The Biodiversity of the Mediterranean Sea: Estimates, Patterns, and Threats

The Mediterranean Sea is a marine biodiversity hot spot. Here we combined an extensive literature analysis with expert opinions to update publicly available estimates of major taxa in this marine ecosystem and to revise and update several species lists. We also assessed overall spatial and temporal patterns of species diversity and identified major changes and threats. Our results listed approximately 17,000 marine species occurring in the Mediterranean Sea. However, our estimates of marine diversity are still incomplete as yet—undescribed species will be added in the future. Diversity for microbes is substantially underestimated, and the deep-sea areas and portions of the southern and eastern region are still poorly known. In addition, the invasion of alien species is a crucial factor that will continue to change the biodiversity of the Mediterranean, mainly in its eastern basin that can spread rapidly northwards and westwards due to the warming of the Mediterranean Sea. Spatial patterns showed a general decrease in biodiversity from northwestern to southeastern regions following a gradient of production, with some exceptions and caution due to gaps in our knowledge of the biota along the southern and eastern rims. Biodiversity was also generally higher in coastal areas and continental shelves, and decreases with depth. Temporal trends indicated that overexploitation and habitat loss have been the main human drivers of historical changes in biodiversity. At present, habitat loss and degradation, followed by fishing impacts, pollution, climate change, eutrophication, and the establishment of alien species are the most important threats and affect the greatest number of taxonomic groups. All these impacts are expected to grow in importance in the future, especially climate change and habitat degradation. The spatial identification of hot spots highlighted the ecological importance of most of the western Mediterranean shelves (and in particular, the Strait of Gibraltar and the adjacent Alboran Sea), western African coast, the Adriatic, and the Aegean Sea, which show high concentrations of endangered, threatened, or vulnerable species. The Levantine Basin, severely impacted by the invasion of species, is endangered as well

Common and rare variant association analyses in amyotrophic lateral sclerosis identify 15 risk loci with distinct genetic architectures and neuron-specific biology

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease with a lifetime risk of one in 350 people and an unmet need for disease-modifying therapies. We conducted a cross-ancestry genome-wide association study (GWAS) including 29,612 patients with ALS and 122,656 controls, which identified 15 risk loci. When combined with 8,953 individuals with whole-genome sequencing (6,538 patients, 2,415 controls) and a large cortex-derived expression quantitative trait locus (eQTL) dataset (MetaBrain), analyses revealed locus-specific genetic architectures in which we prioritized genes either through rare variants, short tandem repeats or regulatory effects. ALS-associated risk loci were shared with multiple traits within the neurodegenerative spectrum but with distinct enrichment patterns across brain regions and cell types. Of the environmental and lifestyle risk factors obtained from the literature, Mendelian randomization analyses indicated a causal role for high cholesterol levels. The combination of all ALS-associated signals reveals a role for perturbations in vesicle-mediated transport and autophagy and provides evidence for cell-autonomous disease initiation in glutamatergic neurons

Tracking Invasion Histories in the Sea: Facing Complex Scenarios Using Multilocus Data

In recent years, new analytical tools have allowed researchers to extract historical information contained in molecular data, which has fundamentally transformed our understanding of processes ruling biological invasions. However, the use of these new analytical tools has been largely restricted to studies of terrestrial organisms despite the growing recognition that the sea contains ecosystems that are amongst the most heavily affected by biological invasions, and that marine invasion histories are often remarkably complex. Here, we studied the routes of invasion and colonisation histories of an invasive marine invertebrate Microcosmus squamiger (Ascidiacea) using microsatellite loci, mitochondrial DNA sequence data and 11 worldwide populations. Discriminant analysis of principal components, clustering methods and approximate Bayesian computation (ABC) methods showed that the most likely source of the introduced populations was a single admixture event that involved populations from two genetically differentiated ancestral regions - the western and eastern coasts of Australia. The ABC analyses revealed that colonisation of the introduced range of M. squamiger consisted of a series of non-independent introductions along the coastlines of Africa, North America and Europe. Furthermore, we inferred that the sequence of colonisation across continents was in line with historical taxonomic records - first the Mediterranean Sea and South Africa from an unsampled ancestral population, followed by sequential introductions in California and, more recently, the NE Atlantic Ocean. We revealed the most likely invasion history for world populations of M. squamiger, which is broadly characterized by the presence of multiple ancestral sources and non-independent introductions within the introduced range. The results presented here illustrate the complexity of marine invasion routes and identify a cause-effect relationship between human-mediated transport and the success of widespread marine non-indigenous species, which benefit from stepping-stone invasions and admixture processes involving different sources for the spread and expansion of their range

Efficiency of pivot splints as jaw exercise apparatus in combination with stabilization splints in anterior disc displacement without reduction: a retrospective study

Objective: To evaluate efficiency of pivot splints in jaw exercises, in combination with stabilization splints, in cases of anterior disc displacement without reduction of temporomandibular joint. Subjects and methods: Twenty-three patients who referred to the prosthodontics clinic in 1995-1997 were included in the study, where anterior disc displacement without reduction of temporomandibular joint was diagnosed using magnetic resonance imaging and clinical examination. Pivot splints were used for jaw exercises for five minutes long; five times/day and stabilization splints were used at all other times. The patients were followed for 24 weeks. Lateral and protrusive excursions along with maximum mouth opening and were evaluated at each control. Bilateral palpation of temporal, masseter, sternocleidomastoid muscles and TMJ was assessed for pain perception before and after treatment. Data were statistically analyzed using Paired sample t-test and Independent Samples t-test (p < .05). Results: Mean mandibular range of motion measurements increased from 28.74 mm prior to 49.17 mm on maximum opening; right/left lateral excursion from 7.61 mm to 12.04 mm and 4.09 mm to 7.3 mm on protrusion after treatment. All changes observed before and after treatment were found to be statistically significant. (p < .001) Pain symptoms were eliminated at the end of 24 weeks of treatment in all patients. Conclusion: Using pivot splints as an exercise regimen along with a stabilization splint may be a viable treatment option for patients with anterior disc displacement without reduction; as normal mandibular range of motion was established and pain was eliminated

The Demography of Obesity

A steady rise in obesity prevalence over several decades has led to considerable scholarly interest in its causes and consequences. Demographers have contributed a great deal to this body of research by examining variations within and across populations, establishing its link to mortality and morbidity, providing forecast and projections of future levels, and considering how its’ presence is variable by demographic characteristics. This chapter begins with a review of overall global trends in obesity and a discussion of the evolution of research on this topic – including background on the measures used to track obesity prevalence. Next, it offers a summary of how obesity varies by key demographic variables, followed by a discussion of its health and social consequences. Population shifts that contribute to increased obesity prevalence are considered next. The chapter concludes with methodological approaches and challenges, as well as future research directions