1,185 research outputs found

    Beyond rest and quiescence (endodormancy and ecodormancy) : A novel model for quantifying plant-environment interaction in bud dormancy release

    Get PDF
    Bud dormancy of plants has traditionally been explained either by physiological growth arresting conditions in the bud or by unfavourable environmental conditions, such as non-growth-promoting low air temperatures. This conceptual dichotomy has provided the framework also for developing process-based plant phenology models. Here, we propose a novel model that in addition to covering the classical dichotomy as a special case also allows the quantification of an interaction of physiological and environmental factors. According to this plant-environment interaction suggested conceptually decades ago, rather than being unambiguous, the concept of "non-growth-promoting low air temperature" depends on the dormancy status of the plant. We parameterized the model with experimental results of growth onset for seven boreal plant species and found that based on the strength of the interaction, the species can be classified into three dormancy types, only one of which represents the traditional dichotomy. We also tested the model with four species in an independent experiment. Our study suggests that interaction of environmental and physiological factors may be involved in many such phenomena that have until now been considered simply as plant traits without any considerations of effects of the environmental factors.Peer reviewe

    Uuden yksityistielain vaikutukset tiekuntien toimintaan

    Get PDF
    Tiivistelmä. Tässä kandidaatintyössä tutkittiin uuden yksityistielain vaikutuksia tiekuntien toimintaan. Uusi yksityistielaki astui voimaan tammikuussa 2019 korvaten vanhan vuodelta 1963 olleen yksityistielain. Lakiuudistuksen myötä tiekuntien toimintaa jouduttiin muuttamaan joiltain osin. Uuden yksityistielain vaikutuksia tiekuntien toimintaan selvitettiin kirjallisuustutkimuksena vertaamalla uutta yksityistielakia vanhaan yksityistielakiin. Lisäksi muutoksia tutkittiin suorittamalla media-analyysi yksityistielakiin liittyvästä uutisoinnista ja kirjoituksista eri medioissa sekä haastattelemalla uuden yksityistielain kohderyhmään kuuluvia henkilöitä. Tämän tutkimuksen maantieteellisenä rajauksena oli Pohjois-Suomi. Suoritettujen kirjallisuustutkimuksen, media-analyysin ja haastattelujen perusteella uuden yksityistielain merkittävimmiksi vaikutuksiksi tunnistettiin muuttunut riitatilanteiden käsittelyprosessi sekä tiekuntien vastuun lisääntyminen. Yksityistielakimuutoksen myötä kunnan ja valtion yksityisteille myöntämien avustusten muuttuneet myöntökriteerit ovat aiheuttaneet erittäin paljon keskustelua eri medioissa. Tutkimuksessa havaittiin uuden yksityistielain seurauksena lakkautettujen kuntien tielautakuntien olleen tarpeellisia yksityistieasioita käsitteleviä toimijoita ja saman tapaisille organisaatioille olevan tarvetta myös uuden lain astuttua voimaan. Tämän tutkimuksen maantieteellisenä rajauksena oli Pohjois-Suomi, eivätkä tulokset edusta koko valtakunnan tasoa. Koko valtakunnan kattavaa tutkimusta uuden yksityistielain vaikutuksista tiekuntien toimintaan ei ole vielä suoritettu. Tällainen tutkimus on tärkeä, jotta uuden yksityistielain mahdolliset, vielä tunnistamattomat epäkohdat saataisiin selvitettyä. Tämän tutkimuksen tulokset voivat toimia lähtötietoina koko valtakunnan kattavan tutkimuksen toteuttamisessa

    Продукты ограниченного протеолиза: подходы к обнаружению и диагностические возможности в оценке тяжести патологии при эндогенной интоксикации

    Get PDF
    ПРОДУКТЫ ОГРАНИЧЕННОГО ПРОТЕОЛИЗАПРОТЕИНАЗО-ИНГИБИТОРНАЯ СИСТЕМАОТРАВЛЕНИЕ /ДИАГН /ОСЛЭНДОГЕННАЯ ИНТОКСИКАЦИЯ /ДИАГН /ОСЛСРЕДНЕМОЛЕКУЛЯРНАЯ ПЕПТИДНАЯ ФРАКЦИЯПАТОЛОГИЧЕСКИЕ ПРОЦЕССЫЛАБОРАТОРНЫЕ МЕТОДЫ И ПРОЦЕДУРЫБЕЛКОВО-ПЕПТИДНЫЕ КОМПОНЕНТ

    Redo ventral rectopexy : is it worthwhile?

    Get PDF
    Background Minimally invasive ventral mesh rectopexy (VMR) is a widely used surgical treatment for posterior pelvic organ prolapse; however, evidence of the utility of revisional surgery is lacking. Our aim was to assess the technical details, safety and outcomes of redo minimally invasive VMR for patients with external rectal prolapse (ERP) recurrence or relapsed symptoms of internal rectal prolapse (IRP). Methods This is a retrospective cohort study of patients with recurrent ERP or symptomatic IRP who underwent redo minimally invasive VMR between 2011 and 2016. The study was conducted at three hospitals in Finland. Data collected retrospectively included patient demographics, in addition to perioperative and short-term postoperative findings. At follow-up, all living patients were sent a questionnaire concerning postoperative disease-related symptoms and quality of life. Results A total of 43 redo minimally invasive VMR were performed during the study period. The indication for reoperation was recurrent ERP in 22 patients and relapsed symptoms of IRP in 21 patients. In most operations (62.8%), the previously used mesh was left in situ and a new one was placed. Ten (23.3%) patients experienced complications, including 2 (4.7%) mesh-related complications. The recurrence rate was 4.5% for ERP. Three patients out of 43 were reoperated on for various reasons. One patient required postoperative laparoscopic hematoma evacuation. Patients operated on for recurrent ERP seemed to benefit more from the reoperation. Conclusions Minimally invasive redo VMR appears to be a safe and effective procedure for treating posterior pelvic floor dysfunction with acceptable recurrence and reoperation rates.Peer reviewe

    ECG T-Wave Morphologic Variations Predict Ventricular Arrhythmic Risk in Low- and Moderate-Risk Populations

    Get PDF
    Background Early identification of individuals at risk of sudden cardiac death (SCD) remains a major challenge. The ECG is a simple, common test, with potential for large‐scale application. We developed and tested the predictive value of a novel index quantifying T‐wave morphologic variations with respect to a normal reference (TMV), which only requires one beat and a single‐lead ECG. Methods and Results We obtained reference T‐wave morphologies from 23 962 participants in the UK Biobank study. With Cox models, we determined the association between TMV and life‐threatening ventricular arrhythmia in an independent data set from UK Biobank study without a history of cardiovascular events (N=51 794; median follow‐up of 122 months) and SCD in patients with coronary artery disease from ARTEMIS (N=1872; median follow‐up of 60 months). In UK Biobank study, 220 (0.4%) individuals developed life‐threatening ventricular arrhythmias. TMV was significantly associated with life‐threatening ventricular arrhythmias (hazard ratio [HR] of 1.13 per SD increase [95% CI, 1.03–1.24]; P=0.009). In ARTEMIS, 34 (1.8%) individuals reached the primary end point. Patients with TMV ≥5 had an HR for SCD of 2.86 (95% CI, 1.40–5.84; P=0.004) with respect to those with TMV <5, independently from QRS duration, corrected QT interval, and left ventricular ejection fraction. TMV was not significantly associated with death from a cause other than SCD. Conclusions TMV identifies individuals at life‐threatening ventricular arrhythmia and SCD risk using a single‐beat single‐lead ECG, enabling inexpensive, quick, and safe risk assessment in large populations

    Gliadin induces neutrophil migration via engagement of the formyl peptide receptor, FPR1

    Get PDF
    Background Gliadin, the immunogenic component within gluten and trigger of celiac disease, is known to induce the production of Interleukin-8, a potent neutrophil-Activating and chemoattractant chemokine.We sought to study the involvement of neutrophils in the early immunological changes following gliadin exposure. Methods Utilizing immunofluorescence microscopy and flow cytometry, the redistribution of major tight junction protein, Zonula occludens (ZO)-1, and neutrophil recruitment were assessed in duodenal tissues of gliadin-gavaged C57BL/6 wild-Type and Lys-GFP reporter mice, respectively. Intravital microscopy with Lys-GFP mice allowed monitoring of neutrophil recruitment in response to luminal gliadin exposure in real time. In vitro chemotaxis assays were used to study murine and human neutrophil chemotaxis to gliadin, synthetic alpha-gliadin peptides and the neutrophil chemoattractant, fMet-Leu-Phe, in the presence or absence of a specific inhibitor of the fMet-Leu-Phe receptor-1 (FPR1), cyclosporine H. An irrelevant protein, zein, served as a control. Results Redistribution of ZO-1 and an influx of CD11b+Lys6G+ cells in the lamina propria of the small intestine were observed upon oral gavage of gliadin. In vivo intravital microscopy revealed a slowing down of GFP+ cells within the vessels and influx in the mucosal tissue within 2 hours after challenge. In vitro chemotaxis assays showed that gliadin strongly induced neutrophil migration, similar to fMet-Leu-Phe.We identified thirteen synthetic gliadin peptide motifs that induced cell migration. Blocking of FPR1 completely abrogated the fMet-Leu-Phe-, gliadin- and synthetic peptide-induced migration. Conclusions Gliadin possesses neutrophil chemoattractant properties similar to the classical neutrophil chemoattractant, fMet-Leu-Phe, and likewise uses FPR1 in the process. Copyright

    Wavelength-scale stationary-wave integrated Fourier-transform spectrometry

    Get PDF
    Spectrometry is a general physical-analysis approach for investigating light-matter interactions. However, the complex designs of existing spectrometers render them resistant to simplification and miniaturization, both of which are vital for applications in micro- and nanotechnology and which are now undergoing intensive research. Stationary-wave integrated Fourier-transform spectrometry (SWIFTS)-an approach based on direct intensity detection of a standing wave resulting from either reflection (as in the principle of colour photography by Gabriel Lippmann) or counterpropagative interference phenomenon-is expected to be able to overcome this drawback. Here, we present a SWIFTS-based spectrometer relying on an original optical near-field detection method in which optical nanoprobes are used to sample directly the evanescent standing wave in the waveguide. Combined with integrated optics, we report a way of reducing the volume of the spectrometer to a few hundreds of cubic wavelengths. This is the first attempt, using SWIFTS, to produce a very small integrated one-dimensional spectrometer suitable for applications where microspectrometers are essential

    LTB4 Is a Signal-Relay Molecule during Neutrophil Chemotaxis

    Get PDF
    SummaryNeutrophil recruitment to inflammation sites purportedly depends on sequential waves of chemoattractants. Current models propose that leukotriene B4 (LTB4), a secondary chemoattractant secreted by neutrophils in response to primary chemoattractants such as formyl peptides, is important in initiating the inflammation process. In this study we demonstrate that LTB4 plays a central role in neutrophil activation and migration to formyl peptides. We show that LTB4 production dramatically amplifies formyl peptide-mediated neutrophil polarization and chemotaxis by regulating specific signaling pathways acting upstream of actin polymerization and MyoII phosphorylation. Importantly, by analyzing the migration of neutrophils isolated from wild-type mice and mice lacking the formyl peptide receptor 1, we demonstrate that LTB4 acts as a signal to relay information from cell to cell over long distances. Together, our findings imply that LTB4 is a signal-relay molecule that exquisitely regulates neutrophil chemotaxis to formyl peptides, which are produced at the core of inflammation sites

    Substrate limitation of a habitat-forming genus Fucus under different water clarity scenarios in the northern Baltic Sea

    Get PDF
    Canopy-forming macroalgae living on rocky bottoms provide valuable ecosystem services but long-term eutrophication has narrowed their distribution and depth zonation in the Baltic Sea. The spatial distribution of macroalgae is shaped by many factors, such as light, salinity, nutrients and wave exposure. In addition, the lack of suitable hard substrates limits the distribution of algae in many areas. Analysing how the spatial distribution of macroalgae is modified by changes in environmental conditions is relevant for focusing management actions. To quantify the resultant distribution under various environmental and management scenarios, both current environmental conditions and substrate limitation need to be considered. We estimated the potential distribution area of bladderwrack Fucus spp. under 11 water transparency scenarios in 9 Finnish sea areas differing in morphology and eutrophication status. The prevailing averaged long-term water transparency conditions were interpreted from satellite images. Ten scenarios were calculated based on hypothetical changes in euphotic depth from −50% to +50% of the present. Species distribution modelling was used to assess the potential distribution areas of Fucus. In addition, to quantify the influence of substrate limitation, we estimated the average substrate limitation with two correction methods: (i) by using field data from underwater videos within the predicted distribution areas and (ii) by using a habitat model representing the distribution of reefs (i.e. rocky bottoms) in the study area. The decrease of euphotic depth by 50% from the present level narrowed the distribution area of Fucus by 24–53% in the Southwestern archipelago, 55–70% in the Gulf of Finland, 37–66% in the Bothnian Sea and 59–100% in Kvarken. An increase in euphotic depth significantly broadened the spatial distribution of Fucus. Decreasing share of suitable hard substrate along depth gradient however hinders broadening of the distribution area. If all areas were suitable for growth, a 50% increase in euphotic depth would expand the distribution area by 124–803%, depending on area. When only suitable substrates were taken into account, this percentage remained at 9–270%. We conclude that substrate limitation needs to be taken into account when estimating macroalgal species distribution in the marine environment. We show how this can be done also when comprehensive bottom substrate maps are not available. Our results are valuable when setting the targets for environmental management plans, and for balancing the local management measures in a cost effective manner. Highlights • Benthic light conditions affect the distribution of canopy-forming macroalgae Fucus. • Also substrate limits the distribution and zonation of Fucus. • Scenario modelling and substrate correction methods were utilised. • Sea areas differ in substrate composition which affects potential distribution area. • Substrate limitation is more pronounced in inner than in outer archipelago

    Synchronous counting and computational algorithm design

    Get PDF
    Consider a complete communication network on n nodes, each of which is a state machine with s states. In synchronous 2-counting, the nodes receive a common clock pulse and they have to agree on which pulses are “odd” and which are “even”. We require that the solution is self-stabilising (reaching the correct operation from any initial state) and it tolerates f Byzantine failures (nodes that send arbitrary misinformation). Prior algorithms are expensive to implement in hardware: they require a source of random bits or a large number of states s. We use computational techniques to construct very compact deterministic algorithms for the first non-trivial case of f = 1. While no algorithm exists for n < 4, we show that as few as 3 states are sufficient for all values n ≥ 4. We prove that the problem cannot be solved with only 2 states for n = 4, but there is a 2-state solution for all values n ≥ 6.Peer reviewe
    corecore