Superior Mesenteric Artery originating from the celiac axis: A rare vascular anomaly

The knowledge of the vascular anatomy of the concerned region is an important prerequisite for planning surgical intervention. The awareness of the existing vascular anomalies enhances the insight regarding that region. We report a patient undergoing preoperative evaluation with CTA finding of Superior Mesenteric Artery (SMA) originating from the celiac artery. This celiac-mesenteric trunk is rare (<1%)

Trajectory studies of Polar Statospheric Cloud Lidar Observations at Sodankyla (Finland) during SESAME: comparison with box model results of particle evolution

Polar statospheric clouds (PSC) were observed with the milti-wavelengh lidar of the MOANA project during SESAME. The physical state, liquid or solid, of the cloud particles can be inferred from the lidar data. Using isentropic back-trajectories to obtain the thermal history of the sampled air masses, it is possible to reconcile most of the observations with current ideas on PSC formation and evolution. When the cloud particles were identified as liquid, changes in the size distributionof the droplets along the trajectory ewre calculated using micro-physical box model. Backscatter ratios ......Published165-1811.8. Osservazioni di geofisica ambientaleJCR Journalreserve

The influence of the accessory genome on bacterial pathogen evolution

Bacterial pathogens exhibit significant variation in their genomic content of virulence factors. This reflects the abundance of strategies pathogens evolved to infect host organisms by suppressing host immunity. Molecular arms-races have been a strong driving force for the evolution of pathogenicity, with pathogens often encoding overlapping or redundant functions, such as type III protein secretion effectors and hosts encoding ever more sophisticated immune systems. The pathogens’ frequent exposure to other microbes, either in their host or in the environment, provides opportunities for the acquisition or interchange of mobile genetic elements. These DNA elements accessorise the core genome and can play major roles in shaping genome structure and altering the complement of virulence factors. Here, we review the different mobile genetic elements focusing on the more recent discoveries and highlighting their role in shaping bacterial pathogen evolution

Chromosomal-level assembly of the Asian Seabass genome using long sequence reads and multi-layered scaffolding

We report here the ~670 Mb genome assembly of the Asian seabass (Lates calcarifer), a tropical marine teleost. We used long-read sequencing augmented by transcriptomics, optical and genetic mapping along with shared synteny from closely related fish species to derive a chromosome-level assembly with a contig N50 size over 1 Mb and scaffold N50 size over 25 Mb that span ~90% of the genome. The population structure of L. calcarifer species complex was analyzed by re-sequencing 61 individuals representing various regions across the species' native range. SNP analyses identified high levels of genetic diversity and confirmed earlier indications of a population stratification comprising three clades with signs of admixture apparent in the South-East Asian population. The quality of the Asian seabass genome assembly far exceeds that of any other fish species, and will serve as a new standard for fish genomics

Stability, Entrapment and Variant Formation of Salmonella Genomic Island 1

<div><h3>Background</h3><p>The <em>Salmonella</em> genomic island 1 (SGI1) is a 42.4 kb integrative mobilizable element containing several antibiotic resistance determinants embedded in a complex integron segment In104. The numerous SGI1 variants identified so far, differ mainly in this segment and the explanations of their emergence were mostly based on comparative structure analyses. Here we provide experimental studies on the stability, entrapment and variant formation of this peculiar gene cluster originally found in <em>S</em>. Typhimurium.</p> <h3>Methodology/Principal Findings</h3><p>Segregation and conjugation tests and various molecular techniques were used to detect the emerging SGI1 variants in <em>Salmonella</em> populations of 17 <em>Salmonella enterica</em> serovar Typhimurium DT104 isolates from Hungary. The SGI1s in these isolates proved to be fully competent in excision, conjugal transfer by the IncA/C helper plasmid R55, and integration into the <em>E. coli</em> chromosome. A trap vector has been constructed and successfully applied to capture the island on a plasmid. Monitoring of segregation of SGI1 indicated high stability of the island. SGI1-free segregants did not accumulate during long-term propagation, but several SGI1 variants could be obtained. Most of them appeared to be identical to SGI1-B and SGI1-C, but two new variants caused by deletions via a short-homology-dependent recombination process have also been detected. We have also noticed that the presence of the conjugation helper plasmid increased the formation of these deletion variants considerably.</p> <h3>Conclusions/Significance</h3><p>Despite that excision of SGI1 from the chromosome was proven in SGI1⁺<em>Salmonella</em> populations, its complete loss could not be observed. On the other hand, we demonstrated that several variants, among them two newly identified ones, arose with detectable frequencies in these populations in a short timescale and their formation was promoted by the helper plasmid. This reflects that IncA/C helper plasmids are not only involved in the horizontal spreading of SGI1, but may also contribute to its evolution.</p> </div

Microlayers of solid particles observed by lidar at Sodankyla during SESAME

The physical condition of polar stratospheric aerosols is of great importance both for the modelling of surface chemistry reactions and for the understanding of particle production and evaporation in the polar vortex. The particles can be either liquid, supercooled liquids or solid material at different heights and temperatures. Since a solid particle can survive much longer when temperature rises above the freezing point, whereas liquid particles will evaporate quickly at temperatures above the condensation temperature, the knowledge of the physical state is an important parameter to estimate the contribution to heterogenous chemistry of the different aerosol types observed.SubmittedSchliersee, Germany1.8. Osservazioni di geofisica ambientaleope

Lidar observations of liquid and solid PSC at Sodankyla

Polar stratospheric clouds (PSC) play a major role in the process of Artic and Antartic ozone depletion due to the surface provided for heterogeneus chemical reactions and the removal of NO2 from the gas phase. Therefore the phase, size and composition of PSC's should be known. The microphysical structure of the PSC's depends on the actual temperature and the corresponding; airmass thermal history. At temperatures below the ice frostpoint, PSC's of ice particles (Type II) are observed, while PSC's seen at temperatures above the frostpoint are classified as PSC Type Ia (anisotropic particles) and PSC Ib (spherical particles). PSC I were believed to consist of nitric acid trihydrate (NA'r). NAT should be stable some degrees above the ice frostpoint with a particle shape depending on the cooling rate [Toon et al., 1990]. However, the explanation of PSC based solely on the NAT-hypothesis can not explain a large amount of data [Toon and Tolbert, 1995]. The spherical shape of PSC Ib can be explained with a liquid supercooled ternary solution (STS) consisting of H2O, HNO3 and H2SO4. Scenarios for the formation of frozen background aerosol (sulfuric acid tetrahydrate, SAT) are now investigated. The described variance in shape and size of the PSC can be sensed by multispectral 2-polarization lidar, measuring range resolved scattering properties of atmospheric aerosols. Here the lidar observations of PSC's during the SESAME campaign are compared to the critical formation temperatures of the different PSC types.PublishedSchliersee, Germany1.8. Osservazioni di geofisica ambientaleope