A mathematical model of interleukin-6 dynamics during exercise

Physical exercise is known to reduce the chronic inflammatory status that leads to Type 2 Diabetes. Its beneficial effects seem to be exerted trough a primary production of the cytokine Interleukin-6 (IL-6) which triggers a cascade of anti-inflammatory cytokines. Consequently, IL-6 has a central role in the description of the metabolic effects of exercise. The aim of this study was to develop a model of IL-6 dynamics during exercise. A model constituted by two non-linear differential equations is proposed. Since IL-6 production seems to be dependent not only on exercise duration but also on exercise intensity, input to the model is represented by heart rate, which is known to correlate well with exercise intensity. Model implementation in a Matlab-based parametric identification procedure allowed optimization of adjustable characteristic coefficients of IL-6 dynamics during exercise. From the reported results, it can be concluded that this model is a suitable tool to reproduce IL-6 time course during the execution of a physical exercise. This model was the first step of a project aimed at describing the complete immune system response to exercise and at giving a comprehensive sight of the effects that exercise has on the metabolic system

Estimation of Tidal Volume during Exercise Stress Test from Wearable-Device Measures of Heart Rate and Breathing Rate

Tidal volume (TV), defined as the amount of air that moves in or out of the lungs with each respiratory cycle, is important in evaluating the respiratory function. Although TV can be reliably measured in laboratory settings, this information is hardly obtainable under everyday living conditions. Under such conditions, wearable devices could provide valuable support to monitor vital signs, such as heart rate (HR) and breathing rate (BR). The aim of this study was to develop a model to estimate TV from wearable-device measures of HR and BR during exercise. HR and BR were acquired through the Zephyr Bioharness 3.0 wearable device in nine subjects performing incremental cycling tests. For each subject, TV during exercise was obtained with a metabolic cart (Cosmed). A stepwise regression algorithm was used to create the model using as possible predictors HR, BR, age, and body mass index; the model was then validated using a leave-one-subject-out cross-validation procedure. The performance of the model was evaluated using the explained variance (R-2), obtaining values ranging from 0.65 to 0.72. The proposed model is a valid method for TV estimation with wearable devices and can be considered not subject-specific and not instrumentation-specific

Perilaku Inovasi Karyawan Ditinjau Dari Empat Kuadran Iklim Organisasi

Penelitian ini bertujuan untuk melihat hubungan antara iklim organisasi denganperilaku inovasi karyawan. Penelitian ini menggunakan pendekatan kuantitatif denganmetode korelasional, melibatkan 36 orang karyawan yang bekerja di harian Tribun Medandan teknik pengambilan sampel menggunakan nonrandom sampling yaitu conviniencesampling. Hasil penelitian menunjukkan bahwa iklim organisasi memiliki tiga kuadran yangberhubungan dengan perilaku inovasi yaitu kuadran human relation model, rational goalmodel dan open system model, sedangkan satu kuadran lainnya yaitu internal process modeltidak menunjukkan adanya pengaruh dengan perilaku inovasi. Berdasarkan hasil penelitianini dapat disimpulkan bahwa untuk meningkatkan perilaku inovasi karyawan di suatuperusahaan, maka pihak manajemen patut pula untuk memperhitungan iklim organisasi yangberkembang di Perusahaannya

Initial investigation of athletes’ electrocardiograms acquired by wearable sensors during the pre-exercise phase

Aim: The aim of this study is to support large-scale prevention programs fighting sport-related sudden cardiac death by providing a set of electrocardiographic features representing a starting point in the development of normal reference values for the pre-exercise phase. Background: In people with underlying, often unknown, cardiovascular abnormalities, increased cardiovascular load during exercise can trigger sport-related sudden cardiac death. Prevention remains the only weapon to contrast sport-related sudden cardiac death. So far, no reference values have been proposed for electrocardiograms of athletes acquired with wearable sensors in the pre-exercise phase, consisting of the few minutes immediately before the beginning of the training session. Objective: To perform an initial investigation of athletes’ electrocardiograms acquired by wearable sensors during the pre-exercise phase. Methods: The analyzed electrocardiograms, acquired through BioHarness 3.0 by Zephyr, belong to 51 athletes (Sport Database and Cycling Database of the Cardiovascular Bioengineering Lab of the Università Politecnica delle Marche, Italy). Preliminary values consist of interquartile ranges of six electrocardiographic features which are heart rate, heart-rate variability, QRS duration, ST level, QT interval, and corrected QT interval. Results: For athletes 35 years old or younger, preliminary values were [72;91]bpm, [26;47]ms, [85;104]ms, [-0.08;0.08]mm, [326;364]ms and [378;422]ms, respectively. For athletes older than 35 years old, preliminary values were [71;94]bpm, [16;65]ms, [85;100]ms, [-0.11;0.07]mm, [330;368]ms and [394;414]ms, respectively. Conclusion: Availability of preliminary reference values could help identify those athletes who, due to electrocardiographic features out of normal ranges, are more likely to develop cardiac complications that may lead to sport-related sudden cardiac death

UN ESTUDIO DESCRIPTIVO DEL PERFIL DE LOS ASPIRANTES A LAS CARRERAS DE CIENCIAS ECONÓMICAS Y SOCIALES

Actualmente el ingreso universitario constituye un tema importante en la gestión universitaria. Ya sea desde las áreas de ingreso de: las unidades académicas, la unidad central de la Universidad o la Secretaría de Políticas Universitarias dependiente del Ministerio de Educación, realizándose acciones conjuntas con el nivel de Educación Superior en cuanto a financiamiento de proyectos de articulación. Reconociendo que el diagnóstico de las debilidades de las instituciones educativas es el aislamiento en que desarrollan su tarea, debemos dotar a las gestiones de herramientas que transformen dicha debilidad en una fortaleza, posibilitando: encuentros, préstamos cognitivos y soluciones solidarias, generando acciones que favorezcan las enseñanzas en ese sentido. Además, la gestión universitaria tiene como propósito dotar al alumnado de herramientas para su eficaz desenvolvimiento en el campo profesional y científico, siendo condición necesaria que el aspirante reúna determinados requisitos mínimos de conocimientos y aptitudes que le permitan desenvolverse exitosamente. Este trabajo pretende identificar grupos de aspirantes con características comunes en cuanto a su desempeño en los exámenes de admisión, utilizando una técnica multivariante de análisis exploratorio, el análisis cluster, a fin de obtener una clasificación que resulte relevante para la adopción de políticas conducentes al mejoramiento de la calidad educativa

Long-range correlation and multifractality in Bach's Inventions pitches

We show that it can be considered some of Bach pitches series as a stochastic process with scaling behavior. Using multifractal deterend fluctuation analysis (MF-DFA) method, frequency series of Bach pitches have been analyzed. In this view we find same second moment exponents (after double profiling) in ranges (1.7-1.8) in his works. Comparing MF-DFA results of original series to those for shuffled and surrogate series we can distinguish multifractality due to long-range correlations and a broad probability density function. Finally we determine the scaling exponents and singularity spectrum. We conclude fat tail has more effect in its multifractality nature than long-range correlations.Comment: 18 page, 6 figures, to appear in JSTA

A new scenario for the Domerian-Toarcian transition

Pour tenter de mieux comprendre l’événement d’anoxie océanique globale au Toarcien inférieur, il convient de remonter aux changements environnementaux qui ont précédé cette phase paroxysmale. En effet, la comparaison des séquences sédimentaires et biostratigraphiques du passage Domérien-Toarcien entre la Téthys occidentale (Maroc, Espagne, Portugal) et l’Europe du Nord-Ouest (Causses, Allemagne, Angleterre) fait apparaître une importante lacune dans la région septentrionale. La faune d’Arieticeratinae (Emaciaticeras, Canavaria, Fontanelliceras) et d’Harpoceratinae (Lioceratoides, Neolioceratoides), accompagnée ensuite de Dactylioceras particuliers (groupe mirabile-polymorphum = sous-genre Eodactylites), fait presque totalement défaut en Europe du Nord-Ouest, alors qu’elle abonde dans les dernières alternances marno-calcaires, sans changement lithologique notable avec le Domérien des coupes téthysiennes. Cette faune est intercalée entre les derniers Pleuroceras et les Dactylioceras du groupe tenuicostatum. Ces derniers apparaissent dans les argiles succédant immédiatement au dernier banc calcaire à Dactylioceras mirabile au Portugal notamment. C’est là le diachronisme déjà reconnu entre les limites lithostratigraphique (disparition des bancs calcaires) et biostratigraphique (apparition du genre Dactylioceras) au passage Domérien-Toarcien. Cette observation peut s’intégrer dans un nouveau scénario paléo-océanographique prenant en compte à la fois la tendance régressive majeure du Domérien supérieur (conduisant à une lacune régionale importante), l’abondance de matière charbonneuse dans les premiers dépôts transgressifs du Toarcien et l’événement anoxique global subséquent. Dans la partie supérieure du Domérien, l’existence d’un fort volcanisme peut être déduite des données relatives aux variations des isotopes du strontium [McArthur et al., 2000]. A ce pic de strontium sont associées une faible anomalie négative du δ13 C à la limite Domérien-Toarcien et des valeurs particulièrement élevées du δ18 O [Morettini et Bartolini, 1999]. Nous pensons que cette activité volcanique débute par des émissions massives de SO2 induisant des pluies acides, un obscurcissement et un refroidissement. A cette phase de refroidissement correspond une augmentation de l’englacement des pôles et une régression responsable de la lacune majeure évoquée plus haut, particulièrement sensible dans les mers épicontinentales. Bien que les preuves directes d’une glaciation fini-domérienne fassent actuellement défaut [Hallam, 2001], le glacio-eustatisme nous semble le seul mécanisme permettant d’expliquer une oscillation marine importante mais de courte durée [Brandt, 1986 ; Dewey et Pitman, 1998]. En effet, le cycle régression-transgression s’étale sur environ deux zones d’ammonites, la lacune sédimentaire en elle-même recouvrant essentiellement les sous-zones à Elisa et Mirabile. Ce premier épisode serait suivi, dans la zone à Tenuicostatum, par une importante perturbation du cycle du carbone responsable d’un effet de serre. Le réchauffement, provoquerait alors la transgression bien connue du Toarcien inférieur, cachetant le hiatus sédimentaire dans la province nord-ouest européenne. L’intervalle de temps correspondant à cette lacune aurait permis à la végétation de coloniser les immenses surfaces nouvellement émergées. C’est le lessivage et l’oxydation de la matière organo-humique et bactérienne accumulée pendant cette période, associée à une élévation de la température, qui aurait enclenché le mécanisme d’anoxie lors du paroxysme de la transgression

Enhanced adaptive matched filter for automated identification and measurement of electrocardiographic alternans

Electrocardiographic alternans, consisting of P-wave alternans (PWA), QRS-complex alternans (QRSA) and Twave alternans (TWA), is an index of cardiac risk. However, only automated TWA measurement methods have been proposed so far. Here, we presented the enhanced adaptive matched filter (EAMF) method and tested its reliability in both simulated and experimental conditions. Our methodological novelty consists in the introduction of a signal enhancement procedure according to which all sections of the electrocardiogram (ECG) but the wave of interest are set to baseline, and in the extraction of the alternans area (AAr) in addition to the standard alternans amplitude (AAm). Simulated data consisted of 27 simulated ECGs representing all combinations of PWA, QRSA and TWA of low (10 mu V) and high (100 mu V) amplitude. Experimental data consisted of exercise 12-lead ECGs from 266 heart failure patients with an implanted cardioverter defibrillator for primary prevention. EAMF was able to accurately identify and measure all kinds of simulated alternans (absolute maximum error equal to 2%). Moreover, different alternans kinds were simultaneously present in the experimental data and EAMF was able to identify and measure all of them (AAr: 545 mu V x ms, 762 mu V x ms and 1382 mu V x ms; AAm: 5 mu V, 9 mu V and 7 mu V; for PWA, QRSA and TWA, respectively) and to discriminate TWA as the prevalent one (with the highest AAr). EAMF accurately identifies and measures all kinds of electrocardiographic alternans. EAMF may support determination of incremental clinical utility of PWA and QRSA with respect to TWA only.Cardiolog

Advanced repeated structuring and learning procedure to detect acute myocardial ischemia in serial 12-lead ECGs

Objectives. Acute myocardial ischemia in the setting of acute coronary syndrome (ACS) may lead to myocardial infarction. Therefore, timely decisions, already in the pre-hospital phase, are crucial to preserving cardiac function as much as possible. Serial electrocardiography, a comparison of the acute electrocardiogram with a previously recorded (reference) ECG of the same patient, aids in identifying ischemia-induced electrocardiographic changes by correcting for interindividual ECG variability. Recently, the combination of deep learning and serial electrocardiography provided promising results in detecting emerging cardiac diseases; thus, the aim of our current study is the application of our novel Advanced Repeated Structuring and Learning Procedure (AdvRS&LP), specifically designed for acute myocardial ischemia detection in the pre-hospital phase by using serial ECG features. Approach. Data belong to the SUBTRACT study, which includes 1425 ECG pairs, 194 (14%) ACS patients, and 1035 (73%) controls. Each ECG pair was characterized by 28 serial features that, with sex and age, constituted the inputs of the AdvRS&LP, an automatic constructive procedure for creating supervised neural networks (NN). We created 100 NNs to compensate for statistical fluctuations due to random data divisions of a limited dataset. We compared the performance of the obtained NNs to a logistic regression (LR) procedure and the Glasgow program (Uni-G) in terms of area-under-the-curve (AUC) of the receiver-operating-characteristic curve, sensitivity (SE), and specificity (SP). Main Results. NNs (median AUC = 83%, median SE = 77%, and median SP = 89%) presented a statistically (P value lower than 0.05) higher testing performance than those presented by LR (median AUC = 80%, median SE = 67%, and median SP = 81%) and by the Uni-G algorithm (median SE = 72% and median SP = 82%). Significance. In conclusion, the positive results underscore the value of serial ECG comparison in ischemia detection, and NNs created by AdvRS&LP seem to be reliable tools in terms of generalization and clinical applicability.Cardiolog

Measurement and Interpretation of Fermion-Pair Production at LEP energies above the Z Resonance

This paper presents DELPHI measurements and interpretations of cross-sections, forward-backward asymmetries, and angular distributions, for the e+e- -> ffbar process for centre-of-mass energies above the Z resonance, from sqrt(s) ~ 130 - 207 GeV at the LEP collider. The measurements are consistent with the predictions of the Standard Model and are used to study a variety of models including the S-Matrix ansatz for e+e- -> ffbar scattering and several models which include physics beyond the Standard Model: the exchange of Z' bosons, contact interactions between fermions, the exchange of gravitons in large extra dimensions and the exchange of sneutrino in R-parity violating supersymmetry.Comment: 79 pages, 16 figures, Accepted by Eur. Phys. J.