Social attraction in video-mediated communication:The role of nonverbal affiliative behavior

The first aim of this study was to analyze video-mediated communication (VMC), in comparison to face-to-face (FTF) communication, and the effect it has on how communicators express nonverbal affiliative behaviors relevant for social attraction. Second, this study aimed to discover whether these nonverbal expressions relate to communicators’ social attraction. An experiment with 93 cross-sex dyads was conducted, with a get-acquainted exercise in a VMC or a FTF condition. Our findings revealed that communicators in VMC smiled more and spoke louder. In addition, VMC interactants displayed less facial touching than FTF interactants. Finally, more gaze aversion and a higher speech rate were found to influence social attraction. These findings have implications for research on cue-rich computer-mediated communication (CMC) and the way in which communicators nonverbally express themselves in comparison to copresent FTF communication. Additionally, this study has implications for social information processing theory which may be extended to include cue-rich forms of CMC

REAL DECISIONS IN VIRTUAL WORLDS: TEAM COLLABORATION AND DECISION MAKING IN 3D VIRTUAL WORLDS

This study investigates how 3D virtual worlds (3DVWs) support team collaboration. Based on Media Synchronicity Theory, we pose that the shared environment and avatar-based interaction allowed by 3DVWs aid convergence processes in teams working on a decision making task, leading to increased shared understanding between team members. This increases performance of decision making teams. An experiment was conducted in which 70 teams of 3 participants had to decide on a spatial planning issue. The teams interacted using synchronous text-based chat, a 3D virtual decision room, or were present in the virtual environment mirroring the spatial planning task. Results revealed that in both the virtual decision room and the virtual environment shared understanding was higher than in the text-based chat condition. This led to higher task performance in terms of consensus, satisfaction, and cohesion. Our results show that 3DVWs offer potential for team collaboration over more traditional text-based collaboration technologies

Does attachment style moderate the effect of computer-mediated versus face-to-face conflict discussions?

Successful conflict resolution is important in romantic relationships. With the advent of computer-mediated communication (CMC), partners can resolve conflict using CMC. But is CMC as effective as face-to-face communication for conflict resolution? And does the effectiveness depend on attachment style? We asked 100 romantic couples to discuss a conflict topic and randomly assigned them to do so face-to-face or via CMC. Levels of distress, anger, and conflict resolution did not differ between face-to-face and CMC discussions.Attachment style did not moderate these findings. A more anxious and a more avoidant attachment style were associated with higher levels of distress andanger. We conclude that there is no indication that resolving conflict face-to-face has advantages over resolving conflict via CMC

Modeling movement disorders - CRPS-related dystonia explained by abnormal proprioceptive reflexes

AbstractHumans control their movements using adaptive proprioceptive feedback from muscle afferents. The interaction between proprioceptive reflexes and biomechanical properties of the limb is essential in understanding the etiology of movement disorders. A non-linear neuromuscular model of the wrist incorporating muscle dynamics and neural control was developed to test hypotheses on fixed dystonia. Dystonia entails sustained muscle contractions resulting in abnormal postures. Lack of inhibition is often hypothesized to result in hyperreflexia (exaggerated reflexes), which may cause fixed dystonia. In this study the model-simulated behavior in case of several abnormal reflex settings was compared to the clinical features of dystonia: abnormal posture, sustained muscle contraction, increased stiffness, diminished voluntary control and activity-aggravation.The simulation results were rated to criteria based on characteristic features of dystonia. Three abnormal reflex scenarios were tested: (1) increased reflex sensitivity—increased sensitivity of both the agonistic and antagonistic reflex pathways; (2) imbalanced reflex offset—a static offset to the reflex pathways on the agonistic side only; and (3) imbalanced reflex sensitivity—increased sensitivity of only the agonistic reflex pathways.Increased reflex sensitivity did not fully account for the features of dystonia, despite distinct motor dysfunction, since no abnormal postures occurred. Although imbalanced reflex offset did result in an abnormal posture, it could not satisfy other criteria. Nevertheless, imbalanced reflex sensitivity with unstable force feedback in one of the antagonists closely resembled all features of dystonia. The developed neuromuscular model is an effective tool to test hypotheses on the underlying pathophysiology of movement disorders

Bioactive secondary metabolites with multiple activities from a fungal endophyte

In order to replace particularly biohazardous nematocides, there is a strong drive to finding natural product-based alternatives with the aim of containing nematode pests in agriculture. The metabolites produced by the fungal endophyte Fusarium oxysporum 162 when cultivated on rice media were isolated and their structures elucidated. Eleven compounds were obtained, of which six were isolated from a Fusarium spp. for the first time. The three most potent nematode-antagonistic compounds, 4-hydroxybenzoic acid, indole-3-acetic acid (IAA) and gibepyrone D had LC50 values of 104, 117 and 134 μg ml−1, respectively, after 72 h. IAA is a well-known phytohormone that plays a role in triggering plant resistance, thus suggesting a dual activity, either directly, by killing or compromising nematodes, or indirectly, by inducing defence mechanisms against pathogens (nematodes) in plants. Such compounds may serve as important leads in the development of novel, environmental friendly, nematocides

Different Bumps in the Road: The Emotional Dynamics of Couple Disagreements in Belgium and Japan

In the present study, we propose that the emotional “bumps” that couples experience during relationship disagreements differ systematically among cultures. We predicted that self-assertive emotions such as anger or strength play a central role in Belgium, where they are instrumental for relational independence. In comparison, other-focused emotions such as shame or empathy for the partner should play a central role in Japan, where they support relational interdependence. Romantic couples from Belgium (n = 58) and Japan (n = 80) discussed relationship disagreements in the lab, which were video-recorded. After the interaction, participants separately rated their emotional experience during video-mediated recall. We identified the emotions that played a central role during the interactions in terms of attractors; these are the emotions around which couples stabilize and that likely play a central role in realizing different relationship ideals. In line with our predictions, attractors reflected states of the interpersonal emotional system that support independence in Belgium (e.g., angry or strong feelings) and interdependence (e.g., empathy) in Japan. Moreover, we found that—at least in Belgium—having more culturally typical interactions was associated with a stronger endorsement of culturally valued relationship ideals and, in turn, better relational functioning

Spinodal Decomposition in Binary Gases

We carried out three-dimensional simulations, with about 1.4 million particles, of phase segregation in a low density binary fluid mixture, described mesoscopically by energy and momentum conserving Boltzmann-Vlasov equations. Using a combination of Direct Simulation Monte Carlo(DSMC) for the short range collisions and a version of Particle-In-Cell(PIC) evolution for the smooth long range interaction, we found dynamical scaling after the ratio of the interface thickness(whose shape is described approximately by a hyperbolic tangent profile) to the domain size is less than ~0.1. The scaling length R(t) grows at late times like t^alpha, with alpha=1 for critical quenches and alpha=1/3 for off-critical ones. We also measured the variation of temperature, total particle density and hydrodynamic velocity during the segregation process.Comment: 11 pages, Revtex, 4 Postscript figures, submitted to PR

The geometry of the Barbour-Bertotti theories I. The reduction process

The dynamics of $N\geq 3$ interacting particles is investigated in the non-relativistic context of the Barbour-Bertotti theories. The reduction process on this constrained system yields a Lagrangian in the form of a Riemannian line element. The involved metric, degenerate in the flat configuration space, is the first fundamental form of the space of orbits of translations and rotations (the Leibniz group). The Riemann tensor and the scalar curvature are computed by a generalized Gauss formula in terms of the vorticity tensors of generators of the rotations. The curvature scalar is further given in terms of the principal moments of inertia of the system. Line configurations are singular for $N\neq 3$. A comparison with similar methods in molecular dynamics is traced.Comment: 15 pages, to appear in Classical and Quantum Gravit

Meiosis Drives Extraordinary Genome Plasticity in the Haploid Fungal Plant Pathogen Mycosphaerella graminicola

Meiosis in the haploid plant-pathogenic fungus Mycosphaerella graminicola results in eight ascospores due to a mitotic division following the two meiotic divisions. The transient diploid phase allows for recombination among homologous chromosomes. However, some chromosomes of M. graminicola lack homologs and do not pair during meiosis. Because these chromosomes are not present universally in the genome of the organism they can be considered to be dispensable. To analyze the meiotic transmission of unequal chromosome numbers, two segregating populations were generated by crossing genetically unrelated parent isolates originating from Algeria and The Netherlands that had pathogenicity towards durum or bread wheat, respectively. Detailed genetic analyses of these progenies using high-density mapping (1793 DArT, 258 AFLP and 25 SSR markers) and graphical genotyping revealed that M. graminicola has up to eight dispensable chromosomes, the highest number reported in filamentous fungi. These chromosomes vary from 0.39 to 0.77 Mb in size, and represent up to 38% of the chromosomal complement. Chromosome numbers among progeny isolates varied widely, with some progeny missing up to three chromosomes, while other strains were disomic for one or more chromosomes. Between 15–20% of the progeny isolates lacked one or more chromosomes that were present in both parents. The two high-density maps showed no recombination of dispensable chromosomes and hence, their meiotic processing may require distributive disjunction, a phenomenon that is rarely observed in fungi. The maps also enabled the identification of individual twin isolates from a single ascus that shared the same missing or doubled chromosomes indicating that the chromosomal polymorphisms were mitotically stable and originated from nondisjunction during the second division and, less frequently, during the first division of fungal meiosis. High genome plasticity could be among the strategies enabling this versatile pathogen to quickly overcome adverse biotic and abiotic conditions in wheat field

Stealth Branes

We discuss the brane world model of Dvali, Gabadadze and Porrati in which branes evolve in an infinite bulk and the brane curvature term is added to the action. If Z_2 symmetry between the two sides of the brane is not imposed, we show that the model admits the existence of "stealth branes" which follow the standard 4D internal evolution and have no gravitational effect on the bulk space. Stealth branes can nucleate spontaneosly in a Minkowski bulk. This process is described by the standard 4D quantum cosmology formalism with tunneling boundary conditions for the brane world wave function. The notorious ambiguity in the choice of boundary conditions is fixed in this case due to the presence of the embedding spacetime. We also point to some problematic aspects of models admitting stealth brane solutions.Comment: 24 pages; Final version, to appear in Phys. Rev. D. The discussion of "embeddability obstruction" is removed (thanks to Takahiro Tanaka who convinced us that there is no such obstruction