Variabilità spazio-temporale della microalga <i>Chrysophaeum taylorii</i> Lewis &amp; Bryan lungo le coste nord-orientali della Sardegna = Spatio-temporal variabilty of the microalga <i>Chrysophaeum taylorii</i> Lewis &amp; Bryan along North-Eastern Sardinian coasts

In the summer months of 2010 the cell density of the alien benthic microalga Chrysophaeum taylorii Lewis &amp; Bryan (Pelagophyceae) was assessed on hard benthic substrates in sixteen study sites along the north-eastern coast of Sardinia in order to obtain useful information on spatial and temporal variations of the species in the area during summer

Esperimento di rimozione degli ammassi mucillaginosi della microalga alloctona <i>Chrysophaeum taylorii</i> Lewis &amp; Bryan = Experiment of removal of the mucilaginous aggregates by the alien microalga <i>Chrysophaeum taylorii</i> Lewis &amp; Bryan

A manipulative experiment was carried out in a small bay of Tavolara Punta Coda Cavallo Marine Protected Area in order to investigate the triggers for formation and storage of the macroscopic mucilaginous aggregates of the benthic microalga Chrisophaeum taylorii Lewis &amp; Bryan (Pelagophyceae) and to test the efficacy of mucillage removal

Distribution and density of the benthic microalga <i>Chrysophaeum taylorii</i> Lewis &amp; Bryan from Northern to central-Eastern Sardinian coasts = Distribuzione e densità della microalga bentonica <i>Chrysophaeum taylorii</i> Lewis &amp; Bryan dalle coste nord a quelle centro orientali della Sardegna

In August 2009 the distribution and density of the alien microalga Chrysophaeum taylorii Lewis &amp; Bryan (Pelagophyceae) were investigated on hard benthic substrates in seventeen sites from northern to central-eastern Sardinia, in order to estimate the distribution and abundance of this species in the area

Comparative evaluation of multiple protein extraction procedures from three species of the genus Caulerpa

AbstractThe aim of this study was to define the simplest and least expensive protocol for total protein extraction for three different macroalgae of the genus Caulerpa (the invasive C. taxifolia and C. cylindracea and the autochthonous C. prolifera). Five multi-step protein extraction procedures, set up for other macroalgal species, were tested. For each of them, different pre-treatment and extraction conditions were simultaneously examined, according to a factorial design, considering the starting material, the solvent-to-biomass ratio, and the incubation temperature. Protein yield in the obtained extracts was estimated with the Bradford method. Further, polyacrylamide gel electrophoresis (SDS-PAGE) was used to resolve proteins, assessing their quality and integrity. Significant differences in protein yield were observed among the extraction protocols and the conditions tested, also in relation to the considered species. Profiles having an acceptable quality were obtained for C. prolifera and C. cylindracea, and from the obtained results, the best method to obtain high yield and quality protein extracts for the two above-mentioned species appears to require the use of a primary TCA/acetone extraction buffer followed by a lysis buffer with NaCl, KCl, urea, Triton, SDS and a protease inhibitor. The best results, in particular, were obtained starting from fresh pulped material with a buffer-to-biomass ratio of 10:1 and an incubation temperature of 4°C. For C. taxifolia, instead, none of the tested protocols produced satisfactory results and further studies will be required

Consumer depletion alters seagrass resistance to an invasive macroalga

Few field studies have investigated how changes at one trophic level can affect the invasibility of other trophic levels. We examined the hypothesis that the spread of an introduced alga in disturbed seagrass beds with degraded canopies depends on the depletion of large consumers. We mimicked the degradation of seagrass canopies by clipping shoot density and reducing leaf length, simulating natural and anthropogenic stressors such as fish overgrazing and water quality. Caulerpa racemosa was transplanted into each plot and large consumers were excluded from half of them using cages. Potential cage artifacts were assessed by measuring irradiance, scouring by leaf movement, water flow, and sedimentation. Algal invasion of the seagrass bed differed based on the size of consumers. The alga had higher cover and size under the cages, where the seagrass was characterized by reduced shoot density and canopy height. Furthermore, canopy height had a significant effect depending on canopy density. The alteration of seagrass canopies increased the spread of C. racemosa only when large consumers were absent. Our results suggest that protecting declining habitats and/or restoring fish populations will limit the expansion of C. racemosa. Because MPAs also enhance the abundance and size of fish consuming seagrass they can indirectly promote algal invasion. The effects of MPAs on invasive species are context dependent and require balancing opposing forces, such as the conservation of seagrass canopy structure and the protection of fish grazing the seagrass

The interactive effect of herbivory, nutrient enrichment and mucilage on shallow rocky macroalgal communities

This paper focuses on the interactive short and long-term effect of three different stressors on a macroalgal assemblage. Three stressors are considered: herbivory, nutrients and mucilage. The experiment was conducted in Tavolara Punta Coda Cavallo Marine Protected Area (Mediterranean Sea) during a bloom of the benthic mucilage-producing microalga Chrysophaeum taylorii (Pelagophyceae); this microalga is recently spreading in the Mediterranean Sea. On a rocky substratum, 36 plots 20 × 20 cm in size were prepared. Factorial combinations of three experimental treatments were applied in triplicate, including three grazing levels crossed with two nutrient enrichment and two mucilage removal treatments. Significant differences were observed among treatments 8 weeks later, at the end of summer. In particular, dark filamentous algae were more abundant in all enriched plots, especially where mucilage and macroalgae had been removed; a higher percent cover of crustose coralline algae was instead observed where nutrients had been increased and no grazing pressure acted. Furthermore, the abundance of Dictyota spp. and Laurencia spp. was significantly higher in enriched mucilage-free plots where the grazing pressure was null or low. However, the effects of the treatments on the overall assemblage of the macroalgal community were not long persistent (36 weeks later). These results illustrate the capacity of a shallow-water macroalgal community to quickly recover from the simultaneous impacts of herbivory, nutrient enrichment, and mucilage

Preliminary data on the genetic variability of the fan mussel <i>Pinna nobilis</i> in the Northern Sardinia = Dati preliminari sulla variabilità genetica del mollusco bivalve <i>Pinna nobilis</i> nella Sardegna settentrionale

The fan mussel Pinna nobilis Linnaeus, 1758 is one of the most endangered Mediterranean bivalve. After a reduction of its distribution as a consequence of anthropic factors, the environmental politics led to a new demographic increasing of individuals in some Mediterranean regions. This work aimed to shed some light on the genetic structure of two new-raised populations in northern Sardinia

Renewal in the church, social reconstruction and a community on Iona : the origins and development of George MacLeod's Christian Social Vision in 1930s Scotland

This thesis argues that George MacLeod, Church of Scotland minister and popular radio preacher, developed a distinctive Christian social vision whilst working in Govan, in the 1930s. The vision, which called for renewal in corporate worship and a new ‘social gospel’, has been underestimated in its importance. For renewal, he promoted aspects of liturgical and sacramental traditions within Scoto and Anglo-Catholicism and reinterpreted doctrine and scripture in the light of modern scientific and biblical scholarship, encouraging more sophisticated expressions of faith for increasingly literate congratulations. His ‘social gospel’ and new theological profile, influenced by Anglican expressions of ‘Christian Socialism’, developed in response to endemic social injustices within mature capitalist economies, rising collective movements and communist and fascist ideologies, which threatened to remove injustices through violent means. MacLeod sympathised increasingly with political socialism, supporting gradual and peaceful reform. His eclectic vision grew out of experiences of war, the legacy of previous MacLeod Tory paternalists and radical clerics, by the theatre and symbolism of Eastern Orthodox traditions and popular themes within ‘Celtic Christianity’. These reinforced his emphasis on the incarnation, divine immanence, ecumenism and community; themes associated with ‘Christian Socialism’. MacLeod joined John White’s crusade, in the 1930s, to review national religion, the parish system and godly commonwealth ideal. However, admiring the ecumenical movement and figures like John Baillie and William Temple, he sought a united Christian witness across boundaries of nation, ethnicity, class and denomination. Iona, boasting its important pre-reformation Christian witness, seemed to symbolise an indigenous yet ecumenical expression of the faith, during Scotland’s interwar romantic cultural renaissance. This research contextualises his teachings, explains the development of his vision and uncovers the original purpose of the Iona Community he founded in 1938, more fully than any previous research.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Accidental Introduction and Spread of Top Invasive Alien Plants in the European Union through Human-Mediated Agricultural Pathways: What Should We Expect?

Alien species are among the five drivers of environmental change with the largest relative global impacts. In particular, horticulture is a major introduction pathway of alien plants, but, together with intentional introductions, plants can also be introduced and spread via human-mediated involuntary pathways as contaminants and stowaways. Recurring accidental introductions of alien plants to new areas can be the prelude to invasion on a large scale. Agriculture represents a sector that is severely impacted by invasive alien species and, at the same time, it is likely to be one of the main factors responsible of biological invasions. So, the present review highlights risks related to accidental introduction though human-mediated agricultural pathways of a politically relevant group of alien plants, invasive alien plants of Union concern (IAPUC), that are species whose prevention and management is mandatory in the European Union according to Regulation (EU) n. 1143/2014. Even if most IAPUC have been primarily introduced as economic plants, several accidental pathways related to agriculture can be identified for each one of them. The implementation of technologies and the sharing of good practices, at a wide scale and at different levels of the society, would help in overcoming several problematic issues related to the accidental transport of IAPUC