The Proterozoic Record of Eukaryotes

Paleobiology ◽  
2015 ◽  
Vol 41 (4) ◽  
pp. 610-632 ◽  
Author(s):  
Phoebe A. Cohen ◽  
Francis A. Macdonald
Keyword(s):  
Large Scale ◽  
Snowball Earth ◽  
Geographic Variability ◽  
The Past ◽  
Past Half Century ◽  
Age Constraints ◽  
Composition Changes ◽  
Current Record ◽  
Past Half ◽  
Early Neoproterozoic

AbstractProterozoic strata host evidence of global “Snowball Earth” glaciations, large perturbations to the carbon cycle, proposed changes in the redox state of oceans, the diversification of microscopic eukaryotes, and the rise of metazoans. Over the past half century, the number of fossils described from Proterozoic rocks has increased exponentially. These discoveries have occurred alongside an increased understanding of the Proterozoic Earth system and the geological context of fossil occurrences, including improved age constraints. However, the evaluation of relationships between Proterozoic environmental change and fossil diversity has been hampered by several factors, particularly lithological and taphonomic biases. Here we compile and analyze the current record of eukaryotic fossils in Proterozoic strata to assess the effect of biases and better constrain diversity through time. Our results show that mean within assemblage diversity increases through the Proterozoic Eon due to an increase in high diversity assemblages, and that this trend is robust to various external factors including lithology and paleogeographic location. In addition, assemblage composition changes dramatically through time. Most notably, robust recalcitrant taxa appear in the early Neoproterozoic Era, only to disappear by the beginning of the Ediacaran Period. Within assemblage diversity is significantly lower in the Cryogenian Period than in the preceding and following intervals, but the short duration of the nonglacial interlude and unusual depositional conditions may present additional biases. In general, large scale patterns of diversity are robust while smaller scale patterns are difficult to discern through the lens of lithological, taphonomic, and geographic variability.

EDITORIAL: Migration and competitiveness: Japan and the United States

2013 ◽  
Vol 10 (2) ◽  
pp. 115-124
Author(s):  
Philip L. Martin
Keyword(s):  
United States ◽  
The United States ◽  
Variable Cost ◽  
Fixed Cost ◽  
Special Issue ◽  
Science And Engineering ◽  
The Past ◽  
Past Half Century ◽  
Key Sectors ◽  
Past Half

Japan and the United States, the world’s largest economies for most of the past half century, have very different immigration policies. Japan is the G7 economy most closed to immigrants, while the United States is the large economy most open to immigrants. Both Japan and the United States are debating how immigrants are and can con-tribute to the competitiveness of their economies in the 21st centuries. The papers in this special issue review the employment of and impacts of immigrants in some of the key sectors of the Japanese and US economies, including agriculture, health care, science and engineering, and construction and manufacturing. For example, in Japanese agriculture migrant trainees are a fixed cost to farmers during the three years they are in Japan, while US farmers who hire mostly unauthorized migrants hire and lay off workers as needed, making labour a variable cost.

Reframing the Sciences of the Long Eighteenth Century

2020 ◽  
Vol 50 (1-2) ◽  
pp. 58-66
Author(s):  
Giuliano Pancaldi
Keyword(s):  
Eighteenth Century ◽  
History Of Science ◽  
Science Policy ◽  
Special Issue ◽  
Half Century ◽  
The Past ◽  
Past Half Century ◽  
History Of ◽  
Long Eighteenth Century ◽  
Past Half

Here I survey a sample of the essays and reviews on the sciences of the long eighteenth century published in this journal since it was founded in 1969. The connecting thread is some historiographic reflections on the role that disciplines—in both the sciences we study and the fields we practice—have played in the development of the history of science over the past half century. I argue that, as far as disciplines are concerned, we now find ourselves a bit closer to a situation described in our studies of the long eighteenth century than we were fifty years ago. This should both favor our understanding of that period and, hopefully, make the historical studies that explore it more relevant to present-day developments and science policy. This essay is part of a special issue entitled “Looking Backward, Looking Forward: HSNS at 50,” edited by Erika Lorraine Milam.

Pakistan’s Development: Successes, Failures, and Future Tasks (Presidential Remarks)

1997 ◽  
Vol 36 (4I) ◽  
pp. 321-331
Author(s):  
Sarfraz Khan Qureshi
Keyword(s):  
Indian Subcontinent ◽  
General Meeting ◽  
The Past ◽  
Past Half Century ◽  
The Social ◽  
The Subject ◽  
Golden Jubilee ◽  
Freedom Movement ◽  
Past Half ◽  
Do So

It is an honour for me as President of the Pakistan Society of Development Economists to welcome you to the 13th Annual General Meeting and Conference of the Society. I consider it a great privilege to do so as this Meeting coincides with the Golden Jubilee celebrations of the state of Pakistan, a state which emerged on the map of the postwar world as a result of the Muslim freedom movement in the Indian Subcontinent. Fifty years to the date, we have been jubilant about it, and both as citizens of Pakistan and professionals in the social sciences we have also been thoughtful about it. We are trying to see what development has meant in Pakistan in the past half century. As there are so many dimensions that the subject has now come to have since its rather simplistic beginnings, we thought the Golden Jubilee of Pakistan to be an appropriate occasion for such stock-taking.

A Scientific Search for Altruism

2018 ◽  
Author(s):  
C. Daniel Batson
Keyword(s):  
Human Nature ◽  
Scientific Method ◽  
Laboratory Experiments ◽  
Fundamental Question ◽  
Empathic Concern ◽  
Altruistic Motivation ◽  
The Past ◽  
Past Half Century ◽  
Series Of Experiments ◽  
Past Half

This book provides an example of how the scientific method can be used to address a fundamental question about human nature. For centuries—indeed for millennia—the egoism–altruism debate has echoed through Western thought. Egoism says that the motivation for everything we do, including all of our seemingly selfless acts of care for others, is to gain one or another self-benefit. Altruism, while not denying the force of self-benefit, says that under certain circumstances we can care for others for their sakes, not our own. Over the past half-century, social psychologists have turned to laboratory experiments to provide a scientific resolution of this human nature debate. The experiments focused on the possibility that empathic concern—other-oriented emotion elicited by and congruent with the perceived welfare of someone in need—produces altruistic motivation to remove that need. With carefully constructed experimental designs, these psychologists have tested the nature of the motivation produced by empathic concern, determining whether it is egoistic or altruistic. This series of experiments has provided an answer to a fundamental question about what makes us tick. Framed as a detective story, the book traces this scientific search for altruism through the numerous twists and turns that led to the conclusion that empathy-induced altruism is indeed part of our nature. It then examines the implications of this conclusion—negative implications as well as positive—both for our understanding of who we are as humans and for how we might create a more humane society.

The Twentysomething Soul

2019 ◽  
Author(s):  
Tim Clydesdale ◽  
Kathleen Garces-Foley
Keyword(s):  
Young Adults ◽  
Religious Commitment ◽  
Religion And Spirituality ◽  
Lost Generation ◽  
Full Spectrum ◽  
Half Century ◽  
The Past ◽  
Past Half Century ◽  
Past Half ◽  
The Way

Few realize how much Americans’ journey through their twenties has changed during the past half-century or understand how incorrect popular assumptions about young adults’ religious, spiritual, and secular lives are. Today’s twentysomethings have been labelled the “lost generation”—for their presumed inability to identify and lead fulfilling lives, “kidults”—for their alleged refusal to “grow up” and accept adult responsibilities, and the “least religious generation”—for their purported disinterest in religion and spirituality. These characterizations are not only unflattering, they are deeply flawed. The Twentysomething Soul tells an optimistic story about American twentysomethings. Drawing on hundreds of interviews and a survey of thousands across America, it introduces readers to the full spectrum of American young adults, many of whom live purposefully, responsibly, and reflectively. Some prioritize faith and spirituality. Others reject their childhood religion to explore alternatives and practice a personal spirituality. Still others sideline religion and spirituality until their lives get settled or reject organized religion completely. There is change occurring in the religious and spiritual lives of young adults, but little of it is among the 1 in 4 American twentysomethings who have consistently prioritized religious commitment during the past half-century. The change is rather among the now 3 in 10 young adults who, though intentionally unaffiliated with religion, affirm a variety of religious, spiritual, and secular beliefs. The Twentysomething Soul will change the way readers view contemporary young adults, giving an accurate—and refreshing—understanding of their religious, spiritual, and secular lives.

Oxford Studies in Philosophy of Religion Volume 9

2019 ◽  
Keyword(s):  
Philosophy Of Science ◽  
Philosophy Of Language ◽  
Philosophy Of Religion ◽  
Half Century ◽  
The Past ◽  
Past Half Century ◽  
Inclusive Approach ◽  
Past Half

This is the ninth volume of Oxford Studies in Philosophy of Religion. As with earlier volumes, these essays follow the tradition of providing a non-sectarian and non-partisan snapshot of the subdiscipline of philosophy of religion. This subdiscipline has become an increasingly important one within philosophy over the last century, and especially over the past half century, having emerged as an identifiable subfield with this timeframe along with other emerging subfields such as the philosophy of science and the philosophy of language. This volume continues the initial intention behind the series of attracting the best work from the premier philosophers of religion, as well as including work by top philosophers outside this area when their work and interests intersect with issues in the philosophy of religion. This inclusive approach to the series provides an opportunity to mitigate some of the costs of greater specialization in our discipline, while at the same time inviting wider interest in the work being done in the philosophy of religion.

Some new maxims of chancery: ‘Explicated for the more facile introduction of such as are studiously addicted to that noble profession’†

2021 ◽  
Author(s):  
Sham Qayyum
Keyword(s):  
Stage I ◽  
Half Century ◽  
The Past ◽  
Teaching Aid ◽  
Past Half Century ◽  
Past Half

Abstract Over the past half century, the trust has undergone momentous change. A generation of Chancery practitioners reduced it from being a doctrine to a loophole. What, perhaps, many did not realise was that the changes would mostly be for the worse. Before explaining which aspects of the modern express trust trouble my conscience, I divide its history into Three Ages of the Trust. We now live in the Age of the Loophole Trust (1969–). To help us understand this latest stage, I utilise equity’s most venerable teaching aid – the maxim. My remarks are structured around three new (surreptitious) maxims.

scholarly journals Budgeting nitrogen flows and the food nitrogen footprint of Egypt during the past half century: Challenges and opportunities

2019 ◽  
Vol 130 ◽  
pp. 104895 ◽  
Author(s):  
Ahmed S. Elrys ◽  
Sajjad Raza ◽  
Ahmed I. Abdo ◽  
Zhanjun Liu ◽  
Zhujun Chen ◽  
...  
Keyword(s):  
Half Century ◽  
The Past ◽  
Past Half Century ◽  
Challenges And Opportunities ◽  
Past Half ◽  
Nitrogen Flows
Sign in / Sign up

Export Citation Format

Share Document