An electronic clock for correlated noise corrections

An inexpensive and portable approach to measure the time an experimental event occurs as measured by a specific electronic clock is presented. The clock resets in active synchronization with the experimental AC-power cycle. This allows an efficient and complete correction for correlated noise contributions to pulse area and time measurements of detector channels equipped with PhotoMultiplier Tubes. The electronic board that was developed will be described. The performance for the treatment of correlated noise in experimental data taken at the BNL-AGS facility, and analyses of spectral decompositions of this noise, will also be described.Comment: 15 pages, 11 figures, submitted to Nucl Inst Methods Section A (8/25/99

Is the Gulf of Cadiz ready for the ecosystem approach? A perspective from the southernmost European Atlantic regional sea

This study considers the major milestones in history, current situation and prospects of developing an ecosystem approach to management in the Gulf of Cadiz ecosystem. This particular socio-ecosystem is characterised by a clear focal ecosystem component –the role of the estuary of the Guadalquivir River as a nursery area– that have an influence on the marine ecosystem and at the same time concentrates a great number of sectoral human activities. This nursery role particularly affects the anchovy fishery, which is the most economically and culturally important fishery in the region. As a transition zone between river and marine environments, estuaries are particularly sensitive to human activities, either developed directly at the aquatic environment and its surroundings or far upstream within its catchment area. The particularities of the Guadalquivir socio-ecosystem, with an area of influence that extend as far as the city of Seville, require the consideration of multiple sectors and corresponding conflicting interests. These comprise the shipping and touristic sectors, the agriculture and aquaculture industries, or the fisheries and conservation interests. Specifically, the aim of this work is to give an overview of the main components, actors, and challenges faced by this socio-ecological system. This includes: (1) describing the ecological characteristics and focal mechanisms, (2) the legislative framework and the responsible institutional bodies, (3) the involved sectors and their corresponding pressures, (4) identifying the institutional arrangements that could be potentially used to harmonize those conflicting interests and finally (5) a diagnose of the problems encountered when conflict has arisen that has so far blocked the development of an ecosystem approach in the region

the Gulf of Cadiz

CREAM projec

Spatio-temporal variability of the North Sea cod recruitment in relation to temperature and zooplankton

The North Sea cod (Gadus morhua, L.) stock has continuously declined over the past four decades linked with overfishing and climate change. Changes in stock structure due to overfishing have made the stock largely dependent on its recruitment success, which greatly relies on environmental conditions. Here we focus on the spatio-temporal variability of cod recruitment in an effort to detect changes during the critical early life stages. Using International Bottom Trawl Survey (IBTS) data from 1974 to 2011, a major spatio-temporal change in the distribution of cod recruits was identified in the late 1990s, characterized by a pronounced decrease in the central and southeastern North Sea stock. Other minor spatial changes were also recorded in the mid-1980s and early 1990s. We tested whether the observed changes in recruits distribution could be related with direct (i.e. temperature) and/or indirect (i.e. changes in the quantity and quality of zooplankton prey) effects of climate variability. The analyses were based on spatially-resolved time series, i.e. sea surface temperature (SST) from the Hadley Center and zooplankton records from the Continuous Plankton Recorder Survey. We showed that spring SST increase was the main driver for the most recent decrease in cod recruitment. The late 1990s were also characterized by relatively low total zooplankton biomass, particularly of energy-rich zooplankton such as the copepod Calanus finmarchicus , which have further contributed to the decline of North Sea cod recruitment. Long-term spatially- resolved observations were used to produce regional distribution models that could further be used to predict the abundance of North Sea cod recruits based on temperature and zooplankton food availability.Publicado

Electromagnetic Dissociation and Space Radiation

Relativistic nucleus-nucleus reactions occur mainly through the Strong or Electromagnetic (EM) interactions. Transport codes often neglect the latter. This work shows the importance of including EM interactions for space radiation applications.Comment: 11 page