PCBs and PAHs in sea-surface microlayer and sub-surfacewater samples of the Venice Lagoon (Italy)

Polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) are two classes of micropollutants intensively monitored and regulated due to their toxicity, persistency and wide diffusion. Their concentrations have been investigated in sea-microlayer (SML) and sub-surface water (SSW) samples collected at two sites of the Venice Lagoon, a fragile ecosystem highly influenced by industrial and anthropogenic emissions. The total PPCB concentration varies from 0.45 ng/l to 2.1 ng/l in SSW while a clear enrichment is observed in the SML, where it ranges from 1.2 ng/l to 10.5 ng/l. The total PPAH concentration shows marked differences between the two stations and varies from 12.4 ng/l to 266.8 ng/l in SSW; in SML it is more uniform and ranges from 19.6 ng/l to 178.9 ng/l. The enrichment factors are not larger than 1 for both pollutants in the dissolved phase, while they are most significant for the particulate phase (PPCB: 5–9; PPAH: 4–14). 2005 Elsevier Ltd. All rights reserved

Sequestration and Tissue Accumulation of Human Malaria Parasites: Can We Learn Anything from Rodent Models of Malaria?

The sequestration of Plasmodium falciparum–infected red blood cells (irbcs) in the microvasculature of organs is associated with severe disease; correspondingly, the molecular basis of irbc adherence is an active area of study. In contrast to P. falciparum, much less is known about sequestration in other Plasmodium parasites, including those species that are used as models to study severe malaria. Here, we review the cytoadherence properties of irbcs of the rodent parasite Plasmodium berghei ANKA, where schizonts demonstrate a clear sequestration phenotype. Real-time in vivo imaging of transgenic P. berghei parasites in rodents has revealed a CD36-dependent sequestration in lungs and adipose tissue. In the absence of direct orthologs of the P. falciparum proteins that mediate binding to human CD36, the P. berghei proteins and/or mechanisms of rodent CD36 binding are as yet unknown. In addition to CD36-dependent schizont sequestration, irbcs accumulate during severe disease in different tissues, including the brain. The role of sequestration is discussed in the context of disease as are the general (dis)similarities of P. berghei and P. falciparum sequestration

n-Alkanes, PAHs and surfactants in the sea surface microlayer and sea water samples of the Gerlache Inlet sea (Antarctica)

Sea surface microlayer (SML) and sea water samples (SSW) collected in the Gerlache Inlet Sea (Antarctica) were analysed for n-alkanes and polycyclic aromatic hydrocarbons (PAHs). The SML is a potential enrichment site of hydrophobic organic compounds compared to the underlying water column. Total concentration ranges of n-alkanes and PAHs (dissolved and particulate) in subsurface water (−0.5 m depth) were 272– 553 ng l−1 (mean: 448 ng l−1) and 5.27–9.43 ng l−1 (mean: 7.06 ng l−1), respectively. In the SML, the concentration ranges of n-alkanes and PAHs were 353–968 ng l−1 (mean: 611 ng l−1) and 7.32–23.94 ng l−1 (mean: 13.22 ng l−1), respectively. To evaluate possible PAH contamination sources, specific PAH ratios were calculated. The ratios reflected a predominant petrogenic input. A characterisation of surface active substances was also performed on SML and SSW samples, both by gas bubble extraction, and by dynamic surface tension measurements. Results showed a good correlation between n-alkanes, PAHs and refractory organic matter

The policy of the United States towards Cuba from 1989-1996

In the immediate post-Cold War period, as the security rationale for the U.S. embargo disappeared, the United States tightened rather than eased sanctions on Cuba. This dissertation focuses on the competition between Congress and the executive for control of policy towards Cuba, and the domestic interests which shaped policymaking and led to the passage of two major pieces of legislation fiercely resisted by U.S. allies. The dissertation begins with an analysis of U.S. policy towards Cuba in the summer of 1989, before the collapse of communism in Eastern Europe. Five days of congressional hearings called by Representative George Crockett (D.Michigan) in his attempt to spark a reassessment of relations between the two countries form the basis for a review of policy over the preceding thirty years. The first chapter will also introduce the Cuban American National Foundation, the pre-eminent domestic interest group in U.S. policy towards Cuba in 1989-1996, and the U.S. campaign to have Cuba condemned for human rights violations at the United Nations Human Right Commission. The second chapter examines the policy debate in 1989-1992, focusing on the provision of information to Cubans, the intensification of economic sanctions, and the continuation of the human rights campaign. The third chapter analyses the role of migration from Cuba to the United States between 1959-1992, arguing the main objective of U.S. policy. Chapter four looks at continuity and change under the Clinton administration, and in particular at the administration’s handling of the rafter (migration) crisis of 1994 and the resulting agreements reached with the Cuban government. The primary focus of the fifth chapter will be the struggle between the executive and Congress over the Helms-Burton legislation, signed by Clinton in March 1996.EThOS - Electronic Theses Online ServiceGBUnited Kingdo