38 research outputs found
Focal-Plane Change Triggered Video Compression for Low-Power Vision Sensor Systems
Video sensors with embedded compression offer significant energy savings in transmission but incur energy losses in the complexity of the encoder. Energy efficient video compression architectures for CMOS image sensors with focal-plane change detection are presented and analyzed. The compression architectures use pixel-level computational circuits to minimize energy usage by selectively processing only pixels which generate significant temporal intensity changes. Using the temporal intensity change detection to gate the operation of a differential DCT based encoder achieves nearly identical image quality to traditional systems (4dB decrease in PSNR) while reducing the amount of data that is processed by 67% and reducing overall power consumption reduction of 51%. These typical energy savings, resulting from the sparsity of motion activity in the visual scene, demonstrate the utility of focal-plane change triggered compression to surveillance vision systems
Cyanobacteria of the thermal spring at Pancharevo, Sofia, Bulgaria
Eight taxa of cyanobacteria were identified in the thermal spring at Pancharevo (in the Sofia basin, Bulgaria). As well as the widespread Lyngbya thermalis, Phormidesmis molle (syn. Phormidium molle), Phormidium papyraceum, Phormidium corium and Mastigocladus laminosus, four species were identified for the first time in Bulgaria: Calothrix thermalis, Gloeocapsa gelatinosa, Leibleinia epiphytica and Symploca thermalis
Collaborative database to track Mass Mortality Events in the Mediterranean Sea
Anthropogenic climate change, and global warming in particular, has strong and increasing impacts on marine ecosystems (Poloczanska et al., 2013; Halpern et al., 2015; Smale et al., 2019). The Mediterranean Sea is considered a marine biodiversity hotspot contributing to more than 7% of world\u2019s marine biodiversity including a high percentage of endemic species (Coll et al., 2010). The Mediterranean region is a climate change hotspot, where the respective impacts of warming are very pronounced and relatively well documented (Cramer et al., 2018). One of the major impacts of sea surface temperature rise in the marine coastal ecosystems is the occurrence of mass mortality events (MMEs). The first evidences of this phenomenon dated from the first half of \u201980 years affecting the Western Mediterranean and the Aegean Sea (Harmelin, 1984; Bavestrello and Boero, 1986; Gaino and Pronzato, 1989; Voultsiadou et al., 2011). The most impressive phenomenon happened in 1999 when an unprecedented large scale MME impacted populations of more than 30 species from different phyla along the French and Italian coasts (Cerrano et al., 2000; Perez et al., 2000). Following this event, several other large scale MMEs have been reported, along with numerous other minor ones, which are usually more restricted in geographic extend and/or number of affected species (Garrabou et al., 2009; Rivetti et al., 2014; Marb\ue0 et al., 2015; Rubio-Portillo et al., 2016, authors\u2019 personal observations). These events have generally been associated with strong and recurrent marine heat waves (Crisci et al., 2011; Kersting et al., 2013; Turicchia et al., 2018; Bensoussan et al., 2019) which are becoming more frequent globally (Smale et al., 2019). Both field observations and future projections using Regional Coupled Models (Adloff et al., 2015; Darmaraki et al., 2019) show the increase in Mediterranean sea surface temperature, with more frequent occurrence of extreme ocean warming events. As a result, new MMEs are expected during the coming years. To date, despite the efforts, neither updated nor comprehensive information can support scientific analysis of mortality events at a Mediterranean regional scale. Such information is vital to guide management and conservation strategies that can then inform adaptive management schemes that aim to face the impacts of climate change
Are well-studied marine biodiversity hotspots still blackspots for animal barcoding?
Marine biodiversity underpins ecosystem health and societal well-being. Preservation of biodiversity hotspots is a global challenge. Molecular tools, like DNA barcoding and metabarcoding, hold great potential for biodiversity monitoring, possibly outperforming more traditional taxonomic methods. However, metabarcoding-based biodiversity assessments are limited by the availability of sequences in barcoding reference databases; a lack thereof results in high percentages of unassigned sequences. In this study we (i) present the current status of known vs. barcoded marine species at a global scale based on online taxonomic and genetic databases; and (ii) compare the current status with data from ten years ago. Then we analyzed occurrence data of marine animal species from five Large Marine Ecosystems (LMEs) classified as biodiversity hotspots, to identify any consistent disparities in COI barcoding coverage between geographic regions and at phylum level. Barcoding coverage varied among LMEs (from 36.8% to 62.4% COI-barcoded species) and phyla (from 4.8% to 74.7% COI-barcoded species), with Porifera, Bryozoa and Platyhelminthes being highly underrepresented, compared to Chordata, Arthropoda and Mollusca. We demonstrate that although barcoded marine species increased from 9.5% to 14.2% since the last assessment in 2011, about 15,000 (corresponding to 7.8% increase) new species were described from 2011 to 2021. The next ten years will thus be crucial to enroll concrete collaborative measures and long term initiatives (e.g., Horizon 2030, Ocean Decade) to populate barcoding libraries for the marine realm.the Department of Biological, Geological and Environmental Sciences (BiGeA) of the University of Bologna (UniBo).
The CoMBoMed initiative was supported by the European Marine Research Network (EUROMARINE Network), the
Inter-Departmental Research Centre for Environmental Sciences (CIRSA – UniBo), the Cultural Heritage Department
(DBC - UniBo, https://beniculturali.unibo.it/it), the Fondazione Flaminia and the ERANet Mar-Tera Project SEAMoBB
(Solutions for sEmi-Automated Monitoring of Benthic Biodiversity).Peer reviewe
Biological soil crusts of Arctic Svalbard and of Livingston Island, Antarctica
Biological soil crusts (BSCs) occur in arid and semi-arid regions worldwide including the Polar Regions. They are important ecosystem engineers, and their composition and areal coverage should be understood before assessing key current functional questions such as their role in biogeochemical nutrient cycles and possible climate change scenarios. Our aim was to investigate the variability of BSCs from Arctic Svalbard and the Antarctic Island, Livingston, using vegetation surveys based on classification by functional group. An additional aim was to describe the structure of BSCs and represent a classification system that can be used in future studies to provide a fast and efficient way to define vegetation type and areal coverage. Firstly, this study demonstrates huge areas occupied by BSCs in Arctic Svalbard, with up to 90 % of soil surface covered, dominated by bryophytes and cyanobacteria, and showing an unexpectedly high variability in many areas. Livingston Island has lower percentage coverage, up to 55 %, but is dominated by lichens. Our findings show that both Polar Regions have varied BSC coverage, within the sites and between them, especially considering their harsh climates and latitudinal positions. Secondly, we have classified the BSCs of both areas into a system that describes the dominant functional groups and local geography, creating a simple scheme that allows easy identification of the prevailing vegetation type. Our results represent the first contribution to the description of BSCs based on their functional group composition in Polar Regions
A baseline of epibenthic species distribution on the northern Adriatic mesophotic biogenic reefs
In the northern Adriatic continental shelf, hundreds of mesophotic biogenic reefs, ranging in size from tens to many thousands square meters, are scattered on sandy and muddy bottoms. The study of their epibenthic assemblages, which started in the early 2000s, is continuing with the exploration of new sites at increasingly depth and distance from the coast, providing new insights into species diversity and distribution. The first intensive survey carried out in 2013-2014 from Chioggia to Grado provided data on 55 epibenthic taxa occurring in 12 sites. The second survey, carried out in summer 2017 with the same sampling effort (12 sites, 10 photographic samples per site) but extended to two remote outcrops and with only 4 sites in common with the previous survey, recorded 83 taxa (33 added and 5 not recovered). The two deepest and farthermost outcrops, 31-32 m depth and about 27 nm off Chioggia, hosted sponge gardens mainly composed by dense populations of Polymastia boletiformis (Lamarck, 1815), Polymastia mamillaris (Müller, 1806) and Ulosa stuposa (Esper, 1794). Meanwhile, some previously unexplored outcrops off Grado, close to the midline between Italy and Croatia, revealed assemblages extremely rich in sponges and colonial ascidians. Among the newly recorded taxa there were 15 sponges, 2 anthozoans, 3 bryozoans and 8 ascidians. The data currently available represent a new baseline of knowledge on the diversity of northern Adriatic mesophotic biogenic habitats. This may help to understand their resistance and resilience to human and climate change threats, and develop transboundary ecosystem-based management
Combining high resolution computed tomography and scanning electron microscopy to assess biocontruction and bioerosion processes in biogenic reefs
Benthic assemblages of biogenic reefs in the northern Adriatic Sea: synthesis and new insights
Biogenic reefs in the northern Adriatic Sea have a high ecological and economic value, but
they are subject to different impacts and require more protection. Here we reviewed recent literature on biogenic reefs and presented new data on their diversity, connectivity and the potential factors affecting species distribution. Results showed that biogenic reefs have a high spatial heterogeneity primarily driven by hydrodynamic factors and nutrient loads. Connectivity simulation helped to explain this diversity and stressed that current protection measures should be extended to other important sites for species dispersal
Benthic assemblages of biogenic reefs in the northern Adriatic Sea: Synthesis and new insights
Biogenic reefs in the northern Adriatic Sea have a high ecological and economic value, but they are subject to different impacts and require more protection. Here we reviewed recent literature on biogenic reefs and presented new data on their diversity, connectivity and the potential factors affecting species distribution. Results showed that biogenic reefs have a high spatial heterogeneity primarily driven by hydrodynamic factors and nutrient loads. Connectivity simulation helped to explain this diversity and stressed that current protection measures should be extended to other important sites for species dispersal