Compared patterns of arm regeneration in different taxa of armed echinoderms

Regeneration is a post-embryonic developmental process common in Metazoa, although it tends to be less widespread in the more complex-bodied phyla. An exception to this rule are echinoderms, which are known for phylum-wide and extremely advanced regenerative abilities, being able to regrow all appendages, and often large parts of the central body and viscera (CANDIA CARNEVALI, 2006). Armed echinoderms (Crinoidea, Asteroidea, and Ophiuroidea) are especially practical models as their arms are easy to amputate, and their proximo-distal extension provides a useful reference point to describe the regenerative processes. Samples of four species from these taxa \u2013 the crinoid Antedon mediterranea, the asteroids Echinaster sepositus and Coscinasterias tenuispina, and the ophiuroid Amphipholis squamata \u2013 were subjected to arm amputation to study the progression of arm regeneration from a morphological point of view by means of different microscopy analyses. Particular attention was given to the \u201caxial structures\u201d, defined as the continuous elements running along the proximo-distal axis of each arm, namely the radial water canal, the radial nerve cord, and the arm coelom, as they are believed to be fundamental for the re-organization of the regenerating arm. The comparison highlighted commonalities and differences of arm regeneration in the different taxa. Distal structures, represented in crinoids by the apical blastema and in asteroids and ophiuroids by the terminal ossicle and tube foot, form very quickly, whereas the proximal region develops later, in proximal-to-distal direction. This is in accordance with previously published models of echinoderm regeneration (MOOI et al., 2005; BEN KHADRA et al., 2018). These similarities suggest that the mechanism of regeneration has ancient origins and is extremely conserved through echinoderm evolution. Within the proximal region, the axial structures themselves develop earlier than the nearby discrete structures (e.g. ossicles and tube feet), and seem to have a crucial role in their organization, providing material and possible signalling molecules for the growing tissue. The cellular component of the nerve grows before any other structure, including its own fibres, thus confirming a primary role of the nervous system in the whole process. Molecular analyses must be combined to morphology data to improve our understanding of similarities and differences of the regenerative process as it occurs in the different echinoderm taxa, as well as in different animal phyla, and to identify related processes in both regeneration-competent and non-competent species. References Ben Khadra Y, Sugni M, Ferrario C, Bonasoro F, Oliveri P, Martinez P, Candia Carnevali MD. 2018. Regeneration in Stellate Echinoderms: Crinoidea, Asteroidea and Ophiuroidea. M. Kloc, J. Z. Kubiak (eds.) Marine Organisms as Model Systems in Biology and Medicine. \ua9Springer International Publishing AG, part of Springer Nature 2018. Chapter 14 Candia Carnevali MD. 2006. Regeneration in Echinoderms: repair, regrowth, cloning. Invertebrate Survival Journal, 3 (1): 64-76 Mooi R, David B, Wray GA. 2005. Arrays in rays: terminal addition in echinoderms and its correlation with gene expression. Evolution & Development, 7 (6): 542-55

Acetic acid stress response of the acidophilic sulfate reducer Acididesulfobacillus acetoxydans

Acid mine drainage (AMD) waters are a severe environmental threat, due to their high metal content and low pH (pH <3). Current technologies treating AMD utilize neutrophilic sulfate-reducing microorganisms (SRMs), but acidophilic SRM could offer advantages. As AMDs are low in organics these processes require electron donor addition, which is often incompletely oxidized into organic acids (e.g., acetic acid). At low pH, acetic acid is undissociated and toxic to microorganisms. We investigated the stress response of the acetotrophic Acididesulfobacillus acetoxydans to acetic acid. A. acetoxydans was cultivated in bioreactors at pH 5.0 (optimum). For stress experiments, triplicate reactors were spiked until 7.5 mM of acetic acid and compared with (non-spiked) triplicate reactors for physiological, transcriptomic, and membrane lipid changes. After acetic acid spiking, the optical density initially dropped, followed by an adaptation phase during which growth resumed at a lower growth rate. Transcriptome analysis revealed a downregulation of genes involved in glutamate and aspartate synthesis following spiking. Membrane lipid analysis revealed a decrease in iso and anteiso fatty acid relative abundance; and an increase of acetyl-CoA as a fatty acid precursor. These adaptations allow A. acetoxydans to detoxify acetic acid, creating milder conditions for other microorganisms in AMD environments

IL28B gene polymorphism rs12979860, but not rs8099917, contributes to the occurrence of chronic HCV infection in uruguayan patients

Background: Host single-nucleotide polymorphisms (SNPs) near the interleukin 28B (IL28B) locus are associated with sustained virological response to antiviral therapy and with spontaneous Hepatitis C Virus (HCV) clearance. Prevalence of these SNPs varies depending on ethnicity. The impact of IL28B SNPs in HCV-infected patients is currently unknown in Uruguay. Therefore, the aim of this study was to evaluate and compare the distribution of polymorphisms in the IL28B gene (rs12979860 and rs8099917) among HCV-infected patients and healthy individuals in Uruguay and thus assess their possible association with the establishment of HCV infection. Methods: DNA was recovered from 92 non-infected individuals and 78 HCV-infected patients and SNPs were determined by RFLP and allelic discrimination by real-time PCR. Results: The distribution of rs12979860 genotypes for the infected population was 29.5%-CC, 47.4%-CT and 23.1%-TT and for the control group 45.7,% 42.4% and 11.9,% respectively. Prevalence in both infected and uninfected individuals is similar to that reported in other countries with admixed populations. The distribution of rs8099917 genotypes for the infected population was 57.7%-TT, 27.2%-TG and 14.1%-GG and for the control group 60.9,% 33.7% and 5.4,% respectively. The comparison of rs12979860 genotype distribution between the two populations evidenced a higher prevalence of the favourable genotype (CC) in the uninfected control group (p < 0.05). Additionally, results generated using logistic regression analysis show that individuals carrying rs12979860-TT or CT genotypes have a higher likelihood of developing chronic hepatitis upon infection with HCV, when compared to CC carriers, considering rs8099917 genotype as constant. Conclusion: Patients with HCV infection have a statistically significant lower prevalence of the favourable rs12979860 genotype when compared to uninfected individuals; therefore we can establish that only IL28B rs12979860-CT and TT genotypes seem to contribute to the occurrence of chronic HCV infection in the cohort of Uruguayan population studied. Considering that a trend towards a higher frequency of "good" response genotypes was observed in responder patients, we believe that IL28B rs12979860 genotyping could be a useful tool for predicting different therapies outcome, including in the DAA era

Mono- to tetra-alkyl ether cardiolipins in a mesophilic, sulfate-reducing bacterium identified by UHPLC-HRMSn: a novel class of membrane lipids

The composition of membrane lipids varies in a number of ways as adjustment to growth conditions. Variations in head group composition and carbon skeleton and degree of unsaturation of glycerol-bound acyl or alkyl chains results in a high structural complexity of the lipidome of bacterial cells. We studied the lipidome of the mesophilic, sulfate-reducing bacterium, Desulfatibacillum alkenivorans strain PF2803T by ultra-high-pressure liquid chromatography coupled with high-resolution tandem mass spectrometry (UHPLC-HRMSn). This anaerobic bacterium has been previously shown to produce high amounts of mono-and di-alkyl glycerol ethers as core membrane lipids. Our analyses revealed that these core lipids occur with phosphatidylethanomamine (PE) and phosphatidylglycerol (PG) head groups, representing each approximately one third of the phospholipids. The third class was a novel group of phospholipids, i.e., cardiolipins (CDLs) containing one (monoether/triester) to four (tetraether) ether-linked saturated straight-chain or methyl-branched alkyl chains. Tetraether CDLs have been shown to occur in archaea (with isoprenoid alkyl chains) but have not been previously reported in the bacterial Domain. Structurally related CDLs with one or two alkyl/acyl chains missing, so-called monolyso-and dilyso-CDLs, were also observed. The potential biosynthetic pathway of these novel CDLs was investigated by examining the genome of D. alkenivorans. Three CDL synthases were identified; one catalyzes the condensation of two PGs, the other two are probably involved in the condensation of a PE with a PG. A heterologous gene expression experiment showed the in vivo production of dialkylglycerols upon anaerobic expression of the glycerol ester reductase enzyme of D. alkenivorans in E. coli. Reduction of the ester bonds probably occurs first at the sn-1 and subsequently at the sn-2 position after the formation of PEs and PGs

Travelling-wave resonant four-wave mixing breaks the limits of cavity-enhanced all-optical wavelength conversion

Wave mixing inside optical resonators, while experiencing a large enhancement of the nonlinear interaction efficiency, suffers from strong bandwidth constraints, preventing its practical exploitation for processing broad-band signals. Here we show that such limits are overcome by the new concept of travelling-wave resonant four-wave mixing (FWM). This approach combines the efficiency enhancement provided by resonant propagation with a wide-band conversion process. Compared with conventional FWM in bare waveguides, it exhibits higher robustness against chromatic dispersion and propagation loss, while preserving transparency to modulation formats. Travelling-wave resonant FWM has been demonstrated in silicon-coupled ring resonators and was exploited to realize a 630-μm-long wavelength converter operating over a wavelength range wider than 60 nm and with 28-dB gain with respect to a bare waveguide of the same physical length. Full compatibility of the travelling-wave resonant FWM with optical signal processing applications has been demonstrated through signal retiming and reshaping at 10 Gb s−

Pharmacogenetic Associations of MMP9 and MMP12 Variants with Cardiovascular Disease in Patients with Hypertension

MMP-9 and -12 function in tissue remodeling and may play roles in cardiovascular disease (CVD). We assessed associations of four MMP polymorphisms and three antihypertensive drugs with cardiovascular outcomes.Hypertensives (n = 42,418) from a double-blind, randomized, clinical trial were randomized to chlorthalidone, amlodipine, lisinopril, or doxazosin treatment (mean follow up, 4.9 years). The primary outcome was coronary heart disease (CHD). Secondary outcomes included combined CHD, all CVD outcomes combined, stroke, heart failure (HF), and mortality. Genotype-treatment interactions were tested. = 0.015). for CHD and composite CVD. The data suggest that these genes may provide useful clinical information with respect to treatment decisions

Causas antrópicas.

Alguns dos principais fatores antrópicos identificados que desencadearam a devastação das florestas nativas foram a caça, exploração agropecuária, queimadas, extração vegetal, lazer, urbanização e a implantação de infraestrutura de transportes, energia e saneamento. em quase todos eles foram identificados vínculos com atividades e políticas econômicas ou então, se constituem como estratégias de sobrevivência frente às adversidades destas. Esses levantamentos permitiram perceber que os diferentes estágios de fragmentação são decorrentes dos diferentes padrões de desenvolvimento social e econômico, nacional, regional e locais

PHASE-SENSITIVE LOW-COHERENCE INTERFEROMETRY APPARATUS

The invention relates to an interferometry apparatus (100) for measuring at least one parameter of a sample (S) comprising: first (S1) and second (S2) sources, respectively, of first (So1) and second (So2) electromagnetic radiations, having distinct wavelengths and time coherences; interference means (50) of said radiations to provide a combination electromagnetic signal (Soc2) of first (Soi1) and second (Soi2) interference electromagnetic signals between portions, of first and second radiations, respectively. The apparatus being characterized in that it further comprises: a device (PD) for converting the combination electromagnetic signal (Soc2) into a corresponding combined electric signal (Sce) and separation electronic means (F-B) of the combined electric signal (Sce) into first (Se1) and second (Se2) electric signals representative of said interference signals (Soi1, Soi2), respectively

Apparato di interferometria a bassa coerenza sensibile alla fase

The invention relates to an interferometry apparatus (100) for measuring at least one parameter of a sample (S) comprising: first (S1) and second (S2) sources, respectively, of first (So1) and second (So2) electromagnetic radiations, having distinct wavelengths and time coherences; interference means (50) of said radiations to provide a combination electromagnetic signal (Soc2) of first (Soi1) and second (Soi2) interference electromagnetic signals between portions, of first and second radiations, respectively. The apparatus being characterized in that it further comprises: a device (PD) for converting the combination electromagnetic signal (Soc2) into a corresponding combined electric signal (Sce) and separation electronic means (F-B) of the combined electric signal (SSoi2), respectively