Consulta: creatorFacets:"Volkenborn, Nils"
Registros recuperados: 3
Data/hora: 16/06/2024 17:25:34

Hyperspectral imaging of the microscale distribution and dynamics of microphytobenthos in intertidal sediments
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Chennu, Arjun; Faerber, Paul; Volkenborn, Nils; Al-najjar, Mohammad A. A.; Janssen, F; De Beer, Dirk; Polerecky, Lubos.
We describe a novel, field-deployable hyperspectral imaging system, called Hypersub, that allows noninvasive in situ mapping of the microphytobenthos (MPB) biomass distribution with a high spatial (sub-millimeter) and temporal (minutes) resolution over areas of 1 x 1 m. The biomass is derived from a log-transformed and near-infrared corrected reflectance hyperspectral index, which exhibits a linear relationship (R-2 &gt; 0.97) with the chlorophyll a (Ch1 a) concentration in the euphotic zone of the sediment and depends on the sediment grain size. Deployments of the system revealed that due to factors such as sediment topography, bioturbation, and grazing, the distribution of MPB in intertidal sediments is remarkably heterogeneous, with Ch1 a concentrations...
Tipo: Text
Ano: 2013
URL: https://archimer.ifremer.fr/doc/00176/28762/27229.pdf

Disturbance induced decoupling between host genetics and composition of the associated microbiome
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Wegner, Karl Mathias; Volkenborn, Nils; Peter, Hannes; Eiler, Alexander.
Background  Studies of oyster microbiomes have revealed that a limited number of microbes, including pathogens, can dominate microbial communities in host tissues such as gills and gut. Much of the bacterial diversity however remains underexplored and unexplained, although environmental conditions and host genetics have been implicated. We used 454 next generation 16S rRNA amplicon sequencing of individually tagged PCR reactions to explore the diversity of bacterial communities in gill tissue of the invasive Pacific oyster Crassostrea gigas stemming from genetically differentiated beds under ambient outdoor conditions and after a multifaceted disturbance treatment imposing stress on the host. Results  While the gill associated microbial communities in...
Tipo: Text
Palavras-chave: Microbiota; Population structure; Stress; Pathogen; Biological invasion; Pacific oyster; Crassostrea gigas; Vibrio; Mycoplasma.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00171/28202/26430.pdf

Exposure to solar radiation drives organismal vulnerability to climate: evidence from an intertidal limpet
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Chapperon, Coraline; Volkenborn, Nils; Clavier, Jacques; Seite, Sarah; Seabra, Rui; Lima, Fernando P.
Understanding the physiological abilities of organisms to cope with heat stress is critical for predictions of species’ distributions in response to climate change. We investigated physiological responses (respiration and heart beat rate) of the ectotherm limpet Patella vulgata to heat stress events during emersion and the role of seasonal and microclimatic acclimatization for individual thermal tolerance limits. Individuals were collected from 5 microhabitats characterized by different exposure to solar radiation in the high intertidal zone of a semi-exposed rocky shore in winter and summer of 2014. Upper thermal tolerance limits (heat coma temperatures - HCTs, and heart rate Arrhenius break temperatures - ABTs) were determined for individuals from each...
Tipo: Text
Palavras-chave: Patella vulgata; Heat stress; Acclimatization; Thermal tolerance; Microhabitat; Intertidal.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00318/42939/42447.pdf