Kinetic analysis of the interaction of the copper chaperone Atox1 with the metal binding sites of the Menkes protein

Excess copper is effluxed from mammalian cells by the Menkes or Wilson P-type ATPases (MNK and WND, respectively). MNK and WND have six metal binding sites (MBSs) containing a CXXC motif within their N-terminal cytoplasmic region. Evidence suggests that copper is delivered to the ATPases by Atox1, one of three cytoplasmic copper chaperones. Attempts to monitor a direct Atox1-MNK interaction and to determine kinetic parameters have not been successful. Here we investigated interactions of Atox1 with wild-type and mutated pairs of the MBSs of MNK using two different methods: yeast two-hybrid analysis and real-time surface plasmon resonance (SPR). A copper-dependent interaction of Atox1 with the MBSs of MNK was observed by both approaches. Cys to Ser mutations of conserved CXXC motifs affected the binding of Atox1 underlining the essentiality of Cys residues for the copper-induced interaction. Although the yeast two-hybrid assay failed to show an interaction of Atox1 with MBS5/6, SPR analysis clearly demonstrated a copper-dependent binding with all six MBSs highlighting the power and sensitivity of SPR as compared with other, more indirect methods like the yeast two-hybrid system. Binding constants for copper-dependent chaperone-MBS interactions were determined to be 10–5-10–6 M for all the MBSs representing relatively low affinity binding events. The interaction of Atox1 with pairs of the MBSs was non-cooperative. Therefore, a functional difference of the MBSs in the MNK N terminus cannot be attributed to cooperativity effects or varying affinities of the copper chaperone Atox1 with the MBSs.

Inter-firm complementarities in R&D : a re-examination of the relative performance of joint ventures

We compare duopoly outcomes between two alternative modes of research and development (R&D), viz. independent R&D and non-cooperative research joint ventures (RJVs), when there are complementarities between firm-specific R&D resources. When complementarity is high, RJVs lead to higher technological improvement and the reverse holds for low complementarity. In the intermediate range, the comparison depends on the relative imperfection in spillovers afflicting independent R&D. In sharp contrast to results on cooperative RJVs, non-cooperative RJVs lead to higher technological improvement when spillovers affecting independent R&D are low; the reverse holds for high spillovers. When RJVs yield higher technological improvement, they also yield higher industry profit and social welfare.

Use of electronic games by young children and fundamental movement skills?

This study investigated associations between pre-school children's time spent playing electronic games and their fundamental movement skills. In 2009, 53 children had physical activity (Actigraph accelerometer counts per minute), parent proxy-report of child's time in interactive and non-interactive electronic games (min./week), and movement skill (Test of Gross Motor Development–2) assessed. Hierarchical linear regression, adjusting for age (range = 3–6 years), sex (Step 1), and physical activity (cpm; M = 687, SD = 175.42; Step 2), examined the relationship between time in (a) non-interactive and (b) interactive electronic games and locomotor and object control skill. More than half (59%, n = 31) of the children were female. Adjusted time in interactive game use was associated with object control but not locomotor skill. Adjusted time in non-interactive game use had no association with object control or locomotor skill. Greater time spent playing interactive electronic games is associated with higher object control skill proficiency in these young children. Longitudinal and experimental research is required to determine if playing these games improves object control skills or if children with greater object control skill proficiency prefer and play these games.

The effect of mathematical games on on-task behaviours in the primary classroom

A challenge for primary classroom teachers is to maintain students’ engagement with learning tasks while catering for their diverse needs, capabilities and interests. Multiple pedagogical approaches are employed to promote on-task behaviours in the mathematics classroom. There is a general assumption by educators that games ignite children’s on-task behaviours, but there is little systemically researched empirical data to support this claim. This paper compares students’ on-task behaviours during non-digital game-playing lessons compared with non-game-playing lessons. Six randomly selected grade 5 and 6 students (9–12 year olds) were observed during ten mathematics lessons. A total of 2,100 observations were recorded via an observational schedule and analysed by comparing the percentage of exhibited behaviours. The study found the children spent 93 % of the class-time exhibiting on-task engagement during the game-playing lessons compared with 72 % during the non-game-playing lessons. The game-playing lessons also promoted greater incidents of student talk related to the mathematical task (34 %) compared with the non-game playing lessons (11 %). These results support the argument that games serve to increase students’ time-on-task in mathematics lessons. Therefore, it is contended that use of games explicitly addressing the mathematical content being taught in a classroom is one way to increase engagement and, in turn, potential for learning.

An improved consensus-based group decision making model with heterogeneous information

In group decision making (GDM) problems, it is natural for decision makers (DMs) to provide different preferences and evaluations owing to varying domain knowledge and cultural values. When the number of DMs is large, a higher degree of heterogeneity is expected, and it is difficult to translate heterogeneous information into one unified preference without loss of context. In this aspect, the current GDM models face two main challenges, i.e., handling the complexity pertaining to the unification of heterogeneous information from a large number of DMs, and providing optimal solutions based on unification methods. This paper presents a new consensus-based GDM model to manage heterogeneous information. In the new GDM model, an aggregation of individual priority (AIP)-based aggregation mechanism, which is able to employ flexible methods for deriving each DM's individual priority and to avoid information loss caused by unifying heterogeneous information, is utilized to aggregate the individual preferences. To reach a consensus more efficiently, different revision schemes are employed to reward/penalize the cooperative/non-cooperative DMs, respectively. The temporary collective opinion used to guide the revision process is derived by aggregating only those non-conflicting opinions at each round of revision. In order to measure the consensus in a robust manner, a position-based dissimilarity measure is developed. Compared with the existing GDM models, the proposed GDM model is more effective and flexible in processing heterogeneous information. It can be used to handle different types of information with different degrees of granularity. Six types of information are exemplified in this paper, i.e., ordinal, interval, fuzzy number, linguistic, intuitionistic fuzzy set, and real number. The results indicate that the position-based consensus measure is able to overcome possible distortions of the results in large-scale GDM problems.

Explaining non-renewal behaviour : an empirical investigation of recently lapsed NRL club members

This paper reports on a survey of lapsed members of an Australian professional National Rugby League (NRL) Club. Analysis of the 195 useable responses returned suggest that these lapsed members had originally joined as much for intangible aspects, such as seeking a greater level of involvement with the club, as for the functional aspects such as savings on game entry. Overall, these lapsed members were satisfied with the service they received whilst a member, and claimed it had been performed in line with expectations. The main drivers of satisfaction were also a mix of tangible and intangible factors such as feeling valued by the club and receiving discounts on entry costs. The members gave a number of reasons for not rejoining in 2002, but primarily cited an inability to attend games. Despite joining for intangible reasons, it seems that if these members could not get to games, they perceived that membership was not worth maintaining. That said, a large number of members indicated that as their circumstances change they will rejoin the club, supporting the theory that non-renewal is not driven by service failure, but rather the perception that attendance is still the core product (entertainment). The overall level of satisfaction had a weak but positive relationship with the likelihood of members rejoining in the future.

Stability of television viewing and electronic game/computer use in a prospective cohort study of Australian children: relationship with body mass index

Background
While much cross-sectional data is available, there have been few longitudinal investigations of patterns of electronic media use in children. Further, the possibility of a bi-directional relationship between electronic media use and body mass index in children has not been considered. This study aimed to describe longitudinal patterns of television viewing and electronic game/computer use, and investigate relationships with body mass index (BMI).
Methods
This prospective cohort study was conducted in elementary schools in Victoria, Australia. 1278 children aged 5–10 years at baseline and 8–13 years at follow-up had their BMI calculated, from measured height and weight, and transformed to z-scores based on US 2000 growth data. Weight status (non-overweight, overweight and obese) was based on international BMI cut-off points. Weekly television viewing and electronic game/computer use were reported by parents, these were summed to generate total weekly screen time. Children were classified as meeting electronic media use guidelines if their total screen time was ≤14 hrs/wk.
Results
Electronic media use increased over the course of the study; 40% met guidelines at baseline but only 18% three years later. Television viewing and electronic game/computer use tracked moderately and total screen time was positively associated with adiposity cross-sectionally. While weaker relationships with adiposity were observed longitudinally, baseline z-BMI and weight status were positively associated with follow-up screen time and baseline screen time was positively associated with z-BMI and weight status at follow-up. Children who did not meet guidelines at baseline had significantly higher z-BMI and were more likely to be classified as overweight/obese at follow-up.

Conclusion
Electronic media use in Australian elementary school children is high, increases with age and tracks over time. There appears to be a bi-directional association suggesting that interventions targeting reductions in either screen time or adiposity may have a positive effect on both screen time and adiposity.

Learn to design vs design to learn: enhancing educational opportunities using game technoloy

Recognizing as children’s input in game design and development process is critical, we applied cooperative inquiry experiences working with young children as game design partners. The computer-based games specifically were designed and developed for the acquisition of survival literacy by 12-14 year old intellectually disabled children. During the design and development game process, children learnt game design techniques without their acknowledgement. Importantly, the development process will be undertaken by the students with the minimum guidance of team members. The experiences, challenges and lesson learned through game design process are discussed.

Aggressive tax planning : differentiating those playing the game from those who don't

The study reported in this paper examined a group of Australian taxpayers who have expressed a preference for a creative and aggressive tax agent. The study attempted to understand how high-risk taxpayers and high-risk practitioners form their partnerships by examining aggressive taxpayers' attitudes and perceptions of the Australian tax system. Data were taken from 2040 Australian taxpayers who had responded to a national survey on tax issues. Results from a series of independent sample t-tests revealed that there are a number of important differences between 'aggressive' and 'non-aggressive' taxpayers. Finally, a logistic regression analysis was used to determine which variables most effectively differentiated aggressive taxpayers from non-aggressive taxpayers. The findings are discussed in a regulatory context and possible solutions for how tax authorities might deal with this high-risk group of taxpayer are suggested.

Game of Tropes: the Orientalist tradition in the Works of G.R.R. Martin

George R.R. Martin's A Song of Ice and Fire novels (and their television adaption, Game of Thrones) have become arguably the most well known fantasy epic of the last decade. However, the world of A Song of Ice and Fire conforms to many of the same Orientalist tropes that have dominated Western literature since the popularisation of the 'Arabian fantasy' in the 18th and 19th centuries and its subsequent perpetuation in film and television. Derivative imaginings of the real world Middle East are commonly reflected in non-Earthly fantasy worlds and Martin's work incorporates this standard vision of the Eastern Other. Owing to its popularity, the A Song of Ice and Fire series represents a significant reinforcement of Orientalist stereotypes and proves that fantasy locations have significant power to cement these ideas in the popular imagination. Moreover, the negative portyal of the East in these works supports Said's argument that the Orient is an invention of the West, and that our depiction of the Other is a means of framing our own cultural superiority.

The relative importance of spatial proximity, kin selection and potential ‘greenbeard’ signals on provisioning behaviour among helpers in a cooperative bird

© 2015 Springer-Verlag Berlin Heidelberg Many hypotheses have been proposed to account for cooperative behaviour, with those favouring kin selection receiving the greatest support to date. However, the importance of relatedness becomes less clear in complex societies where interactions can involve both kin and non-kin. To help clarify this, we examined the relative effect of indirect versus key direct benefit hypotheses in shaping cooperative decisions. We assessed the relative importance of likely reciprocal aid (as measured by spatial proximity between participants), kin selection (using molecular-based relatedness indices) and putative signals of relatedness (vocal similarity) on helper/helper cooperative provisioning dynamics in bell miners (Manorina melanophrys), a species living in large, complex societies. Using network analysis, we quantified the extent of shared provisioning (helping at the same nests) among individual helpers (excluding breeding pairs) over three seasons and 4290 provisioning visits, and compared these with the location of individuals within a colony and networks built using either genetic molecular relatedness or call similarity indices. Significant levels of clustering were observed in networks; individuals within a cluster were more closely related to each other than other colony members, and cluster membership was stable across years. The probability of a miner helping at another’s nest was not simply a product of spatial proximity and thus the potential for reciprocal aid. Networks constructed using helping data were significantly correlated to those built using molecular data in 5 of 10 comparisons, compared to 8 of 10 comparisons for networks constructed using call similarity. This suggests an important role of kinship in shaping helping dynamics in a complex cooperative society, apparently determined via an acoustic ‘greenbeard’ signal in this system.