Petrologic and geochemical characteristics of the Krivaja-Konjuh ophiolite complex (NE Bosnia and Herzegovina) - petrogenesis and regional geodynamic implications

Based on its petrological and geochemical characteristics, the Krivaja-Konjuh Ophiolite Complex (KKOC) and the surrounding ophiolitic mélange make an integral part of the Central Dinaridic Ophiolite Belt (CDOB) of the Internal Dinarides. The Jurassic ultramafic and mafic sequences form about 80 % of the KKOC, whereas the rest belongs to the metamorphic sole, which is found concentrating in the northwestern and southern margins. The KKOC ultramafic rocks, comprising lherzolites, pyroxenites, dunites, along with rocks from the metamorphic sole and chromitites were subjected to an extensive analytical investigation, which included EMPA and SEM studies, and XRF and ICP-MS analyses, in order to reveal their mineralogical, geochemical and petrological characteristics. The lherzolitic modal mineralogy consists of olivine, orthopyroxene, clinopyroxene, spinel and occasionally plagioclase. With respect to clear differences in modal mineralogy, as well as in phase and bulk-rock chemistry, one is able to distinguish two main varieties among the KKOC lherzolites. The first one renders spinel lherzolites, whilst the second variety is known as plagioclase lherzolites. Geothermometric estimations yielded the main equilibration range, for both spinel and plagioclase lherzolites, to range from 809 to 1012 °C (T1). The Fe-Mg exchange between olivine and spinel provided a temperature range of 550-682°C (T2), which is found to be indicative for subsolidus reequilibration processes. Using the oceanic and rift-ridge geotherms, the equilibration pressures extending from 1.2 to 2.0 GPa (ca. 40-65 km depth) were inferred for T1 temperatures. Numerous geochemical parametres are pointing to the KKOC lherzolites as fertile solid residues, which, before metamorphism, underwent low to moderate degrees of MOR melting. The mineral chemistry of spinel and the REE normalisation levels (relative to chondrite) yielded an average batch melting degree of ~7.7 % for spinel lherzolites. Part of the eastern segment of the KKOC is reported to deviate from the MOR fertile geochemistry. The occurrence of pargasite, coupled with a Cr-enriched spinel, call for enhanced mantle melting (~ 15 %) in a SSZ-type of setting. Contrary to the amphibole formation in a SSZ mantle wedge, geochemical evidences clarify the growth of plagioclase through sub-solidus equilibration (T2) and melt metasomatism of the lithospheric mantle at a MOR-type setting. It can be concluded that the main part of the KKOC lherzolites presents a segment of mantle column, which experienced relatively fast and continuous adiabatic ascent under the spreading MOR environment. Within the KKOC metamorphic unit, a variety of paragenesis, textures and structures was recognised. Based on the general classification criteria set for metamorphic rocks, the following varieties among KKOC metamorphic rocks were distinguished: (1) granoblastic amphibolite, (2) garnet-diopside amphibolite, (3)garnet-diopside-hypersthene amphibolite, (4) diopside gneiss and (5) plagioclase garnet-diopside gneiss. Major and trace element geochemistry, as well as petrographic data show that 2/3 of metamorphic rocks bear geochemical signatures of mafic to ultramafic gabbroic rocks, whereas the rest corresponds to more evolved basalts of tholeiitic affinity. Geothermobarometric calculations, based on the phase chemistry of different coexisting minerals, yielded ranges of temperature and pressure for the different KKOC petrographic varieties, as follows: (a) ~ 880 °C and 0.90-1.30 GPa for granoblastic amphibolites, (b) 802-1028 °C and 0.94-1.40 GPa for garnet-diopside amphibolites, (c) for garnet-diopside-hypersthene amphibolites the metamorphic conditions are analogue to the previous variety, recording slightly reduced pressure values, (d) 0.84-0.89 GPa for diopside amphibolites, with no temperature data, and (e) 729-890 °C and 1.10-1.60 GPa for splagioclase-garnet-diopside gneisses. Due to the striking similarities of CDOB with ophiolitic complexes in Albania and Greece, the geodynamic evolution of KKOC is bound to the Mesozoic evolution of the Pindos Ocean, a Tethyan back-arc type of ocean. In order to reconcile the features of two contrasting geotectonic settings (MOR and SSZ) displayed by almost all KKOC lithological units, one suggests that a subducted slab must have been placed under the Krivaja-Konjuh mantle domain. The metamorphic sole is also related to such a defined intra-oceanic subduction and underplating of the cold oceanic crust under the hot mantle wedge. During the late Jurassic to early Cretaceous transition period, the subduction trench collided with the Adriatic microplate, and the KKOC among other CDOB ultramafic complexes was thrust southwestwards on the Adriatic carbonate platform. Throughout the emplacement, the eastern KKOC mantle portion was most probably tectonically exhumed along the ancient subduction channels, causing an erosion of the above placed plagioclase-containing lithospheric mantle

Experimental Evaluation of Autonomous Driving Based on Visual Memory and Image Based Visual Servoing

International audienceIn this paper, the performance of a topological metric visual-path-following framework is investigated in different environments. The framework relies on a monocular camera as the only sensing modality. The path is represented as a series of refer- ence images such that each neighboring pair contains a number of common landmarks. Local 3-D geometries are reconstructed between the neighboring reference images to achieve fast feature prediction. This condition allows recovery from tracking failures. During navigation, the robot is controlled using image-based vi- sual servoing. The focus of this paper is on the results from a num- ber of experiments that were conducted in different environments, lighting conditions, and seasons. The experiments with a robot car show that the framework is robust to moving objects and moderate illumination changes. It is also shown that the system is capable of online path learning

A framework for scalable vision-only navigation

International audienceThis paper presents a monocular vision framework enabling feature-oriented appearance-based navigation in large outdoor environ- ments containing other moving ob jects. The framework is based on a hybrid topological-geometrical environment representation, constructed from a learning sequence acquired during a robot motion under hu- man control. The framework achieves the desired navigation functional- ity without requiring a global geometrical consistency of the underlying environment representation. The main advantages with respect to con- ventional alternatives are unlimited scalability, real-time mapping and effortless dealing with interconnected environments once the loops have been properly detected. The framework has been validated in demanding, cluttered and interconnected environments, under different imaging con- ditions. The experiments have been performed on many long sequences acquired from moving cars, as well as in real-time large-scale navigation trials relying exclusively on a single perspective camera. The obtained results imply that a globally consistent geometric environment model is not mandatory for successful vision-based outdoor navigation

Unique Aggregation of Sterigmatocystin in Water Yields Strong and Specific Circular Dichroism Response Allowing Highly Sensitive and Selective Monitoring of Bio-Relevant Interactions

We demonstrated the hitherto unknown property of the mycotoxin sterigmatocystin (STC) to provide homogeneous solutions in aqueous medium by forming a unique aggregate type (not formed by analogous aflatoxins), characterized by exceptionally strong circular dichroism (CD) bands in the 300-400 nm range. Results showed that these CD bands do not originate from intrinsic STC chirality but are a specific property of a peculiar aggregation process similar to psi-DNA CD response. Transmission electron microscopy (TEM) experiments revealed a fine fiber network resembling a supramolecular gel structure with helical fibers. Thermodynamic studies of aggregates by differential scanning calorimetry (DSC) revealed high reversibility of the dominant aggregation process. We demonstrated that the novel STC psi-CD band at 345 nm could be applied at biorelevant conditions (100 nanomolar concentration) and even in marine-salt content conditions for specific and quantitative monitoring of STC. Also, we showed that STC strongly non-covalently interacts with ds-DNA with likely toxic effects, thus contrary to the previous belief requiring prior enzyme epoxidation

Distribution of non-native Pacific oyster Magallana gigas (Thunberg, 1793) along the eastern Adriatic coast

Non-native Pacific oyster Magallana gigas (Thunberg, 1793) was introduced to the Mediterranean Sea for aquaculture purposes in the 1960s. Although this species was not introduced for aquaculture to the Croatian part of the Adriatic Sea, in the 1970s, it was reported in the Lim Bay, in the North-eastern Adriatic. Until recently, there has been no research on the species in the Croatian part of the Adriatic. The aim of this research was to summarize existing and novel data on the distribution of M. gigas in coastal areas of the Eastern Adriatic and to provide a baseline for the future monitoring and assessment programmes of the species. Distribution of M. gigas was determined by three different methods: (i) a visual census of the presence of M. gigas specimens in the medio-littoral zone ; (ii) DNA identification of M. gigas larvae in the water column ; and (iii) the presence of M. gigas in the subtidal zone at depth between 25 and 40 m. Magallana gigas has a well- established population in the medio-littoral zone of natural and anthropogenic habitats along the coast of the North-eastern Adriatic Sea (west coast of Istria peninsula), but it is not present in the deeper layers . In the Central-eastern and South-eastern Adriatic Sea, the species was either absent or sporadically recorded with no evidence of fully established populations. Considering the great invasion success of M. gigas worldwide and effects that this species could have on the invaded ecosystem (e.g. competition for food and space with native species), detailed future monitoring is needed for the Eastern Adriatic Sea

A Novel Approach for the Treatment of Aerobic Vaginitis: Azithromycin Liposomes-in-Chitosan Hydrogel

Biocompatible mucoadhesive formulations that enable a sustained drug delivery at the site of action, while exhibiting inherent antimicrobial activity, are of great importance for improved local therapy of vaginal infections. The aim of this research was to prepare and evaluate the potential of the several types of azithromycin (AZM)-liposomes (180–250 nm) incorporated into chitosan hydrogel (AZM-liposomal hydrogels) for the treatment of aerobic vaginitis. AZM-liposomal hydrogels were characterized for in vitro release, and rheological, texture, and mucoadhesive properties under conditions simulating the vaginal site of application. The role of chitosan as a hydrogel-forming polymer with intrinsic antimicrobial properties was explored against several bacterial strains typical for aerobic vaginitis as well as its potential effect on the anti-staphylococcal activity of AZM-liposomes. Chitosan hydrogel prolonged the release of the liposomal drug and exhibited inherent antimicrobial activity. Additionally, it boosted the antibacterial effect of all tested AZM-liposomes. All AZM-liposomal hydrogels were biocompatible with the HeLa cells and demonstrated mechanical properties suitable for vaginal application, thus confirming their potential for enhanced local therapy of aerobic vaginitis

Reduced sediment supply in a fast eroding landscape? A multi-proxy sediment budget of the upper Rhone basin, Central Alps

Alpine water and sediment supply influence the sediment budget of many important European fluvial systems such as the Rhine, Rhône and Po rivers. In the light of human induced climate change and landscape modification, it becomes increasingly important to understand the mechanisms of sediment production and supply in Alpine sediment systems. This study aims to investigate the modern sediment budget of the upper Rhône basin, one of the largest Alpine intramontane watersheds, located in the Central Alps of southwestern Switzerland. Major areas of sediment generation are fingerprinted by framework petrography, heavy mineral concentrations and bulk geochemistry. The relative contributions of the three major sources to the sediment of the trunk Rhône river are identified by compositional mixing modelling. Concentrations of the terrestrial cosmogenic nuclide 10Be measured in quartz separated from fluvial sediments provide spatially averaged denudation rates for selected tributary basins. Results from sediment fingerprinting and mixing modelling suggest that tributaries located in the North and the East of the catchment are generating most of the sediment transported by the Rhône river to its primary sedimentary sink in Lake Geneva. Despite having some of the highest denudation rates within the basin, tributaries located in the southern area of the Rhône basin are relatively underrepresented in the sediment budget of the Rhône river. These tributaries are severely affected by human activities, for example through sediment mining as well as water and sediment abstraction in large hydropower reservoirs. Together, these processes reduce the basin-wide sediment discharge by about 50%, thereby explaining most of the observed compositional pattern. In addition, there is evidence suggesting that large amounts of glaciogenic sediments are currently supplied by retreating glaciers. Glaciogenic material with its low 10Be concentrations can lead to a significant overestimation of denudation rates and thus limit the applicability of cosmogenic nuclide analysis in such glaciated settings

A plant-based diet supplemented with Hermetia illucens alone or in combination with poultry by-product meal: one step closer to sustainable aquafeeds for European seabass

Background: Increasing demand for high-value fish species and pressure on forage fish is challenging aquaculture to ensure sustainable growth by replacing protein sources in aquafeeds with plant and terrestrial animal proteins, without compromising the economic value and quality of the final fish product. In the present study, the effects of a plant protein-based diet (CV), two plant-based diets in which graded amounts of plan protein mixtures were replaced with Hermetia illucens meal alone (VH10) or in combination with poultry by-product meal (PBM) (VH10P30), a fishmeal (FM) diet (CF) and an FM diet supplemented with H. illucens (FH10) on growth performance, gut health and homeostasis of farmed subadult European seabass were tested and compared. Results: Fish fed the VH10 and VH10P30 diets showed the highest specific growth rates and lowest feed conversion ratios among the tested groups. Expectedly, the best preservation of PI morphology was observed in fish fed the CF or FH10 diets, while fish fed the CV diet exhibited significant degenerative changes in the proximal and distal intestines. However, PBM supplementation mitigated these effects and significantly improved all gut morphometric parameters in the VH10P30 group. Partial substitution of the plant mixture with insect meal alone or PBM also induced most BBM genes and activated BBM enzymes, suggesting a beneficial effect on intestinal digestive/absorption functions. Regarding intestinal microbiota, fish fed diets containing H. illucens meal (FH10, VH10, VH10P30) had the highest richness of bacterial communities and abundance of beneficial genera such as Lactobacillus and Bacillus. On the other hand, fish fed CV had the highest microbial diversity but lost a significant component of fish intestinal microbiota, the phylum Bacteroidetes. Finally, skin pigmentation most similar to that of farmed or even wild seabass was also observed in the fish groups fed CF, FH10 or VH10P30. Conclusion: Plant-based diets supplemented with PBM and H. illucens pupae meal have great potential as alternative diets for European seabass, without affecting growth performance, gut homeostasis, or overall fitness. This also highlights the importance of animal proteins in diets of European seabass, as the addition of a small amount of these alternative animal protein sources significantly improved all measured parameters

A New Solution to the Relative Orientation Problem using only 3 Points and the Vertical Direction

This paper presents a new method to recover the relative pose between two images, using three points and the vertical direction information. The vertical direction can be determined in two ways: 1- using direct physical measurement like IMU (inertial measurement unit), 2- using vertical vanishing point. This knowledge of the vertical direction solves 2 unknowns among the 3 parameters of the relative rotation, so that only 3 homologous points are requested to position a couple of images. Rewriting the coplanarity equations leads to a simpler solution. The remaining unknowns resolution is performed by an algebraic method using Grobner bases. The elements necessary to build a specific algebraic solver are given in this paper, allowing for a real-time implementation. The results on real and synthetic data show the efficiency of this method