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The proportion, number of bouts, and mean bout duration of different vigilance states (Wake, NREM, REM) are useful indices of dynamics in experimental sleep research. These metrics are estimated by first scoring state, sometimes using an algorithm, based on electrophysiological measurements such as the electroencephalogram (EEG) and electromyogram (EMG), and computing their values from the score sequence. Isolated errors in the scores can lead to large discrepancies in the estimated sleep metrics. But most algorithms score sleep by classifying the state from EEG/EMG features independently in each time epoch without considering the dynamics across epochs, which could provide contextual information. The objective here is to improve estimation of sleep metrics by fitting a probabilistic dynamical model to mouse EEG/EMG data and then predicting the metrics from the model parameters. Hidden Markov models (HMMs) with multivariate Gaussian observations and Markov state transitions were fitted to unlabeled 24-h EEG/EMG feature time series from 20 mice to model transitions between the latent vigilance states; a similar model with unbiased transition probabilities served as a reference. Sleep metrics predicted from the HMM parameters did not deviate significantly from manual estimates except for rapid eye movement sleep (REM) ($p<0.01$; Wilcoxon signed-rank test). Changes in value from Light to Dark conditions correlated well with manually estimated differences (Spearman’s rho 0.43–0.84) except for REM. HMMs also scored vigilance state with over 90% accuracy. HMMs of EEG/EMG features can therefore characterize sleep dynamics from EEG/EMG measurements, a prerequisite for characterizing the effects of perturbation in sleep monitoring and control applications.

This paper presents a new SIRI propagation model based on SIR model. Behavioral motivation value and neighbor infection number influence value were added to the model to study the effects of these two quantities on behavior transmission. In order to make the model closer to the real situation, self-motivation value and neighbor influence value are added to the behavior motivation value. Compared with previous studies, our proposed experimental model is closer to the real world, improves the possibility of behavior prediction, and is validated by simulation. Finally, this paper takes Lanzhou Polytechnic University campus cartoon consumption data as an example to test and validate the model.

Much of the allocation of human resources to tasks is studied under the rubric of "attention". However this is a very low-dimensional characterization of a system that has many degrees of freedom. To make progess in understanding human brain resource allocations, we will need to understand its basic functions at an abstract level. One way of accomplishing such an integration is to create a model of a human that has a useful amount of complexity. Essentially, one is faced with proposing an embodied "operating system" model that can be tested against human performance. Recently, technological advances have been made that allow progress in this direction. Graphic models that simulate extensive human capabilities can be used as platforms to develop synthetic models of visuo-motor behavior. Currently, such models can capture only a small portion of a full behavioral repertoire, but for the behaviors that they do model, they can describe complete visuo-motor subsystems at a level of detail that can be tested against human performance in realistic environments. This paper outlines one such model and shows both that it can produce interesting new hypotheses as to the role of vision and also that it can greatly enhance our understanding of a more multifacted characterization attention in visuo-motor tasks.

Zebrafish is emerging as a species of choice in alcohol-related pharmacological studies. In these studies, zebrafish are often exposed to acute ethanol treatments and their activity scored during behavioral assays. Computational modeling of zebrafish behavior is expected to positively impact these efforts by offering a predictive toolbox to plan hypothesis-driven studies, reduce the number of subjects, perform pilot trials, and refine behavioral screening. In this work, we demonstrate the use of the recently proposed jump persistent turning walker to model the turning rate dynamics of zebrafish exposed to acute ethanol administration. This modeling framework is based on a stochastic mean reverting jump process to capture the sudden and large changes in orientation of swimming zebrafish. The model is calibrated on an available experimental dataset of 40 subjects, tested at different ethanol concentrations. We demonstrate that model parameters are modulated by ethanol administration, whereby both the relaxation rate and jump frequency of the turning rate dynamics are influenced by ethanol concentration. This effort offers a first evidence for the possibility of complementing zebrafish pharmacological research with computational modeling of animal behavior.

Components should provide variability in satisfying a variety of domains [1], but it is not easy to develop components which can be applied to all domains. For this reason, when using time-to-market, components are slow and reusability of the components decreases. Hence, providing the variability of components becomes an important prerequisite for a successful component-based application development project.

In this paper, we propose a variability design technique that can satisfy the requirements of many different kinds of domains. This technique addresses a method for designing the variability of the behavior and the workflow in a more detailed manner, and uses an object-oriented mechanism and design patterns. One of the most important goals of this technique is to provide a practical method which can be effectively applied to component-based application development.

Model Checking based verification techniques represent an important issue in the field of concurrent systems quality assurance. The lack of formal semantics in the existing formalisms describing multi-agents models combined with multi-agents systems complexity are sources of several problems during their development process. The Maude language, based on rewriting logic, offers a rich notation supporting formal specification and implementation of concurrent systems. In addition to its modeling capacity, the Maude environment integrates a Model Checker based on Linear Temporal Logic (LTL) for distributed systems verification. In this paper, we present a formal and generic framework (DIMA-Maude) supporting formal description and verification of DIMA multi-agents models.

The use of common rhea, Rhea americana, as breeding bird requires knowledge of nutritional physiology. It is important the analysis jointly of feed intake, behavior and weight gain. Our objective was to determine and analyze differences in the feed intake, weight gained and behavior of captive subadults and adults male and female rheas during autumn and winter in the Humid Pampas, Argentina. Neither males nor females showed significant seasonal differences in the weights with which they initiated the trials. Daily feed consumption didn't show significant differences neither between seasons nor between sexes. However, we observed differences in weight gain by males between seasons and during the autumn trial, the weight gain was higher for males. Rhea behavior also varied seasonally. Males and females spent more time preening and resting than walking and feeding during autumn, the opposite occurred in winter. The males had a higher tendency towards walking than to feeding, the females showed the opposite in autumn. Analyzing the feed intake, weight gained and the time spent on feeding we hypothesized that males are more efficient for feeding. This analysis allowed us to observe there are nutritional issues that can be explained from a behavioral point of view.

This paper addresses the issue of automatic service composition. We first develop a framework in which the exported behavior of a service is described in terms of a so-called execution tree, that is an abstraction for its possible executions. We then study the case in which such exported behavior (i.e. the execution tree of the service) can be represented by a finite state machine (i.e. finite state transition system). In this specific setting, we devise sound, complete and terminating techniques both to check for the existence of a composition, and to return a composition, if one exists. We also analyze the computational complexity of the proposed algorithms. Finally, we present an open source prototype tool, called (E-Service Composer), that implements our composition technique. To the best of our knowledge, our work is the first attempt to provide a provably correct technique for the automatic synthesis of service composition, in a framework where the behavior of services is explicitly specified.

SINGAPORE – NUS Researchers Uncover Potent Parasite-killing Mechanism of Nobel Prize-Winning Anti-Malarial Drug.

SINGAPORE – Robotic Glove Invented by NUS Researchers Helps Patients Restore Hand Movements.

UNITED STATES – Study Reveals Environment, Behavior Contribute to Some 80 Percent of Cancers.

UNITED STATES – Probing the Mystery of How Cancer Cells Die.

UNITED STATES – Liver Hormone Works Through Brain's Reward Pathway to Reduce Preference for Sweets & Alcohol.

UNITED STATES – How Three Genes You've Never Heard of May Influence Human Fertility.

UNITED STATES – Researchers Find Link between Processed Foods and Autoimmune Diseases.

UNITED KINGDOM – Is Evolution More Intelligent Than We Thought?

UNITED KINGDOM – Unravelling the Genetics of Pregnancy and Heart Failure.

SWITZERLAND – New Global Framework to Eliminate Rabies.

CANADA – Droughts Hit Cereal Crops Harder Since 1980s.

TAIWAN – Discovery of Key Autophagy Terminator that Contributes to Cell Survival and Muscle Homeostasis.

Restricting the analysis to general 2×2 coordination games, this article shows how under certain conditions, it is highly likely that individuals coordinate on a (pay-off) efficient through risk inferior convention. This contrasts with other equilibrium refinement criteria, such as risk dominance or stochastic stability. Here it is assumed that players are situated on a toroidal regular lattice, interact only locally and, in each period, imitate the last period's most successful player in their neighborhood. If the set of observable players by an individual and the set that he interacts with are both identical and small, pay-off dominance plays the major role in defining the long-term convention. As the latter set of players increases, a risk dominant but pay-off inferior convention becomes more likely. The model also shows that the interaction of two player types in a nonsymmetric game potentially leads to nonegalitarian conventions.

Gamma oscillations (40–100 Hz), originally seen in the olfactory bulb (OB), have long been a defining characteristic of sensory coding in the olfactory system. This study proposes that gamma oscillations are of two types, associated with different behavioral features and synaptic origins within the OB. Local field potentials were recorded from rat and mouse OBs during various behavioral periods (immobility, alert motionlessness, exploration and odor discrimination). High frequency gamma activity (65–100 Hz) is shown to be correlated with the sniff cycle, initiated at the peak of inhalation and is called type 1 gamma. It is prominent during exploratory behavior, but also present during resting and trained odor discrimination. Low frequency gamma activity (35–65 Hz), called type 2 gamma, is not strongly correlated with the sniff cycle, is inhibited by the sniff onset and is prominent during alert immobility. Rest and alert immobility are characterized by alternating type 1 and type 2 gamma rhythms, while exploratory sniffing and odor discrimination show a dramatic decrease in type 2 gamma with a broadband increase in the power of type 1 gamma. Periods of alert immobility prior to odor discrimination in trained animals show dominance of type 2 gamma, with episodes lasting up to 0.5 second. Data from mice with selective deletion of granule cell inhibition in the OB show a selective loss of type 2 gamma with type 1 gamma dramatically enhanced during exploratory behavior, suggesting that mutual inhibition between granule cells or centrifugal inhibitory input drives type 2 gamma, and that the excitatory-inhibitory connections between mitral and granule cells likely drive type 1 gamma. Gamma activity is not a single type of oscillation, and the largest amplitude gamma bursts are often those associated with an attentive cognitive state rather than odor sniffing.

SK channels are responsible for long-lasting hyperpolarization following action potential and contribute to the neuronal integration signal. This study evaluates the involvement of SK channels on learning and memory in rats, by comparing the effects of two SK channel blockers, i.e., apamin which recognizes SK2 and SK3 channels, and lei-Dab7 which binds SK2 channels only. lei-Dab7 totally competes and contests apamin binding on whole brain sections (IC₅₀: 11.4 nM). Using an olfactory associative task, intracerebroventricular blocker injections were tested on reference memory. Once the task was mastered with one odor pair, it was then tested with a new odor pair. Apamin (0.3 ng), injected before or after the acquisition session, improved new odor pair learning in a retention session 24 hours later, whereas lei-Dab7 (3 ng) did not significantly affect the mnesic processes. These results indicated that the blockage of SK channels by apamin facilitates consolidation on new odor associations; lei-Dab7, containing only SK2 subunits, remains without effect suggesting an involvement of SK3 channels in the modulation of the mnesic processes.

The present study sought to determine a profile of integrated behavioral, brain and autonomic alterations in PTSD. Previous findings suggest that PTSD is associated with changes across electrophysiological (EEG and ERP), autonomic and cognitive/behavioral measures. In particular, PTSD has been associated with reduced cognitive performance, altered cortical arousal (measured by EEG), diminished late ERP component to oddball task targets (reduced P3 amplitude) and increased autonomic arousal relative to healthy controls. The present study examined measures of cognitive function, auditory oddball ERP components, autonomic function (heart rate and skin conductance) and EEG during resting conditions in 44 individuals with PTSD and 44 non-trauma-exposed controls, and predicted that an integrated profile of changes across a number of these measures would show a high level of sensitivity and specificity in discriminating PTSD from controls. Nine variables showing strongly significant (p < 0.002) between-group differences were entered into a discriminant function analysis. Four of these measures successfully discriminated the PTSD and non-PTSD groups: change in tonic arousal, duration of attention switching, working memory reaction time and errors of commission during visuospatial maze learning. Tonic arousal change contributed the most variance in predicting group membership. These results extend previous findings and provide an integrated biomarker profile that characterizes both PTSD and non-PTSD groups with a high degree of sensitivity and specificity. This outcome provides a platform for future studies to test how this profile of disturbances in autonomic and information processing may be unique to PTSD or may occur generically across clinical and/or other anxiety disorders.

Both the International Labor Organization (ILO) and the World Health Organization (WHO) concur that occupational health and safety in Africa needs strengthening. In support of this realization are the need to maintain and promote workers' health and working capacity, and the need to become conducive to safety and health by improving both the working environment and work. The fight against HIV and AIDS in the workplace is a continental priority. In the absence of any other definitive or similar study, this study aims to establish a valid baseline assessment of the levels of knowledge, types of attitudes, perceptions and beliefs of construction workers in South Africa regarding HIV infection and AIDS. It performs both a descriptive function with respect to how many workers have correct knowledge regarding AIDS and HIV and a predictive function in terms of how knowledge, attitudes, perceptions, beliefs, behaviors and certain biographical traits relate to one another. This paper examines the attitudes and perceptions of HIV and AIDS among construction workers as determined during the first phase of an exploratory study commenced in August 2002.

This paper addresses the influence of academic education and formal training on Project Managers' (PM) behavior. A survey was conducted to assess how PMs' academic education and formal training influence their behavior. The results have provided evidence that PMs with Engineering qualifications and background tend to be more technically oriented. This may raise concerns that PMs pre-occupation with the technical aspects of project management may overshadow the need for them to pay more attention to people management. However, PMs with the experience of working on projects at the "operational" level have been less technically oriented. Such experience seems to have enhanced PMs motivational and conflict management skills. These results highlight the need for academic and professional development programmes to provide the right balance, in content and emphasize, between the technical knowledge and the people management skills for young professionals to take project management responsibilities.

Plasmodium of Physarum polycephalum is a single cell visible by unaided eye, which spans sources of nutrients with its protoplasmic network. In a very simple experimental setup we recorded electric potential of the propagating plasmodium. We discovered a complex interplay of short range oscillatory behavior combined with long range, low frequency oscillations which serve to communicate information between different parts of the plasmodium. The plasmodium's response to changing environmental conditions forms basis patterns of electric activity, which are unique indicators of the following events: plasmodium occupies a site, plasmodium functions normally, plasmodium becomes "agitated" due to drying substrate, plasmodium departs a site, and plasmodium forms sclerotium. Using a collective particle approximation of Physarum polycephalum we found matching correlates of electrical potential in computational simulations by measuring local population flux at the node positions, generating trains of high and low frequency oscillatory behavior. Motifs present in these measurements matched the response "grammar" of the plasmodium when encountering new nodes, simulated consumption of nutrients, exposure to simulated hazardous illumination and sclerotium formation. The distributed computation of the particle collective was able to calculate beneficial network structures and sclerotium position by shifting the active growth zone of the simulated plasmodium. The results show future promise for the non-invasive study of the complex dynamical behavior within — and health status of — living systems.

Shanahan's work admirably and convincingly supports Baars' global workspace by means of plausible and updated neural models. Yet little of his work is related with the issue of consciousness as phenomenal experience. He focuses his effort mostly on the behavioral correlates of consciousness like autonomy, flexibility, and information integration. Moreover, although the importance of embodiment and situated cognition is emphasized, most of the conceptual tools suggested (dynamic systems, complex networks, global workspace) require the external world only during their development. Leaving aside the issue of phenomenal experience, the book fleshes out a convincing and thought-provoking model for many aspects of conscious behaviour.

Information provided by the US Department of Homeland Security regarding potential terrorist attacks significantly affects US Treasury securities markets. When the government announces heightened terror alert levels, investors' perceptions of risk increase and investors purchase 1-month and 1-year Treasury bills and 3-year, 5-year, 7-year, and 10-year US Treasuries in a "flight-to-quality" episode. Partial anticipation of increased threat level announcements is stronger than the anticipation of announcements regarding the federal funds rate during the 10 days prior to an announcement.

Entrepreneurial skills enable people to develop new business ideas or improve existing ones. Entrepreneurship transcends firm ownership, private profit production, and the commercial exploitation of new markets, goods, or processes. The literature review demonstrates how competencies are linked with entrepreneur performance. The primary goal of this study was to evaluate the role of entrepreneurs’ competency in mediating the relationship between bank funding and Small and Medium Enterprisers (SMEs’) performance. A survey was conducted among 398 SMEs owner-managers were chosen at random. The direct and mediated effects of entrepreneurs’ competency were not significant in the Factor Analysis and Structural Equation Model. However, bank financing improves SMEs’ performance. A strong mediation influence of behavioral Finance on the connection between bank loans and SMEs performance was also found. The model’s competitive mediation pattern for bank loans and behavioral finance was non-mediation for bank loans and entrepreneurs’ skill.

This article has been retracted.