405 research outputs found

    Shock waves in the dissipative Toda lattice

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    We consider the propagation of a shock wave (SW) in the damped Toda lattice. The SW is a moving boundary between two semi-infinite lattice domains with different densities. A steadily moving SW may exist if the damping in the lattice is represented by an ``inner'' friction, which is a discrete analog of the second viscosity in hydrodynamics. The problem can be considered analytically in the continuum approximation, and the analysis produces an explicit relation between the SW's velocity and the densities of the two phases. Numerical simulations of the lattice equations of motion demonstrate that a stable SW establishes if the initial velocity is directed towards the less dense phase; in the opposite case, the wave gradually spreads out. The numerically found equilibrium velocity of the SW turns out to be in a very good agreement with the analytical formula even in a strongly discrete case. If the initial velocity is essentially different from the one determined by the densities (but has the correct sign), the velocity does not significantly alter, but instead the SW adjusts itself to the given velocity by sending another SW in the opposite direction.Comment: 10 pages in LaTeX, 5 figures available upon regues

    Elinympäristöjen tilan edistämisen priorisoinnin periaatteet ja menetelmä

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    Tieteen tori: Metsien kestävä käyttö biotalouden aikan

    Tenojoen vesistöalueen kalastus- ja saalistilastot 2014–2016 : Katsaus tilastolliseen vuosiseurantaan

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    Vuonna 2016 lunastettujen kalastuslupien määrän perusteella paikkakuntalaisten lohenkalastuspaine Teno-Inarijoen pääuomassa väheni hieman. Suomen puolella lunastettiin yhteensä noin 700 kausilupaa. Kausilupien hinta oli hyvin edullinen (5 €), joten niitä lunastettiin usein myös ”varalta”, jos kalastus sattuisi hetkellisesti kiinnostamaan. Lohen verkko- tai patokalastukseen lunastettiin 335 lupaa, mutta arviolta vain noin 150 kalastajaa käytti verkkokalastusoikeuttaan. Vapa- ja viehekalastukseen, enimmäkseen lohensoutuun, paikkakuntalaiset lunastivat noin 380 lupaa. Norjan puolella paikkakuntalaiset kalastajat ovat viime vuosina lunastaneet noin 230 verkkopyynteihin oikeuttavaa kausilupaa ja 1 230 vapalupaa. Kalastuskaudella 2016 Tenojoella, Suomen puolella kävi noin 7 300 aikuisen kalastusmatkailijan lisäksi 850 kalastusta harrastavaa nuorta. Kalastusvuorokausien ja -matkailijoiden määrä väheni 6–7 % edellisvuodesta. Kalastusmatkailupaine jakautui Tenon eri lohkokuntiin melko tasaisesti. Joinakin vuosina Outakosken lohkokunnan ranta-alueet ja etenkin Inarijoen alajuoksun kalastuspaikat ovat houkutelleet runsaasti perhokalastuksen harrastajia. Inarin kunnan puolella, Inarijoen yläjuoksulla kalastusmatkailijoita on hyvin vähän. Kalastuskaudella 2016 Tenon rajajokialueella, Norjassa lunastettiin vain 730 vapakalastusvuorokautta, jotka kohdistuivat pääosin rantakalastukseen. Tenojoen sivujokialueilla, Utsjoen pääuomassa, Kevojoessa, Tsarsjoessa ja Vetsikkojoessa kalasti kalastuskaudella 2016 useita erityyppisiä kalastajaryhmiä. Paikkakuntalaiset ja ulkopaikkakuntalaiset osakaskalastajat saattoivat kalastaa kiinteistökohtaisella kalastusoikeudella (vapa- ja verkkopyynti) edellä mainittujen jokien yksityisvesialueilla. Lisäksi osakaskuntien kalastuslupia oli mahdollista luovuttaa muille lohenkalastuksen harrastajille. Kalastuskaudella 2016 Utsjoen osakaskunnasta lunastettiin noin 400 ja Vetsikon osakaskunnasta noin 70 osakaslupaa. Tilastointiin saatujen luovutusasiakirjojen mukaan osakkaat luovuttivat Utsjoen osakaskunnan vesialueille noin 390 lupaa (1 260 kalastusvuorokautta) ja Vetsikon osakaskunnan vesialueille noin 40 lupaa (60 kalastusvuorokautta). Kalastuskaudella 2016 Metsähallituksen sivuvesialueilla (Utsjoki, Vetsikkojoki) kalastus oli sallittu vain Utsjoella vakituisesti asuville henkilöille. Tenojoen lohisaalis kalastuskaudella 2016 oli 85 tonnia, josta 48 tonnia (56 %) saatiin Suomen puolella. Suomen puolelta tilastoitu saalis oli 11 % pienempi kuin edeltäneiden 40 vuoden keskisaalis. Vastaavalla tilastointiajanjaksolla Norjan puolelta tilastoitu saalis on pienentynyt 47 %. Viimeisten 15 vuoden aikana ei lohisaaliissa ole havaittu luonnollista, jaksottaista kannanvaihtelua. Lohisaalis jakautuu Suomessa ja Norjassa toisistaan poikkeavasti eri pyyntitavoille, mikä johtuu pääosin siitä, että Suomen puolella kalastusmatkailu lisää vapapyynnin saalisosuutta ja Norjassa, etenkin Tenojoen alajuoksulla, paikkakuntalaiset pyytävät lohta tehokkaasti ajoverkoilla (kulkuttamalla) ja lohipadoilla. Vuonna 2016 Tenojoen vesistön kokonaislohisaaliista saatiin verkkopyyntitavoilla 16 % ja vapapyynnillä 40 % Suomen puolelta ja vastaavasti verkkopyydyksillä 30 % ja vapapyynnillä 13 % Norjan puolelta. Perinteisten lohipatojen käyttö on vähentynyt molemmissa maissa, kalastajat ovat ikääntyneet ja tieto-taito on katoamassa. Kulkutuspyyntiin ovat sitä vastoin osallistuneet nuoremmatkin kalastajat. Kalastuskaudelle 2017 Tenojoen ja sen sivujokien lohenkalastukseen tuli voimaan uusia säädöksiä, jotka koskevat lupakiintiöitä, saaliskiintiöitä, saaliiden ilmoitusvelvollisuutta ja luvanmyyntikäytäntöjä, joten myös kalastuksen määrä sekä kalastuksen ja saaliiden tilastointi tulee muuttumaan.201

    Fatty acid characterization of Finnish organic milk - a farm survey

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    Bulk-tank milk samples were collected in January (2008) from 45 organic farms in Eastern Finland to examine their milk quality during winter feeding

    A stochastic model for heart rate fluctuations

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    Normal human heart rate shows complex fluctuations in time, which is natural, since heart rate is controlled by a large number of different feedback control loops. These unpredictable fluctuations have been shown to display fractal dynamics, long-term correlations, and 1/f noise. These characterizations are statistical and they have been widely studied and used, but much less is known about the detailed time evolution (dynamics) of the heart rate control mechanism. Here we show that a simple one-dimensional Langevin-type stochastic difference equation can accurately model the heart rate fluctuations in a time scale from minutes to hours. The model consists of a deterministic nonlinear part and a stochastic part typical to Gaussian noise, and both parts can be directly determined from the measured heart rate data. Studies of 27 healthy subjects reveal that in most cases the deterministic part has a form typically seen in bistable systems: there are two stable fixed points and one unstable one.Comment: 8 pages in PDF, Revtex style. Added more dat

    Tankyrase inhibition aggravates kidney injury in the absence of CD2AP

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    Inappropriate activation of the Wnt/beta-catenin pathway has been indicated in podocyte dysfunction and injury, and shown to contribute to the development and progression of nephropathy. Tankyrases, multifunctional poly(ADP-ribose) polymerase (PARP) superfamily members with features of both signaling and cytoskeletal proteins, antagonize Wnt/beta-catenin signaling. We found that tankyrases interact with CD2-associated protein (CD2AP), a protein essential for kidney ultrafiltration as CD2AP-knockout (CD2AP-/-) mice die of kidney failure at the age of 6-7 weeks. We further observed that tankyrase-mediated total poly-(ADP-ribosyl) ation (PARylation), a post-translational modification implicated in kidney injury, was increased in mouse kidneys and cultured podocytes in the absence of CD2AP. The data revealed increased activity of beta-catenin, and upregulation of lymphoid enhancer factor 1 (LEF1) (mediator of Wnt/beta-catenin pathway) and fibronectin (downstream target of Wnt/beta-catenin) in CD2AP-/- podocytes. Total PARylation and active beta-catenin were reduced in CD2AP-/- podocytes by tankyrase inhibitor XAV939 treatment. However, instead of ameliorating podocyte injury, XAV939 further upregulated LEF1, failed to downregulate fibronectin and induced plasminogen activator inhibitor-1 (PAI-1) that associates with podocyte injury. In zebrafish, administration of XAV939 to CD2AP-depleted larvae aggravated kidney injury and increased mortality. Collectively, the data reveal sustained activation of the Wnt/beta-catenin pathway in CD2AP-/- podocytes, contributing to podocyte injury. However, we observed that inhibition of the PARylation activity of tankyrases in the absence of CD2AP was deleterious to kidney function. This indicates that balance of the PARylation activity of tankyrases, maintained by CD2AP, is essential for normal kidney function. Furthermore, the data reveal that careful contemplation is required when targeting Wnt/beta-catenin pathway to treat proteinuric kidney diseases associated with impaired CD2AP.Peer reviewe

    Review on possible gravitational anomalies

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    This is an updated introductory review of 2 possible gravitational anomalies that has attracted part of the Scientific community: the Allais effect that occur during solar eclipses, and the Pioneer 10 spacecraft anomaly, experimented also by Pioneer 11 and Ulysses spacecrafts. It seems that, to date, no satisfactory conventional explanation exist to these phenomena, and this suggests that possible new physics will be needed to account for them. The main purpose of this review is to announce 3 other new measurements that will be carried on during the 2005 solar eclipses in Panama and Colombia (Apr. 8) and in Portugal (Oct.15).Comment: Published in 'Journal of Physics: Conferences Series of the American Institute of Physics'. Contribution for the VI Mexican School on Gravitation and Mathematical Physics "Approaches to Quantum Gravity" (Playa del Carmen, Quintana Roo, Mexico, Nov. 21-27, 2004). Updates to this information will be posted in http://www.lsc-group.phys.uwm.edu/~xavier.amador/anomalies.htm

    Framework for assessing and reversing ecosystem degradation – Report of the Finnish restoration prioritization working group on the options and costs of meeting the Aichi biodiversity target of restoring at least 15 percent of degraded ecosystems in Finland

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    This report is an abridged and revised English language edition of the original proposition of the Finnish restoration prioritization working group on the options and costs of restoring 15 percent of degraded ecosystems in Finland. We start with the key findings and the original propositions of the working group. Based on the experiences from Finland, we also provide a few new propositions for the international readership to help to plan and implement work towards meeting the global target of restoring 15 percent of the degraded ecosystems. In the beginning of the report, we describe the conceptual background of the work, i.e. that ecosystem degradation or improvement has a minimum of two components: the extent of area that has become degraded or restored and the magnitude of the degradation, or its counterpart improvement, at any given location. We then describe the procedure that we developed to systematically measure the magnitude of degradation from which the 15 percent can be calculated and the magnitude of improvement that different restoration measures can offer. The guiding principle adopted for the development of the procedure was to treat all ecosystems that are not in their natural state as degraded. However, it is worth emphasizing that the objective is not to reach the natural state of the ecosystems, but to reduce the degree of ecosystem degradation by restoration. With an example from herb-rich forests, we show how we prioritized restoration measures within an ecosystem. The prioritization was based on the effects of restoration measures on biodiversity and on the costs of the measures. We also considered the effect of restoration measures on some key ecosystem services. In addition to the restoration measures within each ecosystem, we also conducted prioritization among ecosystems. The prioritization among ecosystems is based on an analysis identifying the ecosystems where reasonable investments bring the greatest reduction in the degree of ecosystem degradation. The procedure thus enabled us to find the balanced and cost-effective restoration measure portfolios within each ecosystem type and to allocate resources effectively to those ecosystem types that provided highest benefits in terms of biodiversity and reduction of the degree of ecosystem degradation. To our knowledge, this report is the first to estimate the cost of meeting the 15 percent restoration target across all relevant terrestrial ecosystems in one country. Our work exemplifies that simultaneous prioritization among all major terrestrial ecosystems greatly reduces the overall cost of meeting the 15 percent restoration target. Indeed, if we focus on restoring 15 per cent of one ecosystem type at a time, which is the modus operandi in many parts of the world, the overall cost of meeting the 15 percent restoration target is more than twice compared to the prioritization approach we have adopted here. Rather than getting fixed on the 15 percent target, we also decided to provide additional options for decision makers. Thus, the report gives alternative answers to the question of which ecosystem restoration measures to take, at which scale and in which ecosystem types, in order to meet the overall target for ecosystem restoration in Finland
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