"Exhibitionists" and "voyeurs" do it better: A shared environment for flexible coordination with tacit messages

Coordination between multiple autonomous agents is a major issue for open multi-agent systems. This paper proposes the notion of Behavioural Implicit Communication (BIC) originally devised in human and animal societies as a new and critical coordination mechanism also for artificial agents. BIC is a parasitical form of communication that exploits both some environmental properties and the agents? capacity to interpret their actions. In this paper we abstract from the agents? architecture to focus on the interaction mediated by the environment. Observability of the environment ? and in particular of agents? actions ? is crucial for implementing BIC-based form of coordination in artificial societies. Accordingly in this paper we introduce an abstract model of environment providing services to enhance observation power of agents, enabling BIC and other form of observation-based coordination. Also, we describe a typology of environments and examples of observation based coordination with and without implicit communication

Characterisation and Skin Distribution of Lecithin-Based Coenzyme Q10-Loaded Lipid Nanocapsules

The purpose of this study was to investigate the influence of the inner lipid ratio on the physicochemical properties and skin targeting of surfactant-free lecithin-based coenzyme Q10-loaded lipid nanocapsules (CoQ10-LNCs). The smaller particle size of CoQ10-LNCs was achieved by high pressure and a lower ratio of CoQ10/GTCC (Caprylic/capric triglyceride); however, the zeta potential of CoQ10-LNCs was above /− 60 mV/ with no distinct difference among them at different ratios of CoQ10/GTCC. Both the crystallisation point and the index decreased with the decreasing ratio of CoQ10/GTCC and smaller particle size; interestingly, the supercooled state of CoQ10-LNCs was observed at particle size below about 200 nm, as verified by differential scanning calorimetry (DSC) in one heating–cooling cycle. The lecithin monolayer sphere structure of CoQ10-LNCs was investigated by cryogenic transmission electron microscopy (Cryo-TEM). The skin penetration results revealed that the distribution of Nile red-loaded CoQ10-LNCs depended on the ratio of inner CoQ10/GTCC; moreover, epidermal targeting and superficial dermal targeting were achieved by the CoQ10-LNCs application. The highest fluorescence response was observed at a ratio of inner CoQ10/GTCC of 1:1. These observations suggest that lecithin-based LNCs could be used as a promising topical delivery vehicle for lipophilic compounds

Berberine modulates expression of mdr1 gene product and the responses of digestive track cancer cells to Paclitaxel

Berberine is the major constituent of Coptis chinese and is commonly used in Chinese herbal medicine to treat patients with gastrointestinal disorders. In this study, using flow cytometry, we have found that a 24-h berberine treatment up-regulated the multidrug-resistant transporter (pgp-170) expression in two oral (KB, OC2), two gastric (SC-M1, NUGC-3) and two colon (COLO 205, CT 26) cancer cell lines. Decreased retention of rhodamine 123 was observed in berberine-treated cells as compared to vehicle control. To examine whether the berberine modulated pgp-170 expression in cancer cells is associated with changes in drug resistance, we determined the cytotoxicity, cell cycle progression and cell morphology of Paclitaxel-treated cells. Paclitaxel (1 nM–10 μM) treatment for 24 h induced cytotoxicity in OC2, SC-M1 and COLO 205 cells in a dose-dependent manner. Pretreatment of cells with 32 μM berberine for 24 h prior to Paclitaxel treatment resulted in increased viability as compared to that of Paclitaxel-treated cells. In addition, Paclitaxel-induced apoptosis and/or G2/M arrest in these three cancer cell lines. Pretreatment of cells with berberine prior to Paclitaxel blocked the Paclitaxel-induced cell cycle responses and morphological changes. These results together suggest that berberine modulated the expression and function of pgp-170 that leads to reduced response to Paclitaxel in digestive track cancer cells. © 1999 Cancer Research Campaig

Impaired bone and muscle development in young people treated with antiepileptic drugs

Objective: Antiepileptic drugs (AEDs) are associated with reduced bone density, balance impairment, and increased fracture risk in adults. However, pediatric data are limited. Therefore, we aimed to examine bone, muscle, and balance outcomes in young patients taking AEDs. Methods: We undertook a case–control study utilizing an AED exposure–discordant matched‐pair approach. Subjects were aged 5–18 years with at least 12 months of AED exposure. Pairs were twins, nontwin siblings and first cousins, sex‐ and age‐matched (to within 2 years), allowing for greater power than with unrelated control subjects. Dual energy x‐ray absorptiometry (DXA), peripheral quantitative computed tomography (pQCT), and muscle force/balance were tested, with questionnaires were administered for bone health and epilepsy details. Results: Twenty‐three pairs were recruited, (median age 12.9 years [subjects] and 13.5 years [controls])—7 twin, 14 sibling, and 2 cousin pairs. Those taking AEDs had an increased prevalence of fractures (15 fractures in 8 subjects, compared with 4 fractures in 3 controls, p < 0.01). Trabecular volumetric bone mineral density (vBMD) measured by pQCT at the 4% site (tibia) was reduced by 14% (p = 0.03) in subjects. Subjects exerted a decreased maximum force compared to body weight (Fmax total/g) at the tibia. There were no differences seen in either bone mineral parameters measured by DXA or balance measures. Significance: Young people taking AEDs reported more fractures and had reductions in tibial vBMD and lower limb muscle force compared to their matched controls. These findings suggest that further exploration of bone health issues of young patients on AED therapy is required. Longitudinal studies are required to confirm these changes in the muscle–bone unit and to further explore the clinical outcomes

Physicochemical Characteristics, Cytotoxicity, and Antioxidant Activity of Three Lipid Nanoparticulate Formulations of Alpha-lipoic Acid

Exogenously supplied alpha-lipoic acid (LA) has proven to be effective as an antioxidant. In an effort to develop a water-soluble formulation for topical administration, LA was formulated in the form of solid lipid nanoparticles (SLN), nanostructure lipid carriers (NLC), and nanoemulsion (NE) and characterized in terms of physical and biological properties. Mean particle size of 113, 110, and 121 nm were obtained for NE, NLC, and SLN, respectively, with narrow size distribution. Zeta potential was approximately in the range of −25 to −40 mV. Disc and spherical structures of nanoparticles were observed by cryo-scanning electron microscopy. Entrapment efficiency of LA in three formulations was found to be more than 70%. After 120 days of storage at 25°C, physical stability of all formulations remained unchanged whereas the entrapment efficiency of SLN and NLC could be maintained, suggesting relative long-term stability. Prolonged release of LA formulation following the Higuchi model was found where a faster release was observed from NE compared with that of SLN and NLC. More than 80% of cell survivals were found up to 1 μM of LA concentrations. Antioxidant activity analysis demonstrated that all LA-loaded formulations expressed antioxidant activity at a similar magnitude as pure LA. These results suggest that chosen compositions of lipid nanoparticles play an important role on drug loading, stability, and biological activity of nanoparticles. Both SLN and NLC demonstrated their potential as alternative carriers for aqueous topical administration of LA