4 research outputs found
Survey of fish species from plateau streams of the Miranda River Basin in the Upper Paraguay River Region, Brazil
To connect or not to connect?: floods, fisheries and livelihoods in the Lower Rufiji floodplain lakes, Tanzania
For seven years, village-based recorders monitored fish catches and water levels in seven floodplainassociated
lakes of the Lower Rufiji, Tanzania. The lakes differ in the number of days and volume of inflows from
the river, and thus provide a natural experiment to explore the links between catch composition, income per hour of
fishing (IPHF) and hydrological connectivity, and to analyse the response of the users. The fishers adapt their fishing
mode and equipment to achieve a rather constant IPHF of between 0.2 and 0.8 US$/fisher/hour. In situations
of low connectivity, during a series of drought years, the less well-connected lakes lost many species and became a
virtual monoculture of Oreochromis urolepis. Only in one extreme case was average fish size significantly reduced,
indicating a high fishing pressure. Catch was therefore highly resilient to shifts toward illegal, non-selective and
active fishing techniques. Fish diversity and lake productivity were quickly re-established when the larger lakes
reconnected. The potential impacts of changes in the flood hydrograph (through dams, increased abstraction or
climate/land-use changes) are assessed, and management options discussed
The CYGNO Experiment
The search for a novel technology able to detect and reconstruct nuclear and electron recoil events with the energy of a few keV has become more and more important now that large regions of high-mass dark matter (DM) candidates have been excluded. Moreover, a detector sensitive to incoming particle direction will be crucial in the case of DM discovery to open the possibility of studying its properties. Gaseous time projection chambers (TPC) with optical readout are very promising detectors combining the detailed event information provided by the TPC technique with the high sensitivity and granularity of latest-generation scientific light sensors. The CYGNO experiment (a CYGNus module with Optical readout) aims to exploit the optical readout approach of multiple-GEM structures in large volume TPCs for the study of rare events as interactions of low-mass DM or solar neutrinos. The combined use of high-granularity sCMOS cameras and fast light sensors allows the reconstruction of the 3D direction of the tracks, offering good energy resolution and very high sensitivity in the few keV energy range, together with a very good particle identification useful for distinguishing nuclear recoils from electronic recoils. This experiment is part of the CYGNUS proto-collaboration, which aims at constructing a network of underground observatories for directional DM search. A one cubic meter demonstrator is expected to be built in 2022/23 aiming at a larger scale apparatus (30 m3-100 m3) at a later stage