Atmosphärische Stickstoffeinträge in Hochmoore Nordwestdeutschlands und Möglichkeiten ihrer Reduzierung: Eine Fallstudie aus einer landwirtschaftlich intensiv genutzten Region

Der im deutsch-niederländischen Grenzgebiet liegende 'Internationale Naturpark Bourtanger Moor/Bargerveen' zeichnet sich durch zahlreiche noch verbliebene Moore aus, deren Lage inmitten einer landwirtschaftlich intensiv genutzten Region aufgrund der erhöhten Stickstoff (N)-Deposition aus der Atmosphäre eine zusätzliche Belastung für die durch Torfabbau und Wassermangel z.T. bereits stark degradierten Moorgebiete bildet. Aus den sehr unterschiedlichen Nutzungsansprüchen in dieser Region ergeben sich unvermeidliche Konflikte zwischen Landwirtschaft und Naturschutz, die in dieser Studie aufgegriffen wurden. Gemessene Jahresmittelwerte der Ammoniak (NH3)-Konzentrationen auf den Hochmoorflächen von 3,9 bis 5,6 μg m-3 lagen auf dem Niveau landwirtschaftlich intensiv genutzter Räume. Eine effektive abschirmende Wirkung haben die an und in den Mooren vorkommenden Gehölzreihen mit einer Minderungswirkung von 14-18 %. Mit insgesamt sechs weitgehend unabhängigen Verfahren wurden N-Depositionen von 21 bis 25 kg ha-1 a-1 ermittelt. Damit sind die Critical Loads, welche für die untersuchten Hochmoortypen bei etwa 5 bis 10 kg ha-1 a-1 liegen, deutlich überschritten. Die innerhalb des Untersuchungsgebietes freigesetzten NH3-Emissionen tragen zu einem Anteil von 23 % zur Stickstoffbelastung bei, etwa 7 % stammen aus deutschen und 1 % aus niederländischen Ställen. Mit 13 % wird der größte Beitrag durch die Ausbringung von Wirtschaftsdüngern (Gülle) und Gärsubstraten von deutschen landwirtschaftlichen Flächen freigesetzt. Deutlich geringer ist der niederländische Anteil von 1,6 %. Dies ist sowohl auf den verstärkten Einsatz emissionsmindernder Ausbringungstechniken als auch auf den deutlich niedrigeren Flächenanteil im Untersuchungsgebiet zurückzuführen. 77 % der N-Depositionen gelangen über den Ferntransport in die Moore des Untersuchungsgebietes. Auch die N-Deposition über Ferntransport stammte überwiegend aus NH3-Emissionen der Landwirtschaft. In einem Szenario wurde unter Berücksichtigung aller technischen Möglichkeiten (teilweise zurzeit nur in den Niederlanden gebräuchlicher Verfahren) zur Abluftreinigung und Gülleausbringung eine maximale Minderung der NH3-Emissionen im Untersuchungsgebiet von 64 % berechnet. Das größte Minderungspotenzial von ca. 2 kg ha-1 a-1 Depositionsminderung besitzt die Ausbringung von Wirtschaftsdüngern mittels Injektionsverfahren. Die Ergebnisse verdeutlichen, dass regionale NH3-Minderungskonzepte alleine nicht ausreichend sind, um die untersuchten Moorgebiete vor schädlichen Stickstoffeinträgen zu schützen. Regionale Emissionsminderungskonzepte sollten daher in umfassende nationale und internationale Strategien zur Minderung der NH3-Emissionen aus der Landwirtschaft eingebunden werden.The 'International Nature Park Bourtanger Moor/Bargerveen' located at the German-Dutch border region is characterized by numerous remaining raised bogs within an intensively managed agricultural landscape and is thereby subjected to elevated nitrogen (N) deposition from the atmosphere. This situation leads to unavoidable conflicts of interest between agriculture and nature conservation, which are being investigated in this study. Measured annual means of ammonia (NH3) concentrations at the study sites were between 3.9 and 5.6 μg m-3, thus on the same level as values for arable sites. Grove lines form an effective protection against NH3 dispersion with a mitigation potential of 14-18 %. N deposition was determined by six independent methods and was found to be in a range from 21 to 25 kg ha-1 yr-1. These results show that bog-specific critical loads of 5 to 10 kg ha-1 yr-1 were clearly exceeded. NH3 emissions from the study area contribute 23 % to the overall nitrogen load that is locally deposited. 7 % and 1 % originate from German and Dutch stables, respectively. While the highest share of 13 % is released through the application of farm fertilizer (slurry) and fermented substrate from German arable land, only 1.6 % is emitted from Dutch sites mainly due to more efficient low-emission techniques and the smaller Dutch part of the study site compared to the German part. 77 % of the overall N deposition into the peatlands of the study area originates from non-local - but nevertheless agricultural - sources with the nitrogen being transported over long distances. A maximum reduction of NH3 emissions within the study area under consideration of all technical capabilities for waste air quality control and slurry application (some of them currently only used in the Netherlands) were found to be 64 %. Deposition can be reduced by ca. 2 kg ha-1 yr-1 through injection of fertilizer into the soil. The results show that regional NH3 mitigation concepts are not sufficient to protect the studied peatland sites against harmful excess nitrogen loads. Thus, regional concepts should be integrated into comprehensive national and international strategies to achieve an effective reduction of NH3 emissions from agricultural activities

On the indefinite Helmholtz equation: complex stretched absorbing boundary layers, iterative analysis, and preconditioning

This paper studies and analyzes a preconditioned Krylov solver for Helmholtz problems that are formulated with absorbing boundary layers based on complex coordinate stretching. The preconditioner problem is a Helmholtz problem where not only the coordinates in the absorbing layer have an imaginary part, but also the coordinates in the interior region. This results into a preconditioner problem that is invertible with a multigrid cycle. We give a numerical analysis based on the eigenvalues and evaluate the performance with several numerical experiments. The method is an alternative to the complex shifted Laplacian and it gives a comparable performance for the studied model problems

White Matter Lesions Are Not Related to β-Amyloid Deposition in an Autopsy-Based Study

Population-based studies have investigated the relation between β-amyloid levels in cerebrospinal fluid or plasma and white matter lesions (WMLs). However, these circulating levels of β-amyloid in cerebrospinal fluid or plasma may not reliably reflect the actual degree of amyloid present in the brain. Therefore, we investigated the relation between WMLs and β-amyloid plaques and amyloid angiopathy in brain tissue. WML on MRI or CT were rated in 28 nondemented patients whose neuroimaging was available prior to death. β-amyloid in plaques and arterioles were immunohistochemically stained and quantified in postmortem brain necropsies. WMLs were present in 43% of the total population. Both cortex and periventricular region showed no differences for β-amyloid deposition in either plaques or blood vessel walls in patients with WMLs compared to those without WMLs. Thus, our results indicate that there is no relation between the degree of WMLs and β-amyloid deposition in the brain

RT-PCR assay to detect FGFR3::TACC3 fusions in formalin-fixed, paraffin-embedded glioblastoma samples.

BACKGROUND: One targeted treatment option for isocitrate dehydrogenase ( IDH)-wild-type glioblastoma focuses on tumors with fibroblast growth factor receptor 3::transforming acidic coiled-coil-containing protein 3 ( FGFR3::TACC3) fusions. FGFR3::TACC3 fusion detection can be challenging, as targeted RNA next-generation sequencing (NGS) is not routinely performed, and immunohistochemistry is an imperfect surrogate marker. Fusion status can be determined using reverse transcription polymerase chain reaction (RT-PCR) on fresh frozen (FF) material, but sometimes only formalin-fixed, paraffin-embedded (FFPE) tissue is available. AIM: To develop an RT-PCR assay to determine FGFR3::TACC3 status in FFPE glioblastoma samples. METHODS: Twelve tissue microarrays with 353 historical glioblastoma samples were immunohistochemically stained for FGFR3. Samples with overexpression of FGFR3 ( n  = 13) were subjected to FGFR3::TACC3 RT-PCR on FFPE, using 5 primer sets for the detection of 5 common fusion variants. Fusion-negative samples were additionally analyzed with NGS ( n  = 6), FGFR3 Fluorescence In Situ Hybridization ( n  = 6), and RNA sequencing ( n  = 5). RESULTS: Using RT-PCR on FFPE material of the 13 samples with FGFR3 overexpression, we detected an FGFR3::TACC3 fusion in 7 samples, covering 3 different fusion variants. For 5 of these FF was available, and the presence of the fusion was confirmed through RT-PCR on FF. With RNA sequencing, 1 additional sample was found to harbor an FGFR3::TACC3 fusion (variant not covered by current RT-PCR for FFPE). The frequency of FGFR3::TACC3 fusion in this cohort was 9/353 (2.5%). CONCLUSIONS: RT-PCR for FGFR3::TACC3 fusions can successfully be performed on FFPE material, with a specificity of 100% and (due to limited primer sets) a sensitivity of 83.3%. This assay allows for the identification of potential targeted treatment options when only formalin-fixed tissue is available

Clinical characteristics of subsequent histologically confirmed meningiomas in long-term childhood cancer survivors:A Dutch LATER study

Background: Meningiomas are the most frequent brain tumours occurring after pediatric cranial radiotherapy (CrRT). Data on course of disease, to inform clinical management of meningiomas, are sparse. This study reports the clinical characteristics of histologically confirmed meningiomas in childhood cancer survivors (CCS) in the Netherlands.& nbsp; Methods: In total, 6015 CCS from the Dutch Long-Term Effects After Childhood Cancer (LATER) cohort were eligible, including 1551 with prior CrRT. These CCS were diagnosed with cancer ag

Time-domain cross-correlation baroreflex sensitivity: performance on the EUROBAVAR data set

Objective To test a new method (cross-correlation baroreflex sensitivity, xBRS) for the computation of time-domain baroreflex sensitivity on spontaneous blood pressure and heart interval variability using the EUROBAVAR data set. Methods We applied xBRS to the 42 records in the EUROBAVAR data set, obtained from 21 patients in the lying and standing positions. One patient had a recent heart transplant and one was diabetic with evident cardiac autonomic neuropathy. xBRS computes the correlation between beat-to-beat systolic blood pressure and R - R interval, resampled at 1 Hz, in a sliding 10 s window, with delays of 0-5 s for interval. The delay with the greatest positive correlation is selected and, when significant at P = 0.01, slope and delay are recorded as one xBRS value. Each 1 s of the recording is the start of a new computation. Non-parametric tests are used. Results With patients in the lying position, xBRS yielded a value of 12.4 ms/mmHg compared with the EUROBAVAR sequential 16.2 ms/mmHg, and for the standing positions the respective values were 6.2 and 6.7 ms/mmHg, giving lying to standing ratios of 1.96 and 2.10, respectively. xBRS yielded results for all files, with 20 values per minute on average at a lower within-patient variance. Best delays were 0, 1 and 2 s, and the delay increased by 102 ms when the patient was in the standing position. The xBRS method was successful in the patients with diabetes and the heart transplant. Conclusion The xBRS method should be considered for experimental and clinical use, because it yielded values that correlated strongly with and were close to the EUROBAVAR averages, yielded more values per minute, had lower within-patient variance and measured baroreflex dela

Cohort Profile : Cohort Hip and Cohort Knee (CHECK) study

The Cohort Hip and Cohort Knee (CHECK) study included participants with early symptomatic osteoarthritis (OA) of the hip or knee and evaluated clinical, radiographic and biochemical variables in order to establish the course, prognosis and underlying mechanisms of early symptomatic osteoarthritis. A total of 1002 participants aged 45-65 years, with symptomatic OA characterized by pain of knee and/ or hip, entered the cohort in the period October 2002 to September 2005. They were included at or within 6 months of their first visit to the general practitioner for these symptoms. An overview of measures that are included in the study can be found on the website [www.check-research.com]. On the basis of their presenting symptoms, participants were divided into two groups. Participants with mild symptoms visited the research centre at years 0, 2, 5, 8 and 10 (variable visiting group) and participants with more serious symptoms visited the research centre each year (annual visiting group). After 7 years, only 105 participants (10%) had dropped out; their baseline characteristics did not differ significantly from those of other participants. CHECK is a valuable source of information on early symptomatic OA, that allows the examination of high-quality data on clinical, radiographic and biochemical variables. The CHECK steering group welcomes collaboration with national and international colleagues. Requests for collaboration or access to data can be sent to [[email protected]]

Imaging performance in guiding response to neoadjuvant therapy according to breast cancer subtypes: A systematic literature review

Monitoring therapeutic response to neoadjuvant chemotherapy(NAC) is likely to improve NAC effectiveness in breast cancer(BC). Imaging performance seems to vary per tumour subtype(by ER and HER2 status), therefore we performed a systematic review on subtype specific imaging performance in monitoring NAC in BC. Studies examining imaging performance in predicting pathologic complete response(pCR) during NAC in BC subtypes were selected. Per study, negative- and positive predictive value, sensitivity(se) and specificity(sp), AUC and accuracy were derived. Fifteen/106 articles were included. Inter-study variability was revealed in: monitoring interval, response and pCR definitions. In ER-positive/HER2-negative BC, 181F FDG-PET/CT showed se/sp of 38%–89%/74%–100%, MRI showed se/sp of 35%–37%/87%–89%. In triple negative BC, 181F FDG-PET/CT showed se/sp of 0%–79%/95%–100%. 181F FDG-PET/CT showed in ER-positive/HER2-positive BC se/sp of 59%/80% and in ER-negative/HER2-positive 27%/88%. Evidence on imaging performance in monitoring NAC according BC subtypes is lacking. Consensus should be reached in: definitions of pCR, response and monitoring interval before starting well-designed studies

Arterial pressure transfer characteristics: effects of travel time

We investigated the quantitative contribution of all local conduit arterial, blood, and distal load properties to the pressure transfer function from brachial artery to aorta. The model was based on anatomical data, Young's modulus, wall viscosity, blood viscosity, and blood density. A three-element windkessel represented the distal arterial tree. Sensitivity analysis was performed in terms of frequency and magnitude of the peak of the transfer function and in terms of systolic, diastolic, and pulse pressure in the aorta. The root mean square error (RMSE) described the accuracy in wave-shape prediction. The percent change of these variables for a 25% alteration of each of the model parameters was calculated. Vessel length and diameter are found to be the most important parameters determining pressure transfer. Systolic and diastolic pressure changed <3% and RMSE <1.8 mmHg for a 25% change in vessel length and diameter. To investigate how arterial tapering influences the pressure transfer, a single uniform lossless tube was modeled. This simplification introduced only small errors in systolic and diastolic pressures (1% and 0%, respectively), and wave shape was less well described (RMSE, approximately 2.1 mmHg). Local (arm) vasodilation affects the transfer function little, because it has limited effect on the reflection coefficient. Since vessel length and diameter translate into travel time, this parameter can describe the transfer accurately. We suggest that with a, preferably, noninvasively measured travel time, an accurate individualized description of pressure transfer can be obtaine

Arterial pressure transfer characteristics: effects of travel time

We investigated the quantitative contribution of all local conduit arterial, blood, and distal load properties to the pressure transfer function from brachial artery to aorta. The model was based on anatomical data, Young's modulus, wall viscosity, blood viscosity, and blood density. A three-element windkessel represented the distal arterial tree. Sensitivity analysis was performed in terms of frequency and magnitude of the peak of the transfer function and in terms of systolic, diastolic, and pulse pressure in the aorta. The root mean square error (RMSE) described the accuracy in wave-shape prediction. The percent change of these variables for a 25% alteration of each of the model parameters was calculated. Vessel length and diameter are found to be the most important parameters determining pressure transfer. Systolic and diastolic pressure changed <3% and RMSE <1.8 mmHg for a 25% change in vessel length and diameter. To investigate how arterial tapering influences the pressure transfer, a single uniform lossless tube was modeled. This simplification introduced only small errors in systolic and diastolic pressures (1% and 0%, respectively), and wave shape was less well described (RMSE, approximately 2.1 mmHg). Local (arm) vasodilation affects the transfer function little, because it has limited effect on the reflection coefficient. Since vessel length and diameter translate into travel time, this parameter can describe the transfer accurately. We suggest that with a, preferably, noninvasively measured travel time, an accurate individualized description of pressure transfer can be obtained