4,508 research outputs found

    Ground motion emissions due to wind turbines: observations, acoustic coupling, and attenuation relationships

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    Emissions from wind turbines (WT) cover a wide range of infrasound and ground motions. When they are per- ceived as immissions by local residents, they can become a source of disturbance or annoyance. To mitigate such disturbances, it is necessary to better understand and, if possible, suppress WT-induced emissions. Within the project Inter- Wind we record and analyze ground motion signals in the vicinity of two wind farms on the Swabian Alb in southern Germany, simultaneously with acoustic and meteorological measurements, as well as psychological surveys done by co- operating research groups. The investigated wind farms con- sist of 3 and 16 WTs, respectively, and are located on the Alb peneplain at 700–800 m height, approximately 300 m higher than the two municipalities considered in our study. Our main aim is to better understand reasons why residents may be affected from WT immissions. Known ground motions include vibrations due to eigen-modes of the WT tower and blades, and the interaction between the passing blade and the tower, causing signals at con- stant frequencies below 12 Hz. In addition, we observe sig- nals in ground motion recordings at frequencies up to 90 Hz which are proportional to the blade-passing frequency. We can correlate these signals with acoustic recordings and esti-ate sound pressure to ground motion coupling transfer coefficients of 3–16.5 μm s−1 Pa−1. Sources for these emissions are the WT generator and possibly the gearing box. The identification of such noise sources can help to find measures to reduce disturbances in order to increase the public acceptance of WTs. Residents perceive more disturbance at the location where the wind farm is closer to the municipality (approximately 1 km). However, there is also a major railway line which produces higher vibration and infrasound signal amplitudes compared to the WTs. Along the measurement lines the decay rate of the WT- induced ground motions is determined for a damping relation proportional to 1/rb. We find frequency-dependent b values for different scenarios at our geological setting of Jurassic limestone on marl, sandstone, and Quaternary deposits. These damping relationships can be used to estimate emissions in the far field and to plan mitigation strategies

    Cacao agroforestry systems do not increase pest and disease incidence compared with monocultures under good cultural management practices

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    Pests and diseases threaten cacao production worldwide. Agroforestry systems are traditionally seen by farmers as one of the causes of increased pest and disease incidence, in contrast with full-sun monocultures. Cultural management practices - e.g. regular tree pruning, frequent pod harvest, regular removal of infested pods, weed management - have been reported to be crucial for pest and disease management. We performed two experiments for the purpose of assessing the effect of (i) different cacao production systems, and (ii) the frequency of harvest and removal of infested pods on the incidence of pests and diseases and on the cacao yield. The first experiment was performed in a long-term system comparison trial in Bolivia, where data on pest and disease incidence were recorded for three years in five production systems: two monocultures and two agroforestry system under organic and conventional farming, and one successional agroforestry system, i.e. a high tree density multi-strata system. Pest and disease management did not differ between systems and relied on cultural management practices. Overall, the incidence of pests and diseases did not differ between production systems, which indicated they were not the driver of yield differences between them. Across production systems, only 14% of the pods were affected by pests and diseases; 70% of these were affected by frosty pod rot. More than 80% of the pods infected by frosty pod rot were removed before the sporulation phase. In the second experiment, the effects of the frequency of harvest and removal of infected pods - every 15 days versus every 25 days - on pest and disease incidence and yield were tested in four farmers’ fields. Fortnightly harvest and diseased pod removal significantly decreased disease incidence and increased cacao yield, by 25% and 46% respectively. Our results show that cacao agroforestry systems do not increase pest and disease incidence compared with monocultures when good cultural management practices are implemented, which, in turn, can increase the productivity of the cacao plantations

    Creating employment or keeping them busy: an evaluation of training programs for older workers in Germany

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    "We analyze the effect of participation in short-term training measures on older German recipients of means-tested unemployment benefits. Our analysis uses administrative data of the German Federal Employment Agency and we estimate the effects of participating in two types of short-term training - classroom and in-firm training - on different outcomes of the participants. Our results show that classroom training is not effective in making participants independent of benefit receipt. It has a moderately positive effect on employment outcomes, which are highest for West German men. In contrast, in-firm training significantly raises the participants' likelihood of finding regular jobs and of being independent of unemployment benefit receipt." (author's abstract

    Report on the use of EU Reference Methods and JRC decision tools for GMO analysis

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    To ensure harmonised scientific and technical approaches for GMO detection the European Union Reference Laboratory for GM Food and Feed (EURL GMFF) at the Joint Research Centre (JRC) has developed a freely accessible database, called “GMOMETHODS" providing a state-of-the-art catalogue of EU reference methods for GMO analysis. The EURL GMFF launched in 2015 a survey to assess the use of these EU reference methods by the official GMO control laboratories in the EU and to collect information on non-EU reference methods possibly employed for the same purpose. The survey aimed also to verify if, and to which extent, laboratories use two decision supporting tools, the JRC GMO-Matrix and Event-Finder which are available on the web site of the EURL GMFF. The survey was also directed to verify the types and frequencies of modifications possibly implemented in the protocols of the validated methods used by the official control laboratories. Results from the survey indicate that almost all official control laboratories (98 %) are using event-specific EU reference methods for quantifying GMOs while a lower number of laboratories is using EU reference methods for qualitative analyses (55 % for element-specific methods and 40 % for construct-specific methods). The use of qualitative non-EU reference methods for screening purposes may reflect the laboratory needs when facing rapid alert emergencies of quickly implementing analytical strategies for detecting non-authorised GM events. Indeed genetically modified crops have continued to increase globally, both in terms of approval status and event/trait diversification. In those cases methods validated in collaborative studies and having the status of EU-reference methods are generally not yet available. In the survey close to half of the respondents (41 %-47 %) declared also to employ to different extents the two JRC decision supporting tools, GMO-Matrix and Event-Finder. Interestingly the survey shows that almost half of the protocols of the reference methods used by the laboratories are somewhat adapted to laboratory specific conditions, mainly with respect to the master mix and the reaction volume of the polymerase chain reactions (PCR) while the primers and probes are never modified. In all cases, the impact of these modifications had been verified by the control laboratory to ensure the equivalence between the adapted and the original protocols. Without such proof, the laboratory would lose its mandatory accreditation. Moreover, participants in Comparative Testing schemes have achieve generally high score performance using those adapted methods suggesting that the modifications implemented do not affect analytical sensitivity, trueness and precision of the original protocols. The outcome of the 2015 survey reveals therefore that the combined efforts of the EURL GMFF and ENGL have been successful for enhancing harmonisation in quantitative GMO analysis by the adoption of scientific and technical approaches. This achievement allows the consistency of results for GM labelling and an equal-level playing field in the EU Member States.JRC.F.5-Food and Feed Complianc

    Competencies in understanding statistical information in primary and secondary school levels: An inter-cultural empirical study with German and Colombian students

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    This paper is devoted to examining the validity of a hierarchical competency model of statistical literacy by assessing the corresponding competency levels of primary and secondary students from Colombia and Germany. The results replicate prior findings and confirm the hierarchical competency model. The study has two novel components with respect to previous work on competency levels in statistical literacy: it examines elementary school performance and it includes an intercultural comparison. The competency scores reached by the students, however, suggest specific profiles of sub-groups of learners included in the study. The intercultural study is clearly exploratory since the samples both in Colombia and in Germany were not representative. The results point to interesting new questions and motivate further intercultural research

    Brain oscillations differentially encode noxious stimulus intensity and pain intensity

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    Noxious stimuli induce physiological processes which commonly translate into pain. However, under certain conditions, pain intensity can substantially dissociate from stimulus intensity, e.g. during longer-lasting pain in chronic pain syndromes. How stimulus intensity and pain intensity are differentially represented in the human brain is, however, not yet fully understood. We therefore used electroencephalography (EEG) to investigate the cerebral representation of noxious stimulus intensity and pain intensity during 10 min of painful heat stimulation in 39 healthy human participants. Time courses of objective stimulus intensity and subjective pain ratings indicated a dissociation of both measures. EEG data showed that stimulus intensity was encoded by decreases of neuronal oscillations at alpha and beta frequencies in sensorimotor areas. In contrast, pain intensity was encoded by gamma oscillations in the medial prefrontal cortex. Contrasting right versus left hand stimulation revealed that the encoding of stimulus intensity in contralateral sensorimotor areas depended on the stimulation side. In contrast, a conjunction analysis of right and left hand stimulation revealed that the encoding of pain in the medial prefrontal cortex was independent of the side of stimulation. Thus, the translation of noxious stimulus intensity into pain is associated with a change from a spatially specific representation of stimulus intensity by alpha and beta oscillations in sensorimotor areas to a spatially independent representation of pain by gamma oscillations in brain areas related to cognitive and affective-motivational processes. These findings extend the understanding of the brain mechanisms of nociception and pain and their dissociations during longer-lasting pain as a key symptom of chronic pain syndromes

    Arbeitssuche von Migranten: Deutschkenntnisse beeinflussen Suchintensität und Suchwege

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    Migranten der zweiten Generation sprechen viel häufiger Deutsch im eigenen Haushalt als Migranten der ersten Generation. Erwerbslose Personen, die zu Hause vor allem Deutsch sprechen, suchen intensiver nach Arbeit. Deutschkenntnisse spielen auch eine Rolle dabei, wie häufig bestimmte Wege der Arbeitsuche eingeschlagen werden. Je besser die Sprachkenntnisse, desto eher lesen Arbeitsuchende Stellenanzeigen in Zeitungen und bewerben sich auf Stellenanzeigen oder sie recherchieren im Internet. Arbeitsuchende aus mehrsprachigen Haushalten können bei ihrer Arbeitsuche leichter auf soziale Netzwerke zurückgreifen. Erwerbslose Migrantinnen, die zu Hause überwiegend eine Fremdsprache sprechen, suchen viel seltener aktiv nach Arbeit als andere Erwerbslose. Soweit langzeitarbeitslose Migranten starke Defizite bei den Deutschkenntnissen aufweisen, sollte Arbeitsmarktpolitik also auch gezielt bei der Sprachförderung ansetzen, um ihre Arbeitsmarktchancen zu verbessern

    Proenkephalin, neutrophil gelatinase-associated lipocalin, and estimated glomerular filtration rates in patients with sepsis

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    Background: Proenkephalin (PENK) has been suggested as a novel biomarker for kidney function. We investigated the diagnostic and prognostic utility of plasma PENK in comparison with neutrophil gelatinase-associated lipocalin (NGAL) and estimated glomerular filtration rates (EGFR) in septic patients. Methods: A total of 167 septic patients were enrolled: 99 with sepsis, 37 with septic shock, and 31 with suspected sepsis. PENK and NGAL concentrations were measured and GFR was estimated by using the isotope dilution mass spectrometry traceable-Modification of Diet in Renal Disease (MDRD) Study and three Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations: CKD-EPICr, CDK-EPICysC, and CKD-EPICr-CysC. The PENK, NGAL, and EGFR results were compared according to sepsis severity, presence or absence of acute kidney injury (AKI), and clinical outcomes. Results: The PENK, NGAL, and EGFR results were significantly associated with sepsis severity and differed significantly between patients with and without AKI only in the sepsis group (all P<0.05). PENK was superior to NGAL in predicting AKI (P=0.022) and renal replacement therapy (RRT) (P=0.0085). Regardless of the variable GFR category by the different EGFR equations, PENK showed constant and significant associations with all EGFR equations. Unlike NGAL, PENK was not influenced by inflammation and predicted the 30-day mortality. Conclusions: PENK is a highly sensitive and objective biomarker of AKI and RRT and is useful for prognosis prediction in septic patients. With its diagnostic robustness and predictive power for survival, PENK constitutes a promising biomarker in critical care settings including sepsis

    Prefrontal gamma oscillations encode tonic pain in humans

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    Under physiological conditions, momentary pain serves vital protective functions. Ongoing pain in chronic pain states, on the other hand, is a pathological condition that causes widespread suffering and whose treatment remains unsatisfactory. The brain mechanisms of ongoing pain are largely unknown. In this study, we applied tonic painful heat stimuli of varying degree to healthy human subjects, obtained continuous pain ratings, and recorded electroencephalograms to relate ongoing pain to brain activity. Our results reveal that the subjective perception of tonic pain is selectively encoded by gamma oscillations in the medial prefrontal cortex. We further observed that the encoding of subjective pain intensity experienced by the participants differs fundamentally from that of objective stimulus intensity and from that of brief pain stimuli. These observations point to a role for gamma oscillations in the medial prefrontal cortex in ongoing, tonic pain and thereby extend current concepts of the brain mechanisms of pain to the clinically relevant state of ongoing pain. Furthermore, our approach might help to identify a brain marker of ongoing pain, which may prove useful for the diagnosis and therapy of chronic pain
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