One Iowa Report, November/October 2007

This bi-monthly newsletter will keep Iowans informed of the important issues and events that are taking place both here in the Capitol and around the state.

One Iowa Report, September/October 2007

This bi-monthly newsletter will keep Iowans informed of the important issues and events that are taking place both here in the Capitol and around the state.

One, two, (three), infinity: Newspaper and lab beauty-contest experiments

"Beauty-contest" is a game in which participants have to choose, typically, a number in [0,100], the winner being the person whose number is closest to a proportion of the average of all chosen numbers. We describe and analyze Beauty-contest experiments run in newspapers in UK, Spain, and Germany and find stable patterns of behavior across them, despite the uncontrollability of these experiments. These results are then compared with lab experiments involving undergraduates and game theorists as subjects, in what must be one of the largest empirical corroborations of interactive behavior ever tried. We claim that all observed behavior, across a wide variety of treatments and subject pools, can be interpretedas iterative reasoning. Level-1 reasoning, Level-2 reasoning and Level-3 reasoning are commonly observed in all the samples, while the equilibrium choice (Level-Maximum reasoning) is only prominently chosen by newspaper readers and theorists. The results show the empirical power of experiments run with large subject-pools, and open the door for more experimental work performed on the rich platform offered by newspapers and magazines.

Improving generalized regression analysis for the spatial prediction of forest communities

Aim This study used data from temperate forest communities to assess: (1) five different stepwise selection methods with generalized additive models, (2) the effect of weighting absences to ensure a prevalence of 0.5, (3) the effect of limiting absences beyond the environmental envelope defined by presences, (4) four different methods for incorporating spatial autocorrelation, and (5) the effect of integrating an interaction factor defined by a regression tree on the residuals of an initial environmental model. Location State of Vaud, western Switzerland. Methods Generalized additive models (GAMs) were fitted using the grasp package (generalized regression analysis and spatial predictions, http://www.cscf.ch/grasp). Results Model selection based on cross-validation appeared to be the best compromise between model stability and performance (parsimony) among the five methods tested. Weighting absences returned models that perform better than models fitted with the original sample prevalence. This appeared to be mainly due to the impact of very low prevalence values on evaluation statistics. Removing zeroes beyond the range of presences on main environmental gradients changed the set of selected predictors, and potentially their response curve shape. Moreover, removing zeroes slightly improved model performance and stability when compared with the baseline model on the same data set. Incorporating a spatial trend predictor improved model performance and stability significantly. Even better models were obtained when including local spatial autocorrelation. A novel approach to include interactions proved to be an efficient way to account for interactions between all predictors at once. Main conclusions Models and spatial predictions of 18 forest communities were significantly improved by using either: (1) cross-validation as a model selection method, (2) weighted absences, (3) limited absences, (4) predictors accounting for spatial autocorrelation, or (5) a factor variable accounting for interactions between all predictors. The final choice of model strategy should depend on the nature of the available data and the specific study aims. Statistical evaluation is useful in searching for the best modelling practice. However, one should not neglect to consider the shapes and interpretability of response curves, as well as the resulting spatial predictions in the final assessment.

Communication, coordination and efficiency in evolutionary one-population models

We analyze the role of commitment in pre-play communication for ensuringefficient evolutionarily stable outcomes in coordination games. All players are a priori identical as they are drawn from the same population. In games where efficient outcomes can be reached by players coordinating on the same action we find commitment to be necessary to enforce efficiency. In games where efficienct outcomes only result from play of different actions, communication without commitment is most effective although efficiency can no longer be guaranteed. Only when there are many messages then inefficient outcomes are negligible as their basins of attraction become very small.

"As you receive with one hand, so should you give with the other": the mutual-help practices of Cape Verdeans on the Lisbon periphery”

Rural Cape Verdeans employ a number of mutual-help practices to mitigate the uncertainties surrounding activities fundamental to their subsistence. One of these practices is djunta mon (‘to work together’), a loosely planned, non-monetized system of allocating labor at peak intervals during the growing season. By means of djunta mon, neighbors or family members work in each other’s fields until the tasks of every landowning participant are complete. Alongside djunta mon in rural Cape Verde exist a number of other non-remunerated mutual-help practices, such as djuda mutua (‘mutual help’) and laja kaza (‘to add concrete to one’s house’). While less visible than djunta mon, they are nonetheless important in completing tasks essential to rural life in the islands. In this thesis, I will attempt to show how Cape Verdean immigrants in Lisbon have adapted the mutual-help practices of rural Cape Verde to a new, transnational context. The iterations of these practices in Lisbon differ from their rural counterparts in that they involve fewer people, occur on a year-round basis, and are concerned primarily with domestic work. They also help people find employment, access childcare, secure interest-free credit, and construct or repair houses. I will argue that extensive mutual-help ties ensure Cape Verdean migrants in Lisbon a sufficient pool of family and friends upon which they can rely for support and assistance. An additional element I will explore is the perception among Cape Verdean immigrants that these mutual-help practices seem to be occurring with less frequency. While this shift is in part due to the availability of other means of support, I will contend that the changing attitude of Cape Verdeans towards mutual help is also due to their encountering neoliberal notions of ‘self-accountability.’ Thus, Cape Verdeans perceive that their mutual-help practices are in decline, while simultaneously needing the material support that they provide.

Three Continents, one Language: Studying English in a Portuguese Landscape (Brazil, Cape Verde and Portugal)

Unlike other languages, English has spread to all continents and become a truly global language, a process observable in countries, like Brazil, Cape Verde, and Portugal, located in three different continents, and sharing a common official language: Portuguese. This relatively recent development has contributed to the wide exposure to English and the growing influence of the language in their societies, being used with lingua franca communicative purposes, which raises pedagogical issues. Our aim is to map the exposure and use of English as a Lingua Franca in these Portuguese speaking countries through a comparative study of the results from three case studies (Berto 2009, Cavalheiro 2008 and Nunes 2010). By taking into consideration the findings from questionnaires answered by students and teachers of English, it compares and contrasts the respondents’ opinions on the profile of English teachers — native vs. non-native —, the varieties of English to be taught, and the language teaching resources available. In addition, it explores the learners’ interests, motives and purposes in relation to English and the potential communicative interactions between all speakers, so as to better understand ELF in English language education, and how these factors affect or should affect pedagogical practices in a Portuguese environment.

More than one inseminated female in colonies of the independent-founding wasp Mischocyttarus cassununga von Ihering (Hymenoptera, Vespidae)

In the primitively eusocial wasps, especially Polistini and Mischocyttarini tribes, the physiological condition of each individual is strongly associated with its dominance status in the colonial hierarchy. As a rule, in independent-founding wasps, female wasps are all morphologically alike, and their role is apparently quite flexible even as adults. However, some studies have shown that differences in body size can exist between reproductive and non-reproductive females. Thus, the present study aimed at detecting differences between reproductive (inseminated) and non-reproductive (uninseminated) individuals based on morphological and physiological parameters. We tape-recorded the daily behavioural repertory of six colonies of Mischocyttarus cassununga for determining the hierarchical dominance in the field, and then collected these colonies (in different cycle stages) for measuring 13 set characters, and assessing the physiological condition of each individual by inspecting their fat bodies and ovaries. Our results revealed that inseminated and uninseminated females are not significantly different in relation to body size, in spite of first group shows higher average than second in almost all measured parts. The physiological evaluation of each individual demonstrated more than one inseminated female per colony during all stages of the colony cycle, suggesting a strategic condition of this species against difficulties (predation and parasitism of the colony) in nature.

Multiple sclerosis-related trigeminal neuralgia: a prospective series of 43 patients treated with gamma knife surgery with more than one year of follow-up.

BACKGROUND: Trigeminal neuralgia (TN) related to multiple sclerosis (MS) is more difficult to manage pharmacologically and surgically. OBJECTIVE: This article aims to evaluate the safety and efficacy of Gamma Knife surgery (GKS) in this special group of patients. METHODS: Between July 1992 and November 2010, 43 cases with more than 1 year of follow-up were operated with GKS for TN related to MS and prospectively evaluated in the Timone University Hospital, Marseille, France. Radiosurgery using the Gamma Knife (model B or C or Perfexion) was performed. A single 4-mm isocenter was positioned at a median distance of 8 mm (range 5.7-14.7) anterior to the emergence of the nerve. A median maximum dose of 85 Gy (range 75-90) was delivered. RESULTS: The median follow-up period was 53.8 months (12-157.1). Thirty-nine patients (90.7%) were initially pain free. Their actuarial probability of remaining pain free without medication at 6 months, 1, 3, 5 and 10 years was 87.2, 71.8, 43.1, 38.3 and 20.5%, respectively, and remained stable till 12 years. The hypoesthesia actuarial rate at 6 months, 1 and 2 years was 11.5, 11.5 and 16%, and remained stable till 12 years. CONCLUSIONS: GKS proved safe and effective in this special group of patients.

Role of the NALP3 Inflammasome in the Development of Two-Kidney, One Clip Hypertension in Mice

Objective: The NALP3 inflammasome functions as a sensor of danger signals and triggers processing and release of IL-1b. Mutations of NALP3 are responsible for the cryopyrin associated periodic syndromes, a group of autoinflammatory disorders that respond to IL1 inhibition. Genetic studies have also linked NALP3 to hypertension in man, but the mechanism is not understood. The aim of this study is to investigate the role of NAPL3 inflammasome in the development of hypertension in an animal model. Design and Method: Six-week old male WT and NALP3 KO mice were used for generating a two-kidney, one clip (2K1C) renovascular hypertension. A U-shaped stainless steel clip (O^ ¼0.12mm) was placed on left renal artery under anaesthesia. The same surgery without clipping was performed in sham mice. At week 6 and 12 after the clipping, intra-arterial blood pressure (BP) was measured in conscious mice. Blood was collected for plasma renin analysis. Heart and kidney were excised and stored for molecular and morphological examinations. n¼5-6 mice per group. Data are mean_SEM. Results: Mean BP was significantly increased at week 6 and 12 in WT-2K1C mice compared to WT-sham group (MBPweek6: 138_2 vs.124_3 mmHg, p<0.01 and MBPweek12: 141_5 vs.122_3 mmHg, p<0.01) followed with an significant increase in heart weight (HW) and a decrease in clipped kidney weight indices in WT-2K1C mice compared to the WT-sham (HW/ BWweek6: 4.65_0.04 vs. 3.99_0.12 mg/g, p<0.001 and HW/BWweek12: 4.94_0.15 vs. 4.22_0.12 mg/g, p<0.001). Interestingly, NALP3 KO-2K1C mice did not develop hypertension. The MBP of KO-2K1C mice was comparable to the KO-sham (MBPweek6: 122_3 vs. 119_3 mmHg, p>0.05 and MBPweek6: 128_5 vs.122_4 mmHg, p>0.05). There was also no significant change in heart and kidney weight indices between KO- 2K1C and KO-sham mice. Conclusion: The preliminary results suggest that absence of NALP3 protects mice from the development of renin-dependent hypertension. Further molecular and morphological examinations are ongoing for the confirmation and mechanism explanation.

Biological cycle of Tenuipalpus heveae Baker (Acari, Tenuipalpidae) on leaflets of three rubber tree clones

Life cycle of Tenuipalpus heveae Baker (Acari, Tenuipalpidae) on leaflets from three rubber tree clones. The biological cycle of Tenuipalpus heveae Baker, 1945 (Tenuipalpidae), a potential rubber tree pest mite, was studied by the observation of individuals reared on leaflets of the clones GT 1, PB 235 and RRIM 600, in controlled environmental conditions. Three daily observations were done of 60 eggs on leaflets from each clone in order to verify the development of immature stages and the female oviposition. The fertility life table was constructed based in the collected data. Mites reared on PB 235 had faster rate of development, requiring less time in days, to double its population in number (TD), and had the highest values for egg production, female longevity, net reproductive rate (Ro), intrinsic rate of natural increase (r m) and finite rate of increase (λ). Lower reproductive values and the longest time necessary to reach adult stage were recorded for the mites on GT 1. In all studied clones, the deutonymphal phase had the highest viability, while the larval phase had the lowest, highlighted by the survivorship curve that indicated high mortality during this life stage. The clone PB 235 allowed the most suitable conditions for the development of T. heveae, followed by RRIM 600, while GT 1 was the less suitable substratum to rear this mite species.

A one-shot Prisoners’ Dilemma with procedural utility

This article introduces a model of rationality that combines procedural utility over actions with consequential utility over payoffs. It applies the model to the Prisoners Dilemma and shows that empirically observed cooperative behaviors can be rationally explained by a procedural utility for cooperation. The model characterizes the situations in which cooperation emerges as a Nash equilibrium. When rational individuals are not solely concerned by the consequences of their behavior but also care for the process by which these consequences are obtained, there is no one single rational solution to a Prisoners Dilemma. Rational behavior depends on the payoffs at stake and on the procedural utility of individuals. In this manner, this model of procedural utility reflects how ethical considerations, social norms or emotions can transform a game of consequences.