Browsing by Issue Date, starting with "2010-03"
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- Fishing simulation experiments for predicting the effects of purse-seine capture on sardine (Sardina pilchardus)Publication . Marçalo, Ana; Araújo, João; Pousão-Ferreira, P.; Erzini, Karim; Stratoudakis, YorgosTo study the impact of purse-seine fishing on deliberately released sardine, two laboratory experiments were performed to explore the effect of net confinement for 10, 20, 40, and 60 min at 18 and 238 degrees C. A third experiment considered two levels of fish density while confined for 20 and 40 min at 16 degrees C. Analysis of cortisol and haematocrit demonstrated that stress immediately after simulated fishing was milder than in commercial fishing and did not correlate with observed delayed mortality. Scale loss was related to the probability of dying (mean values of 16.3 and 2% for dead fish and survivors, respectively), and fin erosion was a long-term stress response observed in both dead and surviving fish. Time of confinement was an important stressor, with survival rates decreasing significantly with increasing periods in the net, and temperature having an additional negative effect. Density effects were less conclusive, but there was some indication that survival correlated with biological condition (heavier fish were more likely to survive). It seems that delayed mortality after release can be substantial, although death is not certain and appropriately modified fishing operations and favourable environmental conditions may enhance the probability of sardine survival.
- First isotopic records from stalagmites in Algarve (South Portugal)Publication . Veiga-Pires, C.; Moura, Delminda; Luis, Joaquim; Varela, J.; Ghaleb, Bassam; Hélie, Jean-François; Hillaire-Marcel, C.Os espeleotemas representam registos paleoclimáticos continentais de alta resolução e estão a ser cada vez mais estudos para fins de reconstrução climática de períodos não afectados por acções antropogénicas. Na região do Algarve (Sul de Portugal), a existência de formações carbonatadas do Jurássico e Cretácico permitiu um desenvolvimento de sistemas cársicos onde se encontram actualmente estruturas estalagmíticas. Neste estudo preliminar realizado sobre estas estalagmites da região do Algarve, foram realizadas datações U/Th e análises de isótopos estáveis que demonstram pela primeira vez a possibilidade de obter registos isotópicos continentais representativos do paleoclima do extremo Sudoeste da Península Ibérica.
- Characterization of the variable exponent Bessel potential spaces via the Poisson semigroupPublication . Rafeiro, Humberto; Samko, StefanUnder the standard assumptions on the variable exponent p(x) (log- and decay conditions), we give a characterization of the variable exponent Bessel potential space B(alpha)[L(p(-))(R(n))] in terms of the rate of convergence of the Poisson semigroup P(t). We show that the existence of the Riesz fractional derivative D(alpha) f in the space L(p(-))(R(n)) is equivalent to the existence of the limit 1/epsilon(alpha)(I - P(epsilon))(alpha) f. In the pre-limiting case sup(x) p(x) < n/alpha we show that the Bessel potential space is characterized by the condition parallel to(I - P(epsilon))(alpha) f parallel to p((.)) <= C epsilon(alpha). (C) 2009 Elsevier Inc. All rights reserved.
- New insights into the regulation of CYP2C9 gene expression: The role of the transcription factor GATA-4Publication . Mwinyi, Jessica; Nekvindova, Jana; Cavaco, Isa; Hofmann, Yvonne; Pedersen, Rasmus Steen; Landman, Ellie; Mkrtchian, Souren; Ingelman-Sundberg, MagnusCYP2C9 is an important drug-metabolizing enzyme that metabolizes, e. g., warfarin, antidiabetics, and antiphlogistics. However, the endogenous regulation of this enzyme is largely unknown. In this study, we examined the role of GATA transcription factors in the gene expression of CYP2C9. We investigated four putative GATA binding sites within the first 200 base pairs of CYP2C9 promoter at the positions I: -173/-170, II: -167/-164, III: -118/ -115, and IV: -106/-103. Luciferase activity driven by a wildtype CYP2C9 promoter construct was strongly up-regulated in Huh-7 cells upon cotransfection with expression plasmids for GATA-2 and GATA-4, whereas mutations introduced into GATA binding site III or I and II reduced this induction to a significant extent. Electrophoretic mobility shift assays revealed specific binding of GATA-4 and GATA-6 to the oligonucleotides containing GATA binding sites I and II. Furthermore, the association of GATA-4 with CYP2C9 promoter was confirmed by chromatin immunoprecipitation assays in HepG2 cells. Taken together, these data strongly suggest an involvement of liver-specific transcription factor GATA-4 in the transcriptional regulation of CYP2C9.
- Delimitação de áreas inundáveis por acção fluvial: aplicação ao Rio Séqua/Gilão na área urbana de TaviraPublication . MGP Isidoro, Jorge; Rocheta, Vera Lúcia da Silva; Lança, RuiA Universidade do Algarve realizou em 2008 um estudo para o Município de Tavira relativo à delimitação das áreas inundáveis causadas por extravasamento do rio que atravessa a cidade, Rio Séqua/Gilão, devido a precipitações intensas associadas a períodos de retorno de 10 e de 100 anos. O estudo em causa dividiu-se basicamente em três etapas: a realização de um estudo hidrológico da bacia hidrográfica do Rio Séqua/Gilão (221km2) com vista a determinação de caudais máximos de cheia, a realização de um estudo hidrodinâmico, no qual se efectuou a modelação numérica do troço de rio com aproximadamente 9.50km, considerando o efeito das diversas estruturas hidráulicas existentes no troço e do efeito de maré, e finalmente a identificação dos níveis atingidos pelo Rio para os caudais associados a períodos de retorno de 10 e 100 anos. Foram também analisados os resultados obtidos e identificadas soluções para minimizar o efeito das cheias na cidade de Tavira. Particular atenção foi dada à aferição do modelo utilizado, através da comparação entre os níveis de cheia atingidos na cheia de 3 de Dezembro de 1989 (através de marcas de cheia, fotografias e vídeos) e os níveis de cheia modelados. Este exercício permitiu verificar que o modelo numérico apresenta resultados muito satisfatórios nas simulações efectuadas. Foi também realizada uma simulação tendo em conta potenciais efeitos das alterações climáticas no que concerne à subida do nível médio do mar. Pretende-se apresentar uma síntese das etapas que constituíram o estudo, dando particular incidência ao trabalho de aferição existente, bem como à elaboração dos mapas de delimitação de áreas inundáveis.
- Determination of cyclophosphamide in human urine by HPLC coupled to tandem mass spectrometryPublication . Marahatta, Anu; Wasik, Agata Kot; Wasik, AndrzejBiological samples urine are much more complex due to presence of proteins, salts, acids, bases and various organic compounds with similar chemistry to analytes of interest. As a result, the extraction methods for biological samples have been difficult. The main task was to remove maximum interfering substance from urine matrix and conversion of analytes into a more suitable form for injection. Therefore, optimization of SPE method was done by changing different parameter such as different type and amount of sorbent, composition and volume of elution, washing solvent. The use of 24 well SPE plate for matrix purification significantly allows the use of small urine and solvent volumes, reduces the sample preparation time and ensures a high throughput, thus allowing the routine biological monitoring of CP as indices of human exposures. In order to investigate the effectiveness of the SPE method tests were repeated on Strata-X cartridge and method showed good recovery (above 75 %) of CP. After optimizing SPE method, CP separation conditions of the HPLC-MS/MS analysis was achieve by changing different parameter such as suitable mobile phase and its composition, flow rate, scan type, polarity. The LC separation was performed on Lichrocart® 100 RP-18 column (125 4 mm, particle size of 5 μm) with 1 mM formic acid with ammonia buffer pH 3 and methanol using gradient program at a flow rate 1 mL/min with total run time 15 min. A reversed phase HPLC system was interfaced with an ESI source coupled to tandem mass spectrometry. The triple quadrupole mass spectrometer was operated in positive ion mode and MRM was used for analysis of CP. LOD and LOQ were 0.27 ng/mL and 0.54 ng/mL. A sensitive, specific and accurate HPLC/MS/MS has been developed for monitoring CP in urine samples. The use of reversed phase HPLC coupled to tandem mass spectrometry has facilitated the analysis of CP in short retention time. Fifteen urine samples were collected from medical personnel of Medical University of Gdansk, who were exposed with CP during their work in pharmacy. SPE-HPLC-MS/MS method was applied for the analysis of health workers and all urine samples from university workers has CP below analytical limit of detection.
- Applicability of head space solid phase microextraction (HS-SPME) with polyethylene glycol (PEG) fibre for GC-MS determination of volatile fatty acids in aqueous samplesPublication . Faniband, Moosa Hassan; Zygmunt, Bogdan; Banel, AnnaA method consisting of head-space solid phase micro extraction (HS-SPME) followed by gas chromatography coupled with mass spectrometry (GC-MS) was developed for determination of volatile fatty acids in wastewater. A new fibre polyethylene glycol (PEG) was evaluated for the sample preparation. This fibre is designed to show high sample capacity, faster mass transfer during extraction, shorter equilibrium times and faster desorption process. The developed method showed good sensitivity with comparable limit of detection (LOD) and limit of quantitation (LOQ) values. The selection of various parameters included extraction time, extraction temperature, sample volume and desorption conditions. The experimental results showed low detection limits ranging between 0.01 mg/L to 0.06 mg/L for different acids. The new fibre was found to be efficient towards acetic and propionic acid.
- Determination of volatile fatty acids in municipal wastewater by gas chromatography-mass spectrometry preceded by headspace- solid phase microextraction with PDMS-CAR fibrePublication . Pokhrel, Teeka Ram; Zygmunt, Bogdan; Banel, AnnaAn analytical procedure based on headspace – solid phase microextraction (HS-SPME) followed by gas chromatography-mass spectrometry (GC-MS) has been developed for the determination of free volatile fatty acids in municipal wastewater samples. Polydimethylsiloxane-Carboxen (PDMS-CAR) fibre was found to have greater affinity to extract lower chain fatty acids. Extraction and gas chromatographic parameters of importance such as desorption time, sample volume, amount of salt to be added and extraction time have been optimized. Detection limits were in the low to medium mg/L levels. To evaluate the applicability of the developed HS-SPME procedure on real samples, municipal wastewater treatment plant samples were analysed.
- Ability of salt marsh plants for TBT remediation in sedimentsPublication . Carvalho, P. N.; Basto, M. C.; F. G. M. Silva, Manuela; Machado, A.; Bordalo, A.; Vasconcelos, M. T.The capability of Halimione portulacoides, Spartina maritima, and Sarcocornia fruticosa (halophytes very commonly found in salt marshes from Mediterranean areas) for enhancing remediation of tributyltin (TBT) from estuarine sediments was investigated, using different experimental conditions.
- O papel das representações dos professores na inserção das tecnologias de informação e comunicação no ensino especialPublication . Santos, Antónia Cristiane dos; Sousa,Carolina Moreira da Silva de FernandesThe theme of this work, «The Role of Representatives of Teachers in the integration of Communication and Information Technologies in Special Education: An exploratory study in the district of Faro», relates, essentially, to the fact of Information and Communication Technologies are at present, increasingly considered and imposed as instruments to support essential and indispensable to the teaching practice and, in particular, teachers of Special Education. This study aims to characterize the representations that teachers of special education are information and communication technologies (ICT) in the context of their teaching practice also identify how these technologies have advantages and influence the tasks of teaching teachers inside and outside the school environment, in a positive way, consider also the influence of the use of ICT on physical, cognitive and social development of pupils with Special Educational Needs (SEN) in various levels of complexity, and promoting to autonomy and social inclusion; assess whether teachers have adequate training to the educational use of ICT and, in accordance with its opinion, the state, schools and teachers have incorporated the concept of inclusive education, and finally identify the difficulties and obstacles hindering the use of ICT in the educational context of non-higher education.