Advancing the assessment of population stability as a protection goal in ecotoxicology

Exposure to low doses of pathogens that do not result in the host becoming infectious may ‘prime’ the immune response and increase protection to subsequent challenge. There is increasing evidence that such immune priming is a widespread and important feature of invertebrate host–pathogen interactions. Immune priming clearly has implications for individual hosts but will also have population-level implications. We present a susceptible–primed–infectious model—in contrast to the classic susceptible–infectious–recovered framework—to investigate the impacts of immune priming on pathogen persistence and population stability. We describe impacts of immune priming on the epidemiology of the disease in both constant and seasonal environments. A key result is that immune priming may act to destabilize population dynamics. In particular, when the proportion of individuals becoming primed rather than infected is high, but this priming does not confer full immunity, the population may be strongly destabilized through the generation of limit cycles. We discuss the implications of our model both in the context of invertebrate immunity and more widely.

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Untersuchung der Regelwerke für den passiven Schallschutz unter Berücksichtigung aktueller Verkehrslärmspektren – Teil 1

Lärmbekämpfung ◽

10.37544/1863-4672-2020-01-19 ◽

2020 ◽

Vol 15 (01) ◽

pp. 17-21

Author(s):

J. Weinzierl ◽

W. Wieland

Keyword(s):

Correction Term ◽

Spectral Composition ◽

Sound Insulation ◽

Assessment Procedure ◽

Noise Sources ◽

Frequency Dependent ◽

Protection Goal ◽

Passive Noise ◽

Sound Reduction ◽

Spectrum Adaptation

In den Regelwerken zum passiven Schallschutz von Umfassungsbauteilen wird das erforderliche Schalldämm-Maß der Fassade als Einzahlwert entsprechend dem Bewertungsverfahren nach DIN EN ISO 717-1 [1] ermittelt. Um die spektrale Zusammensetzung verschiedener Lärmquellen und die frequenzabhängige Schalldämmung von Fassadenbauteilen zu berücksichtigen, werden in den einschlägigen Regelwerken Korrektursummanden bzw. Spektrum-Anpassungswerte verwendet. Im folgenden Beitrag wird der Einfluss verschiedener Außenlärmspektren und frequenz- abhängiger Schalldämm-Maße auf den Innenpegel diskutiert. Insbesondere werden die Unterschiede zwischen Holz- und Massivbauweise bezüglich des Schutzziels bzw. des Innenpegels betrachtet. Die Untersuchungen zeigen, dass keine generelle Differenzierung zwischen Leicht- und Massivbauweise erforderlich ist. Für hochschalldämmende Leichtbaukonstruktionen mit einem Ctr,50–5000 < –8 dB wird jedoch ein Korrekturterm für das erforderliche Fassaden-Schalldämm-Maß zur Sicherstellung des Schutzziels vorgeschlagen.     Summary In the regulations for passive noise protection of surrounding components, the required sound reduction index of the facade is determined as a single value according to the assessment procedure according to DIN EN ISO 717-1 [1]. In order to take into account the spectral composition of different noise sources and the frequency-dependent sound insulation of facade components, correction summands or spectrum adaptation values are used in the relevant regulations. The following article discusses the influence of various outside noise spectra and frequency-dependent sound insulation measures on the inside level. In particular, the differences between wood and solid construction were considered with regard to the protection goal and the internal level. The investigations show that no general differentiation between lightweight and solid construction is necessary. For highly sound-insulating lightweight constructions with a Ctr, 50–5000 <-8 dB, however, a correction term for the required facade soundproofing dimension to ensure the protection goal is proposed.                              

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