Worker policing by egg eating in the ponerine ant Pachycondyla inversa

We investigated worker policing by egg eating in the ponerine ant Pachycondyla inversa, a species with morphologically distinct queens and workers. Colonies were split into one half with the queen and one half without. Workers in queenless colony fragments started laying unfertilized male eggs after three weeks. Worker-laid eggs and queen-laid eggs were introduced into five other queenright colonies with a single queen and three colonies with multiple queens, and their fate was observed for 30 min. Significantly more worker-laid eggs (range of 35–62%, mean of 46%) than queen-laid eggs (range of 5–31%, mean of 15%) were eaten by workers in single-queen colonies, and the same trend was seen in multiple-queen colonies. This seems to be the first well-documented study of ants with a distinct caste polymorphism to show that workers kill worker-laid eggs in preference to queen-laid eggs. Chemical analyses showed that the surfaces of queen-laid and worker-laid eggs have different chemical profiles as a result of different relative proportions of several hydrocarbons. Such differences might provide the information necessary for differential treatment of eggs. One particular alkane, 3,11-dimeC27, was significantly more abundant on the surfaces of queen-laid eggs. This substance is also the most abundant compound on the cuticles of egg layers

Alternative reproductive strategies: a queen perspective in ants

Ant colonies are commonly thought to have a stable and simple family structure, with one or a few egg-laying queens and their worker daughters. However, recent genetic studies reveal that the identity of breeding queens can vary over time within colonies. In several species, some queens are apparently specialized to enter established colonies instead of initiating a new colony on their own. The previously overlooked occurrence of queen turnover within colonies has important consequences not only on the genetic structure and nature of kin conflict within colonies, but also on the evolution of social parasitism

Playing Multiple Positions: Student-Athlete Identity Salience and Conflict

Student-athletes enact dual roles, as students and athletes, and hold corresponding identities. The salience of these identities and conflict between them have implications for student-athlete wellness. The purpose of this study was to (a) gain insight into organizational and individual characteristics associated with identity salience, by examining student-athletes across universities; and (b) shed light on situations of identity salience and conflict for student-athletes. We conducted a survey study of student-athletes across 17 universities that captured both quantitative and qualitative data. Our results reveal a relationship between identity salience and individual performance (academic and athletic) and university ranking. Further, we found an interaction between athlete and student identity salience, such that identifying strongly as a student, athlete, both, or neither has implications for conflict. Finally, by unpacking situations of identity salience and conflict, we show similarities and differences across student-athletes’ experiences. This study has implications for universities and athletic departments

Evaluation of large-eddy simulations forced with mesoscale model output for a multi-week period during a measurement campaign

Large-eddy simulations (LESs) of a multi-week period during the HD(CP)2 (High-Definition Clouds and Precipitation for advancing Climate Prediction) Observational Prototype Experiment (HOPE) conducted in Germany are evaluated with respect to mean boundary layer quantities and turbulence statistics. Two LES models are used in a semi-idealized setup through forcing with mesoscale model output to account for the synoptic-scale conditions. Evaluation is performed based on the HOPE observations. The mean boundary layer characteristics like the boundary layer depth are in a principal agreement with observations. Simulating shallow-cumulus layers in agreement with the measurements poses a challenge for both LES models. Variance profiles agree satisfactorily with lidar measurements. The results depend on how the forcing data stemming from mesoscale model output are constructed. The mean boundary layer characteristics become less sensitive if the averaging domain for the forcing is large enough to filter out mesoscale fluctuations. © Author(s) 2017.BMBF/01LK1203BBMBF/01LK1203

Emotion Knowledge, Loneliness, Negative Social Experiences, and Internalizing Symptoms Among Low‐income Preschoolers

Children with poor emotion knowledge (EK) skills are at risk for externalizing problems; less is known about early internalizing behavior. We examined multiple facets of EK and social‐emotional experiences relevant for internalizing difficulties, including loneliness, victimization, and peer rejection, in Head Start preschoolers (N = 134; M = 60 months). Results based on multiple informants suggest that facets of EK are differentially related to negative social‐emotional experiences and internalizing behavior and that sex plays a moderating role. Behavioral EK was associated with self‐reported loneliness, victimization/rejection, and parent‐reported internalizing symptoms. Emotion recognition and expressive EK were related to self‐reported loneliness, and emotion situation knowledge was related to parent‐reported internalizing symptoms and negative peer nominations. Sex moderated many of these associations, suggesting that EK may operate differently for girls vs. boys in the preschool social context. Results are discussed with regard to the role of EK for social development and intervention implications.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/110878/1/sode12083.pd

First On-Sky High Contrast Imaging with an Apodizing Phase Plate

We present the first astronomical observations obtained with an Apodizing Phase Plate (APP). The plate is designed to suppress the stellar diffraction pattern by 5 magnitudes from 2-9 lambda/D over a 180 degree region. Stellar images were obtained in the M' band (4.85 microns) at the MMTO 6.5m telescope, with adaptive wavefront correction made with a deformable secondary mirror designed for low thermal background observations. The measured PSF shows a halo intensity of 0.1% of the stellar peak at 2 lambda/D (0.36 arcsec), tapering off as r^{-5/3} out to radius 9 lambda/D. Such a profile is consistent with residual errors predicted for servo lag in the AO system. We project a 5 sigma contrast limit, set by residual atmospheric fluctuations, of 10.2 magnitudes at 0.36 arcsec separation for a one hour exposure. This can be realised if static and quasi-static aberrations are removed by differential imaging, and is close to the sensitivity level set by thermal background photon noise for target stars with M'>3. The advantage of using the phase plate is the removal of speckle noise caused by the residuals in the diffraction pattern that remain after PSF subtraction. The APP gives higher sensitivity over the range 2-5 lambda/D compared to direct imaging techniques.Comment: 22 pages, 5 figures, 1 table, ApJ accepte

Discoveries and challenges en route to swinhoeisterol A

In this work, a full account of the authors’ synthetic studies is reported that culminated in the first synthesis of 13(14→8),14(8→7)diabeo‐steroid swinhoeisterol A as well as the related dankasterones A and B, 13(14→8)abeo‐steroids, and periconiastone A, a 13(14→8)abeo‐4,14‐cyclo‐steroid. Experiments are described in detail that provided further insight into the mechanism of the switchable radical framework reconstruction approach. By discussing failed strategies and tactics towards swinhoeisterol A, the successful route that also allowed an access to structurally closely related analogues, such as Δ22‐24‐epi‐swinhoeisterol A, is eventually presented