The survival and growth of hybrid Clarias gariepinus and Heterotis longifilis fed with live and frozen Dapthnids

Six glass tanks, each containing dechlorinated tap water and stocked with 3-day-old Heterobranchus, larvae hybrid between, Heterobranchus longifilis (male and Clarias gariepinus (female) were administered two types of feeding trials viz: live and frozen Dapthnids. Each treatment was replicated three times. The larvae were each fed approximately 50 Dapthnids per feeding time for fifteen days. Morphometric measurements of weigh and total length were taken before and after the experiment, and water quality parameters were monitored throughout the experimental period. At the end of the experiment, fish larvae fed frozen, Dapthnids, showed higher survival rate than Heterobranchus fed live Dapthnids. Even though the statistical analysis revealed that there was no significant difference (P>0.05) in survival. However, the Heteroclarias fed live dapthnids performed better in terms of growth rate than Heteroclarias fed frozen dapthnids. The statistical analysis did not show significant difference (P>0.05) between the final length and weight of two treatments. Heteroclarias fed live dapthnids had higher length and weight than Heteroclarias fed frozen dapthnids. It was therefore concluded that based on this experiment there is the likelihood that frozen zooplankton (Daphnids) do not encourage growth of Heteroclarias, but improves its survival. However, it's suggested that frozen zooplankton can be used to supplement live zooplankton in situation of sacrcity

Aplicações de métodos de classificação e calibração multivariada acoplados com técnicas espectroscópicas em amostras ambientais e alimentos

Este trabalho de pesquisa descreve dois estudos de caso de métodos quimiométricos empregados para a quantificação de hidrocarbonetos policíclicos aromáticos HPAs (naftaleno, fluoreno, fenantreno e fluoranteno) em água potável usando espectroscopia de fluorescência molecular e a classificação e caracterização de sucos de uva e seus parâmetros de qualidade através de espectroscopia de infravermelho próximo. O objetivo do primeiro estudo é a aplicação combinada de métodos quimiométricos de segunda ordem (N-PLS, U-PLS, U-PLS/RBL e PARAFAC) e espectrofluorimetria para determinação direta de HPAs em água potável, visando contribuir para o conhecimento do potencial destas metodologias como alternativa viável para a determinação tradicional por cromatografia univariada. O segundo estudo de caso destinado à classificação e determinação de parâmetros de qualidade de sucos de uva, densidade relativa e teor de sólidos solúveis totais, foi medida por espectroscopia de infravermelho próximo e métodos quimiométricos. Diversos métodos quimiométricos, tais como HCA, PLS-DA, SVM-DA e SIMCA foram investigados para a classificação amostras de sucos de uva ao mesmo tempo que métodos de calibração multivariada de primeira ordem, tais como PLS, iPLS e SVM-LS foram usadas para a predição dos parâmetros de qualidade. O princípio orientador para o desenvolvimento dos estudos aqui descritos foi a necessidade de metodologias analíticas com custo, tempo de execução e facilidade de operação melhores e menor produção de resíduos do que os métodos atualmente utilizados para a quantificação de HPAs, em água de torneira, e classificação e caracterização das amostras de suco de uva e seus parâmetros de qualidade

Effect of crude oil and some petroleum products on Clarias Gariepinus fingerlings (Catfish: Claridae)

Ninety (90) hatchery bred fingerlings of Clarias gariepinus (mean weight: 0.96 ± 0.1g) were randomly placed in 15 plastic baths (25 litres each) at the Research laboratory and were exposed to different concentrations of oil products to determine their effects on the fish, to facilitate inferential deductions that will enhance effective aquatic environmental management. Three (3) replicate basins of 5 experimental treatments (crude oil, petrol oil, kerosene oil, engine oil and control) were used at a concentration of 1.25ml. L-1. The control experiment was devoid of oil treatment. Six (6) fingerlings were placed in each replicate basin, flooded with 20 litres of clean tap water and fed with nutrafin cichilid food, 2 times daily at 3% body weight. The results showed that the feeding behaviour and swimming performances of fish were reduced after 24 hours of the addition of the various oil pollutants. Mortality of fingerlings in the oiled basins increased as the hours of exposure increased (i.e. 24, 48, 72 and 96 hours). Recovery was not immediate in the treated basin while surviving fingerlings in the control basins grew up to post-fingerlings after 90 days (3 months). There were significant differences (P<0.01 and P<0.05) in the effect of crude oil and the petroleum products on the mortality rate of C. gariepinus when exposed to oil pollutants at 1.25ml. L-1 concentration

Efeitos da exposição combinada de cafeína e etanol durante o desenvolvimento na atividade locomotora de camundongos adolescentes

O Transtorno do Déficit de Atenção e Hiperatividade (TDAH) é uma desordem neurocomportamental caracterizada por graus variados de desatenção, atividade motora excessiva e impulsividade. Sua etiologia não é completamente conhecida, porém, um grande número de evidências sugere que, além de fatores de risco genéticos, a exposição gestacional ao etanol e a altas doses de cafeína contribuem para a manifestação deste transtorno. O etanol, presente na composição de bebidas alcoólicas, e a cafeína, presente na composição de diversas bebidas (refrigerantes, chás, café, e energéticos), alimentos derivados do cacau e medicamentos estão entre as substâncias neuroativas mais consumidas no mundo. Apesar das evidências epidemiológicas do uso combinado de cafeína e etanol por gestantes, as interações entre estas substâncias têm recebido pouca atenção em estudos experimentais. Este fato é particularmente importante visto que alguns estudos apontam que cafeína é capaz de ampliar alguns aspectos importantes da ação de outras substâncias com potencial neurotóxico. Nesse estudo avaliamos os efeitos da co-exposição à cafeína e ao etanol durante o desenvolvimento na atividade locomotora em camundongos adolescentes. Para tanto, camundongos Suíços foram expostos do primeiro dia gestacional até o vigésimo primeiro dia pós-natal (PN21), a solução de cafeína 0,1g/L (Grupo CAF1, 10 ninhadas), a solução de cafeína 0,3g/L (Grupo CAF3, 10 ninhadas) ou tiveram acesso à água potável (Grupo CAF0, 10 ninhadas). Em dias alternados de PN2 a PN8, os animais de cada ninhada receberam uma injeção intraperitoneal de 0,25 l/g de etanol (grupo ETOH25), 0,5 l/g de etanol (grupo ETOH50) ou de solução salina (grupo ETOH0). Em PN30, a atividade locomotora foi avaliada por 15 minutos no teste de Campo Aberto. A análise dos níveis de etanol sérico, realizada em uma amostra independente de animais em PN8, indicou que, para as duas doses de etanol, a alcoolemia dos animais do grupo CAF3 foi significativamente maior do que as dos grupos CAF0 e CAF1, que não diferiram entre si. No teste de campo aberto, apenas os animais expostos ao etanol apresentaram aumento da atividade locomotora. Tanto o grupo ETOH25 quanto o grupo ETOH50 tiveram a atividade maior que o grupo ETOH0. A exposição à cafeína, por si só, não afetou a atividade locomotora dos animais nem potencializou os efeitos do etanol. No grupo CAF3, a atividade locomotora não foi afetada pela exposição ao etanol. Nossos dados confirmam o papel da exposição precoce ao etanol na manifestação da hiperatividade locomotora. Além disso, a exposição à cafeína durante o desenvolvimento pode exercer um papel protetor para a manifestação da hiperatividade locomotora induzida pela exposição precoce ao etanol.

RESPONSES OF Elodea nuttallii AND Ceratophyllum demersum TO HIGH TEMPERATURE

There were large losses of exotic species Elodea nuttallii during summer in eutrophic lakes of the middle and lower reaches of the Yanatze River, China. To investigate the main causes, the heat tolerance of E. nuttallii was studied and compared with that of native species Ceratopkyllum demersum by using an aquaria system in the laboratory. Under 4500 lx light intensity and 12-h L/12-h D cycle, E. nuttallii cultured in 1/5 Hoaglands solution at 39 degrees C showed a positive growth rate during the first 15 days, and the growth rate was higher than that at 35 degrees C. But after 15 days, the growth rates became negative for those cultured both at 39 and 35 degrees C. However, the growth rate was positive for more than 20 days for those cultured at 25 degrees C. Under the same conditions, the growth rate, productivity and chlorophyll content of E. nuttallii were significantly higher than that of C. demersum. Heat tolerance of E. nuttallii was also stronger than that of C. demersum. The optimal temperature for the growth of the two plants depended on the experimental period: both plants grew at an optimal rate at higher temperature if the experimental period was short; nevertheless the plants achieved optimal growth at a lower temperature if the experiment was conducted for a longer period. At the same light intensity, the heat tolerance of C. demersum in tap water with sediment was markedly stronger than that of E. nuttallii at 39 degrees C. Average growth rate of C. demersum was 4.5 times higher than that of E. nuttallii within 25 days. The positive growth period lasted for less than 25 days for E. nuttallii and for more than 25 days for C. demersum. When they were cultured in 1/5 Hoaglands solution and in tap water with sediment, the growth rate of C. demersum increased from 0.4 to 79.4 mg/d.g fresh weight (FW) within 20 days. E. nuttallii increased from 8.3 to 24.4 mg/d-g FW within 20 days. Both grew better in tap water with sediment than in 1/5 Hoaglands solution. The results demonstrated that the nutritional status of the water other than the high temperature affected the heat tolerance of E. nuttallii during summer. E. nuttallii has great ecological safe risk in China.

Determination of heavy metal ions by capillary electrophoresis with contactless conductivity detection after field-amplified sample injection

A method has been developed for determining of heavy metal ions by field-amplified sample injection capillary electrophoresis with contactless conductivity detection. The effects of the 2-N-morpholinoethanesulfonic acid/histidine (MES/His) concentration in the sample matrix, the injection time and organic additives on the enrichment factor were studied. The results showed that MES/His with a low concentration in the sample matrix, an increase of the injection time and the addition of acetonitrile improved the enrichment factor. Four heavy metal ions (Zn2+, Co2+, Cu2+ and Ni2+) were dissolved in deionized water, separated in a 10 mM MES/His running buffer at pH 4.9 and detected by contactless conductivity detection. The detection sensitivity was enhanced by about three orders of magnitude with respect to the non-stacking injection mode. The limits of detection were in the range from 5 nM (Zn2+) to 30 nM (Cu2+). The method has been used to determine heavy metal ions in tap water.

Ordering effects and choice set awareness in repeat-response stated preference studies

We present an experiment designed to investigate the presence and nature of ordering effects within repeat-response stated preference (SP) studies. Our experiment takes the form of a large sample, full-factorial, discrete choice SP exercise investigating preferences for tap water quality improvements. Our study simultaneously investigates a variety of different forms of position-dependent and precedent-dependent ordering effect in preferences for attributes and options and in response randomness. We also examine whether advanced disclosure of the choice tasks impacts on the probability of exhibiting ordering effects of those different types. We analyze our data both non-parametrically and parametrically and find robust evidence for ordering effects. We also find that the patterns of order effect in respondents' preferences are significantly changed but not eradicated by the advanced disclosure of choice tasks a finding that offers insights into the choice behaviors underpinning order effects. © 2011 Elsevier Inc.

Disinfection of Burkholderia cepacia complex from non-touch taps in a neonatal nursery

Burkholderia cepacia complex (Bcc) comprises nine closely related species or genomovars. It is an important causative agent of opportunistic infections and waterborne nosocomial infections. B. cepacia (formerly genomovar I) was identified from the blood culture of a baby in our neonatal unit (NU) in March 2005. B. cepacia was isolated four times from clinical specimens since the introduction of non-touch taps in the NU from 2000 to 2005 and only once from 1994 to 2000. Environmental samples were collected from the NU, including tap water from non-touch taps. Clinical and environmental isolates of Bcc were characterized using molecular identification and strain typing. A literature review was undertaken to delineate a method for eradication of Bcc. Several variations for hot water eradication of the organism from the taps were attempted. Genotyping and molecular analysis revealed that tap water isolates were B. cenocepacia which was a different species from the B. cepacia isolated from blood cultures of the neonate. However, B. cenocepacia has been known to cause nosocomial outbreaks and it was eventually eradicated from the NU by using repeated thermal shock (hot water at 65 degrees C for 10 min), changing taps and decolonizing sinks with hypochlorite. Molecular typing is useful in assisting the investigation of Bcc nosocomial infections.

Immunological determination of the pharmaceutical diclofenac in environmental and biological samples

A highly sensitive and specific competitive ELISA on 96-microwell plates was developed for the analysis of the nonsteroidal anti-inflammatory drug diclofenac. Within the water cycle in Europe, this is one of the most frequently detected pharmaceutically active compounds. The LOD at a signal-tonoise ratio (S/N) of 3, and the IC ₅₀, were found to be 6 ng/L and 60 ng/L respectively in tap water. In a comparative study using ELISA and GC-MS, diclofenac levels in wastewater from 21 sewage treatment plants were determined and a good correlation between these methods was found (ELISA vs. GCMS: r = 0.70, slope = 0,90, intercept = 0.37, n = 24). An average degradation rate of -25% can be calculated. Labscale-experiments on the elimination of diclofenac in continuous pilot sewage plants revealed a removal rate of only 5% over a period of 13 weeks. In a further study, the ELISA was applied to a number of extracts of various animal tissues from a range of species, and again a very good relationship between ELISA and LC-ESI/MS data sets was obtained (r = 0.90, p<0.0001; n = 117). The ELISA has proven to be a simple, rapid, reliable and affordable alternative to otherwise costly and advanced techniques for the detection of diclofenac in matrix diverse water samples and tissue extracts after only relatively simple sample preparation. © 2007 American Chemical Society.

Response to salinity in young olive trees of three Iberian varieties

Soil salinization is a problem in the Mediterranean region. This paper reports a research on the response to salt in two year-old olive trees (Olea europaea L.) of three Iberian varieties: Arbequina, Cobrançosa and Galega Vulgar. Plants were grown in plastic pots containing approximately 9 Kg of a sandy granitic soil, on a greenhouse at the University of Évora since February 2010. The experiment went from February to April 2012. As a rule, plants were watered every other day alternating salt solution (0 mM, 80 mM or 200 mM NaCl) or tap water. After three months irrigation with the different NaCl solutions, soil electric conductivity and soil water content were significantly higher on salt-irrigated pots. Salt also decreased significantly stomatal conductance (gs) and mid-day leaf water potential (), Cobrançosa having in general higher gs and but lower SLA than the two other varieties. Chlorophyll content of leaves was not affected by salt after this three months exposure to NaCl but was significantly higher on Arbequina and lower on Cobrançosa. In general, hyperspectral reflectance indexes did not show significant correlations with salt irrigation, except for the Photochemical Reflectance Index (PRI) which was clearly lower on plants of all three varieties irrigated with salt. Interestingly, Cobrançosa showed frequently vegetation indexes different from the other two varieties.

Effects of active pharmaceutical ingredients in mussel mytilus galloprovincialis

More than 3000 types of active pharmaceutical ingredients (APIs) are applied in Human and veterinary medicine practice. These compounds are considered an emergent class of environmental contaminants with the ability to cause damage and unexpected effects to aquatic organisms, namely in species of high commercial value. APIs are ubiquitous in the environment being frequently detected in influents and effluents of waste water treatment plants (WWTPs), surface waters and more distressingly in the public tap water in concentrations ranging from ng to μg.L-1. Considering these premises, the present thesis focused on APIs detection in the Arade river water, the impact of summer period in APIs’ concentration alterations applying the passive sampler device, POCIS (polar organic compound integrative sampler), as well as, the assessment of the effects caused by non-steroidal anti-inflammatory drugs (NSAID) ibuprofen (IBU) and diclofenac (DCF) and antidepressant selective serotonin reuptake inhibitor (SSRI) fluoxetine as single and mixture exposures along with a classical contaminant copper (Cu) on a non-target species, mussel Mytilus galloprovincialis. For this purpose, a multibiomarker approach was applied namely including biomarkers of oxidative stress (antioxidant enzymes activities of superoxide dismutase – SOD, catalase – CAT, glutathione reductase – GR and Phase II glutathione-S-transferase), damage - lipid peroxidation (LPO), neurotoxic effects (through the activity of acetylcholinesterase enzyme - AChE) and endocrine disruption (through vitellogenin-like proteins measurement applying the indirect method of alkali-labile phosphate - ALP) after exposure of mussel species’ to selected APIs at environmental relevant concentrations. The main results highlighted the occurrence of 19 APIs in the river Arade from several distinct therapeutic classes. Stimulant caffeine, antiasthmatic theophylline, NSAID ibuprofen and analgesic paracetamol presented the highest concentrations. Summer impact was inconclusive due to each API transient concentration in each month. The multibiomarker results revealed distinct responses towards each selected API (as single exposure or as mixtures) that were tissue and time dependent. Several multistressor interactions were proposed for each biomarker. The results also revealed APIs potential to induce oxidative stress, LPO, neurotoxicity and endocrine disruption even at extremely low concentrations on a species extremely vulnerable to APIs presence highlighting the urgency on the development of methodologies able to prevent its entrance in the aquatic environment.

“Green Electrodes” Modified with Au Nanoparticles Synthesized in Glycerol, as Electrochemical Nitrite Sensor

A new environmentally friendly Au nanoparticles (Au NPs) synthesis in glycerol by using ultraviolet irradiation and without extra-added stabilizers is described. The synthesis proposed in this work may impact on the non-polluting production of noble nanoparticles with simple chemicals normally found in standard laboratories. These Au NPs were used to modify a carbon paste electrode (CPE) without having to separate them from the reaction medium. This green electrode was used as an electrochemical sensor for the nitrite detection in water. At the optimum conditions the green sensor presented a linear response in the 2.0×10−7–1.5×10−5 M concentration range, a good detection sensitivity (0.268 A L mol−1), and a low detection limit of 2.0×10−7 M of nitrite. The proposed modified green CPE was used to determine nitrite in tap water samples.

Taenia solium transmission in a rural community in Honduras : an examination of risk factors and knowledge

Taenia soliurn taeniasis and cysticercosis are recognized as a major public health problem in Latin America. T. soliurn transmission not only affects the health of the individual, but also social and economic development, perpetuating the cycle of poverty. To determine prevalence rates, population knowledge and risk factors associated with transmission, an epidemiological study was undertaken in the rural community of Jalaca. Two standardized questionnaires were used to collect epidemiological and T. soli urn general knowledge data. Kato-Katz technique and an immunoblot assay (EITB) were used to determine taeniasis and seroprevalence, respectively. In total, 139 individuals belonging to 56 households participated in the study. Household characteristics were consistent with conditions of poverty of rural Honduras: 21.4% had no toilet or latrines, 19.6% had earthen floor, and 51.8% lacked indoor tap water. Pigs were raised in 46.4% of households, of which 70% allowed their pigs roaming freely. A human seroprevalence rate of 18.7% and a taeniasis prevalence rate of 2.4% were found. Only four persons answered correctly 2: 6 out of ten T. soliurn knowledge questions, for an average passing score of 2.9%. In general, a serious gap exists in knowledge regarding how humans acquire the infections, especially neurocysticercosis was identified. After regression analysis, the ability to recognize adult tapeworms and awareness of the clinical importance of taeniasis, were found to be significant risk factors for T. soliurn seropositivity. These results demonstrate a high level of transmission and a low level of kn~,wledge about Taenia soliurn in Jalaca. Consequently, intervention measures integrated with health education are necessary to decrease the burden caused by this parasite.

Développement de méthodes analytiques pour la détection et la quantification de traces de produits pharmaceutiques dans les eaux du fleuve Saint Laurent

Le présent projet vise à documenter la nécessité d’augmenter notre connaissance de la présence des contaminants organiques tels que les médicaments dans l’environnement et d’évaluer leur devenir environnemental. On a étudié la présence de composés pharmaceutiques dans différents échantillons d'eau. On a focalisé nos efforts spécialement sur les échantillons d'eau de l'usine d'épuration de la Ville de Montréal et ses effluents, les eaux de surface avoisinantes et l’eau du robinet dans la région de Montréal. Pour ce faire, on a tout d’abord développé deux méthodes analytiques automatisées basées sur la chromatographie liquide avec extraction en phase solide (SPE) couplée à la chromatographie liquide couplée à la spectrométrie de masse en tandem (LC-MS/MS). On a également étudié les performances des trois techniques d'ionisation à pression atmosphérique (API), pour ensuite les utiliser dans la méthode analytique développée. On a démontré que l'ionisation par électronébulisation (ESI) est une méthode d'ionisation plus efficace pour l'analyse des contaminants pharmaceutiques dans des échantillons de matrices très complexes comme les eaux usées. Une première méthode analytique SPE couplée à la LC-MS/MS a été développée et validée pour l'étude des échantillons complexes provenant de l'usine d'épuration de la Ville de Montréal et des eaux de surface près de l'usine. Cinq médicaments de prescription ont été étudiés: le bézafibrate (un régulateur de lipides), le cyclophosphamide et le méthotrexate (deux agents anticancéreux), l'orlistat (un agent anti-obésité) et l’énalapril (utilisé dans le traitement de l'hypertension). La plupart de ces drogues sont excrétées par le corps humain et rejetées dans les eaux usées domestiques en faisant par la suite leur chemin vers les usines municipales de traitement des eaux usées. On a pu démontrer qu'il y a un faible taux d’élimination à l'usine d'épuration pour le bézafibrate et l'énalapril. Ces deux composés ont aussi été détectés dans les eaux de surface sur un site à proximité immédiate de la décharge de l’effluent de la station d'épuration. i En observant la nécessité de l'amélioration des limites de détection de la première méthode analytique, une deuxième méthode a été développée. Pour la deuxième méthode, un total de 14 contaminants organiques, incluant trois agents anti-infectieux (clarithromycin, sulfaméthoxazole et triméthoprime), un anticonvulsant (carbamazépine) et son produit de dégradation (10,11-dihydrocarbamazépine), l'agent antihypertensif (enalapril), deux antinéoplastiques utilisés en chimiothérapie (cyclophosphamide et méthotrexate), des herbicides (atrazine, cyanazine, et simazine) et deux produits de transformation de l’atrazine (deséthylatrazine et déisopropylatrazine) ainsi qu’un agent antiseptique (triclocarban). Ces produits ont été quantifiés dans les eaux de surface ainsi que dans l’eau du robinet. L'amélioration des limites de détection pour cette méthode a été possible grâce à la charge d'un volume d'échantillon supérieur à celui utilisé dans la première méthode (10 mL vs 1 mL). D'autres techniques de confirmation, telles que les spectres des ions produits utilisant une pente d’énergie de collision inverse dans un spectromètre de masse à triple quadripôle et la mesure des masses exactes par spectrométrie de masse à temps d’envol, ont été explorées. L'utilisation d'un analyseur de masse à temps d’envol a permis la confirmation de 6 des 14 analytes. Finalement, étant donné leur haute toxicité et pour évaluer leur persistance et leur transformation au niveau du traitement des eaux potables, la cinétique d'oxydation du cyclophosphamide et de méthotrexate avec l'ozone moléculaire et des radicaux OH a été étudiée. Les constantes de dégradation avec l'ozone moléculaire ont été calculées et la qualité de l'eau après traitement a pu être évaluée. Le rendement du processus d'ozonation a été amélioré pour la cyclophosphamide dans les eaux naturelles, en raison de la combinaison de réactions directes et indirectes. Cette étude a montré que l'ozone est très efficace pour oxyder le méthotrexate mais que le cyclophosphamide serait trop lent à s’oxyder pour un traitement efficace aux conditions usuelles de traitement de l’eau potable.

Efficacy of Microwaves and Chlorhexidine on the Disinfection of Pacifiers and Toothbrushes: An In Vitro Study

Purpose: The purpose of this study was to evaluate, in vitro, the contamination of toothbrushes and pacifiers by Streptococcus mutans, and the efficacy of microwave and chlorhexidine for their disinfection. Methods: Sixty pacifiers and 60 toothbrushes were contaminated with S mutans and then divided into groups according to the disinfection protocol: Group 1-chlorhexidine solution; Group 2-microwave sterilization; and Group 3-sterile tap water. The devices were evaluated microbiologically as to the formation of S mutans colonies/biofilms and were examined by scanning electron microscopy. The results were submitted for statistical analysis by Friedman`s test at a 5% significance level. Results: The results of both types of evaluation showed a large number of S mutans colonies/biofilms after spraying with sterile tap water, and chlorhexidine spraying and microwaving were effective in eliminate colonies/biofilms. Groups 1 and 2 were statistically similar to each other (P>.05) and differed significantly from Group 3 (P<.05). Conclusions: The 0.12% chlorhexidine solution spray and 7 minutes of microwave irradiation were effective for disinfection of pacifiers and toothbrushes. (Pediatr Dent 2011;33:10-3) Received July 29, 2009 I Last Revision January 26, 2010 I Accepted March 10, 2010