The following article complements my previous one concerning the COVID-19 pandemic and chloroquine. I suggest you read it first, as it will give you an idea of what the scientific literature says about the action of chloroquine on COVID-19 as of April 7th, 2020. However, this article did neither address the question of ethics, nor fully address whether the situation could justify not to follow the usual methodology.
Indeed, this objection is regularly raised: “even though it has not been established that hydroxychloroquine can actually be used as a treatment for COVID-19, ultimately the dosage is well known and there is probably not a great risk in administering it to patients.” Moreover, there is a view which seems to have some popularity, stating that, considering the circumstances, clinicians should not take too much care to comply with methodology, as the emergency dictates to be less rigorous with procedures. These two issues are related. To address them, one must both look at the collective experience and assess what is not known.
On March 25th, 2020, a study presenting the case of 416 patients with COVID-19 was published1Shaobo Shi, Mu Qin, Bo Shen, Yuli Cain, Tao Liu, Fan Yang, Wei Gong, Xu Liu, Jinjun Liang, Qinyan Zhao, He Huang, Bo Yang, and Congxin Huang, 2020. ‘Association of cardiac injury with mortality in hospitalized patients with COVID-19 in Wuhan, China’, JAMA Cardiology. Doi: 10.1001/jamacardio.2020.0950. Among these patients, 19.7 % had cardiac problems. It is not surprising that patients in respiratory distress, one of the complications of COVID-19, have heart problems. However, the study reports a suspicion that these cardiac problems are not a consequence of this respiratory distress, but directly due to the action of the virus. Another compilation of COVID-19 case analysis also supports this suspicion2Elissa Driggin, Mahesh V. Madhavan, Behnood Bikdeli, Taylor Chuich, Justin Laracy, Giuseppe Bondi-Zoccai, Tyler S. Brown, Caroline Der Nigoghossian, David A. Zidar, Jennifer Haythe, Daniel Brodie, Joshua A. Beckman, Ajay J. Kirtane, Gregg W. Stone, Harlan M. Krumholz and Sahil A. Parikh, 2020. ‘Cardiovascular considerations for patients, health care workers, and health systems during the coronavirus disease 2019 (COVID-19) pandemic’, Journal of th American College of Cardiology. Doi: 10.1016/j.jacc.2020.03.031.
Shaobo Shi, Mu Qin, Bo Shen, Yuli Cain, Tao Liu, Fan Yang, Wei Gong, Xu Liu, Jinjun Liang, Qinyan Zhao, He Huang, Bo Yang, and Congxin Huang, 2020. ‘Association of cardiac injury with mortality in hospitalized patients with COVID-19 in Wuhan, China’, JAMA Cardiology. Doi: 10.1001/jamacardio.2020.0950
Elissa Driggin, Mahesh V. Madhavan, Behnood Bikdeli, Taylor Chuich, Justin Laracy, Giuseppe Bondi-Zoccai, Tyler S. Brown, Caroline Der Nigoghossian, David A. Zidar, Jennifer Haythe, Daniel Brodie, Joshua A. Beckman, Ajay J. Kirtane, Gregg W. Stone, Harlan M. Krumholz and Sahil A. Parikh, 2020. ‘Cardiovascular considerations for patients, health care workers, and health systems during the coronavirus disease 2019 (COVID-19) pandemic’, Journal of th American College of Cardiology. Doi: 10.1016/j.jacc.2020.03.031
This article is written under rather peculiar circumstances, in fact quite dramatic ones to say the least: after a first case declared on November 17th, 20191Josephine Ma, March 13th, 2020. ‘Coronavirus: China’s first confirmed Covid-19 case traced back to November 17’, South China Morning Post. Available on-line., a COVID-19 pandemic2World Health Organization (WHO), March 11th, 2020. WHO Director-General’s opening remarks at the media briefing on COVID-19, WHO. Available on-line. has spread throughout the world. Among several consequences, this pandemic caused the confinement of the French population from March 17th, 2020 at noon. I wrote the following article in France during this confinement. Actually, the seriousness of the pandemic led a group of scientific mediators do launch a coordinate prevention message on March 14th, 2020 at 6 p.m. I associated myself to this message.
Prior to confinement, on February 25th, 2020, the IHU Méditerranée-infection released a video stating that a molecule derived from quinine, being chloroquine, is an effective treatment against COVID-19:
This was the starting point for a major media coverage of chloroquine and another derivative from quinine, being hydroxychloroquine. Since this media coverage is extremely problematic, I would like to try to give you some clearer insights. The first goal of this article will be to give you some reliable sources, as quite a lot of uninteresting opinions were given, and too few facts. Yet the facts are there. This article will therefore not contain any opinion.
In this blog and elsewhere, you have probably already seen the expression “Copernican revolution”. This expression highlights the fact that Nicolaus Copernicus (1473 – 1543) provoked a major change in perspectives by showing that it is more relevant to consider this is the Earth that is rotating around the Sun rather than the opposite. To this first upheaval echoes Galileo Galilei’s (1564 – 1642) works. The latter, on the basis of Copernicus’ work, among others, has definitively shown that Claudius Ptolemy’s (around 90 AD – about 168) system, published in the Almagest1Κλαύδιος Πτολεμαῖος, around 150 AD. Μαθηματική σύνταξις. An English translation: Gerald J. Toomer, 1998. Ptolemy’s Almagest, second edition, Princeton University Press, New York, United States of America. Available on-line. and according to which, in agreement with Aristotelian physics, the Earth was motionless in the centre of the World, was wrong.
I have alreadypresented this, with a viewfrom here. As I have indicated before, they were both preceded by Nicole Oresme’s (about 1320 or 1322 – 1382) work. Galileo also used Johannes Kepler’s (1571 – 1630) work, among others. Therefore, I have intentionally used the expression “Copernican revolution,” as well as “epistemic revolution.” But still remains the question I would like to tackle in this article: though this expression is commonly used, is it really relevant to talk about revolution? My purpose is also to lead you, my dear reader, to make some critical analysis of what I am publishing here.
Κλαύδιος Πτολεμαῖος, around 150 AD. Μαθηματική σύνταξις. An English translation: Gerald J. Toomer, 1998. Ptolemy’s Almagest, second edition, Princeton University Press, New York, United States of America. Available on-line.
The law of parsimony – sometimes called Ockham’s razor after the English Franciscan monk William of Ockham (circa 1285 – 1347), a pioneer in logic – is a principle common to philosophy and science. In fact, it has been stated before, the oldest occurrence that I have found is due to Aristotle1Ἀριστοτέλης, Φυσικὴ ἀκρόασις. Available on-line. An English translation by Robin Waterfield: David Bostock (editor), 1999. Physics, Oxford University Press. Available on-line. (384 – 322 BC), who attributes it to Empedocles (circa 490 – about 435 BC). However, Proclus (412 AD – 485) traces it back to Pythagoras (about 580 – about 495 BC)2The only version I know of the work in question is this German edition, which appears to be considered the reference: Manitius, C. (éditor et translator), 1909. Procli Diadochi hypotyposis astronomicarum positionum (Bibliotheca scriptorum Graecorum et Romanorum Teubneriana), Teubner, Leipzig. Reprinted in 1974: Teubner, Stuttgart..
No, I have not yet specified what states this law. This is a barely honest process that aims to create an almost unbearable suspense to make you captive of my prose, so that you will read this whole article. However, do not worry: the explanation comes in a few lines!
The only version I know of the work in question is this German edition, which appears to be considered the reference: Manitius, C. (éditor et translator), 1909. Procli Diadochi hypotyposis astronomicarum positionum (Bibliotheca scriptorum Graecorum et Romanorum Teubneriana), Teubner, Leipzig. Reprinted in 1974: Teubner, Stuttgart.
Among his notable works, he is a pioneer in black holes realistic representations. As early as 19791Jean-Pierre Luminet, 1979. Image of a Spherical Black Hole with Thin Accretion Disk, Astronomy and Astrophysics, n° 75, pp. 228 – 235. Available on line., he proposed a more realistic and accurate one than the one presented in Interstellar2Christopher Nolan, 2014. Interstellar, Syncopy Films and Lynda Obst Productions.. He also worked on the form – actually, its topology – of the Universe, which led him to introduce the concept of Wraparound Universe3Jean-Pierre Luminet, 2008. The Wraparound Universe, AK Peters Ltd..
Of course, if this first form of physical relativity is qualified “Galilean,” it is because Galileo had something to do in its formulation. The introduction of this principle is one of the main elements of the epistemological revolution to which I referred earlier. This article is therefore a continuation of the series on the history of science that I started. It will also be the occasion, once again, to introduce some concepts that will be useful for future popularisation articles to come.
I have already mentioned it: it is about time that I present the topics that I am interested in my work. As I have indicated on this site home page and as can be deduced from my resume, my areas of expertise are applied mathematics and theoretical computer science. My scope is physical oceanography. Specifically, I am reproducing ocean dynamics on computers.
However, though being a still evolving discipline, the study of ocean dynamics has a long history. The oldest references I have found were written during the antique times. The main topic on ocean dynamics they address is tide. I intend to present this story here. Much of the information you will find in the following comes from Bernard Simon’s La Marée océanique côtière1B. Simon, 2007. La Marée océanique côtière, collection “Synthèses”, Institut océanographique éditeur.. The following is an extract from the introduction of my Ph.D. thesis2Y. Le Bars, 2010. Modélisation de la dynamique océanique barotrope dans l’estuaire et le plateau amazoniens, Ph.D. thesis, Université de Toulouse III – Paul Sabatier.. This thesis focused on the development of an ocean model and its application to the estuary of the Amazon, so I do not claim to have achieved a definitive historical study: the following is a summary, albeit detailed, but with all the limitations of this exercise.
Is it because it concerns the origins of things? Anyway, the Big Bang is a scientific subject which everyone seems to have heard of. However, it appears that general ideas about it are not really clear.
As it will be question of the Big Bang in the subjects I will address soon in this website, here is an opportunity to inaugurate scientific popularisation articles in my blog: I propose to present the basics of the Big Bang, using simple experiments that everyone can do at home.