12 research outputs found

    Analysis of PMD induced crosstalk in 2x40 Gbit/s Polarization Multiplexed signals

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    We theoretically and experimentally investigate the PMD tolerance of Intensity-Modulated Polarization Multiplexed signals, both NRZ and RZ. Clock alignment and pulsewidth can be optimised to reduce the impairments

    Remodulation of a subcarrier modulated signal by feed-forward current injection in a reflective SOA

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    We experimentally demonstrated bidirectional transmission of 155 MS/s radio-over-fibre signals at 2.5 GHz. By using feed-forward correction in Reflective R-SOA. Uplink and Downlink share asynchronously the same subcarrier

    Cell-cycle protein modifications in the kidney of Mus spretus from Donana National Park

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    Abstract On April 1998 a tailing dam of the Aznalcollar pyrite mine partially collapsed and released to the Guadiamar river acidic water and mud containing toxic metals threatening the Doñana National Park, a Spanish wildlife reserve located near the estuary of Guadalquivir river. To assess the possible biological effects on terrestrial ecosystems, biochemical markers were assayed in the kidneys of Algerian mice (Mus spretus) collected in several areas of Doñana and Guadiamar river. Biomarkers assayed are proteins involved in cell cycle regulation, in particular cyclins and their associated kinases, and some cell cycle inhibitors. Moreover Mitogen Activated Protein Kinases (MAPK), a signal transduction system involved in cell division, p53, a protein involved in growth arrest after DNA damage, and HSP70, an early stress-induced protein, were assayed. The kidneys of animals collected one year after the ecological disaster had increased levels of PCNA (proliferating cell nuclear antigen), indicating an increased number of cells in the S phase of cell cycle. This shift of cells from G0 to S phase is due to increased levels of cyclins D1, E, and A, to decreased levels of p21 and p27 cdk inhibitors, and to activation of MAPK cascade. On the other hand, p53 and HSP70 levels are not changed. These data demonstrate that the presence of toxic metals after ecological disaster provoked the induction of kidney cell proliferation interpretable as a compensatory cell growth after tissue damage and apoptosis, and that could lead to the genomic instability characteristic of cancer cell

    Genotoxic damage in free-living Algerian mouse (Mus spretus) after the Coto Doñana ecological disaster.

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    The Doñana National Park (Spain), one of the most important wildlife sites in the West of Europe, was affected (25 April 1998) by the spill of acidic waste rich in toxic metals (mainly zinc, lead, copper, etc.), arsenic and aromatic amines from the Aznalcollar mine accident. Micronuclei test with May Grunwald-Giemsa and with CREST-antikinetocore staining using DAPI as counter-staining were performed on peripheral blood erythrocytes from Algerian mice to evaluate genotoxic damage. Animals were collected in four locations each differently affected by the disaster. Higher frequencies of micronuclei and CREST-positive micronuclei were observed in the sites, which were reached by toxic sludge and contaminated water in comparison with those located within the park. The results obtained applying the two methods indicate that DAPI staining is more sensitive in detecting micronuclei. Genotoxic biomonitoring should be further carried out in the area to control the mutagenetic level in natural populations

    Genotoxic damage in free-living Algerian mouse (Mus spretus) after the Coto Doñana ecological disaster

    No full text
    The Donana National Park (Spain), one of the most important wildlife sites in the West of Europe, was affected (25 April 1998) by the spill of acidic waste rich in toxic metals (mainly zinc, lead, copper, etc.), arsenic and aromatic amines from the Aznalcollar mine accident. Micronuclei test with May Grunwald-Giemsa and with CREST-antikinetocore staining using DAPI as counterstaining were performed on peripheral blood erythrocytes from Algerian mice to evaluate genotoxic damage. Animals were collected in four locations each differently affected by the disaster. Higher frequencies of micronuclei and CREST-positive micronuclei were observed in the sites, which were reached by toxic sludge and contaminated water in comparison with those located within the park. The results obtained applying the two methods indicate that DAPI staining is more sensitive in detecting micronuclei. Genotoxic biomonitoring should be further carried out in the area to control the mutagenetic level in natural populations. Copyright © 2001 Elsevier Science Ltd.Peer Reviewe

    25 Gb/s operation of 1-GHz bandwidth R-SOA by using DMT and optical equalization

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    We report the first experimental demonstration of 25Gb/s operation of 1GHz bandwidth-limited Reflective Semiconductor Optical Amplifier based on DMT modulation and optical equalization. This combination is highly resilient to chromatic dispersio
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