scholarly journals The Artificial Cell, the Semipermeable Membrane, and the Life that Never Was, 1864–1901

2019 ◽  
Vol 49 (5) ◽  
pp. 504-555 ◽  
Author(s):  
Daniel Liu
Keyword(s):  
Physical Chemistry ◽  
Cell Membrane ◽  
Physical Sciences ◽  
Early Nineteenth Century ◽  
Modern Biology ◽  
Artificial Cell ◽  
Plant Physiologist ◽  
Cultural Terms ◽  
Marginal Status ◽  
Definition Of

Since the early nineteenth century, a membrane or wall has been central to the cell’s identity as the elementary unit of life. Yet the literally and metaphorically marginal status of the cell membrane made it the site of clashes over the definition of life and the proper way to study it. In this article I show how the modern cell membrane was conceived of by analogy to the first “artificial cell,” invented in 1864 by the chemist Moritz Traube (1826–1894), and reimagined by the plant physiologist Wilhelm Pfeffer (1845–1920) as a precision osmometer. Pfeffer’s artificial cell osmometer became the conceptual and empirical basis for the law of dilute solutions in physical chemistry, but his use of an artificial analogue to theorize the existence of the plasma membrane as distinct from the cell wall prompted debate over whether biology ought to be more closely unified with the physical sciences, or whether it must remain independent as the science of life. By examining how the histories of plant physiology and physical chemistry intertwined through the artificial cell, I argue that modern biology relocated vitality from protoplasmic living matter to non-living chemical substances—or, in broader cultural terms, that the disenchantment of life was accompanied by the (re)enchantment of ordinary matter.

MONARCHS, TRAVELLERS AND EMPIRE IN THE PACIFIC'S AGE OF REVOLUTIONS

2020 ◽  
Vol 30 ◽  
pp. 77-96
Author(s):  
Sujit Sivasundaram
Keyword(s):  
Pacific Islanders ◽  
Modern World ◽  
Global History ◽  
The Past ◽  
The Pacific ◽  
Cultural Terms ◽  
The Pacific Ocean ◽  
Definition Of ◽  
The Uk ◽  
A Site

AbstractThe Pacific has often been invisible in global histories written in the UK. Yet it has consistently been a site for contemplating the past and the future, even among Britons cast on its shores. In this lecture, I reconsider a critical moment of globalisation and empire, the ‘age of revolutions’ at the end of the eighteenth century and the start of the nineteenth century, by journeying with European voyagers to the Pacific Ocean. The lecture will point to what this age meant for Pacific islanders, in social, political and cultural terms. It works with a definition of the Pacific's age of revolutions as a surge of indigeneity met by a counter-revolutionary imperialism. What was involved in undertaking a European voyage changed in this era, even as one important expedition was interrupted by news from revolutionary Europe. Yet more fundamentally vocabularies and practices of monarchy were consolidated by islanders across the Pacific. This was followed by the outworkings of counter-revolutionary imperialism through agreements of alliance and alleged cessation. Such an argument allows me, for instance, to place the 1806 wreck of the Port-au-Prince within the Pacific's age of revolutions. This was an English ship used to raid French and Spanish targets in the Pacific, but which was stripped of its guns, iron, gunpowder and carronades by Tongans. To chart the trajectory from revolution and islander agency on to violence and empire is to appreciate the unsettled paths that gave rise to our modern world. This view foregrounds people who inhabited and travelled through the earth's oceanic frontiers. It is a global history from a specific place in the oceanic south, on the opposite side of the planet to Europe.

Bekenstein‐Hawking black hole entropy, Hawking temperature, and the Unruh effect: Insight from the laws of thermodynamics

2020 ◽  
Vol 33 (2) ◽  
pp. 143-148
Author(s):  
Stephen J. Crothers ◽  
Pierre-Marie Robitaille
Keyword(s):  
Black Hole ◽  
Scientific Inquiry ◽  
Black Hole Entropy ◽  
Universal Constant ◽  
Unruh Effect ◽  
Physical Sciences ◽  
Laws Of Thermodynamics ◽  
Large Systems ◽  
Definition Of ◽  
Schwarzschild Radius

The laws of thermodynamics play a central role in scientific inquiry, guiding physics as to the validity of hypothesized claims. It is for this reason that quantities of thermodynamic relevance must retain their character wherever they appear. Temperature, for example, must always be intensive, a requirement set by the 0th law. Otherwise, the very definition of temperature is compromised. Similarly, entropy must remain extensive, in order to conform to the second law. These rules must be observed whenever a system is large enough to be characterized by macroscopic quantities, such as volume or area. This explains why ensembles comprised of just a few atoms cannot be considered thermodynamic systems. In this regard, black holes are hypothesized to be large systems, characterized by the Schwarzschild radius (rs = 2GM/c 2) and its associated “horizon” area (A = 4πrs 2), where G, M, and c represent the universal constant of gravitation, the mass of the black hole, and the speed of light in vacuum, respectively. It can be readily demonstrated that Bekenstein‐Hawking black hole entropy is nonextensive, while the Hawking and the Unruh temperatures are nonintensive. As a result, the associated equations violate the laws of thermodynamics and can hold no place in the physical sciences.

WOMEN, MARGINALITY AND THE ZULU STATE: WOMEN'S INSTITUTIONS AND POWER IN THE EARLY NINETEENTH CENTURY

1998 ◽  
Vol 39 (3) ◽  
pp. 389-415 ◽  
Author(s):  
SEAN HANRETTA
Keyword(s):  
South Africa ◽  
Nineteenth Century ◽  
State Government ◽  
Gender Relations ◽  
Historical Change ◽  
Political Organization ◽  
Internal Conflict ◽  
Early Nineteenth Century ◽  
The Past ◽  
Definition Of

For a number of years the historiography of Southern Africa has been dominated by a materialist framework that has focused upon modes of production and forms of socio-political organization as the determining factors in historical change. Those historians concerned with the history of women in pre-colonial societies – even those who have privileged gender relations in their analyses – have largely been content to construct women's history by applying the insights of socio-economic and political analyses of the past to gender dynamics, and by projecting the insights of anthropological analyses of present gender relations into the past. Some of these historians have concluded that until the arrival of capitalism no substantial changes in the situations, power or status of women took place within Zulu society, even during the period of systemic transformation known as the mfecane in the early nineteenth century.More recently, Zulu gender history has become part of a larger debate connected to the changing political and academic milieu in South Africa. Representatives of a revived Africanist tradition have criticized materialist historians for writing Zulu history from an outsider's perspective and of focusing overly on conflict and power imbalances within the nineteenth-century kingdom in an effort to discredit contemporary Zulu nationalism. To counter this, historian Simon Maphalala has stressed the harmony of nineteenth-century Zulu society, the power advisors exercised in state government, and the lack of internal conflict. Maphalala also claims that women's subordinate role in society ‘did not cause any dissatisfaction among them’, and argues that ‘[women] accepted their position and were contented’. In recent constitutional debates many South African intellectuals including members of the Congress of Traditional Leaders of South Africa (CONTRALESA), invoked this ‘benign patriarchy’ model of pre-colonial gender relations to oppose the adoption of gender-equality provisions in the new constitution. As Cherryl Walker has noted, the hegemonic definition of traditional gender relations to which such figures have made rhetorical appeals often masks not only the historicity of these relations but also hides dissenting opinions (often demarcated along gender lines) as to what those relations are and have been.

scholarly journals Nanopore formation process in artificial cell membrane induced by plasma-generated reactive oxygen species

2016 ◽  
Vol 605 ◽  
pp. 26-33 ◽  
Author(s):  
Ryugo Tero ◽  
Ryuma Yamashita ◽  
Hiroshi Hashizume ◽  
Yoshiyuki Suda ◽  
Hirofumi Takikawa ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Membrane ◽  
Formation Process ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Artificial Cell

7AM2-C-7 DNA logic calculation using the membrane protein reconstituted artificial cell membrane

2013 ◽  
Vol 2013.5 (0) ◽  
pp. 251-252
Author(s):  
Kosuke INOUE ◽  
Ryuji KAWANO ◽  
Hiroki YASUGA ◽  
Masahiro TAKINOUE ◽  
Koki KAMIYA ◽  
...  
Keyword(s):  
Cell Membrane ◽  
Membrane Protein ◽  
Artificial Cell

Henry Bence-Jones, M. D. , F. R. S. (1813-1873)

1973 ◽  
Vol 28 (1) ◽  
pp. 31-56 ◽  
Keyword(s):  
Nineteenth Century ◽  
Diagnosis And Treatment ◽  
Animal Tissues ◽  
Physical Sciences ◽  
Early Nineteenth Century ◽  
Scientific Principles ◽  
Chemical Knowledge ◽  
The Subject ◽  
Living Organisms ◽  
To Receive

Many leading nineteenth-century physicians recognized the need to reduce the empirical element in medicine and to base both diagnosis and treatment more firmly upon scientific principles. In an age when chemistry was a rapidly developing science it seemed that animal chemistry, dealing with the materials and functions of living organisms, might well offer the best solution to the problem. Thus the development of the subject for medical purposes became one of the main objectives of animal chemists, although from hindsight it is clear that neither the techniques nor the chemical knowledge available were at all adequate for solving the complex problems involved. Yet chemists like Fourcroy and Berzelius tried to understand the chemistry of life and their results seemed to support the widely held view that a knowledge of the composition of animal tissues, together with an understanding of the natural functions in health, would aid medical diagnosis and treatment by exposing the faults present in disease. In early nineteenth-century England there was a lively interest in this subject (I) and some physicians became very successful in applying chemical principles to medicine, but despite the evident value of animal chemistry the novelty of the subject caused medical schools to be reluctant to introduce it into their curricula. Medical students continued to receive instruction in the classics but the physical sciences were frequently neglected.

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