Preventing Additive Attacks to Relational Database Watermarking

False ownership claims are carried on through additive and invertibility attacks and, as far as we know, current relational watermarking techniques are not always able to solve the ownership doubts raising from the latter attacks. In this paper, we focus on additive attacks. We extend a conventional image-based relational data watermarking scheme by creating a non-colluded backup of the data owner marks, the so-called secondary marks positions. The technique we propose is able to identify the data owner beyond any doubt

Diet and feeding intensity of sardine Sardina pilchardus: correlation with satellite-derived chlorophyll data

Spatio-temporal variability of the diet of sardine Sardina pilchardus off Portugal was examined through analysis of the stomach contents of fish collected every 14 d from the west and south of Portugal during 2003/2004. Dietary composition of the modal sardine length class was assessed by determining the frequency of occurrence and carbon content of identified prey, and these 2 parameters were combined to estimate a modified index of relative importance of prey (mIRI). The most important prey for sardines were zooplankton, comprising crustacean eggs, copepods, decapods, cirripedes and fish eggs, dinoflagellates and diatoms (particularly the toxin-producer\ud genus Pseudo-nitzschia), which together accounted for >90% of the estimated dietary carbon. Dietary seasonality was similar for both areas, except that the contribution of phytoplankton was higher for fish from the west Portuguese coast, where upwelling events are stronger and recurrent during spring and summer months. The predominance of prey <750 μm in sardine diet suggests that filter feeding is the dominant feeding mode used in the wild. Feeding intensity was similar for both sexes and for fish of different length classes and was higher on the west coast than in the south, which is probably related to the higher productivity of the west coast. Although there was high inter-annual variability in feeding intensity, this parameter was highest for both areas during spring and winter months. Temporal variability in satellite-derived chlorophyll a matched the temporal variability in the dietary contribution by phytoplankton and of sardine feeding intensity, suggesting further investigation of the potential use of satellite-derived chlorophyll a data as a proxy for sardine feeding intensity

Restricted Application of Insecticides: A Promising Tsetse Control Technique, but What Do the Farmers Think of It?

Restricted application of insecticides to cattle is a cheap and safe farmer-based method to control tsetse and the diseases they transmit, i.e. human and animal African trypanosomoses. The efficiency of this new control method has been demonstrated earlier but no data is available on its perception and adoption intensity by farmers. We studied these two features in Burkina Faso, where the method has diffused thanks to two development projects. The study allowed identifying three groups of farmers with various adoption intensities, of which one was modern and two traditional. The economic benefit and the farmers' knowledge of the epidemiological system appeared to have a low impact on the early adoption process whereas some modern practices, as well as social factors appeared critical. The quality of technical support provided to the farmers had also a great influence on the adoption rate. The study highlighted individual variations in risk perceptions and benefits, as well as the prominent role of the socio-technical network of cattle farmers. The results of the study are discussed to highlight the factors that should be taken into consideration, to move discoveries from bench to field for an improved control of trypanosomoses vectors

Marine climate change risks to biodiversity and society in the ROPME Sea Area

The subtropical ROPME Sea Area (RSA), comprising the Gulf, the Gulf of Oman and the northern Arabian Sea, is a heavily exploited sea region that experiences extreme environmental conditions, and for which climate change is expected to further impact marine ecosystems and coastal communities, sectors and industries. Climate change risk assessments provide a valuable tool to inform decision-making and adaptation planning through identifying and prioritising climate risks and/or opportunities. Using the first UK Climate Change Risk Assessment as an example, a marine climate change risk assessment was undertaken for the marine and coastal environment of the RSA for the first time. Through an extensive literature review and a workshop involving regional experts, marine and coastal climate change risks were identified, scored and prioritised. A total of 45 risks were identified, which spanned two key themes: ‘Risks to Biodiversity’ and ‘Risks to Economy and Society’. Of these, 13 were categorised as ‘severe’, including degradation of coral reefs and their associated ecological assemblages, shifts in the distribution of wild-capture fisheries resources, changes to phytoplankton primary productivity, impacts on coastal communities, threats to infrastructure and industries, and impacts on operations and safety in maritime transport. The diversity of risks identified and their transboundary nature highlight that climate change adaptation responses will require coordinated action and cooperation at multiple scales across the RSA. This risk assessment provides a crucial baseline for a largely overlooked geographic area, that can be used to underpin future decision-making and adaptation planning on climate change, and serve as a ‘blueprint’ for similar assessments for other regional shared seas

Inequities and their determinants in coverage of maternal health services in Burkina Faso

Background: Poor and marginalized segments of society often display the worst health status due to limited access to health enhancing interventions. It follows that in order to enhance the health status of entire populations, inequities in access to health care services need to be addressed as an inherent element of any effort targeting Universal Health Coverage. In line with this observation and the need to generate evidence on the equity status quo in sub-Saharan Africa, we assessed the magnitude of the inequities and their determinants in coverage of maternal health services in Burkina Faso. Methods: We assessed coverage for three basic maternal care services (at least four antenatal care visits, facility-based delivery, and at least one postnatal care visit) using data from a cross-sectional household survey including a total of 6655 mostly rural, poor women who had completed a pregnancy in the 24 months prior to the survey date. We assessed equity along the dimensions of household wealth, distance to the health facility, and literacy using both simple comparative measures and concentration indices. We also ran hierarchical random effects regression to confirm the presence or absence of inequities due to household wealth, distance, and literacy, while controlling for potential confounders. Results: Coverage of facility based delivery was high (89%), but suboptimal for at least four antenatal care visits (44%) and one postnatal care visit (53%). We detected inequities along the dimensions of household wealth, literacy and distance. Service coverage was higher among the least poor, those who were literate, and those living closer to a health facility. We detected a significant positive association between household wealth and all outcome variables, and a positive association between literacy and facility-based delivery. We detected a negative association between living farther away from the catchment facility and all outcome variables. Conclusion: Existing inequities in maternal health services in Burkina Faso are likely going to jeopardize the achievement of Universal Health Coverage. It is important that policy makers continue to strengthen and monitor the implementation of strategies that promote proportionate universalism and forge multi-sectoral approach in dealing with social determinants of inequities in maternal health services coverage

Trust in Anonymity Networks

Anonymity is a security property of paramount importance, as we move steadily towards a wired, online community. Its import touches upon subjects as different as eGovernance, eBusiness and eLeisure, as well as personal freedom of speech in authoritarian societies. Trust metrics are used in anonymity networks to support and enhance reliability in the absence of verifiable identities, and a variety of security attacks currently focus on degrading a user's trustworthiness in the eyes of the other users. In this paper, we analyse the privacy guarantees of the \textsc{Crowds} anonymity protocol, with and without onion forwarding, for standard and adaptive attacks against the trust level of honest users

Vital rates of sardine and anchovy larvae: trying to shed new light on early life history dynamics

36th Annual Larval Fish Conference, 2-6 July 2012, Os, NorwayLaboratory experiments to study the vital rates of sardine (Sardina pilchardus) and anchovy (Engraulis encrasicolus) larvae in relation to differences in several key physical and biological factors considered most important for regulating their growth and survival, are being carried out in the framework of the project VITAL, financed by the Portuguese Foundation for Science and Technology (PTDC/MAR/111304/2009). The experiments aim at obtaining parameters such as the physiological tolerance limits of temperature, salinity and food availability for larvae survival and their influence on larval growth and ingestion rates. The nutritional condition of larvae reared in the laboratory is being monitored and compared with larvae collected in the wild, validating combined techniques (fatty acids and RNA/DNA). The quantitative estimates of the vital rates for the larvae of these fish species under controlled laboratory conditions will be used for parameterize an individual-based model to couple to a hydrodynamic model developed for the western Portuguese coast. Efforts to build models describing environmental regulation of small pelagic fish species (e.g., to examine links between climate and recruitment) are currently hampered by a lack of data such as the vital rates of the larval phase, to which we hope to contribute with our research. In this talk, we will present a synopsis of the results obtained so far for sardines, from adult fish collection and spawning initiation to the experiments of growth rates of sardine larvae under different prey regimes. Nearly 300 adult sardines were acclimated to a tank of the Oceanrio de Lisboa and since 2010 have spawned viable eggs for more than 200 days. Although there were no significant differences in egg size, the mean size of sardine larvae at hatch was significantly different amongst experiments (2.8 - 4.8 mm). Interestingly, in those experiments which had, on average, smaller larvae at hatch, the growth during the first week of life appeared to be higher than in experiments with larger larvae; early growth was significantly related to size-at-hatch until 9 dph, 5 days beyond the exogenous feeding initiation. The growth and survival for the remaining period of exogenous feeding was affected by food type and concentration. Highest growth and nutritional condition (RNA/DNA) of sardine larvae, growing up to 75 dph, were obtained using high concentrations of a mixed diet, combining Gymnodinium sp., rotifers and Acartia grani nauplii. This diet guaranteed higher growth and survival than a diet based on wild planktonPeer reviewe

The influence of different microalgal diets on European clam (Ruditapes decussatus, Linnaeus, 1758) larvae culture performances

The European clam, Ruditapes decussatus is a species with high commercial importance in Portugal and other Southern European countries. However, the development of R. decussatus culture has been limited by the highly variable patterns of natural recruitment. The development of hatchery technology will provide an alternative source of spat. The effect of six nutritional regimes on the survival, growth and biochemical composition of R. decussatus larvae were evaluated, aiming to provide crucial information on its nutritional requirements. A holistic approach incorporating all physiological response showed that the bispecific diet I. aff galbana and C. calcitrans (60/40 cell μL−1) was the more adapted throughout larval development. Moreover, the monospecific diet I. aff galbana provided an overall good performance. Larvae cannot use C. calcitrans at early stages of development; however, the inclusion of these microalgae improved late larval development. The results obtained constitute an important first step in the hatchery R. decussatus larval nutrition and a prerequisite for future work on the improvement of larval development and the optimization of feeding practices that will maximize larvae yield and minimize cost in aquaculture hatcheries.* REPROSEED (‘REsearch to improve PROduction of SEED of established and emerging bivalve species in European hatcheries’). Grant Number: FP7-KBBE-2009-3 * ‘Ciência 2007 Program