The treatment regimes differed in the proportion
of the ditch (0, 33, 67, and 100% of surface area) that was sprayed to reach a lufenuron concentration of 3 mu g/L in the water column of the sprayed ditch section. The magnitude and duration of effects on macroinvertebrates, and on arthropods in particular, were higher when a larger proportion of the ditch was treated. Initially, more pronounced responses were observed for bivoltine and multivoltine insects and macrocrustaceans than for univoltine and semivoltine arthropods. Most macroinvertebrate arthropods showed delayed responses, with maximum treatment-related effects observed two to six weeks after lufenuron application. This latency of effects can be explained by the mode of action of lufenuron, involving inhibition of chitin synthesis, selleck compound which affects arthropod molting and metamorphosis. The observed effects were short-lived only in those ditches where 33% of the surface area was sprayed. In the ditches where 67 and 100% of the surface area was sprayed, some insects and macrocrustaceans showed long-term effects. In the 100% sprayed ditches in particular, selleck chemical the treatment-related reduction in arthropods resulted in indirect effects, such as an increase in snails, and later in an increase in the ephemeropteran Cloeon dipterum, probably because of an increase in periphyton, and release from competition and predation. Effects that
are most likely indirect BMS-754807 also were observed for Oligochaeta, Hirudinea, and the flatworm Mesostoma sp.”
“We developed a configurable model of single photon avalanche diodes (SPAD) array photodetectors with intelligent control and active quenching. In this model individual components can be simulated independently and subsequently linked to provide the overall detector response. The model enables the simulation of the entire detector and analysis of performance, including photon detection efficiency, timing and energy resolution. It can be used to optimize detector performance for specific applications, such as positron emission tomography (PET). The simulator consists of multiple configurable and interchangeable modules to model the array geometry as well as physical and optical
characteristics based on physical models and statistical equations. Readout electronics are also simulated in an algorithmic form. Monte Carlo simulations are used to model the 511 keV annihilation photon interactions and the optical photon transport in the scintillator, as well as carrier random walk in the silicon. Different methods to extract information from the digital output signal can be investigated. The simulator paves the way to the developement of new algorithms to extract relevant information in PET, but also for other applications such as Cerenkov radiation and fluorescence microscopy. Simulation results for photon detection efficiency, energy resolution and timing resolution are reported, showing the functionality of the simulator.