ALBERT

Beschreibung: Basement heat flow is one of the key unknowns in sedimentary basin analysis. Its quantification is challenging not in the least due to the various feedback mechanisms between the basin and lithosphere processes. This study explores two main feedbacks, sediment blanketing and thinning of sediments during lithospheric stretching, in a series of synthetic models and a reconstruction case study from the Norwegian Sea. Three types of basin models are used: (1) a newly developed one-dimensional (1D) forward model, (2) a decompaction/backstripping approach and (3) the commercial basin modelling software TECMOD2D for automated forward basin reconstructions. The blanketing effect of sedimentation is reviewed and systematically studied in a suite of 1D model runs. We find that even for moderate sedimentation rates (0.5 mm year−1), basement heat flow is depressed by ∼25% with respect to the case without sedimentation; for high sedimentation rates (1.5 mm year−1), basement heat flow is depressed by ∼50%. We have further compared different methods for computing sedimentation rates from the presently observed stratigraphy. Here, we find that decompaction/backstripping-based methods may systematically underestimate sedimentation rates and total subsidence. The reason for this is that sediments are thinned during lithosphere extension in forward basin models while there are not in backstripping/decompaction approaches. The importance of sediment blanketing and differences in modelling approaches is illustrated in a reconstruction case study from the Norwegian Sea. The thermal and structural evolution of a transect across the Vøring Basin has been reconstructed using the backstripping/decompaction approach and TECMOD2D. Computed total subsidence curves differ by up to ∼3 km and differences in computed basement heat flows reach up to 50%. These findings show that strong feedbacks exist between basin and lithosphere processes and that resolving them require integrated lithosphere-scale basin models.

Beschreibung: Cephalopods are a key component of marine food webs, providing sustenance for myriad marine species. Cephalopods are also of increasing economic importance as evidenced by the rapid rise in their global landings over recent decades. If fisheries continue on this trajectory, conflicts may transpire among cephalopod and finfish fisheries, particularly in ecosystems where cephalopods are highly valuable both directly as a landed commodity and indirectly as prey for other harvested species. We provide the first measure of the ecosystem services that cephalopods contribute to fisheries in 28 marine ecosystems, both as a commodity and an ecological support service. We also evaluate how current demands on cephalopods compare to mid-20th century conditions. We find that cephalopod contributions to fisheries vary widely, but are substantial in many ecosystems. Commodity and supportive services provided by cephalopods contributed as much as 55% of fishery landings (tonnes) and 70% of landed values ($USD). The contribution of cephalopods as a commodity was generally greatest in the coastal ecosystems, whereas their contribution as a supportive service was highest in open ocean systems. Further, the commodity and supportive services provided by cephalopods to fisheries landings increased in most of the coastal ecosystems between the mid-20th century (years 1960–70) and contemporary periods (years 1990–2004), indicating the rising demand for cephalopods. Current demands have no historical precedent and ecosystems in which cephalopods are highly exploited as a targeted resource and as an ecological support service should be further evaluated to prevent the unsustainable development of marine fisheries within them.

Beschreibung: Der Tintenfisch Octopus aegina zeigt eine hochentwickelte Brutpflege. Ein bei den Nikobaren gefundenes Weibchen hütete die Eier im Schutze einer leeren Herzmuschel. Es strich mit den Armenden dauernd über die Laichschnüre und gewährte auch Schlüpfhilfe. Sich nähernde Schnecken und Krebschen wurden mit den Armen weggestoßen, mitunter sogar weggetragen und mit Tinte angespritzt. Das brutpflegende Weibchen nahm keinerlei Nahrung zu sich und starb kurz nach dem Schlüpfen der Jungen.

Beschreibung: Objectives Carotenoids and retinoic acid derivatives are topically applied for sun‐protective and whitening purposes. Fucoxanthin is a carotenoid derived from edible sea algae, but its effect on melanogenesis has not been established. Therefore, we examined the effect of fucoxanthin on melanogenesis. Methods Inhibitory effects on tyrosinase activity, melanin formation in B16 melanoma and skin pigmentation in UVB‐irradiated guinea‐pigs were evaluated. To elucidate the action of fucoxanthin on melanogenesis, its effect on skin melanogenic mRNA expression was evaluated in UVB‐irradiated mice. Fucoxanthin was given topically or orally to mice once a day and UVB irradiation was applied for 14 days. The effect of fucoxanthin on skin melanogenic mRNA expression was evaluated by real time reverse transcription polymerase chain reaction. Key findings Fucoxanthin inhibited tyrosinase activity, melanogenesis in melanoma and UVB‐induced skin pigmentation. Topical application of fucoxanthin (1%) significantly suppressed mRNA expression of cyclooxygenase (COX)‐2, endothelin receptor A, p75 neurotrophin receptor (NTR), prostaglandin E receptor 1 (EP1), melanocortin 1 receptor (MC1R) and tyrosinase‐related protein 1. The suppression of p75NTR, EP1 and MC1R expressions was observed at 0.01% application. Also, oral application of fucoxanthin (10 mg/kg) significantly suppressed expression of COX‐2, p75NTR, EP1 and MC1R. Conclusions These results suggest that fucoxanthin exhibits anti‐pigmentary activity by topical or oral application in UVB‐induced melanogenesis. This effect of fucoxanthin may be due to suppression of prostaglandin (PG) E2 synthesis and melanogenic stimulant receptors (neurotrophin, PGE2 and melanocyte stimulating hormone expression).

Beschreibung: A brief description of the Deterministic Modelling Hydrological System (DMHS) ‘Runoff–Erosion–Pollution’ proposed by the first author is presented. This system is being developed with the aim of giving it a universal character so that it can be applied in mountainous and flat terrain, and in basins of different natural climatic zones regardless of their size. The main feature of the model is its independence of the scaling problem. The basis of our approach consists of a simple theory of runoff elements. This is different from the generally accepted use of partial differential equations such as the Saint Venant equation for surface and channel flow and the Boussinesq equation for underground waters describing the water movement from runoff formation origins to the basin outlet. The results of runoff simulation for six mountainous watersheds of different sizes across Eastern Siberia within the Lena River basin and their statistical evaluation are presented. The selected river basins ranged in size from about 40 km2 (small scale) to the entire Lena River basin (2·4 million km2), classified as a large-scale basin.

Beschreibung: Many marine sponges contain massive numbers of largely uncultivated, phylogenetically diverse bacteria that seem to be important contributors to the chemistry of these animals. Insights into the diversity, origin, distribution, and function of their metabolic gene communities are crucial to dissect the chemical ecology and biotechnological potential of sponge symbionts. This study reveals a sharp dichotomy between high and low microbial abundance sponges with respect to polyketide synthase (PKS) gene content, the presence of methyl-branched fatty acids, and the presence of members of the symbiotic candidate phylum "Poribacteria". For the symbiont-rich sponge Cacospongia mycofijiensis, a source of the tubulin-inhibiting fijianolides (=laulimalides), near-exhaustive large-scale sequencing of PKS gene-derived PCR amplicons was conducted. Although these amplicons exhibit high diversity at the sequence level, almost all of them belong to a single, architecturally unique group of PKSs present in "Poribacteria" and are proposed to synthesize methyl-branched fatty acids. Three components of this PKS were studied in vitro, providing initial insight into its biochemistry.

Beschreibung: Transfer of the small gaseous molecules CO2 and NH3 across biological membranes, long thought to occur solely by simple diffusion, is now known to be facilitated by members of two multigene families: aquaporins (AQP) and rhesus (Rh) proteins. Although it is accepted that AQP1 and Rh proteins are involved in CO2 and NH3 transfer, respectively, the idea that a single channel can exhibit selectivity for both gases is controversial. Indeed, studies using the same in vitro model (human red blood cells) have provided evidence both for and against a role for Rh proteins as CO2 channels. Thus, this study was initiated to provide in vivo evidence for a dual function of Rh proteins as ammonia and CO2 channels. Here, we show that in zebrafish (Danio rerio), direct ammonia–CO2 competition experiments in adults or translational knockdowns of Rh proteins in larvae affects both ammonia and CO2 excretion. These results suggest that Rh proteins in zebrafish may be common pathways for transport of ammonia and CO2.

Beschreibung: Sex differences in behavior, morphology, and physiology are common in animals. In many bird species, differences in the feather colors of the sexes are apparent when judged by human observers and using physical measures of plumage reflectance, cryptic (to human) plumage dichromatism has also been detected in several additional avian lineages. However, it remains to be confirmed in almost all species whether sexual dichromatism is perceivable by individuals of the studied species. This latter step is essential because it allows the evaluation of alternative hypotheses regarding the signaling and communication functions of plumage variation. We applied perceptual modeling of the avian visual system for the first time to an endemic New Zealand bird to provide evidence of subtle but consistent sexual dichromatism in the whitehead, Mohoua albicilla. Molecular sexing techniques were also used in this species to confirm the extent of the sexual size dimorphism in plumage and body mass. Despite the small sample sizes, we now validate previous reports based on human perception that in male whiteheads head and chest feathers are physically brighter than in females. We further suggest that the extent of sexual plumage dichromatism is pronounced and can be perceived by these birds. In contrast, although sexual dimorphism was also detectable in the mass among the DNA-sexed individuals, it was found to be less extensive than previously thought. Sexual size dimorphism and intraspecifically perceivable plumage dichromatism represent reliable traits that differ between female and male whiteheads. These traits, in turn, may contribute to honest communication displays within the complex social recognition systems of communally breeding whitehead and other group-breeding taxa

Beschreibung: The coccolithophore Emiliania huxleyi (Lohmann) W. W. Hay et H. Mohler was cultured in natural seawater with the addition of either the microtubule-inhibitor colchicine, the actin-inhibitor cytochalasin B, or the photosynthesis inhibitor 3-(3,4 dichlorophenyl)-1,1-dimethyl-urea (DCMU). Additionally, E. huxleyi was cultured at different light intensities and temperatures. Growth rate was monitored, and coccolith morphology analyzed. While every treatment affected growth rate, the percentage of malformed coccoliths increased with colchicine, cytochalasin B, and at higher than optimal temperature. These results represent the first experimental evidence for the role of microtubules and actin microfilaments in coccolith morphogenesis.