Tempo de voltar à terra

Texto publicado no Suplemento "Regresso à Terra" por ocasião do 94º Aniversário do Correio dos Açores.

Strawberries from integrated pest management and organic farming: phenolic composition and antioxidant properties

Consumer awareness, pesticide and fertilizer contaminations and environmental concerns have resulted in significant demand for organically grown farm produce. Consumption of berries has become popular among health-conscious consumers due to the high levels of valuable antioxidants, such as anthocyanins and other phenolic compounds. The present study evaluated the influence that organic farming (OF) and integrated pest management (IPM) practise exert on the total phenolic content in 22 strawberry samples from four varieties. Postharvest performance of OF and IPM strawberries grown in the same area in the centre of Portugal and harvested at the same maturity stage were compared. Chemical profiles (phenolic compounds) were determined with the aid of HPLC-DAD/MS. Total phenolic content was higher for OF strawberry extracts. This study showed that the main differences in bioactive phytochemicals between organically and IPM grown strawberries concerned their anthocyanin levels. Organically grown strawberries were significantly higher in antioxidant activity than were the IPM strawberries, as measured by DPPH and FRAP assays.

Pesticide residues in Portuguese strawberries grown in 2009–2010 using integrated pest management and organic farming

Pesticides are among the most widely used chemicals in the world. Because of the widespread use of agricultural chemicals in food production, people are exposed to low levels of pesticide residues through their diets. Scientists do not yet have a total understanding of the health effects of these pesticide residues. This work aims to determine differences in terms of pesticide residue content in Portuguese strawberries grown using different agriculture practices. The Quick, Easy, Cheap, Effective, Rugged, and Safe sample preparation method was conducted and shown to have good performance for multiclass pesticides extraction in strawberries. The screening of 25 pesticides residue was performed by gas chromatography–tandem mass spectrometry. In quantitative validation, acceptable performances were achieved with recoveries of 70–120 and <12 % residual standard deviation for 25 pesticides. Good linearity was obtained for all the target compounds, with highly satisfactory repeatability. The limits of detection were in the range of 0.1–28 μg/kg. The method was applied to analyze strawberry samples from organic and integrated pest management (IPM) practices harvested in 2009–2010. The results showed the presence of fludioxonil, bifenthrin, mepanipyrim, tolylfluanid, cyprodinil, tetraconazole, and malathion when using IPM below the maximum residue levels.

Cryptotermes brevis (Isoptera: Kalotermitidae) in the Azores : Lessons After 2 yr of Monitoring in the Archipelago

The dispersal flights of West Indian drywood termite, Cryptotermes brevis (Walker) (Isoptera: Kalotermitidae) were surveyed in the major cities of Azores. The sampling device used to estimate termite density consisted of a yellow adhesive trap (size 45 by 24 cm), placed with an artificial or natural light source in a dark attic environment. In addition, data from two other projects were used to improve the knowledge about the geographical distribution of the species. The level of infestation in the two main Azorean towns differed, with high levels in the houses of Angra do Heroísmo, whereas in Ponta Delgada, there are fewer houses with high levels of infestation. The infestation in Ponta Delgada shows a pattern of spreading from the center outward to the city's periphery, whereas in Angra do Heroísmo, there was a pattern of spreading outward from several foci. The heavy infestation observed in Angra do Heroísmo and the clear increase of infestation levels observed from 2010 to 2011 is a reason for concern and calls for an urgent application of an Integrated Pest Management (IPM) control strategy.

Organochlorine pesticide residues in strawberries from integrated pest management and organic farming

A rapid, specific, and sensitive method based on theQuick Easy Cheap Effective Rugged and Safe (QuEChERS) method and a cleanup using dispersive solid-phase extraction with MgSO4, PSA, and C18 sorbents has been developed for the routine analysis of 14 pesticides in strawberries. The analyses were performed by three different analytical methodologies: gas chromatography (GC) with electron capture detection (ECD), mass spectrometry (MS), and tandem mass spectrometry (MS/MS). The recoveries for all the pesticides studied were from 46 to 128%, with relative standard deviation of <15% in the concentration range of 0.005-0.250 mg/kg. The limit of detection (LOD) for all compoundsmetmaximumresidue limits (MRL) accepted in Portugal for organochlorine pesticides (OCP). A survey study of strawberries produced in Portugal in the years 2009-2010 obtained from organic farming (OF) and integrated pest management (IPM) was developed. Lindane and β-endosulfan were detected above the MRL in OF and IPM. Other OCP (aldrin, o,p0-DDT and their metabolites, and methoxychlor) were found below the MRL. The OCP residues detected decreased from 2009 to 2010. The QuEChERS method was successfully applied to the analysis of strawberry samples.

Comparison of Disposable Pipette Extraction and Dispersive Solid-Phase Extraction in the QuEChERS Method for Analysis of Pesticides in Strawberries

In this study, we sought to assess the applicability of GC–MS/MS for the identification and quantification of 36 pesticides in strawberry from integrated pest management (IPM) and organic farming (OF). Citrate versions of QuEChERS (quick, easy, cheap, effective, rugged and safe) using dispersive solid-phase extraction (d-SPE) and disposable pipette extraction (DPX) for cleanup were compared for pesticide extraction. For cleanup, a combination of MgSO4, primary secondary amine and C18 was used for both the versions. Significant differences were observed in recovery results between the two sample preparation versions (DPX and d-SPE). Overall, 86% of the pesticides achieved recoveries (three spiking levels 10, 50 and 200 µg/kg) in the range of 70–120%, with <13% RSD. The matrix effects were also evaluated in both the versions and in strawberries from different crop types. Although not evidencing significant differences between the two methodologies were observed, however, the DPX cleanup proved to be a faster technique and easy to execute. The results indicate that QuEChERS with d-SPE and DPX and GC–MS/MS analysis achieved reliable quantification and identification of 36 pesticide residues in strawberries from OF and IPM.

In vitro activity of antimicrobial combinations against multidrug-resistant Pseudomonas aeruginosa

Introduction Pseudomonas aeruginosa isolates related to nosocomial infections are often resistant to multiple antibacterial agents. In this study, antimicrobial combinations were evaluated to detect in vitro synergy against clinical isolates of P. aeruginosa. Methods Four clinical P. aeruginosa isolates were selected at random among other isolates from inpatients treated at the public University hospital in Ribeirão Preto, SP, Brazil. Two isolates were susceptible to imipenem (IPM-S) and several other antimicrobials, while the other two isolates were imipenem and multidrug resistant (IPM-R). The checkerboard method was used to assess the interactions between antimicrobials. Results Combinations of imipenem or other anti-Pseudomonas drugs with complementary antibiotics, such as aminoglycosides, fosfomycin and rifampin, reached synergy rates of 20.8%, 50%, 62.5% and 50% for the two IPM-S and two IPM-R Pseudomonas isolates, respectively. Imipenem, piperacillin-tazobactam and ceftazidime yielded a greater synergy rate than cefepime or ciprofloxacin. Synergist combinations were more commonly observed when the complementary drug was tobramycin (65%) or fosfomycin (57%). Conclusions Some antibacterial combinations led to significant reductions of the minimum inhibitory concentrations of both drugs, suggesting that they could be clinically applied to control infections caused by multidrug-resistant P. aeruginosa.

Melhoria na gestão de compras em uma indústria do Pólo Industrial de Manaus (PIM)

Dissertação de mestrado em Engenharia e Gestão Industrial

Valor prognóstico do índice de performance miocárdica no pós-operatório de cirurgia de revascularização miocárdica

OBJETIVO: Avaliar o valor preditivo do índice de performance miocárdica (IPM) para complicações cardiovasculares em pacientes de baixo risco no pós-operatório (PO) de cirurgia de revascularização miocárdica (CRM) no período de internação hospitalar. MÉTODOS: Foram estudados 80 pacientes submetidos a CRM com função ventricular esquerda adequada no pré-operatório, nos quais o IPM foi medido nas primeiras horas de pós-operatório. Os pacientes foram acompanhados até a alta hospitalar. A análise estatística incluiu teste qui-quadrado de Pearson, teste t de Student e teste de Mann-Whitney, além do cálculo do risco relativo, com intervalos de confiança de 95%, e das propriedades de sensibilidade e especificidade do índice, com elaboração de curva ROC. RESULTADOS: Os dados foram avaliados por dois observadores independentes, cegos aos dados clínicos, com variabilidade intra e interobservador não significativa. Encontrou-se IPM=0,43 como ponto de corte, considerando-se acima de 0,43 os pacientes com maior probabilidade de eventos no pós-operatório. Os eventos relevantes para análise foram IAM (RR 0,87; IC 0,21 - 3,65); fibrilação atrial (RR 0,65; IC 0,24 - 1,76); outras arritmias (RR 1,51; IC 0,36 - 6,33) e disfunção VE (RR 1,74; IC 0,31 - 9,88), não havendo associação entre pacientes com IPM>0,43 e a ocorrência destes eventos. O tempo de internação hospitalar foi similar, entre os grupos (p=0,999). CONCLUSÃO: Não houve associação do IPM com complicações cardiovasculares e maior tempo de internação neste grupo de pacientes, podendo-se considerar esse índice inadequado como método preditivo isolado.

Papel do ecocardiograma na avaliação ventricular do coração transplantado versus rejeição cardíaca

FUNDAMENTO: O Transplante Cardíaco (TC) é uma alternativa para os indivíduos com doença cardíaca terminal. Na evolução pós-transplante, a ocorrência de episódios de Rejeição Cardíaca (RC) é evento frequente que aumenta a morbimortalidade, sendo necessário o emprego de exame não invasivo com boa acurácia para seu diagnóstico, pois a Biópsia Endomiocárdica (BEM) não é um procedimento isento de complicações. OBJETIVO: Comparar parâmetros obtidos com o princípio Doppler, entre os pacientes transplantados com RC (TX1) e os pacientes transplantados sem rejeição (TX0); utilizando como referência o Grupo Controle (GC) e observando o comportamento da função sistodiastólica ventricular esquerda expressa por meio do Índice de Performance Miocárdica (IPM). MÉTODOS: Foram realizados ecocardiogramas transtorácicos no período de janeiro de 2006 a janeiro de 2008, para a avaliação prospectiva de 47 pacientes, subdivididos em GC (36,2%), TX0 (38,3%) e TX1 (25,5%), comparando-se o IPM entre eles. Para a análise dos dados foram realizados os testes exato de Fisher e o não paramétrico de Kruskal-Wallis, ambos com nível de significância de 5%. RESULTADOS: Os grupos não diferiram em relação a idade, peso, altura e superfície corpórea. Quando comparado ao GC, TX0 e TX1 apresentaram alteração da função sistodiastólica ventricular esquerda, expressa como aumento do IPM, que foi mais intenso no TX1 [0,38 (0,29 - 0,44) X 0,47 (0,43 - 0,56) X 0,58 (0,52 - 0,74) p < 0,001]. CONCLUSÃO: O ecocardiograma mostrou-se como exame de boa acurácia na detecção das alterações da função sistodiastólica do coração transplantado; entretanto, não foi confiável como método substituto da BEM para o diagnóstico seguro de RC.

Determinação e comparação dos valôres Mi, A, Y e S, em dois tipos de solo do est. de S. Paulo

No presente trabalho, determinou-se e comparou-se os valores Mi de BARBIER et al., 1954, SCHEFFER e ULRICH, 1958, A de FRIED e DEAN, 1952 Y de LARSEN, 1952, e S de SOKOLOV, 1958, em dois tipos de solo do Estado de São Paulo: terra roxa legítima e um solo arenoso do campo da Secção Técnica de Química Agrícola da Escola Superior de Agricultura "Luiz de Queiroz". Aplicou-se 23,58 mg de fósforo, por vaso, na forma de superfosfato simples, contendo fósforo radioativo com uma atividade de 120.736 ipm; na forma de solução, aplicou-se também 200 mg de NH4N0(3) e 100 mg de KC1. Misturou-se bem para que houvesse homogenização a mais perfeita possível. Depois plantou-se 25 sementes de trigo, variedade 1146BH, deixando-se apenas 16 plantas após o desbaste. Procedeu-se àcolheita 55 dias após o plantio. Tanto a parte aérea como as raízes foram sêcas em estufa a 70-80°C. Sôbre o material triturado, digerido e diluído, retirou-se partes alíquotas para a determinação do P81 e do P32. Os valores obtidos para os dois tipos de solos foram os seguintes: mg de P por 1,5 kg de solo Valores Terra roxa legítima Solo arenoso Mi 177,96 92,62 A 177,55 92,71 Y 178,97 92,98 S 173,42 64,75 A análise estatística não revelou diferença significativa entre os valores Mi, A e Y, mas sim dêstes para o valor S. Quanto a este último valor, pode-se dizer que quanto mais rico em fósforo fôr o solo e quanto menor fôr o teor dêste elemento na semente, quanto mais êle deverá se aproximar dos valores Mi, A e Y.

Efeito do tipo de substrato para pupação na dispersão larval pós-alimentar de Chrysomya albiceps (Diptera, Calliphoridae)

As moscas-varejeiras utilizam substratos discretos e efêmeros para posturas dos ovos e para alimentação das larvas. Após a exaustão de recursos, as larvas começam a procurar por um sítio de pupação no habitat ou por mais fonte de alimento adicional (dispersão larval pós-alimentar). No entanto, o tipo de substrato de dispersão pode afetar este processo; assim, procurou-se avaliar o comportamento de dispersão de Chrysomya albiceps (Wiedemann 1819) por meio da localização das pupas em arenas circulares preenchidas com vermiculita, comparando-se com outros estudos feitos em serragem. As arenas foram dividas em 72 setores iguais a partir do centro de dispersão para facilitar a localização das pupas no substrato. A massa, a distância de dispersão do centro de arena, e a profundidade de cada pupa foram determinadas e verificou-se a relação entre peso, profundidade e distância do centro de dispersão. Pôde-se constatar que as larvas com menor massa foram as que percorreram maior distância do centro de dispersão, como também foi observado em estudos anteriores que empregaram outros substratos. O sítio de pupação da maioria dos indivíduos foi entre 2 e 8 cm de profundidade (média 4,96±2,97 cm). Tal estudo do processo de dispersão pode ser útil na estimativa do intervalo pós-morte (IPM) para corpos humanos em investigações médico-criminais.

Economic threshold levels for the velvetbean caterpillar on soybeans in Brazil: the social and the private perspectives

Pest Control is treated as a economic problem. The social and the private perspectives differ due to the consideration of the environmental and social impacts as well as technical aspects such as resistance, resurgence and secondary pests. A mathematical model is developed to determine and compare the social and the private optimum control strategies (which define the Economic Thereshold Levels) for the velvetbean caterpillar on soybeans in Brazil. The crop/pest system incorporates effects of predators and parasites, the soybean natural capacity to compensate for injury and the pesticide effects on both pests and its natural enemies; in the social case, the environmental and social impacts and the effects of pest resistance to the pesticide are incorporated. Consideration of density dependence, weather effects, randomnes of pest attack and risk aversion are discussed. The results can be compared with current control practices and IPM programme recomendations.

Oral insecticidal activity of root colonizing Pseudomonas fluorescens CHA0: a biocontrol agent with potential to control plant pests and diseases

The application of microbial biocontrol agents for the control of fungal plant diseases and plant insect pests is a promising approach in the development of environmentally benign pest management strategies. The ideal biocontrol organism would be a bacterium or a fungus with activity against both, insect pests and fungal pathogens. Here we demonstrate the oral insecticidal activity of the root colonizing Pseudomonas fluorescens CHA0, which is so far known for its capacity to efficiently suppress fungal plant pathogens. Feeding assays with CHA0-sprayed leaves showed that this strain displays oral insecticidal activity and is able to efficiently kill larvae of three important insect pests. We further show data indicating that the Fit insect toxin produced by CHA0 and also metabolites controlled by the global regulator GacA contribute to oral insect toxicity.

Evaluation of the synergistic potential of vancomycin combined with other antimicrobial agents against methicillin-resistant Staphylococcus aureus and coagulase-negative Staphylococcus spp strains

Methicillin-resistant Staphylococcus aureus (MRSA) and coagulase-negative Staphylococcus spp (CNS) are the most common pathogens that cause serious long term infections in patients. Despite the existence of new antimicrobial agents, such as linezolid, vancomycin (VAN) remains the standard therapy for the treatment of infections caused by these multidrug-resistant strains. However, the use of VAN has been associated with a high frequency of therapeutic failures in some clinical scenarios, mainly with decreasing concentration of VAN. This work aims to evaluate the synergic potential of VAN plus sulfamethoxazole/trimethoprim (SXT), VAN plus rifampin (RIF) and VAN plus imipenem (IPM) in sub-minimum inhibitory concentrations against 22 clinical strains of MRSA and CNS. The checkerboard method showed synergism of VAN/RIF and VAN/SXT against two and three of the 22 strains, respectively. The combination of VAN with IPM showed synergistic effects against 21 out of 22 strains by the E-test method. Four strains were analyzed by the time-kill curve method and synergistic activity was observed with VAN/SXT, VAN/RIF and especially VAN/IPM in sub-inhibitory concentrations. It would be interesting to determine if synergy occurs in vivo. Evidence of in vivo synergy could lead to a reduction of the standard VAN dosage or treatment time.