The elevated gradient of aversion: a new apparatus to study the rat behavior dimensions of anxiety, fear, and impulsivity.

Few behavioral tests allow measuring several characteristics and most require training, complex analyses, and/or are time-consuming. We present an apparatus based on rat exploratory behavior. Composed of three different environments, it allows the assessment of more than one behavioral characteristic in a short 3-min session. Factorial analyses have defined three behavioral dimensions, which we named Exploration, Impulsivity, and Self-protection. Behaviors composing the Exploration factor were increased by chlordiazepoxide and apomorphine and decreased by pentylenetetrazole. Behaviors composing the Impulsivity factor were increased by chlordiazepoxide, apomorphine, and both acute and chronic imipramine treatments. Behaviors composing the Self-protection factor were decreased by apomorphine. We submitted Wistar rats to the open-field test, the elevated-plus maze, and to the apparatus we are proposing. Measures related to exploratory behavior in all three tests were correlated. Measures composing the factors Impulsivity and Self-protection did not correlate with any measures from the two standard tests. Also, compared with existing impulsivity tests, the one we proposed did not require previous learning, training, or sophisticated analysis. Exploration measures from our test are as easy to obtain as the ones from other standard tests. Thus, we have proposed an apparatus that measured three different behavioral characteristics, was simple and fast, did not require subjects to be submitted to previous learning or training, was sensitive to drug treatments, and did not require sophisticated data analyses.

The elevated gradient of aversion: a new apparatus to study the rat behavior dimensions of anxiety, fear, and impulsivity

Few behavioral tests allow measuring several characteristics and most require training, complex analyses, and/or are time-consuming. We present an apparatus based on rat exploratory behavior. Composed of three different environments, it allows the assessment of more than one behavioral characteristic in a short 3-min session. Factorial analyses have defined three behavioral dimensions, which we named Exploration, Impulsivity, and Self-protection. Behaviors composing the Exploration factor were increased by chlordiazepoxide and apomorphine and decreased by pentylenetetrazole. Behaviors composing the Impulsivity factor were increased by chlordiazepoxide, apomorphine, and both acute and chronic imipramine treatments. Behaviors composing the Self-protection factor were decreased by apomorphine. We submitted Wistar rats to the open-field test, the elevated-plus maze, and to the apparatus we are proposing. Measures related to exploratory behavior in all three tests were correlated. Measures composing the factors Impulsivity and Self-protection did not correlate with any measures from the two standard tests. Also, compared with existing impulsivity tests, the one we proposed did not require previous learning, training, or sophisticated analysis. Exploration measures from our test are as easy to obtain as the ones from other standard tests. Thus, we have proposed an apparatus that measured three different behavioral characteristics, was simple and fast, did not require subjects to be submitted to previous learning or training, was sensitive to drug treatments, and did not require sophisticated data analyses.

Methane Cracking over Cobalt Molybdenum Carbides.

ABSTRACT: The catalytic behaviour of Co3Mo3C, Co6Mo6C, Co3Mo3N and Co6Mo6N for methane cracking has been studied to determine the relationship between the methane cracking activity and the chemical composition. The characterisation of post-reaction samples showed a complex phase composition with the presence of Co3Mo3C, α-Co and ß-Mo2C as catalytic phases and the deposition of different forms of carbon during reaction.

Early maternal separation induces preference for sucrose and aspartame associated with increased blood glucose and hyperactivity.

Early life stress and exposure to sweeteners lead to physiological and behavioral alterations in adulthood. Nevertheless, many genetic and environmental factors as well as the neurobiological mechanisms that contribute to the development of these disorders are not fully understood. Similarly, evidence about the long-term metabolic effects of exposure to sweeteners in early life is limited and inconsistent. This study used an animal model of maternal separation during breastfeeding (MS) to analyze the effects of early life stress on consumption of sweeteners, weight gain, blood glucose and locomotion. Rats were housed under a reversed light/dark cycle (lights off at 7:00 h) with ad libitum access to water and food. In the MS protocol, MS pups were separated from the dam for 6 h per day in two periods of 180 minutes (7:00-10:00 and 13:00-16:00 h) during the dark phase of postnatal day (PND) 1 to PND 21. Non-separated (NS) pups served as controls. On PND 22 rats were grouped by sex and treatment. From PND 26 to PND 50 sucrose and aspartame were provided to rats, and sweetener intake, body weight and blood glucose-related measures were scored. On PND 50, both male and female rats were exposed to the open field test to obtain locomotion and anxiety-related measures. Results showed that both early maternal separation and sweetener intake during adolescence resulted in increased blood glucose and hyperactivity in male rats but not in female rats. Data suggest that the combination of early stress and exposure to sucrose and aspartame could be a risk factor for the development of chronic diseases such as diabetes, as well as for behavioral alterations.

Carbonised red mud--a new water treatment product made from a waste material.

Proposals to use red mud, the waste produced by the extraction of alumina from bauxite ore in the Bayer process, as a material for treatment of heavy metal-contaminated water are limited by its inherent alkalinity and variability. Attempts to lower its pH have been largely unreliable. However, an alternative strategy is carbonisation of red mud by catalytic hydrocarbon cracking, which results in a magnetic material of greater surface area. The efficacy of this material has been compared with that of the untreated parent red mud and acidified red mud for the sorption of CrO(4)(2-), Cu(2+) and Pb(2+). Carbonised red mud does not remove CrO(4)(2-) from solution, but shows enhancement of Cu(2+) and Pb(2+) removal. There is an approximate ten-fold increase in removal of Cu(2+) and Pb(2+) by carbonised red mud compared with acidified red mud.

Physical-anaerobic-chemical process for treatment of dairy cattle manure.

An overall treatment process for the removal of nitrogen, methane production and obtention of valuable fertilizers from dairy manure has been investigated in laboratory scale. Solid and liquid fractions were separated by flocculation and screening. The solid fraction contained 81.6%, 84.4%, 58.6% and 85.2% of TS, VS, TKN-N and P(T) originally present in manure. Batch anaerobic digestion of this solid fraction at 50°C resulted in methane production of 29.0 L CH(4)/kg. The liquid fraction, free of suspended solids, was satisfactorily treated at 35°C in an upflow anaerobic sludge blanket reactor operating stably at an organic loading rate of 40.8 g COD/(L·d) reaching a methane production of 10.3 L CH(4)/(L·d). Accumulation of volatile fatty acids did not occur. Ammonia nitrogen concentration in the anaerobic effluent fluctuated between 850-1170 mg NH(4)(+)-N/L and was reduced to values less than 100mg NH(4)(+)-N/L by struvite precipitation.

Carbon deposition and phase transformations in red mud on exposure to methane.

A characterization study detailing the phase transformations and microstructural nature of the carbon deposited during methane decomposition over red mud has been undertaken. In situ XRD was carried out to study the phase transformation sequences of red mud during the reaction. Scanning electron microscopy, high resolution transmission electron microscopy, thermogravimetric analysis, BET surface area determination and CHN analysis were carried out to investigate the properties of the post-reaction samples. Exposure to methane with increasing temperature caused a stepwise reduction of iron oxides in red mud and promoted methane cracking leading to carbon deposition. The presence of carbon nanostructures was confirmed by HRTEM observations. The carbon formed was graphitic in nature and the spent red mud, rich in Fe and Fe(3)C formed as a result of the reduction of the iron oxide, was magnetic in nature. The surface area of the material was enhanced upon reaction. In addition, reactivity comparisons between goethite and red mud were carried out to study the formation of carbon oxides during reaction.

Evolution of composition of dairy manure supernatant in a controlled dung pit.

Anaerobic conversion of dairy manure into biogas is an attractive way of managing this waste. It is well known that the hydrolysis of large molecules into small, directly biodegradable ones is the rate limiting step of the overall anaerobic process. The present work studies the development of the hydrolytic and acidogenic stages of dairy manure with different solid concentrations (40, 60 and 80 g VS/L) at ambient temperature (20 degrees C). The purpose was to determine the operational conditions that provide a liquid fraction with a high soluble chemical oxygen demand (COD) and a high volatile fatty acids (VFA) content in manure before the methanogenic stage starts up. At 20 degrees C, the evolution of the studied parameters showed that, in a controlled plug-flow dung pit, the hydrolytic and acidogenic stages progressed moderately in a continuous way during the 25 days that the experimentation lasted, whereas no methanization was observed. Supernatant COD and VFA concentrations increased 30% and 107%, respectively, for the 60 g VS/L samples. Manure was also operated at 35 degrees C with a similar increase in supernatant COD but a higher increase in VFA, 154%. For both operational temperatures, the predominant VFAs were, in this order, acetic, propionic and butyric acids. During the operation at 35 degrees C, the methanogenic stage started between days 20 and 25 for the samples with lower solids content, i.e. 40 and 60 g VS/L.

Flocculants effect in biomass retention in a UASB reactor treating dairy manure.

The performance and biomass retention of an upflow anaerobic sludge bed (UASB) reactor treating liquid fraction of dairy manure has been investigated at several organic loading rates. Two identical UASB reactors were employed. The biomass of one UASB reactor (FBR) had previously been treated with a cationic polyacrylamide, the other reactor was operated as a control reactor (CR). At 3 and 2 days of HRT both reactors functioned similarly, but at 1.5 days HRT some differences were observed between both effluents. Mean COD(T) removal percentages were 83.4% and 76.5%; COD(VFA) values in effluents were 977 and 2682 mg l(-1) for the FBR and the CR respectively. The VSS initial value in both reactors was 25.66 g VSS, whereas after the experiment the quantities were 31.83 g VSS in the FBR and 23.18 g VSS in the CR reactors. Polymer addition resulted in a higher degree of biomass retention and better performance in the FBR reactor.

Characterisation of solid and liquid fractions of dairy manure with regard to their component distribution and methane production.

Dairy manure with a total solids content of 77.2g TS/l was separated by means of screening and coagulation-flocculation treatments, using CaO as coagulant and a cationic polyacrylamide as flocculant, obtaining liquid and solid fractions. The solid fraction separated contained 33.4% of the initial total mass of dairy manure plus chemical solutions, containing also 75.2% of the TS, 80.4% of the VS, 58.5% of the total Kjeldahl nitrogen (TKN) and 87.4% of the total phosphorus (P(T)) present in the initial dairy manure. 83.7% of the liquid fraction chemical oxygen demand (COD) was anaerobically biodegradable (COD(BD)). Methane production for the separated liquid fraction was 0.604l CH4 NCTP/g VS added, being 0.307 and 0.371l CH4 NCTP/g VS added for dairy manure and screened dairy manure, respectively. The characteristics of this liquid fraction would allow its treatment in high loading anaerobic reactors having shorter hydraulic retention times, smaller reactor size and a higher methane volumetric production rate than conventional anaerobic reactors treating either manure or screened manure.

Two-factor design for coagulant/flocculant doses effect for solid-liquid separation of dairy manure.

Screened dairy manure, with a total solids content equal to 34.7 g TS l(-1), was subjected to a coagulation-flocculation treatment using FeCl, as coagulant and a medium cationic polyacrylamide (MCP1). The effect of changing doses of the additives (FeCl3 and MCP1) on the properties of supernatant fractions was studied by means of design of response surface using "Statgraphics Plus 3.0" program. The results showed that the values of concentrations found in supernatants obtained after settling of the flocs for two of the dependent variables studied, filtrate chemical oxygen demand (CODf) and total organic carbon (TOC), were significantly influenced by both the FeCl3 and MCP1 doses at an error lower than 5%. The values of concentrations of the remaining variables studied (TS, VS, CODt, CODvfa) were significantly influenced only by the MCP1 dose at an error lower than 5%. The predictive model obtained the best satisfactory parameters for TOC supernatant's concentration (R2=0.980, F-ratio = 438.89 (p-value < 0.05)) and the worse for VS (R2 = 0.783, F-ratio = 33.43 (p-value < 0.05)).

Synthesis of MoS(2) nanorods and their catalytic test in the HDS of dibenzothiophene.

Partially sulfided nanostructures were synthesized by direct sulfurization of alpha-MoO(3) nanorods using a mixture of H(2)S/H(2), 15 vol%, at several temperatures (400, 500, 600, 700, and 800 degrees C). These materials were tested as catalysts in the hydrodesulfurization (HDS) of dibenzothiophene (DBT) and characterized by specific surface areas using the expression developed by Brunauer, Emmett, and Teller (BET equation), x-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The TEM images show a gradual evolution from a smooth surface to a rough material, presenting some type of holes all over the particles, but keeping their rod-like structure throughout sulfidation. The results of evaluating the catalysts in the HDS of DBT showed that the best temperature for sulfidation is 500 degrees C. In all samples, a higher selectivity for hydrogenation over sulfur removal was observed.

Prophylaxis in transurethral surgery: oral lomefloxacin versus intravenous cefuroxime.

A randomized study compared the efficacy of a single dose of lomefloxacin given orally vs. cefuroxime given intravenously for prophylaxis against urinary tract infection in patients who were undergoing transurethral surgery. Patient groups were demographically similar; 25 received 400 mg lomefloxacin orally 2-6 h before surgery and 26 received 1.5 g cefuroxime intravenously 30-90 min before surgery. Urine cultures were obtained prior to surgery, 24 h after surgery and 3-5 days after surgery or before hospital discharge. Treatment was considered successful if bacterial culture showed < 10(5) CFU/ml. Clinical results expressed as success/failure rates showed success in 18 patients in the lomefloxacin group (72%) and 15 patients in the cefuroxime group (57.7%). Results demonstrated that lomefloxacin is superior to cefuroxime when used as prophylaxis against urinary tract infection following transurethral surgery. In addition, lomefloxacin may be preferable because of its convenient single-dose oral administration.