1000 resultados para kartat - historialliset kartat - pohjoisnapa - 1701


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Shallow upland drains, grips, have been hypothesized as responsible for increased downstream flow magnitudes. Observations provide counterfactual evidence, often relating to the difficulty of inferring conclusions from statistical correlation and paired catchment comparisons, and the complexity of designing field experiments to test grip impacts at the catchment scale. Drainage should provide drier antecedent moisture conditions, providing more storage at the start of an event; however, grips have higher flow velocities than overland flow, thus potentially delivering flow more rapidly to the drainage network. We develop and apply a model for assessing the impacts of grips on flow hydrographs. The model was calibrated on the gripped case, and then the gripped case was compared with the intact case by removing all grips. This comparison showed that even given parameter uncertainty, the intact case had significantly higher flood peaks and lower baseflows, mirroring field observations of the hydrological response of intact peat. The simulations suggest that this is because delivery effects may not translate into catchment-scale impacts for three reasons. First, in our case, the proportions of flow path lengths that were hillslope were not changed significantly by gripping. Second, the structure of the grip network as compared with the structure of the drainage basin mitigated against grip-related increases in the concentration of runoff in the drainage network, although it did marginally reduce the mean timing of that concentration at the catchment outlet. Third, the effect of the latter upon downstream flow magnitudes can only be assessed by reference to the peak timing of other tributary basins, emphasizing that drain effects are both relative and scale dependent. However, given the importance of hillslope flow paths, we show that if upland drainage causes significant changes in surface roughness on hillslopes, then critical and important feedbacks may impact upon the speed of hydrological response. Copyright (c) 2012 John Wiley & Sons, Ltd.

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Schizophrenia is a neurodevelopmental disorder reflecting a convergence of genetic risk and early life stress. The slow progression to first psychotic episode represents both a window of vulnerability as well as opportunity for therapeutic intervention. Here, we consider recent neurobiological insight into the cellular and molecular components of developmental critical periods and their vulnerability to redox dysregulation. In particular, the consistent loss of parvalbumin-positive interneuron (PVI) function and their surrounding perineuronal nets (PNNs) as well as myelination in patient brains is consistent with a delayed or extended period of circuit instability. This linkage to critical period triggers (PVI) and brakes (PNN, myelin) implicates mistimed trajectories of brain development in mental illness. Strategically introduced antioxidant treatment or later reinforcement of molecular brakes may then offer a novel prophylactic psychiatry.

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Tutkielman tavoitteena oli antaa yleiskuva corporate governance -aiheen ympärillä käydystä kansallisesta ja kansainvälisestä keskustelusta ja siitä syntyneistä normistoista. Tavoitteena oli myös esimerkkiyrityksen kautta tarkastella suomalaisen keskustelun perusteella syntyneen normiston kolmea suositusta (liittyen hallintoneuvoston, hallituksen ja toimitusjohtajan päätöksenteolliseen asemaan). Mainittujen aihepiirien suosituksia on tutkimuksessa selvitetty laajemmin ja mukaan tarkasteluun on otettu kansallisella tasolla asioihin merkittävästi vaikuttava lainsäädäntö. Tutkimuksen case osuudessa tarkasteltiin valtio-omistajan antamia corporate governance suosituksia ja niiden toteutumista esimerkkiyrityksessä, Finnvera Oyj:ssa. Tutkielman yhteenvetona voidaan todeta, että kansainvälinen keskustelu eroaa aihepiireiltään jonkin verran suomalaisen keskustelun mielenkiinnon kohteista, joskin yhtymäkohtiakin on. Eroavaisuuteen vaikuttaa ainakin historialliset, kulttuurilliset ja institutionaaliset erot eri maiden kesken. Suomessa olemassa oleva yhtiölainsäädäntö on huomattavan kattava ja se osaltaan hoitaa sääntelyä ja siten poistaa tarvetta erillisille suosituksille ja pelisäännöille. Tutkimuksen case-yrityksessä Finnvera Oyj:ssa omistajan antamat toimenpidesuositukset corporate governance kysymysten käsittelystä on hoidettu asianmukaisesti, ja sillä tavoin kuin ne sovellettavuutensa perusteella on ollut tarkoituksenmukaista hoitaa.