Positivity of solutions to boundary value problems for infinite functional differential systems

In this paper the problems of unique solvability of boundary value problems for infinite functional differential systems and positivity of their solutions are reduced to analysis of scalar functional equations in the space of measurable essentially bounded functions y:[0,+∞)→(−∞,+∞). Efficient tests of the solvability and the positivity are obtained.     

Contact orderability up to conjugation

We study in this paper the remnants of the contact partial order on the orbits of the adjoint action of contactomorphism groups on their Lie algebras. Our main interest is a class of noncompact contact manifolds, called convex at infinity.     

Application of the modified polarographic Brdička method for cancer testing

This paper reviews the application of a modification of the polarographic Brdi?ka method for cancer testing. The modification comprises the catalytic electroreduction of metal ions (here called Brdi?ka method based on catalytic metal ion reduction for cancer testing—BMMCT) and/or the electrooxidation of proteins, instead of the classical approach based on the catalytic electroreduction of protons, i.e., hydrogen waves (here called Brdi?ka method based on catalytic hydrogen evolution for cancer testing—BMHCT). Further, in the modified method, the mercury electrode has been replaced by a nontoxic solid electrode and the entire measuring system has been automated. The modified method excels in improved testing rates and sensitivity of cancer testing. The cancer testing of vaginal secretions is characterized by high specificity as well.     

Three sources of CO2 efflux from soil partitioned by 13C natural abundance in an incubation study

This study describes a novel approach to separate three soil carbon (C) sources by one tracer method (here 13C natural abundance). The approach is based on the combination of C3 and C4 sources in different treatments, identical decomposition of C3 and C4 substances in soil, and subsequent calculation of their contribution to the total CO2 efflux. We used the temporal dynamics of the CO2 efflux from a C3 grassland soil amended with added C3 or C4 slurry and/or C3 or C4 sugar to estimate contributions of three separate C sources: native soil organic matter (SOM), slurry and sugar, to CO2 efflux. Soil with slurry and/or sugar was incubated under controlled conditions, and concentration and delta13C values of evolved CO2 were measured over a 2-week period. The main assumption needed for separation of three C sources in CO2 efflux, i.e. identical decomposition of applied C3 and C4 sugars in soil, was investigated and proven. The relative contribution to the CO2 efflux increased, but its duration decreased with an increased microbial availability of the C source, i.e. sugar > slurry > SOM. The microorganisms used the C sources according to their availability. The contribution of sugar to the CO2 efflux was finished after 2-4 days. Separation of three CO2 sources and comparison of CO2 from different treatments tracing the changes of SOM and slurry decomposition induced by addition of sugar were investigated. During the sugar decomposition (the first 2-4 days), the SOM decomposition strongly decreased. At the same time the contribution of slurry-C to CO2 increased. The shortcomings and limitations as well as possible future applications of the suggested method including FACE (Free Air Carbon dioxide Enrichments) and continuous labelling experiments are discussed.