883 research outputs found
Book Review of Kenneth F. McCallion, Shoreham and the Rise and Fall of the Nuclear Power Industry
Review of Kenneth F. McCallion, Shoreham and the Rise and Fall of the Nuclear Power Industry (Praeger 1995). About the author, acknowledgements, foreword by Irving Like, index, preface, prologue, selected bibliography. LC 94- 32930; ISBN 0-275-94299-6 [221 pp. Cloth $55.00. 88 Post Road West, Westport CT 06881.
Marsupials and monotremes sort genome treasures from junk
A recent landmark paper demonstrates the unique contribution of marsupials and monotremes to comparative genome analysis, filling an evolutionary gap between the eutherian mammals (including humans) and more distant vertebrate species
Did sex chromosome turnover promote divergence of the major mammal groups?: De novo sex chromosomes and drastic rearrangements may have posed reproductive barriers between monotremes, marsupials and placental mammals
Comparative mapping and sequencing show that turnover of sex determining genes and chromosomes, and sex chromosome rearrangements, accompany speciation in many vertebrates. Here I review the evidence and propose that the evolution of therian mammals was precipitated by evolution of the male‐determining SRY gene, defining a novel XY sex chromosome pair, and interposing a reproductive barrier with the ancestral population of synapsid reptiles 190 million years ago (MYA). Divergence was reinforced by multiple translocations in monotreme sex chromosomes, the first of which supplied a novel sex determining gene. A sex chromosome‐autosome fusion may have separated eutherians (placental mammals) from marsupials 160 MYA. Another burst of sex chromosome change and speciation is occurring in rodents, precipitated by the degradation of the Y. And although primates have a more stable Y chromosome, it may be just a matter of time before the same fate overtakes our own lineage. Also watch the video abstract
Ethical dilemmas in clinical social work practice : how are social workers affected and how do we respond?
This mixed-methods exploratory research was undertaken to gain insight into how social workers perceive, are affected by, and respond to situations in which they are not able to enact social work ethics, or are asked to facilitate perceived injustice because of workplace restrictions. Seventy-four social workers responded to my online mixed methods survey. In quantitative responses, Likert scaled responses rated participants’ frequency and level of distress when encountering ethical dilemmas involving structural racism, classism, cultural insensitivity, sexism, heterosexism, protocols prioritizing funding over client care, protocols interfering with the treatment relationship, and protocols interfering with client self-determination. Participants also rated their sense of burnout related to structurally imposed ethical dilemmas. Both descriptive statistics were derived, and correlations were obtained between demographic information and quantitative response re: frequency and distress. Qualitative text boxes allowed descriptions of experiences with ethical dilemmas in more detail – e.g., information about roles and social work settings in which dilemmas took place, and descriptions of participants’ suffering and action in relation to dilemmas. The study opens new avenues for social work as a profession to explore in the interest of preserving its loyalty to the social work code of ethics, and the individual social workers’ well-being and professional satisfaction
THE DEVELOPMENT AND ANALYSIS OF A CLOSED SYSTEM OF VITRIFICATION FOR MAMMALIAN EMBRYOS
Embryo cryopreservation is an integral part of assisted reproduction because it allows for future use of these embryos. Cryopreservation occurs when there are supernumerary embryos or when an embryo transfer cannot be performed. There are two main methods to cryopreserve embryos. The most recent is vitrification, which uses high concentrations of cryoprotectants, a short time to cool and avoids ice crystals. The \u27gold standard\u27 is the slow-cool method, which uses low concentrations of cryoprotectants, a long time to cool embryos and produces extracellular ice crystals. Prior to introducing vitrification as part of the human cryopreservation regime, it is important that vitrification be evaluated through a research protocol using a mammalian embryo model. In this research, we used the two-cell, mouse embryo model to develop a closed system for vitrification, observe the toxicity of vitrification solutions, and compare blastocyst rates, pup rates and DNA damage between the vitrification and slow-cool method. Two commercially available devices were used to vitrify embryos. Both devices were studied as an open-system and a closed-system using two-cell and eight-cell mouse embryos. These devices and systems produced similar blastocyst rates. Two-cell mouse embryos were used for subsequent studies due to the increased potential to observe a detrimental effect with the earlier cell stage. A toxicity study demonstrated that two-cell mouse embryos, after remaining in vitrification solution for 32 minutes, produced fewer blastocysts than did two-cell mouse embryos that were removed from the vitrification solution at earlier time intervals (1, 2, 4, 8 and 16 minutes). However, when surviving blastocysts were transferred to recipients, they produced pups. Comparison studies between the vitrification and slow-cool method demonstrated that there were no significant differences in blastocyst rate, pup rate or percentage of normal embryos (not demonstrating DNA damage). In conclusion, a closed system was developed to vitrify two-cell mouse embryos. The toxicity of vitrification solutions were observed and the comparison of vitrification and slow-cool methods using blastocyst rate, pup rate and DNA damage as determinants showed that both methods were similar
Effects of Modified Schema-Based Instruction on Mathematical Percentage Calculation for Students with Extensive Support Needs in an IPSE Program
Effects of Modified Schema-Based Instruction on Mathematical Percentage Calculation for Students with Extensive Support Needs in an IPSE Progra
Higher education decisions and macroeconomic conditions at age eighteen
Using individual data from PIAAC and data on youth unemployment for 18 countries, we test how macroeconomic conditions experienced at age eighteen affect the following decisions in post-secondary and tertiary education: (i) enrollment (ii) dropping-out, (iii) type of degree completed, (iv) area of specialization, and (v) time-to-degree. We also analyze how the effects vary by gender and parental background. Our findings differ across geographies (Anglo-Saxon, Southern European, Western European, and Scandinavian countries), which shows that the impacts of macroeconomic conditions on higher education decisions depend on context, such as labor markets and education systems. By analyzing various components of higher education together, we are able to obtain a clearer picture of how during economic downturns potential mechanisms interact to determine higher education decisionsFinancial support from the Spanish Ministry of Science and Innovation (Grants: ECO2017-82882-R and PID2020-112739GA-I00
Specializing in growing sectors: Wage returns and gender differences
Matching individual data with national statistics for eight high-income OECD countries, we test whether those who specialized in fields of study when related sectors were growing earn higher wages later in life. We estimate 2-3% higher hourly wages for these individuals compared to others of similar characteristics and abilities who made their specialization choices under comparable macroeconomic conditions but when related sectors were not growing. We then test for heterogeneity in both who chooses fields of study associated with growing sectors, as well as in the wage impacts of doing so. We find that men are less likely to specialize in growing fields because they avoid traditionally female fields that have grown more over recent decades (i.e. health care and education). While for men with at least a bachelor's degree, specializing in traditionally female fields is associated with lower wages, this is not the case for men with vocational degrees, for whom non-wage factors must drive their reluctance towards female fields. Countries where men are less likely to specialize in growing fields are characterized by more traditional gender norms but also larger reductions in gender wage gapsThis paper is part of a research project funded by the Fundación Ramón Areces within their 13th Social Science National Competition 2014. We also acknowledge
financial support from the Spanish Ministry of Science and Innovation (grant ECO2017-82882-R) as well as funding from Comunidad de Madrid (grant SI1-PJ1-2019-00326
Marsupials and monotremes sort genome treasures from junk
A recent landmark paper demonstrates the unique contribution of marsupials and monotremes to comparative genome analysis, filling an evolutionary gap between the eutherian mammals (including humans) and more distant vertebrate species
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