Information versus Communication in Course Management System participation

Web resources in Latin American higher education institutions have been reported to show a much stronger emphasis on Information than on Communication. A Course Management System (CMS), according to Social Constructivism framework, is an opportunity for fostering learning through interaction in a virtual environment for learning; hence, stimulating the use of a CMS for communication purposes seems quite appropriate. A quantitative analysis of 63.06% of the virtual classrooms was conducted, using the users log database to describe five variables: Participation, Informational Interaction Level, Communicational Interaction Level, and the use of Informational Resources and Communicational Resources in the CMS. An assessment of the first 2 years of implementation of Moodle in a campus confirmed prominence levels of interaction and resources that favor Information over Communication purposes in the use of the CMS. It is not conclusive whether this necessarily implies more or better learning; a profound qualitative study would be needed to answer these questions. Teachers and students show different behaviors in the face of this new ICT campus resource, while faculty members appear to have behaved in an erratic manner, students show steady levels of CMS usage.     

Antioxidant behaviour of products resulting from beef sarcoplasmic proteins‐malondialdehyde reaction

The antioxidant properties of the soluble fraction of a Maillard reaction product (MRP) model generated from sarcoplasmic protein/malondialdehyde (MDA) were evaluated. The dry extract colour values showed that it has a pale brown colour appearance, and the carbonyl content of isolated protein increased from 2474 nmol/mg protein to 3904 nmol/mg protein, before and after reaction with MDA, respectively. Reducing power (82.34%) and 1,1‐diphenyl‐2‐picryl hydrazyl radical scavenging (35.20%) were very good, while superoxide anion scavenging showed poor inhibition (324 equivalent SOD units/g). Antioxidant activity in the fused lard system was stronger than in the emulsion system, on all parameters tested, exerting 89% reduction on hydroperoxides, 78% on thiobarbituric acid‐reactive substances (TBARS) and 69% on conjugated dienes (CD) at 80 °C. In the linoleic acid/water emulsion system, the antioxidant activity, measured as peroxide formation inhibition at 37 °C, at the higher concentration assayed was 81%, whereas on CD and on TBARS, it exerted a moderate inhibition (45% and 58%). At 80 °C, the antioxidant activity, for the same concentration, was less effective (37% on CD; 75% on peroxide values, and 40% on TBARS). In conclusion, the sarcoplasmic protein/MDA reaction products showed an excellent antioxidant activity in fused lard and a good performance in the linoleic/water emulsion system.     

Antioxidant properties of polyphenol‐containing extract from soybean fermented with Saccharomyces cerevisiae

The antioxidant properties and total phenolic compounds of soybean extract fermented with Saccharomyces cerevisiae during 24 h were evaluated. Total polyphenolic compounds extracted in ethanol/water (1:1) solution were 789.54 mg/g dry extract, and flavonoids were 169.47 mg quercetin equivalents/g of dry extract. Reducing power (91.18%) and DPPH scavenging (79.30% at 4‐times diluted) were excellent, and so high as BHA, 92.17% and 73.8% respectively, while superoxide anion scavenging showed poor inhibition (4876 equivalent SOD U/g). Antioxidant activity in linoleic acid/water emulsion system of fermented extract measured as peroxide formation inhibition at 37 °C was the strongest (95.62%), while it exerted a moderate inhibition for conjugated dienes and thiobarbituric acid reactive substances (64.77% and 54.33%). At 80 °C the antioxidant activity assayed at a higher concentration was less effective (29.35% on CD; 74.58% on PV and 35.04% on TBARS).     

Model checking multi-level and recursive nets

With the increasing complexity of the problems and systems arising nowadays, the use of multi-level models is becoming more frequent in practice. However, there are still few reports in the literature concerning methods for analyzing such models without flattening the multi-level structure. For instance, several variants of multi-level Petri nets have been applied for modeling interaction protocols and mobility in multi-agent systems and coordination of cross-organizational workflows. But there are few automated tools for analyzing the behavior of these nets. In this paper we explain how to detect faults in models based on a representative class of multi-level nets: the nested Petri nets. We translate a nested net into a verifiable model that preserves its modular structure, a PROMELA program. This allows the use of SPIN model checker to verify properties related to termination, boundedness and reachability.     

Impoundments affect fish reproduction regardless of reproductive strategy

Major changes to local river habitats, after impoundment, are expected to restrict the reproductive activity of fishes with migratory strategies, although the changes are not expected to have relevant effects on fishes with other strategies. The reproductive activity of fishes with different reproductive strategies was evaluated along a longitudinal gradient before, and after, the formation of a reservoir on the Tocantins River (Tocantins State, Brazil). Samples were collected at six sites distributed along 80‐km stretch of the reservoir (R1 to R6 in the upstream–downstream direction) before and after the impoundment. The highest mean values of the reproductive activity index (RAI), considering all species in the river phase, were recorded for the intermediate segments (R4). The reproductive activity was classified as intense at the two sites located further upstream (R2 and R1). The highest mean RAI value after impoundment was observed for the site further upstream (R1). The reproductive activity was classified as intense, however, at every site, except for R6. Regardless of the reproductive strategy, mean RAI values were higher in this phase at site R1, particularly for long‐distance migratory species (LDM). The most lacustrine area (R6) was only relevant for the group of species with parental care. For non‐long‐distance migratory species, without parental care, the reproductive activity was intense at every site, except for R6. Overall, after the impoundment, the fish species tended to seek more lotic environments to spawn, including the riverine zone of the reservoir and side tributaries, regardless of the reproductive strategy. The results of this study provide evidence that impoundments affect the reproduction of the fish, independent of the reproductive strategy, although the intensity of the effect is different for each group.     

Water governance, resilience and global environmental change - a reassessment of integrated water resources management (IWRM).

Integrated Water Resource Management (IWRM) is gaining increased acceptance among water policy makers and researchers as a way to create more effective governance institutions, leading towards integrated water development solutions for poverty alleviation, while addressing social, economic and environmental aspects of water challenges. However, global environmental change poses fundamental challenges to water policy makers as it implies vast scientific, and hence, policy uncertainty; its implications for international water governance initiatives remain unspecified, effectively hindering dialogue on how current IWRM initiatives should be modified. This paper addresses the lag between our growing understanding of resilient interconnected freshwater resources (and their governance) and the reforms being promoted by policy makers. In particular, there is a need to rethink some of IWRM's key components to better tackle the challenges posed by the complex behaviour of interconnected social-ecological systems and global environmental change.     

On parameter estimation for excitation control of synchronous generators

This paper deals with the problem of identification of the network parameters and the desired equilibrium in applications of excitation control for synchronous generators. Our main contribution is the construction of a new non‐linear identifier that provides asymptotically consistent estimates (with guaranteed transient bounds) of the line impedance and the equilibrium for the classical three‐dimensional flux‐decay model of a single generator connected to an infinite bus. This model is non‐linear, and non‐linearly parameterized, and the equilibria depend also non‐linearly on the unknown parameters. The proposed estimator can be used, adopting a certainty equivalent approach, to make adaptive any power system stabilizer that relies on the knowledge of these parameters. The behaviour of the scheme is illustrated in two simulated case studies with the interconnection and damping assignment passivity‐based controller recently proposed by the authors. Copyright © 2004 John Wiley & Sons, Ltd.     

Influence of heating time and oxygen availability on lipid oxidation in meat emulsions

The aim of the present study was to investigate the effect of heating time and oxygen availability on lipid oxidation during chill storage, using different step indicators, in a meat emulsion model. Lipid oxidation was measured by conjugated dienes, hydroperoxides and 2‐thiobarbituric acid reactive substances formation on raw and cooked meat emulsion at 80 °C in different oxygen availability bags, at 0 °C during 35 d. The results obtained showed that heat treatment and oxygen availability affected conjugated dienes, hydroperoxides and 2‐thiobarbituric acid reactive substances formation during chill storage. Besides cooked meat emulsion did not have a similar behaviour to that of raw samples. Thus, is very important to follow primary and secondary products of oxidative deterioration to understand the effect of heat treatment and oxygen availability overall lipid oxidation process in meat emulsion.     

An energy-shaping approach to the design of excitation control of synchronous generators

In this paper we discuss the estimation of the domain of attraction of equilibria in power systems and propose a new passivity-based controller design methodology for excitation control of synchronous generators. The methodology goes beyond the widely popular damping injection (L_gV) schemes, to actually shape the total energy function via modification of the energy transfer between the mechanical and electrical components of the system. Applying the procedure it is shown that a, properly tuned, linear state feedback enlarges both the estimates and the actual domain of attraction, thus increasing critical clearing time for faults. This is illustrated in two case studies, including a benchmark comparison with the classical control scheme.     

Ozone Therapy in Patients with Retinitis Pigmentosa

The aim of this study is to determine the efficacy of ozone therapy in patients with Retinitis Pigmentosa (RP). A controlled, randomized, double blind clinical trial involving 68 patients was performed. Patients were divided into 2 groups: ozone, patients treated with ozone by rectal administration (dose=10?mg), during 15 sessions; control, as ozone group, but using oxygen. The main outcome variable was the visual field area (VFA). Results demonstrated a significant improvement (SI) in 88.2% of patients treated with ozone in comparison with 23.5% achieved in the control group. In the ozone group, VFA tend to stabilize beyond a mean time of 6.83 months with a loose in SI afterward. A temporal positive effect of ozone therapy. Over the natural course of RP, was found.