Projection in surrogate decisions about life-sustaining medical treatments.

To honor the wishes of an incapacitated patient, surrogate decision makers must predict the treatment decisions patients would make for themselves if able. Social psychological research, however, suggests that surrogates' own treatment preferences may influence their predictions of others' preferences. In 2 studies (1 involving 60 college student surrogates and a parent, the other involving 361 elderly outpatients and their chosen surrogate decision maker), surrogates predicted whether a close other would want life-sustaining treatment in hypothetical end-of-life scenarios and stated their own treatment preferences in the same scenarios. Surrogate predictions more closely resembled surrogates' own treatment wishes than they did the wishes of the individual they were trying to predict. Although the majority of prediction errors reflected inaccurate use of surrogates' own treatment preferences, projection was also found to result in accurate prediction more often than counterprojective predictions. The rationality and accuracy of projection in surrogate decision making is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Microbial and toxic evaluation of raw and treated olive oil mill wastewaters

BACKGROUND: Olive oil mill wastewaters (OMW) from a three‐phase system were treated in a laboratory‐scale continuous stirred tank reactor (CSTR) for hydrogen production. Microbiological and physicochemical characterizations of raw and anaerobically treated olive oil mill effluents were performed. Toxicity assessment was also conducted in order to determine the impact of residual waters on the aquatic environment. RESULTS: Pseudomonas aeruginosa that has the ability to utilize phenolic compounds was isolated in raw OMW, along with several gram‐negative bacteria (Serratia odorifera, Enterobacter cloacae and Aeromonas hydrophila). The dominant species in the untreated effluent appears to be Enterobacter cloacae, whereas in the treated effluent it is Citrobacter braakii. Phenols, pH, NO^?₂, total dissolved solids (TDS) and conductivity were the main parameters related to the observed toxicity. CONCLUSION: A significant differentiation in the microbiological flora was detected between treated and untreated effluents whereas the microbial communities were correlated to the toxicity test results, pointing to the need for further research regarding identification of the microbial flora. This can improve the treatment processes to optimize management of OMW for environmentally safe discharge. Copyright © 2010 Society of Chemical Industry     

Stabilization of anthocyanin extract from jabuticaba skins by encapsulation using supercritical CO2 as solvent

Anthocyanins are one of most important group of water-soluble and vacuolar pigments in nature. This phytochemical has attracted great interest to the food industry due to the wide range of biological activities including antioxidant and anti-inflammatory activities. However, the introduction of anthocyanins into food and/or medical fields has proved to be a major technological challenge since these compounds have low stability to environmental conditions during processing and storage. In this context, the present study evaluates the encapsulation of anthocyanin extract obtained from jabuticaba (Myrciaria cauliflora) skins in Polyethyleneglycol using supercritical CO₂ as solvent and ethanol as co-solvent. For comparison, a conventional method, ionic gelification, was employed to produce encapsulated particles by entrapment in Ca-alginate beads. The encapsulation efficiency of the extract in Ca-alginate beads was higher (98.67%) than those obtained by Rapid Expansion of Supercritical Solution (RESS) process (79.78%). Encapsulated particles made by RESS at different pressures, and temperatures, retained the extracts' biological activity. The best operating RESS process condition for anthocyanin extract encapsulation was determined as 313.15 K and 20 MPa. The degradation studies indicated that both encapsulated systems were more stable to light and temperature than the free extract. Ca-alginate encapsulated Anthocyanin extract release in acid buffer solution was incomplete and slower than when the extract was encapsulated by PEG. Both systems increased the stability of anthocyanin, although presenting different characteristics.     

Bringing down the master's house with the master's tools

Abstract

Examples, illustrations, occurrences, and instances play a central role in the learning of mathematics. Deliberately getting students to generate examples is a particularly powerful tool in teaching, but, while some of the possibilities they offer are used by many teachers, their full potential is rarely exploited. The authors came to this notion through reflection on their experience of observing teachers in classrooms, of getting students to take initiatives, and of creating examples while working on their own mathematics. They examine the roles played by examples constructed and generated by students, give illustrations and analyses of the use of this tool, and develop a theory for the act of exemplification as an act of cognition. A framework is developed for researchers and practitioners to further this work.     

Understanding of visual attention by adult humans (Homo sapiens): A partial replication of Povinelli, Bierschwale, and ?ech (1999).

Povinelli, Bierschwale, and ?ech (1999) reported that when tested on a visual attention task, the behavior of juvenile chimpanzees did not support a high-level understanding of visual attention. This study replicates their research using adult humans and aims to investigate the validity of their experimental design. Participants were trained to respond to pointing cues given by an experimenter, and then tested on their ability to locate hidden objects from visual cues. Povinelli et al.'s assertion that the generalization of pointing to gaze is indicative of a high-level framework was not supported by our findings: Training improved performance only on initial probe trials when the experimenter's gaze was not directed at the baited cup. Furthermore, participants performed above chance on such trials, the same result exhibited by chimpanzees and used as evidence by Povinelli et al. to support a low-level framework. These findings, together with the high performance of participants in an incongruent condition, in which the experimenter pointed to or gazed at an unbaited container, challenge the validity of their experimental design. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Silver-containing mesoporous bioactive glass with improved antibacterial properties

The aim of the present work is the study of the bacteriostatic/bactericidal effect of a silver-containing mesoporous bioactive glass obtained by evaporation-induced self-assembly and successive thermal stabilization. Samples of the manufactured mesophase were characterized by means of transmission electron microscopy and N₂ adsorption/desorption at 77 K, revealing structural and textural properties similar to SBA-15 mesoporous silica. Glass samples used for bioactivity experiments were put in contact with a standardized, commercially available cell culture medium instead of lab-produced simulated body fluid, and were then characterized by means of X-ray diffraction, field emission scanning electron microscopy and Fourier transform infrared spectroscopy. All these analyses confirmed the development of a hydroxyl carbonate apatite layer on glass particles. Moreover, the investigated mesostructure showed a very good antibacterial effect against S. aureus strain, with a strong evidence of bactericidal activity already registered at 0.5 mg/mL of glass concentration. A hypothesis about the mechanism by which Ag affects the bacterial viability, based on the intermediate formation of crystalline AgCl, was also taken into account. With respect to what already reported in the literature, these findings claim a deeper insight into the possible use of silver-containing bioactive glasses as multifunctional ceramic coatings for orthopedic devices.     

Stability and change in patterns of concerns related to eating, weight, and shape in young adult women: A latent transition analysis.

Although college women are known to be at high risk for eating-related problems, relatively little is known about how various aspects of concerns related to eating, weight, and shape are patterned syndromally in this population. Moreover, the extent to which various patterns represent stable conditions or transitory states during this dynamic period of development is unclear. The present study used latent class and latent transition analysis (LCA/LTA) to derive syndromes of concerns related to eating, weight, and shape and movement across these syndromes in a sample of 1,498 women ascertained as first-time freshmen and studied over 4 years. LCA identified 5 classes characterized by (a) no obvious pathological eating-related concerns (prevalence: 28%–34%); (b) a high likelihood of limiting attempts (prevalence: 29%–34%); (c) a high likelihood of overeating and binge eating (prevalence: 14%–18%); (d) a high likelihood of limiting attempts and overeating or binge eating (prevalence: 14%–17%); and (e) pervasive bulimiclike concerns (prevalence: 6%–7%). Membership in each latent class tended to be stable over time. When movement occurred, it tended to be to a less severe class. These findings indicate that there are distinct, prevalent, and relatively stable forms of eating-related concerns in college women. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Linear Statistical Models

Risk assessment of rare natural hazards, such as large volcanic block and ash or pyroclastic flows, is addressed. Assessment is approached through a combination of computer modeling, statistical modeling, and extreme-event probability computation. A computer model of the natural hazard is used to provide the needed extrapolation to unseen parts of the hazard space. Statistical modeling of the available data is needed to determine the initializing distribution for exercising the computer model. In dealing with rare events, direct simulations involving the computer model are prohibitively expensive. The solution instead requires a combination of adaptive design of computer model approximations (emulators) and rare event simulation. The techniques that are developed for risk assessment are illustrated on a test-bed example involving volcanic flow.