141 research outputs found

    Fish under pressure: examining behavioural responses of Iberian barbel under simulated hydropeaking with instream structures

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    Research ArticleHydropeaking is the rapid change in the water flow downstream of a hydropower plant, driven by changes in daily electricity demand. These fluctuations may produce negative effects in freshwater fish. To minimize these impacts, previous studies have proposed habitat enhancement structures as potential mitigation measures for salmonids. However, the recommendation of these mitigation measures for cyprinids remains scarce and their effects unknown. In this study, the effects of potential habitat mitigation structures under simulated hydropeaking and base-flow conditions are examined for Iberian barbel (Luciobarbus bocagei) in an indoor flume. Solid triangular pyramids and v-shaped structures were evaluated as potential flow-refuging areas and compared with a configuration without structures. A novel, interdisciplinary approach is applied to investigate individual and group responses to rapidly changing flows, by assessing physiological (glucose and lactate), movement behaviour (structure use, sprints and drifts) and the pressure distribution using a fish-inspired artificial lateral line flow sensor. The major findings of this study are four-fold: 1) Under hydropeaking conditions, the v-shaped structures triggered a lactate response and stimulated individual structure use, whereas solid structures did not elicit physiological adjustments and favoured individual and group structure use. Overall, both solid structures and their absence stimulated sprints and drifts. 2) The hydrodynamic conditions created in hydropeaking did not always reflect increased physiological responses or swimming activity. 3) Each event-structure combination resulted in unique hydrodynamic conditions which were reflected in the different fish responses. 4) The most relevant flow variable measured was the pressure asymmetry, which is caused by the vortex size and shedding frequency of the structures. Considering the non-uniform nature of hydropeaking events, and the observation that the fish responded differently to specific flow event-structure combinations, a diverse set of instream structures should be considered for habitat-based hydropeaking mitigation measures for Iberian barbelinfo:eu-repo/semantics/publishedVersio

    Preliminary study on the effect of fermented cheese whey on Listeria monocytogenes, Escherichia coli O157:H7 and Salmonella Goldcoast populations inoculated onto fresh organic lettuce

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    Cheese whey fermented by an industrial starter consortium of lactic acid bacteria was evaluated for its antibacterial capacity to control a selection of pathogenic bacteria. For their relevance on outbreak reports related to vegetable consumption, this selection included Listeria monocytogenes, serotype 4b, Escherichia coli O157:H7, and Salmonella Goldcoast. Organically grown lettuce was inoculated with an inoculum level of *107 colonyforming unit (CFU)/mL and was left for about 1 h in a safety cabinet before washing with a perceptual solution of 75:25 (v/v) fermented whey in water, for 1 and 10 min. Cells of pathogens recovered were then counted and their number compared with that obtained for a similar treatment, but using a chlorine solution at 110 ppm. Results show that both treatments, either with chlorine or fermented whey, were able to significantly reduce ( p < 0.05) the number of bacteria, in a range of 1.15–2.00 and 1.59–2.34 CFU/g, respectively, regarding the bacteria tested. Results suggest that the use of fermented whey may be as effective as the solution of chlorine used in industrial processes in reducing the pathogens under study (best efficacy shown for Salmonella), with the advantage of avoiding health risks arising from the formation of carcinogenic toxic chlorine derinfo:eu-repo/semantics/publishedVersio

    Parapharyngeal space tumors: a 10 year experience of IPO-LFG

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    Introdução: As neoplasias do espaço parafaríngeo são raras, representando apenas 0,5% dos tumores da cabeça e pescoço. A maioria são benignas, mas uma ampla variedade de patologias benignas e malignas podem ser encontradas neste espaço, o que cria desafios complexos de diagnóstico e tratamento. Objetivo: Descrever e analisar uma série de casos de neoplasias primárias do espaço parafaríngeo tratadas no Instituto Português de Oncologia de Lisboa Francisco Gentil (IPOLFG). Material e métodos: Estudo retrospetivo, com recolha e análise dos dados dos processos clínicos de tumores primários do espaço parafaríngeo, que foram diagnosticados ou referenciados ao IPOLFG entre 1 de Janeiro de 2003 e 31 de Dezembro de 2013. Resultados: Foram incluídos 38 doentes. A idade mediana foi de 52 anos (Âmbito Interquartil: 40-63 anos). Dez (26,3%) doentes eram assintomáticos. O sintoma mais comum à apresentação foi a sensação de corpo estranho orofaríngeo (23,7%) e o achado mais frequente foi um abaulamento orofaríngeo (78,4%). Todos os doentes fizeram exames de imagem pré-operatórios: 94,7% tomografia computorizada e 68,4% ressonância magnética. A citologia aspirativa foi realizada em 39,5%. 31 tumores eram benignos (81,6%), sendo os mais frequentes os adenomas pleomórficos (58,1%). 7 eram malignos (18,4%), com os carcinomas exadenomas pleomórficos (28,6%) e os linfomas (28,6%) sendo os mais comuns. 36 doentes (94,7%) foram submetidos a tratamento cirúrgico primário; os outros 2 doentes (5,3%) receberam tratamento não cirúrgico, com quimioterapia e quimioradioterapia, respectivamente. A abordagem cervical foi a mais utilizada (80%). A mandibulotomia foi necessária em apenas 5,7%. A complicação mais frequente foi a neuropatia de pares cranianos de novo, identificada em 22,2%. Destes, 75% foram sequela da resseção de tumores neurogénicos. Todas as neuropatias que resultaram da resseção de tumores não neurogénicos foram transitórias. O follow-up mediano foi de 6,5 anos. A taxa de recorrência foi de 13,5%. Conclusões: Os tumores do espaço parafaríngeo requerem um elevado índice de suspeição para serem diagnosticados num estadio precoce. A resseção cirúrgica completa é o principal tratamento. A abordagem cirúrgica deve ser selecionada caso a caso, mas a cervical fornece um excelente acesso à maioria dos tumores deste espaçoIntroduction: Parapharyngeal space neoplasms are rare, accounting for only 0.5% of head and neck tumors. The majority of PPS tumors are benign, but a wide spectrum of pathologies, both benign and malignant, has been encountered in this region. This range of histopathologies in combination with the complex anatomy of the parapharyngeal space creates complex diagnostic and management challenges. Objective: To describe and analyze a case series of primary parapharyngeal space neoplasms at Instituto Português de Oncologia de Lisboa Francisco Gentil (IPOLFG). Methods: Retrospective review of medical records of patients with parapharyngeal space neoplasms, diagnosed or referred to IPOLFG between 1st of January of 2003 and 31st of December of 2013. Results: 38 patients were included. The median age was 52 years (Interquartile range 40-63). 10 patients (26.3%) were asymptomatic. The most common symptom was an oropharyngeal lump sensation (23.7%). All patients had preoperative imaging: 94.7% computed tomography and 68.4% magnetic resonance image. 39.5% underwent fineneedle aspiration biopsy. 31 tumors were benign (81.6%), with pleomorphic adenomas comprising the majority (58.1%). 7 were malignant (18.4%), with carcinoma ex pleomorphic adenoma (28.6%) and lymphoma (28.6%) being the most common. 36 patients (94.7%) underwent primary surgical management; the other 2 patients (5,3%) were treated with chemotherapy and chemoradiotherapy, respectively. The cervical approach was the most common (80%). A mandibulotomy was required in just 5.7% of primary cases. The most frequent complication was cranial neuropathy, identified in 22,2%. Of these, 75% were sequelae from resection of neurogenic tumors. Median follow-up was 6.5 years. Conclusion: PPS tumors require a high index of suspicion to diagnose them at an early stage. Complete surgical resection is the mainstay of treatment. The optimum surgical approach needs to be selected on an individual basis, but the cervical approach is safe and effective for most PPS neoplasms

    The influence of age diversity practices on workers’ well-being and intention to leave:The role of the relational psychological contract

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    O envelhecimento da população mundial acarreta inúmeros desafios para as organizações, entre os quais a retenção de uma força de trabalho cada vez mais diversa em termos de idade. Com base nas teorias do contrato psicológico e da troca social, este estudo examina o efeito das práticas de diversidade etária no bem-estar subjetivo e na intenção de saída dos trabalhadores via contrato psicológico relacional. Uma amostra de 257 trabalhadores portugueses respondeu a um questionário. A análise de equações estruturais foi aplicada para testar o modelo de mediação. Os resultados mostraram que a existência de práticas de diversidade etária contribui para o desenvolvimento de um contrato psicológico do tipo relacional o que, por sua vez, leva a maiores níveis de bem-estar e a menores intenções de saída da organização. As implicações teóricas e práticas dos resultados são discutidas.info:eu-repo/semantics/publishedVersio

    Co-firing of biomass and other wastes in fluidised bed systems

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    A project on co-firing in large-scale power plants burning coal is currently funded by the European Commission. It is called COPOWER. The project involves 10 organisations from 6 countries. The project involves combustion studies over the full spectrum of equipment size, ranging from small laboratory-scale reactors and pilot plants, to investigate fundamentals and operating parameters, to proving trials on a commercial power plant in Duisburg. The power plant uses a circulating fluidized bed boiler. The results to be obtained are to be compared as function of scale-up. There are two different coals, 3 types of biomass and 2 kinds of waste materials are to be used for blending with coal for co-firing tests. The baseline values are obtained during a campaign of one month at the power station and the results are used for comparison with those to be obtained in other units of various sizes. Future tests will be implemented with the objective to achieve improvement on baseline values. The fuels to be used are already characterized. There are ongoing studies to determine reactivities of fuels and chars produced from the fuels. Reactivities are determined not only for individual fuels but also for blends to be used. Presently pilot-scale combustion tests are also undertaken to study the effect of blending coal with different types of biomass and waste materials. The potential for synergy to improve combustion is investigated. Early results will be reported in the Conference. Simultaneously, studies to verify the availability of biomass and waste materials in Portugal, Turkey and Italy have been undertaken. Techno-economic barriers for the future use of biomass and other waste materials are identified. The potential of using these materials in coal fired power stations has been assessed. The conclusions will also be reported

    Gaseous emissions during concurrent combustion of biomass and non-recyclable municipal solid waste

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    Background: Biomass and municipal solid waste offer sustainable sources of energy; for example to meet heat and electricity demand in the form of combined cooling, heat and power. Combustion of biomass has a lesser impact than solid fossil fuels (e. g. coal) upon gas pollutant emissions, whilst energy recovery from municipal solid waste is a beneficial component of an integrated, sustainable waste management programme. Concurrent combustion of these fuels using a fluidised bed combustor may be a successful method of overcoming some of the disadvantages of biomass (high fuel supply and distribution costs, combustion characteristics) and characteristics of municipal solid waste (heterogeneous content, conflict with materials recycling). It should be considered that combustion of municipal solid waste may be a financially attractive disposal route if a 'gate fee' value exists for accepting waste for combustion, which will reduce the net cost of utilising relatively more expensive biomass fuels. Results: Emissions of nitrogen monoxide and sulphur dioxide for combustion of biomass are suppressed after substitution of biomass for municipal solid waste materials as the input fuel mixture. Interactions between these and other pollutants such as hydrogen chloride, nitrous oxide and carbon monoxide indicate complex, competing reactions occur between intermediates of these compounds to determine final resultant emissions. Conclusions: Fluidised bed concurrent combustion is an appropriate technique to exploit biomass and municipal solid waste resources, without the use of fossil fuels. The addition of municipal solid waste to biomass combustion has the effect of reducing emissions of some gaseous pollutants

    Seasonal water level fluctuations: Implications for reservoir limnology and management

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    With the purpose of finding out whether seasonal water level fluctuations could affect water quality in a reservoir subjected to those changes, trends in environmental variables and in phytoplankton and zooplankton assemblages were analysed. The reservoir’s hydrological cycle was characterized by three regimes. The maximum level phase lasted from January to the beginning of June, the emptying phase existed between mid-June to the beginning of September and the minimum level phase lasted from mid-September to the beginning of the first autumn/winter rain events. The highest values of total phosphorus, soluble reactive phosphorus, nitrate, water colour and chlorophyll a were found during the minimum level phase. The phytoplankton assemblage was dominated by taxa typical of meso-eutrophic environments during the emptying and minimum level phases. However, during the maximum level phase, taxa generally found in more oligotrophic systems were observed here also. Similar to other disturbed systems, the zooplankton assemblage was dominated by Rotifera, except in summer and autumn when the cladoceran Ceriodaphnia quadrangula and/or the copepod Tropocyclops prasinus became dominant. Although those shifts seem to be related to water level variations, further research is needed to evaluate to what extent they might also be induced by other seasonal factors acting independently of water fluctuations. Based upon the obtained data, suggestions for reservoir management are proposed

    Germline MUTYH (MYH) mutations in Portuguese individuals with multiple colorectal adenomas

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    Germinal mutations in the base excision repair (BER) gene MUTYH (MYH) have recently been described in association with predisposition to multiple colorectal adenomas and cancer. In contrast to the classic dominant condition of familial adenomatous polyposis (FAP) due to germinal mutations in the APC gene, the MYH polyposis is an autosomal recessive disease. The identification of individuals affected by MYH polyposis brings new and important implications for the diagnostic, screening, genetic counseling, follow up and therapeutic options in these patients. In this study, screening for germinal mutations in the MYH gene was performed in 53 Portuguese individuals with multiple colorectal adenomas or classic adenomatous polyposis, in whom no mutation had been identified in the APC gene. The results revealed the presence of biallelic germline MYH mutations in 21 patients. In addition, we here report 3 mutations (c.340T>C [p.Y114H]; c.503G>A [p.R168H]; and c.1186_1187insGG [p.E396fsX437]) which, to our knowledge, have not been previously describe

    Presence of the Eucalyptus gall wasp Ophelimus maskelli and its parasitoid Closterocerus chamaeleon in Portugal: first record, geographic distribution and host preference

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    The Eucalyptus gall wasp Ophelimus maskelli (Hymenoptera: Eulophidae) and its parasitoid Closterocerus chamaeleon (Hymenoptera: Eulophidae) were observed for the first time in Portugal, in 2006 and 2007, respectively. Data on the distribution of O. maskelli in Portugal, differences in the susceptibility of two host species, Eucalyptus globulus and Eucalyptus camaldulensis, and parasitism by C. chamaeleon are given
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