937 research outputs found

    Validity of the single-particle description and charge noise resilience for multielectron quantum dots

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    We construct an optimal set of single-particle states for few-electron quantum dots (QDs) using the method of natural orbitals (NOs). The NOs include also the effects of the Coulomb repulsion between electrons. We find that they agree well with the noniteracting orbitals for GaAs QDs of realistic parameters, while the Coulomb interactions only rescale the radius of the NOs compared to the noninteracting case. We use NOs to show that four-electron QDs are less susceptible to charge noise than their two-electron counterparts.Comment: 11+ pages, 5 figure

    Drift compensation using a multichannel slot waveguide Young interferometer

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    Polymeric integrated Young interferometer sensor chips utilizing a slot waveguide have demonstrated to be sensitive, to work at visible wavelengths, to be manufacturable by simple process, and to have a reduced sensitivity to temperature fluctuations. Although slot waveguide Young interferometers have these desirable features for low-cost rapid diagnostics, the sensor readout is disturbed by mechanical drifts of the sensing system. In this paper we demonstrate that mechanical drifts of the readout system can be compensated by using a multichannel slot waveguide Young interferometer having two reference waveguides and applying a drift compensation method based on the analysis of the spatial shifts of the interferogram fringes. The applicability of the drift compensation method was studied by conducting experiments with undisturbed and with mechanically disturbed setup to measure the phase changes induced by the changes of the bulk refractive index. By applying the drift compensation method, the sample induced phase change responses were extracted from up to 18 times larger measured phase changes in the disturbed experiments proving the applicability of the method with multichannel slot waveguide Young interferometers

    A conceptual framework for the future of sea-level rise and land uplift changes in the Vaasa region of Finland

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    This paper uses the Vaasa region of Finland as an illustrative case study to explore how the relationships between climate change, sea-level rise and land uplift may offer applications in forecasting future land uplift changes. Using a comparative literature review and analysis of open source data, a conceptual framework is developed to ex-amine causes-effect relationships between them. The sea-level rise around the world by the end of the 21st century shows dramatic effects all over the world. However, the rate of land uplift in the Vaasa region is higher than the rate of sea-level rise. This localised finding is different from global average rates for land uplift and sea-level rise. This indicates that although climate change is global, it can lead to very different regional expressions. This paper presents a first attempt to combine sea-level rise and land uplift into a single cohesive framework to sup-port future land uplift management. The results of this paper establish a conceptual framework for studies of vulnerability and adaptation to climate change that can ben-efit local, regional and global communities

    Effects of four different antihypertensive drugs on plasma metabolomic profiles in patients with essential hypertension

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    Objective In order to search for metabolic biomarkers of antihypertensive drug responsiveness, we measured > 600 biochemicals in plasma samples of subjects participating in the GENRES Study. Hypertensive men received in a double-blind rotational fashion amlodipine, bisoprolol, hydrochlorothiazide and losartan, each as a monotherapy for one month, with intervening one-month placebo cycles. Methods Metabolomic analysis was carried out using ultra high performance liquid chromatography-tandem mass spectrometry. Full metabolomic signatures (the drug cycles and the mean of the 3 placebo cycles) became available in 38 to 42 patients for each drug. Blood pressure was monitored by 24-h recordings. Results Amlodipine (P values down to 0.002), bisoprolol (P values down to 2 x 10(-5)) and losartan (P values down to 2 x 10(-4)) consistently decreased the circulating levels of long-chain acylcarnitines. Bisoprolol tended to decrease (P values down to 0.002) the levels of several medium-and long-chain fatty acids. Hydrochlorothiazide administration was associated with an increase of plasma uric acid level (P = 5 x 10(-4)) and urea cycle metabolites. Decreases of both systolic (P = 0.06) and diastolic (P = 0.04) blood pressure after amlodipine administration tended to associate with a decrease of plasma hexadecanedioate, a dicarboxylic fatty acid recently linked to blood pressure regulation. Conclusions Although this systematic metabolomics study failed to identify circulating metabolites convincingly predicting favorable antihypertensive response to four different drug classes, it provided accumulating evidence linking fatty acid metabolism to human hypertension.Peer reviewe

    Jääkäriliikkeen muistomerkit, toiminta ja muistaminen Oulun ja Tervolan välisellä alueella

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    Tiivistelmä. Tutkielmassa tarkastelen jääkäritoimintaan liittyviä muistomerkkejä Oulun sekä Tervolan välisellä alueella sekä niihin liittyviä muistamisen muotoja. Muistomerkkejä tutkimukseen olen valinnut Oulusta, Simosta, Kemistä, Keminmaasta, Torniosta, Haaparannasta sekä Tervolasta. Tutkielmassani tarkastelen suurempia muistopatsaita eli niin sanottuja päämuistomerkkejä, muistolaattoja sekä muita muistin paikkoja, kuten jääkärikämppien kopiota. Tutkielmassa käyn läpi minkälaisia, mihin ja milloin muistomerkkejä on pystytetty. Tarkastelen paljastustilaisuuksia ja erityisesti niissä pidettyjä puheita, joiden kautta tuodaan esille sitä, miksi muistomerkit on pystytetty ja mikä niiden tarkoitus on. Analysoin minkälaisia kuva-aiheita, tyylejä ja tekstejä muistomerkeissä esiintyy ja mistä ne on rakennettu. Muistomerkkeihin kohdistuu toimintaa eli rituaaleja, joiden kautta muistia ylläpidetään. Tutkielmassa käyn läpi, minkälaista toimintaa jääkäriliikkeen muistomerkkeihin kohdistetaan ja kenen toimesta. Näiden kautta pääsee käsiksi siihen, mitä jääkäreistä ja jääkäriliikkeestä halutaan muistaa ja mitä ei. Jääkäriliikkeen muistomerkit on pystytetty muistuttamaan tulevia sukupolvia jääkäreistä sekä heitä etappitoiminnan aikana auttaneista paikallisista ihmisistä. Kuva-aiheiltaan ja teksteiltään useimmat muistomerkit ovat pelkistettyjä. Niissä on jääkärimerkki sekä maininta etappireitistä tai jääkäriliikkeestä. Tornion muistomerkissä on monia erilaisia kuva-aiheita ja tekstejä ja se on ainoa muistomerkki, jossa on tekstin kautta huomioitu etappitoiminnassa mukana olleet naiset. Simon muistomerkin tekstissä venäläiset mainitaan ryssinä. Toisen maailmansodan jälkeen valvontakomission toimesta useita muistomerkkejä muutettiin sanan ryssä takia, mutta Simon muistomerkkiä ei syystä tai toisesta muokattu. Materiaalivalinnoilla on tärkeä rooli muistomerkin säilymisen kannalta. Muistomerkeissä on käytetty kestäviä materiaaleja, kuten betonia, graniittia ja mukulakiveä. Graniitilla ja mukulakivillä on lisäksi kansallisen identiteetin kannalta tärkeitä merkityksiä, joita myös jääkärien muistomerkeillä korostetaan. Rituaaleja suoritetaan tiettyinä jääkäriliikkeen kannalta tärkeinä päivämäärinä. Yleisin rituaali on seppeleen laskeminen muistomerkille. Itsenäisyyspäivänä jääkäreiden muistoa vaalivien järjestöjen toimesta käydään sytyttämässä kynttilöitä muistomerkeille. Paikallisia muistojuhlia järjestetään Keminmaassa Kivalon jääkärikämpällä ja Simossa Simon kahakan tapahtumapaikalla muistomerkin läheisyydessä. Simon kahakan muistojuhlan rituaaleihin kuului vuonna 2016 kahakasta tehty näytelmä, joka esitettiin alkuperäisellä tapahtumapaikalla. Jääkäreiden kotiinpaluun muistojuhlaa vietetään suuremmassa mittakaavassa kymmenvuotisjuhlin, jolloin Vaasassa järjestetään Puolustusvoimien paraati. Jääkäreiden muistaminen on sekä julkista että yhteisöllistä muistamista. Jääkäreitä ei aina ole haluttu muistaa tai joitakin asioita on haluttu unohtaa. Kemin muistomerkin kohdalla kaupunki ei halunnut olla mukana muistomerkin hankkimisessa eikä paljastamisessa. Simon muistomerkissä ei mainita Simon kahakassa jääkäreitä vastaan taistelleita suomalaisia poliiseja, heidät on haluttu unohtaa

    Soil bacterial community in potato tuberosphere following repeated applications of a common scab suppressive antagonist

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    Disease suppressive soils are important for managing soil-borne diseases that cannot be controlled with chemicals. One such disease is the potato common scab caused by Streptomyces species. Suppressiveness against common scab can develop spontaneously in fields where potato is grown for years without interruption, and this has been attributed to non-pathogenic Streptomyces strains. Streptomyces spp. have been used as inoculants in biological control, but their long-term effects have gained less attention. In our previous studies, a nonpathogenic Streptomyces strain (Str272) isolated from a potato common scab lesion suppressed common scab in field trials lasting over 5 years. In this study, bacterial communities in the tuberosphere i.e. in the soil adjacent to potato tubers, were analysed by next generation sequencing (NGS). The aim was to compare bacterial communities in untreated control plots to those in which seed tubers were treated with Str272 in one or several growing seasons. Str272 applications increased soil bacterial diversity and affected the bacterial composition in the potato tuberosphere. The most pronounced differences were observed between the untreated control and the treatments in which the antagonist had been applied in three or four consecutive years. The differences remained similar until the following growing season. Bacterial composition after repeated antagonist applications was associated with lower common scab severity. The antagonist applications had no or only slight effect on the number or abundance of OTUs belonging to Actinobacteria or Streptomyces, and no differences in quantities of pathogenic Streptomyces populations were detected by qPCR. This indicates that suppression of common scab by Str272 may not be based on direct effect on the common scab pathogens but is more likely to be associated with the alterations of the soil bacterial community. The most abundant bacteria phyla in the potato tuberosphere were Actinobacteria, Proteobacteria and Acidobacteria. However, the OTUs responding greatest to the antagonist treatments belonged to Bacterioidetes and Gemmatimonadetes. Results indicate that repeated applications of Str272 can change the bacterial community in the potato tuberosphere and lead to development of soil that is suppressive against potato common scab for several growing seasons after the last application.Peer reviewe

    Effect of hydrochlorothiazide on serum uric acid concentration : a genome-wide association study

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    Aim: To recognize genetic associations of hydrochlorothiazide-induced change in serum uric acid (SUA) concentration. Patients & methods: We conducted a genome-wide association study on hydrochlorothiazide-induced change in SUA in 214 Finnish men from the GENRES study. Replication analyses were performed in 465 Finns from the LIFE study. Results: In GENRES, we identified 31 loci associated with hydrochlorothiazide-induced change in SUA at p <5 x 10(-5). rs1002976 near VEGFC associated with the change in GENRES and in LIFE. rs950569 near BRINP3 associated with the change in SUA in GENRES and LIFE. The analysis of previously reported SNPs and candidate genes provided some proof for PADI4 and ABCC4. Conclusion: We report genetic markers that may predict the increase in SUA concentration during thiazide treatment.Peer reviewe

    Performance and flow dynamics studies of polymeric optofluidic sers sensors

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    We present a polymer-based optofluidic surface enhanced Raman scattering chip for biomolecule detection, serving as a disposable sensorchoice with cost-effective production. The SERS substrate is fabricated by using industrial roll-to-roll UV-nanoimprinting equipment andintegrated with adhesive-based polymeric microfluidics. The functioning of the SERS detection on-chip is confirmed and the effect of thepolymer lid on the obtainable Raman spectra is analysed. Rhodamine 6G is used as a model analyte to demonstrate continuous flowmeasurements on a planar SERS substrate in a microchannel. The relation between the temporal response of the sensors and sample flowdynamics is studied with varied flow velocities, using SERS and fluorescence detection. The response time of the surface-dependent SERSsignal is longer than the response time of the fluorescence signal of the bulk flow. This observation revealed the effect of convection on thetemporal SERS responses at 25 μl/min to 1000 μl/min flow velocities. The diffusion of analyte molecules from the bulk concentration intothe sensing surface induces about a 40-second lag time in the SERS detection. This lag time, and its rising trend with slower flow velocities, has to be taken into account in future trials of the optofluidic SERS sensor, with active analyte binding on the sensing surface

    Tannins, flavonoids and stilbenes in extracts of African savanna woodland trees Terminalia brownii, Terminalia laxiflora and Anogeissus leiocarpus showing promising antibacterial potential

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    Terminalia laxiflora, Terminalia brownii and Anogeissus leiocarpus are used as decoctions, macerations, infusions and fumigations in East and West African traditional medicine for treatment of infectious diseases and their symptoms. Using this ethnopharmacological information as a guideline for our research and owing to the fact that these species have not been subjected to in depth antibacterial and phytochemical studies, thirty-nine extracts of various polarities of the stem bark, stem wood and roots were studied for growth inhibitory effects against the human pathogenic bacteria Staphylococcus epidermidis, Staphylococcus aureus, Micrococcus luteus and Pseudomonas aeruginosa. Our results indicate that the studied species contain antibacterial compounds of a wide range of polarities. All polar root extracts of T. laxiflora and various polar extracts of T. brownii roots, including hot water decoctions, gave broad-spectrum antibacterial effects and low MIC values of 39 mu g/ml. The main ellagitannins in an ethyl acetate extract of the root of T. laxiflora were found to be corilagin and its derivative and punicalagin. A methanol extract of the roots of T. brownii contained methyl-(S)-flavogallonate and its derivative as the main identified ellagitannins. Moreover, both Terminalia species were found to contain ellagic acid xylopyranoside and methyl ellagic acid xyloside and pure ellagic acid was present in T. brownii. Pure punicalagin did not give as low MIC as an ethyl acetate extract of the roots of T. laxiflora, containing punicalagin as one of its main compounds, although this ellagitannin totally inhibited the growth of S. aureus at 125 mu g/ml and P. aeruginosa at 500 mu g/ml. Similarly, pure ellagic and gallic acid gave higher MIC values than the methanolic root extract of T. brownii against S. aureus and P. aeruginosa. Moreover, a Sephadex LH-20 fraction of the methanolic extract of the roots of T. brownii, enrichedwithmethyl-(S)-flavogallonate and its isomer, gave higher MIC values than the crude methanolic extract. These results suggest that the polyphenols in the extracts might act synergistically with each other. A methanolic soxhlet extract of the roots of A. leiocarpus, containing ampelopsin, aromadendrin, taxifolin, pinosylvin and 4'-methylpinosylvin gave a low MIC value of 39 mu g/ml against all bacterial strains used in this investigation. Our results demonstrate that the roots, stem bark and stem wood of T. brownii, T. laxiflora and A. leiocarpus are rich sources of (new) antimicrobial compounds and justify the uses of these plants for treatment of infections in African traditional medicine.Peer reviewe

    Lake eutrophication and brownification downgrade availability and transfer of essential fatty acids for human consumption

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    Fish are an important source of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) for birds, mammals and humans. In aquatic food webs, these highly unsaturated fatty acids (HUFA) are essential for many physiological processes and mainly synthetized by distinct phytoplankton taxa. Consumers at different trophic levels obtain essential fatty acids from their diet because they cannot produce these sufficiently de novo. Here, we evaluated how the increase in phosphorus concentration (eutrophication) or terrestrial organic matter inputs (brownification) change EPA and DHA content in the phytoplankton. Then, we evaluated whether these changes can be seen in the EPA and DHA content of piscivorous European perch (Perca fluviatilis), which is a widely distributed species and commonly consumed by humans. Data from 713 lakes showed statistically significant differences in the abundance of EPA- and DHA-synthesizing phytoplankton as well as in the concentrations and content of these essential fatty acids among oligo-mesotrophic, eutrophic and dystrophic lakes. The EPA and DHA content of phytoplankton biomass (mg HUFA g(-1)) was significantly lower in the eutrophic lakes than in the oligo-mesotrophic or dystrophic lakes. We found a strong significant correlation between the DHA content in the muscle of piscivorous perch and phytoplankton DHA content (r = 0.85) as well with the contribution of DHA-synthesizing phytoplankton taxa (r = 0.83). Among all DHA-synthesizing phytoplankton this correlation was the strongest with the dinoflagellates (r = 0.74) and chrysophytes (r = 0.70). Accordingly, the EPA + DHA content of perch muscle decreased with increasing total phosphorus (r(2) = 0.80) and dissolved organic carbon concentration (r(2) = 0.83) in the lakes. Our results suggest that although eutrophication generally increase biomass production across different trophic levels, the high proportion of low-quality primary producers reduce EPA and DHA content in the food web up to predatory fish. Ultimately, it seems that lake eutrophication and brownification decrease the nutritional quality of fish for human consumers. (C) 2016 The Authors. Published by Elsevier Ltd.Peer reviewe
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