A method to determine volatile contaminants in polyethylene terephthalate (PET) packages by HDC-GC-FID and its application to post-consumer materials

A simple and low cost method to determine volatile contaminants in post-consumer recycled PET flakes was developed and validated by Headspace Dynamic Concentration and Gas Chromatography-Flame Ionization Detection (HDC-GC-FID). The analytical parameters evaluated by using surrogates include: correlation coefficient, detection limit, quantification limit, accuracy, intra-assay precision, and inter-assay precision. In order to compare the efficiency of the proposed method to recognized automated techniques, post-consumer PET packaging samples collected in Brazil were used. GC-MS was used to confirm the identity of the substances identified in the PET packaging. Some of the identified contaminants were estimated in the post-consumer material at concentrations higher than 220 ng.g-1. The findings in this work corroborate data available in the scientific literature pointing out the suitability of the proposed analytical method.

Generalized Sznajd model for opinion propagation

In the last decade the Sznajd model has been successfully employed in modeling some properties and scale features of both proportional and majority elections. We propose a version of the Sznajd model with a generalized bounded confidence rule-a rule that limits the convincing capability of agents and that is essential to allow coexistence of opinions in the stationary state. With an appropriate choice of parameters it can be reduced to previous models. We solved this model both in a mean-field approach (for an arbitrary number of opinions) and numerically in a Barabaacutesi-Albert network (for three and four opinions), studying the transient and the possible stationary states. We built the phase portrait for the special cases of three and four opinions, defining the attractors and their basins of attraction. Through this analysis, we were able to understand and explain discrepancies between mean-field and simulation results obtained in previous works for the usual Sznajd model with bounded confidence and three opinions. Both the dynamical system approach and our generalized bounded confidence rule are quite general and we think it can be useful to the understanding of other similar models.

Statistics of opinion domains of the majority-vote model on a square lattice

The existence of juxtaposed regions of distinct cultures in spite of the fact that people's beliefs have a tendency to become more similar to each other's as the individuals interact repeatedly is a puzzling phenomenon in the social sciences. Here we study an extreme version of the frequency-dependent bias model of social influence in which an individual adopts the opinion shared by the majority of the members of its extended neighborhood, which includes the individual itself. This is a variant of the majority-vote model in which the individual retains its opinion in case there is a tie among the neighbors' opinions. We assume that the individuals are fixed in the sites of a square lattice of linear size L and that they interact with their nearest neighbors only. Within a mean-field framework, we derive the equations of motion for the density of individuals adopting a particular opinion in the single-site and pair approximations. Although the single-site approximation predicts a single opinion domain that takes over the entire lattice, the pair approximation yields a qualitatively correct picture with the coexistence of different opinion domains and a strong dependence on the initial conditions. Extensive Monte Carlo simulations indicate the existence of a rich distribution of opinion domains or clusters, the number of which grows with L(2) whereas the size of the largest cluster grows with ln L(2). The analysis of the sizes of the opinion domains shows that they obey a power-law distribution for not too large sizes but that they are exponentially distributed in the limit of very large clusters. In addition, similarly to other well-known social influence model-Axelrod's model-we found that these opinion domains are unstable to the effect of a thermal-like noise.

An opinion dynamics model for the diffusion of innovations

We study the dynamics of the adoption of new products by agents with continuous opinions and discrete actions (CODA). The model is such that the refusal in adopting a new idea or product is increasingly weighted by neighbor agents as evidence against the product. Under these rules, we study the distribution of adoption times and the final proportion of adopters in the population. We compare the cases where initial adopters are clustered to the case where they are randomly scattered around the social network and investigate small world effects on the final proportion of adopters. The model predicts a fat tailed distribution for late adopters which is verified by empirical data. (C) 2009 Elsevier B.V. All rights reserved.

Bayesian updating rules in continuous opinion dynamics models

Here, I investigate the use of Bayesian updating rules applied to modeling how social agents change their minds in the case of continuous opinion models. Given another agent statement about the continuous value of a variable, we will see that interesting dynamics emerge when an agent assigns a likelihood to that value that is a mixture of a Gaussian and a uniform distribution. This represents the idea that the other agent might have no idea about what is being talked about. The effect of updating only the first moments of the distribution will be studied, and we will see that this generates results similar to those of the bounded confidence models. On also updating the second moment, several different opinions always survive in the long run, as agents become more stubborn with time. However, depending on the probability of error and initial uncertainty, those opinions might be clustered around a central value.

Continuous opinions and discrete actions in opinion dynamics problems

A model where agents show discrete behavior regarding their actions, but have continuous opinions that are updated by interacting with other agents is presented. This new updating rule is applied to both the voter and Sznajd models for interaction between neighbors, and its consequences are discussed. The appearance of extremists is naturally observed and it seems to be a characteristic of this model.

Consumer purchase habits and views on food safety: A Brazilian study

This study aimed to evaluate the attitudes towards food safety among consumers in the city of So Paulo, the major consumer market in Brazil. Focus group sessions were conducted with 30 adults responsible for food choices and purchases. Results indicated a preference for supermarkets over street markets, for the variety of foods, convenience and confidence in the safety assurance. On the other hand, the ""naturalness"" of the products in the street markets was the main reason for purchases in those places. Participants showed concerns with respect to food additives, hormones and pesticides - technological rather than ""natural"" hazards. Minimally processed and ready-to-eat foods were considered convenient products meeting the need for time/labor-savings in the kitchen, although suspicion about wholesomeness and safety came up among consumers. Lack of awareness regarding potentially risky behaviors was observed, including handling and storage of foods in the domestic environment. In conclusion, this study suggests that Brazilian regulators should create more effective risk communication combining technical information with actual consumer perceptions of food risks. (C) 2010 Elsevier Ltd. All rights reserved.

Brazilian consumer views on food irradiation

This study investigated the consumer attitude to food irradiation in Sao Paulo, Brazil, through a qualitative research perspective. Three focus groups were conducted with 30 consumers, responsible for food choices and purchases. Both irradiated and nonirradiated food samples were served in the sessions to motivate the discussion and elicit the participants knowledge, opinions, feelings and concerns towards the irradiation process. Reactions were similar among the groups and differences between the irradiated and the nonirradiated samples were hardly perceived. When provided with positive information about irradiation and its benefits to foods and human health, many people still remained suspicious about the safety of the technology. Risk perception seemed to be related to unease and lack of knowledge about nuclear power and its non-defense use. Participants claimed for more transparency in communication about risks and benefits of irradiated foods to the human health, especially with respect to the continued consumption. Industrial relevance: Irradiation is an emerging food processing technology, which has been gaining interest by food technologists, producers and manufacturers all over the world in the last decades. Irradiation is suitable for disinfestation, microorganism load reduction or sterilization, assuring the safety, as well as having benefits in the shelf-life of foodstuffs. Food irradiation is approved in many countries and its use in food processing is endorsed by several reputed authorities, such as FAD and USDA. Despite the approval and recommendation, this technology still remains underutilized not only in Brazil, but also in other countries. The main reason appears to be the consumer concerns and doubts about the use of radiations in food processing. To develop communication strategies in promotion of irradiated foods it is necessary to investigate consumer attitudes, knowledge. opinions, as well as fears, with respect to the use of radiation in food processing. It is well-known that consumer views on technology may vary from a culture to another. So, findings from consumer research in a country may certainly not reflect the consumer views in other countries. In this sense, Brazilian studies focused on consumer views on food irradiation are necessary to gain understanding on how the local market accepts the technology. Brazil is one of the most important food producers in the world and an emerging consumer market with a population of about 184 million people. Food irradiation is regulated in Brazil since 1973, but to date only a few food ingredients are subjected to irradiation. The wide use of irradiation in food processing would favor Brazilian producers in the quality and safety assurance of food products, both for the local market and for exports. (C) 2009 Elsevier Ltd. All rights reserved.

Consumer`s evaluation of the effects of gamma irradiation and natural antioxidants on general acceptance of frozen beef burger

The effect of addition of rosemary and oregano extracts on the sensory quality of irradiated beef burger was investigated. Batches of beef burgers were prepared with 400 ppm of rosemary or oregano extract and a group prepared with 200 ppm of synthetic butyl-hydroxytoluene (BHT)/butyl-hydroxy-anisol (BHA) was used as a control. Half of each formulation was irradiated at the maximum dose allowed for frozen meat (7 kGy). Samples were kept under frozen conditions (-20 degrees C) during the whole storage period, including during irradiation. Two analyses were performed after 20 and 90 days to verify the influence of the addition of the different types of antioxidants and the effect of irradiation and storage time on the acceptance of the product. Thirty-three and thirty-four untrained panelists were invited to participate in the first and second test, respectively. A structured hedonic scale ranging from 1 to 9 points was used in both analyses. BHT/BHA formulation obtained the highest score (6.73) and regarding the natural antioxidants, oregano received better acceptance (6.36). Irradiated samples formulated with oregano received a lower score, 6.03 in the first test and 5.06 in the second one, compared to the non-irradiated sample (6.36 and 5.79). In the second test (90 days), the sample formulated with BHT/BHA and which was irradiated received a higher score (6.59) when compared to the non-irradiated one (5.85). In both tests, the irradiated samples formulated with rosemary extract obtained a better score compared to the non-irradiated one, the scores being 5.00-3.82 and 5.00-3.76 in the first and second test, respectively. Our results allowed us to conclude that the natural antioxidants, rosemary and oregano extracts, present a good alternative for replacing synthetic additives in food industries, and that the irradiation process, in some cases, may help to enhance the sensory quality of food. (C) 2008 Elsevier Ltd. All rights reserved.

Communism and Public Opinion in Queensland, 1939-1951 : An Explanation of Queensland's Vote in the 1951 Anti-Communist Referendum

The starting point of this thesis was a desire to explain the rapid demise in the popularity which the Communist Party enjoyed in Queensland during the second world war. Wartime Queensland gave the Australian Communist Party its highest state vote and six years later Queensland again gave the Communist Party its highest state vote - this time however, to ban the Party. From this I was led into exploring the changing policies, beliefs and strategies of the Party, as well as the many sub-groups on its periphery, and the shifts in public response to these. In 1939 Townsville elected Australia's first Communist alderman. Five years later, Bowen elected not only Australia's first but also the British Empire's first, Communist state government member. Of the five electorates the Australian Communist Party contested in the 1944 Queensland State elections, in none did the Party's candidate receive less than twenty per-cent of the formal vote. Not only was the Party seemingly enjoying considerable popular support but this was occurring in a State which, but for the Depression years (May 1929 - June 1932) had elected a Labor State Government at every state election since 1915. In the September 1951 Constitution Alteration Referendum, 'Powers To Deal With Communists and Communism', Queensland regist¬ered the nation's highest "Yes" majority - 55.76% of the valid vote. Only two other states registered a majority in favour of the referendum's proposals, Western Australia and Tasmania. As this research was undertaken it became evident that while various trends exhibited at the time, anti-Communism, the work of the Industrial Groups, Labor opportunism, local area feelings, ideological shifts of the Party, tactics of Communist-led unions, etc., were present throughout the entire period, they were best seen when divided into three chronological phases of the Party's history and popularity. The first period covers the consolidation of the Party's post-Depression popularity during the war years as it benefited from the Soviet Union's colossal contribution to the Allied war efforts, and this support continued for some six months or so after the war. Throughout the period Communist strength within the trade union movement greatly increased as did total Party membership. The second period was marked by a rapid series of events starting in March 1946, with Winston Churchill's "Official Opening" of the Cold War by his sweeping attack on Communism and Russia, at Fulton. Several days later the first of a series of long and bitter strikes in Communist-led unions occurred, as the Party mobil¬ized for what it believed would be a series of attacks on the working class from a ruling class, defending a capitalist system on the verge of an economic collapse. It was a period when the Party believed this ruling class was using Labor reformism as a last desperate 'carrot' to get workers to accept their lot within a capitalist economic framework. Out of the Meat Strike emerged the Industrial Groups, who waged not only a determined war against Communist trade union leadership but also encouraged the A.W.U.-influenced State Labor apparatus to even greater anti-Communist antagonisms. The Communist Party's increasing militancy and Labor's resistance to it, ended finally in the collapse of the Chifley Labor government. Characteristically the third period opens with the Communist Party making an another about-face, desperately trying to form an alliance with the Labor Party and curbing its former adventurist industrial policy, as it prepared for Menzies' direct assault. The Communist Party's activities were greatly reduced, a function of both a declining member-ship and, furthermore, a membership reluctant to confront an increasingly hostile society. In examining the changing policies, beliefs and strategies of the Party and the shifts in public response to these, I have tried to distinguish between general trends occurring within Australia and the national party, and trends peculiar to Queensland and the Queensland branch of the Party, The Communist Party suffered a decline in support and membership right across Australia throughout this period as a result of the national policies of the Party, and the changing nature of world politics. There were particular features of this decline that were peculiar to Queensland. I have, however, singled out three features of particular importance throughout the period for a short but more specifically detailed analysis, than would be possible in a purely chronological study: i.e. the Party's structure, the Party's ideological subservience to Moscow, and the general effect upon it of the Cold War.

Combining GIS and Expert Opinion to Model Landscapes for a Smallholder Forest Extension Program in Leyte, the Philippines

A Geographic Information System (GIS) was used to model datasets of Leyte Island, the Philippines, to identify land which was suitable for a forest extension program on the island. The datasets were modelled to provide maps of the distance of land from cities and towns, land which was a suitable elevation and slope for smallholder forestry and land of various soil types. An expert group was used to assign numeric site suitabilities to the soil types and maps of site suitability were used to assist the selection of municipalities for the provision of extension assistance to smallholders. Modelling of the datasets was facilitated by recent developments of the ArcGIS® suite of computer programs and derivation of elevation and slope was assisted by the availability of digital elevation models (DEM) produced by the Shuttle Radar Topography (SRTM) mission. The usefulness of GIS software as a decision support tool for small-scale forestry extension programs is discussed.

Women's satisfaction with general practice consultations

Objective: To determine women's satisfaction with general practice services. Design: Cross-sectional postal questionnaire conducted during April to September 1996 (part of the baseline survey of the Australian Longitudinal Study on Women's Health). Participants: Women aged 18-22 (n=14739), 45-49 (n=14013) and 70-74 (n=12941) years, randomly selected from the Medicare database, with oversampling of women from rural and remote areas. Main outcome measures: Frequency of use of general practice services; satisfaction with the most recent visit to a general practitioner (CP), prevalence of selected symptoms; preference for a female doctor. Results: The most recent visit to a GP was rated overall as good, very good or excellent by more than 80% of women, with increasing levels of satisfaction with increasing age of the women. However, satisfaction was lower for waiting room time and cost of the visit. A third of the young and middle-aged women living in rural and remote areas were dissatisfied with the cost of the visit. Young women were more likely to prefer a female doctor, and many were dissatisfied with their GP's skills at explaining their problem and giving them a chance to give an opinion and ask questions. The most prevalent symptoms for all women included headaches and tiredness, and many were not satisfied with the health services available to help them deal with these symptoms. Conclusions: Australian women have high levels of satisfaction with GP consultations. However, more effective strategies may be needed to improve communication with younger women, and there is an unmet need for services to help all women deal with some common symptoms. Dissatisfaction with cost of services and women's preference for female doctors have implications for future health policy.

Exploratory Approach to the use of Techniques of Regression Analysis and Pooled Analysis in Studies of Consumer Behavior

This paper is part of a large study to assess the adequacy of the use of multivariate statistical techniques in theses and dissertations of some higher education institutions in the area of marketing with theme of consumer behavior from 1997 to 2006. The regression and conjoint analysis are focused on in this paper, two techniques with great potential of use in marketing studies. The objective of this study was to analyze whether the employement of these techniques suits the needs of the research problem presented in as well as to evaluate the level of success in meeting their premisses. Overall, the results suggest the need for more involvement of researchers in the verification of all the theoretical precepts of application of the techniques classified in the category of investigation of dependence among variables.

What is an effective health consumer? A convergent interviewing approach

This study is part of a larger project on the measurement of effective health consumers in the context of musculoskeletal illness. This complex issue involves the progressive nature of the disease, invisibility of the illness and attendant impairments, complexity of decision-making and negotiation, and urgent need to translate emergent evidence about treatment and management to patients and health professionals. We conducted indepth interviews with patients, family members, general practitioners, specialist clinicians, and health consumer advocates (N = 84) about effective consumers in this context, using a process of convergent interviewing, with convergence conducted within and across groups and countries. The initial set of themes included information seeking and adaptation, decision-making, roles of patients, GPs, and specialists and communication between them, importance of pain and impact of depression, impact of the social environment (including the invisibility of the disease and the need for a normal life), and coping strategies.