39 research outputs found
Natuurgebieden in Europa: bescherming en financiering
In dit werkdocument is informatie verzameld over de bescherming van Europese natuurgebieden (Natura 2000-gebieden en overige beschermde gebieden) en over enkele Europese fondsen, die voor gebiedsbescherming worden gebruikt. Deze informatie is verzameld om inzicht te krijgen in de mate waarin de gebieden beschermd zijn tegen ongewenste veranderingen in landgebruik. Door bestaande indelingen voor gebiedsbescherming (Natura 2000 en IUCN) te combineren met de informatie over de Europese financiële middelen voor deze gebieden wordt een nieuwe indeling van beschermde gebieden gemaakt. Deze indeling zou, na nadere toetsing, gebruikt kunnen worden in modellen als EUruralis ten behoeve van scenario-ontwikkeling op Europees en NUTS 2-niveau
Using maximal systolic acceleration to diagnose and assess the severity of peripheral artery disease in a flow model study
Background: Because of the presence of medial calcific sclerosis, both ankle-branchial index and toe pressure measures can yield misleading results when attempting to diagnose peripheral artery disease (PAD). A new ultrasound parameter, maximal systolic acceleration (ACC(max)), can be an accurate tool for diagnosing PAD, including in diabetic patients. However, it has not been evaluated thoroughly. The aim of this study was to assess the feasibility of using ACC(max) to diagnose and assess the severity of PAD.Methods: The human circulatory system was simulated using an in vitro circulatory system driven by a pulsatile pneumatic pump. Arterial stenosis of various degrees (50%, 70%, 80%, and 90%) was simulated in order to investigate the change in several ultrasound parameters (including ACC(max)), as well as the intraluminal mean arterial pressure gradient. In a separate set of measurements, interobserver variability was measured using two investigators who were unaware of the degree of stenosis.Results: ACC(max) significantly decreased (P < .001), and the pressure gradient increased (P < .001) as the degree of stenosis increased. Moreover, we found a strong correlation between ACC(max) and the pressure gradient (R-2 = 0.937). Finally, interobserver variability with respect to ACC(max) was extremely low, with an intraclass correlation coefficient of 0.99.Conclusions: The results of this flow model study suggest that ACC(max) can be a valid, noninvasive tool for diagnosing PAD. Moreover, our finding that ACC(max) decreases as the severity of stenosis increases, together with the strong correlation between ACC(max) and the pressure gradient, suggests that ACC(max) may be useful as an alternative diagnostic tool for assessing the severity of PAD. These promising in vitro data warrant further study in a clinical setting.Vascular Surger
Differential Costs of Two Distinct Resistance Mechanisms Induced by Different Herbivore Species in Arabidopsis
Differential costs of two distinct resistance mechanisms induced by different herbivore species in Arabidopsis
Plants respond to herbivory with the induction of resistance, mediated by distinct phytohormonal signaling pathways and their interactions. Phloem feeders are known to induce plant resistance via the salicylic acid pathway, whereas biting-chewing herbivores induce plant resistance mainly via the jasmonate pathway. Here, we show that a specialist caterpillar (biting-chewing herbivore) and a specialist aphid (phloem feeder) differentially induce resistance against Pieris brassicae caterpillars in Arabidopsis (Arabidopsis thaliana) plants. Caterpillar feeding induces resistance through the jasmonate signaling pathway that is associated with the induction of kaempferol 3,7-dirhamnoside, whereas aphid feeding induces resistance via a novel mechanism involving sinapoyl malate. The role of sinapoyl malate is confirmed through the use of a mutant compromised in the biosynthesis of this compound. Caterpillar-induced resistance is associated with a lower cost in terms of plant growth reduction than aphid-induced resistance. A strong constitutive resistance againstP. brassicaecaterpillars in combination with a strong growth attenuation in plants of a transfer DNA (T-DNA) insertion mutant of WRKY70 (wrky70) suggest that the WRKY70 transcription factor, a regulator of downstream responses mediated by jasmonate-salicylic acid signaling cross talk, is involved in the negative regulation of caterpillar resistance and in the tradeoff between growth and defense. In conclusion, different mechanisms of herbivore-induced resistance come with different costs, and a functional WRKY70 transcription factor is required for the induction of low-cost resistance.</p
Modulation of flavonoid metabolites in Arabidopsis thaliana through overexpression of the MYB75 transcription factor: role of kaempferol-3,7-dirhamnoside in resistance to the specialist insect herbivore Pieris brassicae
Natuurgebieden in Europa: bescherming en financiering
In dit werkdocument is informatie verzameld over de bescherming van Europese natuurgebieden (Natura 2000-gebieden en overige beschermde gebieden) en over enkele Europese fondsen, die voor gebiedsbescherming worden gebruikt. Deze informatie is verzameld om inzicht te krijgen in de mate waarin de gebieden beschermd zijn tegen ongewenste veranderingen in landgebruik. Door bestaande indelingen voor gebiedsbescherming (Natura 2000 en IUCN) te combineren met de informatie over de Europese financiële middelen voor deze gebieden wordt een nieuwe indeling van beschermde gebieden gemaakt. Deze indeling zou, na nadere toetsing, gebruikt kunnen worden in modellen als EUruralis ten behoeve van scenario-ontwikkeling op Europees en NUTS 2-niveau
Modulation of flavonoid metabolites in Arabidopsis thaliana through overexpression of the MYB75 transcription factor: role of kaempferol-3,7-dirhamnoside in resistance to the specialist insect herbivore Pieris brassicae
Anthocyanins and flavonols are secondary metabolites that can function in plant defence against herbivores. In Arabidopsis thaliana, anthocyanin and flavonol biosynthesis are regulated by MYB transcription factors. Overexpression of MYB75 (oxMYB75) in Arabidopsis results in increasing anthocyanin and flavonol levels which enhances plant resistance to generalist caterpillars. However, how these metabolites affect specialist herbivores has remained unknown. Performance of a specialist aphid (Brevicoryne brassicae) was unaffected after feeding on oxMYB75 plants, whereas a specialist caterpillar (Pieris brassicae) gained significantly higher body mass when feeding on this plant. An increase in anthocyanin and total flavonol glycoside levels correlated negatively with the body mass of caterpillars fed on oxMYB75 plants. However, a significant reduction of kaempferol-3,7-dirhamnoside (KRR) corresponded to an increased susceptibility of oxMYB75 plants to caterpillar feeding. Pieris brassicae caterpillars also grew less on an artificial diet containing KRR or on oxMYB75 plants that were exogenously treated with KRR, supporting KRR's function in direct defence against this specialist caterpillar. The results show that enhancing the activity of the anthocyanin pathway in oxMYB75 plants results in re-channelling of quercetin/kaempferol metabolites which has a negative effect on the accumulation of KRR, a novel defensive metabolite against a specialist caterpillar
The experience of non-conveyance following emergency medical service triage from the perspective of patients and their relatives: A qualitative study
Doppler Ultrasonography Derived Maximal Systolic Acceleration: Value Determination With Artificially Induced Stenosis
Background In diagnosing peripheral arterial disease (PAD), medial arterial calcification (MAC) hampers arterial compression and could lead to unreliable ankle brachial index (ABI), toe brachial index (TBI) and toe pressure (TP). Doppler ultrasonography (DUS) derived maximal systolic acceleration (ACCmax) might be more accurate to diagnose PAD. In an in vitro study, a strong correlation between ACCmax and the severity of stenotic disease was determined. The aim of this study was to investigate the ACCmax in correlation with conventional non-invasive diagnostics in an in vivo setting. Methods: In twelve healthy individuals, an arterial stenosis was mimicked by compression on the common femoral artery by an ultrasounds probe, creating a local stenosis of 50%, 70% and 90%. The ABI, TBI, TP and several DUS parameters (including ACCmax) were assessed at the ankle during these different degrees of stenosis. All DUS parameters were measured separately by two observers to determine the interobserver variability. Results: Overall the ABI, TBI, TP, ACCmax, ACCsys and PSV decreased significantly when the degree of stenosis increased. The ACCmax showed the highest correlation with the degree of stenosis (r -.884), compared to ABI (r -.726), TBI (r -.716) and TP (r -.758). Furthermore, the interobserver variability of ACCmax was excellent, with an intraclass correlation coefficient (ICC) of .97. Conclusion: ACCmax is an accurate non-invasive DUS parameter to diagnose and assess the severity of a mimicked arterial stenosis in healthy individuals. Further prospective assessment of the clinical value of ACCmax and its potential benefits in patients with PAD is needed.Vascular Surger