Climatic signals in British Isles tree-ring chronologies

Interpretation of proxy records of past environmental conditions derived from dated geological or biological materials is of great importance for the extension of the climatic record1,2. Precisely dated, replicated tree-ring series have been particularly useful as they provide records (usually ring-widths) dated to the individual year, for hundreds or thousands of years. Each such series, or chronology, is derived from a particular known location. Thus a network of such chronologies may be developed for a particular region and used as a proxy record of spatial and temporal climatic variations. This has been achieved in North America by Fritts et al.3,4, using principally chronologies from semi-arid areas or from near altitudinal or polar tree-lines. We report evidence here that tree-ring chronologies from sites in the British Isles will provide suitable proxy records for the reconstruction of historical temporal and spatial variation of climate

Temporal control of behavior:schedule interactions

In Experiment I the response that terminated the postreinforcement pauses occurring under a fixed-interval 60-second schedule was reinforced, if the pause duration exceeded 30 seconds. The percentage of such pauses, rather than increasing, decreased. There were complex effects on the discriminative control of the pause by the reinforcer terminating the previous fixed interval, depending on whether the fixed interval and the added reinforcer were the same or different. In Experiments II(a) and II(b), each reinforcement initiated an alternative fixed-interval interresponse-time-greater-than-t-sec schedule, the schedule values being systematically varied. When the response following a pause exceeding a given duration was reinforced, fewer such pauses occurred than when they were not reinforced, i.e., on the comparable simple fixed-interval schedule. There was no systematic relationship between mean interrinforcement interval and duration of the postreinforcement pause. The pause duration initiated by reinforcement was directly related to the dependency controlling the shortest pause at that time, regardless of changes in mean interreinforcement interval.</p

From stigma to strength?:the interrelations between sexual identity stigma, well-being, and accepting communities on Instagram amongst sexual minority youth

Initial evidence suggests that engaging with accepting communities on social media such as Instagram may inform sexual minority youths' sense of stigma and well-being. However, as existing research has predominately drawn upon cross-sectional or qualitative designs, it is currently unclear whether the positive experiences identified in previous research accumulate, endure, or evolve over time. We also know relatively little about whether engagement with accepting online communities is primarily a compensatory or enhancing behavior. Thus, drawing upon minority stress theory and broaden-and-build theory, this study explores the longitudinal reciprocal relationships between perceived stigma, well-being, and engagement with accepting Instagram communities. Three-wave panel data were collected from 460 sexual minority youth in the United States and Poland (M age = 18.58, SD = 1.64), and data were analyzed using a random intercept cross-lagged panel model. At the between-person level, engagement with accepting Instagram communities was positively associated with perceived stigma and negatively associated with well-being. No significant within-person associations emerged between perceived stigma and engagement with accepting Instagram networks. However, a positive reciprocal relationship was found between well-being and engagement with accepting Instagram communities. Cultural context had no moderating effect on the hypothesized model. Results suggest that whilst the interrelations between perceived stigma and engaging with accepting online networks may be short-lived, engaging with supportive Instagram communities may contribute to an upward spiral of positive emotions. Findings therefore extend the existing literature regarding the potential benefits of social media use amongst sexual minority youth. [Abstract copyright: © 2025 Foundation for Professionals in Services to Adolescents.