Epidemiology of Disappearing Plasmodium vivax Malaria: A Case Study in Rural Amazonia

Background: New frontier settlements across the Amazon Basin pose a major challenge for malaria elimination in Brazil. Here we describe the epidemiology of malaria during the early phases of occupation of farming settlements in Remansinho area, Brazilian Amazonia. We examine the relative contribution of low-density and asymptomatic parasitemias to the overall Plasmodium vivax burden over a period of declining transmission and discuss potential hurdles for malaria elimination in Remansinho and similar settings. Methods: Eight community-wide cross-sectional surveys, involving 584 subjects, were carried out in Remansinho over 3 years and complemented by active and passive surveillance of febrile illnesses between the surveys. We used quantitative PCR to detect low-density asexual parasitemias and gametocytemias missed by conventional microscopy. Mixed-effects multiple logistic regression models were used to characterize independent risk factors for P. vivax infection and disease. Principal Findings/Conclusions P. vivax prevalence decreased from 23.8% (March–April 2010) to 3.0% (April–May 2013), with no P. falciparum infections diagnosed after March–April 2011. Although migrants from malaria-free areas were at increased risk of malaria, their odds of having P. vivax infection and disease decreased by 2–3% with each year of residence in Amazonia. Several findings indicate that low-density and asymptomatic P. vivax parasitemias may complicate residual malaria elimination in Remansinho: (a) the proportion of subpatent infections (i.e. missed by microscopy) increased from 43.8% to 73.1% as P. vivax transmission declined; (b) most (56.6%) P. vivax infections were asymptomatic and 32.8% of them were both subpatent and asymptomatic; (c) asymptomatic parasite carriers accounted for 54.4% of the total P. vivax biomass in the host population; (d) over 90% subpatent and asymptomatic P. vivax had PCR-detectable gametocytemias; and (e) few (17.0%) asymptomatic and subpatent P. vivax infections that were left untreated progressed to clinical disease over 6 weeks of follow-up and became detectable by routine malaria surveillance

Inibidores de etileno na pós-colheita de Lisianthus

Devido à expansão da floricultura brasileira nas últimas duas décadas, a crescente demanda deste setor por produtos de alta qualidade e durabilidade e à carência de estudos relacionados à fisiologia pós-colheita de flores, esse trabalho teve como objetivo estudar a durabilidade pós-colheita de hastes de lisianthus (Eustoma grandiflorum) submetidas ao tratamento com inibidores de etileno (1-Metilciclopropeno -1-MCP e Ácido Salicílico - SA) e diferentes temperaturas de armazenamentos (ambiente a 24 ± 2°C e pré-exposição à câmara fria a 9 ± 2°C por 24 horas). A longevidade foi acompanhada a partir de análises não destrutivas (escala de notas, perda de massa fresca e teor de água absorvido pela haste) e destrutivas (teor de carboidratos solúveis totais, fenóis e proteínas solúveis, e atividade das enzimas peroxidase – POD e polifenoloxidase – PPO). A aplicação de 1000 mg L-1 de ácido salicílico mostrou-se ineficiente, pois as hastes apresentaram sintomas de fitotoxidade, elevada taxa de inclinação do pedúnculo e amarelecimento de pétalas, e redução na turgescência e longevidade das hastes tanto em temperatura ambiente quanto na pré-exposição a câmara fria, além de propiciarem o surgimento de patógenos. A associação entre 1-MCP e câmara fria foi um bom tratamento para aumentar a durabilidade das hastes, que apresentaram melhores características de inclinação do pedúnculo e turgescência. Os teores de carboidratos presente nas hastes sofreram redução durante todo o período experimental independente dos tratamentos pós-colheita e da temperatura de armazenamento, assim como a absorção de água pelas mesmas. Durante o período de avaliações, a atividade enzimática aumentou com a senescência do material, relação direta com a concentração de fenóis que se acumulam nos tecido lesionados...Due to the expansion of the Brazilian floriculture in the last two decades, the growing demand in this sector for high quality products and durability and the lack of studies on postharvest physiology of flowers, this work aimed to study the postharvest longevity stems of lisianthus (Eustoma grandiflorum) subjected to treatment with inhibitors of ethylene (1-methylcyclopropene 1-MCP and Salicylic Acid - SA) and different storage temperatures (ambient to 24 ± 2° C and pre-exposure chamber at 9 ± 2° C for 24 hours). Longevity was accompanied from non-destructive analysis (grading scale, weight loss and water content absorbed by the stem) and destructive (total soluble carbohydrates, phenols and soluble proteins, and activity of peroxidase - POD and polyphenoloxidase - PPO). The application of 1000 mg L-1 of salicylic acid proved to be inefficient, because the rods showed symptoms of phytotoxicity high rate of bent neck and yellowing of petals, and reduction in swelling and longevity of the rods both in room temperature and in pre-exposure to cold chamber, in addition to propitiate the appearance of pathogens. The association between 1-MCP and cold chamber was a good treatment to increase the durability of... (Complete abstract click electronic access below

Epidermis topographic characterization of leafy vegetables and ozone gas mixture in lettuce quality

Orientador: Antonio Carlos de Oliveira FerrazTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia AgrícolaResumo: Tendo em vista o aumento do consumo mundial por produtos frescos e a grande preocupação com a qualidade dos mesmos por apresentarem baixa resistência ao manuseio e transporte, alta perecibilidade após a colheita e suscetibilidade à contaminação microbiológica, estudos buscando novas tecnologias para reduzir as perdas e manter suas características organolépticas são de fundamental importância. Desta forma, esse trabalho teve como objetivos medir o grau de rugosidade da epiderme de hortaliças folhosas e investigar seu potencial para hospedar diferentes espécies de micro-organismos, assim como avaliar o desempenho do ozônio, em mistura gasosa, na redução da carga microbiológica e manutenção da qualidade de alfaces. Para a caracterização da rugosidade foram utilizadas folhas de alface americana e crespa, almeirão, couve e rúcula. As medidas foram feitas utilizando-se de microscopia eletrônica de varredura e perfilometria óptica. Para investigar a eficiência do uso de ozônio como agente sanitizante e na manutenção das características de qualidade de hortaliças foram utilizadas folhas de alface americana e crespa. Avaliou-se o efeito da aplicação de mistura gasosa de ozônio pela aparência das folhas, análises físico-químicas, bioquímicas e microbiológicas. As folhas foram expostas a um escoamento de ozônio em três diferentes concentrações: 1,74; 4,98 e 8,34 ppm, aplicadas nos tempos de 10, 30 e 50 segundos, de forma que pelo menos dois tratamentos atingissem a concentração final de 0,06, 0,10 e 0,30 ppm no interior da câmara. A superfície das hortaliças folhosas estudadas mostraram potencial de abrigar diversas espécies de micro-organismos, devido à rugosidade, estruturas e espaços intercelulares. O almeirão foi o que apresentou o maior potencial para alojamento de micro-organismos, pois apresentou o maior coeficiente de rugosidade. Com a aplicação da mistura gasosa de ozônio ouve redução significativa nos níveis de bactérias aeróbias mesófilas e psicrotróficas, bolores e leveduras presentes na superfície das folhas. Mesmo as concentrações consideradas baixas, 0,06 e 0,10 ppm, a aplicação foi eficaz na redução da maioria dos micro-organismos estudados mantendo as características de qualidade das folhas de alface. Observou-se que a variação da atividade das enzimas peroxidase e polifenoloxidase mostrou-se útil na avaliação da senescência de alface, indicando que a qualidade foi preservada até o 3º dia de armazenamento, após a aplicação de ozônio. Concluiu-se que diferentes folhosas apresentam potenciais distintos para alojar micro-organismos em sua superfície e que o uso de mistura gasosa de ozônio é eficaz para a redução da carga microbiológica em alface preservando-se a qualidadeAbstract: In view of the world increase consumption of fresh produce and a great concern for their quality due to their low resistance to handling and transportation, high postharvest perishability and susceptibility to microbiological contamination, investigations on new reducing loss technology and keeping organoleptic characteristics are of fundamental importance. In this way, the main objective of this work was to measure the degree of epidermis roughness of the of leafy vegetables and to investigate their potential to host different species of microorganisms, as well as to evaluate the ozone performance, in gas mixture, in reducing microbiological load while keeping quality of lettuce leaves. To characterize the topography of the surface, leaves of iceberg and green-leaf lettuce, wild chicory, collards and arugula were used. Measurements were performed using scanning electron microscopy and optical profilometry. For the study of the effictiveness of the use of ozone mixture as a sanitizing agent and in keeping quality leaves of iceberg and green-leaf lettuces were used. The effect of the exposure to the gaseous ozone mixture was evaluated using leaf appearance, physical-chemical, biochemical and microbiological indexes. The leaves were exposed to flows of the gaseous mixture with three different concentrations of ozone, 1.74; 4.98 and 8.34 ppm, associated with exposure times of 10, 30 and 50 seconds so that at least two treatments reached the same final concentration of 0.06, 0.10 and 0.30 ppm in the chamber. The surface of the leafy vegetables studied showed potential to shelter several species of microorganisms, due to the roughness, structures and intercellular spaces. Wild chicory leaves showed the greatest potential to host microorganisms due to their higher roughness coefficient. The exposure to the gaseous ozone mixture significantly reduced the levels of aerobic mesophilic and psychrotrophic bacteria, molds and yeasts present on the leaves surface. Even for low concentrations, 0.06 and 0.10 ppm, it was was effective to reduce most of the microorganisms studied while keeping the quality characteristics of lettuce leaves. It was observed that the activity variation of peroxidase and polyphenoloxidase enzymes can be applied as an index in the lettuce senescence evaluation since it acts as a biochemical marker for the product quality. In this investigation, it pointed out that quality was maintained up to 3 days of storage after the application of ozone. It was concluded that different leaf vegetables have distinct micorganism lodging potential ant that the use of a ozone gaseous mixture is effective in reducing the microbiological load while keeping lettuce qualityDoutoradoTecnologia Pós-ColheitaDoutora em Engenharia163253/2013-7CNP

Carbohydrate reserves on postharvest of lisianthus cut flowers

Floriculture industry demands for products with high quality and durability; however, there is a lack of studies related to the postharvest physiology of cut flowers. We aimed to study phenolic contents of lisianthus (Eustoma grandiflorum) stems treated with ethylene inhibitors (1-Methylcyclopropene - 1-MCP and Salicylic Acid - SA) and different storage temperatures (room at 24 ± 2 °C and pre-exposure to the cold chamber at 9 ± 2 °C for 24 hours) during the post-harvest. Total soluble carbohydrate contents decreased during the experimentation, characterizing the consumption of the reserves during lisianthus post-harvest. The 1-MCP treatment slowed the decrease of total soluble carbohydrate contents. SA treatment had the lowest total soluble carbohydrate contents in both storage temperature

Temperature and substrate for the germination test of physic nut seeds

Official rules for seed analysis don't establish criteria to execute germination tests for all species. This way, the aim of this research was to determinate the substrate, temperature and counting time for the germination test of physic nut seeds. For the germination test, four replications of 20 seeds were used, evaluating daily the normal seedlings until the end of germination. Initially, the substrates with sowing in vermiculite, were evaluated in rolled paper towels, in sand and in soil using alternating temperature of 20-30 degrees C. The most favorable substrates for germination were evaluated with another stage, using constant temperatures of 25, 30 and 35 degrees C and alternating ones, of 15-35 degrees C, 20-35 degrees C and 20-30 degrees C. One concluded that the germination test of physic nut seeds must be performed with the alternating temperature of 20-30 degrees C in sand or paper towel and with final counting 10 days after sowing

Quality in anthurium andraeanum after postharvest BAP treatment

To ensure the ongoing quality of anthurium inflorescence it is necessary to use postharvest treatments aimed at extending the vase life and delaying senescence. Thus, the objective of this study was to assess the effect of postharvest spray application of 6-benzylaminopurine (BAP) in anthurium quality and sugar levels. Two experiments were done, one where inflorescences were sprayed 0, 100 and 200 mg L-1 of BAP and kept under 23±1°C and relative humidity of 65±5% for evaluations, and in the second experiment BAP concentrations were reduced to 0, 50 and 100 mg L-1 and inflorescences were cold stored for 2 days at 13±1°C and then transferred to the same evaluation conditions from the first experiment. Quality assessments were performed according to Paull (1982) for spathe loss of gloss and blueing and spadix necrosis along with stem weighting for fresh weight (FW) variation every two days. In the first experiment FW loss was significantly lower from the 14th until 26th day after harvest. Anthurium sprayed with 100 and 200 mg L-1 showed significantly less fresh weight loss when compared to control stems and in the second experiment 50 and 100 mg L-1 did not reduce fresh weight loss. Means of scores from quality analysis, blueing and loss of gloss of spathes and spadix necrosis, were significantly lower in BAP sprayed anthurium (100 and 200 mg L-1) than in control flowers and by lowering BAP spray concentration and cold storing stems for two days this positive effect was only observed for spadix necrosis and not observed for spathe parameters

Lisianthus vase life after 1-methylcyclopropene and salicylic acid postharvest treatment

This study evaluated the effects of application of 0.5 µl L-1 1-methyl-cyclopropene (1-MCP), 1000 mg L-1 salicylic acid (SA) and the interaction between the two products at room temperature and pre-exposure at 9±2°C for 24 h in maintaining postharvest quality of lisianthus flowers. After applying the treatment, the flowers were kept in jars with water, stored at 24±2°C. The SA treatments proved ineffective, presenting symptoms of phytotoxicity, with high rate of bent neck and yellowing of petals, both at room temperature and in cold storage, and propitiate the emergence of pathogens. The association between 1-MCP in pre-exposure to 9±2°C for 24 h increased the durability of the stems in six days compared to the control treatment, with less symptoms of bent neck and swelling of stems

Soluble proteins and polyphenoloxidase activity in bud flowers, flowers and leaves of cold stored lisianthus

This study evaluated the activity of the enzyme polyphenol oxidase (PPO) and the content of soluble protein present in lisianthus bud flowers, flowers and leaves in room temperature (24±2°C) and pre-exposure cold chamber at 9±2°C for 24 h, in order to examine a possible correlation between these parameters and postharvest longevity of lisianthus flowers. After treatments, flowers were kept in pots with water, stored at room temperature and evaluated every three days until the end of their decorative life for biochemical analyzes. During the experimental period the enzymatic activity increased with the aging of the material, directly related to the high concentration of phenolics that were accumulated in injured tissue, providing browning, while soluble protein content slightly decreased. Thus, PPO enzyme activity can be applied for plant senescence evaluation, acting as a biochemical marker for product visual quality

Bioactive films of arrowroot starch and blackberry pulp : physical, mechanical and barrier properties and stability to pH and sterilization

The influence of the incorporation of blackberry pulp on properties of arrowroot starch films has been studied. The blackberry pulp transferred bioactive compounds, antioxidant capacity and color to arrowroot starch films. Increasing the concentration of blackberry pulp (from 0 to 40%, mass/mass of dry starch) in the film resulted in increased thickness (from 0.065 to 0.133 mm), increased elongation (from 3.18 to 13.59%), decreased tensile strength (from 22.71 to 3.97 MPa), increased water vapor permeability (from 3.62 to 4.60 g.mm/m(2).day.kPa) and solubility in water (from 14.18 to 25.46%). The films were stable to different media, maintaining the same initial diameter dimensions after immersion in acidic, neutral and alkaline solutions, but their color intensity was reduced, probably due to the release of anthocyanins to the solutions. The films with blackberry pulp presented darkness after sterilization process275417425COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPES01-P-3712/201