The Mediterranean Sea under siege: spatial overlap between marine biodiversity,cumulative threats and marine reserves

Aim A large body of knowledge exists on individual anthropogenic threats that have an impact on marine biodiversity in the Mediterranean Sea, although we know little about how these threats accumulate and interact to affect marine species and ecosystems. In this context, we aimed to identify the main areas where the interaction between marine biodiversity and threats is more pronounced and to assess their spatial overlap with current marine protected areas in the Mediterranean. Location Mediterranean Sea. Methods We first identified areas of high biodiversity of marine mammals, marine turtles, seabirds, fishes and commercial or well‐documented invertebrates. We mapped potential areas of high threat where multiple threats are occurring simultaneously. Finally we quantified the areas of conservation concern for biodiversity by looking at the spatial overlap between high biodiversity and high cumulative threats, and we assessed the overlap with protected areas. Results Our results show that areas with high marine biodiversity in the Mediterranean Sea are mainly located along the central and north shores, with lower values in the south‐eastern regions. Areas of potential high cumulative threats are widespread in both the western and eastern basins, with fewer areas located in the south‐eastern region. The interaction between areas of high biodiversity and threats for invertebrates, fishes and large animals in general (including large fishes, marine mammals, marine turtles and seabirds) is concentrated in the coastal areas of Spain, Gulf of Lions, north‐eastern Ligurian Sea, Adriatic Sea, Aegean Sea, south‐eastern Turkey and regions surrounding the Nile Delta and north‐west African coasts. Areas of concern are larger for marine mammal and seabird species. Main conclusions These areas may represent good candidates for further research, management and protection activities, since there is only a maximum 2% overlap between existing marine protected areas (which cover 5% of the Mediterranean Sea) and our predicted areas of conservation concern for biodiversity.     

Immune opsonins modulate BLyS/BAFF release in a receptor-specific fashion

TNF ligand superfamily member 13B (B lymphocyte stimulator (BLyS), B cell activating factor (BAFF)) promotes primary B cell proliferation and Ig production. While the soluble form of BLyS/BAFF is thought to be the primary biologically active form, little is known about the regulation of its cleavage and processing. We provide evidence that Fcgamma receptor cross-linking triggers a rapid release of soluble, biologically active BLyS/BAFF from myeloid cells. Surprisingly, this function is primarily mediated by FcgammaRI, but not FcgammaRIIa as defined by specific mAb, and can be initiated by both IgG and C reactive protein as ligands. The generation of a B cell proliferation and survival factor by both innate and adaptive immune opsonins through engagement of an Fcgamma receptor, which can also enhance Ag uptake and presentation, provides a unique opportunity to facilitate Ab production. These results provide a mechanism by which Fcgamma receptors can elevate circulating BLyS levels and promote autoantibody production in immune complex-mediated autoimmune diseases.     

Phenotypic characteristics of coliform and noncoliform bacteria from a public water supply compared with regional and national clinical species

During the summer and fall of 1984, elevated total coliform counts were observed in the distribution system of a public water supply serving 350,000 people in south central Connecticut. As part of an investigation of possible health risks associated with the presence of bacteria in the water supply, bacterial isolates from the distribution system were compared with bacterial isolates of the same species obtained from a large regional teaching hospital and from a national compendium of clinical isolates. Characteristics analyzed included phenotypic metabolic activity, antimicrobial susceptibilities to clinically utilized antibiotics, temperature tolerance at 44.5 degrees C, and beta-glucuronidase activity in single-test form and on a selective medium. Environmental isolates lacked known plasmid-mediated characteristics, with the exception of one Escherichia coli isolate which showed some antibiotic resistance. Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter cloacae, and Enterobacter agglomerans from all sources were temperature tolerant and yielded positive fecal coliform tests. Only E. coli showed beta-glucuronidase activity (both in a single biochemical test and on a selective medium). No single characteristic analyzed was sufficient to establish an organism as either environmental or clinical in origin.     

An animal model of Curvularia geniculata and its relationship with human disease

The conidiospore of Curvularia geniculata was observed in the bronchial washings of a patient who subsequently developed pulmonary aspergillosis. Curvularia geniculata was grown in culture and used in experiments in mice to explore its possible role as a disease causing agent. The fungus, after intraperitoneal injection, produced granulomas in the liver and spleen. Studies on the pathogenicity of this fungus in mice produced similar lesions to those observed in the human case. A comparison of the lesions in the patient's lung and in the animal experimental model is presented.     

Efficacy of beta-glucuronidase assay for identification of Escherichia coli by the defined-substrate technology

In 1976, Kilian and Bulow described the association of beta-glucuronidase with the genus Escherichia (97% positive) and suggested that a beta-glucuronidase assay would be a useful identification test. Since that report, papers about the sensitivity and specificity of this enzyme for the identification of Escherichia coli from clinical sources, food, seawater, potable-water supplies, and various environmental sources have appeared. A study was undertaken to determine the efficacy and specificity of the defined-substrate technology beta-glucuronidase (Colilert) assay for the identification of this species from fecal samples. A total of 460 human, 105 cow, and 55 horse E. coli isolates were tested. Results showed 95.5% beta-glucuronidase-positive isolates in 24 h and 99.5% positive after 28 h of incubation. Only one E. coli isolate was negative. There were no significant differences in the percentage of beta-glucuronidase-positive isolates among the human or animal isolates. There were no non-E. coli isolates that were positive. All subjects carried beta-glucuronidase-positive E. coli.     

Methylation of satellite deoxyribonucleic acid in mouse neoplastic and non-neoplastic cell cultures

Summary Comparisons of nucleic acid methylation between paired neoplastic and non-neoplastic mouse cell lines have shown a striking difference in the deoxyribonucleic acid (DNA) peak eluted from methylated albumin-kieselguhr columns (R. Gantt and V. J. Evans, 1969, Cancer Res. 29: 536–541). Since mouse satellite DNA is relatively highly methylated, its 5-methylcytosine content was compared with mainband DNA in these two paired cell lines to determine whether this might account for the observed differences. The cell DNA was labeled with methyl-labeled methionine and isolated from the cells by repeated neutral cesium chloride isopycnic centrifugation. The satellite DNA strands were then separated in an alkaline cesium chloride gradient. Both the 5-methylcytosine content and the relative amounts of satellite DNA were indistinguishable in the paired cell lines. Further, the results showed that both strands of satellite DNA had virtually equal amounts of 5-methylcytosine, although the heavy strand contains 1.5 times more cytosine than the light strand.     

The maintenance of hybrids by parasitism in a freshwater snail

Hybrids have often been labelled evolutionary dead-ends due to their lower fertility and viability. However, there is growing awareness that hybridisation between different species may play a constructive role in animal evolution as a means to create variability. Thus, hybridisation and introgression may contribute to adaptive evolution, for example with regards to natural antagonists (parasites, predators, competitors) and adaptation to local environmental conditions. Here we investigated whether parasite intensity contributes to the continuous recreation of hybrids in 74 natural populations of Melanopsis, a complex of freshwater snails with three species. We also examined, under laboratory conditions, whether hybrids and their parental taxa differ in their tolerance of low and high temperatures and salinity levels. Infections were consistently less prevalent in males than in females, and lower in snails from deeper habitats. Infection prevalence in hybrids was significantly lower than in the parental taxa. Low hybrid infection rates could not be explained by sediment type, snail density or geographic distribution of the sampling sites. Interestingly, infected hybrid snails did not show signs of parasite-induced gigantism, whereas all parental taxa did. We found that hybrids mostly coped with extreme temperatures and salinity levels as well as their parental taxa did. Taken together, our results suggest that Melanopsis hybrids perform better in the presence of parasites and environmental stress. This may explain the widespread and long-term occurrence of Melanopsis hybrids as evidenced by paleontological and biogeographic data. Hybridisation may be an adaptive host strategy, reducing infection rates and resisting gigantism.     

Estimation of daily energy expenditure in pregnant and non-pregnant women using a wrist-worn tri-axial accelerometer

Background

Few studies have compared the validity of objective measures of physical activity energy expenditure (PAEE) in pregnant and non-pregnant women. PAEE is commonly estimated with accelerometers attached to the hip or waist, but little is known about the validity and participant acceptability of wrist attachment. The objectives of the current study were to assess the validity of a simple summary measure derived from a wrist-worn accelerometer (GENEA, Unilever Discover, UK) to estimate PAEE in pregnant and non-pregnant women, and to evaluate participant acceptability.

Methods

Non-pregnant (N = 73) and pregnant (N = 35) Swedish women (aged 20–35 yrs) wore the accelerometer on their wrist for 10 days during which total energy expenditure (TEE) was assessed using doubly-labelled water. PAEE was calculated as 0.9×TEE-REE. British participants (N = 99; aged 22–65 yrs) wore accelerometers on their non-dominant wrist and hip for seven days and were asked to score the acceptability of monitor placement (scored 1 [least] through 10 [most] acceptable).

Results

There was no significant correlation between body weight and PAEE. In non-pregnant women, acceleration explained 24% of the variation in PAEE, which decreased to 19% in leave-one-out cross-validation. In pregnant women, acceleration explained 11% of the variation in PAEE, which was not significant in leave-one-out cross-validation. Median (IQR) acceptability of wrist and hip placement was 9(8–10) and 9(7–10), respectively; there was a within-individual difference of 0.47 (p<.001).

Conclusions

A simple summary measure derived from a wrist-worn tri-axial accelerometer adds significantly to the prediction of energy expenditure in non-pregnant women and is scored acceptable by participants.     

Sandhoff disease in Argentina: high frequency of a splice site mutation in the HEXB gene and correlation between enzyme and DNA-based tests for heterozygote detection

The level of -hexosaminidase activity in plasma and leukocytes and the frequency of three known HEXB mutations were studied in an Argentinean deme with high incidence of infantile Sandhoff disease. Two mutations were previously identified in one of two Sandhoff patients from the region, a splice mutation, IVS-2+1 GA, and a 4-bp deletion, CTTT_782–785. These mutations, and a 16kb deletion from the 5' end of the HEXB gene common in non-Argentineans, were screened in 9 Sandhoff patients (all unrelated), 24 obligate heterozygotes, 33 additional individuals belonging to families with affected members, and 64 randomly ascertained individuals from the high risk region. Of 31 independent alleles examined, including those of the two patients previously reported, 30 had the IVS-2 splice mutation and only the originally reported patient had the CTTT deletion. The 16-kb deletion was not observed. Further, among the 57 unaffected members of families with a previous history of Sandhoff disease, and absolute correlation was found between carrier diagnosis by enzyme assay of leukocytes and the DNA-based tests for mutation. One of the 64 controls was classified as a carrier by enzyme assay but did not have one of the three mutations screened. We conclude that a single mutation predominates in this Argentinean population and that the DNA-based test can be an effective supplement or alternative to enzyme-based testing.