Biomass HotSpot distribution model and spatial interaction of two exploited species of horse mackerel in the south-central Mediterranean Sea

Trachurus trachurus and Trachurus mediterraneus play an important role in the marine ecosystem and represent an important source of income for local economies related to fishery. This study aimed to improve the knowledge on the spatial distribution and habitat requirements of these two horse mackerels in the south-central Mediterranean Sea (Strait of Sicily) by applying specie distribution models. Species’ biomass HotSpots, areas where the highest abundances are concentrated, were modelled as a function of physical and oceanographic parameters. Predictive distribution maps were produced to identify species-specific spatial patterns and possible overlapping in the distribution areas of the two congeneric species. Depth, bottom salinity, bottom sea temperature, sea surface temperature variation and slope were the main drivers for horse mackerels habitat suitability. Predictive distribution maps revealed a clear spatial segregation between biomass HotSpots of the two species, which depends on complex abiotic and biotic relationships. Since horse mackerels are the main component of discards produced by deep rose shrimp fishery in the Strait of Sicily and due to the importance of discard reduction in the current fishery policies, the results can provide important information for setting up spatial-based management strategies for the Strait of Sicily fisheries aimed in particular at minimizing unwanted by-catches.     

Identification of first-stage dorsal-spined lungworm larvae of Tunisian barbary red deer: First report of Varestrongylus sagittatus and Elaphostrongylus cervi in Africa

Barbary red deer (Cervus elaphus barbarus) is a protected rare subspecies of red deer. The study of its Protostrongylidae fauna based only on sporadic necropsy of naturally dead animals is difficult. Therefore diagnosis of lungworms rely mainly on the identification of the first stage larvae (L1). The L1 of the different species are not readily diagnosed on morphological basis since much variation is recorded within and among dorsal-spined larvae belonging to various species. The aim of this study was to identify the dorsal-spined lungworm larvae of the Barbary red deer. A discriminant function was established, using the measurements of L1 lungworms recorded from red deer in the literature, then applied to identify 220 dorsal-spined larvae extracted from 25 Tunisian Barbary red deer fresh fecal samples. Also the ITS2 region of rDNA of four pools of larvae (n?=?25–60) were amplified, sequenced and analyzed. Using discriminant analysis of morphological traits, Elaphostrongylus cervi and Varestongylus sagittatus were identified. Molecular identification confirmed the presence of E. cervi which is the most prevalent species. This study represents the first identification of V. sagittatus and E. cervi in North Africa.     

Synthesis and evaluation of 5-(1H-indol-3-yl)-N-aryl-1,3,4-oxadiazol-2-amines as Bcl-2 inhibitory anticancer agents

A series of 5-(1H-indol-3-yl)-N-aryl-1,3,4-oxadiazol-2-amines 8a–j has been designed, synthesized and tested in vitro as potential pro-apoptotic Bcl-2-inhibitory anticancer agents based on our previous lead compound 8a. Synthesis of the target compounds was readily accomplished through a cyclisation reaction between indole-3-carboxylic acid hydrazide (5) and substituted isothiocyanates 6a–j, followed by oxidative cyclodesulfurization of the corresponding thiosemicarbazide 7a–j using 1,3-dibromo-5,5-dimethylhydantoin. Active compounds of the series 8a–j were found to have sub-micromolar IC₅₀ values selectively in Bcl-2 expressing human cancer cell lines; notably the 2-nitrophenyl analogue 8a was found to exhibit potent activity, and compounds 8a and 8e possessed comparable Bcl-2 binding affinity (ELISA assay) to the established natural product-based Bcl-2 inhibitor, gossypol. Molecular modeling studies helped to further rationalise anti-apoptotic Bcl-2 binding, and identified compounds 8a and 8e as candidates for further development as Bcl-2 inhibitory anticancer agents.     

Downstream flow and upstream movement determine the value of a stream reach for potadromous fish populations

Given that human activities often have negative impacts on biological populations, a common question is to find the location of greatest positive or least negative impact. Local habitat suitability is frequently used to evaluate viability of fish populations in river networks. Upper stream reaches are often undervalued, in particular when they are not navigable or do not contain commercially interesting fish. Since water flow transports certain local conditions downstream and individuals navigate river networks upstream and downstream, impacts of local perturbations can manifest elsewhere in the system, and overall effects of disturbances should be assessed on a network level. We study a model for a potadromous fish population in a system of connected stream reaches. We consider different geometries to evaluate how downstream transport and individual movement interact to determine the location of greatest and least impact of a single or two concurrent disturbances. Our results show how upper stream reaches can be highly significant for population persistence if downstream transport of abiotic conditions or upstream movement of individuals is strong.     

Antibacterial and Anticancer activity of ε -poly-L-lysine (ε -PL) produced by a marine Bacillus subtilis sp

A marine Bacillus subtilis SDNS was isolated from sea water in Alexandria and identified using 16S rDNA sequence analysis. The bacterium produced a compound active against a number of gram negativeve bacteria. Moreover, the anticancer activity of this bacterium was tested against three different human cell lines (Hela S3, HepG2 and CaCo). The highest inhibition activity was recorded against Hela S3 cell line (77.2%), while almost no activity was recorded towards CaCo cell line. HPLC and TLC analyses supported evidence that Bacillus subtilis SDNS product is ?;-poly-L-lysine. To achieve maximum production, Plackett-Burman experimental design was applied. A 1.5 fold increase was observed when Bacillus subtilis SDNS was grown in optimized medium composed of g/l: (NH(4) )(2) SO(4) , 15; K(2) HPO(4) , 0.3; KH(2) PO(4) , 2; MgSO(4) · 7 H(2) O, 1; ZnSO(4) · 7 H(2) O, 0; FeSO(4) · 7 H(2) O, 0.03; glucose, 25; yeast extract, 1, pH 6.8. Under optimized culture condition, a product value of 76.3 mg/l could be obtained. According to available literature, this is the first announcement for the production of ?;-poly-L-lysine (?;-PL) by a member of genus Bacillus. (? 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim).     

The differential NF-kB modulation by S-adenosyl-L-methionine,N-acetylcysteine and quercetin on the promotion stage of chemical hepatocarcinogenesis

S-adenosylmethionine (SAM), N-acetylcysteine (NAC) and quercetin exhibit a chemoprotective effect. Likely this effect is mediated by counteracting, oxidative stress and NF-kB activation. To test this hypothesis F344 rats were subjected to hepatocarcinogenesis with or without antioxidants. NAC decreased foci in number and area, SAM and quercetin decreased area. Lipid-peroxidation was decreased by antioxidants, but only SAM increased glutathione. SAM, in its regulation from IKK downwards, abolished the NF-kB activation. NAC decreased IKK and IkB-a phosphorylation, and Rel-A/p65 and NF-kB binding, though the last two were affected with less intensity compared to the NF-kB inhibitor. Quercetin decreased Rel-A/p65, without modifying upstream signalling. Although all antioxidants inhibited oxidative stress as shown by reduction of lipid peroxidation, not all exerted the same effect on NF-kB signalling pathway and only SAM increased GSH. The mechanisms exerted by SAM in the reduction of foci makes this compound a potential liver cancer therapeutic agent.     

In-Situ Determination of the Mechanical Properties of Gliding or Non-Motile Bacteria by Atomic Force Microscopy under Physiological Conditions without Immobilization

We present a study about AFM imaging of living, moving or self-immobilized bacteria in their genuine physiological liquid medium. No external immobilization protocol, neither chemical nor mechanical, was needed. For the first time, the native gliding movements of Gram-negative Nostoc cyanobacteria upon the surface, at speeds up to 900 µm/h, were studied by AFM. This was possible thanks to an improved combination of a gentle sample preparation process and an AFM procedure based on fast and complete force-distance curves made at every pixel, drastically reducing lateral forces. No limitation in spatial resolution or imaging rate was detected. Gram-positive and non-motile Rhodococcus wratislaviensis bacteria were studied as well. From the approach curves, Young modulus and turgor pressure were measured for both strains at different gliding speeds and are ranging from 20±3 to 105±5 MPa and 40±5 to 310±30 kPa depending on the bacterium and the gliding speed. For Nostoc, spatially limited zones with higher values of stiffness were observed. The related spatial period is much higher than the mean length of Nostoc nodules. This was explained by an inhomogeneous mechanical activation of nodules in the cyanobacterium. We also observed the presence of a soft extra cellular matrix (ECM) around the Nostoc bacterium. Both strains left a track of polymeric slime with variable thicknesses. For Rhodococcus, it is equal to few hundreds of nanometers, likely to promote its adhesion to the sample. While gliding, the Nostoc secretes a slime layer the thickness of which is in the nanometer range and increases with the gliding speed. This result reinforces the hypothesis of a propulsion mechanism based, for Nostoc cyanobacteria, on ejection of slime. These results open a large window on new studies of both dynamical phenomena of practical and fundamental interests such as the formation of biofilms and dynamic properties of bacteria in real physiological conditions.