298 research outputs found

    Lower genetic diversity in the limpet Patella caerulea on urban coastal structures compared to natural rocky habitats

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    Human-made structures are increasingly found in marine coastal habitats. The aim of the present study was to explore whether urban coastal structures can affect the genetic variation of hard-bottom species. We conducted a population genetic analysis on the limpet Patella caerulea sampled in both natural and artificial habitats along the Adriatic coast. Five microsatellite loci were used to test for differences in genetic diversity and structure among samples. Three microsatellite loci showed strong Hardy-Weinberg disequilibrium likely linked with the presence of null alleles. Genetic diversity was significantly higher in natural habitat than in artificial habitat. A weak but significant differentiation over all limpet samples was observed, but not related to the type of habitat. While the exact causes of the differences in genetic diversity deserve further investigation, these results clearly point that the expansion of urban structures can lead to genetic diversity loss at regional scales

    Marine forests of the Mediterranean-Atlantic Cystoseira tamariscifolia complex show a southern Iberian genetic hotspot and no reproductive isolation in parapatry

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    Climate-driven range-shifts create evolutionary opportunities for allopatric divergence and subsequent contact, leading to genetic structuration and hybrid zones. We investigate how these processes influenced the evolution of a complex of three closely related Cystoseira spp., which are a key component of the Mediterranean-Atlantic seaweed forests that are undergoing population declines. The C. tamariscifolia complex, composed of C. tamariscifolia s.s., C. amentacea and C. mediterranea, have indistinct boundaries and natural hybridization is suspected. Our aims are to (1) infer the genetic structure and diversity of these species throughout their distribution ranges using microsatellite markers to identify ancient versus recent geographical populations, contact zones and reproductive barriers, and (2) hindcast past distributions using niche models to investigate the influence of past range shifts on genetic divergence at multiple spatial scales. Results supported a single, morphologically plastic species the genetic structure of which was incongruent with a priori species assignments. The low diversity and low singularity in northern European populations suggest recent colonization after the LGM. The southern Iberian genetic hotspot most likely results from the role of this area as a climatic refugium or a secondary contact zone between differentiated populations or both. We hypothesize that life-history traits (selfing, low dispersal) and prior colonization effects, rather than reproductive barriers, might explain the observed genetic discontinuities.Pew Charitable Trusts (USA); MARINERA, Spain [CTM2008-04183-E/MAR]; FCT (Portugal) [FCT-BIODIVERSA/004/2015, CCMAR/Multi/04326/2013, SFRH/BPD/107878/2015, SFRH/BPD/85040/2012]; FPU fellowship of the Spanish Ministry of Education; European Community ASSEMBLE visiting grant [00399/2012]; University of Cadi

    Limited proteolysis of a disulfide-linked apoA-I dimer in reconstituted HDL.

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    The apolipoprotein A-I Milano (apoA-I M ) is a mo- lecular variant of apoA-I characterized by the Arg 173 → Cys substitution, leading to the formation of homodimers A-I M / A-I M. Upon interaction with palmitoyloleoylphosphatidyl- choline, A-I M /A-I M forms only two species of reconstituted HDL (rHDL) particles, with diameters of 7.8 and 12.5 nm. We used limited proteolysis to analyze the conformation of A-I M /A-I M in the two rHDL particles, in comparison with that of apoA-I in rHDL of similar size. ApoA-I in the small, 7.8-nm rHDL is degraded to a greater extent (50% after 6 h) than in the large rHDL ( � 10% degraded after 6 h). The pro- tease susceptibility of A-I M /A-I M in small and large rHDL is instead remarkably the same, with A-I M /A-I M being much more sensitive to proteolytic digestion (50% degraded after 10 min) than apoA-I. The identification of the proteolytic fragments by immunoblotting, N-terminal sequencing, and molecular mass determination, shows that the N-terminus of both proteins is resistant to proteolysis, with six cleavage sites located in the central and carboxy-terminal portions of the molecules. Cleavage in the middle of apoA-I occurs at dis- tinct sites in 7.8-nm (Lys 118 ) and 12.7-nm (Arg 123 ) rHDL, in- dicating a different conformation in small and large rHDL particles. The A-I M /A-I M instead adopts a unique and identi- cal conformation in small and large rHDL, with the carboxy- terminal portion of the molecule being remarkably more ac- cessible to the proteases than in apoA-I. This suggests the presence of a novel carboxy-terminal domain in A-I M /A-I M , not organized in a compact structure and not shared by wild-type apoA-I, which may account for the unique functional proper- ties of A-I M /A-I M. —Calabresi, L., G. Tedeschi, C. Treu, S. Ron- chi, D. Galbiati, S. Airoldi, C. R. Sirtori, Y. Marcel, and G. Franceschini. Limited proteolysis of a disulfide-linked apoA-I dimer in reconstituted HDL. J. Lipid Res. 2001. 42: 935-942

    One-pill once-a-day HAART: a simplification strategy that improves adherence and quality of life of HIV-infected subjects

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    OBJECTIVE: The aim of the ADONE (ADherence to ONE pill) study was to verify the effect of a reduced number of pills on adherence and quality of life (QoL) in HIV-infected patients on highly active antiretroviral therapy (HAART). DESIGN: Prospective, multicenter, study. METHODS: Patients chronically treated with emtricitabine (FTC) + tenofovir (TDF) + efavirenz (EFV) or lamivudine (3TC) +TDF +EFV and with a HIV-RNA < 50 copies/mL were switched to the single-pill fixed-dose regimen (FDR) of FTC +TDF +EFV. Data were collected with SF-36 using visual analog scales. Results of the final (6 months) primary as-treated analysis are reported. RESULTS: 212 patients (77.4% males) of mean age 45.8 years were enrolled; 202 completed the study. One month post switch to FDR the adherence rate increased significantly to 96.1% from a baseline value of 93.8% (P < 0.01). The increase was steadily maintained throughout the study (96.2% at 6 months). QoL improved over time from 68.8% to 72.7% (P = 0.042) as well, and was significantly associated with the perception of health status, presence of adverse events (AEs) and number of reported AEs (P < 0.0001). QoL significantly influenced adherence (P < 0.0001). During FDR use the mean CD4 count increased from 556 to 605 cells/muL (P < 0.0001). At the end of follow-up 98% of patients maintained HIV-RNA level < 50 copies/mL and 100% <400 copies/mL. Four patients stopped therapy because they were lost to follow-up and 6 because of AEs (insomnia/nervousness 4, allergy 1, difficulties swallowing pills 1). CONCLUSION: By substituting a one-pill once-a-day HAART, we observed an improvement of both adherence and QoL while maintaining high virologic and immunologic efficacy. HAART simplicity is an added value that favors adherence and may improve long-term success

    Loss and Recovery Potential of Marine Habitats: An Experimental Study of Factors Maintaining Resilience in Subtidal Algal Forests at the Adriatic Sea

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    BACKGROUND: Predicting and abating the loss of natural habitats present a huge challenge in science, conservation and management. Algal forests are globally threatened by loss and severe recruitment failure, but our understanding of resilience in these systems and its potential disruption by anthropogenic factors lags well behind other habitats. We tested hypotheses regarding triggers for decline and recovery potential in subtidal forests of canopy-forming algae of the genus Cystoseira. METHODOLOGY/PRINCIPAL FINDINGS: By using a combination of historical data, and quantitative in situ observations of natural recruitment patterns we suggest that recent declines of forests along the coasts of the north Adriatic Sea were triggered by increasing cumulative impacts of natural- and human-induced habitat instability along with several extreme storm events. Clearing and transplantation experiments subsequently demonstrated that at such advanced stages of ecosystem degradation, increased substratum stability would be essential but not sufficient to reverse the loss, and that for recovery to occur removal of the new dominant space occupiers (i.e., opportunistic species including turf algae and mussels) would be required. Lack of surrounding adult canopies did not seem to impair the potential for assisted recovery, suggesting that in these systems recovery could be actively enhanced even following severe depletions. CONCLUSIONS/SIGNIFICANCE: We demonstrate that sudden habitat loss can be facilitated by long term changes in the biotic and abiotic conditions in the system, that erode the ability of natural ecosystems to absorb and recover from multiple stressors of natural and human origin. Moreover, we demonstrate that the mere restoration of environmental conditions preceding a loss, if possible, may be insufficient for ecosystem restoration, and is scarcely cost-effective. We conclude that the loss of complex marine habitats in human-dominated landscapes could be mitigated with appropriate consideration and management of incremental habitat changes and of attributes facilitating system recovery

    Greening of grey infrastructure should not be used as a Trojan horse to facilitate coastal development

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    Climate change and coastal urbanization are driving the replacement of natural habitats with artificial structures and reclaimed land globally. These novel habitats are often poor surrogates for natural habitats. The application of integrated greening of grey infrastructure (IGGI) to artificial shorelines demonstrates how multifunctional structures can provide biodiversity benefits whilst simultaneously serving their primary engineering function. IGGI is being embraced globally, despite many knowledge gaps and limitations. It is a management tool to compensate anthropogenic impacts as part of the Mitigation Hierarchy. There is considerable scope for misuse and ‘greenwashing’ however, by making new developments appear more acceptable, thus facilitating the regulatory process. We encourage researchers to exercise caution when reporting on small-scale experimental trials. We advocate that greater attention is paid to when experiments ‘fail’ or yield unintended outcomes. We advise revisiting, repeating and expanding on experiments to test responses over broader spatio-temporal scales to improve the evidence base. Synthesis and applications. Where societal and economic demand makes development inevitable, particular attention should be paid to avoiding, minimizing and rehabilitating environmental impacts. Integrated greening of grey infrastructure (IGGI) should be implemented as partial compensation for environmental damage. Mutual benefits for both humans and nature can be achieved when IGGI is implemented retrospectively in previously developed or degraded environments. We caution, however, that any promise of net biodiversity gain from new developments should be scrutinized and any local ecological benefits set in the context of the wider environmental impacts. A ‘greened’ development will always impinge on natural systems, a reality that is much less recognized in the sea than on land.</p

    Ocean-related options for climate change mitigation and adaptation: A machine learning-based evidence map protocol

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    BackgroundOcean-related options (OROs) to mitigate and adapt to climate change are receiving increasing attention from practitioners, decision-makers, and researchers. In order to guide future ORO development and implementation, a catalogue of scientific evidence addressing outcomes related to different ORO types is critical. However, until now, such a synthesis has been hindered by the large size of the evidence base. Here, we detail a protocol using a machine learning-based approach to systematically map the extent and distribution of academic evidence relevant to the development, implementation, and outcomes of OROs.MethodTo produce this systematic map, literature searches will be conducted in English across two bibliographic databases using a string of search terms relating to the ocean, climate change, and OROs. A sample of articles from the resulting de-duplicated corpus will be manually screened at the title and abstract level for inclusion or exclusion against a set of predefined eligibility criteria in order to select all relevant literature on marine and coastal socio-ecological systems, the type of ORO and its outcomes. Descriptive metadata on the type and location of intervention, study methodology, and outcomes will be coded from the included articles in the sample. This sample of screening and coding decisions will be used to train a machine learning model that will be used to estimate these labels for all the remaining unseen publications. The results will be reported in a narrative synthesis summarising key trends, knowledge gaps, and knowledge clusters

    Oyster Reefs at Risk and Recommendations for Conservation, Restoration, and Management

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    Native oyster reefs once dominated many estuaries, ecologically and economically. Centuries of resource extraction exacerbated by coastal degradation have pushed oyster reefs to the brink of functional extinction worldwide. We examined the condition of oyster reefs across 144 bays and 44 ecoregions; our comparisons of past with present abundances indicate that more than 90% of them have been lost in bays (70%) and ecoregions (63%). In many bays, more than 99% of oyster reefs have been lost and are functionally extinct. Overall, we estimate that 85% of oyster reefs have been lost globally. Most of the world\u27s remaining wild capture of native oysters (\u3e 75%) comes from just five ecoregions in North America, yet the condition of reefs in these ecoregions is poor at best, except in the Gulf of Mexico. We identify many cost-effective solutions for conservation, restoration, and the management of fisheries and nonnative species that could reverse these oyster losses and restore reef ecosystem services
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