Atlantic seabob shrimp as biomonitor of Cu and Zn near port activities: is it really a suitable choice?

The trace elements concentration in the muscle of the Atlantic seabob shrimp (Xiphopenaeus kroyeri) caught in coastal fishing highlighted copper (Cu) and zinc (Zn), both related to antifouling systems, as the main elements related to the intensity of port activities of southeast Brazil (~20—to 22ºS). The aim of this study is to analyze if the behavior of Cu and Zn in the muscle of this shrimp species is constant among different sampling sites, verifying if the species is suitable as biomonitor for these elements. The shrimps came from fisheries done in 2017 in Vitória, Anchieta, and Farol de São Tomé, southeast Brazil. After sampling, each individual was categorized for gender and maturity stage, measured, and weighted. Bulk muscle samples were freeze-dried for determination of Cu, Zn, and ratios of stable isotopes of carbon (δ13C) and nitrogen (δ15N). The data analysis verified if the concentration of Cu and Zn in male and female shrimps vary among maturity stages and sampling sites, and how the concentration of Cu and Zn is related to shrimps foraging area and/or trophic position. Both bioaccumulation and growth dilution occurred, but not in the same way for genders and sampling sites, with Cu showing more variability. Relationships between elements and shrimps foraging area and trophic position did not show a clear trend among the sampling sites. Regression models indicated moderate relationships, explaining 51% (Cu) and 60% (Zn) of the association with the foraging area in Anchieta, but up to 8% in Vitória and Farol de São Thomé. For the trophic position, the models explained 33% (Cu) and 34% (Zn) in Anchieta and up to 14% in Vitória and Farol de São Thomé. The results showed that the utilization of this shrimp species as biomonitor of marine coastal environments near port activities to monitoring the levels of Cu and Zn is not a suitable choice, at least in the spatial scale considered by this study.

The Rescaled Pólya Urn and the Wright–Fisher Process with Mutation

In recent papers the authors introduce, study and apply a variant of the Eggenberger–Pólya urn, called the “rescaled” Pólya urn, which, for a suitable choice of the model parameters, exhibits a reinforcement mechanism mainly based on the last observations, a random persistent fluctuation of the predictive mean and the almost sure convergence of the empirical mean to a deterministic limit. In this work, motivated by some empirical evidence, we show that the multidimensional Wright–Fisher diffusion with mutation can be obtained as a suitable limit of the predictive means associated to a family of rescaled Pólya urns.

Lignocellulosic Bioethanol and Biobutanol as a Biocomponent for Diesel Fuel

In this paper, the fuel properties of mixtures of diesel fuel and ethanol and diesel fuel and butanol in the ratio of 2.5% to 30% were investigated. The physicochemical properties of the blends such as the cetane number, cetane index, density, flash point, kinematic viscosity, lubricity, CFPP, and distillation characteristics were measured, and the effect on fuel properties was evaluated. These properties were compared with the current EN 590+A1 standard to evaluate the suitability of the blends for use in unmodified engines. The alcohols were found to be a suitable bio-component diesel fuel additive. For most physicochemical properties, butanol was found to have more suitable properties than ethanol when used in diesel engines. The results show that for some properties, a butanol–diesel fuel mixture can be mixed up to a ratio of 15%. Other properties would meet the standard by a suitable choice of base diesel.

Properties of Bonding Sealants in the Sealing of Cement-Based Materials

This paper describes the issue of sealing cement-based materials. These materials can also include concrete elements or cement fiber boards. For the purposes of this work, a cement fiber material is selected, namely glass. This material has good effects in terms of small dust particles on the surface, which damage the bonding sealant and the substrate. Focus on its suitability for sealing cement-based substrates. The method for determining the properties of the sealant and the properties of the stylistic joint between the sealant and the base material is the tensile test. For the purpose of this test, one representative of neutral silicones, one representative of acetate silicones and one representative for acrylic sealants shall be selected. From the results of the tensile test, it is clear that with a suitable choice of the combination of bonding sealant and primer, it is possible to seal such a problematic substrate with good results.

Iridium(NHC)-Catalyzed Sustainable Transfer Hydrogenation of CO2 and Inorganic Carbonates

Iridium(NHC)-catalyzed transfer hydrogenation (TH) of CO2 and inorganic carbonates with glycerol were conducted, demonstrating excellent turnover numbers (TONs) and turnover frequencies (TOFs) for the formation of formate and lactate. Regardless of carbon sources, excellent TOFs of formate were observed (CO2: 10,000 h−1 and K2CO3: 10,150 h−1). Iridium catalysts modified with the triscarbene ligand showed excellent catalytic activity at 200 °C and are a suitable choice for this transformation which requires a high temperature for high TONs of formate. On the basis of the control experiments, the transfer hydrogenation mechanism of CO2 was proposed.

#Ledatoo: The morality of Leda and the Swan in teaching stylistics

The article discusses the morality of W. B. Yeats’ sonnet Leda and the Swan in the context of a widening gap between the sexual mores of earlier times and our own, and whether the poem remains a suitable choice for the teaching of stylistics. I begin by examining stylistics treatments of the poem, and its political, social and artistic context, then move on to consider charges of misogyny against the poem for eroticising and failing to condemn the rape it depicts. To assess these charges I examine other literary uses of the Leda myth both before and after Yeats, including earlier poems which romanticise the rape, and later ones which vilify it. I also consider the implications of my discussion for the teaching of other canonical poems on similar themes. The last part of the paper discusses more generally the place of morality in literature and literature teaching, including stylistics: whether teachers and analysts should promote a moral world view and moral behaviour through their choice of texts and comments on them, or whether there are other valid criteria for selecting and describing a text such as Leda and the Swan. To elucidate current views, I draw parallels with the moral didacticism of the highly influential literary critic F. R. Leavis in the mid twentieth century, and ask whether aspects of his patrician view have undergone a surreptitious revival in some contemporary pedagogy and criticism at the beginning of the twenty first.

Dynamics at Infinity and Existence of Singularly Degenerate Heteroclinic Cycles in Maxwell–Bloch System

In this paper, global dynamics of the Maxwell–Bloch system is discussed. First, the complete description of its dynamic behavior on the sphere at infinity is presented by using the Poincaré compactification in R3. Second, the existence of singularly degenerate heteroclinic cycles is investigated. It is proved that for a suitable choice of the parameters, there is an infinite set of singularly degenerate heteroclinic cycles in Maxwell–Bloch system. Specially, the chaotic attractors are found nearby singularly degenerate heteroclinic cycles in Maxwell–Bloch system by combining theoretical and numerical analyses for a special parameter value. It is hoped that these theoretical and numerical value results are given a contribution in an understanding of the physical essence for chaos in the Maxwell–Bloch system.