Vitamin A metabolism in cultured somatic cells from rat testis

Sertoli and peritubular myoid cells, the somatic cells of the seminiferous tubule, support growth and differentiation of developing germ cells. This action strictly depends on the availability of in situ synthesized retinoic acid and we have previously documented the ability of Sertoli, but not peritubular cell extracts, to support the oxidation of retinol to retinoic acid. Using primary cultures of somatic cells treated with a physiological concentration of free retinol, we show here that the same is essentially true also for whole cultured cells. Sertoli cells are capable of producing not only retinoic acid, but are also the major site of retinyl ester (mainly, retinyl palmitate) formation. Compared with retinyl palmitate accumulation, retinoic acid synthesis was both faster and positively influenced by prior exposure to retinol. This increase in retinoic acid synthesis was further augmented by treatment with the retinoic acid catabolic inhibitor liarozole, thus indicating that enhanced synthesis, rather than reduced catabolism, is responsible for such an effect. Myoid cells had a higher capacity to incorporate exogenously supplied retinol, yet retinoic acid synthesis, and even more so retinyl palmitate formation, were considerably lower than in Sertoli cells. Retinoic acid synthesis in myoid cells was not only depressed, but also very little influenced by prior retinol exposure and totally insensitive to liarozole. These data further support the view that myoid cells are involved in retinol uptake from the blood and its transfer to other cells, rather than in metabolic interconversion or long-term storage of vitamin A, two processes that mainly take place in Sertoli cells

Numerical Simulation of the Performance of a Twin Scroll Radial Turbine at Different Operating Conditions

Twin scroll radial turbines are increasingly used for turbocharging applications, to take advantage of the pulsating exhaust gases. In spite of its relevance in turbocharging techniques, scientific literature about CFD applied to twin scroll turbines is limited, especially in case of partial admission. In the present paper a CFD complete model of a twin scroll radial turbine is developed in order to give a contribution to literature in understanding the capabilities of current industrial CFD approaches applied to these difficult cases and to develop performance index that can be used for turbine design optimization purposes. The flow solution is obtained by means of ANSYS CFX \uae in a wide range of operating conditions in full and partial admission cases. The total-to-static efficiency and the mass flow parameter (MFP) have been calculated and compared with the experimental database in order to validate the numerical model. The purpose of the developed procedure is also to generate a database for twin scroll turbines useful for future applications. A comparison between performances obtained in different admission conditions was performed. In particular the analysis focused on the characterization of the flow at volute outlet/rotor inlet section. A flow distortion index at rotor inlet was introduced to correlate the turbine performance and the flow nonuniformities generated by the volute. Finally the influence of the backside cavity on the performance parameters is also discussed. The introduction of these new nonuniformity indices is proposed for volute design and optimization procedures

Comparing activity and space patterns of the European pond turtle, Emys orbicularis (L., 1758) in a Venice Lagoon wetland area: implications for conservation planning and management

Behavioural and spatial distribution analyses were quantified during a phase of activity and lethargy in a wild population of the European pond turtle inhabiting a protected internal wetland area of the Venice lagoon. The marked individuals (13 males and 16 females) provided informative radiotracking data to study differential patterns of activity, dispersion and habitat use between the two study periods ("October-November both 2019 and 2020" and "June-July 2020"). The differences in the movements behaviours and habitat selection were affected by period. Movements were higher in the period of activity than lethargy, but they were not influenced by sex and size. The presence of the European pond turtle in the transitional woodland/shrubs and brackish water valley habitats was significantly higher in the period of activity than lethargy. During the latter one, pond turtles were observed to brumate gregariously in a small area for brumation, usually in shallow water. In contrast, all individuals have changed water bodies during the activity period. Part of those movements has occurred towards aquatic habitat with higher salinities 1-17%o (mean: 10.64%o). These findings provide a set of information to better understand the behavioural ecology of Emys orbicularis in the lagoon area. This is of relevance for management actions and for the conservation of this threatened species

Distribution and biology of the Blackmouth catshark Galeus melastomus in the Strait of Sicily (Central Mediterranean Sea)

The Blackmouth catshark, Galeus melastomus, Rafinesque, 1810 (Carcharhiniformes; Scyliorhinidae), is a common, although at present discarded, by- catch of the bottom trawl fisheries in the Strait of Sicily. Given its ecological interest, data gathered in experimental bottom trawl surveys were analysed in order to describe its distribution and main biological traits. The Blackmouth catshark was sampled almost exclusively on the upper slope (200-800), showing the highest frequency of occurrence (69-100%), biomass (BI; 10-85 kg*km-2) and density (DI; 54-506 N*km-2) indexes in the deeper (501-800m) grounds. Individual size (total length, TL, mm) were between 70-590 and 90-510 in females and males, respectively. The sex ratio (SR) was around 0.5. The SR by size showed a gradual decrease till 450 mm class size, followed by an increase up 1 after 500 mm. Virginal/immature specimens represented the bulk of the samples in both females (77%) and males (65%); the length at 50% of sexual maturity (Lm50%) and corresponding maturity range (Lm25% - Lm75% ) was 433 (423-443) and 380 (366-394) mm, respectively

So close so different: what makes the difference?

The introduction of alien fish species in wetland ecosystems could have a great impact on freshwater communities and ecological processes. Despite fish introduction has been noticed as one of the principal cause of freshwater extinctions, ecosystem processes alteration, and change in aquatic community assemblage, very few data about impact on freshwater reptiles are available. As study model we used two neighbour sub-populations of the endangered Sicilian pond turtle, Emys trinacris, inhabiting two small, close each other and very similar lakes, except for the presence of allocthonous fish, Cyprinus carpio and Gambusia hoolbroki in one of the two. The multi-year study allowed highlighting significant differences in abundance, growth and reproductive output between the two freshwater turtle sub-populations, suggesting their influence on phenotypic plasticity of the studied population. These results are discussed in the light of previous evidence about the impact of these alien species on abundance and assemblage of the invertebrate community with an evident impact on niche width, diet composition and therefore energy intake by Emys trinacris. These data may provide important information to address management strategies and conservation actions of small wetland areas inhabited by pond turtles, pointing out a threats never highlighted up to now

Structural stability of Fe5Si3 and Ni2Si studied by high-pressure x-ray diffraction and ab initio total-energy calculations

We performed high-pressure angle dispersive x-ray diffraction measurements on Fe5Si3 and Ni2Si up to 75 GPa. Both materials were synthesized in bulk quantities via a solid-state reaction. In the pressure range covered by the experiments, no evidence of the occurrence of phase transitions was observed. On top of that, Fe5Si3 was found to compress isotropically, whereas an anisotropic compression was observed in Ni2Si. The linear incompressibility of Ni2Si along the c-axis is similar in magnitude to the linear incompressibility of diamond. This fact is related to the higher valence-electron charge density of Ni2Si along the c-axis. The observed anisotropic compression of Ni2Si is also related to the layered structure of Ni2Si where hexagonal layers of Ni2+ cations alternate with graphite-like layers formed by (NiSi)2- entities. The experimental results are supported by ab initio total-energy calculations carried out using density functional theory and the pseudopotential method. For Fe5Si3, the calculations also predicted a phase transition at 283 GPa from the hexagonal P63/mcm phase to the cubic structure adopted by Fe and Si in the garnet Fe5Si3O12. The room-temperature equations of state for Fe5Si3 and Ni2Si are also reported and a possible correlation between the bulk modulus of iron silicides and the coordination number of their minority element is discussed. Finally, we report novel descriptions of these structures, in particular of the predicted high-pressure phase of Fe5Si3 (the cation subarray in the garnet Fe5Si3O12), which can be derived from spinel Fe2SiO4 (Fe6Si3O12).Comment: 44 pages, 13 figures, 3 Table

A respirable HPV-L2 dry-powder vaccine with GLA as amphiphilic lubricant and immune-adjuvant

Vaccines not requiring cold-chain storage/distribution and suitable for needle-free delivery are urgently needed. Pulmonary administration is one of the most promising non-parenteral routes for vaccine delivery. Through a multi-component excipient and spray-drying approach, we engineered highly respirable dry-powder vaccine particles containing a three-fold repeated peptide epitope derived from human papillomavirus (HPV16) minor capsid protein L2 displayed on Pyrococcus furious thioredoxin as antigen. A key feature of our engineering approach was the use of the amphiphilic endotoxin derivative glucopyranosyl lipid A (GLA) as both a coating agent enhancing particle de-aggregation and respirability as well as a built-in immune-adjuvant. Following an extensive characterization of the in vitro aerodynamic performance, lung deposition was verified in vivo by intratracheal administration in mice of a vaccine powder containing a fluorescently labeled derivative of the antigen. This was followed by a short-term immunization study that highlighted the ability of the GLA-adjuvanted vaccine powder to induce an anti-L2 systemic immune response comparable to (or even better than) that of the subcutaneously administered liquid-form vaccine. Despite the very short-term immunization conditions employed for this preliminary vaccination experiment, the intratracheally administered dry-powder, but not the subcutaneously injected liquid-state, vaccine induced consistent HPV neutralizing responses. Overall, the present data provide proof-of-concept validation of a new formulation design to produce a dry-powder vaccine that may be easily transferred to other antigens

Urinary metabolomics (GC-MS) reveals that low and high birth weight infants share elevated inositol concentrations at birth

Objective: Metabolomics is a new ‘‘omics’’ platform aimed at high-throughput identification, quantification and characterization of small molecule metabolites. The metabolomics approach has been successfully applied to the classification different physiological states and identification of perturbed biochemical pathways. The purpose of the current investigation is the application of metabolomics to explore biological mechanisms which may lead to the onset of metabolic syndrome in adulthood. Methods: We evaluated differences in metabolites in the urine collected within 12 hours from 23 infants with IUGR (IntraUterine Growth Restriction), or LGA (Large for Gestational Age), compared to control infants (10 patients defined AGA: Appropriate for Gestational Age). Urinary metabolites were quantified by GC-MS and used to highlight similarities between the two metabolic diseases and identify metabolic markers for their predisposition. Quantified metabolites were analyzed using a multivariate statistics coupled with receiver operator characteristic curve (ROC) analysis of identified biomarkers. Results: Urinary myo-inositol was the most important discriminant between LGA + IUGR and control infants, and displayed an area under the ROC curve¼1. Conclusion: We postulate that the increase in plasma and consequently urinary inositol may constitute a marker of altered glucose metabolism during fetal development in both IUGR and LGA newborns

Between GERD and NERD: the relevance of weakly acidic reflux

Nonerosive reflux disease (NERD) is a common condition and the most frequent phenotype of gastroesophageal reflux disease (GERD). NERD is extremely heterogeneous and includes patients with negative endoscopy but abnormal esophageal acid exposure and/or positive reflux-symptom association analysis (hypersensitive esophagus). This segregation is only possible owing to the use of impedance-pH monitoring. Indeed, weakly acidic reflux represents one of the most common causes of refractory symptoms in patients evaluated off antisecretory therapy and, more importantly, during antisecretory drug treatment. Patients with heartburn who do not have any type of reflux underlying their symptoms (functional heartburn) must be excluded from the category of GERD. The drawbacks of impedance-pH are mainly due to the day-to-day variability of the test and the fact that the accuracy of the symptom-reflux correlation scores is often far from perfect. Some histopathological characteristics, such as dilated intercellular spaces, can be helpful in distinguishing patients with NERD through esophageal biopsies. Patients with NERD in whom acid is the main pathogenetic factor respond successfully to proton pump inhibitor therapy, while those with hypersensitive esophagus to weakly acidic reflux could be treated with reflux inhibitors or surgery, although further controlled studies are required

A new multianodic large area photomultiplier to be used in underwater neutrino detectors

In this article we describe the properties of a new 10-in. hemispherical photomultiplier manufactured by Hamamatsu. The prototype has a segmented photocathode and four independent amplification stages. The photomultiplier is one of the main components of a newly designed direction-sensitive optical module to be employed in large-scale underwater neutrino telescopes. The R&D activity has been co-funded by the INFN and the KM3NeT Consortium. The prototype performance fully meets with the design specifications