A model to investigate the mechanisms underlying the emergence and development of independent sitting

When infants first begin to sit independently, they are highly unstable and unable to maintain upright sitting posture for more than a few seconds. Over the course of 3 months, the sitting ability of infants drastically improves. To investigate the mechanisms controlling the development of sitting posture, a single‐degree‐of‐freedom inverted pendulum model was developed. Passive muscle properties were modeled with a stiffness and damping term, while active neurological control was modeled with a time‐delayed proportional‐integral‐derivative (PID) controller. The findings of the simulations suggest that infants primarily utilize passive muscle stiffness to remain upright when they first begin to sit. This passive control mechanism allows the infant to remain upright so that active feedback control mechanisms can develop. The emergence of active control mechanisms allows infants to integrate sensory information into their movements so that they can exhibit more adaptive sitting.     

The future of workplace commitment: key questions and directions

This position paper presents the state-of-the art of the field of workplace commitment. Yet, for workplace commitment to stay relevant, it is necessary to look beyond current practice and to extrapolate trends to envision what will be needed in future research. Therefore, the aim of this paper is twofold, first, to consolidate our current understanding of workplace commitment in contemporary work settings and, second, to look into the future by identifying and discussing avenues for future research. Representative of the changing nature of work, we explicitly conceptualize workplace commitment in reference to (A) “Temporary work”, and (B) “Cross-boundary work”. Progressing from these two themes, conceptual, theoretical and methodological advances of the field are discussed. The result is the identification of 10 key paths of research to pursues, a shared agenda for the most promising and needed directions for future research and recommendations for how these will translate into practice.     

Individual,Interpersonal, and Sociostructural Factors Influencing Partner Nonmonogamy Acceptance among Young African American Women

In 2015 in the United States, the HIV diagnosis rate among African American women was 16 times that of White women, and HIV especially affected young African American women. African American women’s partnerships with nonmonogamous men may be one factor contributing to this disparity. Previous research has not adequately described factors influencing acceptance of partner nonmonogamy among African American women. To better understand this phenomenon, we interviewed 11 African American women aged 18–24 years-old who reported having sex in the past 3 months and reported knowing or suspecting a partner to have another female partner in the past 12 months. We employed a semi-structured interview guide designed to elicit in-depth, narrative responses from women about their partnerships. We used narrative analysis to interpret findings. Participants described factors that encouraged acceptance of partner nonmonogamy. These factors were social (i.e., limited partner availability, gender norms, and cultural norms), interpersonal (i.e., partner-specific comfort, sexual connection and emotional attachment, and casual partnership type), and intrapersonal (i.e., low self-esteem, loneliness, and fatalistic attitudes about nonmonogamy) in nature. The sociocultural context in which young African American women develop sexual partnerships may influence their attitudes, expectations, and behaviors within these partnerships and place them at increased risk for HIV and other sexually transmitted infections.     

NEUROBEHAVIORAL SEQUELAE OF CHILD SEXUAL ABUSE

This study examined intellectual and memory functioning in a sample of sexually abused children compared to demographically and age-matched controls. The severity of abuse and other pertinent factors were also examined in relation to cognitive performance. Elevated levels of psychopathology were present in the abused children, as well as diminished performance on tasks influenced by attention/concentration. However, after controlling for differences in IQ and socioeconomic status (SES), significant differences in memory function were not found. Results are discussed in the context of stress effects on cognition and the potential resiliency of cognitive function in children undergoing treatment for sexual abuse.     

Reviews

He Leadeth Me by Walter J. Ciszek, S.J., with Daniel Flaherty, S.J. Hodder and Stoughton, London, 1974. 216 pp., £2.50.

Miracle in Moscow by David Benson, Miracle Publications, Santa Barbara, 1973. 290 pp.

Vanya by Myrna Grant, Creation House, Illinois, 1974. 222 pp. $4.95.

Church, State and Opposition in the USSR by Gerhard Simon, C. Hurst & Co., London, 1974. 248 pp., £4.20.