A New Mechanistic Scenario for the Origin and Evolution of Vertebrate Cartilage

The appearance of cellular cartilage was a defining event in vertebrate evolution because it made possible the physical expansion of the vertebrate “new head”. Despite its central role in vertebrate evolution, the origin of cellular cartilage has been difficult to understand. This is largely due to a lack of informative evolutionary intermediates linking vertebrate cellular cartilage to the acellular cartilage of invertebrate chordates. The basal jawless vertebrate, lamprey, has long been considered key to understanding the evolution of vertebrate cartilage. However, histological analyses of the lamprey head skeleton suggest it is composed of modern cellular cartilage and a putatively unrelated connective tissue called mucocartilage, with no obvious transitional tissue. Here we take a molecular approach to better understand the evolutionary relationships between lamprey cellular cartilage, gnathostome cellular cartilage, and lamprey mucocartilage. We find that despite overt histological similarity, lamprey and gnathostome cellular cartilage utilize divergent gene regulatory networks (GRNs). While the gnathostome cellular cartilage GRN broadly incorporates Runx, Barx, and Alx transcription factors, lamprey cellular cartilage does not express Runx or Barx, and only deploys Alx genes in certain regions. Furthermore, we find that lamprey mucocartilage, despite its distinctive mesenchymal morphology, deploys every component of the gnathostome cartilage GRN, albeit in different domains. Based on these findings, and previous work, we propose a stepwise model for the evolution of vertebrate cellular cartilage in which the appearance of a generic neural crest-derived skeletal tissue was followed by a phase of skeletal tissue diversification in early agnathans. In the gnathostome lineage, a single type of rigid cellular cartilage became dominant, replacing other skeletal tissues and evolving via gene cooption to become the definitive cellular cartilage of modern jawed vertebrates

European Red List of Habitats Part 1. Marine habitats

The European Red List of Habitats provides an overview of the risk of collapse (degree of endangerment) of marine, terrestrial and freshwater habitats in the European Union (EU28) and adjacent regions (EU28+), based on a consistent set of categories and criteria, and detailed data and expert knowledge from involved countries1. A total of 257 benthic marine habitat types were assessed. In total, 19% (EU28) and 18% (EU28+) of the evaluated habitats were assessed as threatened in categories Critically Endangered, Endangered and Vulnerable. An additional 12% were Near Threatened in the EU28 and 11% in the EU28+. These figures are approximately doubled if Data Deficient habitats are excluded. The percentage of threatened habitat types differs across the regional seas. The highest proportion of threatened habitats in the EU28 was found in the Mediterranean Sea (32%), followed by the North-East Atlantic (23%), the Black Sea (13%) and then the Baltic Sea (8%). There was a similar pattern in the EU28+. The most frequently cited pressures and threats were similar across the four regional seas: pollution (eutrophication), biological resource use other than agriculture or forestry (mainly fishing but also aquaculture), natural system modifications (e.g. dredging and sea defence works), urbanisation and climate change. Even for habitats where the assessment outcome was Data Deficient, the Red List assessment process has resulted in the compilation of a substantial body of useful information to support the conservation of marine habitats

Survey of hard bottom vegetation in the archipelago of NW Aland in 1994

A survey of hard bottom vegetation was carried out in 1994 in NW Åland, N. Baltic Sea. The investigation covered 36 sites in three separate areas. The survey is part of a Nordic environmental programme for integrated ecological monitoring of coastal areas. The aim of this study was to describe the current status of the hard bottom vegetation, to gather basic quantitative data and to select suitable localities for future monitoring in NW Åland. The survey was carried out without the help of diving, and the conclusions are to a great extent based on the results of wading and raking along permanently marked vegetation profiles at each site. The qualitative results are expressed as occurrence, abundance and absolute and relative frequency of species. The quantitative results consist of biomass­and length measurements. All the three areas surveyed are of interest concerning future monitoring of macro­phytes, eventhough an internal comparison between the areas show that two of them (the most exposed one and the area closest to hydrologically defined middle-archipelago), according to their species diversity and the greater depth penetration of algae, are of greater value as international reference areas than the remaining area situated in a semi-sheltered sound. During the survey altogether 28 species were recorded: 10 seedplants, 2 charophytes, 4 chlorophytes, 5 phaeophytes and 7 rhodophytes

Phytobenthos in the Archipelago of NW Atand 1991 compared to 1963 and 1965

A survey of phytobenthos was carried out in 1991 in NW Åland, N. Baltic Sea. The investigation covered 35 sites along a transect from the sheltered inner-archipelago through semi-sheltered shores to unsheltered outer-archipelago areas. The study was done partly to get a picture of the species' diversity in the area, and partly to relocate stations and compare the situation to that of the early 1960's. The distribution of the phytobenthos was also compared to the general hydrographical situation. The comparison with earlier data (1963, -65) was based on an abundancy-scale ranging from 1 to 5, with 5 indicating the greatest density between shoots. The shallow parts of every site were surveilled on foot between lines drawn ten meters apart (sampling was done using different rakes within the marked grid). From one meters depth until the depths at which no macrophytes could be found, samples were taken at one-meter intervals. The archipelago area studied does not, based on the temporal comparison of phytobenthos, seem grossly affected by e.g. eutrophication, as few large-scale changes were recorded. This makes the area suitable for future monitoring and comparisons to follow any dramatic changes in the environment. Except for accumulation of soft bottoms in the inner archipelago-areas and growing amounts of reed, no significant changes in species-composition or -occurrence were recorded in the 42 species registered

Speech recovery and language plasticity can be facilitated by Sensori-Motor Fusion training in chronic non-fluent aphasia: A case report study

The rehabilitation of speech disorders benefits from providing visual information which may improve speech motor plans in patients. We tested the proof of concept of a rehabilitation method (Sensori-Motor Fusion, SMF; Ultraspeech player) in one post-stroke patient presenting chronic non-fluent aphasia. SMF allows visualisation by the patient of target tongue and lips movements using high-speed ultrasound and video imaging. This can improve the patient’s awareness of his/her own lingual and labial movements, which can, in turn, improve the representation of articulatory movements and increase the ability to coordinate and combine articulatory gestures. The auditory and oro-sensory feedback received by the patient as a result of his/her own pronunciation can be integrated with the target articulatory movements they watch. Thus, this method is founded on sensorimotor integration during speech. The SMF effect on this patient was assessed through qualitative comparison of language scores and quantitative analysis of acoustic parameters measured in a speech production task, before and after rehabilitation. We also investigated cerebral patterns of language reorganisation for rhyme detection and syllable repetition, to evaluate the influence of SMF on phonological-phonetic processes. Our results showed that SMF had a beneficial effect on this patient who qualitatively improved in naming, reading, word repetition and rhyme judgment tasks. Quantitative measurements of acoustic parameters indicate that the patient’s production of vowels and syllables also improved. Compared with pre-SMF, the fMRI data in the post-SMF session revealed the activation of cerebral regions related to articulatory, auditory and somatosensory processes, which were expected to be recruited by SMF. We discuss neurocognitive and linguistic mechanisms which may explain speech improvement after SMF, as well as the advantages of using this speech rehabilitation method