ABSTRACT
We solve MacArthur's resource-competition model with random species-resource couplings in the "thermodynamic" limit of infinitely many species and resources using dynamical path integrals à la De Domincis. We analyze how the steady state picture changes upon modifying several parameters, including the degree of heterogeneity of metabolic strategies (encoding the preferences of species) and of maximal resource levels (carrying capacities), and discuss its stability. Ultimately, the scenario obtained by other approaches is recovered by analyzing an effective one-species-one-resource ecosystem that is fully equivalent to the original multi-species one. The technique used here can be applied for the analysis of other model ecosystems related to the version of MacArthur's model considered here.
Subject(s)
EcosystemABSTRACT
Determination of HER-2 status is an essential prerequisite in considering a patient's eligibility for anti-HER-2 therapy; few studies have focused on its evaluation on cytological material. We present a new method of assessing HER-2 status on cytological samples, by fluorescence in situ hybridization (FISH) with an automated detection system, using fresh frozen (FF) and May-Grunwald-Giemsa (MGG) stained smears, and we evaluate the reliability of HER-2 determination on fine needle aspiration cytology (FNAC). The pre-treatment protocol for FF smears is easier and faster than for MGG stained slides. However, with the described procedure, FISH is also feasible on archival MGG stained slides. We conclude that with this method, cytological samples obtained by FNAC, either FF or MGG, are a reliable option for assessing HER-2 status.
