Interactions during growth eclipse interactions during flowering for determining plant fecundity in pollinator-sharing annual plants

Species interactions are foundational to ecological theory, but studies often reduce the complex nature of species interactions. In plant ecology, the result is that interactions during vegetative growth and flowering are considered separately, though both can affect fecundity. Here we use a system of annual flowering plants in the genus Clarkia to ask how interactions during flowering and growth contribute to plant interactions, and if pollinator behaviors explain apparent patterns in plant interactions during flowering. We measure seed success and fecundity of Clarkia focal plants in experimental interaction plots with the effect of pollinators experimentally removed or retained. We also observe pollinator behaviors in the plots and experimental arrays. During flowering, pollinators significantly changed the effect of Clarkia interactions on seed success in 31% of species interactions, and these changes corresponded to pollinator behaviors. Whole-plant fecundity, however, did not depend on interactions between Clarkia; instead, non-Clarkia forbs that grew earlier in the season limited fecundity, constituting a priority effect during vegetative growth. Our study shows that interactions during vegetative growth can preclude the effect of pollinator-mediated interactions on fecundity by limiting potential reproductive output, and that simultaneously studying different modes of interaction allows for understanding the contingency of ecological outcomes.

Experimental study of the differentiation of gabbro-syenite melt under superliquidus conditions

ABSTRACT In this work we present the results of experimental interaction of gabbro-syenite melt, corresponding to the average composition of Northern Timan rocks, with a complex hydrogen-containing fluid. The composition of the magmatic fluid was controlled to be close to natural conditions using a special cell in a high gas-pressure vessel. Under superliquidus conditions, the initial melt exsolves into melts of different composition, forming contrast, cryptic, and rhythmic melt stratifications. The experimental results agree with natural data in the petrochemical diagram. It follows from our experimental data that fluid-saturated melts in magmatic chambers are completely differentiated in the liquid state. In the absence of temperature gradients in the magma, gravitational migration of nanoclusters of different densities forms flotation, sedimentation, and rhythmic types of melt stratification. Transmission electron microscopy of the glasses formed in the cell was used to study the formation of nanoclusters in a fluid-saturated superliquidus anorthosite-granite model melt. Clusters with a size of 6 nm consist of a pseudo-crystalline anorthite core surrounded by fluid-saturated shells of the melt. The migration of fluid and fluid-enriched clusters to the upper part of the magmatic chamber results in the activation, from bottom to top, of the processes of crystallization in the magma.

Xe⋯OCS: relatively straightforward?

Spectroscopy meets theory in a study of Xe⋯OCS complex: accurate near-equilibrium structures, experimental interaction energies, and CCSD(T)/CBS results presented.

Robotics facial expression of anger in collaborative human–robot interaction

The facial expression of angry emotion can be useful to direct the interaction between agents, especially in unclear and cluttered environments. During the presence of an angry face, a process of analysis and diagnosis is activated in the subject that notices it, which could impact its behavior toward the one who expresses the emotion. In order to study such an effect in human–robot interaction, an expressive robotics face was designed and constructed. The influence of this face on human action and attention was analyzed in two collaborative tasks. Results of a digital survey, experimental interaction, and a questionnaire indicated that anger is the best recognized universal facial expression, has a regulatory effect in human action, and induces human attention when an unclear condition arises during the task. An additional finding was that the prolonged presence of an angry face reduces its impact compared to positive expressions.

Intermolecular interactions in crystals of small unsubstituted cyclic ethers and substituted epoxides

CE-B3LYP model energies are used to investigate intermolecular interactions in crystals of the relatively weakly bound cyclic ethers, as well as a number of substituted epoxides that have been the focus of high-quality experimental electron density studies. This approach readily provides a complete picture of all intermolecular interactions in these molecular crystals, and CE-B3LYP lattice energies for the unsubstituted cyclic ethers are in excellent agreement with available thermodynamic data. When compared with the outcomes of multipole modelling of X-ray diffraction data, these results suggest that experimental interaction energies are typically underestimated and, contrarily, experimental lattice energies are typically overestimated. These observations deserve careful investigation.

PECULIARITIES OF IDENTIFICATION STUDIES INTO WHETHER A FIRED 7.62x39 CALIBER BULLET AND CASE BELONG TO THE SAME CARTIDGE

Based on experimental research, the article determines the peculiarities of the impact trace formation mechanism on the external surfaces of the bullet and on the internal surfaces of the case mouths in 7.62*39 caliber intermediate cartridges. The article determines the influence of the case mouth crimp on the properties of the abovementioned traces, it also provides peculiarities of undertaking identification studies to establish whether the bullet and case belong to the same cartridge of the given caliber. It suggests using a special shell to reproduce experimental interaction traces and the way of its application, it allowed to obtain a solid identifiable microrelief on the surfaces of experimental samples. The article suggests the most suitable material for this type of a shell capable of reproducing traces. This kind of studies do not require special equipment and involvement of highly qualified specialists, experiments are prepared and conducted only with the use of available resources and common equipment. The suggested method can be applied for relevant traceological studies of material objects with curved contact surfaces that interacted with each other.