Antioxidant and Antimicrobial Activity of Commercial Propolis Extract in Beef Patties

The objective of this study was to evaluate the efficacy of propolis extract (PE) to reduce lipid oxidation and microbial growth on beef patties during refrigerated storage. Beef patties were manufactured by incorporating PE in 4 different treatments: (1) Control (no PE addition); (2) commercial propolis 1 (2% w/w; CP1); (3) commercial propolis 2 (2% w/w; CP2); and (4) noncommercial propolis (2% w/w; NCP). Raw patties were wrapped with polyvinyl chloride and stored at 2 °C for 8 d. Total phenolic content (TPC), free‐radical scavenging activity (FRS), and polyphenolic content of the PE were evaluated using high‐performance liquid chromatography (HPLC). Lipid oxidation (thiobarbituric acid‐reactive substances (TBARS), conjugated dienes (CnDs), metmyoglobin (MetMb%), pH variation, and color (L*, a*, b*, C*, and h*), and microbial growth (mesophilic and psychrotrophic bacteria) of patty samples were measured. NCP treatment demonstrated the highest FRS (64.8% at 100 μg/mL), which correlated with TPC and the presence of polyphenolic compounds. Lipid oxidation (78.54%, TBARS; 45.53%, CnD; 58.57%, MetMb) and microbial mesophilic and psychrotrophic growth (19.75 and 27.03%, respectively) values were reduced by NCP treatment in refrigerated samples after 8 d. These results indicate that PE has great potential as a natural antioxidant and antimicrobial additive to extend the shelf life of beef patties.     

Evaluation of multi-attribute decision making systems applied during the concept design of new microplasma devices

Various multi-attribute decision making (MADM) systems can be implemented to narrow a field of new concept designs down to those with high likelihoods of surpassing state-of-the-art technologies. This research investigated the conceptual design phase of new microplasma devices in order to create metrics that evaluate the efficiency, effectiveness, and overall utility of representative MADM systems studied in previous engineering design applications. Device attributes and concept alternatives for the microplasma devices were identified from open-ended expert surveys. Efficiency metrics were defined based on the number of manual user inputs. Published device literature and testing were used to gauge how closely device concepts satisfied multi-attribute criteria, forming the basis of an effectiveness metric. A weighted average of the efficiency and effectiveness defined a MADM system’s overall utility. Varying the effectiveness weight provided further insight into the conditions under which particular MADM approaches exhibited higher utility values. The MADM systems found to possess the highest overall quantified utilities were based on Pugh’s controlled convergence, Utility Based Axiomatic Framework, and Grey Relational Analysis. The MADM method with the lowest overall utility was the analytical hierarchy process. These findings indicate that consensus building and utility-based MADM systems are especially helpful to engineering design teams during the early design phases of novel technologies when resources are constrained or historical data is limited.     

Comprehension of televised stories in boys with attention deficit/hyperactivity disorder and nonreferred boys.

Two studies compared comprehension of televised stories by 7- to 12-year-old boys with attention deficit/hyperactivity disorder (ADHD) and nonreferred comparison boys. Boys watched one show with toys present and one with toys absent. Visual attention was continuously recorded, and recall was tested after each show. Across studies, visual attention was high with toys absent but decreased sharply with toys present for boys with ADHD. Groups showed similar levels of cued recall of discrete units of information regardless of differences in attention. When recall tasks and television story structure required knowledge of relations among events, the reduced attention of boys with ADHD interfered with recall. Although visual attention of comparison boys also decreased to some extent with toys present, there was no such decrement in recall. Implications of the difficulties children with ADHD have in integrated story comprehension are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The computer simulation of microstructural evolution

This paper reviews the kinetic Monte Carlo Potts model for simulating microstructural evolution. When properly implemented, that model provides a fast and flexible tool for evaluating a variety of materials systems in two and three dimensions, generating snapshots of the evolving microstructure with time. Examples of the model are provided, along with potential applications. Editor’s Note: A hypertext-enhanced version of this article can be found at www.tms.org/pubs/journals/JOM/0109/Holm-0109.html. For more information, contact E.A. Holm, Sandia National Laboratories, Materials and Process Modeling, Albuquerque, NM 87185-1411; (505) 844-7669; fax (505) 844-9781; e-mail eaholm@sandia.gov.     

Synthesis, Phase Characterization, and Properties of Chemical Solution-Deposited Nickel Manganite Thermistor Thin Films

Nickel manganite spinel thin films prepared by chemical solution deposition exhibit negative temperature coefficient of resistance (TCR) values between −3.3 and −4.5%/K. In contrast to bulk thermistors, dense films could be prepared completely within the spinel phase field. Thus, decomposition into the NiO phase and a Mn-rich spinel, which is problematic in bulk ceramics, is minimized in thin films. For films prepared outside of the single-phase field, phase separation cannot always be detected using X-ray diffraction. In such cases, transmission electron microscopy is useful in identifying decomposition. It is found that the lattice parameters for films with compositions ranging between Mn/(Mn+Ni)=0.14 and 0.77 are smaller than the values reported for nickel manganite spinels, suggesting cation deficiency. Single-phase spinel films are compared with single-phase bixbyite films synthesized between 630° and 930°C. The bixbyite phase exhibits lower TCR and lower resistivity (TCR=−3.1 to −3.3%/K and resistivity values=400–1600 Ω·cm) compared with spinel (TCR=−3.6 to −4.1%/K and resistivity values=3500–21 000 Ω·cm). Composite films (achieved by controlling the pyrolysis to create a low local p O₂ during annealing) show intermediate values (TCR=−3.0 to −3.8%/K and resistivity values=470–6600 Ω·cm).     

Dream interpretation and false beliefs.

Dream interpretation is a common practice in psychotherapy. In the research presented in this article, each participant saw a clinician who interpreted a recent dream report to be a sign that the participant had had a mildly traumatic experience before age 3 years, such as being lost for an extended time or feeling abandoned by his or her parents. This dream intervention caused a majority of participants to become more confident that they had had such an experience, even though they had previously denied it. These findings have implications for the use of dream material in clinical settings. In particular, the findings point to the possibility that dream interpretation may have unexpected side effects if it leads to beliefs about the past that may, in fact, be false. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Synthesis and characterisation of magnetite nanoparticles using gelatin and starch as capping agents

Nanoparticles of magnetite passivated with gelatin and starch were synthesised using a co‐precipitation technique. The nanoparticles were characterised using ultraviolet–visible (UV–vis), dynamic light scattering (DLS), Zeta potential, transmission electron microscope (TEM), X‐ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The UV–vis spectra showed characteristic surface plasmon resonance of magnetite nanoparticles. The DLS results showed the nanoparticles to have average hydrodynamic diameters of 138 ± 2 and 283 ± 21 nm for particles passivated with gelatin and starch, respectively. The stability in a colloidal solution was greater in nanoparticles passivated with gelatin than nanoparticles obtained with starch, as can be seen by their Zeta potential value (−31 ± 2 and −16 ± 0.5 mV, respectively). According to the TEM evaluation, the use of gelatin allowed to obtain nanoparticles with a spherical morphology and an average size of 10 ± 2 nm. However, when using starch the nanoparticles exhibited diverse morphologies with an average size of 25 ± 7 nm. The XRD results confirmed the crystalline structure of the samples, which showed crystallite sizes of 14.90 and 24.43 nm for nanoparticles passivated with gelatin and starch, respectively. FTIR analysis proved the establishment of interactions between functional groups of biopolymers and magnetite nanoparticles.Inspec keywords: crystallites, nanofabrication, ultraviolet spectra, gelatin, surface plasmon resonance, transmission electron microscopy, scanning electron microscopy, visible spectra, X‐ray diffraction, iron compounds, electrokinetic effects, particle size, colloids, nanoparticles, nanomedicine, precipitation (physical chemistry), light scattering, magnetic particles, Fourier transform infrared spectra, nanomagnetics, filled polymers, nanocompositesOther keywords: magnetite nanoparticles, gelatin, starch, characteristic surface plasmon resonance, capping agents, passivation, co‐precipitation technique, ultraviolet–visible spectra, zeta potential value, dynamic light scattering, DLS, transmission electron microscopy, TEM, X‐ray diffraction, XRD, Fourier transform infrared spectroscopy, FTIR, surface plasmon resonance, hydrodynamic diameters, colloidal solution, spherical morphology, crystalline structure, crystallite size, biopolymers, Fe₂ O₃      

Memorial consequences of answering SAT II questions.

Many thousands of students take standardized tests every year. In the current research, we asked whether answering standardized test questions affects students' later test performance. Prior research has shown both positive and negative effects of multiple-choice testing on later tests, with negative effects arising from students selecting incorrect alternatives on multiple-choice tests and then believing they were correct (Roediger & Marsh, 2005). In the current experiments, undergraduates and high school students answered multiple-choice questions retired from SAT II tests (that are no longer in the testing pool) on biology, chemistry, U.S. history, and world history, and later answered cued-recall questions about these subjects. In 3 experiments, we observed positive testing effects: More final cued-recall questions were answered correctly if the items had appeared on the initial multiple-choice test. We also sometimes observed negative testing effects: intrusions of multiple-choice distractors as answers on the final cued-recall test. Students who scored well on the initial test benefited from taking the test, but lower achieving students showed either less benefit (undergraduates) or costs from the testing (high school students). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Combining Resource‐Based and Evolutionary Theory to Explain the Genesis of Bio‐networks

This paper examines new firms creating innovative networks to support their development in emerging industries. Resource‐based and evolutionary theories are combined to explain the genesis of a new business ecosystem. Two case studies of biopharm ventures developing drugs against cancer showed how participants altered their selection environment as they enhanced their network's capability. Resource building took place at the firm and network level through collaborative business models involving innovative contractors. This approach uncovered previously unnoticed features of networks for drug development: resource asynchronies were found to be a stimulus to innovation in development networks, as in the Penrosean firm.