Neural networks represent a powerful data processing technique that has reached maturity and broad application. When clearly understood and appropriately used, they are a mandatory component in the ...toolbox of any engineer who wants make the best use of the available data, in order to build models, make predictions, mine data, recognize shapes or signals, etc. Ranging from theoretical foundations to real-life applications, this book is intended to provide engineers and researchers with clear methodologies for taking advantage of neural networks in industrial, financial or banking applications, many instances of which are presented in the book. For the benefit of readers wishing to gain deeper knowledge of the topics, the book features appendices that provide theoretical details for greater insight, and algorithmic details for efficient programming and implementation. The chapters have been written by experts and edited to present a coherent and comprehensive, yet not redundant, practically oriented introduction.
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FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The history of atmospheric O₂ partial pressures (Po₂) is inextricably linked to the coevolution of life and Earth's biogeochemical cycles. Reconstructions of past Po₂ rely on models and proxies but ...often markedly disagree. We present a record of Po₂ reconstructed using O₂/N₂ ratios from ancient air trapped in ice. This record indicates that Po₂ declined by 7 per mil (0.7%) over the past 800,000 years, requiring that O₂ sinks were ~2% larger than sources. This decline is consistent with changes in burial and weathering fluxes of organic carbon and pyrite driven by either Neogene cooling or increasing Pleistocene erosion rates. The 800,000-year record of steady average carbon dioxide partial pressures (Pco₂) but declining Po₂ provides distinctive evidence that a silicate weathering feedback stabilizes Pco₂ on million-year time scales.
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BFBNIB, NMLJ, NUK, ODKLJ, PNG, SAZU, UL, UM, UPUK
Aims/hypothesis
We examined race differences in the association between age at menarche and type 2 diabetes before and after adjustment for adiposity.
Methods
We analysed baseline and 9-year ...follow-up data from 8,491 women (
n
= 2,505 African-American, mean age 53.3 years;
n
= 5,986 white, mean age 54.0 years) in the Atherosclerosis Risk in Communities (ARIC) study. Stratifying by race, we used logistic regression to estimate the OR for prevalent diabetes at baseline, and Cox proportional hazard models to estimate the HR for incident diabetes over follow-up according to age at menarche category (8–11, 12, 13, 14 and 15–18 years).
Results
Adjusting for age and centre, we found that early age at menarche (8–11 vs 13 years) was associated with diabetes for white, but not African-American women in both the prevalent (white OR 1.72, 95% CI 1.32, 2.25; African-American OR 1.13, 95% CI 0.84, 1.51; interaction
p
= 0.043) and incident models (white HR 1.43, 95% CI 1.08, 1.89; African-American HR 1.20, 95% CI 0.87, 1.67; interaction
p
= 0.527). Adjustment for adiposity and lifestyle confounders attenuated associations for prevalent (white OR 1.41, 95% CI 1.05, 1.89; African-American OR 0.94, 95% CI 0.68, 1.30; interaction
p
= 0.093) and incident diabetes (white HR 1.22, 95% CI 0.92, 1.63; African-American HR 1.11, 95% CI 0.80, 1.56; interaction
p
= 0.554).
Conclusions/interpretation
Early menarche was associated with type 2 diabetes in white women, and adulthood adiposity attenuated the relationship. We did not find a similar association in African-American women. Our findings suggest that there may be race/ethnic differences in the influence of developmental factors in the aetiology of type 2 diabetes, which merit further investigation.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
A high-resolution deuterium profile is now available along the entire European Project for Ice Coring in Antarctica Dome C ice core, extending this climate record back to marine isotope stage 20.2, ...∼800,000 years ago. Experiments performed with an atmospheric general circulation model including water isotopes support its temperature interpretation. We assessed the general correspondence between Dansgaard-Oeschger events and their smoothed Antarctic counterparts for this Dome C record, which reveals the presence of such features with similar amplitudes during previous glacial periods. We suggest that the interplay between obliquity and precession accounts for the variable intensity of interglacial periods in ice core records.
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In this paper, we introduce a novel entropy measure, termed epoch-based entropy. This measure quantifies disorder of EEG signals both at the time level and spatial level, using local density ...estimation by a Hidden Markov Model on inter-channel stationary epochs. The investigation is led on a multi-centric EEG database recorded from patients at an early stage of Alzheimer's disease (AD) and age-matched healthy subjects. We investigate the classification performances of this method, its robustness to noise, and its sensitivity to sampling frequency and to variations of hyperparameters. The measure is compared to two alternative complexity measures, Shannon's entropy and correlation dimension. The classification accuracies for the discrimination of AD patients from healthy subjects were estimated using a linear classifier designed on a development dataset, and subsequently tested on an independent test set. Epoch-based entropy reached a classification accuracy of 83% on the test dataset (specificity = 83.3%, sensitivity = 82.3%), outperforming the two other complexity measures. Furthermore, it was shown to be more stable to hyperparameter variations, and less sensitive to noise and sampling frequency disturbances than the other two complexity measures.
The deuterium excess of polar ice cores documents past changes in evaporation conditions and moisture origin. New data obtained from the European Project for Ice Coring in Antarctica Dome C East ...Antarctic ice core provide new insights on the sequence of events involved in Termination II, the the transition between the penultimate glacial and interglacial periods. This termination is marked by a north—south seesaw behavior, with first a slow methane concentration rise associated with a strong Antarctic temperature warming and a slow deuterium excess rise. This first step is followed by an abrupt north Atlantic warming, an abrupt resumption of the East Asian summer monsoon, a sharp methane rise, and a CO₂ overshoot, which coincide within dating uncertainties with the end of Antarctic optimum. Here, we show that this second phase is marked by a very sharp Dome C centennial deuterium excess rise, revealing abrupt reorganization of atmospheric circulation in the southern Indian Ocean sector.
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An important share of paleoclimatic information is buried within the lowermost layers of deep ice cores. Because improving our records further back in time is one of the main challenges in the near ...future, it is essential to judge how deep these records remain unaltered, since the proximity of the bedrock is likely to interfere both with the recorded temporal sequence and the ice properties. In this paper, we present a multiparametric study (δD-δ18Oice, δ18Oatm, total air content, CO2, CH4, N2O, dust, high-resolution chemistry, ice texture) of the bottom 60 m of the EPICA (European Project for Ice Coring in Antarctica) Dome C ice core from central Antarctica. These bottom layers were subdivided into two distinct facies: the lower 12 m showing visible solid inclusions (basal dispersed ice facies) and the upper 48 m, which we will refer to as the "basal clean ice facies". Some of the data are consistent with a pristine paleoclimatic signal, others show clear anomalies. It is demonstrated that neither large-scale bottom refreezing of subglacial water, nor mixing (be it internal or with a local basal end term from a previous/initial ice sheet configuration) can explain the observed bottom-ice properties. We focus on the high-resolution chemical profiles and on the available remote sensing data on the subglacial topography of the site to propose a mechanism by which relative stretching of the bottom-ice sheet layers is made possible, due to the progressively confining effect of subglacial valley sides. This stress field change, combined with bottom-ice temperature close to the pressure melting point, induces accelerated migration recrystallization, which results in spatial chemical sorting of the impurities, depending on their state (dissolved vs. solid) and if they are involved or not in salt formation. This chemical sorting effect is responsible for the progressive build-up of the visible solid aggregates that therefore mainly originate "from within", and not from incorporation processes of debris from the ice sheet's substrate. We further discuss how the proposed mechanism is compatible with the other ice properties described. We conclude that the paleoclimatic signal is only marginally affected in terms of global ice properties at the bottom of EPICA Dome C, but that the timescale was considerably distorted by mechanical stretching of MIS20 due to the increasing influence of the subglacial topography, a process that might have started well above the bottom ice. A clear paleoclimatic signal can therefore not be inferred from the deeper part of the EPICA Dome C ice core. Our work suggests that the existence of a flat monotonic ice–bedrock interface, extending for several times the ice thickness, would be a crucial factor in choosing a future "oldest ice" drilling location in Antarctica.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
To assess the 180-day incidence of Staphylococcus aureus infections following orthopedic surgeries using microbiology cultures.
Retrospective observational epidemiology study.
National administrative ...hospital database.
Adult patients with an elective admission undergoing orthopedic surgeries in the inpatient and hospital-based outpatient settings discharged between July 1, 2010, and June 30, 2015.
Patients were identified from 181 hospitals reporting microbiology results to the Premier Healthcare Database. Orthopedic surgeries were defined using International Classification of Disease, Ninth Revision, Clinical Modification (ICD-9-CM) procedure and current procedural terminology (CPT) codes. Microbiology cultures and ICD-9/10 diagnosis codes identified surgical site infections (SSIs), bloodstream infections (BSIs), and other infections associated postoperatively (eg, respiratory and urinary tract infections).
Among 359,268 inpatient orthopedic surgical encounters, the S. aureus infection incidence was 1.13%: SSI, 0.68%; BSI, 0.28%; and other types, 0.17%. Among 292,011 outpatient encounters, the S. aureus incidence was 0.78%: SSI, 0.55%; BSI, 0.12%; and other types, 0.11%. Methicillin-resistant S. aureus (MRSA) infections accounted for 46% and 44% in the respective settings. Plastic/hand-limb reattachment and amputation had the highest overall S. aureus incidence in both settings. S. aureus was the most commonly isolated microorganism among culture-confirmed SSIs (48.0%) and BSIs (35.0%), followed by other Enterobacteriaceae (14.0%) for SSIs and Escherichia spp (12.5%) for BSIs.
These findings suggest that S. aureus infections continue to be an important contributor to the burden of postoperative infections after inpatient and outpatient orthopedic procedures.
The EPICA (European Project for Ice Coring in Antarctica) Dome C drilling in East Antarctica has now been completed to a depth of 3260 m, at only a few meters above bedrock. Here we present the new ...EDC3 chronology, which is based on the use of 1) a snow accumulation and mechanical flow model, and 2) a set of independent age markers along the core. These are obtained by pattern matching of recorded parameters to either absolutely dated paleoclimatic records, or to insolation variations. We show that this new time scale is in excellent agreement with the Dome Fuji and Vostok ice core time scales back to 100 kyr within 1 kyr. Discrepancies larger than 3 kyr arise during MIS 5.4, 5.5 and 6, which points to anomalies in either snow accumulation or mechanical flow during these time periods. We estimate that EDC3 gives accurate event durations within 20% (2σ) back to MIS11 and accurate absolute ages with a maximum uncertainty of 6 kyr back to 800 kyr.
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