Permanent draft genome sequence of Frankia sp. NRRL B-16219 reveals the presence of canonical nod genes, which are highly homologous to those detected in Candidatus Frankia Dg1 genome

Frankia sp. NRRL B-16219 was directly isolated from a soil sample obtained from the rhizosphere of Ceanothus jepsonii growing in the USA. Its host plant range includes members of Elaeagnaceae species. Phylogenetically, strain NRRL B-16219 is closely related to “Frankia discariae” with a 16S rRNA gene similarity of 99.78%. Because of the lack of genetic tools for Frankia, our understanding of the bacterial signals involved during the plant infection process and the development of actinorhizal root nodules is very limited. Since the first three Frankia genomes were sequenced, additional genome sequences covering more diverse strains have helped provide insight into the depth of the pangenome and attempts to identify bacterial signaling molecules like the rhizobial canonical nod genes. The genome sequence of Frankia sp. strain NRRL B-16219 was generated and assembled into 289 contigs containing 8,032,739 bp with 71.7% GC content. Annotation of the genome identified 6211 protein-coding genes, 561 pseudogenes, 1758 hypothetical proteins and 53 RNA genes including 4 rRNA genes. The NRRL B-16219 draft genome contained genes homologous to the rhizobial common nodulation genes clustered in two areas. The first cluster contains nodACIJH genes whereas the second has nodAB and nodH genes in the upstream region. Phylogenetic analysis shows that Frankia nod genes are more deeply rooted than their sister groups from rhizobia. PCR-sequencing suggested the widespread occurrence of highly homologous nodA and nodB genes in microsymbionts of field collected Ceanothus americanus

Contrasted Reactivity to Oxygen Tensions in Frankia sp. Strain CcI3 throughout Nitrogen Fixation and Assimilation

Reconciling the irreconcilable is a primary struggle in aerobic nitrogen-fixing bacteria. Although nitrogenase is oxygen and reactive oxygen species-labile, oxygen tension is required to sustain respiration. In the nitrogen-fixing Frankia, various strategies have been developed through evolution to control the respiration and nitrogen-fixation balance. Here, we assessed the effect of different oxygen tensions on Frankia sp. strain CcI3 growth, vesicle production, and gene expression under different oxygen tensions. Both biomass and vesicle production were correlated with elevated oxygen levels under both nitrogen-replete and nitrogen-deficient conditions. The mRNA levels for the nitrogenase structural genes (nifHDK) were high under hypoxic and hyperoxic conditions compared to oxic conditions. The mRNA level for the hopanoid biosynthesis genes (sqhC and hpnC) was also elevated under hyperoxic conditions suggesting an increase in the vesicle envelope. Under nitrogen-deficient conditions, the hup2 mRNA levels increased with hyperoxic environment, while hup1 mRNA levels remained relatively constant. Taken together, these results indicate that Frankia protects nitrogenase by the use of multiple mechanisms including the vesicle-hopanoid barrier and increased respiratory protection

Sezonska pojava i histopatologija parazita Trichodina puytoraci Lom, 1962 na ciplu glavašu (Mugil cephalus) iz Tunisa

During a parasitological survey in Ghar El Melh Lagoon in Tunisia, 108 flathead mullet (Mugil cephalus L., 1758) were investigated for protozoan ectoparasites. Trichodina puytoraci Lom, 1962 infecting the gills of the examined fish were isolated and reported for the first time from this locality. The overall infestation prevalence and mean intensity level were 22.42 % and 70 ± 8.1 trichodinids per fish, respectively. The highest prevalence was observed in spring. The relationship between host’s size and parasite prevalence was significant. The histopathological study revealed that M. cephalus heavily infested by T. puytoraci exhibited serious lesions such as hyperplasia of the epithelial cells, fusion and necrosis of secondary lamellae.Tijekom parazitološkog pregleda 108 primjeraka cipla glavaša (Mugil cephalus L., 1758) u Ghar El Melh Laguna u Tunisu, istraživani su ektoparaziti iz grupe protozoa. Škrge pregledanih riba bile su zaražene s parazitom Trichodina puytoraci Lom, 1962 koji je izoliran i utvrđen po prvi put za ovaj lokalitet. Ustanovljena je ukupna prevalencija zaraze (22,42%) i srednja razina intenziteta (70 ± 8,1) trichodinida po primjerku. Najveća prevalencija uočena je u proljeće. Odnos između veličine domaćina i rasprostranjenosti nametnika je bio značajan. Histopatološka studija otkrila je da je cipal glavaš, M. cephalus, teško zaražen parazitom T. puytoraci, izložen ozbiljnim promjenama kao što su hiperplazija epitelnih stanica te spajanje i nekroza sekundarnih lamela

Hatching Strategies in Monogenean (Platyhelminth) Parasites that Facilitate Host Infection

In parasites, environmental cues may influence hatching of eggs and enhance the success of infections. The two major endoparasitic groups of parasitic platyhelminths, cestodes (tapeworms) and digeneans (flukes), typically have high fecundity, infect more than one host species, and transmit trophically. Monogeneans are parasitic flatworms that are among the most host specific of all parasites. Most are ectoparasites with relatively low fecundity and direct life cycles tied to water. They infect a single host species, usually a fish, although some are endoparasites of amphibians and aquatic chelonian reptiles. Monogenean eggs have strong shells and mostly release ciliated larvae, which, against all odds, must find, identify, and infect a suitable specific host. Some monogeneans increase their chances of finding a host by greatly extending the hatching period (possible bet-hedging). Others respond to cues for hatching such as shadows, chemicals, mechanical disturbance, and osmotic changes, most of which may be generated by the host. Hatching may be rhythmical, larvae emerging at times when the host is more vulnerable to invasion, and this may be combined with responses to other environmental cues. Different monogenean species that infect the same host species may adopt different strategies of hatching, indicating that tactics may be more complex than first thought. Control of egg assembly and egg-laying, possibly by host hormones, has permitted colonization of frogs and toads by polystomatid monogeneans. Some monogeneans further improve the chances of infection by attaching eggs to the host or by retaining eggs on, or in, the body of the parasite. The latter adaptation has led ultimately to viviparity in gyrodactylid monogeneans

Biología reproductiva de Diplodus sargus sargus en el golfo de Túnez (Mediterráneo)

The sexual activity of Diplodus sargus sargus in the Gulf of Tunis takes place from January to May. Spawning occurs in spring (March to May), as the water temperature rises from 15 to 18°C, just after the winter minimum. The spawning period increases as the latitude decreases. The overall male to female ratio was statistically different from unity. Size at sexual maturity (TL50) was 21 cm (4 years old). The length-weight relationship for all individuals was described by the following parameters: a = 0.015 and b = 3.051. D. s. sargus from the Gulf of Tunis is a rudimentary hermaphrodite with partial protandry.La actividad sexual de Diplodus sargus sargus del golfo de Túnez tiene lugar de enero a mayo. La puesta tiene lugar en primavera (marzo a mayo), cuando la temperatura del agua sube de 15 a 18°C, justo tras el mínimo invernal. A medida que la latitud decrece se observa un periodo reproductivo progresivamente más extenso. La relación machos/hembras fue significativamente distinta de uno. La talla de madurez sexual (TL50) fue 21 cm (4 años). La relación talla-peso para todos los individuos se describió por los siguientes parámetros: a = 0.015 y b = 3.051. D. s. sargus del golfo de Túnez es un a hermafrodita rudimentario con proterandría parcial.

Structural Study of the Compound [(C10O8H2)2 (C4N2H6)].2H2O Synthesized by Hydrothermal Condition

A new metal–organic compound [(C10O8H2)2(C4N2H6)].2H2O(I) was hydrothermally synthesized from an aqueous solution of Fe (NO3)3 9H2O, (btec) (btec= 1, 2, 4, 5-benzenetetracarboxylic acid) and piperazine. Compound I crystallizes in the triclinic system with the P1 space group. The unit cell parameters are a = 8.271 Å, b = 8.500 Å, c = 9.660 Å, α = 87.12°, β = 89.53°, γ = 70.91°, Z= 2, V= 640.96(6) Å3 and Dx= 1.602g/cm3. The refinement converged into R= 0.047 and RW = 0.059. The structure, determined by single crystal X-ray diffraction, consists of two carboxyl group, piperazine and two molecules of water

Emotional Integration and Advertising Effectiveness:Case of Perfumes Advertising

This paper examines emotions in advertising, its effects and functioning. Using an interview-based experiment on 256 participants, we found that emotions perceived during an advertising exposure could play an important role in eliciting responses towards the ad and the brand. However, this process is true provided that consumers associate the perceived emotion to the exposed brand or its consumption experience. Furthermore, we have identified efficiency differences between magazine ads, depending on how they visually describe emotions. In particular, we study emotional integration in advertising, i.e. salience of emotions expressed towards the ad, the presence of core brand information and clarity of the advertising message about the hedonic attributes of consumption. Interestingly, the impact of the staging process of emotions is moderated by respondents-specific variables, including their need for emotion, tolerance for ambiguity, their need for structure and need for cognition

Bridging FEM and Artificial Neural Network in gating system design for smart 3D sand casting

A relatively new methodology bridging FEM and Artificial Neural Network (ANN) is proposed and validated in this study to optimize the gating system design for smart 3D sand casting. This methodology was applied on the case of 3D sand casting of a simple plate with aluminum alloy (EN AC-44200). Several mold-filling simulations are performed with the commercial FE code ProCast® by using a combination of the studied gating system design parameters, selected from Taguchi orthogonal array. Signal to noise (S/N) ratio and analysis of variance (ANOVA) are then employed to analyze the contributions of the studied design parameters on the molten metal velocity at the ingate. The significant parameters and their corresponding FE simulations are used to train and validate the ANN model. It is found that ANN simulator can rapidly predict the ingate velocity for any combination of the significant gating system design parameters covering the studied design space

Draft genome sequence of Frankia sp. strain BMG5.23, a salt-tolerant nitrogen-fixing actinobacterium isolated from the root nodules of Casuarina glauca grown in Tunisia

Nitrogen-fixing actinobacteria of the genus Frankia are symbionts of woody dicotyledonous plants termed actinorhizal plants. We report here a 5.27-Mbp draft genome sequence for Frankia sp. strain BMG5.23, a salt-tolerant nitrogen-fixing actinobacterium isolated from root nodules of Casuarina glauca collected in Tunisia