Non-linear pathways of corporate environmental management: a survey of ISO 14001-certified companies in Brazil

A study was conducted to verify whether the theory on the evolution of corporate environmental management (CEM) is applicable to organizations located in Brazil. Some of the most important proposals pertaining to the evolution of CEM were evaluated in a systematic fashion and integrated into a typical theoretical framework containing three evolutionary stages: reactive, preventive and proactive. The validity of this framework was tested by surveying 94 companies located in Brazil with ISO 14001 certification. Results indicated that the evolution of CEM tends to occur in a manner that is counter to what has generally been described in the literature. Two evolutionary stages were identified: 1) synergy for eco-efficiency and 2) environmental legislation view, which combine variables that were initially categorized into different theoretical CEM stages. These data, obtained from a direct study of Brazilian companies, suggest that the evolution of environmental management in organizations tends to occur in a non-linear fashion, requiring a re-analysis of traditional perceptions of CEM development, as suggested by Kolk and Mauser (2002). (C) 2010 Elsevier Ltd. All rights reserved.

Associated skeletons of a new middle Triassic ""Rauisuchia"" from Brazil

For more than 30 million years, in early Mesozoic Pangea, ""rauisuchian"" archosaurs were the apex predators in most terrestrial ecosystems, but their biology and evolutionary history remain poorly understood. We describe a new ""rauisuchian"" based on ten individuals found in a single locality from the Middle Triassic (Ladinian) Santa Maria Formation of southern Brazil. Nine articulated and associated skeletons were discovered, three of which have nearly complete skulls. Along with sedimentological and taphonomic data, this suggests that those highly successful predators exhibited some kind of intraspecific interaction. Other monotaxic assemblages of Triassic archosaurs are Late Triassic (Norian-Rhaetian) in age, approximately 10 million years younger than the material described here. Indeed, the studied assemblage may represent the earliest evidence of gregariousness among archosaurs, adding to our knowledge on the origin of a behavior pattern typical of extant taxa.

Integrability and exact solution of an electronic model with long range interactions

We present an electronic model with long range interactions. Through the quantum inverse scattering method, integrability of the model is established using a one-parameter family of typical irreducible representations of gl(211). The eigenvalues of the conserved operators are derived in terms of the Bethe ansatz, from which the energy eigenvalues of the Hamiltonian are obtained.

Characterization of a microcystin and detection of microcystin synthetase genes from a Brazilian isolate of Nostoc

A nostocalean nitrogen-fixing cyanobacterium isolated from an eutrophic freshwater reservoir located in Piracicaba, Sao Paulo, Brazil, was evaluated for the production of hepatotoxic cyclic heptapeptides, microcystins. Morphologically this new cyanobacterium strain appears closest to Nostoc, however, in the phylogenetic analysis of 165 rRNA gene it falls into a highly stable cluster distantly only related to the typical Nostoc cluster. Extracts of Nostoc sp. CENA88 cultured cells, investigated using ELISA assay, gave positive results and the microcystin profile revealed by ESI-Q-TOF/MS/MS analysis confirmed the production of [Dha(7)]MCYST-YR. Further, Nostoc sp. CENA88 genomic DNA was analyzed by PCR for sequences of mcyD, mcyE and mcyG genes of microcystin synthetase (mcy) cluster. The result revealed the presence of mcyD, mcyE and mcyG genes with similarities to those from mcy of Nostoc sp. strains 152 and IO-102-I and other cyanobacterial genera. The phylogenetic tree based on concatenated McyG, McyD and McyE amino acids clustered the sequences according to cyanobacterial genera, with exception of the Nostoc sp. CENA88 sequence, which was placed in a clade distantly related from other Nostoc strains, as previously observed also in the 165 rRNA phylogenetic analysis. The present study describes for the first time a Brazilian Nostoc microcystin producer and also the occurrence of demethyl MCYST-YR variant in this genus. The sequenced Nostoc genes involved in the microcystin synthesis can contribute to a better understanding of the toxigenicity and evolution of this cyanotoxin. (C) 2009 Elsevier Ltd. All rights reserved.

Purification and biochemical characterization of a novel alpha-glucosidase from Aspergillus niveus

An extracellular alpha-glucosidase produced by Aspergillus niveus was purified using DEAE-Fractogel ion-exchange chromatography and Sephacryl S-200 gel filtration. The purified protein migrated as a single band in 5% PAGE and 10% SDS-PAGE. The enzyme presented 29% of glycosylation, an isoelectric point of 6.8 and a molecular weight of 56 and 52 kDa as estimated by SDS-PAGE and Bio-Sil-Sec-400 gel filtration column, respectively. The enzyme showed typical alpha-glucosidase activity, hydrolyzing p-nitrophenyl alpha-d-glucopyranoside and presented an optimum temperature and pH of 65A degrees C and 6.0, respectively. In the absence of substrate the purified alpha-glucosidase was stable for 60 min at 60A degrees C, presenting t (50) of 90 min at 65A degrees C. Hydrolysis of polysaccharide substrates by alpha-glucosidase decreased in the order of glycogen, amylose, starch and amylopectin. Among malto-oligosaccharides the enzyme preferentially hydrolyzed malto-oligosaccharide (G10), maltopentaose, maltotetraose, maltotriose and maltose. Isomaltose, trehalose and beta-ciclodextrin were poor substrates, and sucrose and alpha-ciclodextrin were not hydrolyzed. After 2 h incubation, the products of starch hydrolysis measured by HPLC and thin layer chromatography showed only glucose. Mass spectrometry of tryptic peptides revealed peptide sequences similar to glucan 1,4-alpha-glucosidases from Aspergillus fumigatus, and Hypocrea jecorina. Analysis of the circular dichroism spectrum predicted an alpha-helical content of 31% and a beta-sheet content of 16%, which is in agreement with values derived from analysis of the crystal structure of the H. jecorina enzyme.

Quantum phase-space analysis of the pendular cavity

We perform a quantum-mechanical analysis of the pendular cavity, using the positive-P representation, showing that the quantum state of the moving mirror, a macroscopic object, has noticeable effects on the dynamics. This system has previously been proposed as a candidate for the quantum-limited measurement of small displacements of the mirror due to radiation pressure, for the production of states with entanglement between the mirror and the field, and even for superposition states of the mirror. However, when we treat the oscillating mirror quantum mechanically, we find that it always oscillates, has no stationary steady state, and exhibits uncertainties in position and momentum which are typically larger than the mean values. This means that previous linearized fluctuation analyses which have been used to predict these highly quantum states are of limited use. We find that the achievable accuracy in measurement is fat, worse than the standard quantum limit due to thermal noise, which, for typical experimental parameters, is overwhelming even at 2 mK

Impedance characteristics of the diamond/carbon fiber electrodes for electrical double-layer capacitor

The electrochemical performance of carbon fibers (CF) and boron-doped diamond electrodes grown on carbon fiber substrate (BDD/CF) was studied. CF substrates were obtained from polyacrylonitrile precursor heat treated at two different temperatures of 1000 and 2000 degrees C to produce the desirable CF carbon graphitization index. This graphitization process influenced the CF conductivity and its chemical surface, also analyzed from X-ray photoelectron spectroscopy measurements. These three-dimensional CF structures allowed a high incorporation of diamond films compared to other carbon substrates such as glass carbon or HOPG. The electrochemical responses, from these four classes of electrodes, were evaluated focusing their application as electrical double-layer capacitors using cyclic voltammetry and impedance measurements. Cyclic voltammetry results revealed that the electrode formed from BDD grown on CF-2000 presented a typical capacitor behavior with the best rectangular shape, compared to those electrodes of CF or BDD/CF-1000. Furthermore, the BDD/CF-2000 electrode presented the lowest impedance, associated to its significant capacitance value of 1940 mu F/cm(2) taking into account the BDD films. This behavior was attributed to the strong dependence between diamond coating texture and the CF graphitization temperature. The largest surface area of BDD/CF-2000 was promoted by its singular film growth mechanism associated to the substrate chemical surface. (c) 2008 Elsevier B.V. All rights reserved.

Morphological and electrochemical investigation of RuO(2)-Ta(2)O(5) oxide films prepared by the Pechini-Adams method

Preparation methods can profoundly affect the structural and electrochemical properties of electrocatalytic coatings. In this investigation, RuO(2)-Ta(2)O(5) thin films containing between 10 and 90 at.% Ru were prepared by the Pechini-Adams method. These coatings were electrochemically and physically characterized by cyclic voltammetry, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). The composition and morphology of the oxide were investigated before and after accelerated life tests (ALT) by EDX and SEM. SEM results indicate typical mud-flat-cracking morphology for the majority of the films. High resolution SEMs reveal that pure oxide phases exhibit nanoporosity while binary compositions display a very compact structure. EDX analyses reveal considerable amounts of Ru in the coating even after total deactivation. XRD indicated a rutile-type structure for RuO(2) and orthorhombic structure for Ta(2)O(5). XPS data demonstrate that the binding energy of Ta is affected by Ru addition in the thin films, but the binding energy of Ru is not likewise influenced by Ta. The stability of the electrodes was evaluated by ALT performed at 750 mA cm(-2) in 80 degrees C 0.5 mol dm(-3) H(2)SO(4). The performance of electrodes prepared by the Pechini-Adams method is 100% better than that of electrodes prepared by standard thermal decomposition.

A new clinical and molecular form of Unverricht-Lundborg disease localized by homozygosity mapping

Progressive myoclonus epilepsy (PME) has a number of causes, of which Unverricht-Lundborg disease (ULD) is the most common. ULD has previously been mapped to a locus on chromosome 21 (EPM1). Subsequently, mutations in the cystatin B gene have been found in most cases. In the present work we identified an inbred Arab family with a clinical pattern compatible with ULD, but mutations in the cystatin B gene were absent. We sought to characterize the clinical and molecular features of the disorder. The family was studied by multiple field trips to their town to clarify details of the complex consanguineous relationships and to personally examine the family. DNA was collected for subsequent molecular analyses from 21 individuals. A genome-wide screen was performed using 811 microsatellite markers. Homozygosity mapping was used to identify loci of interest. There were eight affected individuals. Clinical onset was at 7.3 +/- 1.5 years with myoclonic or tonic-clonic seizures. All had myoclonus that progressed in severity over time and seven had tonic-clonic seizures. Ataxia, in addition to myoclonus, occurred in all. Detailed cognitive assessment was not possible, but there was no significant progressive dementia. There was intrafamily variation in severity; three required wheelchairs in adult life; the others could walk unaided. MRI, muscle and skin biopsies on one individual were unremarkable. We mapped the family to a 15-megabase region at the pericentromeric region of chromosome 12 with a maximum lod score of 6.32. Although the phenotype of individual subjects was typical of ULD, the mean age of onset (7.3 years versus 11 years for ULD) was younger. The locus on chromosome 12 does not contain genes for any other form of PME, nor does it have genes known to be related to cystatin B. This represents a new form of PME and we have designated the locus as EPM1B.

Jacobsen catalyst immobilized on chitosan membrane as interface catalyst in organic/aqueous system for alkene oxidation

The Jacobsen catalyst, Mn(salen), was immobilized in chitosan membrane. The obtained Mn(salen)-Chit was characterized by thermogravimetric analysis (TC), differential thermal analysis (DTA), differential scanning calorimetry (DSC), infrared spectroscopy (FT-IR), degree of N-acetylation by (1)H NMR, and UV-vis spectroscopy. The UV-vis absorption spectrum of the encapsulated catalyst displayed the typical bands of the Jacobsen catalyst, and the FT-IR presented an absorption band characteristic of the imines present in the Jacobsen catalyst. The chitosan membranes were available, in a biphasic system, as a catalytic barrier between two different phases: an organic substrate phase (cyclooctene or styrene) and an aqueous solution of either m-CPBA, t-BuOOH or H(2)O(2), and dismissing the need for phase transfer agents and leading to better product yields compared with the catalyst in homogeneous medium. This new catalyst did not leach from the support and was reused many times, leading to high turnover frequencies. (C) 2009 Elsevier B.V. All rights reserved.

QUADRANT-SEARCHING: A NEW TECHNIQUE TO REDUCE THE SEARCH SPACE OF THE INVERSE PROBLEM OF EIT USING BEM TO THE DIRECT PROBLEM

The image reconstruction using the EIT (Electrical Impedance Tomography) technique is a nonlinear and ill-posed inverse problem which demands a powerful direct or iterative method. A typical approach for solving the problem is to minimize an error functional using an iterative method. In this case, an initial solution close enough to the global minimum is mandatory to ensure the convergence to the correct minimum in an appropriate time interval. The aim of this paper is to present a new, simple and low cost technique (quadrant-searching) to reduce the search space and consequently to obtain an initial solution of the inverse problem of EIT. This technique calculates the error functional for four different contrast distributions placing a large prospective inclusion in the four quadrants of the domain. Comparing the four values of the error functional it is possible to get conclusions about the internal electric contrast. For this purpose, initially we performed tests to assess the accuracy of the BEM (Boundary Element Method) when applied to the direct problem of the EIT and to verify the behavior of error functional surface in the search space. Finally, numerical tests have been performed to verify the new technique.

Interaction of adrenocorticotropin peptides with microheterogeneous systems - A fluorescence study

Adrenocorticotropin (ACM) and alpha-melanocyte stimulating hormone (alpha-MSH) are peptides which present many physiological effects related to pigmentation, motor and sexual behavior, learning and memory, analgesia, anti-inflammatory and antipyretic processes. The 13 amino acid residues of alpha-MSH are the same initial sequence of ACM and due to the presence of a tryptophan residue in position 9 of the peptide chain, fluorescence techniques could be used to investigate the conformational properties of the hormones in different environments and the mechanisms of interaction with biomimetic systems like sodium dodecyl sulphate (SDS) micelles, sodium dodecyl sulphate-poly(ethylene oxide) (SDS-PEO) aggregates and neutral polymeric micelles. In buffer solution, fluorescence parameters were typical of peptides containing tryptophan exposed to the aqueous medium and upon addition of surfactant and polymer molecules, the gradual change of those parameters demonstrated the interaction of the peptides with the microheterogeneous systems. From time-resolved experiments it was shown that the interaction proceeded with conformational changes in both peptides, and further information was obtained from quenching of Trp fluorescence by a family of N-alkylpyridinium ions, which possess affinity to the microheterogeneous systems dependent on the length of the alkyl chain. The quenching of Trp fluorescence was enhanced in the presence of charged micelles, compared to the buffer solution and the accessibility of the fluorophore to the quencher was dependent on the peptide and the alkylpyridinium: in ACTH(1-21) highest collisional constants were obtained using ethylpyridinium as quencher, indicating a location of the residue in the surface of the micelle, while in alpha-MSH the best quencher was hexylpyridinium, indicating insertion of the residue into the non-polar region of the micelles. The results had shown that the interaction between the peptides and the biomimetic systems where driven by combined electrostatic and hydrophobic effects: in ACTH(1-24) the electrostatic interaction between highly positively charged C-terminal and negatively charged surface of micelles; and aggregates predominates over hydrophobic interactions involving residues in the central region of the peptide; in alpha-MSH, which presents one residual positive charge, the hydrophobic interactions are relevant to position the Trp residue in the non-polar region of the microheterogeneous systems. (C) 2008 Elsevier B.V. All rights reserved.

Sexual maturity and egg production in an unexploited population of the red squat lobster Pleuroncodes monodon (Decapoda, Galatheidae) from Central America

The squat lobster Pleuroncodes monodon is one of the most common and abundant galatheid species in the deepwater fishery of Pacific coast of America. In contrast with Peru and Chile, the red squat lobster is not commercially exploited in Costa Rica. Here we estimated the size of sexual maturity and analysed egg production in P. monodon from the Pacific of Costa Rica; the results might be important for an adequate management strategy when initiating a sustainable fishery of this resource in Costa Rica. Analyses of allometric growth revealed that females and males reached their morphological sexual maturity at 26.9 and 30.4 mm CL. respectively. The percentage of immature females captured in the present study (54%) suggests that almost half of females are able to reproduce before they are caught. Egg production was positively correlated with body size; females that measured between 24.1 and 29.0 mm CL contributed roughly 90% to the offspring production of the population. Females from Costa Rica had a considerably lower average egg volume (0.039 mm(3)) and higher fecundity (9810) than females from Chile. In comparison to other American galatheids P. monodon from Costa Rica produces numerous but small eggs, a typical strategy of species with a prolonged larval development. An analysis between our results and information published about P. monodon from Chile also revealed differences in the size-frequency distribution shape of both populations. The non-exploited character of the Costa Rican P. monodon population and a latitudinal (temperature-related) cline in body size might be associated with these differences. (C) 2010 Elsevier B.V. All rights reserved.

Interfacial interactions and structure of organic-inorganic nanohybrids

Understanding the interfacial interactions and structure is important to better design and application of organic-inorganic nanohybrids. This paper presents our recent molecular dynamic studies on organoclays and polymer nanocomposites, including the layering behavior of organoclays, structural and dynamic properties of dioctadecyldimethyl ammoniums in organoclays, and interfacial interactions and structure of polyurethane nanocomposites. The results demonstrate that the layering behaviors of organoclays are closely related to the chain length of quaternary alkyl ammoniums and cation exchangeable capacity of clays. In addition to typical layered structures such as monolayer, bilayer and pseudo-trilayer, a pseudo-quadrilayer structure was also observed in organoclays modified with dioctadecyldimethyl ammoniums (DODDMA). In such a structure, alkyl chains do not lie flat within a single layer but interlace, and also jump to the next layer or even the next nearest layer. Moreover, the diffusion constants of nitrogen and methylene atoms increase with the temperature and methelene towards the tail groups. For polyurethane nanocomposite, the van der Waals interaction between apolar alkyl chains and soft segments of polyurethane predominates the interactions between organoclay and polyurethane. Different from most bulk polyurethane systems, there is no distinct phase-separated structure for the polyurethane.

Luminescent Langmuir-Blodgett film of a new amphiphilic Eu(3+) beta-diketonate

This work reports on the synthesis and characterization of the ligand 3-hexadecylpentane-2,4-drone (Hhdacac) and its Eu(3+) complexes Eu(hdacac)(6) center dot 2H(2)O, Eu(hdacac)(6) center dot phen and Eu(hdacac)(6) center dot tta, where phen and tta denote 1,10-phenanthroline and thenoyltrifluoroacetone, respectively. These new compounds present long carbon chains and their expected miscibility into non-polar ambients is confirmed by the emission spectra of Eu(hdacac)6 center dot tta in hexane. Moreover, the amphiphilic properties of Eu(hdacac)6 complexes allow the obtainment of thin luminescent films by the Langmuir-Blodgett technique. In both cases (solids and films), the typical antenna effect of beta-diketonates is observed. The alluring characteristics of these compounds raise great interest in many fields of Materials Science, like photo- and electro-luminescent materials (mainly thin ""organic"" films), metal catalysts or probes in non-polar solutions, and Langmuir-Blodgett films of several compositions. For the characterization of these products, nuclear magnetic resonance spectroscopy ((1)H NMR), thermogravimetric analysis, elementary analyses (C, H), scanning electron microscopy (energy dispersive X-ray spectroscopy), absorption (UV-vis/FT-IR) and photoluminescence spectroscopies were used. (c) 2008 Elsevier B.V. All rights reserved.