Helpers or halos: examining the evaluative mechanisms underlying selective prosociality.

This research examines the proximate evaluative mechanisms underlying prosocial partner choice-based reciprocity. Across four studies we presented 855 university undergraduates (online for course credit) and 76 4- to 6-year-olds (offline at a university laboratory) with vignettes describing prosocial, social and non-social characters, and asked participants about their person preferences in prosocial, social and general contexts. Adults demonstrated sophisticated appraisals, coordinating between relevant trait and contextual cues to make selections.

[Foliar water use efficiency of Platycladus orientalis sapling under different soil water contents].

The determination of plant foliar water use efficiency will be of great value to improve our understanding about mechanism of plant water consumption and provide important basis of regional forest ecosystem management and maintenance, thus, laboratory controlled experiments were carried out to obtain Platycladus orientalis sapling foliar water use efficiency under five different soil water contents, including instantaneous water use efficiency (WUE) derived from gas exchange and short-term water use efficiency (WUE) caculated using carbon isotope model. The results showed that, controlled by stomatal conductance (g), foliar net photosynthesis rate (P) and transpiration rate (T) increased as soil water content increased, which both reached maximum va-lues at soil water content of 70%-80% field capacity (FC), while WUE reached a maximum of 7.26 mmol·m·s at the lowest soil water content (35%-45% FC).