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It was recently discovered that exposure to small concentrations of the essential oils of sweet fennel (Foeniculum vulgare Mill) or pignut [Hyptis suaveolens (L.) Poit] can be used to control aphids. What is not known is whether these oils also influence honeybee behavior. Experiments using both harnessed and free-flying foragers at concentrations used to control aphids showed that bees readily associated the odors with a reward, discriminated between them, and were not repelled. Honeybees, however, would not consume the oils when mixed with sucrose to create an unconditioned stimulus. An experiment in which harnessed bees consumed various concentrations showed that concentrations greater than 50% were detrimental. The experiments reported here provide further evidence supporting the use of conditioning techniques to evaluate the use of essential oils on honey bee behavior.

Mesoporous SBA-15 impregnated with tetrapropylammonium hydroxide and sodium aluminate was crystallized in glycerol containing different amounts of water (0 – 40 weight %). Under these conditions crystallization in glycerol containing at least 30 weight % of water leads to ZSM-5 as discrete particles. No formation of ZSM-5 or ZSM-5 precursors was observed after secondary crystallization of SBA-15 in glycerol with water contents of 15 weight % or lower.

Micro/mesostructured ZSM-5/SBA-15 composites were prepared by secondary crystallisation of SBA-15 impregnated with a solution of tetrapropylammonium hydroxide and sodium aluminate. The samples were characterised by X-ray diffraction (XRD), nitrogen sorption, infrared spectroscopy (FTIR) and scanning electronic microscopy (SEM). XRD and nitrogen sorption confirmed the partial preservation of the mesoporous structure and the formation of ZSM-5. Formation of ZSM-5 structural units in still X-ray amorphous material was detected by FTIR, which further indicates the incorporation of aluminium into the ZSM-5 structure. However, SEM micrographs showed the mesoporous SBA-15 and the microporous ZSM-5 as segregate particles evidencing that direct transformation of the SBA-15 pore walls into microporous ZSM-15 is unlikely. An enhanced activity in the isomerization of m-xylene on the recrystallised samples was observed.

Plants have been related to our lives, being used as medicine, regardless of scientific evidence of side effects. This work analyses the toxicological effects of Chrysobalanus icaco L. aqueous extract, used in different pathologies. It was studied through: (i) alteration of plasmid pUC 9.1 topology; (ii) survival of bacterial strains submitted, or not, to previous treatment with SnCl2; (iii) transformation efficiency of E. coli strain by the treatment with the plasmid pUC 9.1. In (i), the treatment of the plasmid resulted in DNA single-strand breaks (SSB). A decrease of the lethal effect induced by SnCl2 in presence of the extract was found, while no C. icaco bacterial survival reduction was observed. The transformation efficiency of the plasmid was also reduced. Results suggest that the extract could present a potential genotoxic effect, as demonstrated either by the induction of SSB in plasmid or in transformation efficiency experiments. Finally, it presents an antioxidant action.

Senna (Cassia angustifolia Vahl.) is widely used as laxative, but data from Ames test and animal and/or human studies with this agent have shown a mutagenic and carcinogenic potentiality. Using thee experimental models (bacterial inactivation test; bacterail mutagenisis assay-Mutoxitest; and growth Inhibition test, we investigated the toxicity of senna. Our data suggest an absence of mutagenic and citotoxic potentiality of senna. Sena (Cassia angustifolia Vahl.) é uma espécie amplamente empregada como laxativa, mas dados mutagênicos realizados com teste de Ames e estudos animais e/ou em humanos com esse agente tem mostrado uma potencialidade mutagênica e carcinogênica. Usando três diferentes testes (inativação de bactérias; ensaio de mutagênese em bactérias - Mutoxitest; teste de inibição de crescimento), foi investigada a toxidade dessa planta. Nossos dados sugerem uma ausência da potencialidade mutagênica e citotoxicidade de sena.

The recent discovery of chaotic synchronization has spawned a flurry of activity in applying chaos to communications. These efforts have sought to explore the potential capabilities/benefits of the three basic elements in a chaos-based communications system: the chaotic carrier, the synchronization process, and the carrier modulation. The heart of these systems is the chaos generator that must be configured to produce the generalized carrier. Several generator implementations have been developed, including low-frequency analog and digital circuits, and high frequency analog phase-locked loops and negative-resistance based oscillators. This paper surveys efforts to push chaos generation from baseband to a wideband high-frequency regime, forming the basis for a broadband microwave chaos-based communications system. Several key circuit implementation issues involving this frequency migration are identified and discussed. Accomplishment highlights are presented, including the invention of a novel wideband high-frequency chaotic oscillator design approach.

Stannous ion has been used in different sectors of human interest, such as in food industry and in health sciences. Much is known about stannous chloride (SnCl(2)) toxicity, although, there is no general agreement regarding its genotoxicity. Cymbopogon citratus, Maytenus ilicifolia and Baccharis genistelloides extracts have been used in popular medicine. We evaluated the influence of these crude extracts on the survival of the Escherichia coli wild type (AB 1157) strain submitted to SnCl(2) treatment. Reactive oxygen species (ROS) can be generated by a Fenton like reaction induced by SnCl(2). E. coli culture was treated simultaneously with SnCl(2) and a specific extract. Our results showed a reduction of the SnCl(2) effect on the survival of the cultures in presence of the crude extracts. The extract of M. ilicifolia showed the highest level of protection action against the SnCl(2) effect in comparison with the other extracts. This protector effect could due to the redox properties of these crude extracts. The compounds in the crude extracts could (i) chelate stannous ions, protecting them against the oxidation and avoiding the generation of ROS, (ii) be a scavenger of the ROS generated by the SnCl(2) oxidation and/or (iii) have oxidant compounds that could oxidise the stannous ions, abolishing or reducing the SnCl(2) effect.

The influence of drugs on the labeling of red blood cells and plasma proteins with 99mTc has been reported. Any drug, which alters the labeling of the tracer, could be expected to modify the disposition of the radiopharmaceuticals. Red blood cells (RBC) labeled with technetium-99m (99mTc) are used for several evaluations in nuclear medicine. We have evaluated the effect of Thuya occidentalis, Peumus boldus and Nicotiana tabacum (tobacco) extracts on the labeling of RBC and plasma and cellular proteins with 99mTc. Blood was incubated with the drugs. Stannous chloride (SnCl2) solutions and 99mTc were added. Plasma (P) and blood cells (BC) were separated. The percentage of radioactivity (%ATI) bound to P and BC was determined. The %ATI on the plasma and cellular proteins was also evaluated by precipitation of P and BC samples with trichloroacetic acid (TCA) and isolation of soluble (SF) and insoluble (IF) fractions. The analysis of the results shows that there is a decrease in %ATI (from 97.64 to 75.89 percent) in BC with Thuya occidentalis extract. The labeling of RBC and plasma proteins can be decreased in presence of tobacco. This can be due either a direct or indirect effect (reactive oxygen species) of tobacco. The analysis of radioactivity in samples of P and BC isolated from samples of whole blood treated with Peumus boldus showed a rapid uptake of the radioactivity by blood cells in the presence of the Peumus boldus, whereas there was a slight decrease in the amount of 99mTc radioactivity in the TCA-insoluble fraction of plasma. This study shows that extracts of some medicinal plants can affect the radiolabeling of red blood cells with 99mTc using an in vitro technique.

Peumus boldus extract has been used in popular medicine in the treatment of biliar litiase, hepatic insufficiency and liver congestion. Its effects are associated to the substance boldine that is present in its extract. In the present work, we evaluated the influence of boldine both in: (i) the structural conformation of a plasmid pUC 9.1 through gel electrophoresis analysis; and in (ii) the survival of the strain of Escherichia coli AB1157 submitted to reactive oxygen species (ROS), generated by a Fenton like reaction, induced by stannous chloride. Our results show a reduction of the lethal effect induced by stannous chloride on the survival of the E. coli culture in the presence of boldine. The supercoiled form of the plasmid is not modified by stannous chloride in the presence of boldine. We suggest that the protection induced by boldine could be explained by its anti-oxidant mechanism. In this way, the boldine could be reacting with stannous ions, protecting them against the oxidation and, consequently, avoiding the generation of ROS.

The effects of intraseptal injection of carbachol on natriuresis, kaliuresis and diuresis has been studied in conscious, unrestrained water-loaded male rats. Urinary sodium and potassium excretion increased following injections into the septal area. The intensity of the natriuresis and kaliuresis was dose-related. An antidiuretic effect was also observed. The Na + /K + ratio increased with increasing doses of carbachol, indicating that the rise in urinary sodium exceeded that of potassium. Systematic mapping of the septal area yielded about the same results for all sites, excepting a zone located in the anterior-dorsal part of the medial nucleus which appeared more sensitive. The natriuretic effect of intraseptal carbachol in adrenalectomized rats demonstrated the secondary role played by the adrenals. Contrariwise the decrease of the natriuretic effect observed either in hypophysectomized rats or in rats bearing a median eminence lesion receiving intraseptal carbachol showed the important participation of these structures in urinary Na + excretion. Adrenalectomy or median eminence lesions did not modify the kaliuretic response while hypophysectomy produced a transitory diminution. This fact favours the hypothesis of different mechanisms involved in Na + and K + excretion following intraseptal carbachol. These results leave open the question as to mechanism of action but suggest a possible role of the pituitary in mediating the responses. Also, the possibility of a role played by hemodynamic shifts is suggested.

The effect of intraseptal injection of carbachol and nicotine on urinary output of Na+ and K+ in untreated rats as well as in animals pretreated with locally injected atropine, hexamethonium, dibenamine and propranolol was studied in order to evaluate the relative role played by central muscarinic and nicotinic receptors in the regulation of salt and water renal excretion. The injection of 30-250 nmol of nicotine into the medial septal area caused a dose-dependent increase in Na+ and K+ urinary output whereas urine volume was little affected. The effect of 30 nmol of nicotine was blocked by pretreatment with 100 nmol of hexamethonium. In addition, pretreatment with 5 nmol of either hexamethonium or atropine partially antagonized the natriuretic and kaliuretic effect of 1 nmol of carbachol. Also the alpha-blocking agent, dibenamine (150 nmol) antagonized, while the beta-blocker, propranolol (100 nmol) significantly enhanced the effect of carbachol. Propranolol (100 nmol) alone caused a small, but significant increase in Na+ and K+ renal excretion. These results indicate that stimulation of both muscarinic and nicotinic receptors in the septal area, as caused by carbachol, elicits increased disposition of Na+ and K+ by the kidneys. Also, part of the effects of carbachol appear to be mediated by the release of endogenous catecholamines, acting on central alpha receptors to increase Na+ and K+ urinary excretion. On the other hand, simultaneous activation of beta-receptors by the released amines would partially inhibit this effect.

In this study, the participation of the adenylcyclase - cAMP system of the rat septal area in the mediation of the natriuretic, kaliuretic and diuretic effects of noradrenaline (NA) was investigated. The intraseptal injection of 20 nmol of NA caused a significant increase in the urinary excretion of Na+ and K+ as well as in the urinary volume during the 2 hr period following the intracerebral injection which was blocked by 40 nmol of phentolamine, locally injected, 30 min before the catecholamine. In contrast, pretreatment with propranolol (100 nmol) potentiated the effects of NA on salt and water renal excretion. The intraseptal injection of 3.12 to 50 nmol of dibutyryl cyclic adenosine monophosphate (db cAMP) caused dose-dependent increase in natriuresis and kaliuresis, but a decrease in urinary volume. Under the same experimental conditions, caffeine administration (6.25 to 100 nmol) also induced dose-dependent increases in Na+ and K+ urinary output. These results indicate that the saluretic effect of NA may be mediated by an alpha receptor-induced activation of the adenylcyclase - cAMP system in the septal area.

In order to evaluate the relative roles played by the central beta-receptors in the regulation of renal excretion of Na+, K+ and urine volume a study was carried out on the effect of intraseptal injections of isoproterenol on untreated rats and on rats pretreated with locally injected butoxamine and practolol. Injection of 20–160 nmol isoproterenol into the median septal area elicited a dose dependent decrease in Na+, K+ and urinary volume. Intraseptal injection of 40 nmol isoproterenol elicited a significant decrease in Na+ urinary excretion and in urinary volume during the 2 hr period immediately following injection. This effect was blocked by 160 nmol of locally injected butoxamine administered before isoproterenol. In contrast, pretreatment with practolol (160 nmol) did not alter the effect induced by isoproterenol. Pretreatment with these beta1 and beta2 antagonists did not abolish the effect of isoproterenol on K+ urinary excretion. The beta2 agonist agents, terbutaline and salbutamol, elicited a significant decrease in renal excretion of water and of the two salts. These results indicate that activation of beta2 receptors in the septal area elicits a decrease in Na+ and urinary volume excretion, while the same effect on K+ cannot be described as being due to type 2 beta-receptors.

Rats bearing lesions in the septal area followed by lesions in the subfornical organ were submitted to various thirst-eliciting procedures. The rats with hyperdipsia induced by lesions of the septal area drank more water than either during the control period or after lesion of the subfornical organ under the same thirst-eliciting or angiotensin-liberating stimuli (polyethyleneglycol, isoproterenol, water deprivation and ligation of the inferior vena cava). The overdrinking elicited by lesions in the septal area was blocked after lesion of the subfornical organ. Neither hypovolemia, nor hypotension or water deprivation could elicit increased water intake in animals whose subfornical organ had been destroyed. Animals with lesions in the subfornical organ showed decreased water intake after cellular dehydration. The results obtained suggest that the subfornical organ acts as a more important structure than the septal area in the regulation of water intake elicited by angiotensin, with two opposite effects: a direct one facilitating water intake, and an indirect one inhibiting the septal area. The septal area has an inhibitory effect on the subfornical organ and on water intake.