather and climate research for impact assessment and/or statistical impact analyses for improving weather warnings and their criteria.Peer reviewe

The Barents area changes – How will Finland adapt? (Barentsin alue muuttuu – miten Suomi sopeutuu?)

The cumulative impacts of environmental, climatic and societal changes and their consequences will affect the development of the Arctic region in the coming decades. Adaptation to these changes will require measures of all the actors in the region. Finland, part of the Euro-Arctic region, will adapt to these changes in a variety of ways. The Barents area is unique in the Arctic in being a multicultural, relatively densely populated area with well-developed industries and infrastructure. This report examines adaptation to changes and their consequences in the Barents area in terms of governance and Finland’s capacities to adapt. The aim has been to produce comprehensive information from the Finnish perspective for local and national decision-makers about long-term changes in the region, their expected impacts and adaptation options, and to support decision-making that will advance adaptation. The report includes recommendations. This report is based on the contribution of Finnish experts to an Arctic Council and Arctic Monitoring and Assessment Programme (AMAP) project titled ”Adaptation Actions for a Changing Arctic” (AACA). The project has prepared a pilot report by Nordic and Russian experts on the Barents area in English on changes, their impacts and adaptation options. The report will be published in 2017 (AMAP 2017)