Effect of the processing conditions and the addition of trans-polyoctenylene rubber on the properties of natural rubber/styrene-butadiene rubber blends

In this study, the influence of the processing conditions and the addition of trans-polyoctenylene rubber (TOR) on Mooney viscosity, tensile properties, hardness, tearing resistance, and resilience of natural rubber/styrene-butadiene rubber blends was investigated. The results obtained are explained in light of dynamic mechanical and morphological analyses. Increasing processing time produced a finer blend morphology, which resulted in an improvement in the mechanical properties. The addition of TOR involved an increase in hardness, a decrease in tear resistance, and no effect on the resilience. It resulted in a large decrease in the Mooney viscosity and a slight decrease in the tensile properties if the components of the compounds were not properly mixed. The results indicate that TOR acted more as a plasticizer than a compatibilizer. (c) 2008 Wiley Periodicals, Inc.

Effects of the herbicides acetochlor and metolachlor on antioxidant enzymes in soil bacteria

The aim of this study was to investigate the antioxidant responses of three bacteria (SD1. KD and K9) isolated from soil previously treated with the herbicides metolachlor and acetochlor. By 165 rRNA gene sequencing, we determined that SD1 is phylogenetically related to Enterobacter asburiae, while KD and K9 have divergent genomes that more closely resemble that of Enterobacter amnigenus. Decreased levels of lipid peroxidation were observed in SD1 and KD following treatment with 34 mM metolachlor or 62 mM acetochlor, respectively, indicating that both bacteria were able to adapt to an increase in ROS production. In the presence of 34 mM metolachlor or 62 mM acetochlor, all bacterial isolates exhibited increases in total catalase (CAT) activity (81% for SDI, 53% for KD and 59% for K9), whereas total SOD activity (assessed based on the profile and intensity of the bands) was slightly reduced when the bacteria were exposed to high concentrations of the herbicides (340 mM metolachlor or 620 mM acetochlor). This effect was due to a specific reduction in SOD IV (K9 and KD isolates) by 45% and 90%, respectively, and SOD V (SD1 isolate) isoenzymes by 60%. The most striking result was obtained in the SD1 isolate, where two novel isoenzymes of glutathione reductase (GR) that responded specifically to metolachlor were identified. In addition, acetochlor was shown to induce the expression of a new 57 kDa protein band in the K9 and KD isolates. The bacteria isolated from the herbicide-contaminated soil exhibited an efficient antioxidant system response at herbicide concentrations of up to 34 mM metolachlor or 62 mM acetochlor. These data suggest a mechanism for tolerance that may include the control of an imbalance in ROS production versus scavenging. The data suggest that specific isoenzymes of CAT and GR could be involved in this herbicide tolerance mechanism. (C) 2011 Elsevier Ltd. All rights reserved.

Allele-Specific Expression of the MAOA Gene and X Chromosome Inactivation in In Vitro Produced Bovine Embryos

During embryogenesis, one of the two X chromosomes is inactivated in embryos. The production of embryos in vitro may affect epigenetic mechanisms that could alter the expression of genes related to embryo development and X chromosome inactivation (XCI). The aim of this study was to understand XCI during in vitro, pre-implantation bovine embryo development by characterizing the allele-specific expression pattern of the X chromosome-linked gene, monoamine oxidase A (MAOA). Two pools of ten embryos, comprised of the 4-, 8- to 16-cell, morula, blastocyst, and expanded blastocyst stages, were collected. Total RNA from embryos was isolated, and the RT-PCR-RFLP technique was used to observe expression of the MAOA gene. The DNA amplicons were also sequenced using the dideoxy sequencing method. MAOA mRNA was detected, and allele-specific expression was identified in each pool of embryos. We showed the presence of both the maternal and paternal alleles in the 4-, 8-to 16-cell, blastocyst and expanded blastocyst embryos, but only the maternal allele was present in the morula stage. Therefore, we can affirm that the paternal X chromosome is totally inactivated at the morula stage and reactivated at the blastocyst stage. To our knowledge, this is the first report of allele-specific expression of an X-linked gene that is subject to XCI in in vitro bovine embryos from the 4-cell to expanded blastocyst stages. We have established a pattern of XCI in our in vitro embryo production system that can be useful as a marker to assist the development of new protocols for in vitro embryo production. Mol. Reprod. Dev. MoL Reprod. Dev. 77: 615-621, 2010. (C) 2010 Wiley-Liss, Inc.

EVALUATION OF THE INFLUENCE OF THE PROTEINIC QUALITY OF THE GENETICALLY MODIFIED AND ORGANIC SOY BEANS IN THE GROWTH OF TWO GENERATIONS OF RATS WISTAR

Feijo, T.S., Cardozo, SX, Daleprane, J.B., Sabaa Srur, A.U.O. & Boaventura, G.T. [Evaluation of the influence of the proteinic quality of the genetically modified and organic soy beans in the growth of two generations of rats Wistar.] Avaliacao da influencia da qualidade proteica da soja geneticamente modificada e organica no crescimento de duas geracoes de ratos Wistar. Revista Brasileira de Medicina Veterinaria, 31(3):139-144, 2009. Programa de Pos-Graduacao em Patologia, Hospital Universitario Antonio Pedro. Centro de Ciencias Medicas, Universidade Federal Fluminense. Rua Marques do Parana, 303, Niteroi, RJ 24030-210, Brasil. E-mail: sergian@ufnj.br Sixty four Wistar rats, male of two consecutive generations determined as F(0) and F(1) were used to study the cumulative effect of two variety soy beans, cultivated with organic seasoning and genetically modified, The animals of each generation were divided into three groups of eight rats each fed on diets consisted of organic soy, soy genetically modified and casein respectively. All the animals received water and the diet ad libitum for period of 28 days. Where the diet consumption and the animals weight were evaluated. After statistic analysis of the results no expressive differences were observed on diet consumption, weight variation, protein efficient ratio and food efficiency ratio on same group of animals in the different generations. On the other hand, significant difference was found on final proteinic retention on animal descendants of the same groups; however of different generations. With this, the supplementation of organic soy with L-cistin provided better avail of this protein in relation to the protein of the soy genetically modified. However, this supplementation did not reveal efficiency in keeping the proteinic employment from one generation to another one, since soy varieties presented better performance on F(0) generation when compared with F(1).

Retention of the Enzymatic Activity and Product Properties During Spray Drying of Pineapple Stem Extract in Presence of Maltodextrin

The aim of this work was to investigate the effects of drying parameters on the retention of the enzymatic activity and on the physical properties of spray-dried pineapple stem extract. A Box and Behnken experimental design was used to investigate the effects of the processing parameters on the product properties. The parameters studied were the inlet temperature of drying gas (Tgi), the feed flow rate of the pineapple extract relative to evaporative capacity of the system (Ws /Wmax), and the concentration of maltodextrin added to the extract (MD). Significant effects of the processing parameters on the retention of the proteolytic activity of the powdered extract were observed. High processing temperatures lead to a product with a smaller moisture content, particle size, and lower agglomerating tendency. A product with insignificant losses of the proteolytic activity ( 10%) and low moisture content (less than 6.5%) is obtained at selected conditions.

Comparison of the chemical composition of the essential oil and the water soluble oil of Baccharis dracunculifolia DC. (Asteraceae)

This study aimed to evaluate the chemical composition of Baccharis dracunculifolia essential oil and the water soluble oil obtained by steam distillation that were analyzed by GC and GUMS. in the first hour of distillation, B. dracunculifolia aerial parts yielded 0.08% oil and in the second hour, 0.27%. The oil recovered from the distillate water yielded 0.18 g/L in the first hour and 0.44 g/L in the second hour of distillation. The main volatile compounds identified in the distillate water were aromatic compounds and sesquiterpene alcohols.

Seasonal Variation of the (E)-Nerolidol and Other Volatile Compounds Within Ten Different Cultivated Populations of Baccharis dracunculifolia DC (Asteraceae)

Initially, the seeds of Baccharis dracunculifolia were collected from populations of 10 different regions, and the cultivation experiment was carried out in an experimental area of 1,800 m(2) by cultivating 100 individuals of each population. The essential oil analyses were performed on both GC-FID and GUMS, which allowed the identification of 14 compounds. The oil yield varied from 0.31% to 0.70% among populations and season. The major oxygenated sesquiterpenes in the cultivated experiment were (E)-nerolidol (32%) and spathulenol (17%). The mean concentration in the plant of (E)-nerolidol was five times higher in March (136.53 mg/100 g of plant) than it was in July (25.03 mg/100 g of plant). The mean concentration of spathulenol increased about three fold from July (16.25 mg/100 g of plant) to April (47.50 mg/100 g of plant).

Cytotoxic and mutagenic evaluation of extracts from plant species of the Miconia genus and their influence on doxorubicin-induced mutagenicity: An in vitro analysis

The Miconia genus, a plant widely used for medicine, occurs in tropical America and its extracts and isolated compounds have demonstrated antibiotic, antitumoral, analgesic and antimalarial activities. However, no study concerning its genotoxicity has been conducted and it is necessary to determine its potential mutagenic effects to develop products and chemicals from these extracts. This study assessed the cytotoxicity, mutagenicity and the protective effects of methanolic extracts from Miconia species on Chinese hamster lung fibroblast cell cultures (V79). The cytotoxicity was evaluated using a clonogenic assay. Cultures exposed to the extract of Miconia albicans up to a concentration of 30 mu g/mL, M. cabucu up to 40 mu g/mL, M. albicans up to 40 mu g/mL and M. stenostachya up to 60 mu g/mL exhibited a cytotoxic effect on the cells. The clonogenic assay used three non-cytotoxic concentrations (5, 10 and 20 mu g/mL) to evaluate mutagenicity and antimutagenicity of the extracts. Cultures were treated with these three extract concentrations (mutagenicity test) or the extract associated with doxorubicin (DXR) (antimutagenicity test) in three protocols (pre-, simultaneous and post-treatments). Distilled water and DXR were used as negative and positive controls, respectively. In the micronucleus (MN) test, a significant reduction was observed in MN frequency in cultures treated with DXR and extracts compared to those receiving only DXR; a significant reduction was also observed for the presence of mutagenicity in all treatments. This study confirmed the safe use of Miconia extracts at the concentrations tested and reinforced the therapeutic properties previously described for Miconia species by showing their protective effects on doxorubicin-induced mutagenicity. (C) 2010 Elsevier GmbH. All rights reserved.

Systemic Model for Diagnosis of the Micro, Small and Medium Enterprises from Two Cities from the Countryside of the State of So Paulo in Brazil

This article presents a proposal of a systemic model composed for the micro and small companies (MSE) of the region of Ribeiro Preto and the agents which influenced their environment. The proposed model was based on Stafford Beer`s (Diagnosing the system for organizations. Chichester, Wiley, 1985) systemic methodologies VSM (Viable System Model) and on Werner Ulrich`s (1983) CSH (Critical Systems Heuristics). The VSM is a model for the diagnosis of the structure of an organization and of its flows of information through the application of the cybernetics concepts (Narvarte, In El Modelo del Sistema Viable-MSV: experiencias de su aplicacin en Chile. Proyecto Cerebro Colectivo del IAS, Santiago, 2001). On the other hand, CSH focus on the context of the social group applied to the systemic vision as a counterpoint to the organizational management view considered by the VSM. MSE of Ribeiro Preto and Sertozinho had been analyzed as organizations inserted in systems that relate and integrate with other systems concerning the public administration, entities of representation and promotion agencies. The research questions: which are the bonds of interaction among the subsystems in this process and who are the agents involved? The systemic approach not only diagnosed a social group, formed by MSE of Ribeiro Preto and Sertozinho, public authorities and support entities, but could also delineate answers that aimed the clarification of obscure questions generating financial assistance to the formularization of efficient actions for the development of this system.

A costs structure analysis of the Brazilian sugar and ethanol companies

The Brazil consolidated itself as the largest world producer of sugarcane, sugar and ethanol. The creation of the Programa Nacional do Alcool - PROALCOOL and the growing use of cars with flexible motors were some of the factors that helped to motivate still more the production. Evolutions in the agricultural and industrial research did the Brazilian competitiveness in sugar and ethanol globally elevated, what is evidenced when comparing the amount produced at the country and the production costs, which turned a big one differential. Therefore, the administration of costs is of great relevance to the sugar and ethanol companies, for representing a significant rationalization in the production processes, with economy of resources and the reach of better earnings, besides reducing the operational risk pertinent at the fixed costs of production. Thus, the present work has for objective to analyze the costs structure of sugar and ethanol companies of the Center-south area of the country through an empiric-analytical study based in methodologies and concepts extracted of the costs accounting. It is verified that great part of the costs and operational expenses have variable behavior, a positive factor for the sector reducing the operational risk of the activity. The main restraint of this study is the sample of five years and 10% of the number of plants in Brazil that although they represent 30% of the national production, don`t allow the generalization of the model.

Anticonvulsant profile of the alkaloids (+)-erythravine and (+)-11-alpha-hydroxy-erythravine isolated from the flowers of Erythrina mulungu Mart ex Benth (Leguminosae-Papilionaceae)

Neural mechanisms underlying the onset and maintenance of epileptic seizures involve alterations in inhibitory and/or excitatory neurotransmitter pathways. Thus, the prospecting of novel molecules from natural products that target both inhibition and excitation systems has deserved interest in the rational design of new anticonvulsants. We isolated the alkaloids (+)-erythravine and ( +)-11-alpha-hydroxyerythravine from the flowers of Erythrina mulungu and evaluated the action of these compounds against chemically induced seizures in rats. Our results showed that the administration of different doses of (+)-erythravine inhibited seizures evoked by bicuculline, pentylenetetrazole, and kainic acid at maximum of 80, 100, and 100%, respectively, whereas different doses of (+)-11-alpha-hydroxy-erythravine inhibited seizures at a maximum of 100% when induced by bicuculline, NMDA, and kainic acid, and, to a lesser extent, PTZ (60%). The analysis of mean latency to seizure onset of nonprotected animals, for specific doses of alkaloids, showed that (+)-erythravine increased latencies to seizures induced by bicuculline. Although (+)-erythravine exhibited very weak anticonvulsant action against seizures induced by NMDA, this alkaloid increased the latency in this assay. The increase in latency to onset of seizures promoted by (+)-11-alpha-hydroxy-erythravine reached a maximum of threefold in the bicuculline test. All animals were protected against death when treated with different doses of (+)-11-alpha-hydroxy-erythravine in the tests using the four chemical convulsants. Identical results were obtained when using (+)-erythravine in the tests of bicuculline, NMDA, and VIZ, and, to a lesser extent, kainic acid. Therefore, these data validate the anticonvulsant properties of the tested alkaloids, which is of relevance in consideration of the ethnopharmacological/biotechnological potential of E. mulungu. (C) 2010 Elsevier Inc. All rights reserved.

Niobium to alcohol mol ratio control of the concurring esterification and etherification reactions promoted by NbCl5 and Al2O3 catalysts under microwave irradiation

Alcohols and acids can be switched to produce ethers or esters by varying the alcohol to catalyst mol ratio, in a new etherification and esterification method using NbCl5/Al2O3 catalyst under ""solvent free"" conditions and promoted by MW (microwave) irradiation. A ""two sites"" mechanism for the reaction is proposed, in an attempt to clarify the tendency of the catalyst to be dependent on the alcohol alone during the esterification process. (c) 2008 Elsevier B.V. All rights reserved.

Composition and diversity of Ephemeroptera (Insecta) nymph communities in the middle section of the Jacui River and some tributaries, southern Brazil

The taxonomic composition and diversity of assemblages of Ephemeroptera nymphs of four lotic environments in the central region of State of Rio Grande do Sul, a subtropical area in southern Brazil, were evaluated. Samplings were done monthly, with a Surber sampler, from June 2001 to May 2002, in the Jacui River and three of its tributaries. The total number of nymphs collected in the four sampling sites was 11,007 in five families and 19 genera, of these, 11 are new records for the State. The highest diversity occurred in Point 4 (H` = 2.41) and the lowest in Point 2 (H` = 1.69). Point 4 had the highest environmental stability, conservation of the riparian vegetation and the lowest anthropic impact, while Point 2 presented a large environmental simplification due to a direct anthropic influence ( e. g. domestic sewerage, trampling by cattle). The diversity of nymphs observed in the total area is high, compared to the estimated maximum theoretical diversity; a result of the high evenness and richness recorded. Rarefaction curves, calculated for a sample of 1,018 specimens, showed a similar expectation of richness for the four sampling sites. This result seems to be associated with the overall environmental homogeneity of the region caused by long-term alterations ( land use and deforestation). In summary, higher diversity of Ephemeroptera nymph assemblages seems to be associated with habitat complexity, a good vegetation cover and a lower anthropic influence.

Phylogeny of the Limnophilinae (Limoniidae) and early evolution of the Tipulomorpha (Diptera)

Tipulomorpha (craneflies) comprise one of the largest subgroups of Diptera, but its phylogeny at different levels has been poorly explored. This study presents the most comprehensive cladistic analysis of the group ever made, with emphasis on the genera and subgenera of the subfamily Limnophilinae (Limoniidae), assumed to include some of the earliest lineages of Tipulomorpha sensu stricto and therefore important for the understanding of the early patterns in the evolution of the craneflies. Eighty-eight characters of the male imago were scored for 104 exemplar species. The most parsimonious trees were searched using implied weighting, in the framework of a sensitivity analysis with different values of k (2 to 6). The dataset based on the characters of adult male morphology showed high levels of homoplasy and yielded very incongruent and unstable phylogenetic results, which are very sensitive to changes in analytical parameters. In the preferred and most parsimonious phylogenetic hypothesis, the Pediciidae is the sister-group of all other Tipulomorpha sensu stricto. The results indicate the paraphyly of the Limoniidae with respect to the Cylindrotomidae and Tipulidae, which are considered sister-groups. The Limoniidae subfamilies Limnophilinae, Limoniinae and Chioneinae are considered non-monophyletic. The study allowed a reconstruction of the possible ground plan condition of selected features of the adult male morphology of craneflies. The genera/subgenera Epiphragma (Epiphragma), Acantholimnophila, Shannonomyia, Limnophila (Arctolimnophila), Eloeophila, Conosia, Polymera, Polymera (Polymerodes), Prionolabis, Eutonia, Phylidorea (Phylidorea), Metalimnophila, Gynoplistia (Cerozodia), Gynoplistia (Dirhipis), Nothophila, Pseudolimnophila (Pseudolimnophila), Pilaria and Ulomorpha are considered monophyletic, but in general are defined by combinations of very homoplastic character states. Two Temperate Gondwanan clades, (Tonnoirella + (Edwardsomyia + (Tinemyia + (Rhamphophila + (Nothophila))))) and ((Notholimnophila + Bergrothomyia) + (Mesolimnophila + (Chilelimnophila + Ctenolimnophila))) are recovered. The genera Limnophila, Neolimnomyia, Gynoplistia (sensu lato) and Hexatoma (sensu lato) are considered non-monophyletic. The systematic position and some morphological characters of `problematic` taxa, such as Dactylolabis, Elephantomyia, Helius and Atarba are discussed on the light of the proposed phylogeny and the analysis of the characters. Character states are richly illustrated. A detailed study of the morphology of the male genitalia is made, and several genera and species have the morphology of the male genitalia illustrated for the first time.

Mutations of the thyroglobulin gene and its relevance to thyroid disorders

Purpose of review To perform an update review on thyroglobulin gene mutations associated with congenital hypothyroidism, thyroid cancer, and autoimmunity. Recent findings Forty-two thyroglobulin mutations have been identified in dyshormonogenetic congenital hypothyroidism. Clinical and laboratory criteria defining defective thyroglobulin synthesis are mostly related to thyroglobulin mutations, generally caused by intracellular thyroglobulin transport defects to the colloid rather than defects in thyroid hormones synthesis. Some mutated thyroglobulin may escape the rigorous chaperone control and reach the colloid, allowing a wide phenotypic spectrum that includes euthyroidism in an adequate iodine environment. In some patients, continuous levothyroxine treatment does not reduce elevated serum thyroid-stimulating hormone (TSH) levels that may lead to goiter development. Prenatally, inactive mutant thyroglobulin will not be able to synthesize thyroid hormones and may increase pituitary thyrotroph threshold for thyroid hormone feedback. Congenital goiter is a risk factor for thyroid cancer and some thyroglobulin variants may confer susceptibility to thyroid autoimmunity. Summary Advances in the understanding of thyroglobulin genetic defects and its severity should allow researchers to perform adequate molecular diagnosis, genetic counseling, and intrauterine treatment to prevent subtle deficits in central nervous system development. This knowledge should improve the understanding of physiological functions of the thyroid and influence of nutritional iodine.