A Bitcoin-inspired infinite-server model with a random fluid limit

The synchronization process inherent to the Bitcoin network gives rise to an infinite-server model with the unusual feature that customers interact. Among the closed-form characteristics that we derive for this model is the busy period distribution which, counterintuitively, does not depend on the arrival rate. We explain this by exploiting the equivalence between two specific service disciplines, which is also used to derive the model’s stationary distribution. Next to these closed-form results, the second major contribution concerns an asymptotic result: a fluid limit in the presence of service delays. Since fluid limits arise under scalings of the law-of-large-numbers type, they are usually deterministic, but in the setting of the model discussed in this paper the fluid limit is random (more specifically, of growth-collapse type).     

Trajectories of Limitations with Activities of Daily Living Among Older Adults of Mexican Descent: The Role of Widowhood

Using seven waves of data from the Hispanic Established Population for the Epidemiologic Study of the Elderly (1993–2011), this study applies multiphase growth models to examine changes in limitations with activities of daily living (ADL) across widowhood experience among 385 older adults of Mexican descent. This study also investigates the implications of demographic characteristics, health, socioeconomic status, living arrangements, and social involvement. ADL limitations increased pre-widowhood, were at higher levels immediately before and especially during the transition to widowhood, and increased at a steeper rate post-widowhood. Age and partially depressive symptoms accounted for these trends in ADL limitations pre-widowhood and to a lesser extent during the transition to widowhood and post-widowhood. Older age, being female, chronic conditions, financial strain, lower educational attainment, coresidence with children and others, and less frequent church attendance were risk factors for higher levels of and greater increases in these functional limitations throughout widowhood experience.     

“Thank You for Including Us!” – Introducing a Community‐Based Collaborative Approach to Translating Clinic Materials

When working with clients in another language, having culturally relevant and properly translated clinic materials is vital to effective clinical practice. Not having them presents a barrier for bilingual therapists and their clients. This paper reviews common translation methods and introduces a multi‐level, community‐based approach for translating clinic materials for non‐English speaking clients. Informed by decolonizing practices, this five‐tier method includes members from the target community as cultural brokers to verify the accuracy and nuances of language for their cultural group, as well as a constant comparative method to ensure methodological rigor in the process of inclusion. We present community member's feedback and recommendations, as well as discuss advantages and challenges of using this collaborative culturally responsive translation method.     

Maternal Postpartum Depression Increases Vulnerability for Toddler Behavior Problems through Infant Cortisol Reactivity

The current study examined the role of hypothalamic‐pituitary‐adrenal reactivity (a physiological indicator of stress) in early infancy as a mediator of the relationship between maternal postpartum depression and toddler behavior problems. Participants were 137 at‐risk mothers and their children participating in a longitudinal study of intergenerational transmission of risk. Mothers’ depression was measured five times during the infants’ first 18 months. Infant cortisol was collected during a social stressor (the still‐face paradigm) when infants were 6 months old, and mothers reported on toddlers’ internalizing and externalizing symptoms at 18 months. Among this sample of high‐risk mother–infant dyads, early postpartum depression predicted atypical infant cortisol reactivity at 6 months, which mediated the effect of maternal depression on increased toddler behavior problems. Clinical implications are discussed.     

Downsizing for downtown: limb lengths,toe lengths,and scale counts decrease with urbanization in western fence lizards (Sceloporus occidentalis)

Urban Ecosystems - Urbanization-induced habitat loss and alteration causes significant challenges for the survival of many species. Identifying how species respond to urbanization can yield...     

Effects of variations in water quantity and quality in the structure and functions of invertebrates’ community of a Mediterranean urban stream

Urban Ecosystems - Urban streams provide important ecosystem services to cities’ population, from the maintenance of urban biodiversity, temperature, humidity and air quality to improving...     

Urban ecosystem Services in Latin America: mismatch between global concepts and regional realities?

Urban Ecosystems - Latin America and the Caribbean (LAC) is one of the most urbanized and biologically diverse regions in the world but is often characterized by weak environmental governance and...     

A critical approach to wage devaluation: The case of Spanish economic recovery

In line with the orientation of EU economic policy, the Spanish government has favoured a strategy of internal devaluation as a way of adjusting price levels within the currency union. The results of empirical studies indicate that the internal devaluation applied in Spain does not seem to have attained the desired goals in terms of reducing the relative prices of exports and consolidating a model of growth based on external demand. Indeed, the estimates drawn up show that tailwinds – the depreciation of the euro and the fall in risk premium as results of the measures taken by the ECB, greater economic activity by trading partners and the fall in the price of oil – exercised a decisive influence in the trends followed by the prices of exports and the balance of trade during the period of crisis management in Spain.     

M&A and diversification strategies: what effect on quality of inventive activity?

Journal of Management and Governance - The aim of this paper is to examine how an acquirer’s diversification strategy shapes the multiple dimensions of inventive activity. Differing from...     

Altruism, Spite and Competition in Bargaining Games

This paper shows that altruism may be beneficial in bargaining when there is competition for bargaining partners. In a game with random proposers, the most altruistic player has the highest material payoff if players are sufficiently patient. However, this advantage is eroded as the discount factor increases, and if players are perfectly patient altruism and spite become irrelevant for material payoffs.