The exploitation of limpets in a Mediterranean Marine Protected Area: assessing the effectiveness of protection in the intertidal zone

Limpets are intertidal keystone grazers and their overexploitation could have significant consequences for intertidal communities. Limpets are harvested around the Sinis Peninsula (Sardinia, Italy) but harvesting is prohibited within the “Penisola del Sinis - Isola di Mal di Ventre” Marine Protected Area (MPA). This work assesses the effects of human harvesting on the population dynamics of three common Mediterranean species of Patella, namely, P. rustica, P. caerulea and P. ulyssiponensis, testing the effectiveness of the MPA and the role of site accessibility in limiting the intensity of such harvesting pressure. In the period between June 2015 and August 2016, limpet abundance and size were recorded on a monthly basis by means of photographic frames within linear transects at ten sites spread out along the coastline of the Sinis Peninsula to assess growth and temporal patterns. Limpets older than two years are extremely rare in the study area. Limpets are more abundant within the MPA in comparison with non-protected areas and within less accessible sites in comparison with areas where the intertidal zone is easily accessible from land. Despite this, overall human-induced mortality in the area is high, indeed the pool of limpets observed with a mean density of 104.3 ± 9.7 limpets/m2 during the first survey was reduced by 99.2%in less than one year. This work demonstrates that human harvesting strongly affects the population dynamics of Patella species in the area and that within the MPA this stressor is not efficiently reduced

Phthalate esters (PAEs) concentration pattern reflects dietary habitats (δ13C) in blood of Mediterranean loggerhead turtles (Caretta caretta)

Phthalic acid esters (PAEs) are classified as endocrine disruptors, but it remains unclear if they can enter the marine food-web and result in severe health effects for organisms. Loggerhead turtles (Caretta caretta) can be chronically exposed to PAEs by ingesting plastic debris, but no information is available about PAEs levels in blood, and how these concentrations are related to diet during different life stages. This paper investigated, for the first time, six PAEs in blood of 18 wild-caught Mediterranean loggerhead turtles throughout solid-phase extraction coupled with gas chromatography-ion trap/mass spectrometry. Stable isotope analyses of carbon and nitrogen were also performed to assess the resource use pattern of loggerhead turtles. DEHP (12-63 ng mL(-1)) and DBP (6-57 ng mL(-1)) were the most frequently represented PAEs, followed by DiBP, DMP, DEP and DOP. The total PAEs concentration was highest in three turtles (124-260 ng mL(-1)) whereas three other turtles had concentrations below the detection limit. PAEs were clustered in three groups according to concentration in all samples: DEHP in the first group, DBP, DEP, and DiBP in the second group, and DOP and DMP in the third group. The total phthalates concentration did not differ between large-sized (96.3 +/- 86.0 ng mL(-1)) and small-sized (67.1 +/- 34.2 ng mL(-1)) turtles (p < 0.001). However, DMP and DEP were found only in large-sized turtles and DiBP and DBP had higher concentrations in large-sized turtles. On the other hand, DEHP and DOP were found in both small- and large-sized turtles with similar concentrations, i.e. ~ 21.0/32.0 ng mL(-1) and ~ 7(.1)/9.9 ng mL(-1), respectively. Winsored robust models indicated that delta C-13 is a good predictor for DBP and DiBP concentrations (significant Akaike Information criterion weight, AIC(wt)). Our results indicate that blood is a good matrix to evaluate acute exposure to PAEs in marine turtles. Moreover, this approach is here suggested as a useful tool to explain the internal dose of PAEs in term of dietary habits (delta C-13), suggesting that all marine species at high trophic levels may be particularly exposed to PAEs, despite their different dietary habitats and levels of exposure

Nesting range expansion of loggerhead turtles in the Mediterranean: phenology, spatial distribution and conservation implications.

Global warming is affecting habitat quality and availability on our planet and some species are predicted or are by now changing their distribution range. Here we show that loggerhead turtles have already started to expand their nesting range into the Western Mediterranean, which has until recently hosted only sporadic nests. We compiled information on nesting activity from beaches surrounding the Western Mediterranean and collected metadata on loggerhead turtle nests in Spain, France, Italy, and Tunisia between 2010 and 2020 to provide an exhaustive overview on the phenomenon of emerging new nest sites for loggerhead turtles. The number of recorded nests has increased drastically since 2013 from 1 to 3 nests/year to a record number of 84 registered in 2020. While this increase may partly be explained by grown awareness and reporting by citizens, there is no doubt of an upward trend in nesting activity. The nests are unevenly distributed over the study area with most nests occurring on the coasts of the warmer Tyrrhenian Sea. A hotspot analysis identified beaches in SW Italy, SE Sardinia, and NW Tunisia with statistically significant clustering of nests. Within these hotspots, three beaches in SW Italy and one in Tunisia had nests at least four out of the five last years. Nesting phenology corresponds to that of Eastern Mediterranean rookeries, and mean hatching success of naturally incubating, non-manipulated nests was 66 %, although there was variability across the region. Mean incubation durations also varied between countries indicating a diversity in inferred sex ratios, with sufficient female production to foster future colonisation of this region. Unfortunately, these beaches are already under high tourist pressure and subject to intense coastal development, imposing many threats to the females, eggs, and hatchlings. Thus, while this study reveals the unique opportunity to witness and study an ongoing new colonisation process in loggerhead turtles, it also calls for urgent proactive conservation actions to mitigate these threats and allow the turtles to establish new rookeries

Recent Advances on the Synthesis of [4.3.0] Bicycles Featuring Three Heteroatoms Including a Bridgehead One

The manuscript details all of the relevant recent reports on the assembly of fused [4.3.0] bicycles incorporating three heteroatoms, among which one occupies a bridgehead position. Several elegant strategies have been developed as well as the application of known routes enabled a concise access to these highly functionalized scaffolds. This work presents all of these advances ordered on the basis of the structure of the desired heterocycles. Each subsection features both stoichiometric and catalytic synthetic strategies that were applied to the assembly of these compelling target

Tau Biomarkers in Dementia: Positron Emission Tomography Radiopharmaceuticals in Tauopathy Assessment and Future Perspective

Abnormal accumulation of Tau protein is closely associated with neurodegeneration and cognitive impairment and it is a biomarker of neurodegeneration in the dementia field, especially in Alzheimer’s disease (AD); therefore, it is crucial to be able to assess the Tau deposits in vivo. Beyond the fluid biomarkers of tauopathy described in this review in relationship with the brain glucose metabolic patterns, this review aims to focus on tauopathy assessment by using Tau PET imaging. In recent years, several first-generation Tau PET tracers have been developed and applied in the dementia field. Common limitations of first-generation tracers include off-target binding and subcortical white-matter uptake; therefore, several institutions are working on developing second-generation Tau tracers. The increasing knowledge about the distribution of first- and second-generation Tau PET tracers in the brain may support physicians with Tau PET data interpretation, both in the research and in the clinical field, but an updated description of differences in distribution patterns among different Tau tracers, and in different clinical conditions, has not been reported yet. We provide an overview of first- and second-generation tracers used in ongoing clinical trials, also describing the differences and the properties of novel tracers, with a special focus on the distribution patterns of different Tau tracers. We also describe the distribution patterns of Tau tracers in AD, in atypical AD, and further neurodegenerative diseases in the dementia field

Is the Loggerhead Caretta caretta a good indicator of plastic ingestion also at local scale?

The European Commission drafted the 2008/56/EC Marine Strategy Framework Directive with the aim to achieve a Good Environmental Status (GES). In 2011 Italy promoted the Loggerhead sea turtle (Caretta caretta, Linnaeus 1758) as target species for monitoring the amount and composition of litter ingested by marine animals and then it has been accepted among MSFD Indicators and under the UNEP/MAP Barcelona Convention ecological objective, at sub-regional level. 120 death loggerhead CCL ranging from 21 to 80 cm (average = 54.9 cm) have been collected stranded or by-catch along Latium and Sardinian coasts, Italy (Western Mediterranean sub-Region). Plastic ingestion has been detected with a frequency of occurrence FO=54.2%. In total, 106.138 g (dry mass) and 1103 items (abundance) of marine litter were collected with an average value of 0.892 ± 0.196 g and 9.27 ± 1.95 items. Among the impacted turtles, parts of plastic bags and other sheet fragments (USE she) were the main categories in terms of abundance (17.23 ± 3.35 items). At local level, FO%, dry mass and number of items between the two areas (Latium: FO = 79.0%, average g= 1.553 ± 0.354, average n Items = 14.76 ± 3.53; Sardinia: FO = 27.6% average g=0.173 ± 0.059, average n Items= 3.30 ± 0.95) showed significant differences and groups structure was confirmed by nonhierarchical cluster analysis. This study shows that, even if sea turtles are migratory species and marine litter move according to the current and tide, the loggerhead can give information on plastic pollution also at local scale

Functionalization of Alkenyl C–H Bonds with D2O via Pd(0)/Carboxylic Acid Catalysis

We report herein a simple catalytic method for the extensive labeling of alkenyl C–H bonds through the combination of a palladium(0) complex and a carboxylic acid in the presence of deuterium oxide. The reaction can be applied to a variety of terminal alkenes and the best results are obtained with aryl-substituted examples. This method represents a convenient approach for the preparation of extensively labeled chemicals from the cheapest and safest source of deuteriu