Prdm1 (Blimp-1) and the Expression of Fast and Slow Myosin Heavy Chain Isoforms during Avian Myogenesis In Vitro

BACKGROUND. Multiple types of fast and slow skeletal muscle fibers form during early embryogenesis in vertebrates. In zebrafish, formation of the earliest slow myofibers in fin muscles requires expression of the zinc-finger transcriptional repressor Prdm1 (also known as Blimp1). To further understand how the role of Prdm1 in early myogenesis may vary through evolution and during development, we have now analyzed Prdm1 expression in the diverse types of myotubes that form in culture from somitic, embryonic, and fetal chicken myoblasts. PRINCIPAL FINDINGS. In cultures of somitic, embryonic limb, and fetal limb chicken cells, we found that Prdm1 was expressed in all of the differentiated muscle cells that formed, including those that expressed only fast myosin heavy chain isoforms, as well as those that co-expressed both fast and slow myosin heavy chain isoforms. Prdm1 was also expressed in Pax7-positive myoblasts, as well as in non-myogenic cells in the cultures. Furthermore, though all differentiated cells in control somite cultures co-expressed fast and slow myosin heavy chains, antisense knockdown of Prdm1 expression inhibited the formation of these co-expressing cells in somite cultures. CONCLUSIONS. In chicken myogenic cell cultures, Prdm1 was expressed in most Pax7-positive myoblasts and in all differentiated muscle cells, irrespective of the developmental stage of cell donor or the pattern of fast and slow myosin heavy chains expressed in the differentiated cells that were formed. Thus, Prdm1 was expressed in myogenic cells prior to terminal differentiation; and, after differentiation, Prdm1 expression was not limited to cells that expressed slow myosin heavy chain isoforms. In addition, Prdm1 appeared to be required for differentiation of the somitic myocytes, which are the earliest myocytes to form in the avian embryo.National Research Initiative of the United States Department of Agriculture Cooperative State Research, Education, and Extension Service (#2006-35206-16622); National Heart, Lung, and Blood Institute (2R01HL064641

Correlates of Wisdom

Although wisdom has always played a prominent role in philosophy and religion, contemporary empirical wisdom research started around 1980, when several research teams tried to determine what wisdom is and how it can be measured. Two different approaches emerged, divided into implicit and explicit theories of wisdom. The implicit approach asked lay people to name characteristics of wise individuals that were then summarized into several dimensions, while the explicit approach referred to experts and classical wisdom texts to define the essential elements of wisdom. Based on these implicit and explicit wisdom theories, several wisdom measures have been developed in the past decades, ranging from measures that assess the cognitive aspects of general wisdom-related knowledge to those that attempt to capture the noncognitive elements of personal wisdom. Not surprisingly, correlates of wisdom vary, depending on what kind and what aspects of wisdom are assessed. Wisdom measures are distinguished on three dimensions: whether the measure assesses general or personal wisdom, whether cognitive or noncognitive aspects of wisdom are emphasized, and whether a rating measure or a standardized scale is used to assess wisdom

Theories of Wisdom and Aging

What is wisdom and does it come with age as many people assume, or is it a relatively rare quality even among the older population? How do people develop wisdom throughout life and what might be its benefits in old age? Empirical evidence suggests that wisdom in old age is positively related to subjective well-being and less fear of death, even in the face of physical disability or the nearing of death (Ardelt, Landes, Gerlach, & Fox, 2013). In fact, it appears that wisdom is most beneficial for subjective well-being under conditions of adversity and stress, when external means to increase well-being are less available (Ardelt, 2005; Ardelt & Edwards, in press). Wisdom tends to provide a sense of mastery and meaning in life that sustains well-being even under adverse circumstances (Etezadi & Pushkar, 2013; Glück & Bluck, 2013). In this chapter, we first provide a brief summary of explicit and implicit wisdom theories. After examining the relation between wisdom and age, we shed light on the contextual life-course approach to address the divergent trajectories of personal wisdom development, with focus on the importance of social support networks and role models. Last, we explore the associations among wisdom and culture, religion/spirituality, and well-being in old age

Pathways to Retirement in Taiwan: Do Ethnicity and Cohort Matter?

Studies about retirement often neglect ethnic identity. This research utilized the “Taiwan Longitudinal Study in Aging” data from 1989 to 1996 when political and social changes in the country occurred to examine the influence of ethnicity (dominant Mainlanders versus Southern Min, Hakka, and various indigenous people) on Taiwanese men’s working status at age 60 and above. We asked three questions: (1) Are Mainlanders more likely to retire earlier than non-Mainlanders? (2) Does working in the public versus the private sector affect the age of retirement and does this differ by ethnicity? (3)What factors determine retirement ages of two cohorts? Using chi-square and t-tests, results of a comparison of two cohorts (n = 1254 and n = 526 for the 1989 and 1996 cohorts, respectively) showed that being a Mainlander, being unmarried, older age, self-reported poor health, and functional limitation were associated with a higher likelihood of earlier retirement. In logistic regression models, public sector work mediated and moderated the effect of ethnicity on the likelihood of earlier retirement only in the older cohort, where Mainlander public sector workers had the greatest likelihood of earlier retirement, indicating that the incentive structure of public pensions contributes to earlier retirement. The results are consistent with cumulative advantage theory. To delay the retirement age for public sector workers, policymakers could reduce public pension incentives

Towards Intrinsic Molecular Communication Using Isotopic Isomerism

In this paper we introduce a new approach for molecular communication (MC). The proposed method uses isotopomers as symbols in a communication scenario, and we name this approach isotopic molecular communication (IMC). We propose a modulation scheme based on isotopic isomerism, where symbols are encoded via isotopes in molecules. This can be advantageous in applications where the communication has to be independent from chemical molecular concentration. Application scenarios include nano communications with isotopes in a macroscopic environment, i.e. encoding freshwater flow of rivers or drinking water utilities, or medical applications where blood carries isotopomers used for communication in a human or animal body. We simulate the capacity of communication in the sense of symbols per second and maximum symbol rate for different applications. We provide estimations for the symbol rate per distance and we demonstrate the feasibility to identify isotopes reliably. In summary, this isotopic molecular communication is a new paradigm for data transfer independent from molecular concentrations and chemical reactions, and can provide higher throughput than ordinary molecular communications

Daughter\u27s Generation: The Importance of Having Daughters Living Nearby for Older Korean Immigrants\u27 Mental Health

With declining adherence to filial piety in East Asian cultures, the closeness of adult daughters rather than sons may become more important for older Asian immigrants’ well-being. With a sample of 177 older Korean immigrants to the United States (age 60+, M = 72, SD = 7.7), we examined how and to what extent having daughters living nearby rather than sons (daughters-in-law) is related to older Asian immigrants’ mental health, moderating the direct relationship between stressful life events and depressive symptoms. The analyses showed physical proximity of daughters rather than sons (daughters-in-law) functioned as a stress buffer by reducing the direct relation between stressful life events and older immigrants’ depressive symptoms. The findings suggest that gendered cultural expectations of adult children’s caregiving roles for older Korean immigrants are changing, implying that companionship and the perceived quality of instrumental and emotional support might take priority over traditional gendered expectations of filial piety