Effects of insect harassment on weight gain and survival in reindeer calves

Relationships between insect harassment and the weight gain and survival of reindeer calves were studied in two areas in Finland north of the Arctic Circle. The level of insect harassment explained a significant amount of the yearly variation in calf weights determined in autumn or early winter in both areas and directly influenced calf mortality in one of them. The lowest weights and calf percents were experienced in years when a bad winter was followed by a warm summer with severe insect harassment.Råkån vaikutus poronvasojen painonlisåykseen ja eloonjååmiseen.Abstract in Finnish / Tiivistelmd: Rakan (vertaimevat ja porossa loisivat hyonteiset) vaikutusta vasojen painoon ja vasaprosenttiin tutkittiin Alakylan paliskunnassa sekå Kaldoaivi - Paistunturin alueella. Kummallakin alueella rakka selitti huomattavan osan vasojen syyspainojen vuosivaihtelusta ja Kaldoaivi - Paistunturissa se vaikutti suoraan myos vasaprosenttiin. Vasojen painot ja vasaprosentit olivat alhaisimmat vuosina, joina vaikeaa talvea seurasi kuuma, hyonteisille suotuisa kesa.Effekter av insektforstyrrelser på vektøkning og overlevelse av reinkalver.Abstract in Swedish / Sammendrag: Effekter av insektforstyrrelser på vektøkning og overlevelse av reinkalver er studert i to områder av Finland nord for Polarsirkelen. Graden av insektforstyrrelser forklarte en signifikant andel av variasjonene fra år til år i kalvevekter bestemt høst eller tidlig vinter for begge områder. Den virket også direkte inn på kalvedødeligheten i et av områdene. De laveste vekter og kalveprosenter fant man i år der en dårlig vinter ble etterfulgt av en varm sommer med alvorlige insektforstyrrelser

The growth rate of Cladonia rangiferina and C. mitis in relation to forest characteristics in northeastern Finland

The growth rate of Cladonia rangiferina and C. mitis was studied in Kuusamo, northeastern Finland, where they share more than 90 percent of the total lichen biomass. The material was collected from 5 pine forests of different ages in Calluna-Cladina heaths. The length growth rate of C. rangiferina varied by site from 3.9 to 4.3 mmyr -' and that of C. mitis from 3.0 to 3.5 mmyr-1 C. rangiferina achieved the fastest growth in a younger (60 years) shadowy forest; growth was slowest in a clear-felled area and in an old (180 years), already thinned forest. C. mitis grew fastest in a site with young (10 years old) pine plants and slowest in a younger shadowy site. The results do not support suggestions that clear-felling itself might negatively influence the growth of lichens. However, it is important also from the point of view of range management to create a new forest as soon as possible, since both species studied here grew faster in young forests than in clear-felled areas.Harmaaporonjakalan ja mietoporonjakalan kasvunopeus eri-ikaisissa metsissa.Abstract in Finnish / Yhteenveto: Harmaaporonjakalan (Cladonia rangiferina) ja mietoporonjakalan (Cladonia mitis) kasvunopeutta tutkittiin Kuusamossa. Aineisto kerattiin 5 puustoltaan eri-ikaiselti jakalakankaalta. Harmaaporonjakala kasvoi pituutta keskimaarin 3.9 - 4.3 mm/v ja mietoporonjakala 3.0 - 3.5 mm/v kasvupaikasta riippuen. Harmaaporonjakalan kasvu oli nopeinta nuorehkossa (60 v) tiheassa metsassa, hitainta paljaaksihakkuulla ja vanhassa (180 v), jo harventuneessa metsassa. Mietoporonjakala kasvoi nopeimmin 90 cm:n taimikossa ja hitaimmin varjoisimmalla kasvupaikalla. Tulosten perusteella on vaikea yhtya kasitykseen, etta paljaaksihakkuu sinansa vahentaa poronjakalien kasvunopeutta. Myos poronhoidon kannalta on kuitenkin tarkeaa, etta uusi metsa saadaan aikaan mahdollisimman nopeasti, silla molemmat lajit kasvavat nopeimmin eri-ikaisissa nuorissa metsissa

Diagnosis, natural course and treatment outcomes of groove pancreatitis

Background: Groove pancreatitis (GP) is a rare form of chronic pancreatitis with limited data on its diagnostics and treatment outcomes. The aim of this study was to assess its diagnostics, natural course, and treatment options. Methods: The study is a retrospective population-based study from Southern Finland, including all patients with suspected GP between January 2005 and December 2015. Two certified gastrointestinal radiologists re-reviewed the imaging studies. The radiological re-review, clinical judgment, and final histopathology confirmed the GP diagnoses. Results: Out of 67 patients with possible GP, 39 patients were considered to have high radiological certainty of GP. Out of these 39, five patients had cancer instead. Thirty-three patients with confirmed GP formed the final study cohort. Patients with GP were mostly middle-aged (median 55 years) men. All had at least moderate alcohol consumption. No intervention was needed in 14 patients. In five-year follow-up all conservatively treated patients became asymptomatic, while 10 out of 16 patients undergoing at least one intervention were asymptomatic at five years. Conclusion: The radiological diagnosis of GP is difficult, and a low threshold for cancer suspicion should be kept. Symptoms of GP decrease with time and suggest conservative treatment as the first-line option.Peer reviewe

Validity of the Polar V800 heart rate monitor to measure RR intervals at rest

Purpose To assess the validity of RR intervals and short-term heart rate variability (HRV) data obtained from the Polar V800 heart rate monitor, in comparison to an electrocardiograph (ECG). Method Twenty participants completed an active orthostatic test using the V800 and ECG. An improved method for the identification and correction of RR intervals was employed prior to HRV analysis. Agreement of the data was assessed using intra-class correlation coefficients (ICC), Bland–Altman limits of agreement (LoA), and effect size (ES). Results A small number of errors were detected between ECG and Polar RR signal, with a combined error rate of 0.086 %. The RR intervals from ECG to V800 were significantly different, but with small ES for both supine corrected and standing corrected data (ES 0.999 for both supine and standing corrected intervals. When analysed with the same HRV software no significant differences were observed in any HRV parameters, for either supine or standing; the data displayed small bias and tight LoA, strong ICC (>0.99) and small ES (≤0.029). Conclusions The V800 improves over previous Polar models, with narrower LoA, stronger ICC and smaller ES for both the RR intervals and HRV parameters. The findings support the validity of the Polar V800 and its ability to produce RR interval recordings consistent with an ECG. In addition, HRV parameters derived from these recordings are also highly comparable

The mycorrhizal tragedy of the commons

Trees receive growth-limiting nitrogen from their ectomycorrhizal symbionts, but supplying the fungi with carbon can also cause nitrogen immobilization, which hampers tree growth. We present results from field and greenhouse experiments combined with mathematical modelling, showing that these are not conflicting outcomes. Mycorrhizal networks connect multiple trees, and we modulated C provision by strangling subsets of Pinus sylvestris trees, assuming that carbon supply to fungi was reduced proportionally to the strangled fraction. We conclude that trees gain additional nitrogen at the expense of their neighbours by supplying more carbon to the fungi. But this additional carbon supply aggravates nitrogen limitation via immobilization of the shared fungal biomass. We illustrate the evolutionary underpinnings of this situation by drawing on the analogous tragedy of the commons, where the shared mycorrhizal network is the commons, and explain how rising atmospheric CO2 may lead to greater nitrogen immobilization in the future

Time-Frequency based Feature Selection for Discrimination of non stationary Biosignals.

This research proposes a generic methodology for dimensionality reduction upon time-frequency representations applied to the classification of different types of biosignals. The methodology directly deals with the highly redundant and irrelevant data contained in these representations, combining a first stage of irrelevant data removal by variable selection, with a second stage of redundancy reduction using methods based on linear transformations. The study addresses two techniques that provided a similar performance: the first one is based on the selection of a set of the most relevant time?frequency points, whereas the second one selects the most relevant frequency bands. The first methodology needs a lower quantity of components, leading to a lower feature space; but the second improves the capture of the time-varying dynamics of the signal, and therefore provides a more stable performance. In order to evaluate the generalization capabilities of the methodology proposed it has been applied to two types of biosignals with different kinds of non-stationary behaviors: electroencephalographic and phonocardiographic biosignals. Even when these two databases contain samples with different degrees of complexity and a wide variety of characterizing patterns, the results demonstrate a good accuracy for the detection of pathologies, over 98%.The results open the possibility to extrapolate the methodology to the study of other biosignals

Optimal stomatal behaviour around the world

This is the author accepted manuscript. The final version is available from Springer Nature via the DOI in this recordStomatal conductance (g s) is a key land-surface attribute as it links transpiration, the dominant component of global land evapotranspiration, and photosynthesis, the driving force of the global carbon cycle. Despite the pivotal role of g s in predictions of global water and carbon cycle changes, a global-scale database and an associated globally applicable model of g s that allow predictions of stomatal behaviour are lacking. Here, we present a database of globally distributed g s obtained in the field for a wide range of plant functional types (PFTs) and biomes. We find that stomatal behaviour differs among PFTs according to their marginal carbon cost of water use, as predicted by the theory underpinning the optimal stomatal model and the leaf and wood economics spectrum. We also demonstrate a global relationship with climate. These findings provide a robust theoretical framework for understanding and predicting the behaviour of g s across biomes and across PFTs that can be applied to regional, continental and global-scale modelling of ecosystem productivity, energy balance and ecohydrological processes in a future changing climate.This research was supported by the Australian Research Council (ARC MIA Discovery Project 1433500-2012-14). A.R. was financially supported in part by The Next-Generation Ecosystem Experiments (NGEE-Arctic) project, which is supported by the Office of Biological and Environmental Research in the Department of Energy, Office of Science, and through the United States Department of Energy contract No. DE-AC02-98CH10886 to Brookhaven National Laboratory. M.O.d.B. acknowledges that the Brassica data were obtained within a research project financed by the Belgian Science Policy (OFFQ, contract number SD/AF/02) and coordinated by K. Vandermeiren at the Open-Top Chamber research facilities of CODA-CERVA (Tervuren, Belgium)

Optimal stomatal behaviour around the world

© 2015 Macmillan Publishers Limited. All rights reserved. Stomatal conductance (g s) is a key land-surface attribute as it links transpiration, the dominant component of global land evapotranspiration, and photosynthesis, the driving force of the global carbon cycle. Despite the pivotal role of g s in predictions of global water and carbon cycle changes, a global-scale database and an associated globally applicable model of g s that allow predictions of stomatal behaviour are lacking. Here, we present a database of globally distributed g s obtained in the field for a wide range of plant functional types (PFTs) and biomes. We find that stomatal behaviour differs among PFTs according to their marginal carbon cost of water use, as predicted by the theory underpinning the optimal stomatal model and the leaf and wood economics spectrum. We also demonstrate a global relationship with climate. These findings provide a robust theoretical framework for understanding and predicting the behaviour of g s across biomes and across PFTs that can be applied to regional, continental and global-scale modelling of ecosystem productivity, energy balance and ecohydrological processes in a future changing climate

The Origin of Glucocorticoid Hormone Oscillations

Characterization of a peripheral hormonal system identifies the origin and mechanisms of regulation of glucocorticoid hormone oscillations in rats