Huygens' headache

Cephalalgia ◽  
2015 ◽  
Vol 35 (13) ◽  
pp. 1215-1219
Author(s):  
Peter J Koehler
Keyword(s):  
Family History ◽  
Wave Phenomenon ◽  
Royal Society ◽  
17Th Century ◽  
Christiaan Huygens ◽  
Académie Des Sciences ◽  
Two Generations ◽  
The Impact ◽  
Dutch Mathematician ◽  
Pendulum Clock

Background Christiaan Huygens (1629–1695) was a Dutch mathematician, physicist, and astronomer. He became well-known as inventor of the pendulum clock and described light as a wave phenomenon. He became Fellow of the Royal Society (London) and member of the Académie des Sciences (Paris). From the correspondence with family members and famous scientists, we learn that he suffered from frequent headaches. Aim To study Huygens' 22-volume Oeuvres Complètes (1888–1950) to find letters in which his headaches are mentioned and translate pertinent sections into English. Conclusions Although a posthumous diagnosis of Huygens' headaches is somewhat hazardous, the recurrent episodes with incapacitating headache and family history over two generations are suggestive for migraine. It becomes clear that it impeded his writing, reading, and research. From the letters we get an impression of the impact of the headache upon his life and the treatments that were applied in the 17th century.

The Nature of Light

2017 ◽  
Author(s):  
Frank S. Levin
Keyword(s):  
Wave Phenomenon ◽  
Electromagnetic Waves ◽  
Speed Of Light ◽  
Particle Theory ◽  
Christiaan Huygens ◽  
Slit Experiment

Chapter 2 reviews answers to the question of what is light, starting with the ancient Greeks and ending in 1900 with the wave concept of Maxwell’s electrodynamics. For some ancient Greeks, light consisted of atoms emitted from surface of the object, whereas for others it was fire that either entered into or was emitted by eyes, although the latter possibility was effectively eliminated around the year 1000. Competing proposals well after then were that light is either a wave phenomenon or consists of particles, with Isaac Newton’s corpuscular (particle) theory prevailing by the end of the 1600s over the wave concept championed by Christiaan Huygens, who published the first estimate of the speed of light. In the early 1800s, Thomas Young’s two-slit experiment proved that light was a wave, a concept codified and firmly grounded through Maxwell’s theory of electromagnetic waves.

scholarly journals Relative contributions of family history and a polygenic risk score on COPD and related outcomes: COPDGene and ECLIPSE studies

2020 ◽  
Vol 7 (1) ◽  
pp. e000755
Author(s):  
Matthew Moll ◽  
Sharon M. Lutz ◽  
Auyon J. Ghosh ◽  
Phuwanat Sakornsakolpat ◽  
Craig P. Hersh ◽  
...  
Keyword(s):  
Family History ◽  
Risk Score ◽  
Characteristic Curve ◽  
Significant Proportion ◽  
Chronic Obstructive ◽  
Polygenic Risk Score ◽  
Positive Interaction ◽  
Polygenic Risk ◽  
Mediation Analyses ◽  
The Impact

IntroductionFamily history is a risk factor for chronic obstructive pulmonary disease (COPD). We previously developed a COPD risk score from genome-wide genetic markers (Polygenic Risk Score, PRS). Whether the PRS and family history provide complementary or redundant information for predicting COPD and related outcomes is unknown.MethodsWe assessed the predictive capacity of family history and PRS on COPD and COPD-related outcomes in non-Hispanic white (NHW) and African American (AA) subjects from COPDGene and ECLIPSE studies. We also performed interaction and mediation analyses.ResultsIn COPDGene, family history and PRS were significantly associated with COPD in a single model (PFamHx <0.0001; PPRS<0.0001). Similar trends were seen in ECLIPSE. The area under the receiver operator characteristic curve for a model containing family history and PRS was significantly higher than a model with PRS (p=0.00035) in NHWs and a model with family history (p<0.0001) alone in NHWs and AAs. Both family history and PRS were significantly associated with measures of quantitative emphysema and airway thickness. There was a weakly positive interaction between family history and the PRS under the additive, but not multiplicative scale in NHWs (relative excess risk due to interaction=0.48, p=0.04). Mediation analyses found that a significant proportion of the effect of family history on COPD was mediated through PRS in NHWs (16.5%, 95% CI 9.4% to 24.3%), but not AAs.ConclusionFamily history and the PRS provide complementary information for predicting COPD and related outcomes. Future studies can address the impact of obtaining both measures in clinical practice.

scholarly journals Considerations of the Scale of Radiocarbon Offsets in the East Mediterranean, and Considering a Case for the Latest (Most Recent) Likely Date for the Santorini Eruption

Radiocarbon ◽  
2012 ◽  
Vol 54 (3-4) ◽  
pp. 449-474 ◽  
Author(s):  
Sturt W Manning ◽  
Bernd Kromer
Keyword(s):  
Time Horizon ◽  
Weighted Average ◽  
17Th Century ◽  
Data Sets ◽  
East Mediterranean ◽  
Average Value ◽  
Accuracy And Precision ◽  
Wide Range ◽  
The Impact ◽  
East Mediterranean Region

The debate over the dating of the Santorini (Thera) volcanic eruption has seen sustained efforts to criticize or challenge the radiocarbon dating of this time horizon. We consider some of the relevant areas of possible movement in the14C dating—and, in particular, any plausible mechanisms to support as late (most recent) a date as possible. First, we report and analyze data investigating the scale of apparent possible14C offsets (growing season related) in the Aegean-Anatolia-east Mediterranean region (excluding the southern Levant and especially pre-modern, pre-dam Egypt, which is a distinct case), and find no evidence for more than very small possible offsets from several cases. This topic is thus not an explanation for current differences in dating in the Aegean and at best provides only a few years of latitude. Second, we consider some aspects of the accuracy and precision of14C dating with respect to the Santorini case. While the existing data appear robust, we nonetheless speculate that examination of the frequency distribution of the14C data on short-lived samples from the volcanic destruction level at Akrotiri on Santorini (Thera) may indicate that the average value of the overall data sets is not necessarily the most appropriate14C age to use for dating this time horizon. We note the recent paper of Soter (2011), which suggests that in such a volcanic context some (small) age increment may be possible from diffuse CO2emissions (the effect is hypothetical at this stage and hasnotbeen observed in the field), and that "if short-lived samples from the same stratigraphic horizon yield a wide range of14C ages, the lower values may be the least altered by old CO2." In this context, it might be argued that a substantive “low” grouping of14C ages observable within the overall14C data sets on short-lived samples from the Thera volcanic destruction level centered about 3326–3328 BP is perhaps more representative of the contemporary atmospheric14C age (without any volcanic CO2contamination). This is a subjective argument (since, in statistical terms, the existing studies using the weighted average remain valid) that looks to support as late a date as reasonable from the14C data. The impact of employing this revised14C age is discussed. In general, a late 17th century BC date range is found (to remain) to be most likelyeven ifsuch a late-dating strategy is followed—a late 17th century BC date range is thus a robust finding from the14C evidence even allowing for various possible variation factors. However, the possibility of a mid-16th century BC date (within ∼1593–1530 cal BC) is increased when compared against previous analyses if the Santorini data are considered in isolation.

Results from London Regional Clinical Genetics services over a 5-year period on germline TP53 testing in women diagnosed with breast cancer at <30 years

2021 ◽  
pp. jmedgenet-2021-107742
Author(s):  
Alice Garrett ◽  
Sabrina Talukdar ◽  
Louise Izatt ◽  
Angela F Brady ◽  
Sinead Whyte ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Family History ◽  
Pathogenic Variant ◽  
Her2 Status ◽  
Clinical Genetics ◽  
Premenopausal Breast Cancer ◽  
Genetic Test Results ◽  
Genetics Services ◽  
Clinical Genetics Services ◽  
The Impact

BackgroundThe most common cancer diagnosed in germline TP53 pathogenic variant (PV) carriers is premenopausal breast cancer. An increased rate of breast tumour HER2 positivity has been reported in this group. Screening for breast/other cancers is recommended in PV carriers.Objectives1. To assess the frequency of germline TP53 PVs reported diagnostically in women with breast cancer at <30 years of age.2. To evaluate the impact of personal/family history and HER2 status on the likelihood of germline TP53 pathogenic/likely pathogenic variant (PV/LPV) identification.MethodsGenetic test results from patients undergoing diagnostic germline TP53 tests between 2012 and 2017 in the four London Regional Clinical Genetics Services were reviewed. Clinical/pathology data and family history were extracted from genetics files for women diagnosed with breast cancer at <30 years.ResultsThe overall germline TP53 PV/LPV variant detection rate was 9/270=3.3% in all women diagnosed with breast cancer at <30 years and 2/171=1.2% in those with no second/subsequent cancer diagnosis or family history of TP53-spectrum cancers. Breast cancers were significantly more likely to be HER2-positive in TP53 PV/LPV carriers than in non-carriers (p=0.00006).ConclusionsGermline TP53 PVs/LPVs are uncommon among women diagnosed with breast cancer aged <30 years without other relevant personal or family cancer history but have an important clinical impact when identified.

Prince Rupert’s drops

1986 ◽  
Vol 41 (1) ◽  
pp. 1-26 ◽  
Keyword(s):  
Royal Society ◽  
Molten Glass ◽  
Cold Water ◽  
17Th Century ◽  
Glass Beads ◽  
The Other ◽  
Full Report ◽  
Finger Pressure

On 4 March 1660—61 ‘glass bubbles’ were first introduced to a meeting of the Royal Society. According to the minutes, ‘The King sent by Sir Paul Neile five little glass bubbles, two with liquor in them, and the other three solid, in order to have the judgement of the society concerning them’ (1). The Royal Society responded with remarkable celerity: its amanuensis produced some more drops two days later, which ‘succeeded in the same manner with those sent by the king’ (2). A very full report of the experiments performed was given to the Royal Society on 14 August 1661 by the President, Sir Robert Moray (3). As the Royal Society did not at this time have a normal publication series the report was recorded in the Register Book (4) and first published by Merret as an appendix to his translation of Neri’s Art of Glass (5). Henry Oldenburg lent Sir Robert’s account to the French traveller Monconys in 1663 who made his own translation into French of the prescription for making the drops. Monconys published this prescription in the second part of his Voyages (6). The ‘bubbles’— the solid ones, at least— were what were later to be called ‘Prince Rupert’s drops’. (Those said to contain ‘liquor’ could have been something different, but were probably the same containing vacuoles and no actual liquid.) These objects, glass beads with the form of a tear-drop tapering to a fine tail, made (though that was not generally known at the time) by dripping molten glass into cold water, exhibited a paradoxical combination of strength and fragility not without interest to the materials scientist of the present day, and which could not fail to excite the imagination of natural (and not so natural) philosphers of the 17th century. The head withstands hammering on an anvil, or, as a more modern test, squeezing in a vice, indenting its steel jaws, without fracture: yet breaking the tail with finger pressure caused the whole to explode into powder.

scholarly journals FILOSOFIJA IR XVII a. MOKSLO REVOLIUCIJA

Problemos ◽  
2006 ◽  
Vol 70 ◽  
Author(s):  
Evaldas Nekrašas
Keyword(s):  
Scientific Revolution ◽  
17Th Century ◽  
Special Science ◽  
The Impact ◽  
Intellectual Power ◽  
The Revolution

Straipsnyje nagrinėjama, kokią įtaką filosofijos raidai turėjo XVII a. mokslo revoliucija, daugiausia dėmesio skiriant jos padariniams reinterpretuojant filosofijos ir mokslo santykį. Argumentuojama, kad filosofijos, visų pirma metafizikos ir mokslo santykį transformavo aristoteliškosios mokslo plėtotės programos pakeitimas pitagoriškąja – matematizuotos eksperimentinės gamtotyros atsiradimas leido griežčiau atskirti fiziką nuo metafizikos. Specialiųjų mokslų ir metafizikos tikslų, metodų ir nagrinėjamų problemų pobūdžio supriešinimas sudarė pagrindą atsirasti pozityvistiniams filosofijos pertvarkymo į specialųjį mokslą projektams. Straipsnis baigiamas išvada, kad mokslas, jau XVII amžiuje ėmęs virsti intelektualine jėga, pranokstančia filosofiją pagal reikšmę ir įtaką, privertė filosofiją ir filosofus užimti vienokią ar kitokią poziciją savo atžvilgiu. Ši pozicija iš esmės nulemia tiek filosofavimo būdų spektrą, tiek skirtingų filosofavimo būdų santykį. Patys filosofai nebūtinai šią poziciją aiškiai reflektuoja ir fiksuoja, bet ji visada yra tam tikro filosofavimo būdo pasirinkimo pagrindas.Pagrindiniai žodžiai: Newtonas, Hume’as, metafizika, pozityvizmas. PHILOSOPHY AND THE 17TH CENTURY SCIENTIFIC REVOLUTIONEvaldas Nekrašas Summary The paper deals with the issue of the impact of the 17th century scientific revolution upon the development of philosophy. The main focus is relation between science and philosophy and effects of the revolution on the interpretation of that relation. The author argues that the relation between metaphysics and science has been transformed due to the replacement of the Aristotelian programme of the development of science by the Pythagorean one. The contraposition of aims, methods and problems characteristic of special science to those typical of metaphysics created preconditions for bringing forward the positivist schemes of the transformation of philosophy into one or another special science. The paper ends with the conclusion that science which already in the 17th century became an intellectual power excelling philosophy in significance and influence forced philosophy and philosophers to take a specific stance on it. This stance determines the spectrum of different ways of doing philosophy and their relation to each other. Some philosophers do not reflect the stance on science taken by them. But this stance always affects the choice of ways of doing philosophy.Keywords: Newton, Hume, metaphysics, positivism.

scholarly journals Desert Bighorn Sheep: Changes in Genetic Variation Over Time and the Impact of Merging Populations

2014 ◽  
Vol 5 (1) ◽  
pp. 3-13 ◽  
Author(s):  
Philip W. Hedrick ◽  
John D. Wehausen
Keyword(s):  
Genetic Variation ◽  
New Mexico ◽  
Monitoring And Evaluation ◽  
Bighorn Sheep ◽  
Ovis Canadensis ◽  
Mexican Population ◽  
Desert Bighorn Sheep ◽  
Two Generations ◽  
The Impact ◽  
Over Time

Abstract Founder effects, genetic bottlenecks, and genetic drift in general can lead to low levels of genetic diversity, which can influence the persistence of populations. We examine genetic variation in two populations of desert bighorn sheep Ovis canadensis from New Mexico and Mexico to measure change over time and evaluate the impact of introducing individuals from one population into the other. Over about three generations, the amount of genetic variation in the New Mexico population increased. In contrast, over about two generations the amount of genetic variation in the Mexican population decreased by a great extent compared with an estimate from another Mexican population from which it is primarily descended. The potential reasons for these changes are discussed. In addition, although both populations have low genetic variation, introduction of Mexican rams into the New Mexico population might increase the amount of genetic variation in the New Mexico population. Overall, it appears that management to increase genetic variation might require substantial detailed monitoring and evaluation of ancestry from the different sources and fitness components.

scholarly journals The impact and importance of new technologies in business development in context of economic diversity

2017 ◽  
Vol 11 (1) ◽  
pp. 698-710 ◽  
Author(s):  
Oana-Georgiana Ciobanu ◽  
Daniela Mihaela Neamţu
Keyword(s):  
Generation X ◽  
New Technologies ◽  
Technological Development ◽  
Qualitative Comparative Analysis ◽  
Business Environment ◽  
Management Style ◽  
Group Method ◽  
Continuous Innovation ◽  
Two Generations ◽  
The Impact

Abstract In a globalized world, led and connected by and through technology, gadgets and perpetual and intense technological development, the business environment and the trajectory travelled by entrepreneurs in the process of creation and development of a business, becomes more and more challenging and complex. Continuous innovation has become mandatory and „adaptability” became the keyword for the success of any entrepreneurial actions. In this socio-economic context, an organization must find, through entrepreneurs or managers, the courage to face the uncertainty and be always prepared to adopt radical solutions, so that, can provide sustainability of the business through competitiveness. The purpose of this research started from the need for adaptability and flexibility of the Romanian entrepreneurial environment to the trends in the digital era, in order to maintain the level of competitiveness and to develop sustainably. The objective of this scientific approach is to conduct a qualitative comparative analysis relating to the importance and the impact of new technologies in the development and sustainability of a business. The comparison will be made through the eyes of two main categories of actors in the creation and development of a business namely entrepreneurs and managers from two consecutive generations - generation X (born between 1965 and 1980) and generation Y (born between 1980 and 1995). The methodology used in this study is qualitative research through focus group method, and it aims to be highlighted the changes occurred in leadership and management style of a business/organization, by observing and comparing the two generations' attitudes towards change, towards new, towards the digital component, and the intent of the use of new technologies, and more than that, their impact on the management style.

scholarly journals Predictors of Progressive Course of Multifocal Atherosclerosis in Patients With Myocardial Infarction

Kardiologiia ◽  
2019 ◽  
Vol 59 (5) ◽  
pp. 36-44 ◽  
Author(s):  
D. Yu. Sedykh ◽  
A. N. Kazantsev ◽  
R. S. Tarasov ◽  
V. V. Kashtalap ◽  
A. N. Volkov ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Family History ◽  
Syntax Score ◽  
Coronary Syndrome ◽  
History Of ◽  
One Year ◽  
Ica Stenosis ◽  
The Impact ◽  
Progression Of Atherosclerosis ◽  
Progressive Course

Purpose. Determination of clinical and instrumental predictors of progressive course of multifocal atherosclerosis (MFA) in patients one year after myocardial infarction (MI), initially having hemodynamically insignificant stenoses of carotid arteries.Materials and methods. From database of patients with acute coronary syndrome treated in the Kemerovo Regional Clinical Cardiac Dispensary in 2009–2010 we selected for this study 141 patients with verified diagnosis of MI and hemodynamically insignificant lesions in the internal carotid artery (ICA) (stenosis up ≤ 55 %). All patients had coronary atherosclerosis verified on coronary angiography at admission because of MI. A multivariate analysis of possible predictors of the progressive course of multifocal atherosclerosis was made based on assessment of the development of cardiovascular complications (CVC) (death, MI, stroke and transient cerebral circulatory attacks [TIA]), as well as revascularizations and negative dynamics of parameters of color duplex scanning (CDS) of ICA during one year after MI. Results. One year after MI the overall incidence of CVC was 16.3 % (n=23). Structure of registered events was as follows: death from MI 7.1 % (n=10), deaths from stroke 2.1 % (n=3) and other causes 2.1 % (n=3), non-fatal MI 5.0 % (n=7), non-fatal stroke / TIA 2.1 % (n=3), carotid revascularization 2.8 % (n=4), coronary revascularization 14.9 % (n=21). CDC of ICAs was repeated in 125 patients. There were 17 (13.6 %) cases of progression of carotid atherosclerosis in the form of de novo bilateral stenoses in 14 (11.2 %) patients, stenoses in the left and right ICA 1 patient and 2 patients, respectively. The following predictors of progression of atherosclerosis of cerebral arteries were identified: family history of cardiovascular diseases (CVD),ICA stenosis ≥45 %, baseline circular atherosclerotic plaque (ASP). Predictors of high risk of stroke were family history of CVD, history of stroke,ICA stenosis ≥45 %, heterogeneous hypoechoic ASP. As predictors of lethal outcome, we identified history of MI, high functional class of angina preceding the index MI, severe coronary vascular bed involvement (SYNTAX score >23), presence of any bilateral atherosclerotic lesion in ICAs, and heterogeneous hypoechoic ASP. Assessment of the contribution of adherence to therapy in the prognosis 1 year after hospital discharge was fulfilled in 125 alive patients. It allowed to conclude that patients with progression of atherosclerosis and nonfatal CVC were characterized by insufficient adherence to standard therapy.Conclusion. Predictors of the progressive course of multifocal atherosclerosis during one year after MI were identified in this study. It is necessary to strengthen therapeutic and preventive measures aimed at minimization of the impact of these factors in this category of patients.   

Abstract 368: Family History of Premature Cardiac Events and Sub Clinical Atherosclerosis in Children and Young Adults: A Systematic Review

2013 ◽  
Vol 33 (suppl_1) ◽  
Author(s):  
Pragya Sinha ◽  
Jamal S Rana ◽  
Ebenezer T Oni ◽  
Ehimen C Aneni ◽  
Roger S Blumenthal ◽  
...  
Keyword(s):  
Cardiovascular Disease ◽  
Young Adults ◽  
Family History ◽  
Endothelial Dysfunction ◽  
Subclinical Atherosclerosis ◽  
Vascular Inflammation ◽  
Positive Family History ◽  
Cardiac Risk Factor ◽  
Children And Young Adults ◽  
The Impact

BACKGROUND The association between a positive family history (PFH) of premature cardiovascular disease (PCVD) and atherosclerosis has been explored in numerous studies. In adults, various studies have confirmed a significant positive correlation between a PFH and PCVD. Scant literature however, focuses on young individuals. Nevertheless, it is important to understand the impact that a PFH has in young people because the foundations of atherosclerosis and adverse cardiac behaviors develop in youth. In this paper, we aimed to systematically review the evidence linking a PFH of PCVD to indirect markers of subclinical atherosclerosis. METHODS The search was conducted on Medline, Web of Science and Embase. ‘Family history’, ‘children/young adults’ and ‘subclinical atherosclerosis’ were the three main concepts used. Increase in mean carotid IMT (cIMT), endothelial dysfunction and vascular inflammation were used as indirect measures of subclinical atherosclerosis. RESULTS 1191 articles were identified in the initial search. 24 papers with 5400 participants were included in the final review. There were five cohort studies and nineteen case control studies from twelve countries. Mean cIMT was found to be significantly increased in those with a PFH by eleven of the fourteen papers reviewed. Endothelial dysfunction, measured by flow mediated dilatation (FMD), was found to be significantly increased in five of the seven included studies. The evidence on vascular inflammation was somewhat inconsistent with only ten of the nineteen studies demonstrating significance. The results tend to suggest that an elevated mean cIMT, as well as a greater degree of endothelial dysfunction are seen in children and young adults with a PFH of PCVD. Moreover, these differences exist in asymptomatic children as young as 8-9 years (4 studies) in the absence of any other cardiac risk factor. DISCUSSION Individuals with a PFH of PCVD have evidence of subclinical atherosclerosis in their youth demonstrating an accelerated tendency to acquire cardiovascular disease. Some of this risk may be attributable to behavioral risk clustering in families. However, a significant proportion of this elevated risk is related solely to a positive family history and needs attention.

Sign in / Sign up

Export Citation Format

Share Document