Motivating participation in social computing applications: a user modeling perspective

The explosive growth of Web-based social applications over the last 10?years has led people to engage in online communities for various purposes: to work, learn, play, share time and mementos with friends and family and engage in public action. Social Computing Applications (SCA) allow users to discuss various topics in online forums, share their thoughts in blogs, share photos, videos, bookmarks, and connect with friends through social networks. Yet, the design of successful social applications that attract and sustain active contribution by their users still remains more of an art than a science. My research over the last 10?years has been based on the hypothesis that it is possible to incorporate mechanisms and tools in the design of the social application that can motivate users to participate, and more generally, to change their behavior in a desirable way, which is beneficial for the community. Since different people are motivated by different things, it can be expected that personalizing the incentives and the way the rewards are presented to the individual, would be beneficial. Also since communities have different needs in different phases of their existence, it is necessary to model the changing needs of communities and adapt the incentive mechanisms accordingly, to attract the kind of contributions that are beneficial. Therefore User and Group (Community) Modeling is an important area in the design of incentive mechanisms. This paper presents an overview of different approaches to motivate users to participate. These approaches are based on various theories from the area of social psychology and behavioral economics and involve rewards mechanisms, reputation, open group user modeling, and social visualization. Future trends are outlined towards convergence with the areas of persuasive systems design, adaptive/personalized systems, and intelligent social learning environments.     

Modeling the efficacy of persuasive strategies for different gamer types in serious games for health

Persuasive games for health are designed to alter human behavior or attitude using various Persuasive Technology (PT) strategies. Recent years have witnessed an increasing number of such games, which treat players as a monolithic group by adopting a one-size-fits-all design approach. Studies of gameplay motivation have shown that this is a bad approach because a motivational approach that works for one individual may actually demotivate behavior in others. In an attempt to resolve this weakness, we conducted a large-scale study on 1,108 gamers to examine the persuasiveness of ten PT strategies that are commonly employed in persuasive game design, and the receptiveness of seven gamer personalities (gamer types identified by BrianHex) to the ten PT strategies. We developed models showing the receptiveness of the gamer types to the PT strategies and created persuasive profiles, which are lists of strategies that can be employed to motivate behavior for each gamer type. We then explored the differences between the models and, based on the results, proposed two approaches for data-driven persuasive game design. The first is the one-size-fits-all approach that will motivate a majority of gamers, while not demotivating any player. The second is the personalized approach that will best persuade a particular type of gamer. We also compiled a list of the best and the worst strategies for each gamer type. Finally, to bridge the gap between game design and PT researchers, we map common game mechanics to the persuasive system design strategies.     

On‐site wastewater treatment using reactive filter media

The aim of this study is to reduce the phosphate concentration in treated wastewater using a small amount of the reactive filter media, Filtralite P. Biologically treated wastewater was passed through a filter with 215 g of Filtralite P. In the laboratory, the phosphate removal efficiency was 51% at a flow speed of 0.87 m/h. Under real conditions, in an experimental stand filled with 0.5 m³ of Filtralite P, the phosphate removal efficiency was 85% and the removal efficiency of total suspended solids was 57% after a 5‐month period. The residual phosphate concentration in the filtrate from the experimental stand was 1 mg/L of PO₄‐P after the 5‐month period. The experimental filtration plant was buried in the ground, and it did not freeze and worked well under winter conditions. The results of this study can be useful in the design and development of tertiary wastewater treatment plants in view of their sustainability potential.     

Genetic Background of Fetal Growth Restriction

Fetal growth restriction (FGR) is one of the most formidable challenges in present-day antenatal care. Pathological fetal growth is a well-known factor of not only in utero demise in the third trimester, but also postnatal morbidity and unfavorable developmental outcomes, including long-term sequalae such as metabolic diseases, diabetic mellitus or hypertension. In this review, the authors present the current state of knowledge about the genetic disturbances responsible for FGR diagnosis, divided into fetal, placental and maternal causes (including preeclampsia), as well as their impact on prenatal diagnostics, with particular attention on chromosomal microarray (CMA) and noninvasive prenatal testing technique (NIPT).     

Curcumin Loaded Nanocarriers with Varying Charges Augmented with Electroporation Designed for Colon Cancer Therapy

(1) Background: The size and surface charge are the most significant parameters of nanocarriers that determine their efficiency and potential application. The poor cell uptake of encapsulated drugs is the main limitation in anticancer treatment. The well-defined properties of nanocarriers will enable to target specific tissue and deliver an active cargo. (2) Methods: In the current study, poly(D,L -lactide) (PLA) nanocarriers loaded with curcumin (CUR) and differing surface charge were evaluated for transport efficacy in combination with electroporation (EP) in dependence on the type of cells. The obtained CUR-loaded nanoparticles with diameters ranging from 195 to 334 nm (derived from dynamic light scattering (DLS)) were characterized by atomic force microscopy (AFM) (morphology and shape) and Doppler electrophoresis (ζ-potential) as well as UV-vis spectroscopy (CUR encapsulation efficiency (about 90%) and photobleaching rate). The drug delivery properties of the obtained PLA nanocarriers enhanced by electroporation were assessed in human colon cancer cells (LoVo), excitable normal rat muscle cells (L6), and free of voltage-gated ion channels cells (CHO-K1). CLSM studies, viability, and ROS release were performed to determine the biological effects of nanocarriers. (3) Results: The highest photodynamic activity indicated anionic nanocarriers (1a) stabilized by C₁₂(COONa)₂ surfactant. Nanocarriers were cytotoxic for LoVo cells and less cytotoxic for normal cells. ROS release increased in cancer cells with the increasing electric field intensity, irradiation, and time after EP. Muscle L6 cells were less sensitive to electric pulses. (4) Conclusions: EP stimulation for CUR-PLA nanocarriers transport was considered to improve the regulated and more effective delivery of nanosystems differing in surface charge.     

Studies of the antenna effect in polymer molecules. 29. Synthesis and properties of poly[sodium styrene sulfonate-co-(4-acryolyloxyphenyl)-10,15,20-tritolylporphyrin] in aqueous solution

The novel water soluble antenna polyelectrolyte: poly[sodium styrene sulfonate-co-(4-acryolyloxyphenyl)-10,15,20-tritolylporphyrin] (PSSS-Po) was synthesised, and its photophysical and photochemical properties were studied. Solubilisation of the various molecular probes such as pyrene or perylene in aqueous solution of the PSSS-Po proved that the polymer chain adopts the compact conformation. The interior of the polymer pseudomicelle is significantly less polar than water. The effective quenching of polymeric porphyrin fluorescence by sulfopropyl viologen (SPV) can be explained considering the possibility of electron transfer from the singlet-excited state of Po to SPV. This has been supported by measuring an absorption spectrum for PSSS-Po/SPV system after selective irradiation of Po chromophores. The formation of the new absorption bands characteristic for SPV⁻ radical anion indicated that the charge separation was achieved in that system.     

“Smart” polymeric nanospheres as new materials for possible biomedical applications

Novel random terpolymers of N-isopropylacrylamide (NIPAM), sodium 2-acrylamido-2-methyl-1-propanesulfonate (AMPS), and cinnamoyloxyethylmethacrylate (CEMA) were synthesized by free radical copolymerization using AIBN as an initiator. Five terpolymers were obtained by copolymerization of the monomer mixtures containing a fixed amount of 10 mol % of AMPS while the content of CEMA ranged from 5 to 25 mol % and was changed in 5 mol % increments. The terpolymers obtained are water-soluble. Because of their amphiphilic nature they undergo self-organization in the aqueous solution with the formation of micelles capable of solubilizing sparingly water soluble organic compounds, such as drugs. The terpolymers are susceptible to three external stimuli, i.e. temperature, ionic strength and UV light. Due to the presence of NIPAM in the terpolymers they display the lower critical solution temperature (LCST), the presence of AMPS makes them sensitive to the ionic strength of the solution, while the light-responsiveness of the terpolymers is due to the presence of cinnamoyl chromophores, which undergo photodimerization when irradiated with UV light at about 280 nm. Application of any of these stimuli alone or in combination with other stimuli allows changing the copolymer properties in a controlled way.     

Bacterial flora in chronic inner ear infections in adults

The human genome carries multiple copies of sequences related to endogenous retroviral DNA. We report here the distribution of a new multicopy long terminal repeat (LTR) sequence that has been a part of an endogenous retrovirus-like sequence RTVL-H2. Twenty-four human chromosomes were either separated by flow sorting or by using rodent cells carrying a single human chromosome, and the DNA was subjected to Southern analyses using the RTVL-H2 DNA as a probe. The RTVL-H2 LTRs were distributed among all the human chromosomes, but the density and the profile differed from chromosome to chromosome. The same chromosome obtained from different individuals showed essentially the same chromosome-specific patterns. The distribution of the RTVL-H2 LTRs among different chromosomes did not correlate with the distribution of LTRs from another endogenous retroviral DNA, HERV-A, strongly suggesting that there is no preferred chromosome or a region thereof, for the integration. The possibility of rearrangement or amplification after integration is discussed.