Structural Parameters Of Lamellar Phases Formed By The Self-assembly Of Dialkyldimethylammonium Bromides In Aqueous Solution

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Phase behavior of didodecyl and dioctadecydimethylammonium bromide (DDAB and DODAB) in water was studied using X-ray techniques, differential scanning calorimetry and deuterium nuclear magnetic resonance measurements. Both surfactants self-assemble into lamellar liquid crystalline, either L-alpha (fluid) and L-beta (gel), phases. The gel-to-fluid phase transition temperature (T-m) in DDAB lamellae was found to be higher than that observed for its vesicles, due to the formation of a stabilized gel phase. In addition, the lamellar phases formed by both amphiphiles differ in their swelling degree and bilayer thickness. DODAB in water formed rather thin bilayers, if compared with the length of the tails, suggesting effective chain interdigitation. These bilayers also presented higher swelling degree than those formed by the shorter-chain homologue DDAB. We propose that these structural properties are strongly influenced by the electrostatic repulsive forces acting on the system.272392401CNPqConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Structural parameters of lamellar phases formed by the self-assembly of dialkyldimethylammonium bromides in aqueous solution

Phase behavior of didodecyl and dioctadecydimethylammonium bromide (DDAB and DODAB) in water was studied using X-ray techniques, differential scanning calorimetry and deuterium nuclear magnetic resonance measurements. Both surfactants self-assemble into lamellar liquid crystalline, either Lα (fluid) and Lβ (gel), phases. The gel-to-fluid phase transition temperature (Tm) in DDAB lamellae was found to be higher than that observed for its vesicles, due to the formation of a stabilized gel phase. In addition, the lamellar phases formed by both amphiphiles differ in their swelling degree and bilayer thickness. DODAB in water formed rather thin bilayers, if compared with the length of the tails, suggesting effective chain interdigitation. These bilayers also presented higher swelling degree than those formed by the shorter-chain homologue DDAB. We propose that these structural properties are strongly influenced by the electrostatic repulsive forces acting on the system272392401CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQSem informaçã

On the improvement of localization accuracy with nonindividualized HRTF-based sounds

Auralization is a powerful tool to increase the realism and sense of immersion in Virtual Reality environments. The Head Related Transfer Function (HRTF) filters commonly used for auralization are non-individualized, as obtaining individualized HRTFs poses very serious practical difficulties. It is therefore extremely important to understand to what extent this hinders sound perception. In this paper, we address this issue from a learning perspective. In a set of experiments, we observed that mere exposure to virtual sounds processed with generic HRTF did not improve the subjects’ performance in sound source localization, but short training periods involving active learning and feedback led to significantly better results. We propose that using auralization with non-individualized HRTF should always be preceded by a learning period.Fundação para a Ciência e a Tecnologia (FCT)FEDE

Comparação de dois algoritmos genéticos aplicados ao TOP

A recolha seletiva de resíduos sólidos urbanos para reciclagem é um processo dispendioso, especialmente quando realizado em grande escala. Um problema importante neste processo reside na gestão de uma frota, uma vez que atualmente as estratégias utilizadas geralmente têm baixa eficiência. O processo de recolha seletiva de resíduos sólidos urbanos pode ser modelado como um problema de encaminhamento de veículos, em particular como um Problema de Orientação de Equipas (TOP - Team Orienteering Problem). No TOP uma frota de veículos é incumbida de visitar um conjunto selecionado de vértices, de modo a maximizar o luvro total. O objetivo deste trabalho é o de otimizar o processo de recolha selectiva de resíduos sólidos urbanos ao abordar as questões relacionadas com a gestão de uma frota. Isso deve ser alcançado através do desenvolvimento de uma ferramenta de software que implementa um algoritmo genético para resolver o modelo desenvolvido. Neste artigo apresentamos e comparamos dois algoritmos genéticos através de experiências computacionais realizadas com instâncias de teste conhecidas da literatura. O uso de algoritmos genéticos para resolver o TOP mostra ser uma escolha acertada, pois o método é eficiente produzindo bons resultados num tempo aceitável.Fundos FEDER através do Programa Operacional Fatores de Competitividade – COMPETE e por Fundos Nacionais através da FCT – Fundação para a Ciência e Tecnologia no âmbito do Projeto: FCOMP-01-0124-FEDER-022674GATOP - Genetic Algorithms for Team Orienteering Problem (Ref PTDC/EME-GIN/ 120761/2010), financiado por fundos nacionais pela FCT / MCTES e co-financiado pelo by the European Social Development Fund (FEDER) through the COMPETE Programa Operacional Fatores de Competitividade (POFC) Ref FCOMP-01-0124-FEDER-020609

Liquid chromatography-mass spectrometry for simultaneous determination of spironolactone and canrenone in plasma samples

In our study, we aimed to validate a method based on liquid chromatography-mass spectrometry (LC-MS) to quantify spironolactone (SPI) and its active metabolite canrenone (CAN) simultaneously in plasma samples to support in vivo experiments. Compounds were separated by using a C18 column with the isocratic elution of a mobile phase composed of 0.1% (v/v) formic acid in methanol-water (60:40 v/v) at a flow rate of 0.4 mL min−1. SPI and CAN were detected in na electrospray interface operating in a positive ionization mode and quantified using the selective ion mode monitoring of mass-charge ratios (m/z) of 439.0 for SPI and 363.1 for CAN. After calculating the matrix effect using theoretical equations, we observed the strong interference of plasma in the equipment-generated signal, which required creating analytical curves using the matrix as a solvent. The method was nevertheless linear (r 2 > 0.999) in a concentration range of 0.4-5.0 μg mL−1, as well as precise, with a coefficient of variation less than 5%. SPI’s and CAN’s recovery rates from the plasma ranged from 87.4% to 112.1%, while their limits of detection (i.e., 0.07 μg mL−1 and 0.03 μg mL−1, respectively) and quantification (i.e., 0.20 μg mL−1 and 0.08 μg mL−1, respectively) in the presence of plasma contaminants were low. Therefore, the bioanalytical method seems to be feasible for quantifying SPI and CAN in plasma

Nutrição de tithonia diversifolia e atributos do solo adubado com biofertilizante em sistema irrigado

The fertilization with biofertilizer associated with the use of irrigation favors nutrient uptake by plants and soil chemical properties; however, these effects are little studied in Tithonia diversifolia in semiarid regions. This study evaluated the effect of doses of bovine biofertilizer and irrigation on accumulation of nutrients in the leaves of Tithonia diversifolia plants and on soil chemical attributes. The study was carried out from December 3, 2014 to November 28, 2015, and arranged in a 2 x 5 factorial scheme, consisting of five doses of bovine biofertilizer (0, 40, 80, 120 and 160 m3 ha-1), combined with and without irrigation. The experiment was set in a randomized block design, using three replicates. Irrigation promoted increased accumulation of N, P, K, Ca, Mg, S, Zn, Fe, Mn, Cu and B in leaves of Tithonia diversifolia in the first cutting. However, the high bicarbonate concentration in the irrigation water and the occurrence of rainfall during the second crop increased the accumulation of Cu in the leaves of Tithonia diversifolia under rainfed condition, compared with irrigated plants. The increase in biofertilizer doses contributed to the increment of base saturation and the contents of organic matter, P and K in soil201110081013Associada ao uso de irrigação, a adubação com biofertilizante favorece a absorção de nutrientes pelas plantas e as propriedades químicas dos solos, porém tais efeitos são pouco estudados no cultivo de Tithonia diversifolia em regiões semiáridas. Avaliaram-se os efeitos de doses de biofertilizante bovino e da irrigação no acúmulo foliar de nutrientes em plantas de Tithonia diversifolia e nos atributos químicos do solo. O estudo foi conduzido entre 3 de dezembro de 2014 e 28 de novembro de 2015 e distribuído em esquema fatorial 5 x 2, consistindo de cinco doses de biofertilizante bovino (0, 40, 80, 120 e 160 m3 ha-1), combinado com e sem irrigação. O delineamento estatístico do experimento foi em blocos casualizados com três repetições. A irrigação promoveu aumento no acúmulo de N, P, K, Ca, Mg, S, Zn, Fe, Mn, Cu e B em folhas de Tithonia diversifolia no primeiro corte; entretanto, a alta concentração de bicarbonato na água de irrigação e a presença de chuvas durante o segundo cultivo aumentaram o acúmulo de Cu nas folhas de Tithonia diversifolia em sequeiro quando comparado às plantas irrigadas. O aumento das doses de biofertilizante contribuiu para o incremento da saturação por base e do teor de matéria orgânica, P e K no sol

Anxiety and depression symptoms after pulmonary rehabilitation in people with interstitial lung disease: responders and non-responders

Pulmonary rehabilitation (PR) is an effective intervention for people with interstitial lung disease (ILD), as it improvesexercise capacity, quality of life and dyspnoea. Less is, however, known about other important and frequentsymptoms, such as anxiety and depression. This study explored the response of anxiety and depression symptomsto PR in people with ILD. Participants undertook a 12-week community-based PR programme. Anxiety and depression symptoms wereevaluated before and after PR with the hospital anxiety and depression scale (HADS). The sample was stratified into2 groups according to the HADS score: ≥8 probable anxiety (PA) or depression (PD) and score <8 normal symptoms(NS). Responders were classified using the HADS minimal clinical important difference (≥1.5 points). 46 people with ILD (62±13 years; 63%♀; 75±20 FVC%; 56±18 DLCO%) participated. Number of responders inanxiety symptoms (73% PA; HADS-A pre: 12±3; mean change: 4±2; p<0.001 vs 25% NS; HADS-A pre: 6±2; meanchange: 2±0; p<0.001) was much higher than in depression symptoms (27% PD; HADS-D pre: 11±3; mean change:3±1; p=0.014 vs 13% NS; HADS-D pre: 5±2; mean change: 2±1; p=0.003). PR seems to improve anxiety symptoms, but it might not be as effective for depression symptoms in people with ILD.Future studies are needed to investigate the role of PR in the psychological health of people with ILD.publishe

Seascape configuration leads to spatially uneven delivery of parrotfish herbivory across a Western Indian Ocean seascape

Spatial configuration of habitat types in multihabitat seascapes influence ecological function through links of biotic and abiotic processes. These connections, for example export of organic matter or fishes as mobile links, define ecosystem functionality across broader spatial scales. Herbivory is an important ecological process linked to ecosystem resilience, but it is not clear how herbivory relates to seascape configuration. We studied how herbivory and bioerosion by 3 species of parrotfish were distributed in a multi-habitat tropical seascape in the Western Indian Ocean (WIO). We surveyed the abundance of three species with different life histories—Leptoscarus vaigiensis (seagrass species), Scarus ghobban (juvenile-seagrass/adults-reefs) and Scarus rubroviolaceus (reef species) —in seagrass meadows and on reefs and recorded their selectivity of feeding substrate in the two habitats. Herbivory rates for L. vaigiensis and S. ghobban and bioerosion for S. rubroviolaceus were then modelled using bite rates for different size classes and abundance and biomass data along seascape gradients (distance to alternative habitat types such as land, mangrove and seagrass). Bioerosion by S. rubroviolaceus was greatest on reefs far from seagrass meadows, while herbivory rates by S. ghobban on reefs displayed the opposite pattern. Herbivory in seagrass meadows was greatest in meadows close to shore, where L. vaigiensis targeted seagrass leaves and S. ghobban the epiphytes growing on them. Our study shows that ecological functions performed by fish are not equally distributed in the seascape and are influenced by fish life history and the spatial configuration of habitats in the seascape. This has implications for the resilience of the system, in terms of spatial heterogeneity of herbivory and bioerosion and should be considered in marine spatial planning and fisheries management

Noise exposure and distortion product otoacoustic emission suprathreshold amplitudes : a genome-wide association study

Background: Although several candidate-gene association studies have been conducted to investigate noise-induced hearing loss (NIHL) in humans, most are underpowered, unreplicated, and account for only a fraction of the genetic risk. Mouse genome-wide association studies (GWASs) have revolutionized the field of genetics and have led to the discovery of hundreds of genes involved in complex traits. The hybrid mouse diversity panel (HMDP) is a collection of classic inbred and recombinant inbred strains whose genomes have been either genotyped at high resolution or sequenced. To further investigate the genetics of NIHL, we report the first GWAS based on distortion product otoacoustic emission (DPOAE) measurements and the HMDP. Methods: A total of 102 strains (n = 635) from the HMDP were evaluated based on DPOAE suprathreshold amplitudes before and after noise exposure. DPOAE amplitude variation was set at 60 and 70 dB SPL of the primary tones for each frequency separately (8, 11.3, 16, 22.6, and 32 kHz). These values provided an indirect assessment of outer hair cell integrity. Six-week-old mice were exposed for 2 h to 10 kHz octave-band noise at 108 dB SPL. To perform local expression quantitative trait locus (eQTL) analysis, gene expression microarray profiles were generated using cochlear RNA from 64 hybrid mouse strains (n = 3 arrays per strain). Results: Several new loci were identified and positional candidate-genes associated with NIHL were prioritized, especially after noise exposure (1 locus at baseline and 5 loci after exposure). A total of 35 candidate genes in these 6 loci were identified with at least 1 probe whose expression was regulated by a significant cis-eQTL in the cochlea. After careful analysis of the candidate genes based on cochlear gene expression, 2 candidate genes were prioritized: Eya1 (baseline) and Efr3a (post-exposure). Discussion and Conclusion: For the first time, an association analysis with correction for population structure was used to map several loci for hearing traits in inbred strains of mice based on DPOAE suprathreshold amplitudes before and after noise exposure. Our results identified a number of novel loci and candidate genes for susceptibility to NIHL, especially the Eya1 and Efr3a genes. Our findings validate the power of the HMDP for detecting NIHL susceptibility genes

Dynamics of marine debris ingestion by profitable fishes along the estuarine ecocline

The dynamics of microfilament (<5 mm) ingestion were evaluated in three species of snooks. The ingestion of different colours and sizes of microfilaments were strongly associated with the spatio-temporal estuarine use and ontogenetic shifts of snooks. Their feeding ecology was also analysed to assess dietary relationships with patterns of contamination. All species were highly contaminated with microfilaments. The highest ingestion of microfilaments occurred in the adults, when fishes became the main prey item and also during the peak of fishing activities, in the rainy season. This suggests that trophic transfer, in addition to periods of high availability of microfilaments are important pathways for contamination. The ingestion of microfilaments of different colours and sizes was likely influenced by input sources. Blue microfilaments were frequently ingested, and appear to have both riverine and estuarine inputs, since they were ingested in all seasons and habitats. Purple and red microfilaments were more frequently ingested in the lower estuarine habitats. The length of microfilaments was also associated with environmental variability. Longer microfilaments were ingested in habitats with greater riverine influence, the opposite was observed for shorter microfilaments. Therefore, microfilament contamination in snooks are a consequence of their ecological patterns of estuarine uses through different seasons and life history stages