Evaluation of noise environments during daily activities of university students

Noise conditions specifically in areas inside university facilities and its impact on the quality of life of university students aretopics that have received little attention. In this paper, a study of the noise conditions in which university students of various institutions in Madrid carry out their daily studies. A representative number of measurements were carried out using noise dosemeters and dataloggers in order to evaluate the levels of noise, noise dose and exposure to noise during study period and extracurricular activities. The results obtained in these measurements were compared with the recommendations given by current environmental noise regulations.This paper was complemented with a survey to get to know how students perceive the exposure to noise inuniversity environments.

Mutation of Residue Threonine-2 of the D2 Polypeptide and Its Effect on Photosystem II Function in Chlamydomonas reinhardtii1

The D2 polypeptide of the photosystem II (PSII) complex in the green alga Chlamydomonas reinhardtii is thought to be reversibly phosphorylated. By analogy to higher plants, the phosphorylation site is likely to be at residue threonine-2 (Thr-2). We have investigated the role of D2 phosphorylation by constructing two mutants in which residue Thr-2 has been replaced by either alanine or serine. Both mutants grew photoautotrophically at wild-type rates, and noninvasive biophysical measurements, including the decay of chlorophyll fluorescence, the peak temperature of thermoluminescence bands, and rates of oxygen evolution, indicate little perturbation to electron transfer through the PSII complex. The susceptibility of mutant PSII to photoinactivation as measured by the light-induced loss of PSII activity in whole cells in the presence of the protein-synthesis inhibitors chloramphenicol or lincomycin was similar to that of wild type. These results indicate that phosphorylation at Thr-2 is not required for PSII function or for protection from photoinactivation. In control experiments the phosphorylation of D2 in wild-type C. reinhardtii was examined by 32P labeling in vivo and in vitro. No evidence for the phosphorylation of D2 in the wild type could be obtained. [14C]Acetate-labeling experiments in the presence of an inhibitor of cytoplasmic protein synthesis also failed to identify phosphorylated (D2.1) and nonphosphorylated (D2.2) forms of D2 upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Our results suggest that the existence of D2 phosphorylation in C. reinhardtii is still in question.

Heterogeneity and Photoinhibition of Photosystem II Studied with Thermoluminescence1

Thermoluminescence (TL) signals were recorded from grana stacks, margins, and stroma lamellae from fractionated, dark-adapted thylakoid membranes of spinach (Spinacia oleracea L.) in the absence and in the presence of 2,6-dichlorphenylindophenol (DCMU). In the absence of DCMU, the TL signal from grana fractions consisted of a homogenous B-band, which originates from recombination of the semi-quinone QB− with the S2 state of the water-splitting complex and reflects active photosystem II (PSII). In the presence of DCMU, the B-band was replaced by the Q-band, which originates from an S2QA− recombination. Margin fractions mainly showed two TL-bands, the B- and C-bands, at approximately 50°C in the absence of DCMU, and Q- and C-bands in the presence of DCMU. The C-band is ascribed to a TyrD+-QA− recombination. In the absence of DCMU, the fractions of stromal lamellae mainly gave rise to a TL emission at 42°C. The intensity of this band was independent of the number of excitation flashes and was shifted to higher temperatures (52°C) after the addition of DCMU. Based on these observations, this band was considered to be a C-band. After photoinhibitory light treatment of uncoupled thylakoid membranes, the TL intensities of the B- and Q-bands decreased, whereas the intensity at 45°C (C-band) slightly increased. It is proposed that the 42 to 52°C band that was observed in marginal and stromal lamellae and in photoinhibited thylakoid membranes reflects inactive PSII centers that are assumed to be equivalent to inactive PSII QB-nonreducing centers.

Acridones: a chemically new group of protonophores.

Although the interaction of proton-conducting ionophores (protonophores) with photosynthetic electron transport has been extensively studied during the past decade, the mode of action of protonophores remained uncertain. For a better understanding of the molecular mechanism of the action of protonophores, the introduction of chemically new types of molecules will be required. In this work, we demonstrate that acridones (9-azaanthracene-10-ones) completely fulfill this requirement. At low concentrations of acridones, the thermoluminescence bands at +20 degrees C and +10 degrees C were strongly inhibited, while normal electron transport activity was retained. This indicates that the concentrations of S2 and S3 states involved in the generation of these bands are reduced. At higher concentrations, an increased activity of electron transport was observed, which is attributed to the typical uncoupler effect of protonophores. Indeed, acridones accelerate the decay of the electrochromic absorbance change at 515 nm and also inhibit the generation of the transmembrane proton gradient, measured as an absorbance transient of neutral red. Variable fluorescence induction was quenched even at low concentrations of acridones but was restored by either a long-term illumination or high light intensity. Acridones, similarly to other protonophores, promoted the autooxidation of the high-potential form of cytochrome b559 and partially converted it to lower potential forms. These results suggest that acridones, acting as typical protonophores, uncouple electron transport, accelerate the deactivation of the S2 and S3 states on the donor side, and facilitate the oxidation of cytochrome b559 on the acceptor side of photosystem II.

Avaliação dos níveis de radiação ambiental no laboratório de tomografia por emissão de pósitrons acoplada a tomografia computadorizada, microPET/CT

O sistema microPET/CT é um importante equipamento utilizado nas pesquisas de imagem diagnóstica em pequenos animais. O radiofármaco mais usado nesta tecnologia é o fluordeoxiglicose marcado com flúor-18. Este estudo tem como objetivo efetuar o controle radiológico no laboratório de pesquisa microPET/CT do Centro de Radiofarmácia do IPEN-CNEN/SP, de forma a satisfazer tanto as normas nacionais como as recomendações internacionais. O laboratório está classificado pela equipe de radioproteção da instalação como área supervisionada, nas quais embora não seja obrigatória a adoção de medidas específicas de proteção e segurança, devem ser submetidas reavaliações regulares das condições do ambiente de trabalho. Visando assegurar a proteção radiológica dos trabalhadores diretamente envolvidos no manuseio do equipamento, realizou-se o monitoramento do local de trabalho e a avaliação do controle de dose individual. Inicialmente foi feito o monitoramento pré-operacional, isto é, o levantamento radiométrico no laboratório. Além disso, mediu-se nível de radiação externa nas instalações do laboratório e suas adjacências, por meio da colocação de nove dosímetros termoluminescentes (TL) de CaSO4:Dy, em locais previamente selecionados. Os indivíduos ocupacionalmente expostos foram avaliados mensalmente por meio do uso de dosímetros TL posicionados no tórax e por medidas de corpo inteiro, tomadas a cada seis meses. O período do estudo foi de dois anos, com início em abril de 2014. Para o controle do microPET/CT realizou-se testes de desempenho de acordo com o protocolo padrão do equipamento e em conformidade com a norma desenvolvida pela força tarefa para estudos com PET em animais Animal PET Standard Task Force. O presente estudo permitiu demonstrar que os níveis de radiação das áreas (estimativas de dose ambiente e dose efetiva), assim como a blindagem do equipamento estão adequados de acordo com os limites da exposição ocupacional. Ressalta-se a importância de se seguir rigorosamente os princípios de radioproteção, já que se trata de pesquisas com fontes radioativas não seladas.

Factors affecting the use of CaF2 : Mn thermoluminescent dosimeters for low-level environmental radiation monitoring /

Mode of access: Internet.

Palaeoenvironment records of six sediment cores collected in the Gulf of Carpentaria

The Gulf of Carpentaria is an epicontinental sea (maximum depth 70 m) between Australia and New Guinea, bordered to the east by Torres Strait (currently 12 m deep) and to the west by the Arafura Sill (53 m below present sea level). Throughout the Quaternary, during times of low sea-level, the Gulf was separated from the open waters of the Indian and Pacific Oceans, forming Lake Carpentaria, an isolation basin, perched above contemporaneous sea-level with outlet channels to the Arafura Sea. A preliminary interpretation is presented of the palaeoenvironments recorded in six sediment cores collected by the IMAGES program in the Gulf of Carpentaria. The longest core (approx. 15 m) spans the past 130 ka and includes a record of sea-level/lake-level changes, with particular complexity between 80 and 40 ka when sea-level repeatedly breached and withdrew from Gulf/Lake Carpentaria. Evidence from biotic remains (foraminifers, ostracods, pollen), sedimentology and geochemistry clearly identifies a final marine transgression at about 9.7 ka (radiocarbon years). Before this transgression, Lake Carpentaria was surrounded by grassland, was near full, and may have had a surface area approaching 600 km-300 km and a depth of about 15 m. The earlier rise in sea-level which accompanied the Marine Isotopic Stage 6/5 transgression at about 130 ka is constrained by sedimentological and biotic evidence and dated by optical- and thermoluminescence and amino acid racemisation methods.

Pesquisa, desenvolvimento e caracterizacao de materiais dosimetricos para monitoramento em processos de irradiacao com doses altas

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)