Browsing by Author "Machado, J."
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- Analysis of the use of microcystin-contaminated water in the growth and nutritional quality of the root-vegetable, Daucus carotaPublication . Machado, J.; Azevedo, J.; Freitas, Marisa; Pinto, Edgar; Almeida, A.; Vasconcelos, V.; Campos, A.Toxic cyanobacterial blooms are often observed in freshwaters and may reflect the increased eutrophication of these environments and alterations in climate. Cyanotoxins, such as microcystins (MCs), are an effective threat to many life forms, ranging from plants to humans. Despite the research conducted to date on cyanotoxins, the risks associated to the use of contaminated water in agriculture require further elucidation. To tackle this aim, a research was conducted with the root-vegetable Daucus carota. The specific aims of this work were the following: (i) to evaluate the effects of MC-LR on the plant growth and photosynthesis; (ii) to evaluate the nutritional quality of carrot roots; and (iii) to measure bioaccumulation. To this purpose, young carrots were grown in soil during 1 month in natural conditions and exposed to Mycrocystis aeruginosa aqueous extracts containing environmentally realistic concentrations of MC-LR (10 and 50 MC-LR μg/L). The results showed that MC-LR may decrease root growth after 28 days of exposure to 50 μg/L and increase photosynthetic efficiency. We also observed changes in mineral and vitamin content in carrots as a result of the exposure to contaminated water. Moreover, MC-LR was detected in carrot roots by ELISA at very low concentration 5.23 ± 0.47 ng MC eq./g FW. The soil retained 52.7 % of the toxin potentially available for plants. This result could be attributed to MC-LR adsorption by soil particles or due to microbial degradation of the toxin. We conclude that the prolonged use of MC-LR-contaminated water may affect crop growth, alter the nutritional value of vegetable products, and potentiate contamination.
- Educar para a saúde laboral: perceção da qualidade de vida em relação a variáveis sociodemográficas, condições de saúde e de trabalho em trabalhadores de escritórioPublication . Moreira, S.; Miranda, A.; Lima, C.; Gonçalves, C.; Mesquita, Cristina; Lopes, Sofia; Machado, J.; Santos, Paula ClaraOs trabalhadores de escritório permanecem em posições estacionárias durante longos períodos e estão sujeitos a elevadas cargas laborais que podem interferir com a Qualidade de Vida, em interação com caraterísticas do trabalhador (como personalidade, autonomia, competência e empenho no trabalho). A Qualidade de Vida é um conceito multidimensional influenciado por fatores sociodemográficos, de saúde e trabalho, que se tornou um desafio de Saúde Ocupacional, pela preocupação crescente das organizações que atuam a esse nível.
- Effects of microcystin-LR and cylindrospermopsin on plant-soil systems: A review of their relevance for agricultural plant quality and public healthPublication . Machado, J.; Campos, A.; Vasconcelos, V.; Freitas, MarisaToxic cyanobacterial blooms are recognized as an emerging environmental threat worldwide. Although microcystin-LR is the most frequently documented cyanotoxin, studies on cylindrospermopsin have been increasing due to the invasive nature of cylindrospermopsin-producing cyanobacteria. The number of studies regarding the effects of cyanotoxins on agricultural plants has increased in recent years, and it has been suggested that the presence of microcystin-LR and cylindrospermopsin in irrigation water may cause toxic effects in edible plants. The uptake of these cyanotoxins by agricultural plants has been shown to induce morphological and physiological changes that lead to a potential loss of productivity. There is also evidence that edible terrestrial plants can bioaccumulate cyanotoxins in their tissues in a concentration dependent-manner. Moreover, the number of consecutive cycles of watering and planting in addition to the potential persistence of microcystin-LR and cylindrospermopsin in the environment are likely to result in groundwater contamination. The use of cyanotoxin-contaminated water for agricultural purposes may therefore represent a threat to both food security and food safety. However, the deleterious effects of cyanotoxins on agricultural plants and public health seem to be dependent on the concentrations studied, which in most cases are non-environmentally relevant. Interestingly, at ecologically relevant concentrations, the productivity and nutritional quality of some agricultural plants seem not to be impaired and may even be enhanced. However, studies assessing if the potential tolerance of agricultural plants to these concentrations can result in cyanotoxin and allergen accumulation in the edible tissues are lacking. This review combines the most current information available regarding this topic with a realistic assessment of the impact of cyanobacterial toxins on agricultural plants, groundwater quality and public health.
- Effects of the irrigation with Microcystin contaminated water on the quality of carrots (Daucus carota)Publication . Machado, J.; Azevedo, J.; Freitas, Marisa; Pinto, Edgar; Vasconcelos, V.; Campos, A.Cyanobacteria blooms are often found in freshwaters and may reflect the increased eutrophication of these environments. Microcystin-LR (MC-LR), mainly produced by Microcystis aeruginosa, is the most documented and studied cyanotoxin causing serious problems to human health. Contaminated waters are commonly used for agriculture purposes and may represent a risk to food safety and crop’s quality. The plant root system is usually more exposed via soil irrigation, and therefore, rootvegetables are more predisposed to contamination. Is important to evaluate the possible negative effects of the use of water containing MC in the physiology and quality of carrots (Daucus carota) due to its importance for human nourishment and economy.
- Impact of microcystin contaminated water on quality of carrots (Daucuscarota)Publication . Machado, J.; Azevedo, J.; Freitas, Marisa; Pinto, Edgar; Vasconcelos, Vitor; Campos, AlexandreCyanobacteria blooms are often found in freshwaters and may reflect the increased eutrophication of these environments and because of this many water resources worldwide may have a limited utilization. The presence of these microorganisms may pose a serious threat to water quality because many of them produce a large diversity of toxins that can be harmful to human health (Figueiredo et a l., 2004). On the other hand contaminated waters used to agricultural purposes may pose additional concerns to food safety. The absorption of toxins by plants may induce morphological and physiological changes that can lead to a loss of productivity as well as toxin bioaccumulation in edible tissues. However, the impact of cyanotoxins on plants and its ability to enter the food chain via this pathway is not fully understood (Kitleret al ., 2012). Microcystin (MC) is the cyanotoxin most frequently present in eutrophic freshwaters causing serious problems to human health, being the liver the main target. These toxins are potent and specific inhibitors of protein phosphatases PP1 and PP2Ain both animals and higher plants (Figueiredo et al., 2004). It is known that MC affect a number of physiological processes in plants (Corbel et al ., 2013). The plant root system is usually more exposed, via soil irrigation, and therefore root-vegetables more prone to contamination. Carrots (Daucuscarota) are root-vegetables with great importance for human nourishment and economy, with extensive use all over the world (Singh et al ., 2012).
- Kinect system in home-based cardiovascular rehabilitationPublication . Vieira, Ágata; Gabriel, J.; Melo, Cristina; Machado, J.Cardiovascular diseases lead to a high consumption of financial resources. An important part of the recovery process is the cardiovascular rehabilitation. This study aimed to present a new cardiovascular rehabilitation system to 11 outpatients with coronary artery disease from a Hospital in Porto, Portugal, later collecting their opinions. This system is based on a virtual reality game system, using the Kinect sensor while performing an exercise protocol which is integrated in a home-based cardiovascular rehabilitation programme, with a duration of 6 months and at the maintenance phase. The participants responded to a questionnaire asking for their opinion about the system. The results demonstrated that 91% of the participants (n = 10) enjoyed the artwork, while 100% (n = 11) agreed on the importance and usefulness of the automatic counting of the number of repetitions, moreover 64% (n = 7) reported motivation to continue performing the programme after the end of the study, and 100% (n = 11) recognized Kinect as an instrument with potential to be an asset in cardiovascular rehabilitation. Criticisms included limitations in motion capture and gesture recognition, 91% (n = 10), and the lack of home space, 27% (n = 3). According to the participants' opinions, the Kinect has the potential to be used in cardiovascular rehabilitation; however, several technical details require improvement, particularly regarding the motion capture and gesture recognition.