a b s t r a c tThe European Union's Marine Strategy Framework Directive (MSFD) seeks to achieve, for all European seas, "Good Environmental Status" (GEnS), by 2020. Ecological models are currently one of the strongest approaches used to predicting and understanding the consequences of anthropogenic and climate-driven changes in the natural environment. We assess the most commonly used capabilities of the modelling community to provide information about indicators outlined in the MSFD, particularly on biodiversity, food webs, non-indigenous species and seafloor integrity descriptors. We built a catalogue of models and their derived indicators to assess which models were able to demonstrate: (1) the linkages between indicators and ecosystem structure and function and (2) the impact of pressures on ecosystem state through indicators. Our survey identified 44 ecological models being implemented in Europe, with a high prevalence of those that focus on links between hydrodynamics and biogeochemistry, followed by end-to-end, species distribution/habitat suitability, bio-optical (remote sensing) and multispecies models. Approximately 200 indicators could be derived from these models, the majority of which were biomass and physical/hydrological/chemical indicators. Biodiversity and food webs descriptors, with ∼49% and ∼43% respectively, were better addressed in the reviewed modelling approaches than the non-indigenous species (0.3%) and sea floor integrity (∼8%) descriptors. Out of 12 criteria and 21 MSFD indicators relevant to the abovementioned descriptors, currently only three indicators were not addressed by the 44 models reviewed. Modelling approaches showed also the potential to inform on the complex, integrative ecosystem dimensions while addressing ecosystem fundamental properties, such as interactions between structural components and ecosystems services provided, despite the fact that they are not part of the MSFD indicators set. The cataloguing of models and their derived indicators presented in this study, aim at helping the planning and integration of policies like the MSFD which require the assessment of all European Seas in relation to their ecosystem status and pressures associated and the establishment of environmental targets (through the use of indicators) to achieve GEnS by 2020.

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To determine whether interferon alfa (IFN-␣) prevents in vivo oncogenesis in very-earlystage cancer cells, we evaluated the action of IFN-␣2b over preneoplastic foci in rats. Animals were divided into 6 groups: subjected to a 2-phase model (diethylnitrosamine [DEN] plus 2-acetylaminofluorene [2-AAF]) of preneoplasia development (group 1), treated with IFN␣2b during the 2 phases (group 2), only during initiation with DEN (group 3), only during administration of 2-AAF (group 4), subjected only to an initiation stage (group 5), and treated with IFN-␣2b during this period (group 6). The numbers of placental form of rat glutathione S-transferase (rGST-P)-positive foci per liver and the foci as percentage of liver were significantly reduced in groups 2, 3, and 6 but not in group 4. Rats treated with IFN-␣2b showed a higher apoptotic index (AI) in altered hepatic foci (AHF). Levels of p53 and Bax protein in liver lysates were significantly increased in those animals. Similarly, levels of antiapoptotic proteins Bcl-2 and Bcl-x L in mitochondrial fraction were decreased. Finally, increased levels of Bax protein were localized in the mitochondria of rats that received IFN-␣2b, at least during the DEN phase (groups 2, 3, and 6), whereas mitochondrial Bax expression was not increased in group 4. In conclusion, the preneoplastic hepatocytes in rats that received IFN-␣2b during the initiation stage undergo programmed cell death as a primary result of a significant increase in the amount and translocation to the mitochondria of Bax protein. (HEPATOLOGY 2002;35:824-833.)

Scope:Quercetin is the most abundant flavonoid in human diet. It has special interest as it holds anticancerous properties. This study aims to clarify the mechanisms involved in quercetin effects during the occurrence of preneoplastic lesions in rat liver. Methods and results: Adult male Wistar rats were subjected to a two-phase model of hepatocarcinogenesis (initiated-promoted group). Initiated-promoted animals also received quercetin 10 and 20 mg/kg body weight (IPQ10 and IPQ20 groups, respectively). Antioxidant defenses were modified by quercetin administration at both doses. However, only IPQ20 group showed a reduction in number and volume of preneoplastic lesions. This group showed increased apoptosis and a reduction in the proliferative index. In addition, IPQ20 group displayed a reduction of cell percentages in G 1 and S phases, accumulation in G 2 , and decrease in M phase, with reduced expression of cyclin D1, cyclin A, cyclin B, and cyclin-dependent kinase 1. Interestingly, peroxisome proliferator activated receptor-␣ levels were reduced in IPQ20 group. Conclusion: The outcomes of this study represent a significant contribution to the current understanding on the preventive mechanisms of quercetin during the early stages of liver cancer development, demonstrating that in addition to its known proapoptotic characteristics, the flavonoid modulates the expression of critical cell cycle regulators and peroxisome proliferator activated receptor-␣ activity.

El objetivo de este trabajo es discutir la relevancia de la localidad arqueológica Laguna de los Pampas en el estudio de las ocupaciones humanas del Campo de Dunas del Centro Pampeano (subregión Pampa Húmeda) durante el Holoceno. Un hallazgo relevante lo constituyen tres huevos de ñandú enteros y semienterrados, con perforaciones que sugieren su utilización como contenedor de líquido. Si bien la laguna fue habitada a lo largo del todo el Holoceno, las dataciones radiocarbónicas del sector excavado ubican a las ocupaciones humanas en el Holoceno medio (entre ca. 7000 y 5800 aP). Para este lapso se determinó que la explotación faunística estuvo orientada al consumo del guanaco, pero con un fuerte complemento de otros taxones como ñandú, venado de las Pampas y especies de menor tamaño. Se registró una tecnología ósea estandarizada sobre huesos de guanaco. Las rocas proceden principalmente del sistema serrano de Tandilia, aunque se identifican materias primas de otras áreas como el oeste pampeano. Las similitudes en las estrategias de producción y usos de los instrumentos con otros sitios de la subregión Pampa Húmeda sugieren el empleo de una misma concepción tecnológica a escala regional durante el Holoceno medio y la interacción con grupos cazadores-recolectores que ocupaban los pastizales pampeanos.