Carbohydrates Concentration in leaves of potato plants affected by nitrogen fertilization rates

ABSTRACT At poor conditions of nitrogen (N) in the soil, potato plants may accumulate starch in leaves and be indicative of N nutritional stress. The objective of this work was to determine the effects of N rates (0, 50, 100, 200 and 300 kg ha-1 of N) on the concentrations of carbohydrates (total soluble sugars-TSS, reducing sugars-RS, non-reducing sugars-NRS and starch) in the fourth leaf (FL) of two potato cultivars (Asterix and Atlantic) and their critical levels (CL) associated to the N fertilization rate necessary to obtain the maximum physical (MPE) and economic (MEE) efficiency of tubers. A randomized block design with four replications was used in both experiments. On day 21 after plant emergence, four FL were collected from four plants. Potatoes plants fertilized with low rates of N accumulated less TSS in leaves than those properly fertilized. The opposite occurred with content of starch. The cultivars showed similar responses to five doses of N in relation to contents of starch and TSS. However, the response to the increase in doses of N for RS, NRS and Starch/NRS is cultivar-specific. The correlations between contents of RS, NRS and Starch/NRS with the starch and TSS were dependent on the potato cultivar.

Studies of the Antiproliferative Activity of Ruthenium (II) Cyclopentadienyl-Derived Complexes with Nitrogen Coordinated Ligands

Four cationic ruthenium(II) complexes with the formula [Ru(eta(5)-C5H5)(PPh3)(2)](+), with L = 5-phenyl-1H-tetrazole (TzH) 1, imidazole (ImH) 2, benzo[1,2-b; 4,3-b'] dithio-phen-2-carbonitrile (Bzt) 3, and [5-(2-thiophen-2-yl)-vinyl]-thiophene-2-carbonitrile] (Tvt) 4 were prepared and characterized in view to evaluate their potentialities as antitumor agents. Studies by Circular Dichroism indicated changes in the secondary structure of ct-DNA. Changes in the tertiary structure of pBR322 plasmid DNA were also observed in gel electrophoresis experiment and the images obtained by atomic force microscopy (AFM) suggest strong interaction with pBR322 plasmid DNA; the observed decreasing of the viscosity with time indicates that the complexes do not intercalate between DNA base pairs. Compounds 1, 2, and 3 showed much higher cytotoxicity than the cisplatin against human leukaemia cancer cells (HL-60 cells).

Evaluation of exposure index (IgM) in orthopaedic radiography

The exposure index (lgM) obtained from a radiographic image may be a useful feedback indicator to the radiographer about the appropriate exposure level in routine clinical practice. This study aims to evaluate lgM in orthopaedic radiography performed in the standard clinical environment. We analysed the lgM of 267 exposures performed with an AGFA CR system. The mean value of lgM in our sample is 2.14. A significant difference (P=0.000<0.05) from 1.96 lgM reference is shown. Data show that 72% of exposures are above the 1.96 lgM and 42% are above the limit of 2.26. Median values of lgM are above 1.96 and below 2.26 for Speed class (SC) 200 (2.16) and SC400 (2.13). The interquartile range is lower in SC400 than in SC200. Data seem to indicate that lgM values are above the manufacturer’s reference of 1.96. Departmental exposure charts should be optimised to reduce the dose given to patients.

Valor preditivo do "Clinical Risk Index for Babies" para o risco de mortalidade neonatal

OBJETIVO: Comparar o valor preditivo do CRIB (Clinical Risk Index for Babies) para o risco de mortalidade neonatal ao peso de nascimento (PN) e idade gestacional (IG). MÉTODO: Numa coorte prospectiva foram estudados, durante o ano de 1996, 71 recém-nascidos admitidos na unidade de terapia intensiva, com PN < 1.500 g e/ou IG < 31 semanas. RESULTADOS: A taxa de mortalidade foi de 29,6%; para PN < 1.000 g ou IG < 29 semanas foi de 60%, enquanto que para o escore de CRIB > 10 foi de 100%. CONCLUSÕES: O escore de CRIB > 10 correspondeu a maiores especificidade e valor preditivo positivo em relação aos demais parâmetros. A área determinada pela "receiver operating characteristic" relativa ao CRIB também foi superior. O CRIB mostrou-se um marcador mais acurado na previsão de risco de mortalidade quando comparado ao PN ou IG isoladamente.

Open and closed positions and stock index futures volatility

In this paper we analyze the relationship between volatility in index futures markets and the number of open and closed positions. We observe that, although in general both positions are positively correlated with contemporaneous volatility, in the case of S&P 500, only the number of open positions has influence over the volatility. Additionally, we observe a stronger positive relationship on days characterized by extreme movements of these contracting movements dominating the market. Finally, our findings suggest that day-traders are not associated to an increment of volatility, whereas uninformed traders, both opening and closing their positions, have to do with it.

Volatility regimes for the VIX index

This article presents a Markov chain framework to characterize the behavior of the CBOE Volatility Index (VIX index). Two possible regimes are considered: high volatility and low volatility. The specification accounts for deviations from normality and the existence of persistence in the evolution of the VIX index. Since the time evolution of the VIX index seems to indicate that its conditional variance is not constant over time, I consider two different versions of the model. In the first one, the variance of the index is a function of the volatility regime, whereas the second version includes an autoregressive conditional heteroskedasticity (ARCH) specification for the conditional variance of the index.

Genus and Braid Index Associated to Sequences of Renormalizable Lorenz Maps

We describe the Lorenz links generated by renormalizable Lorenz maps with reducible kneading invariant (K(f)(-), = K(f)(+)) = (X, Y) * (S, W) in terms of the links corresponding to each factor. This gives one new kind of operation that permits us to generate new knots and links from the ones corresponding to the factors of the *-product. Using this result we obtain explicit formulas for the genus and the braid index of this renormalizable Lorenz knots and links. Then we obtain explicit formulas for sequences of these invariants, associated to sequences of renormalizable Lorenz maps with kneading invariant (X, Y) * (S,W)*(n), concluding that both grow exponentially. This is specially relevant, since it is known that topological entropy is constant on the archipelagoes of renormalization.

Toxicidade a cianobactérias: impacte potencial na saúde pública em populações de Portugal e Brasil

Como recurso natural fundamental à vida, a água e os ecossistemas aquáticos devem ser alvo de avaliação contínua, no que se reporta à sua qualidade física, química e biológica. Segundo a Organização Mundial de Saúde cerca de 1,1 biliões de pessoas estão impossibilitadas em aceder a qualquer tipo de água potável e, as populações residentes nas proximidades de rios, lagoas, e reservatórios utilizam estas águas para as suas necessidades de consumo, aumentando o risco de transmissão de doenças. Enquanto constituintes da comunidade fitoplanctónica, as cianobactérias são microrganismos procariotas, fotossintéticos, que obtêm os nutrientes diretamente da coluna de água e, um aumento da concentração de nutrientes (principalmente azoto e fósforo), associado a condições ambientais favoráveis, pode desencadear um crescimento rápido originando fluorescências. Sob determinadas condições as cianobactérias podem produzir toxinas existindo registos que evidenciam que fluorescências toxicas são responsáveis pelo envenenamento agudo e morte de animais e humanos pelo que, a água utilizada para consumo humano deverá ser regularmente monitorizada para este elemento biológico. O objetivo deste estudo é relacionar a ocorrência de fluorescências de cianobactérias (> 2000 cel/ml) e toxicidade associada, com o impacte potencial na Saúde Pública avaliado através do consumo direto ou indireto da água. Em Portugal foram selecionados oito reservatórios situados na região Sul, pertencentes às bacias hidrográficas do Sado e Guadiana e estudados entre 2000 e 2008. No Brasil foram selecionados os reservatórios de Três Marias (Estado de Minas Gerais) e de Tucuruí (Estado do Pará) e estudados em 2005 e 2006 respetivamente. Os reservatórios foram caracterizados em termos físicos e químicos, tendo-se igualmente procedido à caracterização da comunidade fitoplanctónica através da identificação e quantificação dos principais grupos presentes em diferentes épocas do ano. Em termos fitoplanctónicos os reservatórios portugueses apresentaram maior diversidade,verificando-se contudo dominância das cianobactérias na comunidade. Associados a fluorescências, foram registados nestes reservatórios géneros produtores de hepato e neurotoxinas como Aphanizomenon sp, Microcystis aeruginosa e Oscillatoria sp. No Brasil, em situação de fluorescências, os géneros produtores de neuro e hepatotoxinas foram Microcystis (> 350.000 cels/ml) e Cylindrospermopsis. A presença destes géneros, poderá constituir um risco potencial para a saúde pública, pelo que é importante a implementação de medidas de mitigação em todos os reservatórios objeto de estudo, devendo essa atuação passar pelo controle do estado trófico no sentido de evitar o desenvolvimento de fluorescências. Assim sugere-se a implementação de um tratamento adequado para a produção de água de consumo e a organização de ações de sensibilização e aviso e informação às populações que utilizam os reservatórios em Portugal e no Brasil para diversos usos. - ABSTRACT - As a life fundamental natural resource, water and aquatic ecosystems must be continuously evaluated in their physical, chemical and biological quality. According World Health Organization, 1.1 billion people has no chance to access any kind of potable water. Populations living near rivers, lagoons or reservoirs use those waters to content their needs, increasing risks disease transmission. As members of phytoplankton community, cyanobacteria are prokaryotic, photosynthetic microorganisms and get its nutrients directly from water column. The increase of this nutrients (especially nitrogen and phosphorus) associated with favorable environment conditions, can support a sudden grow and instigate blooms. Under specific conditions cyanobacteria can produce toxins and several records have shown that toxic blooms are responsible by acute poisoning and death in animals and humans so, water for human consumption must be regularly surveyed for this biologic element. The aim of this study is to correlate Cyanobacteria blooms (>2.000cels/ml) and connected toxicity with public health impact, evaluated through water consumption. In Portugal, eight reservoirs located in the South region were selected and study between 2000 and 2008. In Brazil, Três Marias reservoir (Minas Gerais Provence) and Tucuruí (Pará Provence) were selected and study in 2005 and 2006. Reservoirs were characterized in physical and chemical aspects, as well as phytoplankton community, through identification and counting of main present groups along study period. In bloom circumstances, liver toxins and neurotoxins producers like Aphanizomenon sp, Microcystis aeruginosa and Oscillatoria sp. were founded in Portuguese reservoirs. In Brazil, cyanobacteria genera involved in toxic bloom were Microcystis (> 350.000 cels/ml) and Cylindrospermopsis. This genera presence represents a potential risk for public health, and show the requirement to implement mitigation measures in all study reservoirs. These measures can be represented by water eutrophication control to avoid blooms, by appropriate treatments of water to human consumption, and public warnings or information to dose people in Portugal and Brazil that use these reservoirs to several activities.

Selecção do melhor descolorante para a eliminação da cor residual num efluente têxtil

Mestrado em Engenharia Química

The adjusted effect of maternal body mass index, energy and macronutrient intakes during pregnancy, and gestational weight gain on body composition of full-term neonates

Objective - To evaluate the effect of prepregnancy body mass index (BMI), energy and macronutrient intakes during pregnancy, and gestational weight gain (GWG) on the body composition of full-term appropriate-for-gestational age neonates. Study Design - This is a cross-sectional study of a systematically recruited convenience sample of mother-infant pairs. Food intake during pregnancy was assessed by food frequency questionnaire and its nutritional value by the Food Processor Plus (ESHA Research Inc, Salem, OR). Neonatal body composition was assessed both by anthropometry and air displacement plethysmography. Explanatory models for neonatal body composition were tested by multiple linear regression analysis. Results - A total of 100 mother-infant pairs were included. Prepregnancy overweight was positively associated with offspring weight, weight/length, BMI, and fat-free mass in the whole sample; in males, it was also positively associated with midarm circumference, ponderal index, and fat mass. Higher energy intake from carbohydrate was positively associated with midarm circumference and weight/length in the whole sample. Higher GWG was positively associated with weight, length, and midarm circumference in females. Conclusion - Positive adjusted associations were found between both prepregnancy BMI and energy intake from carbohydrate and offspring body size in the whole sample. Positive adjusted associations were also found between prepregnancy overweight and adiposity in males, and between GWG and body size in females.

Multi index model - uma abordagem para aplicação ao mercado accionista em Portugal

O mercado accionista, de uma forma global, tem-se revelado nos últimos tempos uma das principais fontes de incentivo ao mercado de valores mobiliários. O seu impacto junto do público em geral é enorme e a sua importância para as empresas é vital. Interessa, então, perceber como é que a teoria financeira tem obordado a avaliação e a compreensão do processo de formação de uma cotação. Desde os anos 50 até aos dias de hoje, interessa perceber como é que os diferentes autores têm tratado esta abordagem e quais os resultados deste confronto. Interessa sobretudo perceber o abordogem de Stephen Ross e a teoria do arbitragem. Na sequência desta obordagem e com o aparecimento do Multi Index Model, passou a ser possível extimar com maior precisão a evolução da cotação, na medida em que esta estaria dependente de um vasto conjunto de variavéis, que abragem uma vasta área de influência. O contributo de Ross é por isso decisivo. No final interessa reter a melhor técnica e teoria, que defende os interesses do investidor. Face o isto resta, então, saber qual a melhor técnica estatística para proceder a estes estudos empíricos.

Comorbidity adjustment index for the international classification of diseases, 10

OBJECTIVE: To develop a Charlson-like comorbidity index based on clinical conditions and weights of the original Charlson comorbidity index. METHODS: Clinical conditions and weights were adapted from the International Classification of Diseases, 10th revision and applied to a single hospital admission diagnosis. The study included 3,733 patients over 18 years of age who were admitted to a public general hospital in the city of Rio de Janeiro, southeast Brazil, between Jan 2001 and Jan 2003. The index distribution was analyzed by gender, type of admission, blood transfusion, intensive care unit admission, age and length of hospital stay. Two logistic regression models were developed to predict in-hospital mortality including: a) the aforementioned variables and the risk-adjustment index (full model); and b) the risk-adjustment index and patient's age (reduced model). RESULTS: Of all patients analyzed, 22.3% had risk scores >1, and their mortality rate was 4.5% (66.0% of them had scores >1). Except for gender and type of admission, all variables were retained in the logistic regression. The models including the developed risk index had an area under the receiver operating characteristic curve of 0.86 (full model), and 0.76 (reduced model). Each unit increase in the risk score was associated with nearly 50% increase in the odds of in-hospital death. CONCLUSIONS: The risk index developed was able to effectively discriminate the odds of in-hospital death which can be useful when limited information is available from hospital databases.

Body mass index for predicting hyperglycemia and serum lipid changes in Brazilian adolescents

OBJECTIVE: To determine the best cut-offs of body mass index for identifying alterations of blood lipids and glucose in adolescents. METHODS: A probabilistic sample including 577 adolescent students aged 12-19 years in 2003 (210 males and 367 females) from state public schools in the city of Niterói, Southeastern Brazil, was studied. The Receiver Operating Characteristic curve was used to identify the best age-adjusted BMI cut-off for predicting high levels of serum total cholesterol (>150mg/dL), LDL-C (>100mg/dL), serum triglycerides (>100mg/dL), plasma glucose (>100mg/dL) and low levels of HDL-C (< 45mg/dL). Four references were used to calculate sensitivity and specificity of BMI cut-offs: one Brazilian, one international and two American. RESULTS: The most prevalent metabolic alterations (>50%) were: high total cholesterol and low HDL-C. BMI predicted high levels of triglycerides in males, high LDL-C in females, and high total cholesterol and the occurrence of three or more metabolic alterations in both males and females (areas under the curve range: 0.59 to 0.67), with low sensitivity (57%-66%) and low specificity (58%-66%). The best BMI cut-offs for this sample (20.3 kg/m² to 21.0 kg/m²) were lower than those proposed in the references studied. CONCLUSIONS: Although BMI values lower than the International cut-offs were better predictor of some metabolic abnormalities in Brazilian adolescents, overall BMI is not a good predictor of these abnormalities in this population.

Estimate of DMFT index using teeth most affected by dental caries in twelve-year-old children

The objective of the study was to develop regression models to describe the epidemiological profile of dental caries in 12-year-old children in an area of low prevalence of caries. Two distinct random probabilistic samples of schoolchildren (n=1,763) attending public and private schools in Piracicaba, Southeastern Brazil, were studied. Regression models were estimated as a function of the most affected teeth using data collected in 2005 and were validated using a 2001 database. The mean (SD) DMFT index was 1.7 (2.08) in 2001 and the regression equations estimated a DMFT index of 1.67 (1.98), which corresponds to 98.2% of the DMFT index in 2001. The study provided detailed data on the caries profile in 12-year-old children by using an updated analytical approach. Regression models can be an accurate and feasible method that can provide valuable information for the planning and evaluation of oral health services.

Desenvolvimento do método de Índice de Qualidade ("QIM-Quality Index Method") para as lapas (Patella candei e Patella aspera) e estudo das suas condições de transporte

Dissertação de Mestrado, Estudos Integrados dos Oceanos, 15 de Março de 2016, Universidade dos Açores.