170 research outputs found

    Procjena kvalitete i upravljanje onečišćenim sedimentima: potrebna kakvoća podataka – od molekularne razine do razine riječnih bazena

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    Management of environmental risks in river basins needs to address quality aspects of sediment – both because of its storage capacity for contaminants and due to its potential function as a secondary source of pollution. Assessment of sediment quality, however, is still prone to a number of uncertainties and insufficient information with regard to regulation, analytical methods, risk assessment and risk management. The European Water Framework Directive (WFD), e.g., has not come up with environmental quality standards for sediments. Lack of harmonization, representativeness and traceability of sediment data, not fully understood processes governing bioavailability of sediment-bound contaminants, all add up to the uncertainty that needs to be quantified. This paper details uncertainties ranging from the molecular to the basin scale level with regard to sediment quality assessment and its integration into management approaches, and it suggests ways of how to cope with a lack of data and insecure data while still developing an overview of basin wide risks.Upravljanje rizicima po okoliš u riječnim bazenima treba sadržavati i aspekt kvalitete sedimenata – zbog njihovog kapaciteta za pohranu onečišćivala, ali i zbog njihove potencijalne uloge kao sekundarnog izvora zagađenja. Međutim, procjena kvalitete sedimenata ograničena je nekim nepoznanicama i nedovoljnim brojem podataka koji se odnose na propise, analitičke metode, procjenu rizika i njegovo upravljanje. Europska direktiva za vode (European Water Framework Directive – WFD) nije još uvijek donijela standard za okolišnu kakvoću sedimenata. Nedostatak harmonizacije, reprezentativnosti i dostupnosti podataka za sedimente, kao i nedovoljno poznati procesi koji upravljaju biološkom dostupnošću onečišćivala sadržanih u sedimentu doprinose stupnju neizvjesnosti koji je potrebno kvantificirati. U radu su opisane neizvjesnosti, u rasponu od molekularne razine do razine riječnih bazena, s obzirom na postupak procjene kvalitete sedimenata i integriranje tog postupka u upravljačke sustave, uz predlaganje načina kako se usprkos nedostatku podataka ili njihovoj upitnosti mogu primijeniti metodologije procjene rizika na razini riječnih bazen

    Eine Wochenstube der Kleinen Hufeisennase, Rhinolophus hipposideros, und weitere Nachweise aus dem Eichsfeld

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    Active Fluid Borne Noise Reduction for Aviation Hydraulic Pumps

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    The aviation environment holds challenging application constraints for efficient hydraulic system noise reduction devices. Besides strong limits on component weight and size, high safety and reliability standards demand simple solutions. Hence, basic silencers like inline expansion chambers and Helmholtz-Resonators are state-of-the-art aboard commercial aircrafts. Unfortunately, they do not meet today’s noise attenuation aims regarding passenger comfort and equipment durability. Significant attenuation performance is expected from active concepts that generate anti-phase noise. However, such concepts remain a long term approach unless related costs, e.g. due to additional power allocation and real-time control equipment can be avoided. In this paper an active fluid borne noise attenuation concept is discussed that accounts for the mentioned constraints. An aircraft hydraulic pump is considered as main noise source. The active attenuator is an in-house rotary valve design. The basic feature is a known direct shaft coupling principle of pump and rotary valve, so no speed/ frequency control of the valve and no separate power supply are required. The common-shaft principle is further simplified here and proposed as integral feature of future “smart pumps”

    Hochschul- und Fachschulabsolventen: Parlamentsstudie ; Zusatzbericht

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    Im Rahmen dieser im Mai/Juni 1975 durchgeführten Parlamentsstudie wurden 806 Absolventen von Hoch- und Fachschulen erfaßt. Zum Vergleich wurden Studenten und junge Arbeiter herangezogen. Folgende Fragen wurden thematisiert: (1) ideologische Einstellungen; (2) Weltanschauung; (3) Lebensziele; (4) Zufriedenheit mit der Lebenssituation; (5) soziale Situation; (6) FDJ und gesellschaftliche Aktivität; (7) berufliche Tätigkeit. Die auch tabellarisch dargestellten Ergebnisse belegen, "daß der größte Teil der Absolventen die Grundwerte der sozialistischen Gesellschaft teilt". Jedoch kommt es beim Übergang zum Berufsleben häufig zu einer "vorübergehenden Labilisierung von Einstellungen". Ursachen hierfür können ein relativ schlechtes Einkommen, fehlender eigener Wohnraum sowie Schwierigkeiten bei der Integration im Betrieb sein. Kritisiert wird der mangelnde Praxisbezug des Studiums. "Die meisten Absolventen sind nach einiger Zeit der Berufspraxis mit den wesentlichen hochwertigen Konsumgütern ausgerüstet." (psz

    Protocol TOP-Study (tacrolimus organ perfusion): a prospective randomized multicenter trial to reduce ischemia reperfusion injury in transplantation of marginal liver grafts with an "ex vivo" tacrolimus perfusion

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    Background: Critical organ shortage results in the utilization of extended donor criteria (EDC) liver grafts. These marginal liver grafts are prone to increased ischemia reperfusion injury (IRI) which may contribute to deteriorated graft function and survival. Experimental data have shown that the calcineurin inhibitor tacrolimus exerts protective effects on hepatic IRI when applied intravenously or directly as a hepatic rinse. Therefore, the aim of the present study is to examine the effects of an ex vivo tacrolimus perfusion on IRI in transplantation of EDC liver grafts. Methods/Design: The TOP-Study (tacrolimus organ perfusion) is a randomized multicenter trial comparing the ex vivo tacrolimus perfusion of marginal liver grafts with placebo. We hypothesize that a tacrolimus rinse reduces IRI, potentially improving organ survival following transplantation of EDC livers. The study includes livers with two or more EDC, according to Eurotransplant International Foundation’s definition of EDC livers. Prior to implantation, livers randomized to the treatment group are rinsed with tacrolimus at a concentration of 20 ng/ml in 1000 ml Custodiol solution and in the placebo group with Custodiol alone. The primary endpoint is the maximum serum alanine transamninase (ALT) level within the first 48 hours after surgery; however, the study design also includes a 1-year observation period following transplantation. The TOP-Study is an investigator-initiated trial sponsored by the University of Munich Hospital. Seven other German transplant centers are participating (Berlin, Frankfurt, Heidelberg, Mainz, Münster, Regensburg, Tübingen) and aim to include a total of 86 patients. Discussion: Tacrolimus organ perfusion represents a promising strategy to reduce hepatic IRI following the transplantation of marginal liver grafts. This treatment may help to improve the function of EDC grafts and therefore safely expand the donor pool in light of critical organ shortage. Trial register: EudraCT number: 2010-021333-31, ClinicalTrials.gov identifier: NCT0156409

    Attentional Capture and Inhibition of Saccades after Irrelevant and Relevant Cues

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    Attentional capture is usually stronger for task-relevant than irrelevant stimuli, whereas irrelevant stimuli can trigger equal or even stronger amounts of inhibition than relevant stimuli. Capture and inhibition, however, are typically assessed in separate trials, leaving it open whether or not inhibition of irrelevant stimuli is a consequence of preceding attentional capture by the same stimuli or whether inhibition is the only response to these stimuli. Here, we tested the relationship between capture and inhibition in a setup allowing for estimates of the capture and inhibition based on the very same trials. We recorded saccadic inhibition after relevant and irrelevant stimuli. At the same time, we recorded the N2pc, an event-related potential, reflecting initial capture of attention. We found attentional capture not only for, relevant but importantly also for irrelevant stimuli, although the N2pc was stronger for relevant than irrelevant stimuli. In addition, inhibition of saccades was the same for relevant and irrelevant stimuli. We conclude with a discussion of the mechanisms that are responsible for these effects

    Position paper on the use of mandibular advancement devices in adults with sleep-related breathing disorders: A position paper of the German Society of Dental Sleep Medicine (Deutsche Gesellschaft Zahnaerztliche Schlafmedizin, DGZS)

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    Custom-made mandibular advancement devices are an effective treatment option for snoring, upper airway resistance syndrome, and obstructive sleep apnea (OSA). Evidence-based data indicates their efficacy, and international sleep societies recommend oral appliance (OA) therapy for patients with sleep-related breathing disorders. The following position paper by the German Society of Dental Sleep Medicine (DGZS) is to guide the interdisciplinary team (sleep physician and sleep disorder dentist) in detail when to prescribe oral appliances. This position paper supports the responsible use of OA as an effective treatment option for patients with sleep-related breathing disorders. The paper advises of proper indication regarding OSA severity, body mass index (BMI), and dentition. It emphasizes the interdisciplinary approach of oral appliance therapy and suggests treatment under the guidance of dentists trained in dental sleep medicine

    CoScience : gemeinsam forschen und publizieren mit dem Netz

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    Der Arbeitsalltag von Wissenschaftlerinnen und Wissenschaftlern hat sich in den letzten Jahren dramatisch verändert. Forschen, Schreiben und Publizieren sind mittlerweile stark durch netzbasierte Anwendungen geprägt. Das digitale Zeitalter aber hat nicht nur neue technische Werkzeuge hervorgebracht, sondern auch neue Wege eröffnet, um Wissen zu generieren und zu verbreiten. Dies gilt sowohl innerhalb der akademischen Welt als auch über diese hinaus. Das Arbeiten mit dem Netz stellt unsere bisherigen etablierten wissenschaftlichen Praktiken in Frage. Forschung wird zunehmend vernetzt, kollaborativ, multimedial, trans- bzw. interdisziplinär durchgeführt. Das vorliegende Handbuch beschreibt diese sich herausbildenden wissenschaftlichen Praktiken. Ziel der Autoren war es dabei, ein praxisnahes und leicht verständliches Handbuch zu schreiben

    The H50Q mutation induces a 10-fold decrease in the solubility of α-synuclein.

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    The conversion of α-synuclein from its intrinsically disordered monomeric state into the fibrillar cross-β aggregates characteristically present in Lewy bodies is largely unknown. The investigation of α-synuclein variants causative of familial forms of Parkinson disease can provide unique insights into the conditions that promote or inhibit aggregate formation. It has been shown recently that a newly identified pathogenic mutation of α-synuclein, H50Q, aggregates faster than the wild-type. We investigate here its aggregation propensity by using a sequence-based prediction algorithm, NMR chemical shift analysis of secondary structure populations in the monomeric state, and determination of thermodynamic stability of the fibrils. Our data show that the H50Q mutation induces only a small increment in polyproline II structure around the site of the mutation and a slight increase in the overall aggregation propensity. We also find, however, that the H50Q mutation strongly stabilizes α-synuclein fibrils by 5.0 ± 1.0 kJ mol(-1), thus increasing the supersaturation of monomeric α-synuclein within the cell, and strongly favors its aggregation process. We further show that wild-type α-synuclein can decelerate the aggregation kinetics of the H50Q variant in a dose-dependent manner when coaggregating with it. These last findings suggest that the precise balance of α-synuclein synthesized from the wild-type and mutant alleles may influence the natural history and heterogeneous clinical phenotype of Parkinson disease
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