Temporal control of behavior and the power law

The performance of rats and pigeons under fixed-interval schedules was studied in two experiments. The duration of postreinforcement pause was a declining proportion of fixed-interval duration. For pigeons this was true both when the duration of the reinforcer was fixed and when it was increased in direct proportion to increases in fixed-interval duration; the longer reinforcer durations did, however, lengthen the postreinforcement pause at higher schedule values. A quantitative analysis of data from Experiments 1 and 2 and from other studies showed that fractional exponent power functions described the relationship between postreinforcement pause and fixed-interval value; similar functions have previously been observed in studies of temporal differentiation. It was concluded that power functions reflect a direct causal, rather than artifactual, relationship between performance and the temporal requirements of reinforcement schedules.</p

Use of protein A-coated colloidal gold particles for immunoelectronmicroscopic localization of ACTH on ultrathin sections

ACTH was localized in dissociated porcine adenohypophysial cells using a novel indirect EM immunocytochemical technique. Incubation of ultrathin resin sections in anti-ACTH was followed by incubation with protein A-coated colloidal gold particles. Protein A binds specifically to the Fc part of the IgG molecule, and thus the ACTH-containing secretory granules became labelled with electron-dense gold particles. With this method, the dissociated porcine ACTH cells was identified as containing numerous round or ovoid 170--300 nm secretory granules.</p

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

Gender, relationships and desistance

This edited collection offers unique insight into the role and impact of relationships for women involved in the criminal justice system. Through drawing together academic research, lived experience and reflections of frontline perspectives, the collection interrogates the personal, public and professional themes of these relationships, broadening current analysis and calling for a reimagining of the future. Each author demonstrates the complexity of these themes with rich and powerful contributions that offer a crucial understanding into the complexity and nuance of this area. By connecting a range of perspectives and different forms of expression, this original collection extends and challenges current understanding and calls for reimaging and change

Linesman for the county:a case study of the implementation and management of a county line drugs distribution network.

This article explores the dynamics of mid-level drug distribution within the United Kingdom’s County Lines networks, drawing on qualitative research involving semi-structured interviews with individuals engaged in illicit drug markets. The analysis situates the lived experiences of mid-level distributors within broader sociological frameworks, including Bourdieu’s concept of habitus and Anderson’s Code of the Street, to interrogate how structural inequality, cultural capital, and criminal innovation converge in sustaining these networks. County Lines, characterised by the movement of drugs from urban hubs into rural and coastal communities, rely heavily on the exploitation of vulnerable individuals, often involving coercion, violence, and manipulation. This research highlights the critical role of mid-level actors who bridge the gap between street-level dealers and large-scale suppliers, and whose practices reflect a strategic yet chaotic enterprise model that mirrors—and distorts—legitimate business practices.Through empirical insights and first-person narratives, particularly that of “Albie,” the article reveals how tactics such as “taxing,” “cuckooing,” and kidnapping are deployed as mechanisms of control and economic advancement. The findings underscore the need to reconceptualise criminal culpability in these contexts, recognising the blurred boundaries between victimhood and offending. The study calls for nuanced policy responses that move beyond enforcement to address the socio-economic drivers of drug market involvement. By shedding light on the internal logics of County Lines networks, this research contributes to a deeper understanding of contemporary illicit drug economies and the evolving forms of criminal entrepreneurship in the UK.Keywords: County Lines, mid-level drug distribution, exploitation, street capital, qualitative research.<br/

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.