scholarly journals On the application of the theory of dissociation of Arrhenius electrolyte solutions to electrophysiology

2020 ◽  
Vol VI (1) ◽  
pp. 173-188
Author(s):  
V. Chagovets
Keyword(s):  
Direct Evidence ◽  
Practical Interest ◽  
Electrolyte Solutions ◽  
Past Century ◽  
Living Tissue ◽  
Physical Conditions ◽  
The Past ◽  
Satisfactory Answer ◽  
Living Tissues ◽  
Secondary Results

Some 150 years passed since the time when the idea was first expressed that the source of nervous power is electricity (Gausen, 1743). So much noise was overtaken in the past century by Mesmer's statements, which also explained how the special manifestation of electrical and magnetic forces, even more strengthened the faith, if not into identity, then) at least, into a close kinship of the energetic beginning of electricity. But, apart from abstract considerations, there was no direct evidence in support of these views in science. Only half a century later, after Gausen Galvani made his famous discovery that the muscles of a dissected frog's leg contract if the sciatic nerve and the lower part of it are connected with a metal conducting arc. Galvani, as is known, attributed this phenomenon to the presence of electrical forces generated in itself by the living tissue itself. But soon Volta arose against this view, who believed in this case the source of electricity not in the very tissues of the frog, but in the place of contact of the metal of the conducting arc with the liquid of living tissue. It was here that the beginning of that endless dispute was laid, which has been going on for a whole century and has not yet received a final solution, and which can be formulated as follows: does living protoplasm have independent sources of electric motor force, or does the electric phenomenon observed in living tissues only secondary results of the chemical or physical conditions that this tissue represents at a given moment, and do not have any direct connection with its functional activity? This question of enormous theoretical and practical interest, despite the mass of works of many outstanding scientists, has not yet received a satisfactory answer. Professor Biderman, in his extensive work on electrophysiology, which appeared last year, expresses himself on this matter as follows: the results of individual experiments and an almost complete lack of knowledge of the scope of their significance for the function of the underlying tissues. " (W. Biedermann. Elektrophysiologie. I. Abtheil. S. 273. Jena 1895).

scholarly journals Obituary notices of fellows deceased

1923 ◽  
Vol 104 (728) ◽  
Keyword(s):  
Private Schools ◽  
Practical Interest ◽  
Past Century ◽  
Personal Influence ◽  
The Past ◽  
Absorption Of Light ◽  
Keen Observer

Sir Norman Lockyer was the, last of the remarkable body of scientific men whose observations and discoveries in the past century provided the first steps to the present marvellous developments in physical astronomy. He was still a young man when Kirchhoff founded the science of astrophysics by his epoch-making experiment on the absorption of light by luminous gases, and he was one of the few who early realised what an enormous new field of investigation was thereby opened up. While still an amateur, he rapidly achieved a foremost place among the scientific men of his time, and for more than half a century devoted himself unceasingly to inquiries in which the spectroscope played a leading part. He was a keen observer and an imaginative thinker, and never hesitated in his speculations to run directly in opposition to the current ideas of his time if thereby he could explain more to his satisfaction the new facts which he was constantly bringing to light. He was a man of strong personality, and, apart from his own direct contribu­tions to science, he exerted a powerful personal influence for the benefit of science in many ways. He was gifted also with the power of lucid expression, and both as a lecturer and as a writer he succeeded in conveying to the lay mind a real comprehension of some of the most intricate features of the new astronomy. Joseph Norman Lockyer was born at Rugby on May 17, 1836. He was educated in various private schools and on the Continent, and appears to have acquired a taste for scientific pursuits from his father, who founded a scientific and literary society in Rugby and took a practical interest in the development of the electric telegraph. At the age of 21 he obtained a modest appointment in the War Office, and in 1865 his marked ability secured him the office of Editor of the Army Regulations. In subsequent years he was largely instrumental in placing Army legislation upon a more satisfactory basis.

scholarly journals Hyperthermal-driven mass extinctions: killing models during the Permian–Triassic mass extinction

2018 ◽  
Vol 376 (2130) ◽  
pp. 20170076 ◽  
Author(s):  
Michael J. Benton
Keyword(s):  
Direct Evidence ◽  
Rapid Heating ◽  
Large Igneous Province ◽  
Mass Extinctions ◽  
Depth Zone ◽  
Ambient Temperatures ◽  
Physical Conditions ◽  
The Past ◽  
Geological Past ◽  
Igneous Province

Many mass extinctions of life in the sea and on land have been attributed to geologically rapid heating, and in the case of the Permian–Triassic and others, driven by large igneous province volcanism. The Siberian Traps eruptions raised ambient temperatures to 35–40°C. A key question is how massive eruptions during these events, and others, could have killed life in the sea and on land; proposed killers are reviewed here. In the oceans, benthos and plankton were killed by anoxia–euxinia and lethal heating, respectively, and the habitable depth zone was massively reduced. On land, the combination of extreme heating and drought reduced the habitable land area, and acid rain stripped forests and soils. Physiological experiments show that some animals can adapt to temperature rises of a few degrees, and that some can survive short episodes of increases of 10°C. However, most plants and animals suffer major physiological damage at temperatures of 35–40°C. Studies of the effects of extreme physical conditions on modern organisms, as well as assumptions about rates of environmental change, give direct evidence of likely killing effects deriving from hyperthermals of the past. This article is part of a discussion meeting issue ‘Hyperthermals: rapid and extreme global warming in our geological past’.

The zoonotic potential of bat-borne coronaviruses

2020 ◽  
Vol 4 (4) ◽  
pp. 365-381
Author(s):  
Ny Anjara Fifi Ravelomanantsoa ◽  
Sarah Guth ◽  
Angelo Andrianiaina ◽  
Santino Andry ◽  
Anecia Gentles ◽  
...  
Keyword(s):  
Genetic Material ◽  
Field Research ◽  
Sympatric Species ◽  
Animal Origin ◽  
Mammalian Host ◽  
Past Century ◽  
The Past ◽  
Novel Host ◽  
Horseshoe Bat ◽  
Human Infections

Seven zoonoses — human infections of animal origin — have emerged from the Coronaviridae family in the past century, including three viruses responsible for significant human mortality (SARS-CoV, MERS-CoV, and SARS-CoV-2) in the past twenty years alone. These three viruses, in addition to two older CoV zoonoses (HCoV-229E and HCoV-NL63) are believed to be originally derived from wild bat reservoir species. We review the molecular biology of the bat-derived Alpha- and Betacoronavirus genera, highlighting features that contribute to their potential for cross-species emergence, including the use of well-conserved mammalian host cell machinery for cell entry and a unique capacity for adaptation to novel host environments after host switching. The adaptive capacity of coronaviruses largely results from their large genomes, which reduce the risk of deleterious mutational errors and facilitate range-expanding recombination events by offering heightened redundancy in essential genetic material. Large CoV genomes are made possible by the unique proofreading capacity encoded for their RNA-dependent polymerase. We find that bat-borne SARS-related coronaviruses in the subgenus Sarbecovirus, the source clade for SARS-CoV and SARS-CoV-2, present a particularly poignant pandemic threat, due to the extraordinary viral genetic diversity represented among several sympatric species of their horseshoe bat hosts. To date, Sarbecovirus surveillance has been almost entirely restricted to China. More vigorous field research efforts tracking the circulation of Sarbecoviruses specifically and Betacoronaviruses more generally is needed across a broader global range if we are to avoid future repeats of the COVID-19 pandemic.

PCSK9 inhibition for LDL lowering and beyond – implications for patients with peripheral artery disease

VASA ◽  
2018 ◽  
Vol 47 (3) ◽  
pp. 165-176 ◽  
Author(s):  
Katrin Gebauer ◽  
Holger Reinecke
Keyword(s):  
Cardiovascular Risk ◽  
Risk Reduction ◽  
Ldl Receptor ◽  
Density Lipoprotein ◽  
Past Century ◽  
Pcsk9 Inhibitors ◽  
Cardiovascular Risk Reduction ◽  
Simultaneous Application ◽  
The Past ◽  
Pcsk9 Inhibition

Abstract. Low-density lipoprotein cholesterol (LDL-C) has been proven to be a causal factor of atherosclerosis and, along with other triggers like inflammation, the most frequent reason for peripheral arterial disease. Moreover, a linear correlation between LDL-C concentration and cardiovascular outcome in high-risk patients could be established during the past century. After the development of statins, numerous randomized trials have shown the superiority for LDL-C reduction and hence the decrease in cardiovascular outcomes including mortality. Over the past decades it became evident that more intense LDL-C lowering, by either the use of highly potent statin supplements or by additional cholesterol absorption inhibitor application, accounted for an even more profound cardiovascular risk reduction. Proprotein convertase subtilisin/kexin type 9 (PCSK9), a serin protease with effect on the LDL receptor cycle leading to its degradation and therefore preventing continuing LDL-C clearance from the blood, is the target of a newly developed monoclonal antibody facilitating astounding LDL-C reduction far below to what has been set as target level by recent ESC/EAS guidelines in management of dyslipidaemias. Large randomized outcome trials including subjects with PAD so far have been able to prove significant and even more intense cardiovascular risk reduction via further LDL-C debasement on top of high-intensity statin medication. Another approach for LDL-C reduction is a silencing interfering RNA muting the translation of PCSK9 intracellularly. Moreover, PCSK9 concentrations are elevated in cells involved in plaque composition, so the potency of intracellular PCSK9 inhibition and therefore prevention or reversal of plaques may provide this mechanism of action on PCSK9 with additional beneficial effects on cells involved in plaque formation. Thus, simultaneous application of statins and PCSK9 inhibitors promise to reduce cardiovascular event burden by both LDL-C reduction and pleiotropic effects of both agents.

Archaeology in the Past Century

1901 ◽  
Vol 51 (1309supp) ◽  
pp. 20976-20977
Author(s):  
W. M. Flinders Petrje
Keyword(s):  
Past Century ◽  
The Past

Catholicism and Cosmopolitanism: the Confluence of Three Catholic Scholars and the Cosmopolitan Democrats on State Sovereignty and the Future of Global Governance

2016 ◽  
Vol 3 (2) ◽  
pp. 37-51
Author(s):  
Matthew Bagot
Keyword(s):  
Global Governance ◽  
State Sovereignty ◽  
Current Debate ◽  
Past Century ◽  
Jacques Maritain ◽  
The Past ◽  
Technological Advances ◽  
The Future ◽  
Cosmopolitan Democracy ◽  
Catholic Tradition

One of the central questions in international relations today is how we should conceive of state sovereignty. The notion of sovereignty—’supreme authority within a territory’, as Daniel Philpott defines it—emerged after the Treaty of Westphalia in 1648 as a result of which the late medieval crisis of pluralism was settled. But recent changes in the international order, such as technological advances that have spurred globalization and the emerging norm of the Responsibility to Protect, have cast the notion of sovereignty into an unclear light. The purpose of this paper is to contribute to the current debate regarding sovereignty by exploring two schools of thought on the matter: first, three Catholic scholars from the past century—Luigi Sturzo, Jacques Maritain, and John Courtney Murray, S.J.—taken as representative of Catholic tradition; second, a number of contemporary political theorists of cosmopolitan democracy. The paper argues that there is a confluence between the Catholic thinkers and the cosmopolitan democrats regarding their understanding of state sovereignty and that, taken together, the two schools have much to contribute not only to our current understanding of sovereignty, but also to the future of global governance.

Aftershocks

2017 ◽  
Author(s):  
Seva Gunitsky
Keyword(s):  
Twentieth Century ◽  
Regime Change ◽  
International System ◽  
Political Legitimacy ◽  
Great Powers ◽  
Past Century ◽  
The Past ◽  
Sudden Rise ◽  
The World ◽  
National Borders

Over the past century, democracy spread around the world in turbulent bursts of change, sweeping across national borders in dramatic cascades of revolution and reform. This book offers a new global-oriented explanation for this wavelike spread and retreat—not only of democracy but also of its twentieth-century rivals, fascism, and communism. The book argues that waves of regime change are driven by the aftermath of cataclysmic disruptions to the international system. These hegemonic shocks, marked by the sudden rise and fall of great powers, have been essential and often-neglected drivers of domestic transformations. Though rare and fleeting, they not only repeatedly alter the global hierarchy of powerful states but also create unique and powerful opportunities for sweeping national reforms—by triggering military impositions, swiftly changing the incentives of domestic actors, or transforming the basis of political legitimacy itself. As a result, the evolution of modern regimes cannot be fully understood without examining the consequences of clashes between great powers, which repeatedly—and often unsuccessfully—sought to cajole, inspire, and intimidate other states into joining their camps.

Variable oil and argumentative conflict in the Middle East

2020 ◽  
pp. 824
Author(s):  
Malik Daham Mata’ab
Keyword(s):  
Middle East ◽  
Past Century ◽  
Large Area ◽  
The Past ◽  
The World

Oil has formed since its discovery so far one of the main causes of global conflict, has occupied this energy map a large area of conflict the world over the past century, and certainly this matter will continue for the next period in our century..

Mahmood Hasan Khan. Underdevelopment and Agrarian Structure in Pakistan. Boulder, Colorado: Westview Press. 1981. pp.xviii+ 307.

1981 ◽  
Vol 20 (4) ◽  
pp. 465-468 ◽  
Author(s):  
Douglas H. Perry
Keyword(s):  
Ownership Structure ◽  
Land Reform ◽  
Land Ownership ◽  
Past Century ◽  
The Past ◽  
Ownership Patterns ◽  
Agrarian Structure

Students of the land ownership patterns in Pakistan have always been hampered by extreme lack of data, neither the 1960 census nor the 1972 census reveal anything about the actual ownership structure of land. Khan's book goes some distance in providing numbers on land ownership (for 1971 and 1976), and also documents methods and failures of land reform efforts over the past century in Pakistan, disaggregated to show efforts in this regard in both the provinces of Sind and Punjab. The book actually provides an overwhelming amount of data - some 87 pages of charts and tables document a book of under 200 pages of text.

scholarly journals Adolescent and adult laryngotracheal stenosis: a review

2021 ◽  
Vol 37 (1) ◽  
Author(s):  
Gerhard Johan Klopper ◽  
Oladele Vincent Adeniyi ◽  
Kate Stephenson
Keyword(s):  
Intensive Care ◽  
Past Century ◽  
Main Body ◽  
Laryngotracheal Stenosis ◽  
Airway Protection ◽  
Interventional Pulmonology ◽  
The Past ◽  
Airway Emergency ◽  
The Individual ◽  
And Function

Abstract Background The larynx has multiple composite functions which include phonation, airway protection, and sensory control of respiration. Stenosis of the larynx and trachea were first recorded by O’Dwyer in 1885 and by Colles in 1886, respectively. Initially, the aetiology of laryngotracheal stenosis was predominantly infective. Currently, the leading cause is iatrogenic injury to the laryngotracheal complex secondary to prolonged ventilation in an intensive care unit. Main body Laryngotracheal stenosis is a complex and diverse disease. It poses a major challenge to the surgeon and can present as an airway emergency. Management typically demands the combined involvement of various disciplines including otorhinolaryngology, cardiothoracic surgery, anaesthesiology, interventional pulmonology, and radiology. Both the disease and its management can impact upon respiration, voice, and swallowing. The incidence of iatrogenic laryngotracheal stenosis has reflected the evolution of airway and intensive care whilst airway surgery has advanced concurrently over the past century. Correction of laryngotracheal stenosis requires expansion of the airway lumen; this is achieved by either endoscopic or open surgery. We review the relevant basic science, aetiopathogenesis, diagnosis, management, and treatment outcomes of LTS. Conclusion The choice of surgical procedure in the management of laryngotracheal stenosis is often dictated by the individual anatomy and function of the larynx and trachea, together with patient factors and available facilities. Regardless of how the surgeon chooses to approach these lesions, prevention of iatrogenic laryngotracheal damage remains of primary importance.

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