246 research outputs found

    Do Littoral Macrophytes Influence Crustacean Zooplankton Distribution?

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    In a meso-eutrophic reservoir, cladoceran and copepod assemblages were characterised in two sampling sites: One located in the pelagic zone (site 1) and the other in the shallow littoral zone (site 2), the latter colonised by emergent macrophytes. Samples were collected biweekly from June to July 2001 and from May to July 2002 at the two sites. At site 1, crustacean zooplankton samples were obtained by vertical hauls using a Wisconsin type net of 64 mm mesh size. At site 2 several random samples were obtained using a van Dorn bottle. Those samples were pooled together and the total sample was sieved through a 64 mm mesh size. Macrophyte relative abundance for each species was visually estimated. Macrophyte community was composed of Glyceria declinata, Eleocharis palustris and Carex sp. A Mann-Whitney U-test was carried out to test for statistically significant differences between sites, for environmental parameters and crustacean zooplankton species densities. Alona rectangula, Alona costata, Alona quadrangularis and Chydorus sphaericus were only found in littoral samples. Daphnia longispina, Daphnia pulex, Ceriodaphnia pulchella, Bosmina longirostris, Diaphanosoma brachyurum, Copidodiaptomus numidicus, and Acanthocyclops robustus were found at both sites. However, Daphnia and Bosmina densities did not differ significantly between the pelagic and littoral sites. Ceriodaphnia, Diaphanosoma, and C. numidicus densities were significantly higher in the pelagic site, whereas A. robustus densities showed the opposite pattern.En un embalse meso-eutrofico las comunidades de cladóceros y copépodos fueron caracterizadas en dos estaciones de muestreo. Una localizada en la zona pelágica (estación 1) y la otra en la zona litoral (estación 2). Esta última está colonizada por macrofitos emergidos. Los muestreos fueron efectuados quincenalmente de Junio a Julio de 2001 y de Mayo a Julio de 2002 en las dos estaciones. En la estación 1 los muestreos de crustáceos del zooplancton se obtuvieron mediante arrastre vertical utilizando una red tipo Wisconsin de 64 mm de poro. En la estación 2 se realizaron varias muestras aleatorias con una botella tipo van Dorn. Las muestras obtenidas en la estación 2 se juntaron y la muestra total resultante fue filtrada por una red de 64 mm de poro. La abundancia relativa de cada una de las especies de macrófitos fue estimada visualmente. La comunidad de macrófitos está constituida por Glyceria declinata, Eleocharis palustris y Carex sp. Fue realizado el test de U de Mann-Whitney para detectar las diferencias estadísticamente significativas entre las dos estaciones, para los parámetros ambientales y para las densidades de los crustáceos del zooplancton. Alona rectangula, Alona costata, Alona quadrangularis y Chydorus sphaericus se han observado únicamente en los muestreos obtenidos en el litoral. Daphnia longispina, Daphnia pulex, Ceriodaphnia pulchella, Bosmina longirostris, Diaphanosoma brachyurum, Copidodiaptomus numidicus y Acanthocyclops robustus se han encontrado en ambas estaciones, no obstante las densidades de Daphnia y Bosmina no presentan diferencias estadísticamente significativas entre la zona pelágica y la litoral. Las densidades de Ceriodaphnia, Diaphanosoma y C. numidicus fueran significativamente más elevadas en la zona pelágica, mientras que la densidad de A. robustus presentó un patrón opuesto

    High risk of cardiovascular episodes and low adherence to risk factors guidelines in a population with diabetes

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    Although recent guidelines cover therapeutic goals, effective lipid management of patients with type 1 and type 2 diabetes to reduce cardiovascular disease (CVD) risk is still largely unattained. In the present study, we explored the electronic health records (EHR) at a specialized diabetes outpatient clinic to assess, in a real world database, the prevalence of poor lipid management in people with diabetes, the associated characteristics of this population, and the patterns of medication.Amge

    Conceptions of basic education teachers about math proof: influence of professional experience

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    A prova é uma atividade que desempenha um papel fundamental na construção do conhecimento matemático, razão pela qual adquire relevância nos programas escolares de Matemática. Admitindo que as conceções dos professores sobre a prova afetam a forma como ela é tratada em sala de aula, procuramos averiguar as conceções de professores portugueses de Matemática do 3.º ciclo do Ensino Básico (do 7.º ao 9.º ano) sobre diferentes aspetos da prova matemática e a influência que a experiência profissional tem nessas conceções. Adotando uma abordagem metodológica mista, recolhemos os dados através de um questionário, respondido por 72 professores, e de uma entrevista a duas professoras com experiências profissionais diferentes. Os resultados revelam que os professores, sobretudo os que têm menos tempo de docência, consideram que a prova matemática tem uma natureza distinta da de outras disciplinas, é uma atividade essencial para a construção do conhecimento matemático, tem como função verificar e explicar a veracidade de uma afirmação e permite desenvolver o raciocínio e a comunicação matemática. No que respeita à participação dos alunos na atividade de provar, são os professores com mais tempo de docência que mais o destacam, o que permite aos alunos perceberem a natureza desta atividade. Em termos curriculares, são os professores com menos experiência docente que mais concordam com a presença da prova logo nos primeiros anos, embora salientem que esta atividade só faz sentido em alguns tópicos programáticos.Proof is an activity that plays a key role in the construction of mathematical knowledge, which is why it acquires relevance in mathematics programs. Admitting that teachers' conceptions about proof influence how it is handled in the classroom, we tried to investigate the conceptions of Portuguese mathematics teachers from the 3rd cycle of basic education (grade 7 to 9) on different aspects of mathematical proof and the relationship that the teachers’ experience has in these conceptions. Adopting a mixed methodological approach, we collected data through a questionnaire answered by 72 teachers, and an interview with two teachers with different professional experience. The results show that teachers, especially those with less experience, consider that mathematical proof has a distinct nature from other disciplines, it is an essential activity for the construction of mathematical knowledge and its function is to verify and explain the truth of a statement by developing reasoning and mathematical communication. With respect to student participation in the activity of proving, teachers with more teaching experience are the ones that most highlight it, which allows students to realize the nature of this activity. In curriculum terms, teachers with less experience are the ones that most agree with the presence of proof in early grades, while emphasizing that this activity only makes sense in some program topics.Este trabalho contou com o apoio de Fundos Nacionais através da FCT – Fundação para a Ciência e a Tecnologia no âmbito do projeto PEst-OE/CED/UI1661/2014, do CIEdUM e do projeto UID/Multi/04016/2016info:eu-repo/semantics/publishedVersio

    Flavoured searches for type-III seesaw at the LHC

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    We present a reinterpretation of CMS searches for type-III seesaw lepton triplets at the LHC, both for the normal and the inverse seesaw. We find that, in contrast with previous expectations, these searches in the trilepton final state have a good sensitivity to triplets with predominant coupling to the tau lepton. We also show that the limits resulting from direct searches can be neatly presented for arbitrary masses and general flavour mixings. Thus, it turns out that the common (and often unrealistic) simplifying assumptions about the flavour couplings of the triplets used by experimental collaborations to present their results are unnecessary and should be dropped.This work has been supported by Fundação para a Ciência e a Tecnologia (FCT, Portugal) and Ministerio de Ciencia e Innovación (MICINN, Spain) under the bilateral project “Signals of new fermions at colliders” (FCT/1683/27/1/2012/S, AIC-D-2011-0811). F.R.J. and P.M.B. acknowledge support from FCT through the projects CERN/FP/123580/2011, PTDC/FIS/102120/2008 and PEst-OE-FIS-UI0777-2013. J.A.A.S. acknowledges support from MICINN through the projects FPA2006-05294 and FPA2010-17915; from Junta de Andalucía (FQM 101 and FQM 6552) and from FCT (project CERN/ FP/123619/2011)

    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

    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

    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

    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

    Exploring the response of a key Mediterranean gorgonian to heat stress across biological and spatial scales

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    Understanding the factors and processes that shape intra-specific sensitivity to heat stress is fundamental to better predicting the vulnerability of benthic species to climate change. Here, we investigate the response of a habitat-forming Mediterranean octocoral, the red gorgonian Paramuricea clavata (Risso, 1826) to thermal stress at multiple biological and geographical scales. Samples from eleven P. clavata populations inhabiting four localities separated by hundreds to more than 1500 km of coast and with contrasting thermal histories were exposed to a critical temperature threshold (25 degrees C) in a common garden experiment in aquaria. Ten of the 11 populations lacked thermotolerance to the experimental conditions provided (25 days at 25 degrees C), with 100% or almost 100% colony mortality by the end of the experiment. Furthermore, we found no significant association between local average thermal regimes nor recent thermal history (i.e., local water temperatures in the 3 months prior to the experiment) and population thermotolerance. Overall, our results suggest that local adaptation and/or acclimation to warmer conditions have a limited role in the response of P. clavata to thermal stress. The study also confirms the sensitivity of this species to warm temperatures across its distributional range and questions its adaptive capacity under ocean warming conditions. However, important inter-individual variation in thermotolerance was found within populations, particularly those exposed to the most severe prior marine heatwaves. These observations suggest that P. clavata could harbor adaptive potential to future warming acting on standing genetic variation (i.e., divergent selection) and/or environmentally-induced phenotypic variation (i.e., intra- and/or intergenerational plasticity).European Commission SEP-210597628- FutureMARES, MCIU/AEI/FEDER RTI2018-095346-BI00, Spanish government through the `Severo Ochoa Centre of Excellence' accreditation CEX2019-000928-S , Interreg Med Programme 5216|5MED18_3.2_M23_007, 1MED15_3.2_M2_ 337, Spanish Government FPU15/05457, Fundacao para a Ciencia e a Tecnologia (FCT) LA/P/0101/2020 , DivRestore/0013/2020, Marine Conservation research group 2017 SGR 1521, postdoctoral fellowship of project HABMAR - European Maritime and Fisheries Fund of the Operational Program MAR 2020 for Portugal MAR-01.04.02-FEAMP-0018info:eu-repo/semantics/publishedVersio

    Loss of heterozygosity at 7p in Wilms' tumour development

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    Chromosome 7p alterations have been implicated in the development of Wilms' tumour (WT) by previous studies of tumour cytogenetics, and by our analysis of a constitutional translocation (t(1;7)(q42;p15)) in a child with WT and radial aplasia. We therefore used polymorphic microsatellite markers on 7p for a loss of heterozygosity (LOH) study, and found LOH in seven out of 77 informative WTs (9%). The common region of LOH was 7p15–7p22, which contains the region disrupted by the t(1;7) breakpoint. Four WTs with 7p LOH had other genetic changes; a germline WT1 mutation with 11p LOH, LOH at 11p, LOH at 16q, and loss of imprinting of IGF2. Analysis of three tumour-associated lesions from 7p LOH cases revealed a cystic nephroma-like area also having 7p LOH. However, a nephrogenic rest and a contralateral WT from the two other cases showed no 7p LOH. No particular clinical phenotype was associated with the WTs which showed 7p LOH. The frequency and pattern of 7p LOH demonstrated in our studies indicate the presence of a tumour suppressor gene at 7p involved in the development of Wilms' tumour. © 2000 Cancer Research Campaig
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