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Face-to-faceinteractionnetworks describe social interactions in human gatherings, and are the substrate for processes such as epidemic spreading and gossip propagation. The bursty nature of human behavior characterizes many aspects of empirical data, such as the distribution of conversation lengths, of conversations per person, or of interconversation times. Despite several recent attempts, a general theoretical understanding of the global picture emerging from data is still lacking. Here we present a simple model that reproduces quantitatively most of the relevant features of empirical face-to-faceinteractionnetworks. The model describes agents that perform a random walk in a two-dimensional space and are characterized by an attractiveness whose effect is to slow down the motion of people around them. The proposed framework sheds light on the dynamics of human interactions and can improve the modeling of dynamical processes taking place on the ensuing dynamical social networks.
Face-to-faceinteractionnetworks describe social interactions in human gatherings, and are the substrate for processes such as epidemic spreading and gossip propagation. The bursty nature of human behavior characterizes many aspects of empirical data, such as the distribution of conversation lengths, of conversations per person, or of interconversation times. Despite several recent attempts, a general theoretical understanding of the global picture emerging from data is still lacking. Here we present a simple model that reproduces quantitatively most of the relevant features of empirical face-to-faceinteractionnetworks. The model describes agents that perform a random walk in a two-dimensional space and are characterized by an attractiveness whose effect is to slow down the motion of people around them. The proposed framework sheds light on the dynamics of human interactions and can improve the modeling of dynamical processes taking place on the ensuing dynamical social networks. PMID:23679648
The ever increasing adoption of mobile technologies and ubiquitous services allows to sense human behavior at unprecedented level of details and scale. Wearable sensors, in particular, open up a new window on human mobility and proximity in a variety of indoor environments. Here we review stylized facts on the structural and dynamical properties of empirical networks of human face-to-face proximity, measured in three different real-world contexts: an academic conference, a hospital ward, and a museum exhibition. First, we discuss the structure of the aggregated contact networks, that project out the detailed ordering of contact events while preserving temporal heterogeneities in their weights. We show that the structural properties of aggregated networks highlight important differences and unexpected similarities across contexts, and discuss the additional complexity that arises from attributes that are typically associated with nodes in real-world interactionnetworks, such as role classes in hospitals. We then consider the empirical data at the finest level of detail, i.e., we consider time-dependent networks of face-to-face proximity between individuals. To gain insights on the effects that causal constraints have on spreading processes, we simulate the dynamics of a simple susceptible-infected model over the empirical time-resolved contact data. We show that the spreading pathways for the epidemic process are strongly affected by the temporal structure of the network data, and that the mere knowledge of static aggregated networks leads to erroneous conclusions about the transmission paths on the corresponding dynamical networks.
Barrat, A.; Cattuto, C.; Colizza, V.; Gesualdo, F.; Isella, L.; Pandolfi, E.; Pinton, J.-F.; Ravà, L.; Rizzo, C.; Romano, M.; Stehlé, J.; Tozzi, A. E.; Van den Broeck, W.
The ever increasing adoption of mobile technologies and ubiquitous services allows to sense human behavior at unprecedented levels of details and scale. Wearable sensors are opening up a new window on human mobility and proximity at the finest resolution of face-to-face proximity. As a consequence, empirical data describing social and behavioral networks are acquiring a longitudinal dimension that brings forth new challenges for analysis and modeling. Here we review recent work on the representation and analysis of temporal networks of face-to-face human proximity, based on large-scale datasets collected in the context of the SocioPatterns collaboration. We show that the raw behavioral data can be studied at various levels of coarse-graining, which turn out to be complementary to one another, with each level exposing different features of the underlying system. We briefly review a generative model of temporal contact networks that reproduces some statistical observables. Then, we shift our focus from surface statistical features to dynamical processes on empirical temporal networks. We discuss how simple dynamical processes can be used as probes to expose important features of the interaction patterns, such as burstiness and causal constraints. We show that simulating dynamical processes on empirical temporal networks can unveil differences between datasets that would otherwise look statistically similar. Moreover, we argue that, due to the temporal heterogeneity of human dynamics, in order to investigate the temporal properties of spreading processes it may be necessary to abandon the notion of wall-clock time in favour of an intrinsic notion of time for each individual node, defined in terms of its activity level. We conclude highlighting several open research questions raised by the nature of the data at hand.
Research on link prediction for social networks has been actively pursued. In link prediction for a given social network obtained from time-windowed observation, new link formation in the network is predicted from the topology of the obtained network. In contrast, recent advances in sensing technology have made it possible to obtain face-to-face behavioral networks, which are social networks representing face-to-faceinteractions among people. However, the effectiveness of link prediction techniques for face-to-face behavioral networks has not yet been explored in depth. To clarify this point, here we investigate the accuracy of conventional link prediction techniques for networks obtained from the history of face-to-faceinteractions among participants at an academic conference. Our findings were (1) that conventional link prediction techniques predict new link formation with a precision of 0.30–0.45 and a recall of 0.10–0.20, (2) that prolonged observation of social networks often degrades the prediction accuracy, (3) that the proposed decaying weight method leads to higher prediction accuracy than can be achieved by observing all records of communication and simply using them unmodified, and (4) that the prediction accuracy for face-to-face behavioral networks is relatively high compared to that for non-social networks, but not as high as for other types of social networks.
The present study compared the relative impact of peer-mentoring that took place either face-to-face or through electronic chat. Proteges were 106 college freshmen randomly assigned to a senior college student mentor and to one of the two communication modes. Fifty-one mentors interacted with one of these proteges face-to-face and one solely…
Smith-Jentsch, Kimberly A.; Scielzo, Shannon A.; Yarbrough, Charyl S.; Rosopa, Patrick J.
Recent years have witnessed the birth of a new paradigm for learning environments: animated pedagogical agents. These lifelike autonomous characters cohabit learning environments with students to create rich, face-to-face learning interactions. This opens up exciting new possibilities; for example, agents can demonstrate complex tasks, employ locomotion and gesture to focus students' attention on the most salient aspect of the task
While interaction in online language learning in the area of written computer-mediated communication is well researched, studies focusing on interaction in synchronous online audio environments remain scarce. For this reason, this paper seeks to map the nature and level of interpersonal interaction in both online and the face-to-face language…
We present a series of experiments that involve a face-to-faceinteraction between an embodied conversational agent (ECA) and a human interlocutor. The main challenge is to provide the interlocutor with implicit and explicit signs of mutual interest and attention and of the awareness of environmental conditions in which the interaction takes place. A video realistic talking head with independent head
This article describes the use of microanalysis of videotapes to look at nonverbal elements (such as smiles, facial expressions, eye gaze, touch, and head and body movements toward and away from the other) to determine the caregiver-infant interactive (regulatory) experience. Video microanalysis of face-to-face play by infants and parents…
Compares discourse management strategies in face-to-face and computer-mediated interactions involving four decision-making tasks. Examines these issues in qualitative and quantitative analyses of data using an utterance-unit coding system to identify discourse functions. Finds that participants compensate for decreased efficiency by adopting…
In today's second language classrooms, students are often asked to work in pairs or small groups. Such collaboration can take place face-to-face, but now more often via computer mediated communication. This paper reports on a study which investigated the effect of the medium of communication on the nature of pair interaction. The study involved…
Tan, Lan Liana; Wigglesworth, Gillian; Storch, Neomy
This study seeks to understand the role of the Internet in quality of life (QoL). Specifically, it examines the question of whether Internet communication serves, like face-to-faceinteractions, to enhance quality of life. It is hypothesized that the use of the Internet for interpersonal communication can improve quality of life among Internet…
Lee, Paul S. N.; Leung, Louis; Lo, Venhwei; Xiong, Chengyu; Wu, Tingjun
This study investigated how synchronous computer-mediated communication (SCMC) and face-to-face (F2F) oral interaction influence the way in which learners collaborate in language learning and how they solve their communicative problems. The findings suggest that output modality may affect how learners produce language, attend to linguistic forms,…
Patients with a diagnosis of schizophrenia display social cognitive deficits. However, little is known about patients' nonverbal communication during their social encounters with others. This review identified 17 studies investigating nonverbal communication in patients' unscripted face-to-faceinteractions, addressing a) nonverbal differences between patients and others, b) nonverbal behavior of the patients' partners, c) the association between nonverbal behavior and symptoms, and d) the association between nonverbal behavior and social outcomes. Patients displayed fewer nonverbal behaviors inviting interaction, with negative symptoms exacerbating this pattern. Positive symptoms were associated with heightened nonverbal behavior. Patients' partners changed their own nonverbal behavior in response to the patient. Reduced prosocial behaviors, inviting interaction, were associated with poorer social outcomes. The evidence suggests that patients' nonverbal behavior, during face-to-faceinteraction, is influenced by patients symptoms and impacts the success of their social interactions. PMID:24375212
Lavelle, Mary; Healey, Patrick G T; McCabe, Rosemarie
This article examines the degrees of collaborative language learning that were supported in cyber face-to-faceinteraction. The concept of "cyber face-to-face" is used here to encapsulate the kind of environment in which a combination of real-time oral/aural, visual, and text-based interaction happens simultaneously via the various features in an…
This study investigates the impact of anonymous, computerized, synchronized team competition on students' motivation, satisfaction, and interpersonal relationships. Sixty-eight fourth-graders participated in this study. A synchronous gaming learning system was developed to have dyads compete against each other in answering multiple-choice questions set in accordance with the school curriculum in two conditions (face-to-face and anonymous). The results showed that students who were exposed to the anonymous team competition condition responded significantly more positively than those in the face-to-face condition in terms of motivation and satisfaction at the 0.050 and 0.056 levels respectively. Although further studies regarding the effects of anonymous interaction in a networked gaming learning environment are imperative, the positive effects detected in this preliminary study indicate that anonymity is a viable feature for mitigating the negative effects that competition may inflict on motivation and satisfaction as reported in traditional face-to-face environments. PMID:18721101
Cooperative social interaction is critical for human social development and learning. Despite the importance of social interaction, previous neuroimaging studies lack two fundamental components of everyday face-to-faceinteractions: contingent responding and joint attention. In the current studies, functional MRI data were collected while participants interacted with a human experimenter face-to-face via live video feed as they engaged in simple cooperative
Elizabeth Redcay; David Dodell-Feder; Mark J. Pearrow; Penelope L. Mavros; Mario Kleiner; John D. E. Gabrieli; Rebecca Saxe
The cooperative control of coordinate-covalent bonds, strong hydrogen bonds and perfect face-to-face ?…? stacking interactions leads to a new Cu(II) coordination polymer with unusual doubly interpenetrated (3,5)-connected hms topology.
We investigated the relationship between team empowerment and virtual team performance and the moderating role of the extent of face-to-faceinteraction using 35 sales and service virtual teams in a high-technology organization. Team empowerment was positively related to two independent assessments of virtual team performance— process improvement and customer satisfaction. Further, the number of face-to-face meetings moderated the relationship between
Bradley L. Kirkman; BENSON ROSEN; PAUL E. TESLUK; CRISTINA B. GIBSON
Humans often watch interactions between other people without taking part in the interaction themselves. Strikingly little is, however, known about how gestures and expressions of two interacting humans are processed in the observer's brain, since the study of social cues has mostly focused on the perception of solitary humans. To investigate the neural underpinnings of the third-person view of social interaction, we studied brain activations of subjects who observed two humans either facing toward or away from each other. Activations within the amygdala, posterior superior temporal sulcus (pSTS), and dorsomedial prefrontal cortex (dmPFC) were sensitive to the interactional position of the observed people and distinguished humans facing toward from humans facing away. The amygdala was most sensitive to face-to-faceinteraction and did not differentiate the humans facing away from the pixelated control figures, whereas the pSTS dissociated both human stimuli from the pixel figures. The results of the amygdala reactivity suggest that, in addition to regulating interpersonal distance towards oneself, the amygdala is involved in the assessment of the proximity between two other persons. PMID:21674692
Mobile computers are now increasingly applied to facilitate face-to-face collaborative learning. However, the factors affecting face-to-face peer interactions are complex as they involve rich communication media. In particular, non-verbal interactions are necessary to convey critical communication messages in face-to-face communication. Through…
We present a series of experiments that involve a face-to-faceinteraction between an embodied conversational agent (ECA) and a human interlocutor. The main challenge is to provide the interlocutor with implicit and explicit signs of mutual interest and attention and of the awareness of environmental conditions in which the interaction takes place. A video realistic talking head with independent head
The study attempts to measure the effects of self-esteem and face-to-faceinteraction on a person's giving behavior (altruism). Seventy-two introductory psychology students were paired on a task which required that one of each pair become "indebted" to the other. Their roles were then reversed, and data was collected to see if the…
This study proposes a new method named the IIS-map-based method for analyzing interactions in face-to-face collaborative learning settings. This analysis method is conducted in three steps: firstly, drawing an initial IIS-map according to collaborative tasks; secondly, coding and segmenting information flows into information items of IIS; thirdly,…
In this paper, we present an AR framework that allows natural hand and tangible AR interaction for physically-based interaction and environment awareness to support face-to-face collaboration using Microsoft Kinect. Our framework comprises of six major components: (1) marker tracking (2) depth acquisition (3) image processing (4) physics simulation (5) communication and (6) rendering. The resulting augmented environment supports occlusion, shadows,
Thammathip Piumsomboon; Adrian Clark; Atsushi Umakatsu; Mark Billinghurst
Compound ([FeTPPbipy](•))n (TPP = meso-tetraphenylporphyrin and bipy = 4,4'-bipyridine) is the first example of a Fe-TPP-bipy coordination network, and it consists of 1D polymers packed through face-to-face and edge-to-face ?-? interactions. The compound has been investigated by means of X-ray diffraction, IR, Mössbauer, UV-visible, and EPR spectroscopies, thermogravimetry, magnetic susceptibility measurements, and quantum-mechanical density functional theory (DFT) and time-dependent DFT calculations. The chemical formula for this compound can be confusing because it is compatible with Fe(II) and TPP(2-) anions. However, the spectroscopic and magnetic properties of this compound are consistent with the presence of low-spin Fe(III) ions and [FeTPPbipy](•) neutral radicals. These radicals are proposed to be formed by the reduction of metalloporphyrin, and the quantum-mechanical calculations are consistent with the fact that the acquired electrons are located on the phenyl groups of TPP. PMID:23799787
The objective of the study is to use social network analysis to examine the acceptability of a youth-led, hybrid face-to-face and online social networking HIV prevention program for homeless youth. Seven peer leaders (PLs) engaged face-to-face homeless youth (F2F) in the creation of digital media projects (e.g. You Tube videos). PL and F2F…
Online social games are Internet-based games that use the social networks formed by players to extend in-game functionality. For example, gamers participating in the BBO Fans community combine online bridge play with social networking. Despite an increase in the popularity of online social gaming---currently, there exist over one million online bridge players---, and of decades of research on social networks,
Mihaela Balint; Vlad Posea; Alexandru Dimitriu; Alexandru Iosup
This study investigates the differential effects of CMC interaction (both text-chat and voice-chat) and face-to-faceinteractions on university level of ESL students' vocabulary acquisition. More specifically, this study examines (a) whether learners engage in negotiated interaction when they encounter new lexical items, (b) whether CMC interaction help learners acquire new lexical items productively, (c) whether there are any special features
The purpose of this study was to examine 32 mothers' sensitivity to social contingency during face-to-faceinteraction with their two- to four-month-old infants in a closed circuit TV set-up. Prosodic qualities and vocal sounds in mother's infant-directed (ID) speech during sequences of live interaction were compared to sequences where expressive…
Persons with autism spectrum disorders (ASD) are known to have difficulty in eye contact (EC). This may make it difficult for their partners during facetoface communication with them. To elucidate the neural substrates of live inter-subject interaction of ASD patients and normal subjects, we conducted hyper-scanning functional MRI with 21 subjects with autistic spectrum disorder (ASD) paired with typically-developed (normal) subjects, and with 19 pairs of normal subjects as a control. Baseline EC was maintained while subjects performed real-time joint-attention task. The task-related effects were modeled out, and inter-individual correlation analysis was performed on the residual time-course data. ASD-Normal pairs were less accurate at detecting gaze direction than Normal-Normal pairs. Performance was impaired both in ASD subjects and in their normal partners. The left occipital pole (OP) activation by gaze processing was reduced in ASD subjects, suggesting that deterioration of eye-cue detection in ASD is related to impairment of early visual processing of gaze. On the other hand, their normal partners showed greater activity in the bilateral occipital cortex and the right prefrontal area, indicating a compensatory workload. Inter-brain coherence in the right IFG that was observed in the Normal-Normal pairs (Saito et al., 2010) during EC diminished in ASD-Normal pairs. Intra-brain functional connectivity between the right IFG and right superior temporal sulcus (STS) in normal subjects paired with ASD subjects was reduced compared with in Normal-Normal pairs. This functional connectivity was positively correlated with performance of the normal partners on the eye-cue detection. Considering the integrative role of the right STS in gaze processing, inter-subject synchronization during EC may be a prerequisite for eye cue detection by the normal partner. PMID:23060772
Social anxiety occurs in a range of social situations, the salience of which is influenced by prevailing modes of social contact. The emergence of computer mediated communication (CMC), buoyed by the recent explosion of social networks, has changed the way many people make and maintain social contacts. We randomly assigned 30 socially anxious and 30 low social anxiety participants to a brief internet chat introduction or a control internet surfing condition followed by a standardized facetoface (FTF) interaction. We hypothesized that for socially anxious participants the chat introduction would reduce anxiety of and preference to avoid the subsequent FTF interaction. Results supported hypotheses for most indices. Findings suggest that, at least for the common situation in which internet chat precedes FTF interaction with the same person, such contact may reduce social anxiety. It is not known whether this decrease would generalize to FTF contact in other contexts. It is suggested that CMC might be construed as a particularly useful form of safety behavior that may help in the allocation of attentional resources to process new information relevant for disconfirmation of negative beliefs maintaining social anxiety. Potential clinical implications are discussed. PMID:22466023
Markovitzky, Omer; Anholt, Gideon E; Lipsitz, Joshua D
Many new and important developmental issues are encountered during adolescence, which is also a time when Internet use becomes increasingly popular. Studies have shown that adolescents are using these online spaces to address developmental issues, especially needs for intimacy and connection to others. Online communication with its potential for interacting with unknown others, may put teens at increased risk. Two hundred and fifty-one high school students completed an in-person survey, and 126 of these completed an additional online questionnaire about how and why they use the Internet, their activities on social networking sites (e.g., Facebook, MySpace) and their reasons for participation, and how they perceive these online spaces to impact their friendships. To examine the extent of overlap between online and offline friends, participants were asked to list the names of their top interaction partners offline and online (Facebook and instant messaging). Results reveal that adolescents mainly use social networking sites to connect with others, in particular with people known from offline contexts. While adolescents report little monitoring by their parents, there was no evidence that teens are putting themselves at risk by interacting with unknown others. Instead, adolescents seem to use the Internet, especially social networking sites, to connect with known others. While the study found moderate overlap between teens' closest online and offline friends, the patterns suggest that adolescents use online contexts to strengthen offline relationships. PMID:22369341
Reich, Stephanie M; Subrahmanyam, Kaveri; Espinoza, Guadalupe
A B3LYP/6-31G(d,p) and MP2/6-31G(d,p)//B3LYP/6-31G(d,p) computational study of the gas-phase complexation of cyclobis(paraquat-p-phenylene) (1(4+)) with four typical aromatic guests, namely, 1,4-dimethoxybenzene (2), 1,5-dimethoxynaphthalene (3), benzidine (4), and tetrathiafulvalene (5), has been carried out. The structure of the host has been successively split into two responsible substructures, respectively, for the face-to-face and edge-to-face interactions with the guests. The sum of the two interactions calculated at the B3LYP/6-31G(d,p) and MP2/6-31G(d,p)//B3LYP/6-31G(d,p) levels for each guest proved to be in good agreement with the overall binding energy of the host calculated at the corresponding level of theory. The results show that the binding of the complexes is primarily due to London dispersion interactions which require wave function-based correlation methods for an adequate description. Face-to-faceinteractions are about 1 order of magnitude more important than edge-to-face interactions in determining the overall binding energy. While edge-to-face interactions essentially depend on London dispersion forces, face-to-faceinteractions depend about one-half on electrostatic and frontier orbital contributions (the latter being more important) and the other half on London dispersion forces. PMID:12895093
Individuals are embedded in social networks in which they communicate with others in their daily lives. Because smooth face-to-face communication is the key to maintaining these networks, measuring the smoothness of such communication is an important issue. One indicator of smoothness is the similarity of the body movements of the two individuals concerned. A typical example noted in experimental environments is the interpersonal synchronization of body movements such as nods and gestures during smooth face-to-face communication. It should therefore be possible to estimate quantitatively the smoothness of face-to-face communication in social networks through measurement of the synchronization of body movements. However, this is difficult because social networks, which differ from disciplined experimental environments, are open environments for the face-to-face communication between two individuals. In such open environments, their body movements become complicated by various external factors and may follow unstable and nonuniform patterns. Nevertheless, we consider there to be some interaction during face-to-face communication that leads to the interpersonal synchronization of body movements, which can be seen through the interpersonal similarity of body movements. The present study aims to clarify such interaction in terms of body movements during daily face-to-face communication in real organizations of more than 100 people. We analyzed data on the frequency of body movement for each individual during face-to-face communication, as measured by a wearable sensor, and evaluated the degree of interpersonal similarity of body movements between two individuals as their frequency difference. Furthermore, we generated uncorrelated data by resampling the data gathered and compared these two data sets statistically to distinguish the effects of actual face-to-face communication from those of the activities accompanying the communication. Our results confirm an interpersonal similarity of body movements between two individuals in face-to-face communication, for all the organizations studied, and suggest that some body interaction is behind this similarity.
Contact behaviours such as touch, have been shown to be influential channels of nonverbal communication between mothers and infants. While existing research has examined the communicative roles of maternal or infant touch in isolation, mutual touch, whereby touching behaviours occur simultaneously between mothers and their infants, has yet to be examined. The present study was designed to investigate mutual touch during face-to-faceinteractions between mothers and their 5½-month-old fullterm (n=40), very low birth weight/preterm (VLBW/preterm; n=40) infants, and infants at psychosocial risk (n=41). Objectives were to examine: (1) how the quantitative and qualitative aspects of touch employed by mothers and their infants varied across the normal periods of the still-face (SF) procedure, and (2) how these were associated with risk status. Mutual touch was systematically coded using the mother-infant touch scale. Interactions were found to largely consist of mutual touch and one-sided touch plus movement, highlighting that active touching is pervasive during mother-infant interactions. Consistent with the literature, while the SF period did not negatively affect the amount of mutual touch engaged in for mothers and their fullterm infants and mothers and their infants at psychosocial risk, it did for mothers and their VLBW/preterm infants. Together, results illuminate how both mothers and infants participate in shaping and co-regulating their interactions through the use of touch and underscore the contribution of examining the influence of birth status on mutual touch. PMID:24793734
Mantis, Irene; Stack, Dale M; Ng, Laura; Serbin, Lisa A; Schwartzman, Alex E
Imagine being the size of an ant. Be careful - a face-to-face encounter with an ant would be scary and potentially life-threatening! But, if you avoided being eaten, you could learn a lot about ant anatomy from a close-up view. Ants have many body parts that are normally hard to see without a magnifying glass or microscope. And each structure has its own special function.
One-to-one computing environments change and improve classroom dynamics as individual students can bring handheld devices fitted with wireless communication capabilities into the classrooms. However, the screens of handheld devices, being designed for individual-user mobile application, limit promotion of interaction among groups of learners. This…
Examines the strategies people employ to deal with the face- and interaction-threatening implications of argumentative behavior. Explores the joint influence of individual differences in perceivers' interpersonal construct systems and message producers' communication strategies on the content and structure of impressions of message producers. (MS)
As human beings, we live in, live with, and live through our bodies. And because of this it is no wonder that our hands and bodies are in motion as we interact with others in our world. Hands and body move as we give directions to another, anticipate which way to turn the screwdriver, and direct our friend to come sit next to us. Gestures, indeed, fill our everyday lives. The purpose of this study is to investigate the functional role of the body in the parts of our lives where we teach and learn with another. This project is an investigation into, what I call, "interactive explanations". I explore how the hands and body work toward the joint achievement of explanation and learning in face-to-face arrangements. The study aims to uncover how the body participates in teaching and learning in and across events as it slides between the multiple, interdependent roles of (1) a communicative entity, (2) a tool for thinking, and (3) a resource to shape interaction. Understanding gestures functional roles as flexible and diverse better explains how the body participates in teaching and learning interactions. The study further aims to show that these roles and functions are dynamic and changeable based on the interests, goals and contingencies of participants' changing roles and aims in interactions, and within and across events. I employed the methodology of comparative microanalysis of pairs of videotaped conversations in which, first, experts in STEM fields (Science, Technology, Engineering and Mathematics) explained concepts to non-experts, and second, these non-experts re-explained the concept to other non-experts. The principle finding is that people strategically, creatively and collaboratively employ the hands and body as vital and flexible resources for the joint achievement of explanation and understanding. Findings further show that gestures used to explain complex STEM concepts travel across time with the non-expert into re-explanations of the concept. My analysis demonstrates that gestures and the body are complex, multi-functional resources that work toward cognitive, communicative, and interactional achievement and, as such, are viable resources for teaching and learning in face-to-faceinteraction.
This study investigates cultural and communication medium effects on conversational argumentation in a decision-making context. Chinese and U.S. participants worked in pairs on two decision-making tasks via face-to-face (FtF) and instant messaging (IM). The analyses showed that Chinese participants tended to engage in potentially more complex…
Stewart, Craig O.; Setlock, Leslie D.; Fussell, Susan R.
Face-to-face learning has been the mainstay of nursing student learning. Despite moves to online learning, face-to-face learning persists. This study focuses on how nursing students experience face-to-face learning and why it not only survives, but thrives. This study was anchored in a hermeneutic phenomenological approach, with Gadamerian concepts and van Manen's lifeworlds as frameworks to understand students' experiences of face-to-face learning. Patterns and themes were extracted from audiore-corded face-to-face interviews. Participants confirmed that face-to-face learning continues to be valued as a strong methodology in nursing education. Their experiences focused on humanism, the importance of "presence," physical proximity, classroom as "the real thing," immediacy of feedback, and learning and knowing by human connections and interaction. The study findings were a rich source for understanding how nursing students process learning experiences. Increased understanding of the meaning and essence of face-to-face learning is essential as we decide how nursing content will be taught. PMID:21956259
We describe here our first effort for developing a virtual talking head able to engage a situated face-to-faceinteraction with a human partner. This paper concentrates on the low-level components of this interaction loop and the cognitive impact of the implementation of mutual attention and multimodal deixis on the communication task.
This empirical study compared a graduate online course with an equivalent course taught in a traditional face-to-face format. Comparisons included student ratings of instructor and course quality; assessment of course interaction, structure, and support; and learning outcomes such as course grades and student self-assessment of ability to perform…
Johnson, Scott D.; Aragon, Steven R.; Shaik, Najmuddin; Palma-Rivas, Nilda
This paper investigates the motivational power of children to change teachers' beliefs about teaching. Weekly and summary reflections written by 18 preservice teachers served as data sources. Preservice teachers were learning from the children what they expect their teachers to know, to do, and to be, and in consequence of the face-to-face…
A comparison was made of the effectiveness of a programmed Self-Counseling Manual and a normal precollege counseling interview by experienced counselors. Findings supported the use of programmed counseling as an adjunct to or substitute for face-to-face counseling. (Author)
It has been reported that human face-to-face communications in space are compromised by facial edema, variations in the orientations of speakers and listeners, and background noises that are encountered in the shuttle and in space stations. To date, nearly all reports have been anecdotal or subjective, in the form of post-flight interviews or questionnaires; objective and quantitative data are generally lacking. Although it is acknowledged that efficient face-to-face communications are essential for astronauts to work safely and effectively, specific ways in which the space environment interferes with non-linguistic communication cues are poorly documented. Because we have only a partial understanding of how non-linguistic communication cues may change with mission duration, it is critically important to obtain objective data, and to evaluate these cues under well-controlled experimental conditions.
Cohen, Malcolm M.; Davon, Bonnie P. (Technical Monitor)
Most distributed work requires mediated communication, but the appropriate use of mediated, as compared with face-to-face communication, is not well understood. From our ethnographic research on workplace communication, we characterize unique aspects of face-to-face communication. Facetoface communication supports touch, shared activities, eating and drinking together, as well as informal interactions and attention management. We argue that these activities
Recent magneto-encephalographic and electro-encephalographic studies provide evidence for cross-modal integration during audio-visual and audio-haptic speech perception, with speech gestures viewed or felt from manual tactile contact with the speaker’s face. Given the temporal precedence of the haptic and visual signals on the acoustic signal in these studies, the observed modulation of N1/P2 auditory evoked responses during bimodal compared to unimodal speech perception suggest that relevant and predictive visual and haptic cues may facilitate auditory speech processing. To further investigate this hypothesis, auditory evoked potentials were here compared during auditory-only, audio-visual and audio-haptic speech perception in live dyadic interactions between a listener and a speaker. In line with previous studies, auditory evoked potentials were attenuated and speeded up during both audio-haptic and audio-visual compared to auditory speech perception. Importantly, the observed latency and amplitude reduction did not significantly depend on the degree of visual and haptic recognition of the speech targets. Altogether, these results further demonstrate cross-modal interactions between the auditory, visual and haptic speech signals. Although they do not contradict the hypothesis that visual and haptic sensory inputs convey predictive information with respect to the incoming auditory speech input, these results suggest that, at least in live conversational interactions, systematic conclusions on sensory predictability in bimodal speech integration have to be taken with caution, with the extraction of predictive cues likely depending on the variability of the speech stimuli.
In this chapter, the synthesis of new perfluoroalkylated hydrocarbon aromatics A) 1,2,4,5-tetrakis(nonafluorobutyl)-benzene (4-C4F 9-Bz), B) 1,3,6,8-tetrakis(nonafluorobutyl)-pyrene (4-C4F 9-pyrene) and two new heteroaromatic compounds C) 3,8-bis(nonafluorobutyl)-1,10-phenanthroline(2-C4F9-1,10-phen) and D) 4,4'-bis(nonafluorobutyl)-2,2'-bipyridine (2-C4F9-bipy) were described, using copper mediated perfluoroalkylation in a mixture of DMSO(anhy) and anhydrous benzotrifluoride (BTF(anhy)). All the compounds were purified by recrystallization and characterized by 1H NMR, 19F NMR, mass spectrometry and elemental analyses. Single-crystals were obtained for these novel compounds and their packing modes are studied and compared with other literature reporting single crystal structures to study the effects of substitution of electron deficient fluoroalkyl chains on aromatics on packing modes, and weak noncovalent interactions that became the basis for the present chapter. We found that by fine-tuning the size of the aromatic core, lengthening perfluoroalkyl chain, altering the substitution position, and making use of these weak fluorous interactions, 1-D pi-pi stacking in these model compounds is achieved. This can provide us an opportunity to extend this concept to n-type solution processable air-stable organic semiconductor molecules which can be used in real world applications.
The objective of this research was to compare the quality and quantity of teacher and student interaction in an on-line versus face-to-face learning environment. A Master's level course on nursing theories was taught by the same professor by both methods. Transcripts of the face-to-face class and on-line postings were analyzed to identify…
Prenatal cocaine and opiate exposure are thought to subtly compromise social and emotional development. The authors observed a large sample of 236 cocaine-exposed and 459 nonexposed infants (49 were opiate exposed and 646 nonexposed) with their mothers in the face-to-face still-face paradigm. Infant and maternal behaviors were microanalytically…
Tronick, E. Z.; Messinger, D. S.; Weinberg, M. K.; Lester, B. M.; LaGasse, L.; Seifer, R.; Bauer, C. R.; Shankaran, S.; Bada, H.; Wright, L. L.; Poole, K.; Liu, J.
We present an analysis of mobile face-to-face meeting support systems that reveal the consequences duration has for interaction through and with this technology in public places. Particularly we argue that there are privacy issues at stake. We base our arguments on empirical research concerning public interaction and disclosure of personal information there, seeing that face-to-face support systems add something to
Currently, many students have had experience with both face-to-face and online classes. We asked such students at 46 different universities in the United States to evaluate the pedagogical characteristics of their most recently completed face-to-face class and their most recently completed online class. The results show that students rate online…
Wuensch, Karl; Aziz, Shahnaz; Ozan, Erol; Kishore, Masao; Tabrizi, M. H. Nassehzadeh
This paper presents and discusses findings of a study conducted on pre-service teachers' experiences in virtual and facetoface discussions. Technology has brought learning nowadays beyond the classroom context or time zone. The learning context and process no longer rely solely on facetoface communications in the presence of a teacher.…
OBJECTIVE To assess the perceived effectiveness of tobacco cessation continuing education for pharmacists in face-to-face presentation versus live webinar modalities. METHODS A continuing pharmacy education (CPE) activity, Do Ask, Do Tell: A Practical Approach to Smoking Cessation, was offered in face-to-face and live webinar modalities. Following the activity, participants completed a brief questionnaire that assessed the anticipated impact of the activity on their smoking cessation counseling practices. RESULTS Of the 1,088 CPE participants, 819 (75%) attended a face-to-face presentation and 269 (25%) participated in a live webinar. Posttraining self-rated ability to address tobacco use was similar between groups ( P = 0.38), and both the face-to-face and live webinar groups reported a significant difference between pre- and posttraining abilities ( P < 0.05 for both groups). Attendees of the face-to-face presentation reported higher likelihoods of providing each of the individual tasks required to provide an effective, brief tobacco cessation intervention ( P < 0.05 for each task). CONCLUSION These data suggest that more value exists in face-to-face education than live webinars when personal and interactive skills are the focus of the activity. PMID:24407740
Suchanek Hudmon, Karen; Hoch, Matthew A; Vitale, Frank M; Wahl, Kimberly R; Corelli, Robin L; de Moor, Carl
Findings from telephone focus groups have not been compared previously to findings from face-to-face focus groups. We conducted four telephone focus groups and five face-to-face focus groups in which a single moderator used the same open-ended questions and discussion facilitation techniques. This comparison was part of a larger study to gain a better understanding of employment experiences after diagnosis of gynecologic cancer. Offering the telephone option made it easier to recruit women from rural areas and geographically distant cities. Interaction between participants occurred in both types of focus group. Content analysis revealed that similar elements of the employment experience after cancer diagnosis were described by telephone and face-to-face participants. Participants disclosed certain emotionally sensitive experiences only in the telephone focus groups. Telephone focus groups provide useful data and can reduce logistical barriers to research participation. Visual anonymity might help some participants feel more comfortable discussing certain personal issues.
Frazier, Linda M.; Miller, Virginia A.; Horbelt, Douglas V.; Delmore, James E.; Miller, Brigitte E.; Paschal, Angelia M.
The lecture is often posited as the prototypical "face-to-face" educational encounter, seen as embodying key features of the pre-networked academy. These are implicitly characterised as forms of boundedness or impermeability, in terms of both the physical and temporal context, and the ontological status of the participants and the nature of the…
Universities are increasingly using advanced video-conferencing environments to interact for teaching and research purposes at a distance and in situations that combine distant participants with those face-to-face. Those who use these technologies expect professional development support to do so but we do not yet have a comprehensive research…
This paper examines online versus face-to-face organizational structure and pedagogy in terms of education and the teaching and learning process. The author distinguishes several important terms related to distance/online/e-learning, virtual learning and brick-and-mortar learning interactions and concepts such as asynchronous and synchronous…
"Hybrid schools" are schools that combine "face-to-face" education in a specific place with online instruction. In this article, the authors describe school models which offer a vision for what deeply integrated technology can mean for children's education, for the way schools are structured, and for the promise of greater efficiency amid a…
The Department of Dental Medicine of Lutheran Medical Center has developed an asynchronous online curriculum consisting of prerecorded PowerPoint presentations with audio explanations. The focus of this study was to evaluate if the new asynchronous format satisfied the educational needs of the residents compared to traditional lecture (face-to-face) and synchronous (distance learning) formats. Lectures were delivered to 219 dental residents employing face-to-face and synchronous formats, as well as the new asynchronous format; 169 (77 percent) participated in the study. Outcomes were assessed with pretests, posttests, and individual lecture surveys. Results found the residents preferred face-to-face and asynchronous formats to the synchronous format in terms of effectiveness and clarity of presentations. This preference was directly related to the residents' perception of how well the technology worked in each format. The residents also rated the quality of student-instructor and student-student interactions in the synchronous and asynchronous formats significantly higher after taking the lecture series than they did before taking it. However, they rated the face-to-face format as significantly more conducive to student-instructor and student-student interaction. While the study found technology had a major impact on the efficacy of this curricular model, the results suggest that the asynchronous format can be an effective way to teach a postgraduate course. PMID:24882771
Kunin, Marc; Julliard, Kell N; Rodriguez, Tobias E
Parallel face-to-face arene–arene binding energies between benzene and multi-halo substituted aromatics and between tyrptophan and multi-halo substituted aromatics were calculated at the MP2(full)\\/6-311G?? level of theory. A correlation was investigated between the binding energy and either the quadrupole moment (?zz) or the sum of the Hammett substituent constant ?p (??p) of the substituted aromatic. For both benzene and tryptophan, an
Shana Beg; Kristine Waggoner; Yusuf Ahmad; Michelle Watt; Michael Lewis
The proceedings of the 11th National Space Symposium entitled 'Vision and Reality: FacetoFace' is presented. Technological areas discussed include the following sections: Vision for the future; Positioning for the future; Remote sensing, the emerging era; space opportunities, Competitive vision with acquisition reality; National security requirements in space; The world is into space; and The outlook for space. An appendice is also attached.
Parallel face-to-face arene-arene binding energies between benzene and multi-halo substituted aromatics and between tyrptophan and multi-halo substituted aromatics were calculated at the MP2(full)/6-311G ?? level of theory. A correlation was investigated between the binding energy and either the quadrupole moment ( ?zz) or the sum of the Hammett substituent constant ?p (? ?p) of the substituted aromatic. For both benzene and tryptophan, an excellent correlation was found between the calculated binding energy with multi-halo substituted aromatics and the sum of the ? ?p values of the substituted aromatics.
Beg, Shana; Waggoner, Kristine; Ahmad, Yusuf; Watt, Michelle; Lewis, Michael
Although the spectacular spread of wired and wireless communication technologies\\u000asuch as the Internet and mobile phone have been discussed extensively in the academic\\u000aliterature, knowledge of the interactions among face-to-face (F2F) and electronic\\u000acommunication modes and their implications for travel behavior is rather limited. The\\u000asame is true for knowledge about factors influencing the choice for these types of
Currently, most of integrated transformers are fabricated without magnetic core. In order to reduce the size and to improve their performances, we were interested in the study of integrated transformers based of thin ferrite films. Interleaved and FacetoFace structures were simulated using the Ansoft HFSS simulator over a wide range of frequency (up to 100MHz). A high frequency electrical model has been defined to determine the main characteristics of the transformer and particularly the interwinding capacitance and coupling factor between primary and secondary windings. The simulation results allowed us to determine the geometrical dimensions of these structures in order to optimize the magnetic coupling coefficient and to minimize inter winding capacitance.
Youssouf, K.; Kahlouche, F.; Youssouf, M.; Capraro, S.; Chatelon, J. P.; Siblini, A.; Rousseau, J. J.
...Culturally Significant Objects Imported for Exhibition Determinations: ``FacetoFace...Florence, and Renaissance Painting'' Exhibition SUMMARY: Notice is hereby given of...that the objects to be included in the exhibition ``FacetoFace: Flanders,...
We introduce a novel paradigm for studying the cognitive processes used by listeners within interactive settings. This paradigm places the talker and the listener in the same physical space, creating opportunities for investigations of attention and comprehension processes taking place during interactive discourse situations. An experiment was conducted to compare results from previous research using videotaped stimuli to those obtained within the live face-to-face task paradigm. A headworn apparatus is used to briefly display LEDs on the talker's face in four locations as the talker communicates with the participant. In addition to the primary task of comprehending speeches, participants make a secondary task light detection response. In the present experiment, the talker gave non-emotionally-expressive speeches that were used in past research with videotaped stimuli. Signal detection analysis was employed to determine which areas of the face received the greatest focus of attention. Results replicate previous findings using videotaped methods. PMID:21113354
Thompson, Laura A; Malloy, Daniel M; Cone, John M; Hendrickson, David L
This article discusses the learning process undertaken by language teachers in a cyber face-to-face teacher training program. Eight tertiary Chinese language teachers attended a 12-week training program conducted in an online synchronous learning environment characterized by multimedia-based, oral and visual interaction. The term "cyber…
Apart from studying students' interaction in Web-based environments in computer-supported collaborative learning (CSCL), it is essential to recognize the importance of the contextual setting in which learning takes place. This study examines the role of face-to-face encounters as contextual support in an international teacher education course…
Every quarter at California State University East Bay, a special event-planning course is offered in a hybrid format (face-to-face and online) and uses interactive Problem-Based Learning (PBL) activities designed to challenge and inspire intellectual growth. The PLB method is different in that students are not only receivers of knowledge but are…
There has been an increasing interest in the use of computer-mediated communication (CMC) in problem-based learning. One line of research has been to introduce synchronous, or simultaneous, communication attempting to create text-based digital real-time interaction. Compared with face-to-face (F2F) communication, CMC may be a poorer medium…
In this study the authors attempted to unravel the relational, dynamical, and historical nature of mother-infant communication during the first 6 months. Thirteen mothers and their infants were videotaped weekly from 4 to 24 weeks during face-to-faceinteractions. Three distinct patterns of mother-infant communication were identified: symmetrical,…
Physical activity is effective in preventing chronic diseases, increasing quality of life and promoting general health in older adults, but most older adults are not sufficiently active to gain those benefits. A novel and economically viable way to promote physical activity in older adults is through non-face-to-face interventions. These are conducted with reduced or no in-person interaction between intervention provider and program participants. The aim of this review was to summarize the scientific literature on non-face-to-face physical activity interventions targeting healthy, community dwelling older adults (? 50 years). A systematic search in six databases was conducted by combining multiple key words of the three main search categories "physical activity", "media" and "older adults". The search was restricted to English language articles published between 1st January 2000 and 31st May 2013. Reference lists of relevant articles were screened for additional publications. Seventeen articles describing sixteen non-face-to-face physical activity interventions were included in the review. All studies were conducted in developed countries, and eleven were randomized controlled trials. Sample size ranged from 31 to 2503 participants, and 13 studies included 60% or more women. Interventions were most frequently delivered via print materials and phone (n=11), compared to internet (n=3) and other media (n=2). Every intervention was theoretically framed with the Social Cognitive Theory (n=10) and the Transtheoretical Model of Behavior Change (n=6) applied mostly. Individual tailoring was reported in 15 studies. Physical activity levels were self-assessed in all studies. Fourteen studies reported significant increase in physical activity. Eight out of nine studies conducted post-intervention follow-up analysis found that physical activity was maintained over a longer time. In the six studies where intervention dose was assessed the results varied considerably. One study reported that 98% of the sample read the respective intervention newsletters, whereas another study found that only 4% of its participants visited the intervention website more than once. From this review, non-face-to-face physical activity interventions effectively promote physical activity in older adults. Future research should target diverse older adult populations in multiple regions while also exploring the potential of emerging technologies. PMID:24612748
Physical activity is effective in preventing chronic diseases, increasing quality of life and promoting general health in older adults, but most older adults are not sufficiently active to gain those benefits. A novel and economically viable way to promote physical activity in older adults is through non-face-to-face interventions. These are conducted with reduced or no in-person interaction between intervention provider and program participants. The aim of this review was to summarize the scientific literature on non-face-to-face physical activity interventions targeting healthy, community dwelling older adults (? 50 years). A systematic search in six databases was conducted by combining multiple key words of the three main search categories “physical activity”, “media” and “older adults”. The search was restricted to English language articles published between 1st January 2000 and 31st May 2013. Reference lists of relevant articles were screened for additional publications. Seventeen articles describing sixteen non-face-to-face physical activity interventions were included in the review. All studies were conducted in developed countries, and eleven were randomized controlled trials. Sample size ranged from 31 to 2503 participants, and 13 studies included 60% or more women. Interventions were most frequently delivered via print materials and phone (n?=?11), compared to internet (n?=?3) and other media (n?=?2). Every intervention was theoretically framed with the Social Cognitive Theory (n?=?10) and the Transtheoretical Model of Behavior Change (n?=?6) applied mostly. Individual tailoring was reported in 15 studies. Physical activity levels were self-assessed in all studies. Fourteen studies reported significant increase in physical activity. Eight out of nine studies conducted post-intervention follow-up analysis found that physical activity was maintained over a longer time. In the six studies where intervention dose was assessed the results varied considerably. One study reported that 98% of the sample read the respective intervention newsletters, whereas another study found that only 4% of its participants visited the intervention website more than once. From this review, non-face-to-face physical activity interventions effectively promote physical activity in older adults. Future research should target diverse older adult populations in multiple regions while also exploring the potential of emerging technologies.
This classroom research explores the probable consequences of a blended Teaching English to Young Learners (TEYLs) course comprised of Moodle applications and facetoface instruction in the English Language Teaching (ELT) context. Contrary to previous facetoface only procedure, the course was divided into two segments: traditional classroom…
This paper reports an empirical study comparing the role of discourse and knowledge representations (graphical evidence mapping) in face-to-face versus synchronous online collaborative learning. Prior work in face-to-face collaborative learning situations has shown that the features of representational notations can influence the focus of…
Suthers, Daniel D.; Hundhausen, Christopher D.; Girardeau, Laura E.
This study illustrates the convergence of two teaching and learning media, face-to-face and online, as reflective lecturers seek to address the limitations of a single medium. Innovative university lecturers at a large Western Australia university were interviewed about their use of online environments with face-to-face students. The interview…
American colleges and universities have an expanding role to play in nurturing political engagement as more youth attend college. Given low voter turnout among college students yet growing experimental evidence that face-to-face mobilization can boost turnout, the experiment reported in this article examined the impact of a face-to-face college…
This study examines profiles of online and face-to-face students in a single information science school: the University of Wisconsin-Milwaukee School of Information Studies. A questionnaire was administered to 76 students enrolled in online course sections and 72 students enrolled in face-to-face course sections. The questionnaire examined student…
Little has been published about Internet instruction compared to traditional classroom teaching in undergraduate natural resource science (NRS) education. This study hypothesized associations between teaching environments (face-to-face only (FF), Web only (WE), mixed mode (MI)); and teaching philosophy, practices, and perceived course outcomes. A questionnaire was sent to 142 faculty members with experience teaching in these environments in Western US. Sixty percent responded. Data were analyzed using factor analysis and multivariate statistics. Only statistically significant differences are presented. Most respondents were male (68%) 50-59 years old (80%) and tenured (74%). Overall, Web-based instruction was not seen as equivalent to facetoface instruction. Adoption of the Internet for teaching was beyond critical mass. Most faculty members ranked their ability to use the Internet as average (27%) or expert (22%). Faculty rarely perceived students' learning experience in a WE course as "better" than FF. Web-based courses were not usually required of majors in the offering department. Faculty age, gender and experience are significant variables in use of some teaching practices. Faculty members who used the Internet favored a constructivist teaching philosophy, while FF and MI instruction tended towards a behaviorist philosophy. Respondents' most frequent teaching practices addressed connections, collaboration, meaning making, and learner autonomy. Collaborative teaching strategies were seldom used in Web-based instruction relative to FF. Learning assessments focused on learner interactions, efforts (individual or groups), and recall. The latter assessment was used less on the Web. Respondents viewed effective teaching in all teaching environments as achieving competency and application of knowledge. Personal experience, resource availability, and feedback were the most important influences on teaching. Resource availability constrained Internet instruction most. Instructional goals emphasized broad understanding of natural resources, information technology competence and effective communication in all learning environments. There was doubt that Web instruction adequately achieved critical thinking objectives. Key results should be verified independent of self reports. Overall, Web-based instruction was not seen as equivalent to facetoface instruction, indicating a need to assure that Web-based instruction is used optimally.
Visual communication cues facilitate interpersonal communication. It is important that we look at faces to retrieve and subsequently process such cues. It is also important that we sometimes look away from faces as they increase cognitive load that may interfere with online processing. Indeed, when typically developing individuals hold face gaze it interferes with task completion. In this novel study we quantify face interference for the first time in Williams syndrome (WS) and Autism Spectrum Disorder (ASD). These disorders of development impact on cognition and social attention, but how do faces interfere with cognitive processing? Individuals developing typically as well as those with ASD (n = 19) and WS (n = 16) were recorded during a question and answer session that involved mathematics questions. In phase 1 gaze behaviour was not manipulated, but in phase 2 participants were required to maintain eye contact with the experimenter at all times. Looking at faces decreased task accuracy for individuals who were developing typically. Critically, the same pattern was seen in WS and ASD, whereby task performance decreased when participants were required to hold face gaze. The results show that looking at faces interferes with task performance in all groups. This finding requires the caveat that individuals with WS and ASD found it harder than individuals who were developing typically to maintain eye contact throughout the interaction. Individuals with ASD struggled to hold eye contact at all points of the interaction while those with WS found it especially difficult when thinking. PMID:22356183
Riby, Deborah M; Doherty-Sneddon, Gwyneth; Whittle, Lisa
The study was designed to test the relative effectiveness of a Navigator intervention delivered face-to-face or by telephone to urban Native American women. The effectiveness of the intervention was evaluated using a design that included a pretest, random assignment to face-to-face or telephone group, and posttest. The Social Cognitive Theory-based intervention was a tailored education program developed to address individual risk factors for breast cancer. At posttest, self-reported mammograms in the past year increased from 29% to 41.3% in the telephone group and from 34.4%: to 45.2% in the face-to-face group. There was no difference in change from pretest to posttest between the telephone and face-to-face groups. Navigators can be effective in increasing adherence to recommendations for screening mammography among urban American Indian women.
This study compared students enrolled in a foundations research methods course utilizing face-to-face instruction with students taking the course via ITV. Students receiving face-to-face instruction scored better on the mid-term, but there were no statistically significant differences on the scores of the final examination, the written paper, or the final course grade. No statistically significant differences were found on a
Teleconferencing as a setting for scientific peer review is an attractive option for funding agencies, given the substantial environmental and cost savings. Despite this, there is a paucity of published data validating teleconference-based peer review compared to the face-to-face process. Our aim was to conduct a retrospective analysis of scientific peer review data to investigate whether review setting has an effect on review process and outcome measures. We analyzed reviewer scoring data from a research program that had recently modified the review setting from face-to-face to a teleconference format with minimal changes to the overall review procedures. This analysis included approximately 1600 applications over a 4-year period: two years of face-to-face panel meetings compared to two years of teleconference meetings. The average overall scientific merit scores, score distribution, standard deviations and reviewer inter-rater reliability statistics were measured, as well as reviewer demographics and length of time discussing applications. The data indicate that few differences are evident between face-to-face and teleconference settings with regard to average overall scientific merit score, scoring distribution, standard deviation, reviewer demographics or inter-rater reliability. However, some difference was found in the discussion time. These findings suggest that most review outcome measures are unaffected by review setting, which would support the trend of using teleconference reviews rather than face-to-face meetings. However, further studies are needed to assess any correlations among discussion time, application funding and the productivity of funded research projects.
Gallo, Stephen A.; Carpenter, Afton S.; Glisson, Scott R.
Wikis, as one of the Web 2.0 social networking tools, have been increasingly integrated into second language (L2) instruction to promote collaborative writing. The current study examined and compared summary writing abilities between students learning by wiki-based collaboration and students learning by traditional face-to-face collaboration.…
Universities and even high schools are moving more and more to online instruction as a cost-effective way to reach more students with fewer resources. This naturally raises the question: Can online learning be effective? (The question is not "Is online learning effective?" because just like face-to-face instruction, online instruction includes a diverse array of techniques.) In this paper I compare online and flipped face-to-face versions of an introductory astronomy course. Both versions were designed around student-centered learning principles, but the specific implementation of these principles varied according to the strengths of each type of instruction. Normalized Hake gains on the Star Properties Concept Inventory (SPCI) were quite similar for both classes: 56% and 58% for the online and flipped face-to-face versions, respectively. The gains obtained by students with low pre-test scores were as good as the ones achieved by students with high pre-test scores.
This comparative study examined discourse and opportunities for interaction in two mathematics education methods classes, one face-to-face and one synchronous, online. Due to the content taught in the course, this study also sought to determine prospective mathematics teachers' understanding of variability and the role of discourse in each…
This study examines the effects of two types of e-tutoring interventions (text-based vs. face-to-face videoconferencing, TB vs. F2F) on the grammar performance and motivation of low-achieving students. The study investigates the patterns of interaction between tutors and students in both platforms, including the manner in which tutors and students…
Online course offerings have been growing at a rapid pace in post-secondary education. An ordered probit model is estimated to analyze the effects of online vs. face-to-face course format in achieving specific letter grades. An upper-division agricultural economics course taught over 9 years using both formats is used for the analysis. For a…
Based on my fieldwork with Burmese teachers in Thailand, I describe the drawbacks of using IRB-mandated written consent procedures in my cross-cultural collaborative ethnographic research on education. Drawing on theories of intersubjectivity (Mikhail Bakhtin), ethics (Emmanuel Levinas), and translation (Naoki Sakai), I describe face-to-face…
Since the advent of fully online delivery of college-level coursework, a number of issues has preoccupied administrators, educators, and researchers with regard to student learning outcomes or performance vis-a-vis face-to-face delivery. The present study does not seek to demonstrate or to discover which mode of delivery is "superior" or…
The abandonment of face-to-face voice conversations in favor of the use of electronic conversations in composition classes is an issue to be interrogated. In a recent push to "prepare students for the 21st century," teachers are asked to teach computer applications in the humanities--and composition teachers, who will teach writing in computer…
Over the past decade, online classes have become extensively utilized by higher education. Recent literature found, when focusing on upper level courses and four-year college students, that online classes are as effective as face-to-face classes in serving the curricular needs of students. This study sought to enrich research by examining…
Online discussions and transcriptions of face-to-face discussions by graduate students (14 online, 14 on campus) were analyzed. Technical support was not available 24 hours a day to online students who were predominantly women. Online discussions were more student-to-student, classroom discussions student-to-teacher. The analysis suggests how…
The training of raters for writing assessment through web-based programmes is emerging as an attractive and flexible alternative to the conventional method of face-to-face training sessions. Although some online training programmes have been developed, there is little published research on them. The current study aims to compare the effectiveness…
The issue of how people's discourse is affected by computer-supported collaborative work (CSCW) tools and shared workspaces was explored by examining collaboration on shared design tasks. Pairs of 28 less experienced and 28 more experienced engineering design students undertook a computer-assisted design task, either face-to-face (FtF) or…
Anderson, Tony; Sanford, Alison; Thomson, Avril; Ion, William
This paper focuses on the development of videogame-like applications in a 3D virtual environment as a complement to the face-to-face teaching and learning. With the changing role of teaching and learning and the increasing use of "blended learning," instructors are increasingly expected to explore new ways to attend to the needs of their students.…
Berns, Anke; Gonzalez-Pardo, Antonio; Camacho, David
Information Integration Theory (IIT) is concerned with how people combine information into an overall judgment. A method is hereby presented to perform Functional Measurement (FM) experiments, the methodological counterpart of IIT, on the Web. In a comparison of Web-based FM experiments, face-to-face experiments, and computer-based experiments in…
The experiences of students taking the same course by distance learning were compared when tutorial support was provided conventionally (using limited face-to-face sessions with some contact by telephone and email) or online (using a combination of computer-mediated conferencing and email). Study 1 was a quantitative survey using an adapted…
The experiences of students taking the same courses in the humanities by distance learning were compared when tutorial support was provided conventionally (using limited face-to-face sessions with some contact by telephone and email) or online (using a combination of computer-mediated conferencing and email). The Course Experience Questionnaire…
Education in an online setting is an increasingly popular method of instruction. Previous studies comparing college or high school student performance in online and face-to-face courses found, in most cases, similar achievement between conditions. However, research is lacking regarding middle school students' academic performance and attitudes…
This article describes a quasi-experimental comparison of two master's level social work classes delivering content on human behavior in the social environment. One class, delivered face-to-face, was largely synchronous. The other class, delivered using distance technologies, was more asynchronous than the first. The authors hypothesized that…
Two approaches to training for small/medium-sized enterprises were compared: a British distance learning program and an Irish program offering face-to-face training for micro-enterprises. Both used constructivist, collaborative, and reflective methods. Advantages and disadvantages of each approach were identified. (SK)
This paper reports and analyses data from a longitudinal qualitative research study which is investigating the changing teaching self-concept of university lecturers who combine online and face-to-face teaching. The first phase of this collective case study research has focused on the experiences of five 'early adopter' university lecturers during…
This article compares actual help-seeking frequencies across online and face-to-face learning environments. It also examines strategies enacted by nursing students when they faced academic difficulties, reasons for help-seeking avoidance, and the relationship between the frequency of asking questions and achievement. Participants were nursing…
Mahasneh, Randa A.; Sowan, Azizeh K.; Nassar, Yahya H.
This study compared student group work experiences in online (OL) versus face-to-face (f2f) sections of the same graduate course, over three years, to determine what factors influence student group work experiences and how do these factors play out in f2f versus OL environments. Surveys and student journals suggest that communication issues,…
Smith, Glenn Gordon; Sorensen, Chris; Gump, Andrew; Heindel, Allen J.; Caris, Mieke; Martinez, Christopher D.
This paper reports on an investigation into learning through discussions by undergraduate social work students. Second-year students studying psychology for social work experienced discussions began with face-to-face tutorials, and then continued for some time after online. This study used closed-ended questionnaires to investigate what students…
Ellis, Robert A.; Goodyear, Peter; O'Hara, Agi; Prosser, Michael
Since 1999, and as part of an Ameritech grant, the author has systematically investigated use of streaming media to enhance face-to-face classes. Technology invites experimentation but raises questions about such things as student acceptance, student use, academic performance, and what to do with class time when lectures are put online. Students…
With the increasing number of online courses within many higher education institutions, experienced instructors are facing the possibility of teaching online. These faculty members may face the task of converting their well-established face-to-face teaching strategies into an online environment. To better understand this transition, we analyzed…
Sugar, William; Martindale, Trey; Crawley, Frank E.
In order to examine current online course delivery systems, the authors created and conducted a survey that examined both face-to-face (FTF) and online education (OE) classes offered at 46 universities and some community colleges in the United States, as well as at some foreign universities. Students were asked whether they preferred FTF or OE…
Kishore, Masao; Tabrizi, M. H. Nassehzadeh; Ozan, Erol; Aziz, Shahnaz; Wuensch, Karl L.
Performance technologists have the opportunity to employ blended instruction, a combination of face-to-face and online teaching. Faced with the benefits of using the best of both of these forms of instruction in a single training program, performance technologists must make some thoughtful decisions to create a successful design for learning.…
This study compared face-to-face and videoconference private music lessons of one saxophone and two tuba students. One value of this study is the magnitude of the data analysis. More than 28,800 frames of digital video and verbatim scripts of all lessons were analyzed for time spent engaged in sequential patterns of instruction, performance, focus…
Enrollments in online programs are growing, increasing demand for online courses. The perception that teaching online takes more time than teaching face-to-face creates concerns related to faculty workload. To date, the research on teaching time does not provide a clear answer as to the accuracy of this perception. This study was designed to…
The trend in adoption since the 1960s has been away from secrecy and towards greater openness; contact through an intermediary, and direct contact by letter, is now widely accepted. More controversial is the challenge of face-to-face contact with birth parents, and social workers involved in the decision-making process find themselves having to…
This article examines face-to-face contact as a way in which children practise, imagine and constitute their closest relationships. Based on the findings of a qualitative school-based study, the article shows that children regard "seeing" as a family and relational practice that enables them to feel connected to and develop affinities with others.…
This study compared student performances in role-playing activities in both a face-to-face (FTF) environment and a virtual 3D environment, Second Life (SL). We found that students produced a similar amount of communication in the two environments, but the communication styles were different. In SL role-playing activities, students took more…
This article compares Global Assessment of Function (GAF) and Client Satisfaction Survey scores for clients receiving either face-to-face or online counselling. Clients were assessed by phone and then assigned to one of the two modalities. Analyses of variance were conducted with ? = 0.05, to examine differences between counselling modalities. No significant differences were found for degree of change in
Lawrence Murphy; Paul Parnass; Daniel L. Mitchell; Rebecca Hallett; Paula Cayley; Samantha Seagram
Disordered eating behavior is common in college women. Thus, it is important to develop programs to reduce eating disorder (ED) risk. Studies suggest that dissonance-based (DB) prevention programs successfully reduce ED risk factors; however, face-to-face DB groups lack anonymity and convenience. One way to address these barriers is to adapt DB programs for online use. Few studies have examined the feasibility of this delivery mode. This study compared the efficacy of an online DB program with a face-to-face DB program and an assessment-only condition. Undergraduate women (N = 333) recruited from a participant pool at a public university in the mid-Atlantic United States participated (n = 107 face-to-face DB, n = 112 online DB, n = 114 assessment-only). It was hypothesized that: (a) participants in the face-to-face and online DB conditions would report greater decreases in thin-ideal internalization, body dissatisfaction, and ED symptoms at post-testing relative to participants in the assessment-only control group, and (b) online and face-to-face programs would yield comparable results. Modified intent-to-treat analyses indicated that participants in both conditions manifested less body dissatisfaction at post-test compared with assessment-only participants; there were no significant differences in outcomes between the two modes of program delivery. These findings indicate that DB ED prevention programs can be successfully adapted for online use. Future studies should continue to refine online adaptations of such programs and examine their effects with samples that include older and younger women, and men. PMID:24456277
This paper describes use of social network analysis to examine student interaction patterns in a Grade 5/6 Knowledge Building class. The analysis included face-to-faceinteractions and interactions in the Knowledge Forum[R] Knowledge Building environment. It is argued that sociogram data are useful to reveal group processes; in sociological terms,…
The purpose of this study was to compare differences in emotional self-disclosure between young adult Internet users who prefer face-to-face therapy to those who prefer Internet therapy. A convenience sample of 328 was recruited from Facebook to complete an online survey. A total of 263 preferred face-to-face therapy (F2FT) while 65 preferred Internet therapy (IT). Significant differences were found with the F2FT group willing to disclose emotions of depression, jealously, anxiety, and fear to a therapist more frequently than the IT group. The majority reported a preference for F2FT over IT. Recommendations for future professional practice and research are included. PMID:19742368
Rogers, Vickie L; Griffin, Mary Quinn; Wykle, May L; Fitzpatrick, Joyce J
In large complex structures, with several major sound transmission paths and high levels of background noise, it can be a complex task to locate and rank the contribution of an individual sound transmission path. The two microphone acoustic intensity techniques are investigated as a tool for path identification. Laboratory tests indicate that, if the intensity transmitted through a particular section of the fuselage is measured in the presence and absence of flanking paths using the facetoface and side by side microphone arrangements, then no significant difference exists between the two measured intensities if the facetoface microphone arrangement is used. However, if the side by side arrangement is used, then considerable difference exists between the two measured intensities.
Purpose: To increase the number of high-risk and homeless youth who receive human immunodeficiency virus (HIV) test results and posttest counseling.Methods: Oral HIV testing and counseling were offered to high-risk and homeless youth at sites at which youth congregate throughout Portland, Oregon. Subjects were randomized to receive test results and posttest counseling either in a face-to-face manner or with the
Rachel C Tsu; Michael L Burm; Jennifer A Gilhooly; C. Wayne Sells
This session provides some discussions on blended course design, hands-on practices and offer practical tips for faculty who wish to explore the types of benefits from turning a face-to-face course into a more engaging blended (hybrid) course. Through this discussion, the participants will learn how to evaluate various factors in determining how to develop such a blended course, consider the
A low-cost, effective learning management system to support face-to-face teaching using standard Microsoft Office System software is described. This paper goes on to discuss the implementation, hosting, content creation and usage issues encountered during an 8-month trial that covered two full teaching semesters at Bond University. Bond University, based on the Gold Coast, is Australia’s first private university and specializes
We studied the dynamic behavior of laser-diode-pumped nonidentical thin-slice solid-state lasers, coupled facetoface, with orthogonally polarized emissions. When such an incoherent mutual optical coupling was introduced, the coupled lasers exhibited slow fluctuations of transverse-mode patterns, and isolated lasers exhibited stable transverse-mode patterns. When one laser exhibited nonorthogonal multi-transverse-mode operations without coupling, simultaneous random bursts of chaotic relaxation oscillations
Takayuki Ohtomo; Yoshihiko Miyasaka; Kenju Otsuka; Akane Okamoto; Jing-Yuan Ko
A field experiment was conducted to analyze the process and contents of group discussions. Groups solved a case study either orally or through an asynchronous computer-mediated communication system. Findings show that asynchronous groups had broader discussions and submitted more complete reports than their face-to-face counterparts. However, there was no difference in the ability to transfer information from the discussion to
The issue of how people's discourse is affected by computer-supported collaborative work (CSCW) tools and shared workspaces was explored by examining collaboration on shared design tasks. Pairs of 28 less experienced and 28 more experienced engineering design students undertook a computer-assisted design task, either face-to-face (FtF) or remotely. The CSCW medium provided views of interlocutors' faces and upper body plus
Tony Anderson; Alison Sanford; Avril Thomson; William Ion
This study compared face-to-face and videoconference private music lessons of one saxophone and two tuba students. One value of this study is the magnitude of the data analysis. More than 28,800 frames of digital video and verbatim scripts of all lessons were analyzed for time spent engaged in sequential patterns of instruction, performance, focus of attention, eye contact, and other
We compared psychiatrists' evaluations of Emergency Department (ED) mental health patients made face-to-face or by telemedicine. In a 39-month study, 73 patients presenting in the ED were enrolled after initial screening. Patients were interviewed by a psychiatrist either face-to-face in the ED or remotely by video. A second psychiatrist, acting as an observer, was in the room with the patient and independently completed the assessment. Based on the primary diagnosis of the interviewer, 48% of patients had a depressive disorder, 18% a substance use disorder, 14% a bipolar disorder, 11% a psychotic disorder, 6% an anxiety disorder and 4% other disorders. The raw agreement between the psychiatrists about disposition when both used face-to-face assessment was 84% and it was 86% when one used telemedicine. Using Cohen's kappa to evaluate agreement, there were no significant differences for disposition recommendation, strength of recommendation, diagnosis or the HCR-20 dangerousness scale. There was no significant difference for the intraclass correlation coefficients for the suicide scale. The results provide preliminary support for the safe use of telepsychiatry in the ED to determine the need for admission to inpatient care. PMID:24414395
Examines the development of a class at Brigham Young University (Utah) that blends distance and face-to-face students in a synchronous class. This case study focuses on how this blended learning environment was experienced by the distance and face-to-face students, as well as by the instructor. (MES)
Rogers, P. Clint; Graham, Charles R.; Rasmussen, Rus; Campbell, J. Olin; Ure, Donna M.
This study focused on students' conceptions of and approaches to learning through face-to-face and online discussions. The study setting was a course in which students (N = 110) worked in small teams and in which team discussions took place both face-to-face and online. The design of the study involved a combination of in-depth interviews and…
Ellis, Robert A.; Goodyear, Peter; Calvo, Rafael A.; Prosser, Michael
Providing patients with clear and concise information is central to modern medical practice. Patients diagnosed with skin cancer are traditionally told their result by face-to-face consultation in the outpatient clinic. Previous studies have shown poor patient satisfaction with the traditional outpatient consultation. The skin oncology service at Kingston Hospital uses two different methods to inform selected patients of their skin cancer diagnosis. Those diagnosed with thin melanoma (MM) or squamous cell carcinoma (<2 cm) (SCC) are informed by letter (with an accompanying information leaflet), or seen in outpatient clinic for a face-to-face consultation. However, it is unclear which of these methods patients prefer. We performed a retrospective postal questionnaire survey to elicit the views of patients that had been informed of their skin cancer by these two methods. Patients had been diagnosed with either MM or SCC between February 2005 and March 2006. Demographic details and patient satisfaction using five-point Likert scales were determined. Of the eligible 118 patients, 90 (76%) completed the questionnaire. Questionnaires from five respondents were incorrectly completed and excluded from further analysis. Of the final 85 patients, 41 (48%) were told their diagnosis via face-to-face consultation (clinic) and 44 (52%) by letter. The demographic profile of both groups was similar (P>0.05). Patients of both groups had a similar expectation of being told a skin cancer diagnosis (P>0.05). A high level of satisfaction was expressed for both methods of communication, with no difference between the groups (P>0.05). In the letter group, patients placed more value on convenience than preference to seeing a doctor (P<0.001). The option of contacting a support nurse was also cited as a reassuring feature. The findings of this study suggest disclosure of skin cancer diagnosis by letter has high satisfaction, for selected patients. Using this method of communication may ultimately lessen the burden on outpatient service. PMID:18485851
Karri, V; Bragg, T W H; Jones, A; Soldin, M; Misch, K
Objective: To compare the experiences of women with metastatic breast cancer (MBC) in computer-mediated and face-to-face support groups. Method: Interviews from 18 women with MBC, who were currently in computer-mediated support groups (CMSGs), were examined using interpretative phenomenological analysis. The CMSGs were in an asynchronous mailing list format; women communicated exclusively via email. All the women were also, or had previously been, in a face-to-face support group (FTFG). Results: CMSGs had both advantages and drawbacks, relative to face-to-face groups (FTFGs), for this population. Themes examined included convenience, level of support, intimacy, ease of expression, range of information, and dealing with debilitation and dying. CMSGs may provide a sense of control and a greater level of support. Intimacy may take longer to develop in a CMSG, but women may have more opportunities to get to know each other. CMSGs may be helpful while adjusting to a diagnosis of MBC, because women can receive support without being overwhelmed by physical evidence of disability in others or exposure to discussions about dying before they are ready. However, the absence of nonverbal cues in CMSGs also led to avoidance of topics related to death and dying when women were ready to face them. Agendas for discussion, the presence of a facilitator or more time in CMSGs may attenuate this problem. Significance of results: The findings were discussed in light of prevailing research and theories about computer-mediated communication. They have implications for designing CMSGs for this population. PMID:23768772
Alternative views of computer-mediated communication suggest that it is devoid of affective cues and interpersonal expression, or that the translation of affect into verbal cues facilitates relational communication. Little research has examined basic affective communication online, mirroring a dearth of empirical research identifying spontaneous affective verbal cues in face-to-faceinteraction. An experiment prompted participants to enact greater or lesser affinity
In the last ten years important breakthroughs in the understanding of the topology of complexity have been made in the framework of network science. Indeed it has been found that many networks belong to the universality classes called small-world networks or scale-free networks. Moreover it was found that the complex architecture of real world networks strongly affects the critical phenomena defined on these structures. Nevertheless the main focus of the research has been the characterization of single and static networks. Recently, temporal networks and interactingnetworks have attracted large interest. Indeed many networks are interacting or formed by a multilayer structure. Example of these networks are found in social networks where an individual might be at the same time part of different social networks, in economic and financial networks, in physiology or in infrastructure systems. Moreover, many networks are temporal, i.e. the links appear and disappear on the fast time scale. Examples of these networks are social networks of contacts such as face-to-faceinteractions or mobile-phone communication, the time-dependent correlations in the brain activity and etc. Understanding the evolution of temporal and multilayer networks and characterizing critical phenomena in these systems is crucial if we want to describe, predict and control the dynamics of complex system. In this thesis, we investigate several statistical mechanics models of temporal and interactingnetworks, to shed light on the dynamics of this new generation of complex networks. First, we investigate a model of temporal social networks aimed at characterizing human social interactions such as face-to-faceinteractions and phone-call communication. Indeed thanks to the availability of data on these interactions, we are now in the position to compare the proposed model to the real data finding good agreement. Second, we investigate the entropy of temporal networks and growing networks , to provide a new framework to quantify the information encoded in these networks and to answer a fundamental problem in network science: how complex are temporal and growing networks. Finally, we consider two examples of critical phenomena in interactingnetworks. In particular, on one side we investigate the percolation of interactingnetworks by introducing antagonistic interactions. On the other side, we investigate a model of political election based on the percolation of antagonistic networks. The aim of this research is to show how antagonistic interactions change the physics of critical phenomena on interactingnetworks. We believe that the work presented in these thesis offers the possibility to appreciate the large variability of problems that can be addressed in the new framework of temporal and interactingnetworks.
A hybrid course formally integrates the best pedagogical practices in a face-to-face class with the unique opportunities and flexibility inherent in an on-line class. I will describe a general astronomy course "The Universe in Ten Weeks" that was developed as a hybrid astronomy course at Cal Poly Pomona. Students interacted on a daily basis in discussions and observations. Class meetings were enormously productive and active. The instructor has daily feedback and came to class knowing the issues and questions that the students faced in their reading and on-line discussions. He knew before the face-to-face class meetings what conceptual challenges the students faced and what they wanted to research further. I will describe many of the techniques as well as the syllabus that made this class so successful for student learning.
We present a scalable experimental framework for gathering real-time data on face-to-face social interactions with tunable spatial and temporal resolution. We use active Radio Frequency Identification (RFID) devices that assess mutual proximity in a distributed fashion by exchanging low-power radio packets. We show results on the analysis of the dynamical networks of person-to-person interaction obtained in four high- resolution experiments carried out at different orders of magnitude in community size.
An open meeting of the Taxpayer Advocacy Panel Face-to-Face Service Methods Project Committee will be conducted. The Taxpayer Advocacy Panel is soliciting public comments, ideas, and suggestions on improving customer service at the Internal Revenue...
...DEPARTMENT OF HEALTH AND HUMAN SERVICES Centers for Medicare...Face-to-Face Requirements for Home Health Services; Policy Changes and Clarifications Related to Home Health AGENCY: Centers for Medicare &...
...face-to-face sale and distribution of tobacco products and the advertising, promotion, and marketing of tobacco products. FDA took this action...the Family Smoking Prevention and Tobacco Control Act (Pub. L. 111-31,...
We examine the role of face-to-face meetings in the context of technology-supported self-organizing distributed (or virtual teams), specifically free\\/libre open source software (FLOSS) development teams. Based on a qualitative inductive analysis of data from interviews and observations at FLOSS conferences, we identify a variety of settings in which developers meet face-to-face, and we point out the activities performed in these
Kevin Crowston; James Howison; Chengetai Masango; U. Yeliz Eseryel
A series of alkali salts of hydrogen bromanilic acid trihydrates (K(+), Rb(+) and Cs(+), potassium, rubidium and caesium 2,5-dibromo-4-hydroxy-3,6-dioxocyclohexa-1,4-dien-1-olate trihydrate), bromanilic acid tetrahydrate (Na(+), disodium 2,5-dibromo-3,6-dioxocyclohexa-1,4-diene-1,4-diolate tetrahydrate) and bromanilic acid dihydrates (K(+), Rb(+) and Cs(+), dipotasium, dirubidium and dicaesium 2,5-dibromo-3,6-dioxocyclohexa-1,4-diene-1,4-diolate dihydrate) were prepared and studied by single-crystal X-ray diffraction. Their crystal packings are dominated by quinoid ring stacking. The monoanionic quinoid rings pack face-to-face without offset and with short centroid separations (3.25-3.30 Å), while the dianionic rings form offset stacks (1.4-1.8 Å) with a larger centroid separation (3.8-4.1 Å). PMID:22267558
Accurately detecting emotional expression in women with primary breast cancer participating in support groups may be important for therapists and researchers. In 2 small studies (N = 20 and N = 16), the authors examined whether video coding, human text coding, and automated text analysis provided consistent estimates of the level of emotional expression. In Study 1, the authors compared coding from videotapes and text transcripts of face-to-face groups. In Study 2, the authors examined transcripts of online synchronous groups. The authors found that human text coding significantly overestimated Positive Affect and underestimated Defensive/Hostile Affect compared with video coding. They found correlations were low for Positive Affect but moderate for negative affect between Linguistic Inquiry Word Count (LIWC) and video coding. The implications of utilizing text-only detection of emotion are discussed. PMID:18540745
Background Internet-based cognitive behavioural therapy (iCBT) is an effective and acceptable treatment for depression, especially when it includes guidance, but its treatment adherence has not yet been systematically studied. We conducted a meta-analysis, comparing the adherence to guided iCBT with the adherence to individual face-to-face CBT. Methods Studies were selected from a database of trials that investigate treatment for adult depression (see www.evidencebasedpsychotherapies.org), updated to January 2013. We identified 24 studies describing 26 treatment conditions (14 face-to-face CBT, 12 guided iCBT), by means of these inclusion criteria: targeting depressed adults, no comorbid somatic disorder or substance abuse, community recruitment, published in the year 2000 or later. The main outcome measure was the percentage of completed sessions. We also coded the percentage of treatment completers (separately coding for 100% or at least 80% of treatment completed). Results We did not find studies that compared guided iCBT and face-to-face CBT in a single trial that met our inclusion criteria. Face-to-face CBT treatments ranged from 12 to 28 sessions, guided iCBT interventions consisted of 5 to 9 sessions. Participants in face-to-face CBT completed on average 83.9% of their treatment, which did not differ significantly from participants in guided iCBT (80.8%, P ?=? .59). The percentage of completers (total intervention) was significantly higher in face-to-face CBT (84.7%) than in guided iCBT (65.1%, P < .001), as was the percentage of completers of 80% or more of the intervention (face-to-face CBT: 85.2%, guided iCBT: 67.5%, P ?=? .003). Non-completers of face-to-face CBT completed on average 24.5% of their treatment, while non-completers of guided iCBT completed on average 42.1% of their treatment. Conclusion We did not find studies that compared guided iCBT and face-to-face CBT in a single trial. Adherence to guided iCBT appears to be adequate and could be equal to adherence to face-to-face CBT.
van Ballegooijen, Wouter; Cuijpers, Pim; van Straten, Annemieke; Karyotaki, Eirini; Andersson, Gerhard; Smit, Jan H.; Riper, Heleen
Graphene has attracted worldwide interest since its experimental discovery, but the preparation of large-area, continuous graphene film on SiO2/Si wafers, free from growth-related morphological defects or transfer-induced cracks and folds, remains a formidable challenge. Growth of graphene by chemical vapour deposition on Cu foils has emerged as a powerful technique owing to its compatibility with industrial-scale roll-to-roll technology. However, the polycrystalline nature and microscopic roughness of Cu foils means that such roll-to-roll transferred films are not devoid of cracks and folds. High-fidelity transfer or direct growth of high-quality graphene films on arbitrary substrates is needed to enable wide-ranging applications in photonics or electronics, which include devices such as optoelectronic modulators, transistors, on-chip biosensors and tunnelling barriers. The direct growth of graphene film on an insulating substrate, such as a SiO2/Si wafer, would be useful for this purpose, but current research efforts remain grounded at the proof-of-concept stage, where only discontinuous, nanometre-sized islands can be obtained. Here we develop a face-to-face transfer method for wafer-scale graphene films that is so far the only known way to accomplish both the growth and transfer steps on one wafer. This spontaneous transfer method relies on nascent gas bubbles and capillary bridges between the graphene film and the underlying substrate during etching of the metal catalyst, which is analogous to the method used by tree frogs to remain attached to submerged leaves. In contrast to the previous wet or dry transfer results, the face-to-face transfer does not have to be done by hand and is compatible with any size and shape of substrate; this approach also enjoys the benefit of a much reduced density of transfer defects compared with the conventional transfer method. Most importantly, the direct growth and spontaneous attachment of graphene on the underlying substrate is amenable to batch processing in a semiconductor production line, and thus will speed up the technological application of graphene. PMID:24336218
Graphene has attracted worldwide interest since its experimental discovery, but the preparation of large-area, continuous graphene film on SiO2/Si wafers, free from growth-related morphological defects or transfer-induced cracks and folds, remains a formidable challenge. Growth of graphene by chemical vapour deposition on Cu foils has emerged as a powerful technique owing to its compatibility with industrial-scale roll-to-roll technology. However, the polycrystalline nature and microscopic roughness of Cu foils means that such roll-to-roll transferred films are not devoid of cracks and folds. High-fidelity transfer or direct growth of high-quality graphene films on arbitrary substrates is needed to enable wide-ranging applications in photonics or electronics, which include devices such as optoelectronic modulators, transistors, on-chip biosensors and tunnelling barriers. The direct growth of graphene film on an insulating substrate, such as a SiO2/Si wafer, would be useful for this purpose, but current research efforts remain grounded at the proof-of-concept stage, where only discontinuous, nanometre-sized islands can be obtained. Here we develop a face-to-face transfer method for wafer-scale graphene films that is so far the only known way to accomplish both the growth and transfer steps on one wafer. This spontaneous transfer method relies on nascent gas bubbles and capillary bridges between the graphene film and the underlying substrate during etching of the metal catalyst, which is analogous to the method used by tree frogs to remain attached to submerged leaves. In contrast to the previous wet or dry transfer results, the face-to-face transfer does not have to be done by hand and is compatible with any size and shape of substrate; this approach also enjoys the benefit of a much reduced density of transfer defects compared with the conventional transfer method. Most importantly, the direct growth and spontaneous attachment of graphene on the underlying substrate is amenable to batch processing in a semiconductor production line, and thus will speed up the technological application of graphene.
We are investigating the use of face-to-face porphyrin (FTF) materials as potential oxygen reduction catalysts in fuel cells. The FTF materials were popularized by Anson and Collman, and have the interesting property that varying the spacing between the porphyrin rings changes the chemistry they catalyze from a two-electron reduction of oxygen to a four-electron reduction of oxygen. Our goal is to understand how changes in the structure of the FTF materials lead to either two-electron or four-electron reductions. This understand of the FTF catalysis is important because of the potential use of these materials as fuel cell electrocatalysts. Furthermore, the laccase family of enzymes, which has been proposed as an electrocatalytic enzyme in biofuel cell applications, also has family members that display either two-electron or four electron reduction of oxygen, and we believe that an understanding of the structure-function relationships in the FTF materials may lead to an understanding of the behavior of laccase and other enzymes. We will report the results of B3LYP density functional theory studies with implicit solvent models of the reduction of oxygen in several members of the cobalt FTF family.
Background: A pre-colonoscopy consultation in colorectal cancer (CRC) screening is necessary to assess a screenee's general health status and to explain benefits and risks of screening. The first option allows for personal attention, whereas a telephone consultation does not require travelling. We hypothesised that a telephone consultation would lead to higher response and participation in CRC screening compared with a face-to-face consultation. Methods: A total of 6600 persons (50–75 years) were 1?:?1 randomised for primary colonoscopy screening with a pre-colonoscopy consultation either face-to-face or by telephone. In both arms, we counted the number of invitees who attended a pre-colonoscopy consultation (response) and the number of those who subsequently attended colonoscopy (participation), relative to the number invited for screening. A questionnaire regarding satisfaction with the consultation and expected burden of the colonoscopy (scored on five-point rating scales) was sent to invitees. Besides, a questionnaire to assess the perceived burden of colonoscopy was sent to participants, 14 days after the procedure. Results: In all, 3302 invitees were allocated to the telephone group and 3298 to the face-to-face group, of which 794 (24%) attended a telephone consultation and 822 (25%) a face-to-face consultation (P=0.41). Subsequently, 674 (20%) participants in the telephone group and 752 (23%) in the face-to-face group attended colonoscopy (P=0.018). Invitees and responders in the telephone group expected the bowel preparation to be more painful than those in the face-to-face group while perceived burden scores for the full screening procedure were comparable. More subjects in the face-to-face group than in the telephone group were satisfied by the consultation in general: (99.8% vs 98.5%, P=0.014). Conclusion: Using a telephone rather than a face-to-face consultation in a population-based CRC colonoscopy screening programme leads to similar response rates but significantly lower colonoscopy participation.
Stoop, E M; de Wijkerslooth, T R; Bossuyt, P M; Stoker, J; Fockens, P; Kuipers, E J; Dekker, E; van Leerdam, M E
Webquests have been used for some time to research a variety of topics. According to Lacina (2007), a webquest is an inquiry-based technology activity designed by Bernie Dodge and Tom March in which information is usually drawn from the Internet, and is a powerful instructional exercise both for teachers and students.Webquests enhance personal and…
This experimental study offers empirical evidence of the effect of the computer-mediated environment on the linguistic output of low proficiency learners. The subjects were 32 female undergraduates with high and low proficiency in ESL. A within-subject repeated measures concurrent nested QUAN-qual (Creswell, 2003) mixed methods approach was used.…
Cognitive behavioural therapy (CBT) is increasingly used to address the emotional and interpersonal problems of people with ID. There is a limited but promising evidence base supporting this activity. However, these individuals face real and continuing challenges in their lives that have implications for their self and interpersonal perceptions.…
Jahoda, A.; Dagnan, D.; Kroese, B. Stenfert; Pert, C.; Trower, P.
Joint attention behaviors include initiating one's own and responding to another's bid for joint attention to an object, person, or topic. Joint attention abilities in autism are pervasively atypical, correlate with development of language and social abilities, and discriminate children with autism from other developmental disorders. Despite the importance of these behaviors, the neural correlates of joint attention in individuals with autism remain unclear. This paucity of data is likely due to the inherent challenge of acquiring data during a real-time social interaction. We used a novel experimental set-up in which participants engaged with an experimenter in an interactiveface-to-face joint attention game during fMRI data acquisition. Both initiating and responding to joint attention behaviors were examined as well as a solo attention (SA) control condition. Participants included adults with autism spectrum disorder (ASD) (n = 13), a mean age- and sex-matched neurotypical group (n = 14), and a separate group of neurotypical adults (n = 22). Significant differences were found between groups within social-cognitive brain regions, including dorsal medial prefrontal cortex (dMPFC) and right posterior superior temporal sulcus (pSTS), during the RJA as compared to SA conditions. Region-of-interest analyses revealed a lack of signal differentiation between joint attention and control conditions within left pSTS and dMPFC in individuals with ASD. Within the pSTS, this lack of differentiation was characterized by reduced activation during joint attention and relative hyper-activation during SA. These findings suggest a possible failure of developmental neural specialization within the STS and dMPFC to joint attention in ASD. PMID:22505330
Redcay, Elizabeth; Dodell-Feder, David; Mavros, Penelope L; Kleiner, Mario; Pearrow, Mark J; Triantafyllou, Christina; Gabrieli, John D; Saxe, Rebecca
The purpose of this study was to investigate whether differences exist with regard to music achievement, music self-concept, or student course satisfaction among students enrolled in four different sections of an undergraduate music appreciation course taught from chronological or sociocultural approaches in online or face-to-face formats.…
Many studies have compared traditional face-to-face courses to online or distance education courses. The purpose of this study was to examine academic performance, perceptions, and experiences of participants enrolled in different academic learning environments. Pre and Post Content Knowledge Tests and a student evaluation were used to measure…
This is an exploratory paper that uses the construct of connectivity to examine the nature of effective language teaching and learning in both face-to-face and online learning environments. Broader in scope than Siemens' notion of connectivism, the term connectivity accommodates both transmission approaches to teaching and learning and social…
Embryology is integrated into the Clinically Oriented Anatomy course at the Texas Tech University Health Sciences Center School of Medicine. Before 2008, the same instructor presented embryology in 13 face-to-face lectures distributed by organ systems throughout the course. For the 2008 and 2009 offerings of the course, a hybrid embryology…
Beale, Elmus G.; Tarwater, Patrick M.; Lee, Vaughan H.
Studies examining the comparative efficacy of face-to-face and computer assisted library instruction were reviewed. Differences in study methodology and lack of quality made meta-analysis impossible; however, the two methods appear to be equally effective for teaching basic library skills. More research needs to be done to confirm this finding.
This paper reports a phenomenographic investigation into students' experiences of learning through discussion--both online and facetoface (F2F). The study context was a second-year undergraduate course in psychology for social work in which the teacher had designed discussion tasks to begin in F2F mode and to continue online. A combination of…
Ellis, Robert A.; Goodyear, P.; Prosser, M.; O'Hara, A.
Two projects attempted to assess and meet small and medium-sized enterprises' training needs. Britain's Learning support for Small Businesses delivery methods included paper, CD-ROM, and the Internet. The University of Limerick, Ireland, offered face-to-face learning for microenterprises. (SK)
This paper reports on research investigating student experiences of learning through face-to-face and online discussions in a political science course in a large Australian university. Using methodologies from relational research into university student learning, the study investigates associations between key aspects of student learning focusing…
Instructional content was presented differently in two introductory special education course sections. In a face-to-face (f2f) section, the instructor met with students on regularly scheduled days and times and presented content in person. In the other section, content was presented using enhanced podcasts, consisting of the instructor narrating…
Thompson, James R.; Klass, Patricia H.; Fulk, Barbara M.
The objective of this study was to assess if online teaching delivery produces comparable student test performance as the traditional face-to-face approach irrespective of academic aptitude. This study involves a quasi-experimental comparison of student performance in an undergraduate health science statistics course partitioned in two ways. The first partition involves one group of students taught with a traditional face-to-face classroom approach and the other through a completely online instructional approach. The second partition of the subjects categorized the academic aptitude of the students into groups of higher and lower academically performing based on their assignment grades during the course. Controls that were placed on the study to reduce the possibility of confounding variables were: the same instructor taught both groups covering the same subject information, using the same assessment methods and delivered over the same period of time. The results of this study indicate that online teaching delivery is as effective as a traditional face-to-face approach in terms of producing comparable student test performance but only if the student is academically higher performing. For academically lower performing students, the online delivery method produced significantly poorer student test results compared to those lower performing students taught in a traditional face-to-face environment. PMID:23238874
This study is a comparative analysis of the impact of traditional face-to-face training contrasted with a blended learning approach, as it relates to improving skills, knowledge and attitudes for enhancing practices for achieving improved employment outcomes for individuals with disabilities. The study included two intervention groups: one…
BACKGROUND: Education campaigns seeking to raise awareness of human papillomavirus (HPV) and promoting HPV vaccination depend on accurate surveys of public awareness and knowledge of HPV and related sexual behavior. However, the most recent population-based studies have relied largely on computer-assisted telephone interviews (CATI) as opposed to facetoface interviews (FTFI). It is currently unknown how these survey modes
Anthony Smith; Anthony Lyons; Marian Pitts; Samantha Croy; Richard Ryall; Suzanne Garland; Mee Lian Wong; Eng Hseon Tay
Online college classes are being offered at a rate that far exceeds the growth of overall higher education classes. However, much can still be learned about how to create a better online classroom environment by determining why a large percentage of students continue to prefer face-to-face classes. One factor among many that may have an influence…
With increased use of technology in qualitative research, it is important to understand unintended, unanticipated, and unobvious consequences to the data. Using a side-by-side comparison of face-to-face, telephone, and Internet with video focus groups, we examined the yield differences of focus group venue (medium) to the data (message) rendered…
Problem-based learning (PBL) is an instructional strategy that is poised for widespread application in the current, growing, on-line digital learning environment. While enjoying a track record as a defensible strategy in face-to-face learning settings, the research evidence is not clear regarding PBL in on-line environments. A review of the…
We asked the same 60 questions using DRS (digital reference services) in Japanese public libraries, face-to-face reference services and Q & A (question and answer) sites. It was found that: (1) The correct answer ratio of DRS is higher than that of Q & A sites; (2) DRS takes longer to provide answers as compared to Q & A sites; and (3) The correct…
Most face-to-faceinteractionnetworks are structured as predicted by Granovetter's dasiastrength of weak tiespsila theory. This paper seeks to verify whether friendship relation in social networking websites is structured similarly as in face-to-face social networks. This is accomplished by examining the most important consequences of the theory in four smaller educational online social networks. It was found that all of
A control valve that can throttle high-pressure cryogenic fluid embodies several design features that distinguish it over conventional valves designed for similar applications. Field and design engineers worked together to create a valve that would simplify installation, trim changes, and maintenance, thus reducing overall cost. The seals and plug stem packing were designed to perform optimally in cryogenic temperature ranges. Unlike conventional high-pressure cryogenic valves, the trim size can be changed independent of the body. The design feature that provides flexibility for changing the trim is a split body. The body is divided into an upper and a lower section with the seat ring sandwiched in between. In order to maintain the plug stem packing at an acceptable sealing temperature during cryogenic service, heat-exchanging fins were added to the upper body section. The body is made of stainless steel. The seat ring is made of a nickel-based alloy having a coefficient of thermal expansion less than that of the body material. Consequently, when the interior of the valve is cooled cryogenically, the body surrounding the seat ring contracts more than the seat ring. This feature prevents external leakage at the body-seat joint. The seat ring has been machined to have small, raised-face sealing surfaces on both sides of the seal groove. These sealing surfaces concentrate the body bolt load over a small area, thereby preventing external leakage. The design of the body bolt circle is different from that of conventional highpressure control valves. Half of the bolts clamp the split body together from the top, and half from the bottom side. This bolt-circle design allows a short, clean flow path, which minimizes frictional flow losses. This bolt-circle design also makes it possible to shorten the face-toface length of the valve, which is 25.5 in. (65 cm). In contrast, a conventional, high-pressure control valve face-to-face dimension may be greater than 40 in. (>1 m) long.
Background Nosocomial infections place a substantial burden on health care systems and represent one of the major issues in current public health, requiring notable efforts for its prevention. Understanding the dynamics of infection transmission in a hospital setting is essential for tailoring interventions and predicting the spread among individuals. Mathematical models need to be informed with accurate data on contacts among individuals. Methods and Findings We used wearable active Radio-Frequency Identification Devices (RFID) to detect face-to-face contacts among individuals with a spatial resolution of about 1.5 meters, and a time resolution of 20 seconds. The study was conducted in a general pediatrics hospital ward, during a one-week period, and included 119 participants, with 51 health care workers, 37 patients, and 31 caregivers. Nearly 16,000 contacts were recorded during the study period, with a median of approximately 20 contacts per participants per day. Overall, 25% of the contacts involved a ward assistant, 23% a nurse, 22% a patient, 22% a caregiver, and 8% a physician. The majority of contacts were of brief duration, but long and frequent contacts especially between patients and caregivers were also found. In the setting under study, caregivers do not represent a significant potential for infection spread to a large number of individuals, as their interactions mainly involve the corresponding patient. Nurses would deserve priority in prevention strategies due to their central role in the potential propagation paths of infections. Conclusions Our study shows the feasibility of accurate and reproducible measures of the pattern of contacts in a hospital setting. The obtained results are particularly useful for the study of the spread of respiratory infections, for monitoring critical patterns, and for setting up tailored prevention strategies. Proximity-sensing technology should be considered as a valuable tool for measuring such patterns and evaluating nosocomial prevention strategies in specific settings.
Isella, Lorenzo; Romano, Mariateresa; Barrat, Alain; Cattuto, Ciro; Colizza, Vittoria; Van den Broeck, Wouter; Gesualdo, Francesco; Pandolfi, Elisabetta; Rava, Lucilla; Rizzo, Caterina; Tozzi, Alberto Eugenio
This paper presents a location-aware educational game for the iPhone\\/iPod Touch platform. The game, KnowledgeWar, is a quiz game where students can challenge each other in face-to-face or remote knowledge battles. The game contains a game lobby where players can see all who are connected, and the physical distance to them. The paper describes our experiences from developing KnowledgeWar and
This article presents research on students' experiences of learning through a blend of face-to-face and online discussion. The participants in our study were students enrolled in a foreign policy course at a major Australian university. Students' conceptions of learning through discussion, and their approaches to both face-to-face and online…
Bliuc, Ana-Maria; Ellis, Robert A.; Goodyear, Peter; Piggott, Leanne
This study tests a number of predictions about the effectiveness of four different strategies for teaching three to four year old children how to master a difficult construction task. These strategies were derived from previous studies of mother-child and experimenter-child interactions in an assisted learning situation. One strategy the 'contingent approach' was based primarily on theoretical considerations and when used
Human mothers interact emotionally with their newborns through exaggerated facial expressions, speech, mutual gaze, and body contact, a capacity that has long been considered uniquely human [1-4]. Current developmental psychological theories propose that this pattern of mother-infant exchange promotes the regulation of infant emotions [4-6] and serves as a precursor of more complex forms of social exchange including perspective taking and empathy. Here we report that in rhesus macaques, mother-infant pairs also communicate intersubjectively via complex forms of emotional exchanges including exaggerated lipsmacking, sustained mutual gaze, mouth-mouth contacts, and neonatal imitation. Infant macaques solicit their mother's affiliative responses and actively communicate to her. However, this form of communication disappears within the infant's first month of life. Our data challenge the view that the mother-infant communicative system functions in order to sustain proximity and that infants are simply passive recipients in such interaction. Thus, emotional communication between mother and infant is not uniquely human. Instead, we can trace back to macaques the evolutionary foundation of those behaviors that are crucial for the establishment of a functional capacity to socially exchange with others. PMID:19818617
Ferrari, Pier Francesco; Paukner, Annika; Ionica, Consuel; Suomi, Stephen J
The present study compared the impact of facetoface teaching with a short online game informed learning activity on health participants' knowledge about, and confidence in, managing aggressive situations. Both forms of teaching resulted in a significant increase in participants' knowledge and confidence. Facetoface training led to significantly greater increases in knowledge but was equivalent in terms of confidence. Both forms of teaching were rated positively, but facetoface teaching received significantly higher ratings than the online activity. The study suggests that short online game informed learning activities may offer an effective alternative for health professional training where facetoface training is not possible. Further research is needed on the longer term impact of both types of training on practice. PMID:23184436
Increased access to therapy for body dissatisfaction and disordered eating is required. This pilot study compared a group intervention delivered face-to-face or synchronously over the Internet. Women with body dissatisfaction and disordered eating were randomly assigned to a face-to-face (N = 19) or Internet (N = 21) group. Body dissatisfaction, disordered eating, and psychological variables were assessed at baseline, post-intervention,
Currently, most breast cancer (BC) patients receive face-to-face genetic counseling (DNA-intake) prior to BRCA-mutation testing, with generic information regarding hereditary BC and BRCA-mutation testing. This prospective study evaluated a novel format: replacing the intake consultation with telephone, written and digital information sent home, and face-to-face contact following BRCA-mutation testing (DNA-direct). From August 2011 to February 2012, 161 of 233 eligible BC patients referred to our Human Genetics department chose between DNA-direct (intervention) or DNA-intake (control). Exclusion criteria were psychological problems (n = 33), difficulty with Dutch text (n = 5), known BRCA-family (n = 3), non-BRCA-referral (n = 1). 30 declined genetic counseling or study participation. Participants received questionnaires including satisfaction and psychological distress. 59 % chose DNA-direct (p = 0.03), of whom 90 % were satisfied and would choose DNA-direct again (including 6/8 BRCA-mutation carriers); although 27 % hesitated to recommend DNA-direct to other patients. General distress (GHQ-12, p = 0.001) and heredity-specific distress (IES, p = 0.02) scored lower in DNA-direct than DNA-intake, both at baseline and follow-up 2 weeks after BRCA-result disclosure; all scores remained below clinical relevance. DNA-direct participants reported higher website use (53 vs. 32 %, p = 0.01), more referrer information about personal consequences (41 vs. 20 %, p = 0.004) and lower decisional conflict (median 20 [0-88] vs. 25 [0-50], p = 0.01). Processing time in DNA-direct was reduced by 1 month. Mutation detection rate was 8 % in both groups. All BRCA-mutation carriers fulfilled current testing criteria. In conclusion, more BC patients preferred DNA-direct over intake consultation prior to BRCA-mutation testing, the majority being strongly to moderately satisfied with the procedure followed, without increased distress. PMID:24068317
Sie, Aisha S; van Zelst-Stams, Wendy A G; Spruijt, Liesbeth; Mensenkamp, Arjen R; Ligtenberg, Marjolijn J L; Brunner, Han G; Prins, Judith B; Hoogerbrugge, Nicoline
Over evolutionary time, humans have developed a selective sensitivity to features in the human face that convey information\\u000a on sex, age, emotions, and intentions. This ability might not only be applied to our conspecifics nowadays, but also to other\\u000a living objects (i.e., animals) and even to artificial structures, such as cars. To investigate this possibility, we asked\\u000a people to report
Sonja Windhager; Dennis E. Slice; Katrin Schaefer; Elisabeth Oberzaucher; Truls Thorstensen; Karl Grammer
Background Information about web-based education outcomes in comparison with a face-to-face format can help researchers and tutors prepare and deliver future web-based or face-to-face courses more efficiently. The aim of this study was to compare the effectiveness of web-based and face-to-face continuing education methods in improving nurses' knowledge about AIDS. Methods A quasi-experimental method was used with a pre-test and post-test design. In this study 140 nurses with BSc degrees were chosen through a random sampling method and divided into a web-based and a face-to-face group by random allocation. For the former group the intervention consisted of a web-based course on AIDS; the latter received a 3-hour lecture course on the same subject. At the beginning and end of the course in both groups, the nurses' knowledge was measured by a questionnaire. Pre- and post-test scores were compared within and between the groups. Results The results show that there was no significant difference between the groups in either the pre-test (t(138) = -1.7, p = 0.096) nor the post-test (t(138) = -1.4, p = 0.163) scores in the knowledge test. However, there was a significant difference in the pre-test and post-test scores within each group (web-based, t(69) = 26, p < .001; face-to-face, t(69) = 24.3, p < .001). Conclusion The web-based method seems to be as effective as the face-to-face method in the continuing education of nurses. Therefore, the web-based method is recommended, as complementary to the face-to-face method, for designing and delivering some topics of continuing education programs for nurses.
Self-seeded passive optical networks (PONs) are currently attracting extensive research interest. In this paper, a novel self-seeded PON transmitter is, for the first time, proposed and experimentally demonstrated, which incorporates two face-to-face-positioned reflective semiconductor optical amplifiers (RSOAs) operating at their gain saturation regions: one RSOA directly driven by an upstream electrical signal and the other RSOA biased at a fixed current. Detailed experimental explorations are undertaken of the dynamic performance characteristics of the proposed transmitter. It is shown that, in comparison with previously reported self-seeded transmitters each employing a reflective mirror and a single electrical signal-driven RSOA, the proposed transmitter has a number of salient advantages including, considerably narrowed optical signal spectra, up to 16dB reduction in RINs of intensity-modulated optical signals, and residual intensity modulation crosstalk suppression as high as 10.7dB. The aforementioned features enable experimental demonstrations of real-time self-seeded 10Gb/s optical OFDM (OOFDM) transmitters. In particular, by making use of two low-cost RSOAs having their 3-dB modulation bandwidths as small as 1.125GHz, 10Gb/s over 25km adaptive OOFDM transmissions with power penalties of 0.6dB are experimentally achieved in the simple self-seeded IMDD PON systems. PMID:24921316
Deng, M L; Ling, Y; Chen, X F; Giddings, R P; Hong, Y H; Yi, X W; Qiu, K; Tang, J M
Drawing from theory and research on perceived stigma (Pryor, Reeder, Yeadon, & Hesson-McInnis, 2004), attentional processes (Rinck & Becker, 2006), working memory (Baddeley & Hitch, 1974), and regulatory resources (Muraven & Baumeister, 2000), the authors examined discrimination against facially stigmatized applicants and the processes involved. In Study 1, 171 participants viewed a computer-mediated interview of an applicant who was facially stigmatized or not and who either did or did not acknowledge the stigma. The authors recorded participants' (a) time spent looking at the stigma (using eye tracker technology), (b) ratings of the applicant, (c) memory recall about the applicant, and (d) self-regulatory depletion. Results revealed that the participants with facially stigmatized applicants attended more to the cheek (i.e., where the stigma was placed), which led participants to recall fewer interview facts, which in turn led to lower applicant ratings. In addition, the participants with the stigmatized (vs. nonstigmatized) applicant depleted more regulatory resources. In Study 2, 38 managers conducted face-to-face interviews with either a facially stigmatized or nonstigmatized applicant, and then rated the applicant. Results revealed that managers who interviewed a facially stigmatized applicant (vs. a nonstigmatized applicant) rated the applicant lower, recalled less information about the interview, and depleted more self-regulatory resources. PMID:22004221
Background Education campaigns seeking to raise awareness of human papillomavirus (HPV) and promoting HPV vaccination depend on accurate surveys of public awareness and knowledge of HPV and related sexual behavior. However, the most recent population-based studies have relied largely on computer-assisted telephone interviews (CATI) as opposed to facetoface interviews (FTFI). It is currently unknown how these survey modes differ, and in particular whether they attract similar demographics and therefore lead to similar overall findings. Methods A comprehensive survey of HPV awareness and knowledge, including sexual behavior, was conducted among 3,045 Singaporean men and women, half of whom participated via CATI, the other half via FTFI. Results Overall levels of awareness and knowledge of HPV differed between CATI and FTFI, attributable in part to demographic variations between these survey modes. Although disclosure of sexual behavior was greater when using CATI, few differences between survey modes were found in the actual information disclosed. Conclusion Although CATI is a cheaper, faster alternative to FTFI and people appear more willing to provide information about sexual behavior when surveyed using CATI, thorough assessments of HPV awareness and knowledge depend on multiple survey modes.
Improved epitaxial graphene films have been widely reported when the sublimation rate of Si is reduced by ambient Ar gas, vapor phase silane, or confined Si vapor. We describe graphene growth on (0001) 6H-SiC samples annealed ``face-to-face'' ; in our modified method the separation is limited only by the flatness of the surfaces. After annealing in 100 kPa Ar gas at 2000 ^oC for 300 s, atomic force microscopy (AFM) and electrostatic force microscopy (EFM) show graphene coverage is typically between one and a few layers. Samples without prior hydrogen etching undergo surface reconstruction in the graphitization process, resulting in atomically flat terraces with step bunching. Estimates of the sequestered carbon in the form of graphene are compared to calculated levels due to sublimation and diffusion rates where the sublimated gas is dominated by Si atoms below 2100 ^oC. The 2000 ^oC samples are contrasted against samples processed between 1700 ^oC and 1900 ^oC and transport results on large-scale graphene devices are presented.[4pt]  X.Z Yu, C.G. Hwang, C.M. Jozwiak, A. Kohl, A.K. Schmid and A. Lanzara, New synthesis method for the growth of epitaxial graphene, Journal of Electron Spectroscopy and Related Phenomena 184 (2011) 100-106.
Elmquist, Randolph E.; Real, Mariano; Bush, Brian G.; Shen, Tian; Stiles, Mark D.; Lass, Eric A.
Objective Most children with autism rely on schools as their primary source of intervention, yet research has suggested that teachers rarely use evidence-based practices. To address the need for improved educational outcomes, a previously tested consultation intervention called the Collaborative Model for Promoting Competence and Success (COMPASS; Ruble, Dalrymple, & McGrew, 2010; Ruble, Dalrymple, & McGrew, 2012) was evaluated in a 2nd randomized controlled trial, with the addition of a web-based group. Method Forty-nine teacher–child dyads were randomized into 1 of 3 groups: (1) a placebo control (PBO) group, (2) COMPASS followed by face-to-face (FF) coaching sessions, and (3) COMPASS followed by web-based (WEB) coaching sessions. Three individualized goals (social, communication, and independence skills) were selected for intervention for each child. The primary outcome of independent ratings of child goal attainment and several process measures (e.g., consultant and teacher fidelity) were evaluated. Results Using an intent-to-treat approach, findings replicated earlier results with a very large effect size (d = 1.41) for the FF group and a large effect size (d = 1.12) for the WEB group relative to the PBO group. There were no differences in overall change across goal domains between the FF and WEB groups, suggesting the efficacy of videoconferencing technology. Conclusions COMPASS is effective and results in improved educational outcomes for young children with autism. Videoconferencing technology, as a scalable tool, has promise for facilitating access to autism specialists and bridging the research-to-practice gap.
Ruble, Lisa A.; McGrew, John H.; Toland, Michael D.; Dalrymple, Nancy J.; Jung, Lee Ann
Background Exercise is an effective intervention for the prevention of falls; however, some forms of exercises have been shown to be more effective than others. There is a need to identify effective and efficient methods for training health professionals in exercise prescription for falls prevention. Objective The objective of our study was to compare two approaches for training clinicians in prescribing exercise to prevent falls. Methods This study was a head-to-head randomized trial design. Participants were physiotherapists, occupational therapists, nurses, and exercise physiologists working in Victoria, Australia. Participants randomly assigned to one group received face-to-face traditional education using a 1-day seminar format with additional video and written support material. The other participants received Web-based delivery of the equivalent educational material over a 4-week period with remote tutor facilitation. Outcomes were measured across levels 1 to 3 of Kirkpatrick’s hierarchy of educational outcomes, including attendance, adherence, satisfaction, knowledge, and self-reported change in practice. Results Of the 166 participants initially recruited, there was gradual attrition from randomization to participation in the trial (n = 67 Web-based, n = 68 face-to-face), to completion of the educational content (n = 44 Web-based, n = 50 face-to-face), to completion of the posteducation examinations (n = 43 Web-based, n = 49 face-to-face). Participant satisfaction was not significantly different between the intervention groups: mean (SD) satisfaction with content and relevance of course material was 25.73 (5.14) in the Web-based and 26.11 (5.41) in the face-to-face group; linear regression P = .75; and mean (SD) satisfaction with course facilitation and support was 11.61 (2.00) in the Web-based and 12.08 (1.54) in the face-to-face group; linear regression P = .25. Knowledge test results were comparable between the Web-based and face-to-face groups: median (interquartile range [IQR]) for the Web-based group was 90.00 (70.89–90.67) and for the face-to-face group was 80.56 (70.67–90.00); rank sum P = .07. The median (IQR) scores for the exercise assignment were also comparable: Web-based, 78.6 (68.5–85.1), and face-to-face, 78.6 (70.8–86.9); rank sum P = .61. No significant difference was identified in Kirkpatrick’s hierarchy domain change in practice: mean (SD) Web-based, 21.75 (4.40), and face-to-face, 21.88 (3.24); linear regression P = .89. Conclusion Web-based and face-to-face approaches to the delivery of education to clinicians on the subject of exercise prescription for falls prevention produced equivalent results in all of the outcome domains. Practical considerations should arguably drive choice of delivery method, which may favor Web-based provision for its ability to overcome access issues for health professionals in regional and remote settings. Trial Registration Australian New Zealand Clinical Trials Registry number: ACTRN12610000135011; http://www.anzctr.org.au/ACTRN12610000135011.aspx (Archived by WebCite at http://www.webcitation.org/63MicDjPV)
Haas, Romi; Keating, Jennifer L; Molloy, Elizabeth; Jolly, Brian; Sims, Jane; Morgan, Prue; Haines, Terry
This paper is arranged PIE data in order to provide data sheet for evaluation of core distortion. In this paper, there are two kinds of PIE data; one is facetoface distance data of the spacer pad part of lower guide tubes of control rod. The other is th...
This study uses a quasi-experimental design to assess differences in student performance and satisfaction across online and face-to-face (F2F) classroom settings. Data were collected from 368 students enrolled in three online and three F2F sections of an introductory-level sociology course. The instructor, course materials, and assessments were…
A relatively quick, face-to-face, adaptive working memory training intervention was assessed in 5-to 8-year-old typically developing children, randomly allocated to a 6-week intervention condition, or an active control condition. All children received 18 sessions of 10?minutes, three times/week for 6?weeks. Assessments of six working memory…
This article is based on the premise that face-to-face training can be augmented with cloud-based technology tools, to potentially extend viable training supports as higher education staff and faculty implement new content/skills in their jobs and classrooms. There are significant benefits to harnessing cloud-based tools that can facilitate both…
The researchers, a librarian and a faculty member, collaborated to investigate the effectiveness of delivery methods in information literacy instruction. The authors conducted a field experiment to explore how face-to-face, online, and blended learning instructional formats influenced students' retention of information literacy skills. Results are…
This study examined the final grade and satisfaction level differences among students taking specific courses using three different methods: face-to-face in class, via satellite broadcasting at remote sites, and via live video-streaming at home or at work. In each case, the same course was taught by the same instructor in all three delivery…
The researcher examined the effects of online (OL) and face-to-face (FTF) course modality choice, as a motivational component, on students. self-selection of courses. A naturally occurring control and treatment group comparison design was employed. The participants were 435 college students (200 OL and 235 FTF) who attended an accredited private…
This paper considers the influence of e-tuition using an asynchronous written conferencing package, "FirstClass," upon retention and success rates for Masters-level courses in a distance learning programme as compared with similar courses that were supported in a traditional manner using face-to-face tuition. The paper investigates the common…
The purpose of this case study was to compare the pedagogical and affective efficiency and efficacy of creative prose fiction writing workshops taught via asynchronous computer-mediated online distance education with creative prose fiction writing workshops taught face-to-face in order to better understand their operational pedagogy and…
Background: Spaced education (SE) is a novel, evidence-based form of online learning. We investigated whether an SE program following a face-to-face continuing medical education (CME) course could enhance the course's impact on providers' clinical behaviors. Methods: This randomized controlled trial was conducted from March 2009 to April 2010,…
Shaw, Timothy; Long, Andrea; Chopra, Sanjiv; Kerfoot, B. Price
Aims: Do college students' ratings of a professor's teaching effectiveness suggest that a professor's teaching improves with time? Does anything predict which instructors receive the highest ratings or improve the fastest? And, importantly, do the correlates of change differ across face-to-face and online courses? Methods: I used data from 10,392…
The present investigation was conducted to describe and compare the background variables, personal characteristics and academic performance of secondary teacher trainees in distance education and face-to-face mode. The results indicated that teacher trainees in distance education differed from their counterparts in age, marital status, sex and…
There is growing interest in understanding how different research methods are perceived by victims of violence and what survivors will reveal to researchers (termed "meta-research" or "meta-studies"). The purpose of this project was to conduct a qualitative meta-study on why rape survivors chose to participate in community-based, face-to-face…
Many new and important developmental issues are encountered during adolescence, which is also a time when Internet use becomes increasingly popular. Studies have shown that adolescents are using these online spaces to address developmental issues, especially needs for intimacy and connection to others. Online communication with its potential for…
Reich, Stephanie M.; Subrahmanyam, Kaveri; Espinoza, Guadalupe
Many individuals suffering from depression do not actively seek treatment. Self-help strategies represent low-threshold treatment options that are particularly relevant for milder cases. The present study addressed two important issues: (1) we examined depressed individuals' motives and attitudes that may represent barriers to face-to-face treatment; (2) we examined if the participation in an online treatment program facilitates or compromises their willingness to undergo face-to-face treatment. We recruited 210 participants with depression for a trial on the efficacy of an online treatment program for depression. Participants were randomly allocated either to a self-help treatment (Deprexis) or to a wait-list control group. All participants filled out a newly developed 42-item questionnaire called Psychotherapy Expectations, Concerns, and Hopes Inventory (PECHI). The scale measures attitudes toward face-to-face treatment and was administered at baseline and 8 weeks later. Principal component analysis of the PECHI revealed five dimensions: hope for symptomatic improvement, fear of poor alliance with the therapist, skill acquisition, skepticism and resentment of psychotherapy, and self-stigma. Attitudes toward treatment were stable over time and neither modulated by group status nor by self-reported or objective symptom decline. Correlation analyses revealed that current levels of depression and well-being were potent predictors of attitudes toward treatment, suggesting that when the patient feels more depressed, doubts about the effectiveness of therapy emerge more strongly. To conclude, results suggest that Deprexis neither promotes nor reduces negative attitudes toward psychotherapy, nor does it increase barriers to enter face-to-face treatments. An alarming paradox emerged: when a depressed person is in greatest need of help, motivation to seek face-to-face treatment is lowest. PMID:22930656
The current rise in online learning programs mandates that postsecondary faculty examine means of transferring successful, established critical thinking instructional strategies from the traditional classroom into the online environment. Theoretical arguments support, and even favor, the use of asynchronous learning technologies to promote students' critical thinking skills. The purpose of the current study is to examine students' application of critical
B. Jean Mandernach; Krista D. Forrest; Jamie L. Babutzke; Lanay R. Manker
The purpose of this research was to explore the use of ICT to support leadership learning within an education context. Leadership development opportunities that encourage reflection, the development of self-awareness, the sharing of practice, and that support the transfer of learning back to the workplace are challenging to fit into the life of…
Background Guided self-help is a recommended first-step treatment for bulimia nervosa, binge eating disorder and atypical variants of these disorders. Further research is needed to compare guided self-help that is delivered face-to-face versus via email. Methods/Design This clinical trial uses a randomised, controlled design to investigate the effectiveness of providing guided self-help either face-to-face or via e-mail, also using a delayed treatment control condition. At least 17 individuals are required per group, giving a minimum N of 51. Discussion Symptom outcomes will be assessed and estimates of cost-effectiveness made. Results are proposed to be disseminated locally and internationally (through submission to conferences and peer-reviewed journals), and will hopefully inform local service provision. The trial has been approved by an ethics review board and was registered with ClinicalTrials.gov NCT01832792 on 9 April 2013.
This study investigated the relationship between working alliance and problem resolution, among other variables, from the perspective of 102 coaches with psychology or counseling backgrounds. Results of the analyses suggested that coaches' perceptions of the working alliance were positively associated with problem resolution in both face-to-face and distance (e.g., phone) coaching. No significant differences were found in working alliance or
Rhonda M. Berry; Jeffrey S. Ashby; Philip B. Gnilka; Kenneth B. Matheny
Abstract Identifying tobacco use status is essential to address use and provide resources to help patients quit. Being able to collect this information in an electronic format will become increasingly important, as the Centers for Medicare and Medicaid Services has included the assessment of tobacco use as part of its Stage 1 Meaningful Use criteria. The objective was to compare the accuracy of online vs. paper assessment methods to ascertain cigarette smoking status using a face-to-face structured interview as the gold standard. This was a retrospective analysis of a stratified opportunity sample of consecutive patients, reporting in 2010 for a periodic health evaluation, who completed either a scannable paper-based form or an online questionnaire and underwent a standardized rooming interview. Compared with face-to-face structured interview, the overall observed agreement and kappa coefficient for both methods combined (paper and online) were 97.7% and 0.69 (95% confidence interval (CI) 0.51-0.86) . For the online form they were 97.4% and 0.61 (95% CI 0.33-0.90), and for the paper form they were 97.9% and 0.75 (95% CI 0.54-0.96). There was no statistically significant difference in agreement between the online and paper-based methods (P=0.76) compared with a face-to-face structured interview. Online assessment of tobacco use status is as accurate as a paper questionnaire, and both methods have greater than 97% observed agreement with a face-to-face structured interview. The use of online assessment of tobacco use status has several advantages and more widespread use should be explored. (Population Health Management 2014;17:185-189). PMID:24476559
Steffen, Mark W; Murad, Mohammad Hassan; Hays, J Taylor; Newcomb, Richard D; Molella, Robin G; Cha, Stephen S; Hagen, Philip T
We propose a wearable system that uses machine perception to quantify a user's social context and propagate this information to others in the user's social network. The social context is evaluated for the user's instantaneous, face-to- faceinteractions by evaluating proximity, collective speech features, head-movements, and galvanic skin responses. This information is then propagated to others within the user's social
Background Evidence-based psychological treatments, such as cognitive behavior therapy (CBT), have been found to be effective in treating several anxiety and mood disorders. Nevertheless, issues regarding adherence are common, such as poor patient compliance on homework assignments and therapists’ drifting from strictly evidence-based CBT. The development of Internet-delivered CBT (ICBT) has been intensive in the past decade and results show that guided ICBT can be as effective as face-to-face CBT but also indicate a need to integrate the two forms of CBT delivery. Objective In this study, we developed and tested a new treatment format in which ICBT and face-to-face therapy were blended. We designed a support system accessible via the Internet (using a computer or an Apple iPad) for patients and therapists delivering CBT face-to-face. The support system included basic CBT components and a library of interventions gathered from existing ICBT manuals. Methods The study involved 15 patients with mild to moderate anxiety or depression (or both). Eight therapists conducted the treatments. All participants were interviewed after the nine-week intervention. Further, patients provided self-reports on clinical measures pre- and post-trial, as well as at a 12-month follow-up. Results A reduction was found in symptom scores across all measures. The reliable change index ranged from 60% to 87% for depression and anxiety. Large effect sizes (Cohen’s d) ranging from 1.62 (CI 95% 0.59-2.66) to 2.43 (CI 95% 1.12-3.74) were found. There were no missing data and no treatment dropouts. In addition, the results had been maintained at the 12-month follow-up. Qualitative interviews revealed that the users perceived the support system as beneficial. Conclusions The results suggest that modern information technology can effectively blend with face-to-face treatments and be used to facilitate communication and structure in therapy, thus reducing therapist drift.
Cobalamin-independent methionine synthase (MetE) catalyzes the transfer of a methyl group from methyltetrahydrofolate to L-homocysteine (Hcy) without using an intermediate methyl carrier. Although MetE displays no detectable sequence homology with cobalamin-dependent methionine synthase (MetH), both enzymes require zinc for activation and binding of Hcy. Crystallographic analyses of MetE from T. maritima reveal an unusual dual-barrel structure in which the active site lies between the tops of the two (??)8 barrels. The fold of the N-terminal barrel confirms that it has evolved from the C-terminal polypeptide by gene duplication; comparisons of the barrels provide an intriguing example of homologous domain evolution in which binding sites are obliterated. The C-terminal barrel incorporates the zinc ion that binds and activates Hcy. The zinc-binding site in MetE is distinguished from the (Cys)3Zn site in the related enzymes, MetH and betaine–homocysteine methyltransferase, by its position in the barrel and by the metal ligands, which are histidine, cysteine, glutamate, and cysteine in the resting form of MetE. Hcy associates at the face of the metal opposite glutamate, which moves away from the zinc in the binary E·Hcy complex. The folate substrate is not intimately associated with the N-terminal barrel; instead, elements from both barrels contribute binding determinants in a binary complex in which the folate substrate is incorrectly oriented for methyl transfer. Atypical locations of the Hcy and folate sites in the C-terminal barrel presumably permit direct interaction of the substrates in a ternary complex. Structures of the binary substrate complexes imply that rearrangement of folate, perhaps accompanied by domain rearrangement, must occur before formation of a ternary complex that is competent for methyl transfer.
Purpose. This research study compared Internet-based distance learning versus face-to-face classroom using traditional undergraduate and continuing education adult students. The purpose of the study was to determine the effectiveness of Internet-based distance learning. The study examined whether there was any significant difference between an Internet-based distance-learning course and a face-to-face classroom course. Moreover, the study examined whether continuing-education adult students
Background Digital networks, mobile devices, and the possibility of mining the ever-increasing amount of digital traces that we leave behind in our daily activities are changing the way we can approach the study of human and social interactions. Large-scale datasets, however, are mostly available for collective and statistical behaviors, at coarse granularities, while high-resolution data on person-to-person interactions are generally limited to relatively small groups of individuals. Here we present a scalable experimental framework for gathering real-time data resolving face-to-face social interactions with tunable spatial and temporal granularities. Methods and Findings We use active Radio Frequency Identification (RFID) devices that assess mutual proximity in a distributed fashion by exchanging low-power radio packets. We analyze the dynamics of person-to-person interactionnetworks obtained in three high-resolution experiments carried out at different orders of magnitude in community size. The data sets exhibit common statistical properties and lack of a characteristic time scale from 20 seconds to several hours. The association between the number of connections and their duration shows an interesting super-linear behavior, which indicates the possibility of defining super-connectors both in the number and intensity of connections. Conclusions Taking advantage of scalability and resolution, this experimental framework allows the monitoring of social interactions, uncovering similarities in the way individuals interact in different contexts, and identifying patterns of super-connector behavior in the community. These results could impact our understanding of all phenomena driven by face-to-faceinteractions, such as the spreading of transmissible infectious diseases and information.
Cattuto, Ciro; Van den Broeck, Wouter; Barrat, Alain; Colizza, Vittoria; Pinton, Jean-Francois; Vespignani, Alessandro
This paper presents a qualitative case study of socialised blended learning, using a social network platform to investigate the level of literacies and interactions of students in a blended learning environment of traditional face-to-face design studio and online participatory teaching. Using student and staff feedback, the paper examines the use…
Epidemic spreading is of great importance in public health, as well as in related fields such as infrastructure. While complex network models have been used with great success to analyze epidemic behavior on single networks, the reality is that our world is made up of a system of interactingnetworks that do not necessarily share common characteristics. I introduce a model for constructing interactingnetworks and show that the phase transtion depends on the parameters ?T, kappaA and ?B, where ?T= / over the nodes in both networks, including internetwork links, and ?A and ?B are over the networks considered individually, with no internetwork links. For strongly interactingnetworks (?T> ?Aand ?B), there exists only one phase transition, between a disease-free phase and an epidemic phase across both networks. For weakly interactingnetworks (?T< ?A or ?B), a third, ``mixed,'' phase exists, where the disease enters an epidemic on one network alone. The analytic predictions are confirmed by Monte-Carlo simulations.
State-of-the-art treatment for weight management consists of a behavioral intervention to facilitate decreased energy intake and increased physical activity. These interventions are typically delivered face-to-face (FTF) by a health educator to a small group of participants. There are numerous barriers to participation in FTF clinics including availability, scheduling, the expense and time required to travel to the clinic site, and possible need for dependent care. Weight management clinics delivered by conference call have the potential to diminish or eliminate these barriers. The conference call approach may also reduce burden on providers, who could conduct clinic groups from almost any location without the expenses associated with maintaining FTF clinic space. A randomized trial will be conducted in 395 overweight/obese adults (BMI 25-39.9 kg/m(2)) to determine if weight loss (6 months) and weight maintenance (12 months) are equivalent between weight management interventions utilizing behavioral strategies and pre-packaged meals delivered by either a conference call or the traditional FTF approach. The primary outcome, body weight, will be assessed at baseline, 6, 12 and 18 months. Secondary outcomes including waist circumference, energy and macronutrient intake, and physical activity and will be assessed on the same schedule. In addition, a cost analysis and extensive process evaluation will be completed. PMID:22664647
Lambourne, Kate; Washburn, Richard A; Gibson, Cheryl; Sullivan, Debra K; Goetz, Jeannine; Lee, Robert; Smith, Bryan K; Mayo, Matthew S; Donnelly, Joseph E
Computer-assisted interview methods are increasingly popular in the assessment of sensitive behaviors (e.g., substance abuse and sexual behaviors). It has been suggested that the effect of social desirability is diminished when answering via computer, as compared to an interviewer-administered face-to-face (FTF) interview, although studies exploring this hypothesis among adolescents are rare and yield inconsistent findings. This study compared two interview modes among a sample of urban, ethnic-minority, perinatally HIV-exposed U.S. youth (baseline = 148 HIV+, 126 HIV?, ages 9–16 years; follow-up = 120 HIV+, 110 HIV?, ages 10–19 years). Participants were randomly assigned to receive a sexual behavior interview via either Audio Computer-Assisted Self-Interview (ACASI) or FTF interview. The prevalence of several sexual behaviors and participants’ reactions to the interviews were compared. Although higher rates of sexual behaviors were typically reported in the ACASI condition, the differences rarely reached statistical significance, even when limited to demographic subgroups—except for gender. Boys were significantly more likely to report several sexual behaviors in the ACASI condition compared to FTF, whereas among girls no significant differences were found between the two conditions. ACASI-assigned youth rated the interview process as easier and more enjoyable than did FTF-assigned youth, and this was fairly consistent across subgroup analyses as well. We conclude that these more positive reactions to the ACASI interview give that methodology a slight advantage, and boys may disclose more sexual behavior when using computer-assisted interviews.
Marhefka, Stephanie L.; Santamaria, E. Karina; Leu, Cheng-Shiun; Brackis-Cott, Elizabeth; Mellins, Claude Ann
Following some previous lines of thought held by the author on the role of politeness and related phenomena in face-to-face electoral debates, this article deals with a series of linguistic devices frequently used by participants in this adversarial genre, and commonly characterized as mitigated aggression, in order to determine their main strategic values in the context of both current politics
The study is aimed at investigating the effects of four learning methods on students' scientific inquiry skills. The four learning methods are: (a) metacognitive-guided inquiry within asynchronous learning networked technology (MINT); (b) an asynchronous learning network (ALN) with no metacognitive guidance; (c) metacognitive-guided inquiry embedded within face-to-face (F2F) interaction; and (d) F2F interaction with no metacognitive guidance. The study examined
The dispersion stability and the zeta potentials of nonspherical crystalline (beta-form) copper phthalocyanine (CuPc) particles of hydrodynamic diameter d(h) approximately = 90 nm were investigated at 25 degrees C in water and in aqueous solutions of NaNO(3). The electrolyte concentrations c ranged from 1 to 500 mM and the particle concentrations ranged from 50 to 10,000 ppm (0.005 to 1 wt %). In each case, the Fuchs-Smoluchowski stability ratio W was determined from dynamic light scattering (DLS) data and the Rayleigh-Debye-Gans (RDG) scattering theory. The data suggest that electrostatic effects play a major role in the stability of CuPc-based dispersions. The calculated particle charge z per CuPc particle based on the zeta potential data and the area of the particles (assumed to be cubical) suggests that there is preferential adsorption of NO(3)(-) ions on the uncharged CuPc surface, and the surface charge increases with increasing electrolyte concentration. Furthermore, two new models of the DLVO theory, for spheres and for parallel face-to-face cubes, were reformulated in dimensionless form. The Hamaker constant of CuPc particles was calculated by the same authors on the basis of theoretical models in J. Chem. Theory Comput. (2010, in press). The key dimensionless group is the ratio N of the electrostatic double layer energy to the Hamaker constant. The two DLVO models were used to predict the value of a dimensionless maximum potential energy Phi(max), the conditions when it may exist, and then the value of W. In water, the DLVO model for spheres overpredicted the stability, while the model for cubes underpredicted the stability. At c = 1 mM, both models overpredicted the stability. At c = 10 mM, the model for spheres underpredicted the stability, whereas the model for cubes overpredicted the stability. Hence, there seems to be some significant shape effects on the electrostatic stabilization of CuPc particle dispersions. At c = 100 and 500 mM, both models underpredicted the stability substantially, suggesting the existence of additional short-range repulsive forces, which may primarily control the stability. Simple sensitivity analysis on the calculations supported these conclusions. PMID:20073525
Dong, Jiannan; Corti, David S; Franses, Elias I; Zhao, Yan; Ng, Hou T; Hanson, Eric
Background This study aims to rank policy concerns and policy-related research issues in order to identify policy and research gaps on access to medicines (ATM) in low- and middle-income countries in Latin America and the Caribbean (LAC), as perceived by policy makers, researchers, NGO and international organization representatives, as part of a global prioritization exercise. Methods Data collection, conducted between January and May 2011, involved face-to-face interviews in El Salvador, Colombia, Dominican Republic, and Suriname, and an e-mail survey with key-stakeholders. Respondents were asked to choose the five most relevant criteria for research prioritization and to score policy/research items according to the degree to which they represented current policies, desired policies, current research topics, and/or desired research topics. Mean scores and summary rankings were obtained. Linear regressions were performed to contrast rankings concerning current and desired policies (policy gaps), and current and desired research (research gaps). Results Relevance, feasibility, and research utilization were the top ranked criteria for prioritizing research. Technical capacity, research and development for new drugs, and responsiveness, were the main policy gaps. Quality assurance, staff technical capacity, price regulation, out-of-pocket payments, and cost containment policies, were the main research gaps. There was high level of coherence between current and desired policies: coefficients of determination (R2) varied from 0.46 (Health system structure; r = 0.68, P <0.01) to 0.86 (Sustainable financing; r = 0.93, P <0.01). There was also high coherence between current and desired research on Rational selection and use of medicines (r = 0.71, P <0.05, R2 = 0.51), Pricing/affordability (r = 0.82, P <0.01, R2 = 0.67), and Sustainable financing (r = 0.76, P <0.01, R2 = 0.58). Coherence was less for Health system structure (r = 0.61, P <0.01, R2 = 0.38). Conclusions This study combines metrics approaches, contributing to priority setting methodology development, with country and regional level stakeholder participation. Stakeholders received feedback with the results, and we hope to have contributed to the discussion and implementation of ATM research and policy priorities in LAC.
Background To examine the trend of "mobile only" households, and households that have a mobile phone or landline telephone listed in the telephone directory, and to describe these groups by various socio-demographic and health indicators. Method Representative face-to-face population health surveys of South Australians, aged 15 years and over, were conducted in 1999, 2004, 2006, 2007 and 2008 (n = 14285, response rates = 51.9% to 70.6%). Self-reported information on mobile phone ownership and usage (1999 to 2008) and listings in White Pages telephone directory (2006 to 2008), and landline telephone connection and listings in the White Pages (1999 to 2008), was provided by participants. Additional information was collected on self-reported health conditions and health-related risk behaviours. Results Mobile only households have been steadily increasing from 1.4% in 1999 to 8.7% in 2008. In terms of sampling frame for telephone surveys, 68.7% of South Australian households in 2008 had at least a mobile phone or landline telephone listed in the White Pages (73.8% in 2006; 71.5% in 2007). The proportion of mobile only households was highest among young people, unemployed, people who were separated, divorced or never married, low income households, low SES areas, rural areas, current smokers, current asthma or people in the normal weight range. The proportion with landlines or mobiles telephone numbers listed in the White Pages telephone directory was highest among older people, married or in a defacto relationship or widowed, low SES areas, rural areas, people classified as overweight, or those diagnosed with arthritis or osteoporosis. Conclusion The rate of mobile only households has been increasing in Australia and is following worldwide trends, but has not reached the high levels seen internationally (12% to 52%). In general, the impact of mobile telephones on current sampling frames (exclusion or non-listing of mobile only households or not listed in the White Pages directory) may have a low impact on health estimates obtained using telephone surveys. However, researchers need to be aware that mobile only households are distinctly different to households with a landline connection, and the increase in the number of mobile-only households is not uniform across all groups in the community. Listing in the White Pages directory continues to decrease and only a small proportion of mobile only households are listed. Researchers need to be aware of these telephone sampling issues when considering telephone surveys.
Several scenarios of interacting neural networks which are trained either in an identical or in a competitive way are solved analytically. In the case of identical training each perceptron receives the output of its neighbour. The symmetry of the stationary state as well as the sensitivity to the used training algorithm are investigated. Two competitive perceptrons trained on mutually exclusive
Offered by the National Oceanic and Atmospheric Administration (NOAA), the Interactive Weather Information Network (IWIN) is a collection of interactive weather maps and satellite images that is updated every five seconds. Visitors can see cloud cover animation loops, NEXRAD Radar images of precipitation, a map of all current weather fronts, and an interactive national map to see information about any particular state. Other information on the site includes a listing of any active weather warnings, a link for world weather data, and more, making this a must-see site for all those users interested in the most current weather happenings anywhere.
Empathy allows emotional psychological inference about other person's mental states and feelings in social contexts. We aimed at specifying the common and differential neural mechanisms of self- and other-related attribution of emotional states using event-related functional magnetic resonance imaging. Subjects viewed faces expressing emotions with direct or averted gaze and either focused on their own emotional response to each face
Martin Schulte-rüther; Hans J. Markowitsch; Gereon R. Fink; Martina Piefke
Background Most patients with mild to moderate depression receive treatment in primary care, but despite guideline recommendations, structured psychological interventions are infrequently delivered. Research supports the effectiveness of Internet-based treatment for depression; however, few trials have studied the effect of the MoodGYM program plus therapist support. The use of such interventions could improve the delivery of treatment in primary care. Objective To evaluate the effectiveness and acceptability of a guided Web-based intervention for mild to moderate depression, which could be suitable for implementation in general practice. Methods Participants (N=106) aged between 18 and 65 years were recruited from primary care and randomly allocated to a treatment condition comprising 6 weeks of therapist-assisted Web-based cognitive behavioral therapy (CBT), or to a 6-week delayed treatment condition. The intervention included the Norwegian version of the MoodGYM program, brief face-to-face support from a psychologist, and reminder emails. The primary outcome measure, depression symptoms, was measured by the Beck Depression Inventory-II (BDI-II). Secondary outcome measures included the Beck Anxiety Inventory (BAI), the Hospital Anxiety and Depression Scale (HADS), the Satisfaction with Life Scale (SWLS), and the EuroQol Group 5-Dimension Self-Report Questionnaire (EQ-5D). All outcomes were based on self-report and were assessed at baseline, postintervention, and at 6-month follow-up. Results Postintervention measures were completed by 37 (71%) and 47 (87%) of the 52 participants in the intervention and 54 participants in the delayed treatment group, respectively. Linear mixed-models analyses revealed a significant difference in time trends between the groups for the BDI-II, (P=.002), for HADS depression and anxiety subscales (P<.001 and P=.001, respectively), and for the SWLS (P<.001). No differential group effects were found for the BAI and the EQ-5D. In comparison to the control group, significantly more participants in the intervention group experienced recovery from depression as measured by the BDI-II. Of the 52 participants in the treatment program, 31 (60%) adhered to the program, and overall treatment satisfaction was high. The reduction of depression and anxiety symptoms was largely maintained at 6-month follow-up, and positive gains in life satisfaction were partly maintained. Conclusions The intervention combining MoodGYM and brief therapist support can be an effective treatment of depression in a sample of primary care patients. The intervention alleviates depressive symptoms and has a significant positive effect on anxiety symptoms and satisfaction with life. Moderate rates of nonadherence and predominately positive evaluations of the treatment also indicate the acceptability of the intervention. The intervention could potentially be used in a stepped-care approach, but remains to be tested in regular primary health care. Trial Registration Australian New Zealand Clinical Trials Registry: ACTRN12610000257066; http://apps.who.int/trialsearch/trial.aspx?trialid=ACTRN12610000257066 (Archived by WebCite at http://www.webcitation.org/6Ie3YhIZa).
Lillevoll, Kjersti R; Griffiths, Kathleen M; Wilsgaard, Tom; Eisemann, Martin; Waterloo, Knut; Kolstrup, Nils
In this contribution we give an overview over recent work on the theory of interacting neural networks. The model is defined in Section 2. The typical teacher\\/student scenario is considered in Section 3. A static teacher network is presenting training examples for an adaptive student network. In the case of multilayer networks, the student shows a transition from a symmetric
The original publication is available from www.springerlink.com.\\u000aSloep, P. (2009). Social Interaction in Learning Networks. In R. Koper (Ed.), Learning Network Services for Professional Development (pp 13-15). Berlin, Germany: Springer Verlag.
Dynamical social networks are evolving rapidly and are highly adaptive. Characterizing the information encoded in social networks is essential to gain insight into the structure, evolution, adaptability and dynamics. Recently entropy measures have been used to quantify the information in email correspondence, static networks and mobility patterns. Nevertheless, we still lack methods to quantify the information encoded in time-varying dynamical social networks. In this talk we present a model to quantify the entropy of dynamical social networks and use this model to analyze the data of phone-call communication. We show evidence that the entropy of the phone-call interactionnetwork changes according to circadian rhythms. Moreover we show that social networks are extremely adaptive and are modified by the use of technologies such as mobile phone communication. Indeed the statistics of duration of phone-call is described by a Weibull distribution and is significantly different from the distribution of duration of face-to-faceinteractions in a conference. Finally we investigate how much the entropy of dynamical social networks changes in realistic models of phone-call or face-tofaceinteractions characterizing in this way different type human social behavior.
Service systems rely on internal interactions of service provider agents and the external interactions with customers in the design and delivery of services. Careful analysis and modeling of such interactions are essential to the design of effective service systems. This paper focuses on service interactionnetworks in the context of the design and delivery of complex, IT-centric services. More specifically,
We introduce a graph generating model aimed at representing the evolution of protein interactionnetworks. The model is based on the hypotesis of evolution by duplications and divergence of the genes which produce proteins. The obtained graphs shows multifractal properties recovering the absence of a characteristic connectivity as found in real data of protein interactionnetworks. The error tolerance of
Alexei Vazquez; A. Flammini; A. Maritan; A. Vespignani
We introduce a graph-generating model aimed at representing the evolution of protein interactionnetworks. The model is based on the hypothesis of evolution by duplication and divergence of the genes which produce proteins. The obtained graphs have multifractal properties recovering the absence of a characteristic connectivity as found in real data of protein interactionnetworks. The error tolerance of the
Each student has a unique learning style or individual way of perceiving, interacting, and responding to a learning environment. The purpose of this study was to identify and compare the prevalence of learning styles among undergraduate Sport Management Studies (SMS) students at California University of Pennsylvania (Cal U). Learning style…
Recently, the focus of network research shifted to network controllability, prompting us to determine proteins that are important for the control of the underlying interaction webs. In particular, we determined minimum dominating sets of proteins (MDSets) in human and yeast protein interactionnetworks. Such groups of proteins were defined as optimized subsets where each non-MDSet protein can be reached by an interaction from an MDSet protein. Notably, we found that MDSet proteins were enriched with essential, cancer-related, and virus-targeted genes. Their central position allowed MDSet proteins to connect protein complexes and to have a higher impact on network resilience than hub proteins. As for their involvement in regulatory functions, MDSet proteins were enriched with transcription factors and protein kinases and were significantly involved in bottleneck interactions, regulatory links, phosphorylation events, and genetic interactions. PMID:24778220
Recently, the focus of network research shifted to network controllability, prompting us to determine proteins that are important for the control of the underlying interaction webs. In particular, we determined minimum dominating sets of proteins (MDSets) in human and yeast protein interactionnetworks. Such groups of proteins were defined as optimized subsets where each non-MDSet protein can be reached by an interaction from an MDSet protein. Notably, we found that MDSet proteins were enriched with essential, cancer-related, and virus-targeted genes. Their central position allowed MDSet proteins to connect protein complexes and to have a higher impact on network resilience than hub proteins. As for their involvement in regulatory functions, MDSet proteins were enriched with transcription factors and protein kinases and were significantly involved in bottleneck interactions, regulatory links, phosphorylation events, and genetic interactions.
Molecular interactions are often represented as network models which have become the common language of many areas of biology. Graphs serve as convenient mathematical representations of network models and have themselves become objects of study. Their topology has been intensively researched over the last decade after evidence was found that they share underlying design principles with many other types of networks.Initial studies suggested that molecular interactionnetwork topology is related to biological function and evolution. However, further whole-network analyses did not lead to a unified view on what this relation may look like, with conclusions highly dependent on the type of molecular interactions considered and the metrics used to study them. It is unclear whether global network topology drives function, as suggested by some researchers, or whether it is simply a byproduct of evolution or even an artefact of representing complex molecular interactionnetworks as graphs.Nevertheless, network biology has progressed significantly over the last years. We review the literature, focusing on two major developments. First, realizing that molecular interactionnetworks can be naturally decomposed into subsystems (such as modules and pathways), topology is increasingly studied locally rather than globally. Second, there is a move from a descriptive approach to a predictive one: rather than correlating biological network topology to generic properties such as robustness, it is used to predict specific functions or phenotypes.Taken together, this change in focus from globally descriptive to locally predictive points to new avenues of research. In particular, multi-scale approaches are developments promising to drive the study of molecular interactionnetworks further. PMID:24041013
Winterbach, Wynand; Van Mieghem, Piet; Reinders, Marcel; Wang, Huijuan; de Ridder, Dick
The integration of technology into the K--12 classroom has become a key focus in the last several years. However, teachers are often left out of this integration process, and subsequently training in the use of the technologies in a classroom setting is often minimal in nature. Teachers are left on their own as they struggle to integrate technology into their curriculum. Web-based professional development has the potential to alleviate both time and place constraints teachers often confront when trying to attend traditional professional programs to upgrade their technology skills. This study focuses on 70 upper elementary, middle, and high school teachers who volunteered to take part in this study in which a web-based tutorial was used as a tool for professional development and data collection. A comparison of settings allowed these teachers to participate in one of three ways: (1) in a workshop-type setting with an instructional leader; (2) in a workshop-type setting with a facilitator; and (3) on the web without an instructional leader or informal peer interaction. All the groups used the same web-based tutorial on water quality monitoring for instructional purposes. Research data included pretest and post-test measurement from all three groups as well as their analysis of a known water sample. The Microcomputer Utilization in Teaching Efficacy Beliefs Instrument (MUTEBI) was administered to all the participants as a measurement of self-efficacy beliefs as they relate to the use of computers in science teaching. In addition to the quantitative data collected, qualitative data was also compiled. The results of the study indicate that all the participants were equal in terms of knowledge acquisition, but may have derived "unanticipated benefits" from interaction with their peers in the workshop-type settings. The results also indicate that as teachers' self-rating of computer expertise increased, their scores on the Microcomputer Utilization in Teaching Efficacy Beliefs Instrument (MUTEBI) increased as well.
Human–human interaction in natural environments relies on a variety of perceptual cues. Humanoid robots are becoming increasingly refined in their sensorimotor capabilities, and thus should now be able to manipulate and exploit these social cues in cooperation with their human partners. Previous studies have demonstrated that people follow human and robot gaze, and that it can help them to cope with spatially ambiguous language. Our goal is to extend these findings into the domain of action, to determine how human and robot gaze can influence the speed and accuracy of human action. We report on results from a human–human cooperation experiment demonstrating that an agent’s vision of her/his partner’s gaze can significantly improve that agent’s performance in a cooperative task. We then implement a heuristic capability to generate such gaze cues by a humanoid robot that engages in the same cooperative interaction. The subsequent human–robot experiments demonstrate that a human agent can indeed exploit the predictive gaze of their robot partner in a cooperative task. This allows us to render the humanoid robot more human-like in its ability to communicate with humans. The long term objectives of the work are thus to identify social cooperation cues, and to validate their pertinence through implementation in a cooperative robot. The current research provides the robot with the capability to produce appropriate speech and gaze cues in the context of human–robot cooperation tasks. Gaze is manipulated in three conditions: Full gaze (coordinated eye and head), eyes hidden with sunglasses, and head fixed. We demonstrate the pertinence of these cues in terms of statistical measures of action times for humans in the context of a cooperative task, as gaze significantly facilitates cooperation as measured by human response times.
This study explored how social networking technology can be used to supplement face-to-face courses as a means of enhancing students' sense of community and, thus, to promote classroom communities of practice in the context of higher education. Data were collected from 67 students who enrolled in four face-to-face courses at two public…
In January the 157 Group launched a policy paper making the case for professional careers guidance. With the launch of the National Careers Service in April, information, advice and guidance is a hot topic within the education and skills sector and one that is regularly debated. The combination of policy changes, including the introduction of…
Compared the effectiveness of a programmed self-counseling manual and a normal precollege counseling interview by 4 experienced counselors for 392 students. Ss preferred normal counseling but also rated programmed counseling favorably. Coverage of student problems was higher for programmed counseling, while flexibility was somewhat greater for normal counseling. Self-concepts, E.g., estimates of abilities, interests, suitability of ability and interest for
During face-to-faceinteractions typically developing individuals use gaze aversion (GA), away from their questioner, when thinking. GA is also used when individuals with autism (ASD) and Williams syndrome (WS) are thinking during question-answer interactions. We investigated GA strategies during face-to-face social style interactions with…
Doherty-Sneddon, Gwyneth; Whittle, Lisa; Riby, Deborah M.
This thesis employs methods of statistical mechanics and numerical simulations to study some aspects of dynamic and interacting complex networks. The mapping of various social and physical phenomena to complex networks has been a rich field in the past few decades. Subjects as broad as petroleum engineering, scientific collaborations, and the structure of the internet have all been analyzed in a network physics context, with useful and universal results. In the first chapter we introduce basic concepts in networks, including the two types of network configurations that are studied and the statistical physics and epidemiological models that form the framework of the network research, as well as covering various previously-derived results in network theory that are used in the work in the following chapters. In the second chapter we introduce a model for dynamic networks, where the links or the strengths of the links change over time. We solve the model by mapping dynamic networks to the problem of directed percolation, where the direction corresponds to the time evolution of the network. We show that the dynamic network undergoes a percolation phase transition at a critical concentration pc, that decreases with the rate r at which the network links are changed. The behavior near criticality is universal and independent of r. We find that for dynamic random networks fundamental laws are changed: i) The size of the giant component at criticality scales with the network size N for all values of r, rather than as N2/3 in static network, ii) In the presence of a broad distribution of disorder, the optimal path length between two nodes in a dynamic network scales as N1/2, compared to N1/3 in a static network. The third chapter consists of a study of the effect of quarantine on the propagation of epidemics on an adaptive network of social contacts. For this purpose, we analyze the susceptible-infected-recovered model in the presence of quarantine, where susceptible individuals protect themselves by disconnecting their links to infected neighbors with probability w and reconnecting them to other susceptible individuals chosen at random. Starting from a single infected individual, we show by an analytical approach and simulations that there is a phase transition at a critical rewiring (quarantine) threshold wc separating a phase (w < wc) where the disease reaches a large fraction of the population from a phase (w > wc) where the disease does not spread out. We find that in our model the topology of the network strongly affects the size of the propagation and that wc increases with the mean degree and heterogeneity of the network. We also find that wc is reduced if we perform a preferential rewiring, in which the rewiring probability is proportional to the degree of infected nodes. In the fourth chapter, we study epidemic processes on interconnected network systems, and find two distinct regimes. In strongly-coupled network systems, epidemics occur simultaneously across the entire system at a critical value betac. In contrast, in weakly-coupled network systems, a mixed phase exists below betac where an epidemic occurs in one network but does not spread to the coupled network. We derive an expression for the network and disease parameters that allow this mixed phase and verify it numerically. Public health implications of communities comprising these two classes of network systems are also mentioned.
The study of neural networks is enjoying a great renaissance, both in computational neuroscience, the development of information processing models of living brains, and in neural computing, the use of neurally inspired concepts in the construction of intelligent machines. This volume presents models and data on the dynamic interactions occurring in the brain, and exhibits the dynamic interactions between research in computational neuroscience and in neural computing. The authors present current research, future trends and open problems.
Arbib, M.A. (Univ. of Southern California (US)); Amari, S. (Tokyo Univ. (Japan))
We introduce a graph generating model aimed at representing the evolution of\\u000aprotein interactionnetworks. The model is based on the hypotesis of evolution\\u000aby duplications and divergence of the genes which produce proteins. The\\u000aobtained graphs shows multifractal properties recovering the absence of a\\u000acharacteristic connectivity as found in real data of protein interaction\\u000anetworks. The error tolerance of
Audio computer-assisted survey instrument (ACASI) has been shown to decrease under-reporting of socially undesirable behaviours, but has not been evaluated in pregnant women at risk of HIV acquisition in Brazil. We assigned HIV-negative pregnant women receiving routine antenatal care at in Porto Alegre, Brazil and their partners to receive a survey regarding high-risk sexual behaviours and drug use via ACASI (n = 372) or face-to-face (FTF) (n = 283) interviews. Logistic regression showed that compared with FTF, pregnant women interviewed via ACASI were significantly more likely to self-report themselves as single (14% versus 6%), having >5 sexual partners (35% versus 29%), having oral sex (42% versus 35%), using intravenous drugs (5% versus 0), smoking cigarettes (23% versus 16%), drinking alcohol (13% versus 8%) and using condoms during pregnancy (32% versus 17%). Therefore, ACASI may be a useful method in assessing risk behaviours in pregnant women, especially in relation to drug and alcohol use. PMID:23970659
Yeganeh, N; Dillavou, C; Simon, M; Gorbach, P; Santos, B; Fonseca, R; Saraiva, J; Melo, M; Nielsen-Saines, K
Smoking cessation interventions for cardiac patients need improvement given their weak effects on long-term abstinence rates and low compliance by nurses to implementation. This study tested the effectiveness of two smoking cessation interventions against usual care in cardiac patients, and conditional effects for patients' motivation to quit and socio-economic status (SES). An experimental study was conducted from 2009 to 2012 for which Dutch cardiac patient smokers were assigned to: usual care (UC; n = 245), telephone counseling (TC; n = 223) or face-to-face counseling (FC; n = 157). The three groups were comparable at baseline and had smoked on average 21 cigarettes a day before hospitalization. After six months, interviews occurred to assess self-reported smoking status. Patients in the TC and FC group had significantly higher smoking abstinence rates than patients in the UC group (p ? 0.05 at all times). Regression analysis further revealed significant conditional effects of the interventions on smoking abstinence in patients with lower SES, with a larger effect for TC than FC when compared to UC. These findings suggest that intensive counseling is effective in increasing short-term abstinence rates, particularly in patients with lower SES. Future studies need to investigate how patients with higher SES can profit equally from these type of interventions. PMID:23760610
Berndt, Nadine; Bolman, Catherine; Froelicher, Erika Sivarajan; Mudde, Aart; Candel, Math; de Vries, Hein; Lechner, Lilian
We describe two novel methods for predicting protein interactions, using only the topology of an observed protein interactionnetwork. The first method searches the protein interactionnetwork for defective cliques (i.e. nearly complete complexes of pair wise interacting proteins), and predicts the interactions that complete them. The second method computes the diffusion distance between each pair of proteins and then
Alberto Paccanarot; Valery Trifonovl; Haiyuan Yut; Mark Gerstein
Background Panic disorder (PD) is one of the most common anxiety disorders seen in general practice, but provision of evidence-based cognitive-behavioural treatment (CBT) is rare. Many Australian GPs are now trained to deliver focused psychological strategies, but in practice this is time consuming and costly. Objective To evaluate the efficacy of an internet-based CBT intervention (Panic Online) for the treatment of PD supported by general practitioner (GP)-delivered therapeutic assistance. Design Panic Online supported by GP-delivered face-to-face therapy was compared to Panic Online supported by psychologist-delivered email therapy. Methods Sixty-five people with a primary diagnosis of PD (78% of whom also had agoraphobia) completed 12 weeks of therapy using Panic Online and therapeutic assistance with his/her GP (n = 34) or a clinical psychologist (n = 31). The mean duration of PD for participants allocated to these groups was 59 months and 58 months, respectively. Participants completed a clinical diagnostic interview delivered by a psychologist via telephone and questionnaires to assess panic-related symptoms, before and after treatment. Results The total attrition rate was 20%, with no group differences in attrition frequency. Both treatments led to significant improvements in panic attack frequency, depression, anxiety, stress, anxiety sensitivity and quality of life. There were no statistically significant differences in the two treatments on any of these measures, or in the frequency of participants with clinically significant PD at post assessment. Conclusions When provided with accessible online treatment protocols, GPs trained to deliver focused psychological strategies can achieve patient outcomes comparable to efficacious treatments delivered by clinical psychologists. The findings of this research provide a model for how GPs may be assisted to provide evidence-based mental healthcare successfully.
Discusses multipoint interactive video networks and describes experiences with two networks in North Carolina, the MCNC CONCERT (COmmunications network of North Carolina for Education, Research, and Technology) and the Vision Carolina network. Digital video is explained, and issues concerning various components of the telecommunications industry…
The recent availability of large-scale protein-protein interaction data provides new opportunities for characterizing a protein's function within the context of its cellular interactions, pathways and networks. In this paper, we review computational approaches that have been developed for analyzing protein interactionnetworks in order to predict protein function.
A major issue in biology is the understanding of the interactions between proteins. These interactions can be described by a network, where the proteins are modeled by nodes and the interactions by edges. The origin of these protein networks is not well understood yet. Here we present a two-step model, which generates clusters with the same topological properties as networks for protein-protein interactions, namely, the same degree distribution, cluster size distribution, clustering coefficient, and shortest path length. The biological and model networks are not scale-free but exhibit small-world features. The model allows the fitting of different biological systems by tuning a single parameter.
Schneider, Christian M.; de Arcangelis, Lucilla; Herrmann, Hans J.
Recent results on the statistical physics of time series generation and prediction are presented. A neural network is trained on quasi-periodic and chaotic sequences and overlaps to the sequence generator as well as the prediction errors are calculated numerically. For each network there exists a sequence for which it completely fails to make predictions. Two interactingnetworks show a transition
This paper details how the Interactive Electronic Network is being utilized by secondary and postsecondary students, and their teachers and professors, to facilitate learning and understanding. The Interactive Electronic Network is couched within the Explorers of the Universe web site in a restricted portion entitled Gateway.
Communication networks consist of the regular patterns of interpersonal communication contacts which develop among people within an organization as they use various forms of communication (face-to-face meetings, memos, telephone calls, etc.) to accomplish...
Many specific physical networks (e.g., internet, power grid, interstates), have been characterized in considerable detail, but in isolation from each other. Yet, each of these networks supports the functions of the others, and so far, little is known about how their interactions affect their structure and functionality. To address this issue, we consider two coupled model networks. Each network is relatively simple, with a fixed set of nodes, but dynamically generated set of links which has a preferred degree, ?. In the stationary state, the degree distribution has exponential tails (far from ?), an attribute which we can explain. Next, we consider two such networks with different ?'s, reminiscent of two social groups, e.g., extroverts and introverts. Finally, we let these networksinteract by establishing a controllable fraction of cross links. The resulting distribution of links, both within and across the two model networks, is investigated and discussed, along with some potential consequences for real networks.
Liu, Wenjia; Jolad, Shivakumar; Schmittmann, Beate; Zia, R. K. P.
We present a novel algorithm combining artificial neural networks and swarm intelligence (SI) methods to infer networkinteractions. The algorithm uses ant colony optimization (ACO) to identify the optimal architecture of a recurrent neural network (RNN), while the weights of the RNN are optimized using particle swarm optimization (PSO). Our goal is to construct an RNN that mimics the true structure of an unknown network and the time-series data that the network generated. We applied the proposed hybrid SI-RNN algorithm to infer a simulated genetic network. The results indicate that the algorithm has a promising potential to infer complex interactions such as gene regulatory networks from time-series gene expression data. PMID:17946231
The concept of vulnerability is introduced for a model of random, dynamical interactions on networks. In this model, known as the influence model, the nodes are arranged in an arbitrary network, while the evolution of the status at a node is according to an internal Markov chain, but with transition probabilities that depend not only on the current status of that node but also on the statuses of the neighbouring nodes. Vulnerability is treated analytically and numerically for several networks with different topological structures, as well as for two real networks--the network of infrastructures and the EU power grid--identifying the most vulnerable nodes of these networks. PMID:20368242
Background Network analyses of plant-animal interactions hold valuable biological information. They are often used to quantify the degree of specialization between partners, but usually based on qualitative indices such as 'connectance' or number of links. These measures ignore interaction frequencies or sampling intensity, and strongly depend on network size. Results Here we introduce two quantitative indices using interaction frequencies to describe the degree of specialization, based on information theory. The first measure (d') describes the degree of interaction specialization at the species level, while the second measure (H2') characterizes the degree of specialization or partitioning among two parties in the entire network. Both indices are mathematically related and derived from Shannon entropy. The species-level index d' can be used to analyze variation within networks, while H2' as a network-level index is useful for comparisons across different interaction webs. Analyses of two published pollinator networks identified differences and features that have not been detected with previous approaches. For instance, plants and pollinators within a network differed in their average degree of specialization (weighted mean d'), and the correlation between specialization of pollinators and their relative abundance also differed between the webs. Rarefied sampling effort in both networks and null model simulations suggest that H2' is not affected by network size or sampling intensity. Conclusion Quantitative analyses reflect properties of interactionnetworks more appropriately than previous qualitative attempts, and are robust against variation in sampling intensity, network size and symmetry. These measures will improve our understanding of patterns of specialization within and across networks from a broad spectrum of biological interactions.
The importance of understanding biological interactionnetworks has fueled the development of numerous interaction data generation techniques, databases and prediction tools. However not all prediction tools and databases predict interactions with one hundred percent accuracy. Generation of high confidence interactionnetworks formulates the first step towards deciphering unknown protein functions, determining protein complexes and inventing drugs. The CABIN: Collective Analysis of Biological InteractionNetworks software is an exploratory data analysis tool that enables analysis and integration of interactions evidence obtained from multiple sources, thereby increasing the confidence of computational predictions as well as validating experimental observations. CABIN has been written in JavaTM and is available as a plugin for Cytoscape – an open source network visualization tool.
Two neural networks which are trained on their mutual output bits are analysed using methods of statistical physics. The exact\\u000a solution of the dynamics of the two weight vectors shows a novel phenomenon: The networks synchronize to a state with identical\\u000a time dependent weights. Extending the models to multilayer networks with discrete weights, it is shown how synchronization\\u000a by mutual
We presented a network comparison algorithm for predicting the conservative interaction regions in the cross-species protein-protein interactionnetworks (PINs). In the first place, We made use of the correlated matrix to represent the PINs. Then we standardized the matrix and changed it into a unique representation to facilitate to judge whether the subgraphs is isomorphic. Then we proposed a network
Identifying and removing spurious links in complex networks is meaningful for many real applications and is crucial for improving the reliability of network data, which, in turn, can lead to a better understanding of the highly interconnected nature of various social, biological, and communication systems. In this paper, we study the features of different simple spurious link elimination methods, revealing that they may lead to the distortion of networks' structural and dynamical properties. Accordingly, we propose a hybrid method that combines similarity-based index and edge-betweenness centrality. We show that our method can effectively eliminate the spurious interactions while leaving the network connected and preserving the network's functionalities. PMID:22587143
Determining the network of physical protein associations is an important first step in developing mechanistic evidence for elucidating biological pathways. Despite rapid advances in the field of high throughput experiments to determine protein interactions, the majority of associations remain unknown. Here we describe computational methods for significantly expanding protein association networks. We describe methods for integrating multiple independent sources of
J. G. Lees; J. K. Heriche; I. Morilla; J. A. Ranea; C. A. Orengo
BACKGROUND: The local connectivity and global position of a protein in a protein interactionnetwork are known to correlate with some of its functional properties, including its essentiality or dispensability. It is therefore of interest to extend this observation and examine whether network properties of two proteins considered simultaneously can determine their joint dispensability, i.e., their propensity for synthetic sick\\/lethal
Sri R. Paladugu; Shan Zhao; Animesh Ray; Alpan Raval
We have combined four different types of functional genomic data to create high coverage protein interactionnetworks for 11 mi- crobes. Our integration algorithm naturally handles statistically depen- dent predictors and automatically corrects for differing noise levels and data corruption in different evidence sources. We find that many of the predictions in each integrated network hinge on moderate but consis-
Balaji S. Srinivasan; Antal F. Novak; Jason A. Flannick; Serafim Batzoglou; Harley H. Mcadams
In general, the Linux 2.6 scheduler can ensure fairness and provide excellent interactive performance at the same time. However, our experiments and mathematical analysis have shown that the current Linux interactivity mechanism tends to incorrectly categorize non-interactivenetwork applications as interactive, which can lead to serious fairness or starvation issues. In the extreme, a single process can unjustifiably obtain up to 95% of the CPU! The root cause is due to the facts that: (1) network packets arrive at the receiver independently and discretely, and the 'relatively fast' non-interactivenetwork process might frequently sleep to wait for packet arrival. Though each sleep lasts for a very short period of time, the wait-for-packet sleeps occur so frequently that they lead to interactive status for the process. (2) The current Linux interactivity mechanism provides the possibility that a non-interactivenetwork process could receive a high CPU share, and at the same time be incorrectly categorized as 'interactive.' In this paper, we propose and test a possible solution to address the interactivity vs. fairness problems. Experiment results have proved the effectiveness of the proposed solution.
Protein interactionnetworks summarize large amounts of protein–protein interaction data, both from individual, small-scale experiments and from automated high-throughput screens. The past year has seen a flood of new experimental data, especially on metazoans, as well as an increasing number of analyses designed to reveal aspects of network topology, modularity and evolution. As only minimal progress has been made in
Peer Bork; Lars J Jensen; Christian von Mering; Arun K Ramani; Insuk Lee; Edward M Marcotte
Embryonic stem cells have the ability to differentiate into nearly all cell types. However, the molecular mechanism of its pluripotency is still unclear. Oct3/4, Sox2 and Nanog are important factors of pluripotency. Oct3/4 (hereafter referred to as Oct4), in particular, has been an irreplaceable factor in the induction of pluripotency in adult cells. Proteins interacting with Oct4 and Nanog have been identified via affinity purification and mass spectrometry. These data, together with iterative purifications of interacting proteins allowed a protein interactionnetwork to be constructed. The network currently includes 77 transcription factors, all of which are interconnected in one network. In-depth studies of some of these transcription factors show that they all recruit the NuRD complex. Hence, transcription factor clustering and chromosomal remodeling are key mechanism used by embryonic stem cells. Studies using RNA interference suggest that more pluripotency genes are yet to be discovered via protein-protein interactions. More work is required to complete and curate the embryonic stem cell protein interactionnetwork. Analysis of a saturated protein interactionnetwork by system biology tools can greatly aid in the understanding of the embryonic stem cell pluripotency network.
We investigate interactionnetworks that we derive from multivariate time series with methods frequently employed in diverse scientific fields such as biology, quantitative finance, physics, earth and climate sciences, and the neurosciences. Mimicking experimental situations, we generate time series with finite length and varying frequency content but from independent stochastic processes. Using the correlation coefficient and the maximum cross-correlation, we estimate interdependencies between these time series. With clustering coefficient and average shortest path length, we observe unweighted interactionnetworks, derived via thresholding the values of interdependence, to possess non-trivial topologies as compared to Erdös-Rényi networks, which would indicate small-world characteristics. These topologies reflect the mostly unavoidable finiteness of the data, which limits the reliability of typically used estimators of signal interdependence. We propose random networks that are tailored to the way interactionnetworks are derived from empirical data. Through an exemplary investigation of multichannel electroencephalographic recordings of epileptic seizures – known for their complex spatial and temporal dynamics – we show that such random networks help to distinguish network properties of interdependence structures related to seizure dynamics from those spuriously induced by the applied methods of analysis.
Bialonski, Stephan; Wendler, Martin; Lehnertz, Klaus
Background In spite of the scale-free degree distribution that characterizes most protein interactionnetworks (PINs), it is common to define an ad hoc degree scale that defines “hub” proteins having special topological and functional significance. This raises the concern that some conclusions on the functional significance of proteins based on network properties may not be robust. Methodology In this paper we present three objective methods to define hub proteins in PINs: one is a purely topological method and two others are based on gene expression and function. By applying these methods to four distinct PINs, we examine the extent of agreement among these methods and implications of these results on network construction. Conclusions We find that the methods agree well for networks that contain a balance between error-free and unbiased interactions, indicating that the hub concept is meaningful for such networks.
In a context of global changes, and amidst the perpetual modification of community structure undergone by most natural ecosystems, it is more important than ever to understand how species interactions vary through space and time. The integration of biogeography and network theory will yield important results and further our understanding of species interactions. It has, however, been hampered so far by the difficulty to quantify variation among interactionnetworks. Here, we propose a general framework to study the dissimilarity of species interactionnetworks over time, space or environments, allowing both the use of quantitative and qualitative data. We decompose network dissimilarity into interactions and species turnover components, so that it is immediately comparable to common measures of ?-diversity. We emphasise that scaling up ?-diversity of community composition to the ?-diversity of interactions requires only a small methodological step, which we foresee will help empiricists adopt this method. We illustrate the framework with a large dataset of hosts and parasites interactions and highlight other possible usages. We discuss a research agenda towards a biogeographical theory of species interactions. PMID:22994257
For a client-server based view-dependent rendering system, the overhead of view-dependent rendering and the network latency are major obstacles in achieving interactivity. In this paper, we first present a multiresolution hierarchy traversal management strategy to control the overhead of view-dependent rendering for low-capacity clients. Then we propose a predictive parallel strategy to overcome the network latency for client-server based view-dependent multiresolution rendering systems. Our solution is to make the client process and the server process run in parallel, using the rendering time to cover the network latency. For networks with long round-trip times, we manage to overlap the network latency for one frame with the rendering time for multiple frames. View-parameters prediction is incorporated to make the parallelism of the client and the server feasible. In order to maintain an acceptable view-dependent rendering quality in the network environment, we develop a synchronization mechanism and a dynamic adjustment mechanism to handle the transient network slowdowns and the changes of the network condition. Our experimental results, in comparison with the sequential method, show that our predictive parallel approach can achieve an interactive frame rate while keeping an acceptable rendering quality for large triangle models over networks with relatively long round-trip times. PMID:18369265
Physical interactions between proteins mediate a variety of biological functions, including signal transduction, physical structuring of the cell and regulation. While extensive catalogs of such interactions are known from model organisms, their evolutionary histories are difficult to study given the lack of interaction data from phylogenetic outgroups. Using phylogenomic approaches, we infer a upper bound on the time of origin for a large set of human protein-protein interactions, showing that most such interactions appear relatively ancient, dating no later than the radiation of placental mammals. By analyzing paired alignments of orthologous and putatively interacting protein-coding genes from eight mammals, we find evidence for weak but significant co-evolution, as measured by relative selective constraint, between pairs of genes with interacting proteins. However, we find no strong evidence for shared instances of directional selection within an interacting pair. Finally, we use a network approach to show that the distribution of selective constraint across the protein interactionnetwork is non-random, with a clear tendency for interacting proteins to share similar selective constraints. Collectively, the results suggest that, on the whole, protein interactions in mammals are under selective constraint, presumably due to their functional roles.
Perez-Bercoff, Asa; Hudson, Corey M.; Conant, Gavin C.
Recurrent networks of polynomial threshold elements with random symmetric interactions are studied. Precise asymptotic estimates are derived for the expected number of fixed points as a function of the margin of stability. In particular, it is shown that there is a critical range of margins of stability (depending on the degree of polynomial interaction) such that the expected number of fixed points with margins below the critical range grows exponentially with the number of nodes in the network, while the expected number of fixed points with margins above the critical range decreases exponentially with the number of nodes in the network. The random energy model is also briefly examined and links with higher order neural networks and higher order spin glass models made explicit.
In the face-to-face classroom, human services counseling educators rely on highly interpersonal, interactive methods to teach clinical skills. Replicating these instructional methods in the asynchronous, text-based e-learning environment has been difficult and sometimes impossible. However, web-based technologies, specifically Web 2.0 technologies, may afford educators the opportunity to simulate and enhance the strengths of highly interpersonal and interactive methods of face-to-face
Interactive virtual worlds provide a powerful medium for entertainment and experiential learning. Our goal is to enrich such virtual worlds with virtual humans - autonomous agents that support face-to-face interac- tion with people in these environments in a variety of roles. While supporting face-to-faceinteraction in vir- tual worlds is a daunting task, this paper argues that the key building
Jeff Rickel; Jonathan Gratch; Randall Hill; Stacy Marsella; William Swartout
Determining the network of physical protein associations is an important first step in developing mechanistic evidence for elucidating biological pathways. Despite rapid advances in the field of high throughput experiments to determine protein interactions, the majority of associations remain unknown. Here we describe computational methods for significantly expanding protein association networks. We describe methods for integrating multiple independent sources of evidence to obtain higher quality predictions and we compare the major publicly available resources available for experimentalists to use. PMID:21572181
Lees, J G; Heriche, J K; Morilla, I; Ranea, J A; Orengo, C A
All pairwise interactions occurring between bases which could be detected in three-dimensional structures of crystallized RNA molecules are annotated on new planar diagrams. The diagrams attempt to map the underlying complex networks of base–base interactions and, especially, they aim at conveying key relationships between helical domains: co-axial stacking, bending and all Watson–Crick as well as non-Watson–Crick base pairs. Although such wiring diagrams cannot replace full stereographic images for correct spatial understanding and representation, they reveal structural similarities as well as the conserved patterns and distances between motifs which are present within the interactionnetworks of folded RNAs of similar or unrelated functions. Finally, the diagrams could help devising methods for meaningfully transforming RNA structures into graphs amenable to network analysis.
Using off-the-shelf hardware components and a specially developed high-end software communication system (WinVicos) satellite networks for interactive telemedicine have been designed and developed. These networks allow for various telemedical applications, like intraoperative teleconsultation, second opinioning, teleteaching, telementoring, etc.. Based on the successful GALENOS network, several projects are currently being realized: MEDASHIP (Medical Assistance for Ships); DELTASS (Disaster Emergency Logistic Telemedicine Advanced Satellites Systems) and EMISPHER (Euro-Mediterranean Internet-Satellite Platform for Health, medical Education and Research).
Graschew, Georgi; Roelofs, Theo A.; Rakowsky, Stefan; Schlag, Peter M.
Web-based hypermedia learning environments are widely used in modern education and seem particularly well suited for interdisciplinary learning. Previous work has identified guidance through these complex environments as a crucial problem of their acceptance and efficiency. We reasoned that map-based navigation might provide straightforward and effortless orientation. To achieve this, we developed a clickable and user-oriented concept map-based navigation plugin. This tool is implemented as an extension of Moodle, a widely used learning management system. It visualizes inner and interdisciplinary relations between learning objects and is generated dynamically depending on user set parameters and interactions. This plugin leaves the choice of navigation type to the user and supports direct guidance. Previously developed and evaluated face-to-face interdisciplinary learning materials bridging physiology and physics courses of a medical curriculum were integrated as learning objects, the relations of which were defined by metadata. Learning objects included text pages, self-assessments, videos, animations, and simulations. In a field study, we analyzed the effects of this learning environment on physiology and physics knowledge as well as the transfer ability of third-term medical students. Data were generated from pre- and posttest questionnaires and from tracking student navigation. Use of the hypermedia environment resulted in a significant increase of knowledge and transfer capability. Furthermore, the efficiency of learning was enhanced. We conclude that hypermedia environments based on Moodle and enriched by concept map-based navigation tools can significantly support interdisciplinary learning. Implementation of adaptivity may further strengthen this approach.
Peter M Thule (Emory University/Atlanta VA Medical Center); Kathrin Dethleffsen (Ludwig-Maximilians-UniversitÃÂ¤t); Michael Meyer (Ludwig-Maximilians-UniversitÃÂ¤t)
IL-32 has been studied for its pleiotropic effects ranging from host immune responses to cell differentiation. Although several IL-32 isoforms have been characterized for their effects on cells, the roles of the others remain unclear. We previously reported that IL-32? interacted with IL-32? and inhibited IL-32?-mediated IL-10 production. Thus, we performed comprehensive analyses to reveal more interactions between IL-32 isoforms in this study. We screened the interactions of 81 combinations of nine IL-32 isoforms by using a yeast two-hybrid assay, which identified 13 heterodimeric interactions. We verified these results by using reciprocal immunoprecipitation assays and reconfirmed 10 interactions, and presented the interactionnetwork map between IL-32 isoforms. Our data suggest that IL-32 may have diverse intracellular effects through the interactions with its different isoforms. PMID:24472437
Kang, Jeong-Woo; Park, Yun Sun; Lee, Dong Hun; Kim, Man Sub; Bak, Yesol; Ham, Sun Young; Park, Su Ho; Kim, Heejong; Ahn, Joong Hoon; Hong, Jin Tae; Yoon, Do-Young
The recent proliferation of protein interactionnetworks has motivated research into network alignment: the cross-species comparison of conserved functional modules. Previous studies have laid the foundations for such comparisons and demonstrated their power on a select set of sparse interactionnetworks. Recently, however, new computational techniques have produced hundreds of predicted interactionnetworks with interconnection densities that push existing alignment
Jason Flannick; Antal Novak; Balaji S. Srinivasan; Harley H. McAdams; Serafim Batzoglou
Over the past decade, biomedical research has witnessed an exponential increase in the throughput of the characterization of biological systems. Here we review the recent progress in large-scale methods to determine protein–protein, genetic and chemical–genetic interactionnetworks. We discuss some of the limitations and advantages of the different methods and give examples of how these networks are being used to study the evolutionary process. Comparative studies have revealed that different types of protein–protein interactions diverge at different rates with high conservation of co-complex membership but rapid divergence of more promiscuous interactions like those that mediate post-translational modifications. These evolutionary trends have consistent genetic consequences with highly conserved epistatic interactions within complex subunits but faster divergence of epistatic interactions across complexes or pathways. Finally, we discuss how these evolutionary observations are being used to interpret cross-species chemical-genetic studies and how they might shape therapeutic strategies. Together, these interactionnetworks offer us an unprecedented level of detail into how genotypes are translated to phenotypes, and we envision that they will be increasingly useful in the interpretation of genetic and phenotypic variation occurring within populations as well as the rational design of combinatorial therapeutics.
With the advent of large-scale protein interaction studies, there is much debate about data quality. Can different noise levels in the measurements be assessed by analyzing network structure? Because proteomic regulation is inherently co-operative, modular and redundant, it is inherently compressible when represented as a network. Here we propose that network compression can be used to compare false positive and false negative noise levels in protein interactionnetworks. We validate this hypothesis by first confirming the detrimental effect of false positives and false negatives. Second, we show that gold standard networks are more compressible. Third, we show that compressibility correlates with co-expression, co-localization, and shared function. Fourth, we also observe correlation with better protein tagging methods, physiological expression in contrast to over-expression of tagged proteins, and smart pooling approaches for yeast two-hybrid screens. Overall, this new measure is a proxy for both sensitivity and specificity and gives complementary information to standard measures such as average degree and clustering coefficients.
Royer, Loic; Reimann, Matthias; Stewart, A. Francis; Schroeder, Michael
The topology of the proteome map revealed by recent large-scale hybridization methods has shown that the distribution of protein–protein interactions is highly heterogeneous, with many proteins having few edges while a few of them are heavily connected. This particular topology is shared by other cellular networks, such as metabolic pathways, and it has been suggested to be responsible for the
Romualdo Pastor-Satorras; Eric Smith; Ricard V. Solé
The topology of the proteome map revealed by recent large-scale hybridization methods has shown that the distribution of protein-protein interactions is highly heterogeneous, with many proteins having few links while a few of them are heavily connected. This particular topology is shared by other cellular networks, such as metabolic pathways, and it has been suggested to be responsible for the
Romualdo Pastor-Satorras; Eric Smith; Ricard V. Solé
According to survey responses from 201 of 247 public secondary agricultural instructors, principals, and superintendents, they consider interactive video networks appropriate for high schools and are interested in inservice training. Cost is the greatest obstacle by a 3-1 margin. Instructors have more negative attitudes than principals or…
Identification and validation of interactionnetworks and network biomarkers have become more critical and important in the development of disease-specific biomarkers, which are functionally changed during disease development, progression or treatment. The present review headlined the definition, significance, research and potential application for network biomarkers, interactionnetworks and dynamical network biomarkers (DNB). Disease-specific interactionnetworks, network biomarkers, or DNB have great significance in the understanding of molecular pathogenesis, risk assessment, disease classification and monitoring, or evaluations of therapeutic responses and toxicities. Protein-based DNB will provide more information to define the differences between the normal and pre-disease stages, which might point to early diagnosis for patients. Clinical bioinformatics should be a key approach to the identification and validation of disease-specific biomarkers.
This paper describes the deployment of a large-scale study designed to measure human interactions across a variety of communication channels, with high temporal resolution and spanning multiple years—the Copenhagen Networks Study. Specifically, we collect data on face-to-faceinteractions, telecommunication, social networks, location, and background information (personality, demographics, health, politics) for a densely connected population of 1 000 individuals, using state-of-the-art smartphones as social sensors. Here we provide an overview of the related work and describe the motivation and research agenda driving the study. Additionally, the paper details the data-types measured, and the technical infrastructure in terms of both backend and phone software, as well as an outline of the deployment procedures. We document the participant privacy procedures and their underlying principles. The paper is concluded with early results from data analysis, illustrating the importance of multi-channel high-resolution approach to data collection.
This paper describes the deployment of a large-scale study designed to measure human interactions across a variety of communication channels, with high temporal resolution and spanning multiple years-the Copenhagen Networks Study. Specifically, we collect data on face-to-faceinteractions, telecommunication, social networks, location, and background information (personality, demographics, health, politics) for a densely connected population of 1 000 individuals, using state-of-the-art smartphones as social sensors. Here we provide an overview of the related work and describe the motivation and research agenda driving the study. Additionally, the paper details the data-types measured, and the technical infrastructure in terms of both backend and phone software, as well as an outline of the deployment procedures. We document the participant privacy procedures and their underlying principles. The paper is concluded with early results from data analysis, illustrating the importance of multi-channel high-resolution approach to data collection. PMID:24770359
Background Drug combination that consists of distinctive agents is an attractive strategy to combat complex diseases and has been widely used clinically with improved therapeutic effects. However, the identification of efficacious drug combinations remains a non-trivial and challenging task due to the huge number of possible combinations among the candidate drugs. As an important factor, the molecular context in which drugs exert their functions can provide crucial insights into the mechanism underlying drug combinations. Results In this work, we present a network biology approach to investigate drug combinations and their target proteins in the context of genetic interactionnetworks and the related human pathways, in order to better understand the underlying rules of effective drug combinations. Our results indicate that combinatorial drugs tend to have a smaller effect radius in the genetic interactionnetworks, which is an important parameter to describe the therapeutic effect of a drug combination from the network perspective. We also find that drug combinations are more likely to modulate functionally related pathways. Conclusions This study confirms that the molecular networks where drug combinations exert their functions can indeed provide important insights into the underlying rules of effective drug combinations. We hope that our findings can help shortcut the expedition of the future discovery of novel drug combinations.
With more dynamic information available, researchers' attention has recently shifted from static properties to dynamic properties of protein-protein interactionnetworks. To compensate the limited ability of technologies of detecting dynamic protein-protein interactions, dynamic protein interactionnetworks (DPINs) can be constructed by involving proteomic, genomic, and transcriptome analyses. Two groups of DPIN construction methods are classified based on the different focuses on dynamic information extracted from gene expression data. The dynamics of one kind of DPINs is reflected by the changes in protein presence varying with time, while that of the other kind of DPINs is reflected by the differences of coexpression under different conditions. In this review, the applications on DPINs will be discussed, including protein complexes/functional modules and network organization analysis, biomarkers detection in the progression or prognosis of the disease, and network medicine. We also point out the challenges in DPINs construction and future directions in the research of DPINs at the end of this review. PMID:24339054
\\u000a Virtual social interaction amongst seniors is strengthened through facetoface contact. While confirming previous studies\\u000a that have shown the strengthening of virtual friendships result from physical meetings, this study also showed that virtual\\u000a facetoface meetings have a similar benefit. As more seniors around the world are encouraged to stay at home longer, rather\\u000a than enter institutional care,
A microanalysis of 4-month mother-infant face-to-face communication revealed a fine-grained specification of communication processes that predicted 12-month insecure attachment outcomes, particularly resistant and disorganized classifications. An urban community sample of 84 dyads were videotaped at 4 months during a face-to-faceinteraction, and at 12 months during the Ainsworth Strange Situation. Four-month mother and infant communication modalities of attention, affect, touch,
Beatrice Beebe; Joseph Jaffe; Sara Markese; Karen Buck; Henian Chen; Patricia Cohen; Lorraine Bahrick; Howard Andrews; Stanley Feldstein
Plant-animal mutualistic networks are interaction webs consisting of two sets of entities, plant and animal species, whose evolutionary dynamics are deeply influenced by the outcomes of the interactions, yielding a diverse array of coevolutionary processes. These networks are two-mode networks sharing many common properties with others such as food webs, social, and abiotic networks. Here we describe generalized patterns in
Noncoding RNAs form unique 3D structures, which perform many regulatory functions. To understand how RNAs fold uniquely despite a small number of tertiary interaction motifs, we mutated the major tertiary interactions in a group I ribozyme by single-base substitutions. The resulting perturbations to the folding energy landscape were measured using SAXS, ribozyme activity, hydroxyl radical footprinting, and native PAGE. Double- and triple-mutant cycles show that most tertiary interactions have a small effect on the stability of the native state. Instead, the formation of core and peripheral structural motifs is cooperatively linked in near-native folding intermediates, and this cooperativity depends on the native helix orientation. The emergence of a cooperative interactionnetwork at an early stage of folding suppresses nonnative structures and guides the search for the native state. We suggest that cooperativity in noncoding RNAs arose from natural selection of architectures conducive to forming a unique, stable fold.
Behrouzi, Reza; Roh, Joon Ho; Kilburn, Duncan; Briber, R.M.; Woodson, Sarah A. (JHU); (Maryland)
SUMMARY Non-coding RNAs form unique three-dimensional structures, which perform many biochemical and regulatory functions. To understand how RNAs fold uniquely despite a small number of tertiary interaction motifs, we mutated the major tertiary interactions in a group I ribozyme. The resulting perturbations to the folding energy landscape were measured using SAXS, ribozyme activity, hydroxyl radical footprinting and native PAGE. Double and triple mutant cycles show that most tertiary interactions have a small effect on native state stability. Instead, formation of core and peripheral structural motifs are cooperatively linked in near-native folding intermediates, and this cooperativity depends on the native topology of the ribozyme. The emergence of a cooperative interactionnetwork at an early stage of folding suppresses non-native structures and makes the search for the native state more efficient. We suggest that cooperativity in non-coding RNAs arose from natural selection of architectures that promote a unique fold despite a rugged energy landscape.
Behrouzi, Reza; Roh, Joon Ho; Kilburn, Duncan; Briber, Robert M.; Woodson1, Sarah A.
An ongoing study of the structure, function, and evolution of individual activity within lab groups is introduced. This study makes extensive use of techniques from social network analysis. These techniques allow rigorous quantification and hypothesis-testing of the interactions inherent in social groups and the impact of intrinsic characteristics of individuals on their social interactions. As these techniques are novel within the physics education research community, an overview of their meaning and application is given. We then present preliminary results from videotaped laboratory groups involving mixed populations of traditional and non-traditional students in an introductory algebra-based physics course.
Multichannel data collection in the neurosciences is routine and has necessitated the development of methods to identify the direction of interactions among processes. The most widely used approach for detecting these interactions in such data is based on autoregressive models of stochastic processes, although some work has raised the possibility of serious difficulties with this approach. This article demonstrates that these difficulties are present and that they are intrinsic features of the autoregressive method. Here, we introduce a new method taking into account unobserved processes and based on coherence. Two examples of three-process networks are used to demonstrate that although coherence measures are intrinsically non-directional, a particular network configuration will be associated with a particular set of coherences. These coherences may not specify the network uniquely, but in principle will specify all network configurations consistent with their values and will also specify the relationships among the unobserved processes. Moreover, when new information becomes available, the values of the measures of association already in place do not change, but the relationships among the unobserved processes may become further resolved. PMID:21678101
New teachers need support from their peers and mentors to locate resources, information, new ideas, emotional support, and inspiration. This timely book explains the research and theory behind social networks (face-to-face and online), describes what effective social networking for educators looks like, reveals common obstacles that new teachers…
Hybrid communication networks use a combination of satellite and terrestrial communication links to optimize the system. The major advantages of closed loop hybrid interactive satellite network technology are that it reduces the response time from that experienced in systems depending solely on geosynchronous orbiting satellites and avoids the requirement of having ground stations at every node in the network. This technology uses a T1 carrier to broadcast the outbound data to the user base which provides an enormous bandwidth and footprint, and telephone multiplexed high speed data lines for inbound data which have low bandwidth but can accommodate a large number of users. The major components of this technology are as follows. The network interface unit takes multiplexed outbound data, forms it into high level data link control (HDLC) packets and superimposes it onto a T1 carrier for transmission to the satellite uplink. The packetized outbound data is transmitted to the satellite. The satellite downlink receives the data and broadcasts to ground stations anywhere in the geographic boundaries of the satellite footprint. The data is then routed to the link access unit (LAU). The LAU demultiplexes the outbound data from the downlink and routes it to the user via RS232 protocol. Inbound traffic received by the LAU is multiplexed and transmitted over high speed synchronous data lines back to the network interfaces unit and on to the host computer.
To better understand the inner workings of information spreading, network researchers often use simple models to capture the spreading dynamics. But most models only highlight the effect of local interactions on the global spreading of a single information wave, and ignore the effects of interactions between multiple waves. Here we take into account the effect of multiple interacting waves by using an agent-based model in which the interaction between information waves is based on their novelty. We analyzed the global effects of such interactions and found that information that actually reaches nodes reaches them faster. This effect is caused by selection between information waves: lagging waves die out and only leading waves survive. As a result, and in contrast to models with noninteracting information dynamics, the access to information decays with the distance from the source. Moreover, when we analyzed the model on various synthetic and real spatial road networks, we found that the decay rate also depends on the path redundancy and the effective dimension of the system. In general, the decay of the information wave frequency as a function of distance from the source follows a power-law distribution with an exponent between -0.2 for a two-dimensional system with high path redundancy and -0.5 for a tree-like system with no path redundancy. We found that the real spatial networks provide an infrastructure for information spreading that lies in between these two extremes. Finally, to better understand the mechanics behind the scaling results, we provide analytical calculations of the scaling for a one-dimensional system. PMID:24580283
Mirshahvalad, A; Esquivel, A V; Lizana, L; Rosvall, M
To better understand the inner workings of information spreading, network researchers often use simple models to capture the spreading dynamics. But most models only highlight the effect of local interactions on the global spreading of a single information wave, and ignore the effects of interactions between multiple waves. Here we take into account the effect of multiple interacting waves by using an agent-based model in which the interaction between information waves is based on their novelty. We analyzed the global effects of such interactions and found that information that actually reaches nodes reaches them faster. This effect is caused by selection between information waves: lagging waves die out and only leading waves survive. As a result, and in contrast to models with noninteracting information dynamics, the access to information decays with the distance from the source. Moreover, when we analyzed the model on various synthetic and real spatial road networks, we found that the decay rate also depends on the path redundancy and the effective dimension of the system. In general, the decay of the information wave frequency as a function of distance from the source follows a power-law distribution with an exponent between -0.2 for a two-dimensional system with high path redundancy and -0.5 for a tree-like system with no path redundancy. We found that the real spatial networks provide an infrastructure for information spreading that lies in between these two extremes. Finally, to better understand the mechanics behind the scaling results, we provide analytical calculations of the scaling for a one-dimensional system.
Mirshahvalad, A.; Esquivel, A. V.; Lizana, L.; Rosvall, M.
The two major brain networks, i.e., the default mode network (DMN) and the task positive network, typically reveal negative and variable connectivity in resting-state. In the present study, we examined whether the connectivity between the DMN and different components of the task positive network were modulated by other brain regions by using physiophysiological interaction (PPI) on resting-state functional magnetic resonance imaging data. Spatial independent component analysis was first conducted to identify components that represented networks of interest, including the anterior and posterior DMNs, salience, dorsal attention, left and right executive networks. PPI analysis was conducted between pairs of these networks to identify networks or regions that showed modulatory interactions with the two networks. Both network-wise and voxel-wise analyses revealed reciprocal positive modulatory interactions between the DMN, salience, and executive networks. Together with the anatomical properties of the salience network regions, the results suggest that the salience network may modulate the relationship between the DMN and executive networks. In addition, voxel-wise analysis demonstrated that the basal ganglia and thalamus positively interacted with the salience network and the dorsal attention network, and negatively interacted with the salience network and the DMN. The results demonstrated complex modulatory interactions among the DMNs and task positive networks in resting-state, and suggested that communications between these networks may be modulated by some critical brain structures such as the salience network, basal ganglia, and thalamus.
Considers the complete ethnographic project as a strategy for teaching qualitative methods. Describes an undergraduate class where students chose an ethnographic setting, gathered and analyzed data, and wrote a final report. Settings included Laundromats, bingo halls, auctions, karaoke clubs, and bowling leagues. (MJP)
The problem of moving the equipment of a longwall face from one (the finished) panel to the next has always been an issue critical to any longwall operation. In the United States, moving longwall equipment from panel to panel takes an average of 20 days, and moves as long as 30 days are no exception. With $8 million invested and
Verbmobil is a long-term project on the translation of spontaneous language in negotiation dialogs. We describe the goals of the project, the chosen discourse domains and the initial project schedule. We discuss some of the distinguishing features of Verbmobil and introduce the notion of translation on demand and variable depth of processing in speech translation. Finally, the role of anytime
Visual communication cues facilitate interpersonal communication. It is important that we look at faces to retrieve and subsequently process such cues. It is also important that we sometimes look away from faces as they increase cognitive load that may interfere with online processing. Indeed, when typically developing individuals hold face gaze…
Riby, Deborah M.; Doherty-Sneddon, Gwyneth; Whittle, Lisa
The information contained in the presentation covers development work carried out under SDS projects. The intent of the effort is to find chrome(VI) free alternates to our current chromated processing solutions. The information presented reports progress in work aimed to replace our alkaline cleaner (Turco 4215), conversion coat (Iridite 14-2) and chrome (VI) compounds used in LOx tank hydrostatic proof test solution. To date we have found candidates for use in the proof test solution and alkaline cleaner. These candidates are in the final stages of testing. Lab data is reported in the presentation.
In the wake of 9/11, many Muslims around the United States faced a backlash of resentment and anger. This groundswell of emotion was not without parallel, as Japanese and Japanese-Americans faced a similar reaction after the bombing of Pearl Harbor in 1941. The Independent Television Service has developed this Web site to bring a human face to the experiences of Muslims and Japanese people in the United States by collecting these powerful interviews from members of both groups. On the site, visitors can listen to stories from older Japanese-Americans talk about their experiences on the West Coast after Pearl Harbor, and the experiences of Muslims, both young and old. The interviews are divided into thematic sections, such as "Fear," "Internment," "Identity," and "Being American." At another section of the site, visitors can respond to the stories, and a glossary of terms is also provided as background material. Overall, this site serves as a fine educational tool, and for those looking for a number of perspectives on the experience of living in America.
Society for Human Resource Management (SHRM) members were surveyed to determine what advice they would give to job seekers who have disabilities. Six disability categories were used: physical, learning, auditory, visual, chronic, and “other.” Although the majority of respondents favored direct disclosure of a disability at or after the employment interview, a sizable minority recommended indirect disclosure prior to the
Linda E. Parry; Leane Rutherford; Patricia A. Merrier
One session interviews were conducted with students planning to enter the University of Illinois. The interviews dealt with interpretation of aptitude and interest tests in relation to curricular plans, discussion of the students' expected level of achievement and areas of strength and weakness, a screening procedure for personality problems and…
Neurofilaments (NFs) are a major constituent of myelinated axons of nerve cells, which assemble from three subunit proteins of low, medium, and high molecular weight to form a 10 nm diameter rod with sidearms radiating from the center. The sidearm interactions impart structural stability and result in an oriented network of NFs running parallel to the axon. Over or under expression of NF subunits is related to abnormal NF-networks, which are known hallmarks of motor neuron diseases (ALS). Here, we reassemble NFs from subunit proteins purified from bovine spinal cord. We demonstrate the formation of the NF network in vitro where synchrotron x-ray scattering (SSRL) reveals a well-defined interfilament spacing while the defect structure in polarized optical microcopy shows the liquid crystalline nature. The spacing varies depending on subunit molar ratios and salt conditions and we relate this change to the mechanical stability of the lattice. This change in lattice spacing yields insight into the stabilizing interactions between the NF sidearms. Supported by NSF DMR- 0203755, CTS-0103516, and NIH GM-59288.
A genetic interactionnetwork containing ~1000 genes and ~4000 interactions was mapped by crossing mutations in 132 different query genes into a set of ~4700 viable gene yeast deletion mutants and scoring the double mutant progeny for fitness defects. Network connectivity was predictive of function because interactions often occurred among functionally related genes, and similar patterns of interactions tended to
Amy Hin Yan Tong; Guillaume Lesage; Gary D. Bader; Huiming Ding; Hong Xu; Xiaofeng Xin; James Young; Gabriel F. Berriz; Renee L. Brost; Michael Chang; YiQun Chen; Xin Cheng; Gordon Chua; Helena Friesen; Debra S. Goldberg; Jennifer Haynes; Christine Humphries; Grace He; Shamiza Hussein; Lizhu Ke; Nevan Krogan; Zhijian Li; Joshua N. Levinson; Hong Lu; Patrice Ménard; Christella Munyana; Ainslie B. Parsons; Owen Ryan; Raffi Tonikian; Tania Roberts; Anne-Marie Sdicu; Jesse Shapiro; Bilal Sheikh; Bernhard Suter; Sharyl L. Wong; Lan V. Zhang; Hongwei Zhu; Christopher G. Burd; Sean Munro; Chris Sander; Jasper Rine; Jack Greenblatt; Matthias Peter; Anthony Bretscher; Graham Bell; Frederick P. Roth; Grant W. Brown; Brenda Andrews; Howard Bussey; Charles Boone
. This paper aims to contribute to the development of a general network theory for the social sciences. This ambition comprises\\u000a an attempt to a) formulate, and illustrate with historical examples, a general hypothesis about the relation between a contiguity\\u000a and a network principle for spatial development, and to b) use the concept of interaction costs to illuminate the genesis
The study is aimed at investigating the effects of four learning methods on students’ scientific inquiry skills. The four learning methods are: (a) metacognitive-guided inquiry within asynchronous learning networked technology (MINT); (b) an asynchronous learning network (ALN) with no metacognitive guidance; (c) metacognitive-guided inquiry embedded within face-to-face (F2F) interaction; and (d) F2F interaction with no metacognitive guidance. The study examined general scientific ability and domain-specific inquiry skills in microbiology. Participants were 407 10th-grade students (15 years old). The MINT research group significantly outperformed all other research groups, and F2F (group d) acquired the lowest mean scores. No significant differences were found between research groups (b) and (c). MINT makes significant contributions to students’ achievements in designing experiments and drawing conclusions. The novel use of metacognitive training within an ALN environment demonstrates the advantage of enhancing the effects of ALN on students’ achievements in science.
Zion, Michal; Michalsky, Tova; Mevarech, Zemira R.
In this paper, we propose a novel method for analyzing human interactions based on the walking trajectories of human subjects. Our principal assumption is that an interaction episode is composed of meaningful smaller unit interactions, which we call `sub-interactions.' The whole interaction is represented by an ordered concatenation or a network of sub-interaction models. From the experiments, we could confirm
Communication via computer networks is becoming more common each day. The differences between computer-mediated communication and face-to-face communication fall into three categories: (1) temporal factors (asynchronous versus synchronous); (2) spatial factors (geographical context and distance); and (3) social factors (participants, their…
The increasing availability of large-scale protein-protein interaction data has made it possible to understand the basic components and organization of cell machinery from the network level. The arising challenge is how to analyze such complex interacting data to reveal the principles of cellular organization, processes and functions. Many studies have shown that clustering protein interactionnetwork is an effective approach
There is an increasing demand for network analysis of protein-protein interactions (PPIs). We introduce a web-based protein interactionnetwork analysis platform (PINA), which integrates PPI data from six databases and provides network construction, filtering, analysis and visualization tools. We demonstrated the advantages of PINA by analyzing two human PPI networks; our results suggested a link between LKB1 and TGFbeta signaling, and revealed possible competitive interactors of p53 and c-Jun. PMID:19079255
Two processes can influence the evolution of protein interactionnetworks: addition and elimination of interactions between proteins, and gene duplications increasing the number of proteins and interactions. The rates of these processes can be estimated from available Saccharomyces cerevisiae genome data and are sufficiently high to affect network structure on short time-scales. For instance, more than 100 interactions may be added to the yeast network every million years, a fraction of which adds previously unconnected proteins to the network. Highly connected proteins show a greater rate of interaction turnover than proteins with few interactions. From these observations one can explain (without natural selection on global network structure) the evolutionary sustenance of the most prominent network feature, the distribution of the frequency P(d) of proteins with d neighbours, which is broad-tailed and consistent with a power law, that is: P(d) proportional, variant d (-gamma).
BACKGROUND: Protein-protein interactionnetworks are commonly sampled using yeast two hybrid approaches. However, whether topological information reaped from these experimentally-measured sub-networks can be extrapolated to complete protein-protein interactionnetworks is unclear. RESULTS: By analyzing various experimental protein-protein interaction datasets, we found that they are not random samples of the parent networks. Based on the experimental bait-prey behaviors, our computer simulations
Ling Yang; Thomas M. Vondriska; Zhangang Han; W. Robb Maclellan; James N. Weiss; Zhilin Qu
Protein-protein interactionnetworks provide a global picture of cellular function and biological processes. Some proteins act as hub proteins, highly connected to others, whereas some others have few interactions. The dysfunction of some interactions causes many diseases, including cancer. Proteins interact through their interfaces. Therefore, studying the interface properties of cancer-related proteins will help explain their role in the interaction
Naturally occurring networks exhibit quantitative features revealing underly- ing growth mechanisms. Numerous network mechanisms have recently been proposed to reproduce specific properties such as degree distributions or clus- tering coefficients. We present a method for inferring the mechanism most accurately capturing a given network topology, exploiting discriminative tools from machine learning. The Drosophila melanogaster protein network is con- fidently and
The development of organic molecules as active components of electronic and optoelectronic devices has seen unprecedented progress in the past decade. This attention is primarily due to the potential impact on large-area and low-cost fabrication of devices, integrated circuits, flexible displays, and in particular, organic field-effect transistors (OFETs). Organic semiconductors that pack face-to-face in the solid state are of particular interest since they are known to self-assemble into 1-D nanostructures due to strong pi-pi interactions. Engineering linear/planar molecules to pack face-to-face is challenging because the interacting forces between organic molecules are relatively weak. Three approaches were used to induce face-to-face packing in organic semiconductors: (1) several derivatives of hexaazatrinaphthylene, (HATNA), were designed which vary in their degree of hydrogen bonding, rigidity, and electron deficiency. Hydrogen bonded moieties induced strong interaction between cores that formed robust nanowires when subjected to nonpolar solvents. While no device data was measured for these materials, substituents location was found to have a profound effect on the electronic properties; (2) Inspired by S···S interactions found in tetrathiafulvalene (TTF) and electrostatic interactions found in 1,2,5-thiadiazole derivatives, a hybrid of these two molecules was developed (BT-TTF-1). Short intermolecular S···S, S···N, and S···C contacts define the solid state structure of BT-TTF-1 single crystals which pi-stack along the . Theoretical insight into the nature of the interactions revealed that the close contacts are electrostatic in origin rather than the result of London dispersion forces. Thermal evaporation yields a network of poorly connected crystals which significantly limits the mobility. Solvent-cast single-crystal nanowire transistors showed mobilities as large as 0.36 cm2/Vs with excellent device characteristics underscoring the applicability of solvent-dispersed crystals for high-performance transistor devices; (3) 1,2,5-thiadiazole modified linear acenes, which varied in polarizable heteroatoms in the fused ring system were designed and synthesized. Short thiadiazole contacts were also observed in these molecules and though energy levels were similar, only linear diazaacenes showed reduction potentials in an electrochemical cell.
Presents S. Jackson's and S. Jacobs' theory of conversational argument and demonstrates flaws in the representational validity of their research from the perspective of face-to-faceinteraction. Describes characteristics of a "paradigm case" of interactional argument that extends Jackson's and Jacobs' ideas about argumentation in ordinary…
Virtual Space Teleconferencing System (VST), which based on video teleconferencing system, is a combination of Virtual Reality and several other techniques, such as Network Communication and Natural Language Processing. Participants appear in computer-generated virtual spaces as avatars in VST, and these avatars can locate, view, manipulate virtual objects, communicate with others facetoface, so participants could share 'the same space' and do cooperative work. When participants use different kinds of natural language to communicate, language barrier would arise in interaction. So, besides the basic natural language processing, VST should provide translation service based on Machine Translation. First, this paper introduces the features of VST. Second, it describes the techniques of English-Chinese Bi-directional Machine Translation. Third, it analyzes the special requirements of English-Chinese bilingual interaction environment in VST. Finally it discusses the key issues of English-Chinese bilingual interaction environment and proposes a method of construction.
The kidney is one of the major organs involved in whole-body homeostasis, and exhibits many of the properties of a complex system. The functional unit of the kidney is the nephron, a complex, segmented tube into which blood plasma is filtered and its composition adjusted. Although the behaviour of individual nephrons can fluctuate widely and even chaotically, the behaviour of the kidney remains stable. In this paper, we investigate how the filtration rate of a multi-nephron system is affected by interactions between nephrons. We introduce a discrete-time multi-nephron network model. The tubular mechanisms that have the greatest effect on filtration rate are the transport of sodium and water, consequently our model attempts to capture these mechanisms. Multi-nephron systems also incorporate two competing coupling mechanisms-vascular and hemodynamic-that enforce in-phase and anti-phase synchronisations respectively. Using a two-nephron model, we demonstrate how changing the strength of the hemodynamic coupling mechanism and changing the arterial blood pressure have equivalent effects on the system. The same two-nephron system is then used to demonstrate the interactions that arise between the two coupling mechanisms. We conclude by arguing that our approach is scalable to large numbers of nephrons, based on the performance characteristics of the model.
Moss, Rob; Kazmierczak, Ed; Kirley, Michael; Harris, Peter
Recent advances in techniques such as NMR and EPR spectroscopy have enabled the elucidation of how proteins undergo structural changes to act in concert in complex networks. The three minireviews in this series highlight current findings and the capabilities of new methodologies for unraveling the dynamic changes controlling diverse cellular functions. They represent a sampling of the cutting-edge research presented at the 17th Meeting of Methods in Protein Structure Analysis, MPSA2008, in Sapporo, Japan, 26-29 August, 2008 (http://www.iapsap.bnl.gov). The first minireview, by Christensen and Klevit, reports on a structure-based yeast two-hybrid method for identifying E2 ubiquitin-conjugating enzymes that interact with the E3 BRCA1/BARD1 heterodimer ligase to generate either mono- or polyubiquitinated products. This method demonstrated for the first time that the BRCA1/BARD1 E3 can interact with 10 different E2 enzymes. Interestingly, the interaction with multiple E2 enzymes displayed unique ubiquitin-transfer properties, a feature expected to be common among other RING and U-box E3s. Further characterization of new E3 ligases and the E2 enzymes that interact with them will greatly enhance our understanding of ubiquitin transfer and facilitate studies of roles of ubiquitin and ubiquitin-like proteins in protein processing and trafficking. Stein et al., in the second minireview, describe recent progress in defining the binding specificity of different peptide-binding domains. The authors clearly point out that transient peptide interactions mediated by both post-translational modifications and disordered regions ensure a high level of specificity. They postulate that a regulatory code may dictate the number of combinations of domains and post-translational modifications needed to achieve the required level of interaction specificity. Moreover, recognition alone is not enough to obtain a stable complex, especially in a complex cellular environment. Increasing evidence indicates that disordered domains can acquire structural features that modulate the binding and strength of the signaling cascade. Whereas the first two minireviews describe ways in which protein interactions are modulated, the third, by Tompa, focuses on the importance of protein disorder in a subset of amyloid proteins. It is apparent that within this group, part of the polypeptide chain remains disordered during amyloid formation. Moreover, the disordered segments have different amino acid composition and physicochemical characteristics, which suggests that they may play a role in amyloid stability. The disordered region may serve as a linker to connect the ordered core and a globular domain, maintaining the stability and structure of the globular domain and minimizing protein refolding upon amyloid formation. As techniques in protein chemistry advance, we are learning more and more about the mechanisms that regulate and are regulated by protein interactions. The three minireviews in this series offer a glimpse of the complex dynamics fundamental to protein-protein interactions. In the future, we expect that the knowledge gained will help to augment our ability to control complex pathologies and treat diverse diseases states.
Background In systems biology, comparative analyses of molecular interactions across diverse species indicate that conservation and divergence of networks can be used to understand functional evolution from a systems perspective. A key characteristic of these networks is their modularity, which contributes significantly to their robustness, as well as adaptability. Consequently, analysis of modular network structures from a phylogenetic perspective may be useful in understanding the emergence, conservation, and diversification of functional modularity. Results In this paper, we propose a phylogenetic framework for analyzing network modules, with applications that extend well beyond network-based phylogeny reconstruction. Our approach is based on identification of modular network components from each network separately, followed by projection of these modules onto the networks of other species to compare different networks. Subsequently, we use the conservation of various modules in each network to assess the similarity between different networks. Compared to traditional methods that rely on topological comparisons, our approach has key advantages in (i) avoiding intractable graph comparison problems in comparative network analysis, (ii) accounting for noise and missing data through flexible treatment of network conservation, and (iii) providing insights on the evolution of biological systems through investigation of the evolutionary trajectories of network modules. We test our method, MOPHY, on synthetic data generated by simulation of network evolution, as well as existing protein-protein interaction data for seven diverse species. Comprehensive experimental results show that MOPHY is promising in reconstructing evolutionary histories of extant networks based on conservation of modularity, it is highly robust to noise, and outperforms existing methods that quantify network similarity in terms of conservation of network topology. Conclusion These results establish modularity and network proximity as useful features in comparative network analysis and motivate detailed studies of the evolutionary histories of network modules.
Erten, Sinan; Li, Xin; Bebek, Gurkan; Li, Jing; Koyuturk, Mehmet
Wireless Network Interface Cards (WNICs) are part of every portable device, where ecient energy management plays a significant role in extending the device's battery life. The goal of ecient energy management is to match the perfor- mance of the WNIC to the network activity shaped by a running application. In the case of interactive applications on mobile systems, network I\\/O
Wireless Network Interface Cards (WNICs) are part of every portable device, where efficient energy management plays a significant role in extending the device's battery life. The goal of efficient energy management is to match the performance of the WNIC to the network activity shaped by a running application. In the case of interactive applications on mobile systems, network I\\/O is
The rise of the network economy brought about the strong conviction that economic interactions in the network economy could be based on cooperative, informed and transparent communication, which would counteract the negative welfare effects of unequal bargaining power, the opacity of the intentions of the parties, opportunistic behaviors, monopolies and market failures. So the contracts of the network economy nowadays
BACKGROUND: In systems biology, comparative analyses of molecular interactions across diverse species indicate that conservation and divergence of networks can be used to understand functional evolution from a systems perspective. A key characteristic of these networks is their modularity, which contributes significantly to their robustness, as well as adaptability. Consequently, analysis of modular network structures from a phylogenetic perspective may
Sinan Erten; Xin Li; Gürkan Bebek; Jing Li; Mehmet Koyutürk
From the spectral plot of the (normalized) graph Laplacian, the essential qualitative properties of a network can be simultaneously deduced. Given a class of empirical networks, reconstruction schemes for elucidating the evolutionary dynamics leading to those particular data can then be developed. This method is exemplified for protein-protein interactionnetworks. Traces of their evolutionary history of duplication and divergence processes
The recent availability of high-throughput gene expression and proteomics techniques has created an unprecedented opportunity for a comprehensive study of the structure and dynamics of many biological networks. Global proteomic interaction data, in particular, are synthetically represented as undirected networks exhibiting features far from the random paradigm which has dominated past effort in network theory. This evidence, along with the
Vittoria Colizza; Alessandro Flammini; Amos Maritan; Alessandro Vespignani
While psychologists analyze network game-playing behavior in terms of players' social interaction and experience, un- derstanding user behavior is equally important to network researchers, because how users act determines how well net- work systems, such as online games, perform. To gain a bet- ter understanding of patterns of player interaction and their implications for game design, we analyze a 1,
Interactions among units in complex systems occur in a specific sequential order, thus affecting the flow of information, the propagation of diseases, and general dynamical processes. We investigate the Laplacian spectrum of temporal networks and compare it with that of the corresponding aggregate network. First, we show that the spectrum of the ensemble average of a temporal network has identical eigenmodes but smaller eigenvalues than the aggregate networks. In large networks without edge condensation, the expected temporal dynamics is a time-rescaled version of the aggregate dynamics. Even for single sequential realizations, diffusive dynamics is slower in temporal networks. These discrepancies are due to the noncommutability of interactions. We illustrate our analytical findings using a simple temporal motif, larger network models, and real temporal networks.
Masuda, Naoki; Klemm, Konstantin; Eguíluz, Víctor M.
Interactions among units in complex systems occur in a specific sequential order, thus affecting the flow of information, the propagation of diseases, and general dynamical processes. We investigate the Laplacian spectrum of temporal networks and compare it with that of the corresponding aggregate network. First, we show that the spectrum of the ensemble average of a temporal network has identical eigenmodes but smaller eigenvalues than the aggregate networks. In large networks without edge condensation, the expected temporal dynamics is a time-rescaled version of the aggregate dynamics. Even for single sequential realizations, diffusive dynamics is slower in temporal networks. These discrepancies are due to the noncommutability of interactions. We illustrate our analytical findings using a simple temporal motif, larger network models, and real temporal networks. PMID:24237569
Masuda, Naoki; Klemm, Konstantin; Eguíluz, Víctor M
\\u000a Recently, interacting neural network has been studied out coming a novel result that the two neural networks can synchronize\\u000a to a stationary weight state with the same initial inputs. In this paper, a simple but novel interacting neural network based\\u000a authentication scheme is proposed, which can provide a full dynamic and security remote user authentication over a completely\\u000a insecure communication
We study a modified version of a model previously proposed by Jackson and Wolinsky to account for communication of information and allocation of goods in socioeconomic networks. In the model, the utility function of each node is given by a weighted sum of contributions from all accessible nodes. The weights, parametrized by the variable ? , decrease with distance. We introduce a growth mechanism where new nodes attach to the existing network preferentially by utility. By increasing ? , the network structure evolves from a power-law to an exponential degree distribution, passing through a regime characterized by shorter average path length, lower degree assortativity, and higher central point dominance. In the second part of the paper we compare different network structures in terms of the average utility received by each node. We show that power-law networks provide higher average utility than Poisson random networks. This provides a possible justification for the ubiquitousness of scale-free networks in the real world.
Background Details of the mechanisms and selection pressures that shape the emergence and development of complex biological systems, such as the human immune system, are poorly understood. A recent definition of a reference set of proteins essential for the human immunome, combined with information about protein interactionnetworks for these proteins, facilitates evolutionary study of this biological machinery. Results Here, we present a detailed study of the development of the immunome protein interactionnetwork during eight evolutionary steps from Bilateria ancestors to human. New nodes show preferential attachment to high degree proteins. The efficiency of the immunome protein interactionnetwork increases during the evolutionary steps, whereas the vulnerability of the network decreases. Conclusion Our results shed light on selective forces acting on the emergence of biological networks. It is likely that the high efficiency and low vulnerability are intrinsic properties of many biological networks, which arise from the effects of evolutionary processes yet to be uncovered.
Protein-protein interaction (PPI) networks carry vital information on the organization of molecular interactions in cellular systems. The identification of functionally relevant modules in PPI networks is one of the most important applications of biological network analysis. Computational analysis is becoming an indispensable tool to understand large-scale biomolecular interactionnetworks. Several types of computational methods have been developed and employed for the analysis of PPI networks. Of these computational methods, graph comparison and module detection are the two most commonly used strategies. This review summarizes current literature on graph kernel and graph alignment methods for graph comparison strategies, as well as module detection approaches including seed-and-extend, hierarchical clustering, optimization-based, probabilistic, and frequent subgraph methods. Herein, we provide a comprehensive review of the major algorithms employed under each theme, including our recently published frequent subgraph method, for detecting functional modules commonly shared across multiple cancer PPI networks.
Interactions between proteins are essential for intracellular communication. They form complex networks which have become an important source for functional analysis of proteins. Combining phylogenies with network analysis, we investigate the evolutionary history of interactionnetworks from the bHLH, NR and bZIP transcription-factor families. The bHLH and NR networks show a hub-like structure with varying ? values. Mutation and gene duplication play an important role in adding and removing interactions. We conclude that in several of the protein families that we have studied, networks have primarily arisen by the development of heterodimerizing transcription factors, from an ancestral gene which interacts with any of the newly emerging proteins but also homodimerizes.
In this paper, we consider a pair of homogeneous diseases spreading concurrently on uniform networks based on the SIS model. A new model describing the transmission process of the interacting diseases is established. The influence of the transmission parameters, the interacting parameter and the initial density value of infected nodes on the epidemic spreading is presented by simulating the transmission process of the proposed model. The mathematical expressions of the conditions among the transmission parameters, the interacting parameter and the network parameter when diseases can exist in the network based on the simplified model are presented. Comparing the transmission process of this interacting model under different intervals of the interacting parameter, it is found that the interacting of the two diseases leads to larger scale prevalence with a relatively larger interacting parameter when the infection breaks out.
Quantitative analysis of tandem-affinity purified cross-linked (x) protein complexes (QTAX) is a powerful technique for the identification of protein interactions, including weak and/or transient components. Here, we apply a QTAX-based tag-team mass spectrometry strategy coupled with protein network analysis to acquire a comprehensive and detailed assessment of the protein interactionnetwork of the yeast 26S proteasome. We have determined that the proteasome network is composed of at least 471 proteins, significantly more than the total number of proteins identified by previous reports using proteasome subunits as baits. Validation of the selected proteasome-interacting proteins by reverse copurification and immunoblotting experiments with and without cross-linking, further demonstrates the power of the QTAX strategy for capturing protein interactions of all natures. In addition, >80% of the identified interactions have been confirmed by existing data using protein network analysis. Moreover, evidence obtained through network analysis links the proteasome to protein complexes associated with diverse cellular functions. This work presents the most complete analysis of the proteasome interactionnetwork to date, providing an inclusive set of physical interaction data consistent with physiological roles for the proteasome that have been suggested primarily through genetic analyses. Moreover, the methodology described here is a general proteomic tool for the comprehensive study of protein interactionnetworks.
Guerrero, Cortnie; Milenkovic, Tijana; Przulj, Natasa; Kaiser, Peter; Huang, Lan
Oscillations in electrical activity are a characteristic feature of many brain networks and display a wide variety of temporal patterns. A network may express a single oscillation frequency, alternate between two or more distinct frequencies, or continually express multiple frequencies. In addition, oscillation amplitude may fluctuate over time. The origin of this complex repertoire of activity remains unclear. Different cortical layers often produce distinct oscillation frequencies. To investigate whether interactions between different networks could contribute to the variety of oscillation patterns, we created two model networks, one generating on its own a relatively slow frequency (20 Hz; slow network) and one generating a fast frequency (32 Hz; fast network). Taking either the slow or the fast network as source network projecting connections to the other, or target, network, we systematically investigated how type and strength of inter-network connections affected target network activity. For high inter-network connection strengths, we found that the slow network was more effective at completely imposing its rhythm on the fast network than the other way around. The strongest entrainment occurred when excitatory cells of the slow network projected to excitatory or inhibitory cells of the fast network. The fast network most strongly imposed its rhythm on the slow network when its excitatory cells projected to excitatory cells of the slow network. Interestingly, for lower inter-network connection strengths, multiple frequencies coexisted in the target network. Just as observed in rat prefrontal cortex, the target network could express multiple frequencies at the same time, alternate between two distinct oscillation frequencies, or express a single frequency with alternating episodes of high and low amplitude. Together, our results suggest that input from other oscillating networks may markedly alter a network's frequency spectrum and may partly be responsible for the rich repertoire of temporal oscillation patterns observed in the brain.
Avella Gonzalez, Oscar J.; van Aerde, Karlijn I.; Mansvelder, Huibert D.; van Pelt, Jaap; van Ooyen, Arjen
The objective of English for Elite Police Network program is to provide an interactive platform for trainees, instructors, police experts and other participants so as to enhance interests as well as efficiency in professional English learning and training. Computer-mediated interactions are strengthened in both police English learning and policing skills training through role-playing, discussing and interacting in scenarios which enable
Purpose – The purpose of this paper is to analyse the interactions that are engaged in when specialist organizations collaborate in business networks organized around global value chains. Interaction costs are defined as including transaction costs plus the costs for exchanging information and ideas. The view is forwarded that as interaction costs decrease, potential business partners have greater scope to
David Walters; Jyotirmoyee Bhattacharjya; Judith Chapman
BACKGROUND: Protein interactions are crucial components of all cellular processes. Recently, high-throughput methods have been developed to obtain a global description of the interactome (the whole network of protein interactions for a given organism). In 2002, the yeast interactome was estimated to contain up to 80,000 potential interactions. This estimate is based on the integration of data sets obtained by
The relationship between stability and biodiversity has long been debated in ecology due to opposing empirical observations and theoretical predictions. Species interaction strength is often assumed to be monotonically related to population density, but the effects on stability of ecological networks of non-monotonous interactions that change signs have not been investigated previously. We demonstrate that for four kinds of non-monotonous interactions, shifting signs to negative or neutral interactions at high population density increases persistence (a measure of stability) of ecological networks, while for the other two kinds of non-monotonous interactions shifting signs to positive interactions at high population density decreases persistence of networks. Our results reveal a novel mechanism of network stabilization caused by specific non-monotonous interaction types through either increasing stable equilibrium points or reducing unstable equilibrium points (or both). These specific non-monotonous interactions may be important in maintaining stable and complex ecological networks, as well as other networks such as genes, neurons, the internet and human societies. PMID:24478300
The capacity to resist perturbations from the environment is crucial to the survival of all organisms. We quantitatively analyze the susceptibility of protein interactionnetworks of numerous organisms to random and targeted failures. We find for all organisms studied that random rewiring improves protein network robustness, so that actual networks are more fragile than rewired surrogates. This unexpected fragility contrasts with the behavior of networks such as the Internet, whose robustness decreases with random rewiring. We trace this surprising effect to the modular structure of protein networks.
Schneider, C. M.; Andrade, R. F. S.; Shinbrot, T.; Herrmann, H. J.
In drug discovery, promiscuous targets, multifactorial diseases, and “dirty” drugs construct complex network relationships. Network pharmacology description and analysis not only give a systems-level understanding of drug action and disease complexity but can also help to improve the efficiency of target selection and drug design. Visual network pharmacology (VNP) is developed to visualize network pharmacology of targets, diseases, and drugs with a graph network by using disease, target or drug names, chemical structures, or protein sequence. To our knowledge, VNP is the first free interactive VNP server that should be very helpful for systems pharmacology research. VNP is freely available at http://cadd.whu.edu.cn/ditad/vnpsearch.
E. Husserl's concept of intentionality provides a conceptual perspective of interpersonal communication that suggests a notion of face-to-face communication called "interaction involvement." Structured along dimensions of awareness and responsiveness, interaction involvement explains interpersonal communication as a transactional relationship…
This study describes a novel interactive platform for faculty development, particularly focusing on transmitting some subtle teaching experiences, e.g., interaction with students inside and outside of class, facetoface and via the Internet. This work examined two outstanding instructional faculties at the National Central University, including…
In GALENOS (Generic Advanced Low-cost trans-European Network Over Satellite) a trans-European competence network via satellite, dedicated to telemedical applications, has been realized. Using off-the-shelf hardware components and a specially developed high-end software communication system (WinVicos) various telemedical applications, like teleteaching, intraoperative teleconsultation, have been realized.
Graschew, Georgi; Roelofs, Theo A.; Rakowsky, Stefan; Schlag, Peter M.
Arguing that electronic networking provides a medium which is qualitatively superior to the traditional classroom for conducting certain types of problem solving exercises, this paper details the Water Problem Solving Project, which was conducted on the InterCultural Learning Network in 1985 and 1986 with students from the United States, Mexico,…
Identifying essential proteins is important for understanding the minimal requirements for cellular survival and development. Fast growth in the amount of available protein-protein interactions has produced unprecedented opportunities for detecting protein essentiality on network level. A series of centrality measures have been proposed to discover essential proteins based on network topology. However, most of them treat all interactions equally and are sensitive to false positives. In this paper, six standard centrality measures are redefined to be used in weighted network. A new method for weighing protein-protein interactions is proposed based on the combination of logistic regression-based model and function similarity. The experimental results on yeast network show that the weighting method can improve the performance of centrality measures considerably. More essential proteins are discovered by the weighted centrality measures than by the original centrality measures used in unweighted network. Even about 20% improvements are obtained from closeness centrality and subgraph centrality.
We study pair correlations in interacting systems placed on complex networks. We show that usually in these systems, pair correlations between interacting objects (e.g., spins), separated by a distance ? , decay, on average, faster than 1/(?z?) . Here z? is the mean number of the ? th nearest neighbors of a vertex in a network. This behavior, in particular, leads to a dramatic weakening of correlations between second and more distant neighbors on networks with fat-tailed degree distributions, which have a divergent number z2 in the infinite network limit. In large networks of this kind, only pair correlations between the nearest neighbors are actually observable. We find the pair correlation function of the Ising model on a complex network. This exact result is confirmed by a phenomenological approach.
Dorogovtsev, S. N.; Goltsev, A. V.; Mendes, J. F. F.
Protein–protein interactions form the basis for a vast majority of cellular events, including signal transduction and transcriptional regulation. It is now understood that the study of interactions between cellular macromolecules is fundamental to the understanding of biological systems. Interactions between proteins have been studied through a number of high-throughput experiments and have also been predicted through an array of computational methods that leverage the vast amount of sequence data generated in the last decade. In this review, I discuss some of the important computational methods for the prediction of functional linkages between proteins. I then give a brief overview of some of the databases and tools that are useful for a study of protein–protein interactions. I also present an introduction to network theory, followed by a discussion of the parameters commonly used in analysing networks, important network topologies, as well as methods to identify important network components, based on perturbations.
BACKGROUND: Recently, revealing the function of proteins with protein-protein interaction (PPI) networks is regarded as one of important issues in bioinformatics. With the development of experimental methods such as the yeast two-hybrid method, the data of protein interaction have been increasing extremely. Many databases dealing with these data comprehensively have been constructed and applied to analyzing PPI networks. However, few
We represent proteins by amino acid interactionnetworks. This is a graph whose vertices are the proteins amino acids and whose edges are the interactions between them. Once we have compared this type of graphs to the general model of scale-free networks, we analyze the existence of nodes which highly interact, the hubs. We describe these nodes taking into account their position in the primary structure to study their apparition frequency in the folded proteins. Finally, we observe that their interaction level is a consequence of the general rules which govern the folding process.
The IRIS Network of Excellence started its work in January 2009. In this paper we highlight some new research directions developing within the network: one is revisiting narrative formalisation through the use of Linear Logic and the other is challenging the conventional framework of basing Interactive Storytelling on computer graphics to explore the content-based recombination of video sequences.
This paper deals with the design of a Modbus Enabled Zigbee Wireless Sensor Network “WSN” for better Interactive Industrial Automation. The Modbus protocol is embedded into Zigbee stack, providing a friendly interface to observe the information in the wireless network efficiently and to provide the On Demand Response to the requests. It consists of a Coordinator and the sensor nodes.
The original publication is available from www.springerlink.com.\\u000aBerlanga, A., Rusman, E., Bitter-Rijpkema, M., & Sloep, P. B. (2009). Guidelines to foster interaction in online communities for Learning Networks. In R. Koper (Ed.), Learning Network Services for Professional Development (pp. 27-42). Berlin, Germany: Springer Verlag.
Adriana Berlanga; Ellen Rusman; Marlies Bitter-Rijpkema; Peter Sloep
We identify a relation between the dynamics of ultracold Rydberg gases in which atoms experience a strong dipole blockade and spontaneous emission, and a stochastic process that models certain wireless random-access networks. We then transfer insights and techniques initially developed for these wireless networks to the realm of Rydberg gases, and explain how the Rydberg gas can be driven into crystal formations using our understanding of wireless networks. Finally, we propose a method to determine Rabi frequencies (laser intensities) such that particles in the Rydberg gas are excited with specified target excitation probabilities, providing control over mixed-state populations.
Sanders, Jaron; van Bijnen, Rick; Vredenbregt, Edgar; Kokkelmans, Servaas
We identify a relation between the dynamics of ultracold Rydberg gases in which atoms experience a strong dipole blockade and spontaneous emission, and a stochastic process that models certain wireless random-access networks. We then transfer insights and techniques initially developed for these wireless networks to the realm of Rydberg gases, and explain how the Rydberg gas can be driven into crystal formations using our understanding of wireless networks. Finally, we propose a method to determine Rabi frequencies (laser intensities) such that particles in the Rydberg gas are excited with specified target excitation probabilities, providing control over mixed-state populations. PMID:24815645
Sanders, Jaron; van Bijnen, Rick; Vredenbregt, Edgar; Kokkelmans, Servaas
Background Protein complexes can be identified from the protein interactionnetworks derived from experimental data sets. However, these analyses are challenging because of the presence of unreliable interactions and the complex connectivity of the network. The integration of protein-protein interactions with the data from other sources can be leveraged for improving the effectiveness of protein complexes detection algorithms. Methods We have developed novel semantic similarity method, which use Gene Ontology (GO) annotations to measure the reliability of protein-protein interactions. The protein interactionnetworks can be converted into a weighted graph representation by assigning the reliability values to each interaction as a weight. Following the approach of that of the previously proposed clustering algorithm IPCA which expands clusters starting from seeded vertices, we present a clustering algorithm OIIP based on the new weighted Protein-Protein interactionnetworks for identifying protein complexes. Results The algorithm OIIP is applied to the protein interactionnetwork of Sacchromyces cerevisiae and identifies many well known complexes. Experimental results show that the algorithm OIIP has higher F-measure and accuracy compared to other competing approaches.
Analysis of gene interactionnetworks is crucial for understanding fundamental cellular processes involving growth, development,\\u000a hormone secretion and cellular communication.A gene interactionnetwork comprises of proteins and genes binding to each other,\\u000a and acting as a complex input-output system for controlling cellular functions. A small set of genes take part in a cellular\\u000a process of interest, while a single gene
The scale free structure p(k) ~ k-? of protein-protein interactionnetworks can be reproduced by a static physical model in simulation. We inspect the model theoretically, and find the key reason for the model generating apparent scale free degree distributions. This explanation provides a generic mechanism of 'scale free' networks. Moreover, we predict the dependence of ? on experimental protein concentrations or other sensitivity factors in detecting interactions, and find experimental evidence to support the prediction.
Understanding complex networks of protein-protein interactions (PPIs) is one of the foremost challenges of the post-genomic era. Due to the recent advances in experimental bio-technology including yeast-2- hybrid (Y2H), tandem affinity purification (TAP) and other high-throughput methods for protein-protein interaction (PPI) detection, huge amounts of PPI network data are becoming available. Of major concern, however, are the levels of noise
Oleksii Kuchaiev; Marija Raÿsajski; Desmond J. Higham; Nataša Pržulj
Understanding complex networks of protein-protein interactions (PPIs) is one of the foremost challenges of the post-genomic era. Due to the recent advances in experimental bio-technology, including yeast-2-hybrid (Y2H), tandem affinity purification (TAP) and other high-throughput methods for protein-protein interaction (PPI) detection, huge amounts of PPI network data are becoming available. Of major concern, however, are the levels of noise and
Oleksii Kuchaiev; Marija Rašajski; Desmond J. Higham; Nataša Pržulj
Biological network analysis is a powerful approach to gain systems-level understanding of patterns of gene expression in different cell types, disease states and other biological/experimental conditions. Three consecutive steps are required - identification of genes or proteins of interest, network construction and network analysis and visualization. To date, researchers have to learn to use a combination of several tools to accomplish this task. In addition, interactive visualization of large networks has been primarily restricted to locally installed programs. To address these challenges, we have developed NetworkAnalyst, taking advantage of state-of-the-art web technologies, to enable high performance network analysis with rich user experience. NetworkAnalyst integrates all three steps and presents the results via a powerful online network visualization framework. Users can upload gene or protein lists, single or multiple gene expression datasets to perform comprehensive gene annotation and differential expression analysis. Significant genes are mapped to our manually curated protein-protein interaction database to construct relevant networks. The results are presented through standard web browsers for network analysis and interactive exploration. NetworkAnalyst supports common functions for network topology and module analyses. Users can easily search, zoom and highlight nodes or modules, as well as perform functional enrichment analysis on these selections. The networks can be customized with different layouts, colors or node sizes, and exported as PNG, PDF or GraphML files. Comprehensive FAQs, tutorials and context-based tips and instructions are provided. NetworkAnalyst currently supports protein-protein interactionnetwork analysis for human and mouse and is freely available at http://www.networkanalyst.ca. PMID:24861621
Background The recently emerged protein interactionnetwork paradigm can provide novel and important insights into the innerworkings of a cell. Yet, the heavy burden of both false positive and false negative protein-protein interaction data casts doubt on the broader usefulness of these interaction sets. Approaches focusing on one-protein-at-a-time have been powerfully employed to demonstrate the high degree of conservation of proteins participating in numerous interactions; here, we expand his 'node' focused paradigm to investigate the relative persistence of 'link' based evolutionary signals in a protein interactionnetwork of S. cerevisiae and point out the value of this relatively untapped source of information. Results The trend for highly connected proteins to be preferably conserved in evolution is stable, even in the context of tremendous noise in the underlying protein interactions as well as in the assignment of orthology among five higher eukaryotes. We find that local clustering around interactions correlates with preferred evolutionary conservation of the participating proteins; furthermore the correlation between high local clustering and evolutionary conservation is accompanied by a stable elevated degree of coexpression of the interacting proteins. We use this conserved interaction data, combined with P. falciparum /Yeast orthologs, as proof-of-principle that high-order network topology can be used comparatively to deduce local network structure in non-model organisms. Conclusion High local clustering is a criterion for the reliability of an interaction and coincides with preferred evolutionary conservation and significant coexpression. These strong and stable correlations indicate that evolutionary units go beyond a single protein to include the interactions among them. In particular, the stability of these signals in the face of extreme noise suggests that empirical protein interaction data can be integrated with orthologous clustering around these protein interactions to reliably infer local network structures in non-model organisms.
Wuchty, Stefan; Barabasi, Albert-Laszlo; Ferdig, Michael T
Neural network ensemble (NNE) has been shown to outperform single neural network (NN) in terms of generalization ability.\\u000a The performance of NNE is therefore depends on well diversity among component NNs. Popular NNE methods, such as bagging and\\u000a boosting, follow data sampling technique to achieve diversity. In such methods, NN is trained independently with a particular\\u000a training set that is
A substantial proportion of protein interactions relies on small domains binding to short peptides in the partner proteins. Many of these interactions are relatively low affinity and transient, and they impact on signal transduction. However, neither the number of potential interactions mediated by each domain nor the degree of promiscuity at a whole proteome level has been investigated. We have
Interactive tabletops are gaining increased attention from CSCL researchers. This paper analyses the relation between this\\u000a technology and teaching and learning processes. At a global level, one could argue that tabletops convey a socio-constructivist\\u000a flavor: they support small teams that solve problems by exploring multiple solutions. The development of tabletop applications\\u000a also witnesses the growing importance of face-to-face collaboration in
Background Interaction between proteins is one of the most important mechanisms in the execution of cellular functions. The study of these interactions has provided insight into the functioning of an organism’s processes. As of October 2013, Homo sapiens had over 170000 Protein-Protein interactions (PPI) registered in the Interologous Interaction Database, which is only one of the many public resources where protein interactions can be accessed. These numbers exemplify the volume of data that research on the topic has generated. Visualization of large data sets is a well known strategy to make sense of information, and protein interaction data is no exception. There are several tools that allow the exploration of this data, providing different methods to visualize protein networkinteractions. However, there is still no native web tool that allows this data to be explored interactively online. Results Given the advances that web technologies have made recently it is time to bring these interactive views to the web to provide an easily accessible forum to visualize PPI. We have created a Web-based Protein InteractionNetwork Visualizer: PINV, an open source, native web application that facilitates the visualization of protein interactions (http://biosual.cbio.uct.ac.za/pinv.html). We developed PINV as a set of components that follow the protocol defined in BioJS and use the D3 library to create the graphic layouts. We demonstrate the use of PINV with multi-organism interactionnetworks for a predicted target from Mycobacterium tuberculosis, its interacting partners and its orthologs. Conclusions The resultant tool provides an attractive view of complex, fully interactivenetworks with components that allow the querying, filtering and manipulation of the visible subset. Moreover, as a web resource, PINV simplifies sharing and publishing, activities which are vital in today’s research collaborative environments. The source code is freely available for download at https://github.com/4ndr01d3/biosual.
General anesthetics are used during medical and surgical procedures to reversibly induce a state of total unconsciousness in patients. Here, we investigate, from a dynamic network perspective, how the cortical and cardiovascular systems behave during anesthesia by applying nonparametric spectral techniques to cortical electroencephalography, electrocardiogram and respiratory signals recorded from anesthetized rats under two drugs, ketamine-xylazine (KX) and pentobarbital (PB). We find that the patterns of low-frequency cortico-cardio-respiratory networkinteractions may undergo significant changes in network activity strengths and in number of network links at different depths of anesthesia dependent upon anesthetics used.
Shiogai, Yuri; Dhamala, Mukesh; Oshima, Kumiko; Hasler, Martin
The interest in indentifying novel biomarkers for early stage breast cancer (BRCA) detection has become grown significantly in recent years. From a view of network biology, one of the emerging themes today is to re-characterize a protein’s biological functions in its molecular network. Although many methods have been presented, including network-based gene ranking for molecular biomarker discovery, and graph clustering for functional module discovery, it is still hard to find systems-level properties hidden in disease specific molecular networks. We reconstructed BRCA-related protein interactionnetwork by using BRCA-associated genes/proteins as seeds, and expanding them in an integrated protein interaction database. We further developed a computational framework based on Ant Colony Optimization to rank network nodes. The task of ranking nodes is represented as the problem of finding optimal density distributions of “ant colonies” on all nodes of the network. Our results revealed some interesting systems-level pattern in BRCA-related protein interactionnetwork.
Social interactions are a very important component in people’s lives. Social network analysis has become a common technique used to model and quantify the properties of social interactions. In this paper, we propose an integrated framework to explore the characteristics of a social network extracted from multimodal dyadic interactions. For our study, we used a set of videos belonging to New York Times’ Blogging Heads opinion blog. The Social Network is represented as an oriented graph, whose directed links are determined by the Influence Model. The links’ weights are a measure of the “influence” a person has over the other. The states of the Influence Model encode automatically extracted audio/visual features from our videos using state-of-the art algorithms. Our results are reported in terms of accuracy of audio/visual data fusion for speaker segmentation and centrality measures used to characterize the extracted social network.
Epidemics seldom occur as isolated phenomena. Typically, two or more viral agents spread within the same host population and may interact dynamically with each other. We present a general model where two viral agents interact via an immunity mechanism as they propagate simultaneously on two networks connecting the same set of nodes. By exploiting a correspondence between the propagation dynamics and a dynamical process performing progressive network generation, we develop an analytical approach that accurately captures the dynamical interaction between epidemics on overlay networks. The formalism allows for overlay networks with arbitrary joint degree distribution and overlap. To illustrate the versatility of our approach, we consider a hypothetical delayed intervention scenario in which an immunizing agent is disseminated in a host population to hinder the propagation of an undesirable agent (e.g., the spread of preventive information in the context of an emerging infectious disease).
Marceau, Vincent; Noël, Pierre-André; Hébert-Dufresne, Laurent; Allard, Antoine; Dubé, Louis J.
Describes a study that investigated the activities of engineering students working on a collaborative design project in a distributed multimedia environment. Topics discussed include learning as a social process; face-to-face and video communication; problem-solving techniques; use of interactive media; the construction of knowledge; and group…
In this paper, we briefly describe an interactive roulette game enabled over a wireless sensor network platform. It basically consists in a train speeding in one way (the spinning roulette) and in a message hopping along some deployed sensors in the other way (the wheeling ball). This demonstration aims at illustrating in an interactive manner the high radio channel randomness
Julien Beaudaux; Antoine Gallais; Romain Kuntz; Julien Montavont; Thomas Noël; Damien Roth; Fabrice Theoleyre; Erkan Valentin
In this paper we present an unsupervised neural network model of bilingual lexical development and interaction. We focus on how the representational structures of the bilingual lexicons can emerge, develop, and interact with each other as a function of the learning history. The results show that: (1) distinct representations for the two lexicons…
We employed the random graph theory approach to analyze the protein-protein interaction database DIP (Feb. 2004), for seven species (S. cerevisiae, H. pylori, E. coli, C. elegans, H. sapiens, M. musculus and D. melanogaster). Several global topological parameters (such as node connectivity, average diameter, node connectivity correlation) were used to characterize these protein-protein interactionnetworks (PINs). The logarithm of the
Correlated motif mining (CMM) is the problem to find overrepresented pairs of patterns, called motif pairs, in interacting protein sequences. Algorithmic solutions for CMM thereby provide a computational method for predicting binding sites for protein interaction. In this paper, we adopt a motif-driven approach where the support of candidate motif pairs is evaluated in the network. We experimentally establish the
Peter Boyen; Frank Neven; Dries Van Dyck; Aalt-jan Van Dijk; Roeland C. H. J. Van Ham
Animal social networks can be extremely complex and are characterized by highly non-random interactions between group members. However, very little is known about the underlying factors affecting interaction preferences, and hence network structure. One possibility is that behavioural differences between individuals, such as how bold or shy they are, can affect the frequency and distribution of their interactions within a network. We tested this using individually marked three-spined sticklebacks (Gasterosteus aculeatus), and found that bold individuals had fewer overall interactions than shy fish, but tended to distribute their interactions more evenly across all group members. Shy fish, on the other hand, tended to associate preferentially with a small number of other group members, leading to a highly skewed distribution of interactions. This was mediated by the reduced tendency of shy fish to move to a new location within the tank when they were interacting with another individual; bold fish showed no such tendency and were equally likely to move irrespective of whether they were interacting or not. The results show that animal social network structure can be affected by the behavioural composition of group members and have important implications for understanding the spread of information and disease in social groups. PMID:18647713
Pike, Thomas W; Samanta, Madhumita; Lindström, Jan; Royle, Nick J
Graphical user interfaces (GUI) provide interactive and intuitive visual communication to power system analysis application programs, enhancing the capabilities of engineers to conduct studies with ease and flexibility. As a result, since the late 1970s, a number of interactive graphical packages for power system analysis have been developed and are in widespread use. Object-oriented programming is gaining popularity, while the
N. Hatziargyriou; J. Jaszczynski; G. Atsaves; D. Agoris
This report considers the effects of new technology (online search services) on user access to information; the role of libraries in providing such access; the structure of a future national information network in the United Kingdom; and general managerial considerations. Seventeen references are cited. (EJS)
The activities under a cooperative agreement for the development of a computer network are briefly summarized. Research activities covered are: computer operating systems optimization and integration; software development and implementation of the IRIS (Infrared Imaging of Shuttle) Experiment; and software design, development, and implementation of the APS (Aerosol Particle System) Experiment.
This study explores some possibilities of social network analysis for studying adolescents' communication patterns. A full network analysis was conducted on third-grade high school students (15 year olds, 137 students) in Belgium. The results pointed out that face-to-face communication was still the most prominent way for information to flow…
This research used survey research to explore and describe the use of computer networks by aerospace engineers. The study population included 2000 randomly selected U.S. aerospace engineers and scientists who subscribed to Aerospace Engineering. A total of 950 usable questionnaires were received by the cutoff date of July 1994. Study results contribute to existing knowledge about both computer network use and the nature of engineering work and communication. We found that 74 percent of mail survey respondents personally used computer networks. Electronic mail, file transfer, and remote login were the most widely used applications. Networks were used less often than face-to-faceinteractions in performing work tasks, but about equally with reading and telephone conversations, and more often than mail or fax. Network use was associated with a range of technical, organizational, and personal factors: lack of compatibility across systems, cost, inadequate access and training, and unwillingness to embrace new technologies and modes of work appear to discourage network use. The greatest positive impacts from networking appear to be increases in the amount of accurate and timely information available, better exchange of ideas across organizational boundaries, and enhanced work flexibility, efficiency, and quality. Involvement with classified or proprietary data and type of organizational structure did not distinguish network users from nonusers. The findings can be used by people involved in the design and implementation of networks in engineering communities to inform the development of more effective networking systems, services, and policies.
Telepresence, especially in the form of interactive video, is becoming critical to modern warfare, delivering intelligence and enhancing situation awareness. This paper describes an interactive video communication system, Indirect Networked Target-Enhanced Robust Video-Interaction Telepresence (INTERVIT), that has been developed at Physical Optics Corporation (POC). The system consists of ground visual sensors, real-time video compression and target assessment and tracking, and secure wireless transmission. The paper describes the design, fabrication and test for an implemented experimental INTERVIT system.
Kostrzewski, Andrew A.; Wang, Wenjian; Kang, Dae S.; Sun, Byung-Kul; Lee, Charles; Kim, Jae-Hyun; Kolesnikov, Kirill; Jannson, Tomasz P.
The modern synthesis of evolutionary theory and genetics has enabled us to discover underlying molecular mechanisms of organismal evolution. We know that in order to maximize an organism's fitness in a particular environment, individual interactions among components of protein and nucleic acid networks need to be optimized by natural selection, or sometimes through random processes, as the organism responds to changes and/or challenges in the environment. Despite the significant role of molecular networks in determining an organism's adaptation to its environment, we still do not know how such inter- and intra-molecular interactions within networks change over time and contribute to an organism's evolvability while maintaining overall network functions. One way to address this challenge is to identify connections between molecular networks and their host organisms, to manipulate these connections, and then attempt to understand how such perturbations influence molecular dynamics of the network and thus influence evolutionary paths and organismal fitness. In the present review, we discuss how integrating evolutionary history with experimental systems that combine tools drawn from molecular evolution, synthetic biology and biochemistry allow us to identify the underlying mechanisms of organismal evolution, particularly from the perspective of protein interactionnetworks.
Complex networks have recently become the focus of research in many fields. Their structure reveals crucial information for the nodes, how they connect and share information. In our work we analyze protein interactionnetworks as complex networks for their functional modular structure and later use that information in the functional annotation of proteins within the network. We propose several graph representations for the protein interactionnetwork, each having different level of complexity and inclusion of the annotation information within the graph. We aim to explore what the benefits and the drawbacks of these proposed graphs are, when they are used in the function prediction process via clustering methods. For making this cluster based prediction, we adopt well established approaches for cluster detection in complex networks using most recent representative algorithms that have been proven as efficient in the task at hand. The experiments are performed using a purified and reliable Saccharomyces cerevisiae protein interactionnetwork, which is then used to generate the different graph representations. Each of the graph representations is later analysed in combination with each of the clustering algorithms, which have been possibly modified and implemented to fit the specific graph. We evaluate results in regards of biological validity and function prediction performance. Our results indicate that the novel ways of presenting the complex graph improve the prediction process, although the computational complexity should be taken into account when deciding on a particular approach.
Topology is an essential aspect of protein structure. The network paradigm is increasingly used to describe the topology and dynamics of proteins. In this paper, the effect of topology on residue interactionnetwork was investigated for two different proteins: Dronpa and a DNA clamp, which have cylindrical and toroidal topologies, respectively. Network metrics including characteristic path lengths, clustering coefficients, and diameters were calculated to investigate their global topology parameters such as small-world properties and packing density. Measures of centrality including betweenness, closeness, and residue centrality were computed to predict residues critical to function. Additionally, the detailed topology of the hydrophobic pocket in Dronpa, and communication pathways across the interface in the DNA clamp, were investigated using the network. The results are presented and discussed with regard to existing residue interactionnetwork properties of globular proteins and elastic network models on Dronpa and the DNA clamp. The topological principle underlying residue interactionnetworks provided insight into the architectural organization of proteins. PMID:24486230
Protein-protein interactionnetworks provide important clues about cell function. However, the picture offered by protein interaction alone is incomplete, because techniques for determining interactions at genome scale lack details as to how they are mediated. Stable protein interactions are thought to be largely mediated by interactions between protein domains while transient interactions occur often between small globular domains and short protein peptides, the so called linear motifs. Recently a number of computational methods to predict interactions between two domains and between a domain and a (possibly modified) peptide have been proposed. In this chapter we review representative computational methods focusing on those that use high throughput protein interactionnetworks to uncover domain-domain and domain-peptide interactions.
In a study of infant smiling, 20 mother-infant dyads were videotaped in normal face-to-faceinteraction when the infants were 9 and 14 weeks of age. Videotapes were used to determine which of two classes of smiling behavior models, either arousal modulation or activation indicator, was most supported by empirical data. Arousal modulation models…
Molecular interactionnetworks, such as those involving protein-protein and protein-DNA interactions, often consist of thousands of nodes or even more, which severely limits the usefulness of many graph drawing tools because they become too slow for interactive analysis of the networks and because they produce cluttered drawings with many edge crossings. We present a new, fast-layout algorithm and its implementation called WebInterViewer for visualizing large-scale molecular interactionnetworks. WebInterViewer (i) finds a layout of the connected components of an entire network, (ii) finds a global layout of nodes with respect to pivot nodes within the connected components and (iii) refines the local layout of each connected component by first relocating midnodes with respect to their cutvertices and the direct neighbors of the cutvertices, and then relocating all nodes with respect to their neighbors within distance 2. The advantages of WebInterViewer over classical graph drawing methods include the facts that (i) it is an order of magnitude faster, (ii) it can visualize data directly from protein interaction databases and (iii) it provides several abstraction and comparison operations for analyzing large-scale biological networks effectively. WebInterViewer is accessible at http://interviewer.inha.ac.kr/. PMID:15215357
Molecular interactionnetworks, such as those involving protein–protein and protein–DNA interactions, often consist of thousands of nodes or even more, which severely limits the usefulness of many graph drawing tools because they become too slow for interactive analysis of the networks and because they produce cluttered drawings with many edge crossings. We present a new, fast-layout algorithm and its implementation called WebInterViewer for visualizing large-scale molecular interactionnetworks. WebInterViewer (i) finds a layout of the connected components of an entire network, (ii) finds a global layout of nodes with respect to pivot nodes within the connected components and (iii) refines the local layout of each connected component by first relocating midnodes with respect to their cutvertices and the direct neighbors of the cutvertices, and then relocating all nodes with respect to their neighbors within distance 2. The advantages of WebInterViewer over classical graph drawing methods include the facts that (i) it is an order of magnitude faster, (ii) it can visualize data directly from protein interaction databases and (iii) it provides several abstraction and comparison operations for analyzing large-scale biological networks effectively. WebInterViewer is accessible at http://interviewer.inha.ac.kr/.
Protein interactions are central to most biological processes. We investigated the dynamics of emergence of the protein interactionnetwork of Saccharomyces cerevisiae by mapping origins of proteins on an evolutionary tree. We demonstrate that evolutionary periods are characterized by distinct connectivity levels of the emerging proteins. We found that the most-connected group of proteins dates to the eukaryotic radiation, and the more ancient group of pre-eukaryotic proteins is less connected. We show that functional classes have different average connectivity levels and that the time of emergence of these functional classes parallels the observed connectivity variation in evolution. We take these findings as evidence that the evolution of function might be the reason for the differences in connectivity throughout evolutionary time. We propose that the understanding of the mechanisms that generate the scale-free protein interactionnetwork, and possibly other biological networks, requires consideration of protein function. PMID:15071090
Kunin, Victor; Pereira-Leal, José B; Ouzounis, Christos A
A major objective of systems biology is to organize molecular interactions as networks and to characterize information-flow within networks. We describe a computational framework to integrate protein-protein interaction (PPI) networks and genetic screens to predict the “signs” of interactions (i.e. activation/inhibition relationships). We constructed a Drosophila melanogaster signed PPI network, consisting of 6,125 signed PPIs connecting 3,352 proteins that can be used to identify positive and negative regulators of signaling pathways and protein complexes. We identified an unexpected role for the metabolic enzymes Enolase and Aldo-keto reductase as positive and negative regulators of proteolysis, respectively. Characterization of the activation/inhibition relationships between physically interacting proteins within signaling pathways will impact our understanding of many biological functions, including signal transduction and mechanisms of disease.
Social media and online communication encourage social interaction but do little to strengthen community relations between people who live in the same area. The aim of this work is to develop a set of requirements, in this initial case from a group of older adults, for an online system aimed at increasing local face-to-face communication and enhancing community interaction. Eleven
David Greathead; Lynne Coventry; Budi Arief; Aad van Moorsel
Interaction research on recasts has been largely confined to examining the effects of recasts delivered in an oral, face-to-face modality. The challenge of creating task conditions in a written interactive mode, in which the dynamism and immediacy of recasts can be brought to bear on L2 development, has been a formidable obstacle to advancing the…
This paper focuses on the contribution of Australian Football League (AFL) players to their team’s on-field network by simulating player interactions within a chosen team list and estimating the net effect on final score margin. A Visual Basic computer program was written, firstly, to isolate the effective interactions between players from a particular team in all 2011 season matches and, secondly, to generate a symmetric interaction matrix for each match. Negative binomial distributions were fitted to each player pairing in the Geelong Football Club for the 2011 season, enabling an interactive match simulation model given the 22 chosen players. Dynamic player ratings were calculated from the simulated network using eigenvector centrality, a method that recognises and rewards interactions with more prominent players in the team network. The centrality ratings were recorded after every network simulation and then applied in final score margin predictions so that each player’s match contribution-and, hence, an optimal team-could be estimated. The paper ultimately demonstrates that the presence of highly rated players, such as Geelong’s Jimmy Bartel, provides the most utility within a simulated team network. It is anticipated that these findings will facilitate optimal AFL team selection and player substitutions, which are key areas of interest to coaches. Network simulations are also attractive for use within betting markets, specifically to provide information on the likelihood of a chosen AFL team list “covering the line ”. Key points A simulated interaction matrix for Australian Rules football players is proposed The simulations were carried out by fitting unique negative binomial distributions to each player pairing in a side Eigenvector centrality was calculated for each player in a simulated matrix, then for the team The team centrality measure adequately predicted the team’s winning margin A player’s net effect on margin could hence be estimated by replacing him in the simulated side with another player
Angiogenesis is the formation of new blood vessels from pre-existing microvessels. Excessive and insufficient angiogenesis have been associated with many diseases including cancer, age-related macular degeneration, ischemic heart, brain, and skeletal muscle diseases. A comprehensive understanding of angiogenesis regulatory processes is needed to improve treatment of these diseases. To identify proteins related to angiogenesis, we developed a novel integrative framework for diverse sources of high-throughput data. The system, called GeneHits, was used to expand on known angiogenesis pathways to construct the angiome, a protein-protein interactionnetwork for angiogenesis. The network consists of 478 proteins and 1,488 interactions. The network was validated through cross validation and analysis of five gene expression datasets from in vitro angiogenesis assays. We calculated the topological properties of the angiome. We analyzed the functional enrichment of angiogenesis-annotated and associated proteins. We also constructed an extended angiome with 1,233 proteins and 5,726 interactions to derive a more complete map of protein-protein interactions in angiogenesis. Finally, the extended angiome was used to identify growth factor signaling networks that drive angiogenesis and antiangiogenic signaling networks. The results of this analysis can be used to identify genes and proteins in different disease conditions and putative targets for therapeutic interventions as high-ranked candidates for experimental validation.
Rivera, Corban G.; Popel, Aleksander S.; Bader, Joel S.
Biological networks consist of a large number of variables that can be coupled by complex multivariate interactions. However, several neuroscience and cell biology experiments have reported that observed statistics of network states can be approximated surprisingly well by maximum entropy models that constrain correlations only within pairs of variables. We would like to verify if this reduction in complexity results from intricacies of biological organization, or if it is a more general attribute of these networks. We generate random networks with p-spin (p>2) interactions, with N spins and M interaction terms. The probability distribution of the network states is then calculated and approximated with a maximum entropy model based on constraining pairwise spin correlations. Depending on the M/N ratio and the strength of the interaction terms, we observe a transition where the pairwise approximation is very good to a region where it fails. This resembles the sat-unsat transition in constraint satisfaction problems. We argue that the pairwise model works when the number of highly probable states is small. We argue that many biological systems must operate in a strongly constrained regime, and hence we expect the pairwise approximation to be accurate for a wide class of problems.
The National Computing Centre (NCC) has developed an interactive video training system for the Scottish Police College to help train police supervisory officers in crowd control at major spectator events, such as football matches. This approach involves technology-enhanced training in a group-learning environment, and may have significant impact…
We present an analysis of protein interactionnetwork data via the comparison of models of network evolution to the observed data. We take a bayesian approach and perform posterior density estimation using an approximate bayesian computation with sequential Monte Carlo method. Our approach allows us to perform model selection over a selection of potential network growth models. The methodology we apply uses a distance defined in terms of graph spectra which captures the network data more naturally than previously used summary statistics such as the degree distribution. Furthermore, we include the effects of sampling into the analysis, to properly correct for the incompleteness of existing datasets, and have analysed the performance of our method under various degrees of sampling. We consider a number of models focusing not only on the biologically relevant class of duplication models, but also including models of scale-free network growth that have previously been claimed to describe such data. We find a preference for a duplication-divergence with linear preferential attachment model in the majority of the interaction datasets considered. We also illustrate how our method can be used to perform multi-model inference of network parameters to estimate properties of the full network from sampled data. PMID:22552917
We present an analysis of protein interactionnetwork data via the comparison of models of network evolution to the observed data. We take a Bayesian approach and perform posterior density estimation using an approximate Bayesian computation with sequential Monte Carlo method. Our approach allows us to perform model selection over a selection of potential network growth models. The methodology we apply uses a distance defined in terms of graph spectra which captures the network data more naturally than previously used summary statistics such as the degree distribution. Furthermore, we include the effects of sampling into the analysis, to properly correct for the incompleteness of existing datasets, and have analysed the performance of our method under various degrees of sampling. We consider a number of models focusing not only on the biologically relevant class of duplication models, but also including models of scale-free network growth that have previously been claimed to describe such data. We find a preference for a duplication-divergence with linear preferential attachment model in the majority of the interaction datasets considered. We also illustrate how our method can be used to perform multi-model inference of network parameters to estimate properties of the full network from sampled data.
Myocardial infarction (MI) is a serious heart disease. The cardiac cells of patients with MI will die due to lack of blood for a long time. In this study, we aimed to find new targets for MI diagnosis and therapy. We downloaded GSE22229 including 12 blood samples from healthy persons and GSE29111 from Gene Expression Omnibus including 36 blood samples from MI patients. Then we identified differentially expressed genes (DEGs) in patients with MI compared to normal controls with p value < 0.05 and |logFC| > 1. Furthermore, interactionnetwork and sub-network of these of these DEGs were constructed by NetBox. Linker genes were screened in the Global Network database. The degree of linker genes were calculated by igraph package in R language. Gene ontology and kyoto encyclopedia of genes and genomes pathway analysis were performed for DEGs and network modules. A total of 246 DEGs were identified in MI, which were enriched in the immune response. In the interactionnetwork, LCK, CD247, CD3D, FYN, HLA-DRA, IL2, CD8A CD3E, CD4, CD3G had high degree, among which CD3E, CD4, CD3G were DEGs while others were linker genes screened from Global Network database. Genes in the sub-network were also enriched in the immune response pathway. The genes with high degree may be biomarkers for MI diagnosis and therapy. PMID:24748432
Background Network representations of cell-biological signaling processes frequently contain large numbers of interacting molecular and multi-molecular components that can exist in, and switch between, multiple biochemical and/or structural states. In addition, the interaction categories (associations, dissociations and transformations) in such networks cannot satisfactorily be mapped onto simple arrows connecting pairs of components since their specifications involve information such as reaction rates and conditions with regard to the states of the interacting components. This leads to the challenge of having to reconcile competing objectives: providing a high-level overview without omitting relevant information, and showing interaction specifics while not overwhelming users with too much detail displayed simultaneously. This problem is typically addressed by splitting the information required to understand a reaction network model into several categories that are rendered separately through combinations of visualizations and/or textual and tabular elements, requiring modelers to consult several sources to obtain comprehensive insights into the underlying assumptions of the model. Results We report the development of an application, the Simmune NetworkViewer, that visualizes biochemical reaction networks using iconographic representations of protein interactions and the conditions under which the interactions take place using the same symbols that were used to specify the underlying model with the Simmune Modeler. This approach not only provides a coherent model representation but, moreover, following the principle of “overview first, zoom and filter, then details-on-demand,” can generate an overview visualization of the global network and, upon user request, presents more detailed views of local sub-networks and the underlying reaction rules for selected interactions. This visual integration of information would be difficult to achieve with static network representations or approaches that use scripted model specifications without offering simple but detailed symbolic representations of molecular interactions, their conditions and consequences in terms of biochemical modifications. Conclusions The Simmune NetworkViewer provides concise, yet comprehensive visualizations of reaction networks created in the Simmune framework. In the near future, by adopting the upcoming SBML standard for encoding multi-component, multi-state molecular complexes and their interactions as input, the NetworkViewer will, moreover, be able to offer such visualization for any rule-based model that can be exported to that standard.
This article introduces fundamental concepts to guide the analysis and interpretation of drug-target interactionnetworks. An overview of the generation and integration of interactionnetworks is followed by key strategies for extracting biologically meaningful information. The article highlights how this information can enable novel translational and clinically motivated applications. Important advances for the discovery of new treatments and for the detection of adverse drug effects are discussed. Examples of applications and findings originating from cardiovascular research are presented. The review ends with a discussion of crucial challenges and opportunities. PMID:22977007
Embedded within large-scale protein interactionnetworks are signaling pathways that encode response cascades in the cell. Unfortunately, even for well-studied species like S. cerevisiae, only a fraction of all true protein interactions are known, which makes it difficult to reason about the exact flow of signals and the corresponding causal relations in the network. To help address this problem, we introduce a framework for predicting new interactions that aid connectivity between upstream proteins (sources) and downstream transcription factors (targets) of a particular pathway. Our algorithms attempt to globally minimize the distance between sources and targets by finding a small set of shortcut edges to add to the network. Unlike existing algorithms for predicting general protein interactions, by focusing on proteins involved in specific responses our approach homes-in on pathway-consistent interactions. We applied our method to extend pathways in osmotic stress response in yeast and identified several missing interactions, some of which are supported by published reports. We also performed experiments that support a novel interaction not previously reported. Our framework is general and may be applicable to edge prediction problems in other domains.
One widely known drawback of enzymes is their instability in diverse conditions. The thermostability of enzymes is particularly relevant for industrial applications because operation at high temperatures has the advantage of a faster reaction rate. Protein stability is mainly determined in this study by intra-molecular hydrophobic interactions that have a collective and 3-dimensional clustering effect. To interpret the thermostability of enzymes, network analysis was introduced into the protein structure, and a network parameter of structural hierarchy, k of k-clique, was used to discern more developed hydrophobic interaction clusters in the protein structure. The favorable clustering conformations of hydrophobic residues, which seemed to be important for protein thermostability, were discovered by the application of a network analysis to hydrophobic interactions of GH11 xylanases. Coordinating higher k-clique hydrophobic interaction clusters through the site-directed mutagenesis of the model enzyme, Bacillus circulans xylanase, stabilized the local structure and thus improved thermostability, such that the enzyme half-life and melting temperature increased by 78 fold and 8.8 °C, respectively. This study highlights the advantages of interpreting collective hydrophobic interaction patterns and their structural hierarchy and the possibility of applying network analysis to the thermostabilization of enzymes. PMID:22642881
Antigen receptors play a central role in adaptive immune responses. Although the molecular networks associated with these receptors have been extensively studied, we currently lack a systems-level understanding of how combinations of non-covalent interactions and post-translational modifications are regulated during signaling to impact cellular decision-making. To fill this knowledge gap, it will be necessary to formalize and piece together information about individual molecular mechanisms to form large-scale computational models of signaling networks. To this end, we have developed an interaction library for signaling by the high-affinity IgE receptor, Fc?RI. The library consists of executable rules for protein–protein and protein–lipid interactions. This library extends earlier models for Fc?RI signaling and introduces new interactions that have not previously been considered in a model. Thus, this interaction library is a toolkit with which existing models can be expanded and from which new models can be built. As an example, we present models of branching pathways from the adaptor protein Lat, which influence production of the phospholipid PIP3 at the plasma membrane and the soluble second messenger IP3. We find that inclusion of a positive feedback loop gives rise to a bistable switch, which may ensure robust responses to stimulation above a threshold level. In addition, the library is visualized to facilitate understanding of network circuitry and identification of network motifs.
Chylek, Lily A.; Holowka, David A.; Baird, Barbara A.; Hlavacek, William S.
The spread of certain diseases can be promoted, in some cases substantially, by prior infection with another disease. One example is that of HIV, whose immunosuppressant effects significantly increase the chances of infection with other pathogens. Such coinfection processes, when combined with nontrivial structure in the contact networks over which diseases spread, can lead to complex patterns of epidemiological behavior. Here we consider a mathematical model of two diseases spreading through a single population, where infection with one disease is dependent on prior infection with the other. We solve exactly for the sizes of the outbreaks of both diseases in the limit of large population size, along with the complete phase diagram of the system. Among other things, we use our model to demonstrate how diseases can be controlled not only by reducing the rate of their spread, but also by reducing the spread of other infections upon which they depend.
Identifying protein complexes in protein-protein interaction (PPI) networks is a fundamental problem in computational biology. High-throughput experimental techniques have generated large, experimentally detected PPI datasets. These interactions represent a rich source of data that can be used to detect protein complexes; however, such interactions contain much noise. Therefore, these interactions should be validated before they could be applied to detect protein complexes. We propose an efficient measure to estimate PPI reliability (PPIR) and reduce noise level in two different yeast PPI networks. PPIRU, which is a new protein complex clustering algorithm based on PPIR, is introduced. Experiments demonstrated that interactome graph weighting methods incorporating PPIR clearly improve the results of several clustering algorithms. PPIR also outperforms other PPI graph weighting schemes in most cases. We compare PPIRU with several efficient, existing clustering algorithms and reveal that the accuracy values of PPIRU clusters are much higher than those of other algorithms. PMID:24654850
\\u000a The game industry continues to evolves its techniques for extracting the most realistic ‘immersion’ experience for players\\u000a given the vagaries on best-effort Internet service. A key challenge for service providers is understanding the characteristics\\u000a of traffic imposed on networks by games, and their service quality requirements. Interactive online games are particularly\\u000a susceptible to the side effects of other non-interactive (or
Background Understanding and ameliorating the effects of network damage are of significant interest, due in part to the variety of applications in which network damage is relevant. For example, the effects of genetic mutations can cascade through within-cell signaling and regulatory networks and alter the behavior of cells, possibly leading to a wide variety of diseases. The typical approach to mitigating network perturbations is to consider the compensatory activation or deactivation of system components. Here, we propose a complementary approach wherein interactions are instead modified to alter key regulatory functions and prevent the network damage from triggering a deregulatory cascade. Results We implement this approach in a Boolean dynamic framework, which has been shown to effectively model the behavior of biological regulatory and signaling networks. We show that the method can stabilize any single state (e.g., fixed point attractors or time-averaged representations of multi-state attractors) to be an attractor of the repaired network. We show that the approach is minimalistic in that few modifications are required to provide stability to a chosen attractor and specific in that interventions do not have undesired effects on the attractor. We apply the approach to random Boolean networks, and further show that the method can in some cases successfully repair synchronous limit cycles. We also apply the methodology to case studies from drought-induced signaling in plants and T-LGL leukemia and find that it is successful in both stabilizing desired behavior and in eliminating undesired outcomes. Code is made freely available through the software package BooleanNet. Conclusions The methodology introduced in this report offers a complementary way to manipulating node expression levels. A comprehensive approach to evaluating network manipulation should take an "all of the above" perspective; we anticipate that theoretical studies of interaction modification, coupled with empirical advances, will ultimately provide researchers with greater flexibility in influencing system behavior.
Competing endogenous RNAs (ceRNAs) were recently introduced as RNA transcripts that affect each other's expression level through competition for their microRNA (miRNA) coregulators. This stems from the bidirectional effects between miRNAs and their target RNAs, where a change in the expression level of one target affects the level of the miRNA regulator, which in turn affects the level of other targets. By the same logic, miRNAs that share targets compete over binding to their common targets and therefore also exhibit ceRNA-like behavior. Taken together, perturbation effects could propagate in the posttranscriptional regulatory network through a path of coregulated targets and miRNAs that share targets, suggesting the existence of distant ceRNAs. Here we study the prevalence of distant ceRNAs and their effect in cellular networks. Analyzing the network of miRNA-target interactions deciphered experimentally in HEK293 cells, we show that it is a dense, intertwined network, suggesting that many nodes can act as distant ceRNAs of one another. Indeed, using gene expression data from a perturbation experiment, we demonstrate small, yet statistically significant, changes in gene expression caused by distant ceRNAs in that network. We further characterize the magnitude of the propagated perturbation effect and the parameters affecting it by mathematical modeling and simulations. Our results show that the magnitude of the effect depends on the generation and degradation rates of involved miRNAs and targets, their interaction rates, the distance between the ceRNAs and the topology of the network. Although demonstrated for a miRNA-mRNA regulatory network, our results offer what to our knowledge is a new view on various posttranscriptional cellular networks, expanding the concept of ceRNAs and implying possible distant cross talk within the network, with consequences for the interpretation of indirect effects of gene perturbation. PMID:24853754
An “infection,” understood here in a very broad sense, can be propagated through the network of social contacts among individuals. These social contacts include both “close” contacts and “casual” encounters among individuals in transport, leisure, shopping, etc. Knowing the first through the study of the social networks is not a difficult task, but having a clear picture of the network of casual contacts is a very hard problem in a society of increasing mobility. Here we assume, on the basis of several pieces of empirical evidence, that the casual contacts between two individuals are a function of their social distance in the network of close contacts. Then, we assume that we know the network of close contacts and infer the casual encounters by means of nonrandom long-range (LR) interactions determined by the social proximity of the two individuals. This approach is then implemented in a susceptible-infected-susceptible (SIS) model accounting for the spread of infections in complex networks. A parameter called “conductance” controls the feasibility of those casual encounters. In a zero conductance network only contagion through close contacts is allowed. As the conductance increases the probability of having casual encounters also increases. We show here that as the conductance parameter increases, the rate of propagation increases dramatically and the infection is less likely to die out. This increment is particularly marked in networks with scale-free degree distributions, where infections easily become epidemics. Our model provides a general framework for studying epidemic spreading in networks with arbitrary topology with and without casual contacts accounted for by means of LR interactions.
Estrada, Ernesto; Kalala-Mutombo, Franck; Valverde-Colmeiro, Alba
This research study reports the findings of how support networks impact the success of African American women in completing their college degree. A phenomenological research methodology of 10 African American women participants of in-depth face-to-face interviews was used to collect the data. Fifty percent of the women completed their degree and…
Complex cellular processes are modular and are accomplished by the concerted action of functional modules (Ravasz et al., Science 2002;297:1551-1555; Hartwell et al., Nature 1999;402:C47-52). These modules encompass groups of genes or proteins involved in common elementary biological functions. One important and largely unsolved goal of functional genomics is the identification of functional modules from genomewide information, such as transcription profiles or protein interactions. To cope with the ever-increasing volume and complexity of protein interaction data (Bader et al., Nucleic Acids Res 2001;29:242-245; Xenarios et al., Nucleic Acids Res 2002;30:303-305), new automated approaches for pattern discovery in these densely connected interactionnetworks are required (Ravasz et al., Science 2002;297:1551-1555; Bader and Hogue, Nat Biotechnol 2002;20:991-997; Snel et al., Proc Natl Acad Sci USA 2002;99:5890-5895). In this study, we successfully isolate 1046 functional modules from the known protein interactionnetwork of Saccharomyces cerevisiae involving 8046 individual pair-wise interactions by using an entirely automated and unsupervised graph clustering algorithm. This systems biology approach is able to detect many well-known protein complexes or biological processes, without reference to any additional information. We use an extensive statistical validation procedure to establish the biological significance of the detected modules and explore this complex, hierarchical network of modular interactions from which pathways can be inferred. PMID:14705023
Pereira-Leal, Jose B; Enright, Anton J; Ouzounis, Christos A
We study a class of composed networks that are formed by two tree networks, TP and TA, whose end points touch each other through a bipartite network B. We explore this network using a functional approach. We are interested in how much the topology, or the structure, of TX ( X=A or P) determines the links of B. This composed structure is a useful model in evolutionary biology, where TP and TA are the phylogenetic trees of plants and animals that interact in an ecological community. We make use of ecological networks of dispersion of fruits, which are formed by frugivorous animals and plants with fruits; the animals, usually birds, eat fruits and disperse their seeds. We analyse how the phylogeny of TX determines or is correlated with B using a Monte Carlo approach. We use the phylogenetic distance among elements that interact with a given species to construct an index ? that quantifies the influence of TX over B. The algorithm is based on the assumption that interaction matrices that follows a phylogeny of TX have a total phylogenetic distance smaller than the average distance of an ensemble of Monte Carlo realisations. We find that the effect of phylogeny of animal species is more pronounced in the ecological matrix than plant phylogeny.
Cruz, Claudia P. T.; Fonseca, Carlos Roberto; Corso, Gilberto
Numerous approaches have been taken to study protein interactions, such as tagged protein complex isolation followed by mass spectrometry, yeast two-hybrid methods, fluorescence resonance energy transfer, surface plasmon resonance, site-directed mutagenesis, and crystallography. Membrane protein interactions pose significant challenges due to the need to solubilize membranes without disrupting protein-protein interactions. Traditionally, analysis of isolated protein complexes by high-resolution 2D gel electrophoresis has been the main method used to obtain an overall picture of proteome constituents and interactions. However, this method is time consuming, labor intensive, detects only abundant proteins and is not suitable for the coverage required to elucidate large interactionnetworks. In this review, we discuss the application of various methods to elucidate interactions involving membrane proteins. These techniques include methods for the direct isolation of single complexes or interactors as well as methods for characterization of entire subcellular and cellular interactomes.
Hooker, Brian S.; Bigelow, Diana J.; Lin, Chiann Tso
Unilateral spatial neglect is a disabling condition, frequently observed after right-hemisphere damage (RHD), and associated with poor functional recovery. Clinical and experimental evidence indicates that attentional impairments are prominent in neglect. Recent brain imaging and behavioral studies in neglect patients and healthy individuals have provided insights into the mechanisms of attention and have revealed interactions between putative attentional networks. We recruited 16 RHD patients and 16 neurologically intact observers to perform a lateralized version of the Attention Network Test devised by Posner and co-workers (Fan et al., 2002). The results showed evidence of interaction between attentional networks during conflict resolution. Phasic alertness improved the orienting deficit to left-sided targets, reducing the interference of distracters in the neglected visual field, thus facilitating conflict resolution in the majority of patients. Modulating alertness may be an important way of improving basic deficits associated with neglect, such as those affecting spatial orienting. PMID:21377668
Chica, Ana B; Thiebaut de Schotten, Michel; Toba, Monica; Malhotra, Paresh; Lupiáñez, Juan; Bartolomeo, Paolo
This article presents the sociometric analysis of the interactions in a forum of a social network created for the professional development of Portuguese-speaking teachers. The main goal of the forum, which was titled Stricto Sensu, was to discuss the educational value of programmes that joined the distance learning model in Brazil. The empirical…
We wish to exploit the complementary characteristics of marine sensor networks and autonomous vehicles through interaction and cooperation to achieve tasks that neither can accomplish alone - large-scale, long duration perception of the environment and response to changes in that environment. We outline and experimentally evaluate a new programming and communications framework that supports the integration of autonomous surface and
It has been well recognized that the pace of the development of new drugs and therapeutic interventions lags far behind biological knowledge discovery. Network-based approaches have emerged as a promising alternative to accelerate the discovery of new safe and effective drugs. Based on the integration of several biological resources including two recently published datasets i.e., Drug-target interactions in myocardial infarction (My-DTome) and drug-domain interactionnetwork, this paper reports the association between drugs and protein domains in the context of myocardial infarction (MI). A MI drug-domain interactionnetwork, My-DDome, was firstly constructed, followed by topological analysis and functional characterization of the network. The results show that My-DDome has a very clear modular structure, where drugs interacting with the same domain(s) within each module tend to have similar therapeutic effects. Moreover it has been found that drugs acting on blood and blood forming organs (ATC code B) and sensory organs (ATC code S) are significantly enriched in My-DDome (p < 0.000001), indicating that by incorporating protein domain information into My-DTome, more detailed insights into the interplay between drugs, their known targets, and seemingly unrelated proteins can be revealed. PMID:23974657
Predicting protein function is one of the most challenging problems of the post-genomic era. The development of experimental methods for genome scale analysis of molecular interactionnetworks has provided new approaches to inferring protein function. There are various approaches available for deducing the function of proteins of unknown function using protein information. In this paper, the reliable methods for assigning
An interacting multi- agent system in a network can behave like a nature - inspired Smart System (SS) exhibiting the four salient properties of an Artificial Life System (ALS): (i) Collective, coordinated and efficient (ii) Self -organization and emergence (iii) Power law scaling or scale invariance under emergence (iv) Adaptive, fault tolerant and resilient against damage. We explain how these
Background Characterizing the structural properties of protein interactionnetworks will help illuminate the organizational and functional relationships among elements in biological systems. Results In this paper, we present a systematic exploration of the core/periphery structures in protein interactionnetworks (PINs). First, the concepts of cores and peripheries in PINs are defined. Then, computational methods are proposed to identify two types of cores, k-plex cores and star cores, from PINs. Application of these methods to a yeast protein interactionnetwork has identified 110 k-plex cores and 109 star cores. We find that the k-plex cores consist of either "party" proteins, "date" proteins, or both. We also reveal that there are two classes of 1-peripheral proteins: "party" peripheries, which are more likely to be part of protein complex, and "connector" peripheries, which are more likely connected to different proteins or protein complexes. Our results also show that, besides connectivity, other variations in structural properties are related to the variation in biological properties. Furthermore, the negative correlation between evolutionary rate and connectivity are shown toysis. Moreover, the core/periphery structures help to reveal the existence of multiple levels of protein expression dynamics. Conclusion Our results show that both the structure and connectivity can be used to characterize topological properties in protein interactionnetworks, illuminating the functional organization of cellular systems.
Luo, Feng; Li, Bo; Wan, Xiu-Feng; Scheuermann, Richard H
Identifying lethal proteins is important for understanding the intricate mechanism gov- erning life. Researchers have shown that the lethality of a protein can be computed based on its topological position in the protein-protein interaction (PPI) network. Performance of current approaches has been less than satisfactory as the lethality of a protein is a functional characteristic that cannot be determined solely
This paper presents a tool for uncovering bugs due to inter- active complexity in networked sensing applications. Such bugs are not localized to one component that is faulty, but rather result from complex and unexpected interactions be- tween multiple often individually non-faulty components. Moreover, the manifestations of these bugs are often not repeatable, making them particularly hard to find, as
Mohammad Maifi Hasan Khan; Hieu Khac Le; Hossein Ahmadi; Tarek F. Abdelzaher; Jiawei Han
Background Protein-protein interaction (PPI) networks carry vital information about proteins' functions. Analysis of PPI networks associated with specific disease systems including cancer helps us in the understanding of the complex biology of diseases. Specifically, identification of similar and frequently occurring patterns (network motifs) across PPI networks will provide useful clues to better understand the biology of the diseases. Results In this study, we developed a novel pattern-mining algorithm that detects cancer associated functional subgraphs occurring in multiple cancer PPI networks. We constructed nine cancer PPI networks using differentially expressed genes from the Oncomine dataset. From these networks we discovered frequent patterns that occur in all networks and at different size levels. Patterns are abstracted subgraphs with their nodes replaced by node cluster IDs. By using effective canonical labeling and adopting weighted adjacency matrices, we are able to perform graph isomorphism test in polynomial running time. We use a bottom-up pattern growth approach to search for patterns, which allows us to effectively reduce the search space as pattern sizes grow. Validation of the frequent common patterns using GO semantic similarity showed that the discovered subgraphs scored consistently higher than the randomly generated subgraphs at each size level. We further investigated the cancer relevance of a select set of subgraphs using literature-based evidences. Conclusion Frequent common patterns exist in cancer PPI networks, which can be found through effective pattern mining algorithms. We believe that this work would allow us to identify functionally relevant and coherent subgraphs in cancer networks, which can be advanced to experimental validation to further our understanding of the complex biology of cancer.
A typical instrument to pursue analysis in complex network studies is the analysis of the statistical distributions. They are usually computed for measures which characterize network topology, and are aimed at capturing both structural and dynamics aspects. Protein-protein interactionnetworks (PPIN) have also been studied through several measures. It is in general observed that a power law is expected to characterize scale-free networks. However, mixing the original noise cover with outlying information and other system-dependent fluctuations makes the empirical detection of the power law a difficult task. As a result the uncertainty level increases when looking at the observed sample; in particular, one may wonder whether the computed features may be sufficient to explain the interactome. We then address noise problems by implementing both decomposition and denoising techniques that reduce the impact of factors known to affect the accuracy of power law detection.
The study of human interactions is of central importance for understanding the behavior of individuals, groups, and societies. Here, we observe the formation and evolution of networks by monitoring the addition of all new links, and we analyze quantitatively the tendencies used to create ties in these evolving online affiliation networks. We show that an accurate estimation of these probabilistic tendencies can be achieved only by following the time evolution of the network. Inferences about the reason for the existence of links using statistical analysis of network snapshots must therefore be made with great caution. Here, we start by characterizing every single link when the tie was established in the network. This information allows us to describe the probabilistic tendencies of tie formation and extract meaningful sociological conclusions. We also find significant differences in behavioral traits in the social tendencies among individuals according to their degree of activity, gender, age, popularity, and other attributes. For instance, in the particular data sets analyzed here, we find that women reciprocate connections 3 times as much as men and that this difference increases with age. Men tend to connect with the most popular people more often than women do, across all ages. On the other hand, triangular tie tendencies are similar, independent of gender, and show an increase with age. These results require further validation in other social settings. Our findings can be useful to build models of realistic social network structures and to discover the underlying laws that govern establishment of ties in evolving social networks.
Two-month-old infants (N = 29) participated in face-to-faceinteractions with their mothers and with strangers. The contingent responsiveness for smiles and vocalizations, while attending to the partner, was assessed for each partner in both interactions. For smiles and for vocalizations, infants were less responsive to the stranger relative to…
Associations of 6-week postpartum maternal self-criticism and dependency with 4-month mother-infant self- and interactive contingencies during face-to-face play were investigated in 126 dyads. Infant and mother face, gaze, touch, and vocal quality were coded second by second from split-screen videotape. Self- and interactive contingencies were…
Small modifications of the molecular structure of a ligand sometimes cause strong gains in binding affinity to a protein target, rendering a weakly active chemical series suddenly attractive for further optimization. Our goal in this study is to better rationalize and predict the occurrence of such interaction hot-spots in receptor binding sites. To this end, we introduce two new concepts into the computational description of molecular recognition. First, we take a broader view of noncovalent interactions and describe protein–ligand binding with a comprehensive set of favorable and unfavorable contact types, including f