Creation, Contingency, and Early Modern Science: The Impact of Voluntarist Theology on Seventeenth-Century Natural Philosophy

Could God have made it true that 2 + 2 = 5? Was he bound to make the best of all possible worlds? Is he able at this moment to alter the course of nature, either in whole or in part? Questions like these are often associated with medieval theology, not with early modern science. But science is done by people, and people have not always practiced the rigorous separation of science and theology that has come to characterize the modern world. Although many 17th century scientists sought validity for their work apart from revelation, divorcing science from religion was something they never intended. Indeed most natural philosophers of the scientific revolution assumed without question that the world and the human mind had been created by God. This was no small admission, for it meant that both the manner in which and the degree to which the world could be understood depended upon how God had acted in creating it and how he continued to act in sustaining it. Fifty years ago the late British philosopher M.B. Foster identified two different theologies of creation which differ profoundly in their implications for natural science. Rationalist theology, which assigns to God the activity of pure reason, involves both a rationalist X philosophy of nature and a rationalist theory of knowledge of nature. Voluntarist theology, which attributes to God an activity of will not wholly determined by reason, implies that the products of his creative activity are contingent and can be known only empirically. By a careful analysis of four natural philosophies of the early modern period--those of Galileo, Descartes, Boyle, and Newton--! intend to show that there was indeed a connection between theological voluntarism and empirical science in the 17th century

Markers of Myocardial Damage Predict Mortality in Patients With Aortic Stenosis

Background: Cardiovascular magnetic resonance (CMR) is increasingly used for risk stratification in aortic stenosis (AS). However, the relative prognostic power of CMR markers and their respective thresholds remains undefined. Objectives: Using machine learning, the study aimed to identify prognostically important CMR markers in AS and their thresholds of mortality. Methods: Patients with severe AS undergoing AVR (n = 440, derivation; n = 359, validation cohort) were prospectively enrolled across 13 international sites (median 3.8 years’ follow-up). CMR was performed shortly before surgical or transcatheter AVR. A random survival forest model was built using 29 variables (13 CMR) with post-AVR death as the outcome. Results: There were 52 deaths in the derivation cohort and 51 deaths in the validation cohort. The 4 most predictive CMR markers were extracellular volume fraction, late gadolinium enhancement, indexed left ventricular end-diastolic volume (LVEDVi), and right ventricular ejection fraction. Across the whole cohort and in asymptomatic patients, risk-adjusted predicted mortality increased strongly once extracellular volume fraction exceeded 27%, while late gadolinium enhancement >2% showed persistent high risk. Increased mortality was also observed with both large (LVEDVi >80 mL/m2) and small (LVEDVi ≤55 mL/m2) ventricles, and with high (>80%) and low (≤50%) right ventricular ejection fraction. The predictability was improved when these 4 markers were added to clinical factors (3-year C-index: 0.778 vs 0.739). The prognostic thresholds and risk stratification by CMR variables were reproduced in the validation cohort. Conclusions: Machine learning identified myocardial fibrosis and biventricular remodeling markers as the top predictors of survival in AS and highlighted their nonlinear association with mortality. These markers may have potential in optimizing the decision of AVR

Extracellular Myocardial Volume in Patients With Aortic Stenosis

BACKGROUND: Myocardial fibrosis is a key mechanism of left ventricular decompensation in aortic stenosis and can be quantified using cardiovascular magnetic resonance (CMR) measures such as extracellular volume fraction (ECV%). Outcomes following aortic valve intervention may be linked to the presence and extent of myocardial fibrosis. OBJECTIVES: This study sought to determine associations between ECV% and markers of left ventricular decompensation and post-intervention clinical outcomes. METHODS: Patients with severe aortic stenosis underwent CMR, including ECV% quantification using modified Look-Locker inversion recovery-based T1 mapping and late gadolinium enhancement before aortic valve intervention. A central core laboratory quantified CMR parameters. RESULTS: Four-hundred forty patients (age 70 ± 10 years, 59% male) from 10 international centers underwent CMR a median of 15 days (IQR: 4 to 58 days) before aortic valve intervention. ECV% did not vary by scanner manufacturer, magnetic field strength, or T1 mapping sequence (all p > 0.20). ECV% correlated with markers of left ventricular decompensation including left ventricular mass, left atrial volume, New York Heart Association functional class III/IV, late gadolinium enhancement, and lower left ventricular ejection fraction (p < 0.05 for all), the latter 2 associations being independent of all other clinical variables (p = 0.035 and p < 0.001). After a median of 3.8 years (IQR: 2.8 to 4.6 years) of follow-up, 52 patients had died, 14 from adjudicated cardiovascular causes. A progressive increase in all-cause mortality was seen across tertiles of ECV% (17.3, 31.6, and 52.7 deaths per 1,000 patient-years; log-rank test; p = 0.009). Not only was ECV% associated with cardiovascular mortality (p = 0.003), but it was also independently associated with all-cause mortality following adjustment for age, sex, ejection fraction, and late gadolinium enhancement (hazard ratio per percent increase in ECV%: 1.10; 95% confidence interval [1.02 to 1.19]; p = 0.013). CONCLUSIONS: In patients with severe aortic stenosis scheduled for aortic valve intervention, an increased ECV% is a measure of left ventricular decompensation and a powerful independent predictor of mortality

Sex differences in left ventricular remodelling, myocardial fibrosis and mortality after aortic valve replacement

Objectives: To investigate sex differences in left ventricular remodelling and outcome in patients undergoing surgical or transcatheter aortic valve replacement (SAVR/TAVR). Methods: In this multicentre, observational, outcome study with imaging core-lab analysis, patients with severe aortic stenosis (AS) listed for intervention at one of six UK centres were prospectively recruited and underwent cardiovascular magnetic resonance imaging. The primary endpoint was all-cause mortality and secondary endpoint was cardiovascular mortality. Results: 674 patients (425 men, 249 women, age 75±14 years) were included: 399 SAVR, 275 TAVR. Women were older, had higher surgical risk scores and underwent TAVR more frequently (53% vs 33.6%, p<0.001). More men had bicuspid aortic valves (BAVs) (26.7% vs 14.9%, p<0.001) and demonstrated more advanced remodelling than women. During a median follow-up of 3.6 years, 145 (21.5%) patients died, with no significant sex difference in all-cause mortality (23.3% vs 20.5%, p=0.114), but higher cardiovascular mortality in women (13.7% vs 8.5%, p=0.012). There were no significant sex-related differences in outcome in the SAVR or TAVR subgroups, or after excluding those with BAV. Factors independently associated with all-cause mortality were age, left ventricular ejection fraction (LVEF), BAV (better) and myocardial fibrosis detected with late gadolinium enhancement (LGE) in men, and age, LVEF and LGE in women. Age and LGE were independently associated with cardiovascular mortality in both sexes. Conclusions: Men demonstrate more advanced remodelling in response to a similar severity of AS. The higher cardiovascular mortality observed in women following AVR is accounted for by women having less BAV and higher risk scores resulting in more TAVR. LGE is associated with a worse prognosis in both sexes

Middle dimensional non-squeezing, infinite dimensional non-squeezing and generating functions

Wir befassen uns mit zwei möglichen Verallgemeinerungen des Non-Squeezing Theorems von Gromov. Wir beweisen zunächst ein lokales, mitteldimensionales, non-squeezing Ergebnis für analytische symplektische Einbettungen von Gebieten in einen euklidischen Raum mit ungerader Dimension. Dieses Resultat wird durch Verwendung einer Arbeit von Álvarez Paiva und Balacheff gezeigt. Der Satz, den wir erhalten, ist teilweise auf den Fall eines unendlich dimensionalen Phasenraums erweiterbar. Unser zweites Ziel ist es, ein Analogon des Non-Squeezing Theorems von Gromov in einem unendlich dimensionalen Phasenraum zu beweisen. Indem wir den Beweisideen von Hofer und Zehnder für endlich dimensionales Non-Squeezing folgen, erhalten wir ein bereits von Kuksin gezeigtes Resultat für unendlich dimensionales Non-Squeezing für symplektische Diffeomorphismen, die nicht-lineare kompakte Störungen einer symplektischen linearen Abbildung sind.We deal with two possible generalisations of Gromov's non squeezing theorem. We first prove a local middle-dimensional non-squeezing result for analytic symplectic embeddings of domains in an even dimensional Euclidean space. This claim will be deduced by taking advantage of a work by Álvarez Paiva and Balacheff. The theorem we obtain is partially extendable to the setting of an infinite dimensional phase space. Our second goal is to prove an analogous of the Gromov's non squeezing theorem in an infinte dimensional phase space setting. By following the lines of the proof by Hofer and Zehnder of finite dimensional non-squeezing, we recover an infinite-dimensional non-squeezing result by Kuksin for symplectic diffeomorphisms which are non-linear compact perturbations of a symplectic linear map

Spontaneous hot carrier photon emission rates in silicon: improved modeling and application to metal oxide semiconductor devices

The recent publication of controversial experimental evidence on the origin of hot-carrier currents in 4-10 nm tunnel metal oxide semiconductor capacitors renewed the interest in improving hot-carrier luminescence models for silicon devices. This work presents several such improvements, aimed at making possible a physically based analysis of the hot-carrier luminescence effects taking place during tunneling experiments in relatively thick SiO2 layers. To this purpose, silicon band structure and scattering rate calculations have been extended well above 10 eV by considering eight conduction bands, instead of the usual four, so as to allow for a detailed description of the high-energy carriers injected from silicon into silicon dioxide during tunneling experiments. The absolute contributions of the direct and phonon-assisted, interband and intraband transitions of electrons and holes to the total photon emission rate are analyzed, so the results can be directly compared with the experimental data. To the best of our knowledge, it is for the first time that results for valence-to-valence band transitions of holes are presented and compared with those of conduction-to-conduction band transitions of electrons. Results can be directly compared with experimental data. Template results obtained with a variety of carrier distributions (Maxwellian, Gaussian, and Dirac's delta-like) are shown and implications for device analysis are discussed

Optical characterization of radiative deep centres in 6H-SiC junction field effect transistors

Electroluminescence studies were carried out as a function of bias and temperature to understand the nature of deep centres in 6H–SiC n-channel junction field-effect transistors (FETS) for high-power applications. Vanadium impurities in different configurations were suggested to be responsible for the levels found. The contributions of hot and cold carriers were distinguished by biasing the devices both in the transistor-like and in the diode-like configurations. This allowed us to spatially localize the deep centres inside the device structure. In the transistor-like configuration, two broad emission bands (1.1–1.7 eV and 2.5–3 eV), superimposed to the contribution arising from hot carrier intraband transitions, were detected. The A band at 1.17 eV (observed only in the transistor-like configuration) was attributed to a radiative transition between an excited level and its ground state of a vanadium centre located in the n-type conductive channel. The B (1.32 eV) and C (1.62 eV) bands originated from the space–charge region of the p–n junctions in both the configurations and, contrary to the A band, they were characterized by a thermal capture barrier (180 meV) which inhibits the luminescence in the diode-like configuration at temperatures below 200 K