The effect of time constraint on anticipation, decision making, and option generation in complex and dynamic environments

Researchers interested in performance in complex and dynamic situations have focused on how individuals predict their opponent(s) potential courses of action (i.e., during assessment) and generate potential options about how to respond (i.e., during intervention). When generating predictive options, previous research supports the use of cognitive mechanisms that are consistent with long-term working memory (LTWM) theory (Ericsson and Kintsch in Phychol Rev 102(2):211–245, 1995; Ward et al. in J Cogn Eng Decis Mak 7:231–254, 2013). However, when generating options about how to respond, the extant research supports the use of the take-the-first (TTF) heuristic (Johnson and Raab in Organ Behav Hum Decis Process 91:215–229, 2003). While these models provide possible explanations about how options are generated in situ, often under time pressure, few researchers have tested the claims of these models experimentally by explicitly manipulating time pressure. The current research investigates the effect of time constraint on option-generation behavior during the assessment and intervention phases of decision making by employing a modified version of an established option-generation task in soccer. The results provide additional support for the use of LTWM mechanisms during assessment across both time conditions. During the intervention phase, option-generation behavior appeared consistent with TTF, but only in the non-time-constrained condition. Counter to our expectations, the implementation of time constraint resulted in a shift toward the use of LTWM-type mechanisms during the intervention phase. Modifications to the cognitive-process level descriptions of decision making during intervention are proposed, and implications for training during both phases of decision making are discussed

Self-harm as the first presentation of attention deficit hyperactivity disorder in adolescents.

BACKGROUND: Self-harm (SH) in adolescence has previously been shown to significantly overlap with both attention deficit hyperactivity disorder (ADHD) and emotional dysregulation (ED). Our objective as such was to investigate the relationship between self-harm and ADHD in our population and consider its clinical relevance. METHODS: This case series analysis examined 124 presentations of SH in 13- to 17 year-olds to Accident and Emergency Departments in South West London (97F:27M). Strength and Difficulties Questionnaires (SDQs) were used to screen for ADHD/hyperactivity and ED, and scores were compared with reference data obtained from Meltzer et al. (1999, International Review of Psychiatry (Abingdon, England), 15, 185). RESULTS: Mean SDQ ADHD/hyperactivity scores were significantly higher in our SH sample compared to reference data (p < .0001). Furthermore, significantly greater ED scores were found in our sample compared with the control reference data. CONCLUSION: Our findings contribute to the evidence for an important link between ADHD and clinical presentations of SH and suggest there to be value in screening girls presenting to A&E with self-harm for ADHD. We speculate that ED plays a role in the evolution of SH in dysregulated ADHD. We recommend that clinicians assessing adolescents have self-harmed to be aware of possible ADHD symptoms and screen as appropriate; however, future research examining the temporal association between ADHD, emotional dysregulation and self-harm is required to establish causal direction

On chains in HH-closed topological pospaces

We study chains in an $H$-closed topological partially ordered space. We give sufficient conditions for a maximal chain $L$ in an $H$-closed topological partially ordered space such that $L$ contains a maximal (minimal) element. Also we give sufficient conditions for a linearly ordered topological partially ordered space to be $H$-closed. We prove that any $H$-closed topological semilattice contains a zero. We show that a linearly ordered $H$-closed topological semilattice is an $H$-closed topological pospace and show that in the general case this is not true. We construct an example an $H$-closed topological pospace with a non-$H$-closed maximal chain and give sufficient conditions that a maximal chain of an $H$-closed topological pospace is an $H$-closed topological pospace.Comment: We have rewritten and substantially expanded the manuscrip

Livestock trade network: potential for disease transmission and implications for risk-based surveillance on the island of Mayotte

The island of Mayotte is a department of France, an outermost region of the European Union located in the Indian Ocean between Madagascar and the coast of Eastern Africa. Due to its close connection to the African mainland and neighbouring islands, the island is under constant threat of introduction of infectious diseases of both human and animal origin. Here, using social network analysis and mathematical modelling, we assessed potential implications of livestock movements between communes in Mayotte for risk-based surveillance. Our analyses showed that communes in the central region of Mayotte acted as a hub in the livestock movement network. The majority of livestock movements occurred between communes in the central region and from communes in the central region to those in the outer region. Also, communes in the central region were more likely to be infected earlier than those in the outer region when the spread of an exotic infectious disease was simulated on the livestock movement network. The findings of this study, therefore, suggest that communes in the central region would play a major role in the spread of infectious diseases via livestock movements, which needs to be considered in the design of risk-based surveillance systems in Mayotte

Importance of Madden–Julian oscillation phase to the interannual variability of East African rainfall

Precipitation across East Africa shows marked interannual variability. Seasonal forecast skill for the OND short rains is significantly higher than for the MAM long rains, which also exhibit poorly understood decadal variability. On sub-seasonal time-scales rainfall is influenced strongly by the phase of the Madden–Julian Oscillation (MJO); here we investigate whether this influence extends to interannual and decadal scales. We show that the number of days that the MJO is active and in phases 1–3 has a greater influence than the mean amplitude of the MJO on interannual long rains variability (ρ = 0.59 for the count of phases 1–3, compared to ρ = 0.40 for amplitude). The frequency of these days is linked to a newly identified gradient in Pacific sea-surface temperatures (SSTs), whose influence on long rains variability we show is itself mediated by the MJO. We develop a statistical model estimating East African rainfall from MJO state, and show that the influence of the MJO on seasonal rainfall extends to the short rains, and to a lesser extent also into January and February. Our results show the importance of capturing the SST-MJO phase relationship in models used for predictions of East African rainfall across time-scales, and motivate investigating this further

Ward's Hierarchical Clustering Method: Clustering Criterion and Agglomerative Algorithm

The Ward error sum of squares hierarchical clustering method has been very widely used since its first description by Ward in a 1963 publication. It has also been generalized in various ways. However there are different interpretations in the literature and there are different implementations of the Ward agglomerative algorithm in commonly used software systems, including differing expressions of the agglomerative criterion. Our survey work and case studies will be useful for all those involved in developing software for data analysis using Ward's hierarchical clustering method.Comment: 20 pages, 21 citations, 4 figure

Do logarithmic proximity measures outperform plain ones in graph clustering?

We consider a number of graph kernels and proximity measures including commute time kernel, regularized Laplacian kernel, heat kernel, exponential diffusion kernel (also called "communicability"), etc., and the corresponding distances as applied to clustering nodes in random graphs and several well-known datasets. The model of generating random graphs involves edge probabilities for the pairs of nodes that belong to the same class or different predefined classes of nodes. It turns out that in most cases, logarithmic measures (i.e., measures resulting after taking logarithm of the proximities) perform better while distinguishing underlying classes than the "plain" measures. A comparison in terms of reject curves of inter-class and intra-class distances confirms this conclusion. A similar conclusion can be made for several well-known datasets. A possible origin of this effect is that most kernels have a multiplicative nature, while the nature of distances used in cluster algorithms is an additive one (cf. the triangle inequality). The logarithmic transformation is a tool to transform the first nature to the second one. Moreover, some distances corresponding to the logarithmic measures possess a meaningful cutpoint additivity property. In our experiments, the leader is usually the logarithmic Communicability measure. However, we indicate some more complicated cases in which other measures, typically, Communicability and plain Walk, can be the winners.Comment: 11 pages, 5 tables, 9 figures. Accepted for publication in the Proceedings of 6th International Conference on Network Analysis, May 26-28, 2016, Nizhny Novgorod, Russi

The activity of French Research Ethics Committees and characteristics of biomedical research protocols involving humans: a retrospective cohort study

BACKGROUND: Clinical trials throughout the world must be evaluated by research ethics committees. No one has yet attempted to clearly quantify at the national level the activity of ethics committees and describe the characteristics of the protocols submitted. The objectives of this study were to describe 1) the workload and the activity of Research Ethics Committees in France, and 2) the characteristics of protocols approved on a nation-wide basis. METHODS: Retrospective cohort of 976 protocols approved by a representative sample of 25/48 of French Research Ethics Committees in 1994. Protocols characteristics (design, study size, investigator), number of revisions requested by the ethics committee before approval, time to approval and number of amendments after approval were collected for each protocol by trained research assistant using the committee's files and archives. RESULTS: Thirty-one percent of protocols were approved with no modifications requested in 16 days (95% CI: 14–17). The number of revisions requested by the committee, and amendments submitted by the investigator was on average respectively 39 (95% CI: 25–53) and 37 (95% CI: 27–46), per committee and per year. When revisions were requested, the main reasons were related to information to the patient (28%) and consent modalities (18%). Drugs were the object of research in 68% of the protocols examined. The majority of the research was national (80%) with a predominance of single-centre studies. Workload per protocol has been estimated at twelve and half hours on average for administrative support and at eleven and half hours for expertise. CONCLUSION: The estimated workload justifies specific and independent administrative and financial support for Research Ethics Committees

The political economy of competitiveness and social mobility

Social mobility has become a mainstream political and media issue in recent years in the United Kingdom. This article suggests that part of the reason for this is that it can serve as a mechanism to discuss policy concerns that appear to be about social justice without questioning important aspects of neo-liberal political economy. The article charts the policy rhetoric on social mobility under both New Labour and the current Coalition Government. It is argued first that under New Labour the apparent commitment to social mobility was in fact subsumed beneath the pursuit of neo-liberal competitiveness, albeit imperfectly realised in policy. Second, the article suggests that under the Coalition Government the commitment to raising levels of social mobility has been retained and the recently published Strategy for Social Mobility promises that social mobility is what the Coalition means when it argues that the austerity programme is balanced with ‘fairness’. Third, however, the Strategy makes clear that the Coalition define social mobility in narrower terms than the previous government. It is argued here that in narrowing the definition the connection with the idea of competitiveness, while still clearly desirable for the Coalition, is weakened. Fourth, a brief analysis of the Coalition's main policy announcements provides little evidence to suggest that even the narrow definition set out in the Strategy is being seriously pursued. Fifth, the international comparative evidence suggests that any strategy aimed at genuinely raising the level of social mobility would need to give much more serious consideration to narrowing levels of inequality. Finally, it is concluded that when considered in the light of the arguments above, the Strategy for Social Mobility – and therefore ‘Fairness’ itself – is merely a discursive legitimation of the wider political economy programme of austerity

Contact Manifolds, Contact Instantons, and Twistor Geometry

Recently, Kallen and Zabzine computed the partition function of a twisted supersymmetric Yang-Mills theory on the five-dimensional sphere using localisation techniques. Key to their construction is a five-dimensional generalisation of the instanton equation to which they refer as the contact instanton equation. Subject of this article is the twistor construction of this equation when formulated on K-contact manifolds and the discussion of its integrability properties. We also present certain extensions to higher dimensions and supersymmetric generalisations.Comment: v3: 28 pages, clarifications and references added, version to appear in JHE