323 research outputs found
Traditional Water Meadows: A Sustainable Management Type for the Future?
Traditional meadow irrigation techniques were once widespread throughout Europe and served as a method of grassland intensification before the era of mineral fertilization. Close to Landau (Palatinate), Germany, there are several hectares of traditionally irrigated water meadows that are irrigated twice a year in parts since the medieval age or irrigation has been reinitiated since the 1990. In a research project âWasserWiesenWerteâ, we analyzed the ecological and socio-economic value of meadow irrigation. We compared extensively to semi-intensively used meadows with fertilizer application between 0 and 80 kg N/ha per year which were either irrigated or nonirrigated. The results were very motivating. Biomass production is increased by about one-third with irrigation. At the same time, several species groups did not decrease in frequency and diversity in the meadows under irrigation. In contrast, some especially rare species seemed to even profit. Ditch structures turned out to be especially important refuges for sensible meadow species and added a large quantity of additional species to the landscape diversity. We propose that the revitalization of traditional irrigation techniques should be considered when extensively managed grasslandâespecially hay meadowsâare prone to either intensification or abandonment
Editorial: New insights into the treatment of aneurysms with flow diverters: novel indications and therapeutic advances
Historical Irrigated Meadows at the River Queich, Rhineland-Palatinate
For centuries the meadows at the river Queich in southern Rhineland-Palatinate were irrigated to enhance the quantity and quality of hay. With the introduction of fertili-zers irrigation was stopped in most areas but partly reactivated within the last few years. Today we find a small-scaled mosaic of (non-) irrigated and (un-) fertilized meadows. The Institute for Environmental Sciences Landau at the University of Koblenz - Landau conducts interdisciplinary research on the meadows to investigate the effects of irrigation and the interactions between the involved terrestrial and aquatic systems
Local adaptations to frost in marginal and central populations of the dominant forest tree Fagus sylvatica L. as affected by temperature and extreme drought in common garden experiments
Local adaptations to environmental conditions are of high ecological importance as they determine distribution ranges and likely affect species responses to climate change. Increased environmental stress (warming, extreme drought) due to climate change in combination with decreased genetic mixing due to isolation may lead to stronger local adaptations of geographically marginal than central populations. We experimentally observed local adaptations of three marginal and four central populations of Fagus sylvaticaL., the dominant native forest tree, to frost over winter and in spring (late frost). We determined frost hardiness of buds and roots by the relative electrolyte leakage in two common garden experiments. The experiment at the cold site included a continuous warming treatment; the experiment at the warm site included a preceding summer drought manipulation. In both experiments, we found evidence for local adaptation to frost, with stronger signs of local adaptation in marginal populations. Winter frost killed many of the potted individuals at the cold site, with higher survival in the warming treatment and in those populations originating from colder environments. However, we found no difference in winter frost tolerance of buds among populations, implying that bud survival was not the main cue for mortality. Bud late frost tolerance in April differed between populations at the warm site, mainly because of phenological differences in bud break. Increased spring frost tolerance of plants which had experienced drought stress in the preceding summer could also be explained by shifts in phenology. Stronger local adaptations to climate in geographically marginal than central populations imply the potential for adaptation to climate at range edges. In times of climate change, however, it needs to be tested whether locally adapted populations at range margins can successfully adapt further to changing conditions
Einfluss von BewĂ€sserung und DĂŒngung auf die organische Bodensubstanz in extensiv genutzten Heuwiesen - Thermische Eigenschaften und Evolved Gasanalyse
Wiesen beherbergen etwa 40 % der in Deutschland geschĂŒtzten Arten. Neben ihrer Funktion zur Erhaltung der BiodiversitĂ€t dienen sie als ĂberschwemmungsflĂ€chen dem Hochwasserschutz und sorgen fĂŒr eine Filterung des Grund- und OberflĂ€chenwassers. Aufgrund dieser wichtigen Funktionen wurden in der Vergangenheit viele Untersuchungen gemacht, wie sich unterschiedliche landwirtschaftliche Bewirtschaftungsformen auf die BiodiversitĂ€t von Wiesen auswirken. Um diese Prozesse besser zu verstehen ist es nötig, auch die unterirdisch ablaufenden biogeochemischen Prozesse zu berĂŒcksichtigen. Neben Bodenflora und âfauna spielen dabei auch abiotische Bodeneigenschaften wie z.B. NĂ€hrstoffgehalt und âverfĂŒgbarkeit oder WasserhaltekapazitĂ€t eine entscheidende Rolle. Der NĂ€hrstoff- und Wasserhaushalt eines Bodens hĂ€ngt wiederum stark vom Gehalt und der QualitĂ€t der organische Bodensubstanz ab. Um die Kopplung von unterirdischen biogeochemischen Prozessen mit der oberirdischen PflanzendiversitĂ€t besser zu verstehen, haben wir in einem ersten Schritt die Auswirkung von BewĂ€sserung und DĂŒngung auf ausgewĂ€hlte Eigenschaften der organischen Bodensubstanz mithilfe von Thermogravimetrie (TGA) gekoppelt mit Differential Scanning Calorimetry (DSC) und Evolved Gasanalyse mit Massenspektrometrie (EGA-MS) untersucht. Hierzu wurden 12 extensiv genutzte Heuwiesen, die sogenannten âWĂ€sserwiesenâ, entlang der Queich bei Landau (Rheinland-Pfalz) beprobt. Diese Wiesen wurden seit dem Mittelalter traditionell nach einem festgelegten BewĂ€sserungskalender zwei bis dreimal im Jahr fĂŒr ein bis drei Tage durch Ăberflutung mit dem Wasser der Queich bewĂ€ssert. Auf einigen dieser Wiesen wurde diese Form der BewĂ€sserung seit den 50iger Jahren eingestellt. Dadurch ergab sich die einmalige Möglichkeit vergleichbare Wiesen mit und seit ĂŒber 50 Jahren ohne ĂberflutungsbewĂ€sserung sowie mit und ohne anorganische DĂŒngung zu untersuchen. Im vorliegenden Beitrag werden die Ergebnisse dieser Studie vorgestellt und die Möglichkeiten und Grenzen thermischer Methoden zur Charakterisierung von organischer Bodensubstanz diskutiert
Glioma infiltration of the corpus callosum: early signs detected by DTI
The most frequent primary brain tumors, anaplastic astrocytomas (AA) and glioblastomas (GBM): tend to invasion of the surrounding brain. Histopathological studies found malignant cells in macroscopically unsuspicious brain parenchyma remote from the primary tumor, even affecting the contralateral hemisphere. In early stages, diffuse interneural infiltration with changes of the apparent diffusion coefficient (ADC) and fractional anisotropy (FA) is suspected. The purpose of this study was to investigate the value of DTI as a possible instrument of depicting evidence of tumor invasion into the corpus callosum (CC). Preoperatively, 31 patients with high-grade brain tumors (8 AA and 23 GBM) were examined by MRI at 3 T, applying a high-resolution diffusion tensor imaging (DTI) sequence. ADC- and FA-values were analyzed in the tumor-associated area of the CC as identified by fiber tracking, and were compared to matched healthy controls. In (MR-)morphologically normal appearing CC the ADC values were elevated in the tumor patients (n = 22; 0.978 Ă 10(â3) mmÂČ/s) compared to matched controls (0.917 Ă 10(â3) mmÂČ/s, p < 0.05), and the corresponding relative FA was reduced (rFA: 88 %, p < 0.01). The effect was pronounced in case of affection of the CC visible on MRI (n = 9; 0.978 Ă 10(â3) mmÂČ/s, p < 0.05; rFA: 72 %, p < 0.01). Changes in diffusivity and anisotropy in the CC can be interpreted as an indicator of tumor spread into the contralateral hemisphere not visible on conventional MRI
Neoplastic Meningitis: How MRI and CSF Cytology Are Influenced by CSF Cell Count and Tumor Type
Background. Although CSF cytology and MRI are standard methods to diagnose neoplastic meningitis (NM), this complication of neoplastic disease remains difficult to detect. We therefore reevaluated the sensitivity of gadolinium (GD)-enhanced MRI and cerebrospinal-fluid (CSF)-cytology and the relevance of tumor type and CSF cell count. Methods. We retrospectively identified 111 cases of NM diagnosed in our CSF laboratory since 1990 with complete documentation of both MRI and CSF cytology. 37 had haematological and 74 solid neoplasms. CSF cell counts were increased in 74 and normal in 37 patients. Results. In hematological neoplasms, MRI was positive in 49% and CSF cytology in 97%. In solid tumors, the sensitivity of MRI was 80% and of cytology 78%. With normal CSF cell counts, MRI was positive in 59% (50% hematological, 72% solid malignancies) and CSF cytology in 76% (92% in hematological, 68% in solid neoplasms). In cases of elevated cell counts, the sensitivity of MRI was 72% (50% for hematological, 83% for solid malignancies) and of CSF cytology 91% (100% for haematological and 85% for solid neoplasms). 91% of cytologically positive cases were diagnosed at first and another 7% at second lumbar puncture. Routine protein analyses had a low sensitivity in detecting NM. Conclusions. The high overall sensitivity of MRI was only confirmed for NM from solid tumors and for elevated CSF cell counts. With normal cell counts and haematological neoplasms, CSF-cytology was superior to MRI. None of the analysed routine CSF proteins had an acceptable sensitivity and specificity in detecting leptomeningeal disease
Evaluation of intracranial stenting in a simulated training and assessment environment for neuroendovascular procedures
PurposeGiven the inherent complexity of neurointerventional procedures and the associated risks of ionizing radiation exposure, it is crucial to prioritize ongoing training and improve safety protocols. The aim of this study is to assess a training and evaluation in-vitro environment using a vascular model of M1 stenosis, within a clinical angiography suite, without relying on animal models or X-ray radiation.Materials and methodsUsing a transparent model replicating M1 stenosis, we conducted intracranial stenting procedures with four different setups (Gateway & Wingspan, Gateway & Enterprise, Neurospeed & Acclino, and Pharos Vitesse). A video camera was integrated with the angiography systemâs monitor for real-time visualization, while a foot switch was employed to simulate live fluoroscopy. Three neuroradiologists with varying levels of expertise performed each procedure for three times. The total duration of fluoroscopy as well as the time from passing the stenosis with the wire to completion of the procedure were recorded using a dedicated software designed for this experimental setup.ResultsCompared to the Gateway & Wingspan procedure, the total fluoroscopy time reduced significantly with the Gateway & Enterprise, Neurospeed & Acclino, and Pharos Vitesse procedures by 51.56 s, 111.33 s, and 144.89 s, respectively (p < 0.001). Additionally, physicians with under 2 years and over 5 years of experience reduced FT by 62.83 s and 106.42 s, respectively, (p < 0.001), compared to a novice physician. Similar trends were noted for the time of wire distal to stenosis, with significant reductions for Neurospeed & Acclino and Pharos Vitesse compared to both Gateway & Wingspan as well as Gateway & Enterprise (all p < 0.001).ConclusionProcedures requiring wire exchange maneuvers exhibited nearly twice the fluoroscopy time in comparison to balloon-mounted stenting or stent-placement via PTA balloon catheters. The more experienced neuroradiologist demonstrated significantly quicker performance in line with expectations in a real-life clinical setting, when compared to the less experienced interventionalist. This in-vitro setup allowed the evaluation of alternative technical approaches and differences in experience of operators without the use of animal models or X-ray. The setup combines advantages of simulators and silicone vessel models in a realistic working environment
The status under EU Law of Organisms developed through novel genomic techniques
In a ruling on 25 July 2018, the Court of Justice of the European Union concluded that organisms obtained by means of techniques/methods of mutagenesis constitute GMOs in the sense of Directive 2001/18, and that organisms obtained by means of techniques/methods of directed mutagenesis are not excluded from the scope of the Directive. Following the ruling, there has been much debate about the possible wider implications of the ruling. In October 2019, the Council of the European Union requested the European Commission to submit, in light of the CJEU ruling, a study regarding the status of novel genomic techniques under Union Law. For the purpose of the study, the Commission initiated stakeholder consultations early in 2020. Those consultations focused on the technical status of novel genomic techniques.
This article aims to contribute to the discussion on the legal status of organisms developed through novel genomic techniques, by offering some historical background to the negotiations on the European Union (EU) GMO Directives as well as a technical context to some of the terms in the Directive, and by analysing the ruling. The article advances that (i) the conclusion that organisms obtained by means of techniques/methods of mutagenesis constitute GMOs under the Directive means that the resulting organisms must comply with the GMO definition, ie the genetic material of the resulting organisms has been altered in a way that does not occur naturally by mating and/or natural recombination; (ii) the conclusion that organisms obtained by means of techniques/methods of directed mutagenesis were not intended to be excluded from the scope of the Directive is not inconsistent with the negotiation history of the Directive; (iii) whether an organism falls under the description of âobtained by means of techniques/methods of directed mutagenesisâ depends on whether the genetic material of the resulting organisms has been altered in a way that does not occur naturally by mating and/or natural recombination. Finally, the article offers an analysis of the EU GMO definition, concluding that for an organism to be a GMO in the sense of the Directive, the technique used, as well as the genetic alterations of the resulting organism, must be considered
European Multicenter Study for the Evaluation of a Dual-Layer Flow-Diverting Stent for Treatment of Wide-Neck Intracranial Aneurysms: The European Flow-Redirection Intraluminal Device Study
BACKGROUND AND PURPOSE: Endoluminal reconstruction with flow-diverting stents represents a widely accepted technique for the treatment of complex intracranial aneurysms. This European registry study analyzed the initial experience of 15 neurovascular centers with the Flow-Redirection Intraluminal Device (FRED) system. MATERIALS AND METHODS: Consecutive patients with intracranial aneurysms treated with the FRED between February 2012 and March 2015 were retrospectively reviewed. Complications and adverse events, transient and permanent morbidity, mortality, and occlusion rates were evaluated. RESULTS: During the defined study period, 579 aneurysms in 531 patients (median age, 54 years;range, 13-86 years) were treated with the FRED. Seven percent of patients were treated in the acute phase (3 days) of aneurysm rupture. The median aneurysm size was 7.6 mm (range, 1-36.6 mm), and the median neck size 4.5 mm (range, 1-30 mm). Angiographic follow-up of >3 months was available for 516 (89.1%) aneurysms. There was progressive occlusion witnessed with time, with complete occlusion in 18 (20%) aneurysms followed for up to 90 14 days, 141 (82.5%) for 180 +/- 20 days, 116 (91.3%) for 1 year +/- 24 days, and 122 (95.3%) aneurysms followed for >1 year. Transient and permanent morbidity occurred in 3.2% and 0.8% of procedures, respectively. The overall mortality rate was 1.5%. CONCLUSIONS: This retrospective study in real-world patients demonstrated the safety and efficacy of the FRED for the treatment of intracranial aneurysms. In most cases, treatment with a single FRED resulted in complete angiographic occlusion at 1 year
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