Excessive salt accumulation in soils is a major ecological and agronomical problem, in particular in arid and semiarid areas. While important physiological insights about the mechanisms of salt tolerance in plants have been gained, the transfer of such knowledge into crop improvement has been limited. The identification and exploitation of soil microorganisms (especially rhizosphere bacteria and mycorrhizal fungi) that interact with plants by alleviating stress opens new alternatives for a pyramiding strategy against salinity as well as
new approaches to discover new mechanisms involved in stress tolerance. Considering the kingdom of fungi, arbuscular mycorrhizal fungi (AMF) stand out as the most significant and widespread group of plant growth–promoting microorganisms. Ectomycorrhizal fungi (EMF) are also important symbionts of particular relevance for many woody plants. Considering the kingdom of bacteria, a wide range of microorganisms including different species and strains of Bacillus, Burkholderia, Pseudomonas, and the well-known nitrogen-fixing organisms
Rhizobium, Bradyrhizobium, Azotobacter, Azospirillum,
and Herbaspirillum are classically regarded as
important plant growth–promoting rhizobacteria
(PGPR). Today, it is widely accepted that
AMF, EMF, and PGPR promote plant growth and
increase tolerance against stress conditions, at
least in part, because they facilitate water and
nutrient uptake and distribution as well as alter
plant hormonal status, and this ability has been
attributed to various mechanisms. This chapter
addresses the significance of soil biota in alleviation
of salinity stress and their beneficial effects
on plant growth and productivity. Moreover,
it emphasizes new perspectives and challenges
in physiological and molecular studies on salt
stress alleviation by soil biota.

Abstract. Membrane Computing is an emergent and promising branch of Natural Computing. Designing P systems is heavy constitutes a difficult
problem. The candidate has often had an idea about the problem soluti onform. On the other hand, finding the exact and precise configurations
and rules is a hard task, especially if there is no tool used to help in the designing process. The clonal selection algorithm, which is inspired from
the vertebrate immune system, is introduced here to help in designing a P system that performs a specific task. This paper illustrates the use of
the clonal selection algorithm with adaptive mutation in P systems design and compares it with genetic algorithms previously used to achieve the
same purpose. Experimental results show that clonal selection algorithm surpasses genetic algorithms with a great difference.

Abstract. Membrane Computing is an emergent and promising branch of Natural Computing. Designing P systems is heavy constitutes a difficult
problem. The candidate has often had an idea about the problem soluti onform. On the other hand, finding the exact and precise configurations
and rules is a hard task, especially if there is no tool used to help in the designing process. The clonal selection algorithm, which is inspired from
the vertebrate immune system, is introduced here to help in designing a P system that performs a specific task. This paper illustrates the use of
the clonal selection algorithm with adaptive mutation in P systems design and compares it with genetic algorithms previously used to achieve the
same purpose. Experimental results show that clonal selection algorithm surpasses genetic algorithms with a great difference.

The objectives of this paper are representing a simulator for the logic gates using P systems with priorities
rules, and making use of the P system parallel computing in order to reduce the time used to test or evaluate a logic circuit (set of logic gates), which may change the vision of the current logic gates systems. Also, introducing the basic logic gates and how they work together, the development of the appropriate P system models for these gates are represented, and putting all together in order to get logic circuits which are P system based, finally a simulation and a test for them using a P Lingua language simulator, and an example is introduced to illustrate and making test of the model.

BACKGROUND: P-glycoprotein (P-gp) is a membrane efflux pump which is overexpressed in Chronic Rhinosinusitis with Nasal Polyps (CRSwNP) and promotes Type 2 inflammation. Glucocorticoids (GC) are substrates of P-gp suggesting that overexpression may additionally contribute to GC resistance in CRSwNP. This study aims to determine whether P-gp inhibition using verapamil enhances mometasone retention and efficacy in nasal polyp explants.

METHODOLOGY: IRB approved study in which organotypic polyp explants were exposed to mometasone (4.15 μg/mL) and verapa- mil (125 μg/mL) as mono and combination therapy. The effect of verapamil on mometasone tissue retention over time was deter- mined using HPLC. The effect of verapamil on mometasone anti-inflammatory function was determined using ELISA for secreted IL-5. Groups were compared using Kruskal-Wallis test.

RESULTS: P-gp expression strongly and significantly inversely correlated with mometasone retention 1hr after exposure, with a ne- arly 6-fold reduction in tissue retention between the lowest and highest P-gp expressing polyp explants. P-gp inhibition reversed this effect and significantly improved mometasone retention at 1hr relative to mometasone alone. The combination of mome- tasone and verapamil significantly reduced IL-5 secretion relative to vehicle control and outperformed either treatment alone.

CONCLUSIONS: Our study confirms that P-gp contributes to mometasone resistance. This P-gp mediated resistance was successfully reversed by addition of the P-gp inhibitor verapamil. Verapamil further significantly enhanced the anti-inflammatory effect of mometasone when given as a combination therapy.

Resistance of solid tumors to treatment is significantly attributed to pharmacokinetic reasons at both cellular and multi-cellular levels. Anticancer agent must be bio-available at the site of action in a cytotoxic concentration to exert its proposed activity. P-glycoprotein (P-gp) is a member of the ATP-dependent membrane transport proteins; it is known to pump substrates out of cells in ATP-dependent mechanism. The over-expression of P-gp in tumor cells reduces the intracellular drug concentrations, which decreases the cytotoxicity of a broad spectrum of antitumor drugs. Accordingly, P-gp inhibitors/blockers are potential enhancer for the cellular bioavailability of several clinically important anticancer drugs such as, anthracyclines, taxanes, vinca alkaloids, and podophyllotoxins. Besides several chemically synthesized P-gp inhibitors/blockers, some naturally occurring compounds and plant extracts were reported for their modulation of multidrug resistance; however, this review will focus only on major classes of naturally occurring inhibitors viz., flavonoids, coumarins, terpenoids, alkaloids and saponins.