197,777 research outputs found
Hôtel de M. Gustave Ruhl-Hauzeur, avec la grille du jardin de Madame la Baronne Roly de Vien
No full textLiège - Boulevard d'Avroy. Hôtel de M. Gustave Ruhl-Hauzeur, avec la grille du jardin de Madame la Baronne Roly de Vien, là où est bâti l'hôtel Braconnier-TimmerhansSur l'enveloppe : "Liège - Hôtel de M. Gustave Ruhl-Hauzeur, avec la grille du jardin de Madame la Baronne Roly de Vien, là où est bâti l'hôtel Braconnier-Timmerhans Boulevard d'Avroy. Négatif G. Ruhl 1904. Phot. 236
RRS Discovery Cruise 377 & 378, 05 - 27 Jul 2012, Southampton to Southampton. Autonomous ecological surveying of the abyss: understanding mesoscale spatical heterogeneity at the Porcupine Abyssal Plain
No full textDetermining the distribution and abundance of life is challenging, especially in the deep sea where high pressure and other logistical challenges limit data availability to a tiny fraction of what is available for other systems. Most of Earth’s surface is nonetheless covered by water > 2000 m deep. Life in these abyssal regions influences the burial of carbon and nutrient cycling. Long-term research has now shown that even larger animals in the deep sea can vary in density by orders of magnitude, with concurrent changes in average body size, over periods as short as months. These variations are widely believed to be linked to climate-driven variation in the food supply to the deep sea. Similarly, biogeography studies have found that over distances approaching 100 km or more, the abundance of deep-sea life is related to surface productivity in the waters above. Thus the deep sea could be readily impacted by processes that alter surface ocean conditions like climate change, fishery activity, or ocean iron fertilisation.
While there has been an increase in the understanding of how climate and surface processes affect deep-sea communities, the ability to understand these links further is thought to be limited by sampling error from undetected habitat heterogeneity (i.e. irregular or uneven habitat distributions). Features like hills, valleys, depressions, small rock outcrops, and biogenic mounds add to habitat complexity, but links between such features and the animals that live among them are very poorly resolved in abyssal plain habitats using current methods. We proposed a new approach using the autonomous underwater vehicle (AUV) Autosub6000 to survey ecologically the Porcupine Abyssal Plain (PAP) Sustained Observatory to address a key question: Are spatial patterns in abyssal habitat features (like bathymetry, seafloor cover of phytodetrius [i.e. food availability], suspended solid concentration) related to spatial patterns in photographed life (density, dispersion, or biodiversity) at spatial scales from <1 m^2 to about 100 km^2?
Objectives
1. We created high-resolution ecological maps at scales of <1 m^2 to 100 km^2.
2. We will then test tractable hypotheses focusing on if any observed faunal distributions are linked with the spatial patterns of other fauna, habitat, food availability, or environmental conditions.
3. We will use the results to improve estimates of deep-sea biodiversity and ecosystem function of megafauna and relate the findings to factors such as food availability.
4. We will enhance UK capability in evaluating abyssal ecology and facilitate future time-series ecological research surveys.
Activities
• Crude oil spill impact experiments
• CTD rosette-based prokaryotic sampling.
• Megacoring
• Box coring
• Seabed High Resolution Imaging Platform (SHRIMP) surveys
• Autosub6000 surveys including acoustic mapping and photograph
The Role of Carrion Supply in the Abundance of Deep-Water Fish off California
No full textFew time series of deep-sea systems exist from which the factors affecting abyssal fish populations can be evaluated. Previous analysis showed an increase in grenadier abundance, in the eastern North Pacific, which lagged epibenthic megafaunal abundance, mostly echinoderms, by 9–20 months. Subsequent diet studies suggested that carrion is the grenadier's most important food. Our goal was to evaluate if changes in carrion supply might drive the temporal changes in grenadier abundance. We analyzed a unique 17 year time series of abyssal grenadier abundance and size, collected at Station M (4100 m, 220 km offshore of Pt. Conception, California), and reaffirmed the increase in abundance and also showed an increase in mean size resulting in a ~6 fold change in grenadier biomass. We compared this data with abundance estimates for surface living nekton (pacific hake and jack mackerel) eaten by the grenadiers as carrion. A significant positive correlation between Pacific hake (but not jack mackerel) and grenadiers was found. Hake seasonally migrate to the waters offshore of California to spawn. They are the most abundant nekton species in the region and the target of the largest commercial fishery off the west coast. The correlation to grenadier abundance was strongest when using hake abundance metrics from the area within 100 nmi of Station M. No significant correlation between grenadier abundance and hake biomass for the entire California current region was found. Given the results and grenadier longevity, migration is likely responsible for the results and the location of hake spawning probably is more important than the size of the spawning stock in understanding the dynamics of abyssal grenadier populations. Our results suggest that some abyssal fishes' population dynamics are controlled by the flux of large particles of carrion. Climate and fishing pressures affecting epipelagic fish stocks could readily modulate deep-sea fish dynamics
RRS James Cook Cruise 62, 24 Jul-29 Aug 2011. Porcupine Abyssal Plain – sustained observatory research
No full textScience rationale for the activities comes from the fact that during the EU Framework programme IV project BENGAL (1996 to 1999) radical changes were noted in fauna living on the abyssal seafloor (Progress in Oceanography, Billett 2001). The changes appeared to be related to changes in upper ocean productivity and the flux of organic matter to the abyss (Wigham et al., 2003). Various hypotheses have been created concerning the effect of total organic carbon input, shown by Lampitt et al (2010) to vary by an order of magnitude between years, the quality (organic geochemistry) of the organic material, and the timing (episodic or regular) of the inputs of organic matter. Large-scale changes in the abundance of the large epibenthic invertebrates by greater than two orders of magnitude, are now known to be mirrored by similar changes, but of a lower magnitude, in the protozoan meiofauna (c. 50 to 250 um in size) (Gooday et al. 2010), metazoan meiofauna (notably nematode and polychaete worms) (Kalogeropoulou et al. 2010) and macrofauna (250 to 1000 um in size) (Soto et al. 2010). The results have been brought together in a Special Volume in Deep-Sea Research II (Lampitt, Billett, and Martin 2010). The work below will help detail how deepsea ecosystems change naturally with time and space and in response to climate-change phenomena. It will be useful in predicting how deep-sea ecosystems will change under various climate change scenarios. In addition, coupled with other time series studies in the NE Pacific (e.g. Smith et al. 2009) and sampling around the Crozet Islands (Wolff et al. 2011), it will indicate how deep-sea ecosystems might change in relation to potential geo-engineering solutions for carbon sequestration by the oceans
Restitution par M. Ruhl du coffre de Cypsélus, selon les indications de Pausanias
No full textBeulé Ernest. Restitution par M. Ruhl du coffre de Cypsélus, selon les indications de Pausanias. In: Comptes rendus des séances de l'Académie des Inscriptions et Belles-Lettres, 6ᵉ année, 1862. pp. 96-97
Abundance and size distribution dynamics of abyssal epibenthic megafauna in the northeast Pacific
No full textThe importance of interannual variation in deep-sea abundances is now becoming recognized. There is, however, relatively little known about what processes dominate the observed fluctuations. The abundance and size distribution of the megabenthos have been examined here using a towed camera system at a deep-sea station in the northeast Pacific (Station M) from 1989 to 2004. This 16-year study included 52 roughly seasonal transects averaging 1.2 km in length with over 35 600 photographic frames analyzed. Mobile epibenthic megafauna at 4100 m depth have exhibited interannual scale changes in abundance from one to three orders of magnitude. Increases in abundance have now been significantly linked to decreases in mean body size, suggesting that accruals in abundance probably result from the recruitment of young individuals. Examinations of size-frequency histograms indicate several possible recruitment events. Shifts in size-frequency distributions were also used to make basic estimations of individual growth rates from 1 to 6 mm/month, depending on the taxon. Regional intensification in reproduction followed by recruitment within the study area could explain the majority of observed accruals in abundance. Although some adult migration is certainly probable in accounting for local variation in abundances, the slow movements of benthic life stages restrict regional migrations for most taxa. Negative competitive interactions and survivorship may explain the precipitous declines of some taxa. This and other studies have shown that abundances from protozoans to large benthic invertebrates and fishes all have undergone significant fluctuations in abundance at Station M over periods of weeks to years
Tracing abyssal food supply back to upper-ocean processes over a 17-year time series in the northeast Pacific
No full textDetrital aggregates episodically deposited on the seafloor represent an underestimated food source to deep-seacommunities. A 17-yr time-series study was conducted from 1990 to 2006 in the abyssal northeast Pacific (Sta. M,4100 m in depth) to evaluate the importance of this food source and its temporal relationship to water columnand surface ocean processes. Detrital aggregates appeared on the seafloor from June through December, with thehighest peaks in 1990, 1994, 2001, and 2002 reaching a maximum density of 23 m22 in fall 2001. A total of 15,816aggregates were measured, most less than 20 cm2 in area and with a mode of 9 cm2. Density of detrital aggregateswas highly correlated with particulate organic carbon (POC) flux at 600 and 50 m above the bottom (p , 0.001)with no time lag. Export flux of organic carbon from the euphotic zone was significantly correlated with aggregatedensity, lagged earlier by 1–4 months (p # 0.001). Zooplankton displacement volume was significantly correlatedwith POC flux (p 5 0.023) and with detrital aggregate density (p 5 0.028) on the seafloor when lagged earlier by#1 month. The Bakun upwelling index computed for the region around Sta. M was significantly correlated withdetrital aggregate density when lagged earlier by 2–5 months (p , 0.001). A strong correlation exists betweensurface ocean processes and abyssal food supply, including POC flux and detrital aggregates. This direct couplingthrough the entire water column must be considered in resolving the marine carbon cycle
Multiple Multi-Copper Oxidase Gene Families in Basidiomycetes – What for?
No full textGenome analyses revealed in various basidiomycetes the existence of multiple genes for blue multi-copper oxidases (MCOs). Whole genomes are now available from saprotrophs, white rot and brown rot species, plant and animal pathogens and ectomycorrhizal species. Total numbers (from 1 to 17) and types of mco genes differ between analyzed species with no easy to recognize connection of gene distribution to fungal life styles. Types of mco genes might be present in one and absent in another fungus. Distinct types of genes have been multiplied at speciation in different organisms. Phylogenetic analysis defined different subfamilies of laccases sensu stricto (specific to Agaricomycetes), classical Fe2+-oxidizing Fet3-like ferroxidases, potential ferroxidases/laccases exhibiting either one or both of these enzymatic functions, enzymes clustering with pigment MCOs and putative ascorbate oxidases. Biochemically best described are laccases sensu stricto due to their proposed roles in degradation of wood, straw and plant litter and due to the large interest in these enzymes in biotechnology. However, biological functions of laccases and other MCOs are generally little addressed. Functions in substrate degradation, symbiontic and pathogenic intercations, development, pigmentation and copper homeostasis have been put forward. Evidences for biological functions are in most instances rather circumstantial by correlations of expression. Multiple factors impede research on biological functions such as difficulties of defining suitable biological systems for molecular research, the broad and overlapping substrate spectrum multi-copper oxidases usually possess, the low existent knowledge on their natural substrates, difficulties imposed by low expression or expression of multiple enzymes, and difficulties in expressing enzymes heterologously
Balloir-tour Saint-Jacques et rempart d'Avroy
No full textLiège - Boulevard d'Avroy. Balloir - tour Saint Jacques et rempart d'Avroy. Vestiges de leurs fondations trouvés dans le jardin de feue la Baronne Roly de Vien lors de la construction de la maison de M. Braconnier-Timmerhans boulevard d'AvroySur l'enveloppe : "Liège - Balloir - tour Saint Jacques et rempart d'Avroy. 2. Vestiges de leurs fondations trouvés boulevard d'Avroy. Négatif G. Ruhl 1904. Phot. 243
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