Effect of triplet encapsulated atoms in [60] fullerenes: a theoretical analysis

The present investigation reports on the interaction of the C/O triplet atoms inside of the [60] fullerene (C60) species with small polar molecules (H²O, CH³OH, HF, NH³) using Density Functional Theory (DFT) calculations. The calculations show that in all the computed cases the encapuslated complexes with the molecules are more stable than without internal atoms.

Flow injection visible diffuse reflectance quantitative analysis of total sulfur in biodiesel, in plant leaves and in natural waters

Flow injection (FI) methodology, using diffuse reflectance in the visible region of the spectrum, for the analysis of total sulfur in the form of sulfate, precipitated in the form of barium sulfate, is presented. The method was applied to biodiesel, to plant leaves and to natural waters analysis. The analytical signal (S) correlates linearly with sulfate concentration (C) between 20 and 120 ppm, through the equation S=-1.138+0.0934 C (r = 0.9993). The experimentally observed limit of detection is about 10 ppm. The mean R.S.D. is about 3.0 %. Real samples containing sulfate were analyzed and the results obtained by the FI and by the reference batch turbidimetric method using the statistical Student's t-test and F-test were compared.

Flow-batch analyser for preparation of calibration standard mixtures in simultaneous multicomponent spectrometric analysis

The application of multivariate calibration techniques to multicomponent analysis by UV-VIS molecular absorption spectrometry is a powerful tool for simultaneous determination of several chemical species. However, when this methodology is accomplished manually, it is slow and laborious, consumes high amounts of reagents and samples, is susceptible to contaminations and presents a high operational cost. To overcome these drawbacks, a flow-batch analyser is proposed in this work. This analyser was developed for automatic preparation of standard calibration and test (or validation) mixtures. It was applied to the simultaneous determination of Cu2+, Mn2+ and Zn2+ in polyvitaminic and polymineral pharmaceutical formulations, using 4-(2-piridilazo) resorcinol as reagent and a UV-VIS spectrophotometer with a photodiode array detector. The results obtained with the proposed system are in good agreement with those obtained by flame atomic absorption spectrometry, which was employed as reference method. With the proposed analyser, the preparation of calibration and test mixtures can be accomplished about four hours, while the manual procedure requires at least two days. Moreover, it consumes smaller amounts of reagents and samples than the manual procedure. After the preparation of calibration and test mixtures, 60 samples h-1 can be carried out with the proposed flow-batch analyser.

Spot-test identification and rapid quantitative sequential analysis of dipyrone

A qualitative spot-test and tandem quantitative analysis of dipyrone in the bulk drug and in pharmaceutical preparations is proposed. The formation of a reddish-violet color indicates a positive result. In sequence a quantitative procedure can be performed in the same flask. The quantitative results obtained were statistically compared with those obtained with the method indicated by the Brazilian Pharmacopoeia, using the Student's t and the F tests. Considering the concentration in a 100 µL aliquot, the qualitative visual limit of detection is about 5×10-6 g; instrumental LOD ≅ 1.4×10-4 mol L-1 ; LOQ ≅ 4.5×10-4 mol L-1.

A pH optode based on thymol blue: application to determination of CO2 using flow injection analysis system

An optode based on thymol blue (TB), an acid-based indicator, has been constructed and evaluated as a detector in FIA system for CO2 determination. The dye was chemically immobilised on the surface of a bifurcated glass optical fibre bundle, using silanisation in organic media. In FIA system, hydrogen carbonate or carbonate samples are injected in a buffer carrier solution, and then are mixed with phosphoric acid solution to generate CO2, which diffuses through a PTFE membrane, in order to be collected in an acceptor carrier fluid, pumped towards to detection cell, in which the optode was adapted. The proposed system presents two linear response ranges, from 1.0 x 10-3 to 1.0 x 10-2 mol l-1, and from 2.0 x 10-2 to 0.10 mol l-1. The sampling frequency was 11 sample h-1, with good repeatability (R.S.D < 4 %, n = 10). In flow conditions the optode lifetime was 170 h. The system was applied in the analysis of commercial mineral water and the results obtained in the hydrogen carbonate determination did not differ significantly from those obtained by potentiometry, at a confidence level of 95 %.

Potentiometric and conductimetric studies of chemical equilibria for pyridoxine hydrochloride in aqueous solutions: simple experimental determination of pKa values and analytical applications to pharmaceutical analysis

The combination of two low-cost classical procedures based on titrimetric techniques is presented for the determination of pyridoxine hydrochloride in pharmaceuticals samples. Initially some experiments were carried out aiming to determine both pKa1 and pKa2 values, being those compared to values of literature and theoretical procedures. Commercial samples containing pyridoxine hydrochloride were electrochemically analysed by exploiting their acid-base and precipitation reactions. Potentiometric titrations accomplished the reaction between the ionizable hydrogens present in pyridoxine hydrochloride, being NaOH used as titrant; while the conductimetric method was based on the chemical precipitation between the chloride of pyridoxine hydrochloride molecule and Ag+ ions from de silver nitrate, changing the conductivity of the solution. Both methods were applied to the same commercial samples leading to concordant results when compared by statistical tests (95 and 98% confidence levels). Recoveries ranging from 99.0 to 108.1% were observed, showing no significant interference on the results.

Phylogenetic analysis of Tomato mosaic virus from Hemerocallis sp. and Impatiens hawkeri

The culture and commercialization of ornamental plants have considerably increased in the last years. To supply the commercial demand, several Hemerocallis and Impatiens varieties have been bred for appreciated qualities such as flowers with a diversity of shapes and colors. With the aim of characterizing the tobamovirus isolated from Hemerocallis sp. (tobamo-H) and Impatiens hawkeri (tobamo-I) from the USA and São Paulo, respectively, as well as to establish phylogenetic relationships between them and other Tobamovirus species, the viruses were submitted to RNA extraction, RT-PCR amplification, coat-protein gene sequencing and phylogenetic analyses. Comparison of tobamovirus homologous sequences yielded values superior to 98.5% of identity with Tomato mosaic virus (ToMV) isolates at the nucleotide level. In relation to tobamo-H, 100% of identity with ToMV from tomatoes from Australia and Peru was found. Based on maximum likelihood (ML) analysis it was suggested that tobamo-H and tobamo-I share a common ancestor with ToMV, Tobacco mosaic virus, Odontoglossum ringspot virus and Pepper mild mottle virus. The tree topology reconstructed under ML methodology shows a monophyletic group, supported by 100% of bootstrap, consisting of various ToMV isolates from different hosts, including some ornamentals, from different geographical locations. The results indicate that Hemerocallis sp. and I. hawkeri are infected by ToMV. This is the first report of the occurrence of this virus in ornamental species in Brazil.

Lärande som text : en dramapedagogiskt förankrad läsning av det kroppsliga, rumsliga och retoriska i kunskapsbildande processer

My presupposition, that learning at some level deals with life praxis, is expressed in four metaphors: space, time, fable and figure. Relations between learning,knowledge building and meaning making are linked to the concept of personal knowledge. I present a two part study of learning as text in a drama pedagogical rooted reading where learning is framed as the ongoing event, and knowledge, as the product of previous processes, is framed as culturally formed utterances. A frame analysis model is constructed as a topological guide for relations between the two concepts learning and knowledge. It visualises an aesthetic understanding, rooted in drama pedagogical comprehension. Insight and perception are linked in an inner relationship that is neither external nor identical. This understanding expresses the movement "in between" connecting asymmetrical and nonlinear features of human endeavour and societal issues. The performability of bodily and oral participation in the learning event in a socio-cultural setting is analysed as a dialogised text. In an ethnographical case study I have gathered material with an interest for the particular. The empirical material is based on three problem based learning situations in a Polytechnic setting. The act of transformation in the polyphony of the event is considered as a turning point in the narrative employment. Negotiation and figuration in the situation form patterns of the space for improvisation (flow) and tensions at the boundaries (thresholds) which imply the logical structure of transformation. Learning as a dialogised text of "yes" and "no", of structure and play for the improvised, interrelate in that movement. It is related to both the syntagmic and the paradigmatic forms of thinking. In the philosophical study, forms of understanding are linked to the logical structure of transformation as a cultural issue. The classical rhetorical concepts of Logos, Pathos, Ethos and Mythos are connected to the multidimensional rationality of the human being. In the Aristotelian form of knowledge, phronesis,a logic structure of inquiry is recognised. The shifting of perspectives between approaches, the construction of knowledge as context and the human project of meaning making as a subtext, illuminates multiple layers of the learning text. In an argumentation that post-modern apprehension of knowledge, emphasising contextual and situational values, has an empowering impact on learning, I find pedagogical benefits. The dialogical perspective has opened lenses that manage to hold in aesthetic doubling the individual action of inquiry and the stage with its cultural tools in a three dimensional reading.

An analysis of the risk of cocoa moniliasis occurrence in Brazil as the result of climate change

The aim of this study was to evaluate the potential risk of moniliasis occurrence and the impacts of climate change on this disease in the coming decades, should this pathogen be introduced in Brazil. To this end, climate favorability maps were devised for the occurrence of moniliasis, both for the present and future time. The future scenarios (A2 and B2) focused on the decades of 2020, 2050 and 2080. These scenarios were obtained from six global climate models (GCMs) made available by the third assessment report of Intergovernmental Panel on Climate Change (IPCC). Currently, there are large areas with favorable climate conditions for moniliasis in Brazil, especially in regions at high risk of introduction of that pathogen. Considering the global warming scenarios provided by the IPCC, the potential risk of moniliasis occurrence in Brazil will be reduced. This decrease is predicted for both future scenarios, but will occur more sharply in scenario A2. However, there will still be areas with favorable climate conditions for the development of the disease, particularly in Brazil's main producing regions. Moreover, pathogen and host alike may undergo alterations due to climate change, which will affect the extent of their impacts on this pathosystem.

Stability of Citrus tristeza virus protective isolate 'Pêra IAC' according to SSCP analysis of old and new lines of three sweet orange varieties

Clonal cleaning, followed by pre-immunization with protective complexes of Citrus tristeza virus(CTV), allowed the commercial cultivation of Pêra sweet orange, a variety that has great importance for Brazilian citriculture but is sensitive to the virus. The use of mild protective isolates in other citrus varieties, even those more tolerant to CTV, can also be of interest to prevent the spread of severe isolates. The aim of this study was to characterize, by means of SSCP (Single Strand Conformational Polymorphism) analysis of the coat protein gene, CTV isolates present in plants of the sweet orange cultivars Pêra, Hamlin and Valencia propagated from four budwood sources: 1) old lines, 2) nucellar lines, 3) shoot-tip-grafted lines, and 4) shoot-tip-grafted lines pre-immunized with the mild CTV protective isolate 'PIAC'. We also evaluated the correlation of the obtained SSCP patterns to stem pitting intensity, tree vigor and fruit yield. SSCP results showed low genetic diversity among the isolates present in different trees of the same variety and same budwood source and, in some cases, in different budwood sources and varieties. Considering tristeza symptoms, lower intensity was noted for plants of new, shoot-tip-grafted and pre-immunized shoot-tip-grafted lines, compared to old lines of the three varieties. The observed SSCP patterns and symptomatology suggested that more severe CTV complexes infect the plants of old lines of all three varieties. The protective complex stability was observed in the SSCP patterns of CTV isolates of some shoot-tip-grafted and pre-immunized clones. It was concluded that the changes detected in other electrophoretic profiles of this treatment did not cause loss of the protective capacity of CTV isolate 'PIAC' inoculated in the pre-immunization.

Harvesting and wood transport planning with SNAP III program (Scheduling and Network Analysis Program) in a pine plantation in Southeast Brazil

The objective of this study was to verify the potential of SNAP III (Scheduling and Network Analysis Program) as a support tool for harvesting and wood transport planning in Brazil harvesting subsystem definition and establishment of a compatible route were assessed. Initially, machine operational and production costs were determined in seven subsystems for the study area, and quality indexes, construction and maintenance costs of forest roads were obtained and used as SNAP III program input data. The results showed, that three categories of forest road occurrence were observed in the study area: main, secondary and tertiary which, based on quality index, allowed a medium vehicle speed of about 41, 30 and 24 km/hours and a construction cost of about US$ 5,084.30, US$ 2,275.28 and US$ 1,650.00/km, respectively. The SNAP III program used as a support tool for the planning, was found to have a high potential tool in the harvesting and wood transport planning. The program was capable of defining efficiently, the harvesting subsystem on technical and economical basis, the best wood transport route and the forest road to be used in each period of the horizon planning.

RAPD analysis of genetic variability in a multiprovenance base population of Eucalyptus grandis hill ex maiden

This study aimed to evaluate the genetic variability among individuals of a base population of Eucalyptus grandis and to build a molecular marker database for the analyzed populations. The Eucalyptus grandis base population comprised 327 individuals from Coff's Harbour, Atherton and Rio Claro. A few plants came from other sites (Belthorpe MT. Pandanus, Kenilworth, Yabbra, etc.). Since this base population had a heterogeneous composition, the groups were divided according to geographic localization (latitude and longitude), and genetic breeding level. Thus, the influence of those two factors (geographic localization and genetic breeding level) on the genetic variability detected was discussed. The RAPD technique allowed the evaluation of 70 loci. The binary matrix was used to estimate the genetic similarity among individuals using Jaccard's Coefficient. Parametric statistical tests were used to compare within-group similarity of the means. The obtained results showed that the base population had wide genetic variability and a mean genetic similarity of 0.328. Sub-group 3 (wild materials from the Atherton region) showed mean genetic similarity of 0.318. S.P.A. (from Coff's Harbour region) had a mean genetic similarity of 0.322 and was found to be very important for maintenance of variation in the base population. This can be explained since the individuals from those groups accounted for most of the base population (48.3% for it). The base population plants with genetic similarity higher than 0.60 should be phenotypically analyzed again in order to clarify the tendency of genetic variability during breeding programs.

Analysis of private natural heritage reserves as a conservation strategy for the biodiversity of the cocoa region of the southern State of Bahia, Brazil

Brazil was the first country in Latin America to establish and regulate this type of reserve, and there are currently more than 700 Private Nature Heritage Reserves (RPPN in Portuguese) officially recognized by either federal or state environmental agencies. Together, these RPPN protect more than a half million hectares of land in the country. The coastal forests in the southern part of Bahia State extend 100 to 200 km inland, gradually changing in physiognomy as they occupy the dryer inland areas. The coastal forest has been subjected to intense deforestation, and currently occupies less than 10% of its original area. For this work the creation processes of the RPPN were consulted to obtain the data creation time, size of property, the condition of the remaining forest, succession chain and the last paid tax. After that, interviews with the owners were made to confirm this data. Sixteen RPPN have been established in this region until 2005. Their sizes vary from 4.7 to 800 ha. Ten of these RPPN are located within state or federal conservation areas or their buffer zones. In spite of the numerous national and international conservation strategies and environmental policies focused on the region, the present situation of the cocoa zone is threatening the conservation of the region's natural resources. The establishment of private reserves in the cocoa region could conceivably improve these conservation efforts. This type of reserve can be established under a uniform system supported by federal legislation, and could count on private organizations.

Ultrastructural calli analysis of Inga vera Willd. subsp. Affinis (DC.) T.D. Penn

Subcellular changes are relevant to understand plant organogenesis and embryogenesis in the early stages of cell development. The cytology during cell development in tissue culture is however still poorly characterized. This study aimed to characterize the ultrastructural differences related to callogenesis of anthers, ovaries, leaf and nodal segments of Inga vera Willd. subsp. Affinis (DC.) T.D. Penn. Flower buds, nodal segments and leaves were disinfected and inoculated in test tubes containing MS medium with 3% sucrose and 4.5µM 2.4-D, except for leaf callogenesis, where 9µM of this auxin was used, and for the callogenesis of anthers and ovaries, where the culture medium was enriched with 0.25% activated charcoal and 90µM PVP. After 45 days in culture medium, the anther, ovary, leaf and nodal segment calli were fixed in Karnovisky and prepared for visualization by scanning and transmission electron microscopy. Ultrastructural differences were observed among the callus cells of anthers, ovaries, segments and leaves. There was no evidence of somatic embryo formation in the anther, leaf and nodal segment calli, in spite of some embryogenic characteristics in the cells. The ovary calli, with indications of embryo formation, seem to be the most responsive explant source for embryogenesis.

”They Call it Christmas”. An Ethnological Analysis of Alienation in Tove Jansson’s Short Story The Fir Tree

Artikel i tidskrift med referee-praxis