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Biological extracts have great potential to be used in the synthesis of metallic nanoparticles (M-NPs) due to their variety of biomolecules and different functional groups found in their structure, which act as potential reducing and stabilizing agents. Moreover, is understood as a safer alternative for the environment and health, as it aims to mitigate the use of substance with high toxicity, becoming a more environmentally friendly proposal. In this context, this review emphasizes the influence of the composition of plant extracts, especially extracts that present in their composition biomolecules such as flavonoids, for the synthesis of metallic nanoparticles, focusing on the interactions of the different functional groups found in the structures of flavonoids with metal precursors, to understand the mechanisms of synthesis reaction of metallic nanoparticles. In addition, the use of characterization techniques such as electrochemical, vibrational, morphological and structural is addressed, aiming to understand the potential of biological extracts as reducing and stabilizing agents, as a function of the composition of the extract, and for characterizations of the physicochemical properties of synthesized nanomaterials. Furthermore, the use of metallic nanoparticles as catalysts in the treatment of pollutants, development of electrochemical sensors and biological applications is briefly reported. [ABSTRACT FROM AUTHOR]

Maternal effects can shape the phenotypes of offspring, but the extent to which a layer breeder's experience can affect commercial laying hens remains unclear. We aimed to investigate the effects of maternal age and maternal environment on laying hens' behaviour and stress response. In our first experiment (E1), commercial hybrid hens were reared either in aviary or barren brooding cages, then housed in aviary, conventional cages or furnished (enriched) cages, thus forming different maternal housing treatments. Hens from each treatment were inseminated at three ages, and measures of response to manual restraint and social stress were assessed in offspring. In experiment 2 (E2), maternal age effects on offsprings' stress response were further investigated using fertile eggs from commercial breeder flocks at three ages. In E1, maternal age affected struggling and corticosterone during manual restraint, feather pecking and pulling and comb wounds. Additionally, maternal rearing and housing in aviary systems showed positive effects on measures of behaviour and stress response in offspring. Effects of maternal age were not replicated in E2, possibly due to methodological differences or higher tolerance to maternal effects in commercial breeders. Overall, we recommend researchers report parent stock age to increase comparison across studies and thus our understanding of maternal age effects. [ABSTRACT FROM AUTHOR]

We derive the existence of infinite level GREM-like K-processes by taking the limit of a sequence of finite level versions of such processes as the number of levels diverges. The main step in the derivation is obtaining the convergence of the sequence of underlying finite level clock processes. This is accomplished by perturbing these processes so as to turn them into martingales, and resorting to martingale convergence to obtain convergence for the perturbed clock processes; nontriviality of the limit requires a specific choice of parameters of the original process; we conclude the step by showing that the perturbation washes away in the limit. The perturbation is done by inserting suitable factors into the expression of the clocks, as well as rescaling the resulting expression suitably; the existence of such factors is itself established through martingale convergence. [ABSTRACT FROM AUTHOR]

Early-life exposure to stressors can shape the phenotype of the offspring resulting in changes that may affect their prehatch and posthatch development. This can be modeled indirectly through maternal exposure to stressors (natural model) or by offspring exposure to stress hormones (pharmacological model). In this study, both models were used to investigate the effects of genetic line on hatchability, late embryonic mortality, sex ratio, and body weight until 17 wk of age. To form the parent stock, fertilized eggs of 4 commercial genetic lines —two brown (brown 1 and 2), two white (white 1 and 2), and a pure line White Leghorn — were incubated, hatched, and housed identically in 4 flocks of 27 birds (24 females and 3 males) per strain. Each strain was equally separated into 2 groups: “maternal stress,” where hens were subjected to a series of acute psychological stressors (e.g., physical restraint, transportation) for 8 D before egg collection, and “control,” where hens received routine husbandry. At 3 maternal ages, fertile eggs from both treatments were collected, and additional eggs from the control group were injected with corticosterone (10 ng/mL egg content) (“CORT”). A “vehicle” treatment was included to account for effects of egg manipulation. Each maternal age comprised a replicate over time. Eggs were incubated and hatched, and the offspring (N = 1,919) were brooded until 17 wk under identical conditions. The results show that prenatal stress interacted with strain to decrease embryonic survival and growth. Among all strains, brown 2 was consistently the most affected line in both prehatch and posthatch development. Our study shows that embryonic survival and offspring growth are mostly affected by the pharmacological model and that strain differences may increase susceptibility to prenatal stress. Moreover, it suggests that the natural stressor model may be useful for quantifying the response of the mother to stressors, whereas the pharmacological model may be useful for quantifying the response of the embryo to increased levels of corticosterone. [ABSTRACT FROM AUTHOR]

This is a study of teacher training in dance in the city of Fortaleza from the contribution of Hugo Bianchy dancer and teacher in the 1950s and 1960s. It is a historical research on which we used as a methodological basis the concepts of the New Cultural History (NHC). We also use oral history procedures. Thus, for the collection of information for the understanding of this research, we used oral sources, iconographic and publications on the newspaper The People. The study shows that the dance training in Fortaleza is marked by the 1960s, when Hugo Bianchy deploys her dance academy. We also noticed that there was a concern with the formation of a dance teacher, and yes, with the formation of the artist dancer. [ABSTRACT FROM AUTHOR]

A straightforward methodology for the synthesis of symmetrical thiosulfonates through direct oxidative coupling of thiols is reported. Dibutyl diselenide was suitably applied as a catalyst for the selective conversion of thiols into respective thiosulfonates in good yields. Moreover, mechanistic studies revealed a radical reaction pathway for the preparation of target products. [ABSTRACT FROM AUTHOR]

The effect of electron confinement on the magnetocrystalline anisotropy of ultrathin bcc Fe films is explored by combining photoemission spectroscopy, x-ray magnetic circular dichroism, and magneto-optical Kerr effect measurements. Pronounced thickness-dependent variations in the magnetocrystalline anisotropy are ascribed to periodic changes in the density of states at the Fermi level, induced by quantization of dxz, dyz out-of-plane orbitals. Our results reveal a direct correlation between quantum well states, the orbital magnetic moment, and the magnetocrystalline anisotropy. [ABSTRACT FROM AUTHOR]

Ribbons of nominal composition (Pr9.5Fe84.5B6)0.96Cr0.01(TiC)0.03 were produced by arc-melting and melt-spinning the alloys on a Cu wheel. X-ray diffraction (XRD) reveals two main phases, one based upon α-Fe and the other upon Pr2Fe14B. The ribbons show exchange spring behavior with Hc = 12.5 kOe and (BH)max = 13.6 MGOe when these two phases are well coupled. Transmission electron microscopy revealed the coupled behavior is observed when the microstructure consists predominantly of α-Fe grains (diameter ~100 nm.) surrounded by hard material containing Pr2Fe14B. The microstructure is discussed in terms of a calculation by Skomski and Coey. A first-order-reversal-curve (FORC) analysis was performed for both a well-coupled sample and a poorly coupled sample. The FORC diagrams show two strong peaks for both the poorly coupled sample and for the well-coupled material. In both cases, the localization of the FORC probability suggests magnetizing interactions between particles. Switching field distributions were calculated and are consistent with the sample microstructure. [ABSTRACT FROM AUTHOR]

[Display omitted] • Atomic and continuous scales have been integrated to study ANG deactivation. • The technique was validated with activated carbons experimental data. • Maxsorb activated carbon showed similar performance to the MOF NU-125. • The approach will save experimental effort and bring new property-structure insights. Adsorbed natural gas (ANG) technology could help to facilitate the transition to environmentally friendly automobiles. Limits on total energy storage and the accumulation of higher hydrocarbons (C 3+) present in natural gas are factors that restrict ANG broad application. Because experimental bed deactivation studies are extremely time-consuming, we propose a multiscale technique to study tank deactivation involving a mathematical model capable of predicting compositions of ANG tank cycles. The model is based on multicomponent ideal adsorption solution theory calculation and molecular simulation of the monocomponent adsorption equilibrium data using the representative pore method. We expect that this approach will save experimental effort and bring new insight to understanding the property-structure relation in activated carbons. The technique is validated using literature experimental data from tanks filled with activated carbons. Two target limits for the charge and discharge pressures (35–1 bar and 65–5.8 bar) are tested. The pressure range of 65–5.8 bar shows the best energy delivery for the three commercial carbons examined. The simulation shows that the amount of energy delivered is maximized for a pore size of 18.5 Å, larger than the 11.5 Å pore previously suggested for storage of pure methane. Maxsorb activated carbon showed similar performance to the metal-organic framework (MOF) NU-125 after approximately 100 charge and discharge cycles. In general, activated carbons are less expensive and more stable than MOFs. By accelerating bed deactivation assessment, the technique will allow the synthesis community to produce more efficient carbonaceous materials and facilitate ANG technology feasibility. [ABSTRACT FROM AUTHOR]

• Speciation studies of Cu, Fe, Se and Zn in human milk were conducted by SEC-ICP-MS. • Holder pasteurization did not influence Cu, Fe, Se and Zn contents in human milk. • Protein profiles of human donor milk were affected by Holder pasteurization. • Holder pasteurization caused a little interconversion of Cu, Fe, Se and Zn species. • Apo-proteins rather than holo-proteins are affected by Holder pasteurization. Holder pasteurization is a thermal treatment commonly applied to milk in human milk banks. However, the application of heating processes can affect the actual composition of milk. In this work, the effect of Holder pasteurization on essential elements in donor human breast milk was studied, including total contents and protein-binding profile of Cu, Fe, Se and Zn. The total contents were determined by inductively coupled plasma mass spectrometry (ICP-MS) and chemical speciation studies were conducted by size exclusion chromatography (SEC) coupled to an ICP-MS and to an UV–vis detector. Total concentrations (μg/L) of Cu (0.19 ± 0.01), Fe (0.35 ± 0.01), Se (0.010 ± 0.003) and Zn (0.57 ± 0.01) were obtained before pasteurization and concentrations of Cu (0.19 ± 0.01), Fe (0.36 ± 0.02), Se (0.008 ± 0.002) and Zn (0.57 ± 0.01) were obtained after pasteurization. Their protein-binding profiles did not change significantly for the majority of the species, indicating a low degree of interconversion due to the elevation of the temperature. However, protein profiles changed after pasteurization, indicating that the losses occurred mainly in the apo form (metal-free form) of proteins rather than in their holo forms (metallo-species). [ABSTRACT FROM AUTHOR]

Organic compounds with potential antioxidant activity have attracted special attention of researchers and they have been widely studied in several areas, including pharmacology and medicinal chemistry. In this context, electrochemistry through cyclic voltammetry becomes a fast and efficient tool for the characterization of the antioxidant potential of these compounds. Herein, a study was carried out on the electrochemical behavior of seleno‐dihydropyrimidinones and chloro‐dihydropyrimidinones via cyclic voltammetry in the presence of acetonitrile. By employing this approach, the characterization of the oxidation processes and the determination of antioxidant activities of the target molecules was disclosed. It was also proposed a comparison of the results obtained with the antioxidant activity of the 2,2‐diphenyl‐1‐picrylhydrazyl radical. Among the evaluated compounds, four molecules exhibited significant antioxidant capacities which were efficiently detected by 2,2‐diphenyl‐1‐picrylhydrazyl radical assay and by cyclic voltammetry when measuring the charges transferred until 0.9 V vs Fc+/Fc. [ABSTRACT FROM AUTHOR]

Acetylcholine (ACh) spillover from motor endplates occurs after neuronal firing bursts being potentiated by cholinesterase inhibitors (e.g., neostigmine). Nicotinic α7 receptors (α7nAChR) on perisynaptic Schwann cells (PSCs) can control ACh spillover by unknown mechanisms. We hypothesized that adenosine might be the gliotransmitter underlying PSCs‐nerve terminal communication. Rat isolated hemidiaphragm preparations were used to measure (1) the outflow of [3H]ACh, (2) real‐time transmitter exocytosis by video‐microscopy with the FM4‐64 fluorescent dye, and (3) skeletal muscle contractions during high‐frequency (50 Hz) nerve stimulation bursts in the presence of a selective α7nAChR agonist, PNU 282987, or upon inhibition of cholinesterase activity with neostigmine. To confirm our prediction that α7nAChR‐mediated effects require direct activation of PSCs, we used fluorescence video‐microscopy in the real‐time mode to measure PNU 282987‐induced [Ca2+]i transients from Fluo‐4 NW loaded PSCs in non‐stimulated preparations. The α7nAChR agonist, PNU 282987, decreased nerve‐evoked diaphragm tetanic contractions. PNU 282987‐induced inhibition was mimicked by neostigmine and results from the reduction of ACh exocytosis measured as decreases in [3H]ACh release and FM4‐64 fluorescent dye unloading. Methyllycaconitine blockage of α7nAChR and the fluoroacetate gliotoxin both prevented inhibition of nerve‐evoked ACh release and PSCs [Ca2+]i transients triggered by PNU 282987 and neostigmine. Adenosine deamination, inhibition of the ENT1 nucleoside outflow, and blockage of A1 receptors prevented PNU 282987‐induced inhibition of transmitter release. Data suggest that α7nAChR controls tetanic‐induced ACh spillover from the neuromuscular synapse by promoting adenosine outflow from PSCs via ENT1 transporters and retrograde activation of presynaptic A1 inhibitory receptors. [ABSTRACT FROM AUTHOR]

The ferromagnetic topological insulator V:(Bi,Sb)2Te3 has been recently reported as a quantum anomalous Hall (QAH) system. Yet the microscopic origins of the QAH effect and the ferromagnetism remain unclear. One key aspect is the contribution of the V atoms to the electronic structure. Here the valence band of V:(Bi,Sb)2Te3 thin films was probed in an element-specific way by resonant photoemission spectroscopy. The signature of the V 3d impurity band was extracted and exhibits a high density of states near the Fermi level, in agreement with spin-polarized first-principles calculations. Our results indicate the occurrence of a ferromagnetic superexchange interaction mediated by the observed impurity band, contributing to the ferromagnetism in this system. [ABSTRACT FROM AUTHOR]

We study the electronic structure of a nonsymmorphic Kondo lattice system, CeCuX2 (X = As/Sb), a promising class of correlated topological materials important for advanced technology. While both the materials show Kondo behavior in their transport properties, CeCuSb2 is antiferromagnetic and no magnetic order is observed in CeCuAs2. We studied high-quality single-crystalline samples employing hard x-ray photoemission spectroscopy. The sample cleaving exposes the square-net structured pnictogen layers. The CeCuSb2 valence band indicates a highly metallic phase. The spectral intensity at the Fermi level in CeCuAs2 is weak, revealing close to semi-metallic behavior of the system. The Ce 3d spectra exhibit multiple features; the intensity of the features changes with the change in surface sensitivity of the technique, suggesting significant differences in the surface and bulk electronic structure. The bulk spectra of the Kondo system do not exhibit the typical f0-feature often observed in such materials. Instead, a distinct feature is observed at the lower binding energy side of the well-screened peak; the signature of this feature is manifested in the spectra from high-quality single-crystalline samples. This is outstanding and calls for physics beyond existing theories of correlated systems. [ABSTRACT FROM AUTHOR]

Meloidogyne paranaensis is one of the most destructive root-knot nematode ( RKN) species parasitizing coffee in Brazil and in the Americas generally. The objectives of this study were to assess the genetic variability, aggressiveness and virulence of seven different M. paranaensis populations on susceptible and resistant Coffea spp. All seven RKN populations were identified by biochemical and molecular methods. Coffee seedlings were inoculated in the greenhouse, and the nematode reproduction factor was used to infer their reproduction on coffee genotypes. Phylogenetic studies showed a low genetic variability in M. paranaensis populations, regardless of the existence of three esterase phenotypes (Est P1, P2 and P2a), except for the population Est P2a from Guatemala, which is genetically different from other M. paranaensis populations from Brazil. The Est P2a and Est P2 (Herculândia, SP, Brazil) populations were the most aggressive on two susceptible C. arabica cultivars under greenhouse conditions. None of the M. paranaensis populations were virulent on resistant coffee genotypes, confirming their resistance to the seven M. paranaensis populations tested. The resistant coffee cultivars, namely Clone 14 INCAPER, Catuaí Vermelho × Amphillo MR2161 (E1 16-5 III), Apoatã IAC 2258, Timor Hybrid UFV 408-01 (E1 6-6 II) and IPR 100, exhibited segregation for resistance in the ratio of 0%, 2.4%, 12%, 26% and 29%, respectively. These are promising results, because they validate resistance against several M. paranaensis populations in different Coffea spp. genetic resources, which can be used in breeding programmes or as rootstocks, such as Apoatã IAC 2258 and Clone 14 INCAPER. [ABSTRACT FROM AUTHOR]

The recent realizations of the quantum anomalous Hall effect (QAHE) in MnBi2Te4 and MnBi4Te7 benchmark the (MnBi2Te4)(Bi2Te3)n family as a promising hotbed for further QAHE improvements. The family owes its potential to its ferromagnetically (FM) ordered MnBi2Te4 septuple layers (SLs). However, the QAHE realization is complicated in MnBi2Te4 and MnBi4Te7 due to the substantial antiferromagnetic (AFM) coupling between the SLs. An FM state, advantageous for the QAHE, can be stabilized by interlacing the SLs with an increasing number n of Bi2Te3 quintuple layers (QLs). However, the mechanisms driving the FM state and the number of necessary QLs are not understood, and the surface magnetism remains obscure. Here, robust FM properties in MnBi6Te10 (n = 2) with Tc ≈ 12 K are demonstrated and their origin is established in the Mn/Bi intermixing phenomenon by a combined experimental and theoretical study. The measurements reveal a magnetically intact surface with a large magnetic moment, and with FM properties similar to the bulk. This investigation thus consolidates the MnBi6Te10 system as perspective for the QAHE at elevated temperatures. [ABSTRACT FROM AUTHOR]

The antibacterial activity of ethanol, methanol, hexane and acetone-based extracts of the macroalgae Padina gymnospora (PG), Hypnea musciformes (HM), Ulva fasciata (UF) and Caulerpa prolifera (CP) was investigated. The disk diffusion method was used to evaluate the algae antimicrobial effect against standard strains of Vibrio parahaemolyticus, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Salmonella enterica and five virulent antibiotic-resistant strains of V. brasiliensis, V. xuii and V. navarrensis (isolated from the hemolymph of Litopenaeus vannamei). Ethanol extracts of PG and HM inhibited all Vibrio strains. E. coli and P. aeruginosa were only susceptible to ethanol extracts of PG. Among the methanol extracts, only UF was bioactive, inhibiting V. navarrensis. The observed inhibitory effect of ethanol extracts of PG, HM and UF against virulent antibiotic-resistant bacteria suggests these macroalgal species constitute a potential source of bioactive compounds. [ABSTRACT FROM AUTHOR]

We present a detailed study of the temperature dependence of the electrical resistivity [ρ(T)] in the range 13-300 K for the Ho5(SixGe1-x)4 system. Three distinct ρ(T) behaviors are observed, associated with different magnetic and crystallographic structures along the series. In the samples with an antiferromagnetic phase (AFM) one observes a shoulder near the Néel temperature (TN) attributed to the formation of a gap on the Fermi surface. This gap is analyzed using a phenomenological two-band model for an AFM with distinct atomic and magnetic periodicities, and its effect seems to extend well above TN. We also found the presence of short-range magnetic clusters in the paramagnetic (PM) phase. On the ferromagnetic (FM) materials, the distinct ρ(T) scattering contributions (phonon, magnetic, and residual terms) are extracted from the measurements, with ρ(T) mainly dominated by electron spin scattering. An additional contribution is also observed, arising from the strong crystal field effect in these materials. The effect is mainly observed in the PM phase, leading to a curvature on ρ(T) in this phase. Using a two-level crystal field model the corresponding gap was estimated for the different Si/Ge ratio samples, revealing that the crystal field splitting increases linearly with Si content. [ABSTRACT FROM AUTHOR]

Adsorption processes with activated carbons can be used to remove heavy hydrocarbons from a natural gas flow. Using the Pressure Swing Adsorption (PSA) technology, one can introduce a flexible solution in pre-existing gas-processing units to deal with new marked demands, as for example a C3+ free gas composition to be used as adsorbed natural gas to vehicles fuel tanks. However, designing a PSA process is a laborious task because several cycle configurations and materials are available to perform the separation. To fulfill such task, a multiscale procedure is proposed. Molecular simulation, through Grand Canonical Monte Carlo (GCMC) method, was used to obtain adsorption isotherms for natural gas components in three different carbons: WV-1050, NORIT R1 and MAXSORB. Bed geometry was set based on the minimum fluidization velocity and on the working capacity of the adsorbents. Working capacities were calculated using Langmuir Isotherm applied to Ideal Adsorbed Solution Theory (IAST) to represent the mixture. Each PSA column was simulated in Aspen Adsorption® and operates according to a four steps cycle (Skarstrom cycle): pressurization, adsorption at 40 bar, blowdown, and purge at 1 bar. The operating conditions of the process (such as flowrates, bed geometry and step times) were optimized, seeking the maximization of the process performance parameters: purity, recovery and productivity. A preliminary design of the PSA unit indicates the carbon WV1050 as the best adsorbent to produce C3+ free gas fuel, ideal for storage by adsorption. [ABSTRACT FROM AUTHOR]

Aim: To evaluate artefact intensity in cone beam computed tomography (CBCT) images of two alloys used in metal posts scanned using different exposure parameters. Methodology: The sample consisted of 20 single‐rooted teeth divided into two groups for use with either a NiCr post or AgPd post. All teeth were scanned with and without their corresponding metal posts and with and without the presence of an extra restored tooth in the arch. The samples were scanned using CS 9000 3D scanner with two exposure protocols: 85 kV 6.3 mA and 85 kV 10 mA. Voxel size and FOV were fixed at 0.100 mm and 5 cm × 3.75 cm. The presence of artefacts was assessed qualitatively by two calibrated observers using the CBCT volume and paired 2D images, and quantitatively by one trained observer, using ImageJ software. Wilcoxon's signed rank, Mann–Whitney, kappa and chi‐square tests were used for qualitative analyses. Two‐way anova and Tukey's tests were used for quantitative analyses. All analyses were conducted considering the 95% confidence level (α < 0.05). Results: For the CBCT volume qualitative analysis, significant differences were observed between the metal alloys in the presence of an extra restored tooth, with higher artefact intensity for AgPd when assessing hypodense halos and lines (P = 0.006). Images with two restored teeth had significantly more hypodense and hyperdense lines (P = 0.033). When evaluating exposure parameters and number of restored teeth, the paired image quality analysis revealed significant disagreement between observers for diagnostic image quality (P = 0.001). Quantitative artefact analysis revealed higher artefact intensity for the AgPd posts in the presence of two restored teeth. Conclusion: Although the exposure parameters tested did not interfere with artefact intensity, post alloys with a higher atomic number and the presence of another metal structure in the arch increased artefact intensity and impaired the diagnostic quality of CBCT images. [ABSTRACT FROM AUTHOR]

Although Brazil is the centre with the third highest diversity of Cactaceae, the distribution of species at the local scale in Brazil remains largely unknown. This article describes the distribution patterns of the Cactaceae communities in the protected area of the Contendas do Sincorá National Forest (CSNF) in a semiarid region in the north-east of Brazil. Trails were distributed between the altitudes of 290 and 596 m, along which 91 plots (1.8 ha) were established for quantitative surveys. The floristic data were also recorded separately on these trails. With the floristic survey, 18 taxa were recorded, and the quantitative surveys within the plots identified 10 species, represented by 1135 individuals. The distribution patterns of the species of Cactaceae were intermittent, which provided a likely explanation for the differences between the floristic survey and the species composition of the plots. The largest fraction of the floristic variation was not explained by environment or space, and this may be related to climatic alterations in the past, evolutionary processes, natural and anthropic disturbances and other unmeasured environmental variables. The recorded endemic, vulnerable and endangered species of the caatingas of Bahia indicate that broader protection areas for the Cactaceae species in the region of the CSNF are necessary. [ABSTRACT FROM AUTHOR]

The mollusc Anomalocardia brasiliana is sensitive to environmental variations with high mortality due to rains. In the state of Pernambuco, among the species of larger fisheries production, this clam has great economic importance. The study aimed to evaluate the remaining population of A. brasiliana of beach Mangue Seco, during the rainy and dry season, after the capture by fishermen and three moments of sampling. In evaluation of data three factors were considered: period; type of extraction and moment of sampling. Response variables analysed were total length and total number of animals sampled. The study was conducted in August 2009, after the rainy season, and in January 2010, the dry season in northeastern Brazil. The amount of captured animals with recommended size for fishing (> 20 mm) was above 80% in August, and below 20% in January. There was no significant difference between the sizes of the animals collected. The rainy season in northeastern Brazil influences the population of A. brasiliana, causing reduction in the number of clams, however, at this time of year there is a higher frequency of adults. [ABSTRACT FROM AUTHOR]

Accessions of Gossypium spp., some of them never previously tested, were evaluated for resistance to a local isolate of Meloidogyne incognita race 3 in greenhouse experiments. Nematode infection was characterized based on the galling and egg mass indexes and the reproduction factors ( RF). Root-knot nematode reproduction among the newly tested accessions varied from highly susceptible ( AS0188, AS0189) to moderately resistant ( MT123 no. 3), and some accessions showed highly reduced nematode reproduction ( CIR1343, CIR1348, Fai Mui). Histological observations of two resistant accessions ( G. barbadense CIR1348 and G. hirsutum TX-25, respectively) showed that resistance occurs through a two-stage mechanism in the first accession and through a single-stage mechanism in the second. Parasitism is blocked early after second-stage juvenile (J2) penetration or during its initial tissue migration ( CIR1348) and the development of later-stage juveniles into female adults is suppressed at a later stage ( TX-25 and CIR1348). Fluorescence and bright light microscopy showed that root cells surrounding nematodes exhibit a hypersensitivity-like reaction, with the accumulation of presumably phenolic compounds and the presence of necrotic cells that limit the development of nematodes and the formation of giant cells. Underdeveloped giant cells with degenerated cytoplasmic content were found in small numbers in CIR1348 and in large numbers in TX-25, along with deformed nematodes. The full characterization of the defence mechanisms of novel sources of resistance to the root-knot nematode in cotton constitutes a first step towards their use in crop improvement. [ABSTRACT FROM AUTHOR]

The problem of predicting the adsorptive properties of activated carbon (AC) towards a mixture of gases from the simple knowledge of the adsorption properties of the pure components is addressed, with special reference to the CO2/CH4 mixture. The adsorption process for the pure gases and their mixtures was simulated using the Grand Canonical Monte Carlo (GCMC) method and the calculations were then used to analyze experimental isotherms for the pure gases and for mixtures with different molar fractions in the gaseous phase. It was shown that the pore-size distributions (PSDs) "sensed" by each of the pure probe gases was different one from the other and also from the PSDs "seen" by the mixture. A mixing rule for combining the PSDs corresponding to the pure gases is proposed for obtaining predictions regarding the adsorption of the corresponding mixtures, which are then compared with those arising from the classical IAST approximation. For this purpose, selectivity curves for CO2 relative to CH4 have been calculated and compared with experimental values. It was concluded that, for the adsorbate/adsorbent system under study, the proposed GCMC mixed model was capable of predicting the binary adsorption equilibrium, and especially the selectivity, more accurately than the IAST. [ABSTRACT FROM AUTHOR]

The clam Anomalocardia brasiliana presents great economic and social importance in the artisan fishing of the north coast of Pernambuco, Brazil. This study aimed to examine the aspects related to the reproductive biology of the natural stock of A. brasiliana in Mangue Seco beach, Municipality of Igarassu, north coast of Pernambuco, Brazil. The reproductive biology of the species was monthly monitored for ten months by histological characterization of the gonadal development, yield (condition index) and sex ratio calculation. The yield and histology analysis results indicated that the species has the potential to reproduce continuously during the study period. These results may be used as a basis for establishing future fisheries management programs and for the development of clam aquaculture in the region. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the role of killer cell immunoglobulin-like receptor ( KIR) genes in leprosy immunopathogenesis. Genotyping of KIR and human leukocyte antigen ( HLA) genes was performed by polymerase chain reaction with sequence-specific oligonucleotide probes in 165 leprosy patients. Both activating KIR2DS2 and KIR2DS3 frequencies were higher in tuberculoid leprosy (TT) patients than in lepromatous leprosy (LL) patients, and the inhibitory KIR with its ligand, KIR2DL1-C2/C2, was elevated in TT patients in comparison to all other leprosy subgroups and controls. However, a negative association between KIR2DL3-C1 and KIR2DL3-C1/C1 and the TT group was identified. Borderline patients exhibited a higher frequency of KIR3DL2-A3/11 than the controls and LL patients, and a lower frequency of KIR2DL1-C2 than the controls and TT subgroup. Some KIR–HLA genotypes could be associated to the development of clinical forms of leprosy and should be investigated further. [ABSTRACT FROM AUTHOR]

The Azores, a Portuguese archipelago located in the north Atlantic Ocean, had no native population when the Portuguese first arrived in the 15th century. The islands were populated mainly by the Portuguese, but Jews, Moorish prisoners, African slaves, Flemish, French and Spaniards also contributed to the initial settlement. To understand the paternal origins and diversity of the extant Azorean population, we typed genomic DNA samples from 172 individuals using a combination of 10 Y-biallelic markers (YAP, SRY-1532, SRY-2627, 92R7, M9, sY81, Tat, SRY-8299, 12f2 and LLY22g) and the following Y-chromosomal STR systems: DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393 and DYS385. We identified nine different haplogroups, most of which are frequent in Europe. Haplogroup J* is the second most frequent in the Azores (13.4%), but it is modestly represented in mainland Portugal (6.8%). The other non-European haplogroups, N3 and E3a, which are prevalent in Asia and sub-Saharan Africa, respectively, have been found in the Azores (0.6% and 1.2%, respectively) but not in mainland Portugal. Microsatellite data indicate that the mean gene diversity (D) value for all the loci analysed in our sample set is 0.590, while haplotype diversity is 0.9994. Taken together, our analysis suggests that the current paternal pool of the Azorean population is, to a great extent, of Portuguese descent with significant contributions from people with other genetic backgrounds. [ABSTRACT FROM AUTHOR]

We have identified a silencer and an antisilencing element that interact at a distance of 85 kilobases to regulate expression of the recombination activating genes Rag1 and Rag2 in thymocytes. Transgenic experiments showed that Rag promoter-proximal cis elements directed tissue-specific expression and that a Runx-dependent intergenic silencer suppressed expression in developing T cells. Deletion of the antisilencing element from the genomic Rag locus unmasked the intergenic silencer and abrogated Rag expression in developing CD4+CD8+ T cells. We speculate that the Rag antisilencing element belongs to a class of cis elements that might be useful for genome diversification by activating genes encoded by otherwise silent transposable elements. [ABSTRACT FROM AUTHOR]

Using angle-resolved photoelectron spectroscopy (ARPES), we investigate the surface electronic structure of the magnetic van der Waals compounds MnBi4Te7 and MnBi6Te10, the n=1 and 2 members of a modular (Bi2Te3)n(MnBi2Te4) series, which have attracted recent interest as intrinsic magnetic topological insulators. Combining circular dichroic, spin-resolved and photon-energy-dependent ARPES measurements with calculations based on density functional theory, we unveil complex momentum-dependent orbital and spin textures in the surface electronic structure and disentangle topological from trivial surface bands. We find that the Dirac-cone dispersion of the topologial surface state is strongly perturbed by hybridization with valence-band states for Bi2Te3-terminated surfaces but remains preserved for MnBi2Te4-terminated surfaces. Our results firmly establish the topologically nontrivial nature of these magnetic van der Waals materials and indicate that the possibility of realizing a quantized anomalous Hall conductivity depends on surface termination. [ABSTRACT FROM AUTHOR]

Methylmercury (MeHg+) is a mercury species that is very toxic for humans, and its monitoring and sorption from environmental samples of water are a public health concern. In this work, a combination of theory and experiment was used to rationally synthesize an ion-imprinted polymer (IIP) with the aim of the extraction of MeHg+ from samples of water. Interactions among MeHg+ and possible reaction components in the pre-polymerization stage were studied by computational simulation using density functional theory. Accordingly, 2-mercaptobenzimidazole (MBI) and 2-mercaptobenzothiazole (MBT), acrylic acid (AA) and ethanol were predicted as excellent sulfhydryl ligands, a functional monomer and porogenic solvent, respectively. Characterization studies by scanning electron microscopy (SEM) and Brunauer–Emmett–Teller (BET) revealed the obtention of porous materials with specific surface areas of 11 m2 g−1 (IIP–MBI–AA) and 5.3 m2 g−1 (IIP–MBT–AA). Under optimized conditions, the maximum adsorption capacities were 157 µg g−1 (for IIP–MBI–AA) and 457 µg g−1 (for IIP–MBT–AA). The IIP–MBT–AA was selected for further experiments and application, and the selectivity coefficients were MeHg+/Hg2+ (0.86), MeHg+/Cd2+ (260), MeHg+/Pb2+ (288) and MeHg+/Zn2+ (1510), highlighting the material's high affinity for MeHg+. The IIP was successfully applied to the sorption of MeHg+ in river and tap water samples at environmentally relevant concentrations. [ABSTRACT FROM AUTHOR]

A comprehensive understanding of spin-polarized photoemission is crucial for accessing the electronic structure of spin-orbit coupled materials. Yet, the impact of the final state in the photoemission process on the photoelectron spin has been difficult to assess in these systems. We present experiments for the spin-orbit split states in a Bi-Ag surface alloy showing that the alteration of the final state with energy may cause a complete reversal of the photoelectron spin polarization. We explain the effect on the basis of ab initio one-step photoemission theory and describe how it originates from linear dichroism in the angular distribution of photoelectrons. Our analysis shows that the modulated photoelectron spin polarization reflects the intrinsic spin density of the surface state being sampled differently depending on the final state, and it indicates linear dichroism as a natural probe of spin-orbit coupling at surfaces. [ABSTRACT FROM AUTHOR]