Yellow tails in the Red Sea: phylogeography of the Indo-Pacific goatfish Mulloidichthys flavolineatus reveals isolation in peripheral provinces and cryptic evolutionary lineages

Aim: Broadly distributed reef fishes tend to have high gene flow mediated by a pelagic larval phase. Here, we survey a reef-associated fish distributed across half the tropical oceans, from the Red Sea to the central Pacific. Our goal is to determine whether genetic structure of the broadly distributed Yellowstripe Goatfish (Mulloidichthys flavolineatus) is defined by biogeographical barriers, or facilitated via larval dispersal. Location: Red Sea, Indian Ocean, Pacific Ocean. Methods: Specimens were obtained at 19 locations from the Red Sea to Hawai'i. Genetic data include mtDNA cytochrome b (n = 217) and 12 microsatellite loci (n = 185). Analysis of molecular variance (AMOVA), structure, a parsimony network and coalescence analyses were used to resolve recent population history and connectivity. Results: Population structure was significant (mtDNA ϕST = 0.68, P < 0.001; microsatellite FST = 0.08, P < 0.001), but mostly driven by samples from the North-western (NW) Indian Ocean (including the Red Sea) and Hawai'i. There was little population structure across the Indian Ocean to the central Pacific. Hawai'i was distinguished as an isolated population (mtDNA ϕST = 0.03–0.08, P = n.s.; microsatellites FST = 0.05–0.10, P < 0.001). Specimens from the NW Indian Ocean clustered as a distinct phylogenetic lineage that diverged approximately 493 ka (d = 1.7%), which indicates that these fish persisted in isolation through several Pleistocene glacial cycles. Main conclusions: These data reinforce the emerging themes that: (1) phylogeographical breaks within species often coincide with biogeographical breaks based on species distributions, and (2) populations on the periphery of the range (NW Indian Ocean and Hawai'i) are isolated and may be evolutionary incubators producing new species

Clinical oxidative stress during leprosy multidrug therapy:impact of dapsone oxidation

This study aims to assess the oxidative stress in leprosy patients under multidrug therapy (MDT; dapsone, clofazimine and rifampicin), evaluating the nitric oxide (NO) concentration, catalase (CAT) and superoxide dismutase (SOD) activities, glutathione (GSH) levels, total antioxidant capacity, lipid peroxidation, and methemoglobin formation. For this, we analyzed 23 leprosy patients and 20 healthy individuals from the Amazon region, Brazil, aged between 20 and 45 years. Blood sampling enabled the evaluation of leprosy patients prior to starting multidrug therapy (called MDT 0) and until the third month of multidrug therapy (MDT 3). With regard to dapsone (DDS) plasma levels, we showed that there was no statistical difference in drug plasma levels between multibacillary (0.518±0.029 μg/mL) and paucibacillary (0.662±0.123 μg/mL) patients. The methemoglobin levels and numbers of Heinz bodies were significantly enhanced after the third MDTsupervised dose, but this treatment did not significantly change the lipid peroxidation and NO levels in these leprosy patients. In addition, CAT activity was significantly reduced in MDT-treated leprosy patients, while GSH content was increased in these patients. However, SOD and Trolox equivalent antioxidant capacity levels were similar in patients with and without treatment. These data suggest that MDT can reduce the activity of some antioxidant enzyme and influence ROS accumulation, which may induce hematological changes, such as methemoglobinemia in patients with leprosy. We also explored some redox mechanisms associated with DDS and its main oxidative metabolite DDS-NHOH and we explored the possible binding of DDS to the active site of CYP2C19 with the aid of molecular modeling software

Measuring and Comparing Party Ideology and Heterogeneity

Estimates of party ideological positions in Western Democracies yield useful party-level information, but lack the ability to provide insight into intraparty politics. In this paper, we generate comparable measures of latent individual policy positions from elite survey data which enable analysis of elite-level party ideology and heterogeneity. This approach has advantages over both expert surveys and approaches based on behavioral data, such as roll call voting and is directly relevant to the study of party cohesion. We generate a measure of elite positions for several European countries using a common space scaling approach and demonstrate its validity as a measure of party ideology. We then apply these data to determine the sources of party heterogeneity, focusing on the role of intraparty competition in electoral systems, nomination rules, and party goals. We find that policy-seeking parties and centralized party nomination rules reduce party heterogeneity. While intraparty competition has no effect, the presence of these electoral rules conditions the effect of district magnitude

Experimental and numerical evaluation of viscoelastic sandwich beams

Abstract Viscoelastic materials can dissipate a large amount of energy when subjected to cyclic shear deformations, but they have low bearing capacity. Therefore they are often employed as a damping layer in sandwich structures. These sandwich structures present a high damping ratio and simple application. In order to design sandwich structures, many aspects ranging from computer modeling to laboratory testing should be considered. In this study, a test set of experiments were performed and results are compared with a numerical GHM (Golla, Hughes and Mc Tavish method) based model, in order to establish a method to support viscoelastic sandwich beam design. In this way, starting from the dynamic properties of a viscoelastic material, a numerical model is used to evaluate the behavior of these structures. Comparisons with uncontrolled structures are also presented, showing the dissipative characteristics of this passive control.</div

Supporting alternative strategies for learning chemical applications of group theory

A group theory course for chemists was taught entirely with process oriented guided inquiry learning (POGIL) to facilitate alternative strategies for learning. Students completed a test of one aspect of visuospatial aptitude to determine their individual approaches to solving spatial tasks, and were sorted into groups for analysis on the basis of their aptitude. Affective constructs from self-determination theory relating to motivation were also assessed. Students without strong visuospatial skills found the activities more interesting and enjoyable than students who could successfully complete spatial tasks. Equally successful outcomes were observed on an assessment task, irrespective of visuospatial aptitude of the student. This illustrates that a pedagogy structured around multiple strategies for reasoning can successfully support alternative approaches to abstract concepts, such as chemical applications of group theory

Release and persistence of extracellular DNA in the environment

The introduction of genetically modified organisms (GMOs) has called for an improved understanding of the fate of DNA in various environments, because extracellular DNA may also be important for transferring genetic information between individuals and species. Accumulating nucleotide sequence data suggest that acquisition of foreign DNA by horizontal gene transfer (HGT) is of considerable importance in bacterial evolution. The uptake of extracellular DNA by natural transformation is one of several ways bacteria can acquire new genetic information given sufficient size, concentration and integrity of the DNA. We review studies on the release, breakdown and persistence of bacterial and plant DNA in soil, sediment and water, with a focus on the accessibility of the extracellular nucleic acids as substrate for competent bacteria. DNA fragments often persist over time in many environments, thereby facilitating their detection and characterization. Nevertheless, the long-term physical persistence of DNA fragments of limited size observed by PCR and Southern hybridization often contrasts with the short-term availability of extracellular DNA to competent bacteria studied in microcosms. The main factors leading to breakdown of extracellular DNA are presented. There is a need for improved methods for accurately determining the degradation routes and the persistence, integrity and potential for horizontal transfer of DNA released from various organisms throughout their lifecycles