Witten's perturbation on strata with general adapted metrics

Let $M$ be a stratum of a compact stratified space $A$. It is equipped with a general adapted metric $g$, which is slightly more general than the adapted metrics of Nagase and Brasselet-Hector-Saralegi. In particular, $g$ has a general type, which is an extension of the type of an adapted metric. A restriction on this general type is assumed, and then $g$ is called good. We consider the maximum/minimun ideal boundary condition, $d_{\text{\rm max/min}}$, of the compactly supported de~Rham complex on $M$, in the sense of Br\"uning-Lesch. Let $H^*_{\text{\rm max/min}}(M)$ and $\Delta_{\text{\rm max/min}}$ denote the cohomology and Laplacian of $d_{\text{\rm max/min}}$. The first main theorem states that $\Delta_{\text{\rm max/min}}$ has a discrete spectrum satisfying a weak form of the Weyl's asymptotic formula. The second main theorem is a version of Morse inequalities using $H_{\text{\rm max/min}}^*(M)$ and what we call rel-Morse functions. An ingredient of the proofs of both theorems is a version for $d_{\text{\rm max/min}}$ of the Witten's perturbation of the de~Rham complex. Another ingredient is certain perturbation of the Dunkl harmonic oscillator previously studied by the authors using classical perturbation theory. Assume that $A$ is a stratified pseudomanifold, and consider its intersection homology $I^{\bar p}H_*(A)$ with perversity $\bar p$; in particular, the lower and upper middle perversities are denoted by $\bar m$ and $\bar n$, respectively. Then, for any perversity $\bar p\le\bar m$, there is an associated good adapted metric on $M$ satisfying the Nagase isomorphism $H^r_{\text{\rm max}}(M)\cong I^{\bar p}H_r(A)^*$ ($r\in\N$). If $M$ is oriented and $\bar p\ge\bar n$, we also get $H^r_{\text{\rm min}}(M)\cong I^{\bar p}H_r(A)$. Thus our version of the Morse inequalities can be described in terms of $I^{\bar p}H_*(A)$.Comment: 46 pages. A few minor corrections were mad

Covariation in oxidative stress markers in the blood of nestling and adult birds

Interest in the imbalance between the production of reactive oxygen species and the state of the antioxidant machinery—that is, oxidative stress—has recently grown among comparative physiologists and evolutionary/behavioral ecologists. The number and types of markers used to estimate oxidative stress is, however, under debate. The study of covariation among these markers is necessary to better interpret the information content of each independent variable. Here, the covariation in levels of 10 blood parameters in a group of zebra finches (Taeniopygia guttata) as nestlings and adults was analyzed across a large data set. Total glutathione levels in erythrocytes were negatively correlated with plasma carotenoid values in nestlings only, supporting the implication of carotenoids in the antioxidant machinery during a particularly stressful period of life. Plasma lipid levels (triglycerides [TRGs]) as well as plasma antioxidant capacity—the latter tested with and without control for uric acid levels—showed individual consistency with age. Plasma TRG and uric acid levels were strongly correlated with plasma lipid peroxidation and antioxidant capacity, respectively, suggesting an influence of recent intake or mobilization of energy stores on these variables. The meaning of oxidative stress markers, whether corrected or uncorrected for levels of nutritional metabolites, remains to be explored. Experiments manipulating diet composition and oxidative stress are necessary to confirm or reject the hypothesized causalities.A.A.R.-H. was funded by a Formación de Personal de Investigación grant (BES-2010-035013; Ministerio de Economía y Competitividad [MINECO], Spanish government). Financial support was obtained from the projects CGL-2009-10883-C02-02 and CGL2012-40229-C02-01 (MINECO).Peer Reviewe

The level of an intracellular antioxidant during development determines the adult phenotype in a bird species: a potential organizer role for glutathione

Life-history traits are often involved in trade-offs whose outcome would depend on the availability of resources but also on the state of specific molecular signals. Early conditions can influence trade-offs and program the phenotype throughout the lifetime, with oxidative stress likely involved in many taxa. Here we address the potential regulatory role of a single intracellular antioxidant in lifehistory trade-offs. Blood glutathione levels were reduced in a large sample of birds (zebra finch Taeniopygia guttata) during development using the synthesis inhibitor buthionine sulfoximine (BSO). Results revealed several modifications in the adult phenotype. BSO-treated nestlings showed lower glutathione and plasma antioxidant levels. In adulthood, BSO birds endured greater oxidative damage in erythrocytes but stronger expression of a sexual signal. Moreover, adult BSO females also showed weaker resistance to oxidative stress but were heavier and showed better body condition. Results suggest that low glutathione values during growth favor the investment in traits that should improve fitness returns, probably in the form of early reproduction. Higher oxidative stress in adulthood may be endured if this cost is paid later in life. Either the presence of specific signaling mechanisms or the indirect effect of increased oxidative stress can explain our findings.Ministerio de Economía y Competitividad [MINECO], Spain). Financial support was obtained from the projects CGL-2009-10883-C02-02 and CGL2012-40229-C02-01 (MINECO).Peer Reviewe

Analysis and Knowledge Discovery by Means of Self-Organizing Maps for Gaia Data Releases

This version of the article has been accepted for publication, after peer review and is subject to Springer Nature’s AM terms of use, but is not the Version of Record and does not reflect post-acceptance improvements, or any corrections. The Version of Record is available online at: http://dx.doi.org/10.1007/978-3-319-46681-1_17Versión final aceptada de: Álvarez, M.A., Dafonte, C., Garabato, D., Manteiga, M. (2016). Analysis and Knowledge Discovery by Means of Self-Organizing Maps for Gaia Data Releases. In: Hirose, A., Ozawa, S., Doya, K., Ikeda, K., Lee, M., Liu, D. (eds) Neural Information Processing. ICONIP 2016. Lecture Notes in Computer Science(), vol 9950. Springer, Cham. https://doi.org/10.1007/978-3-319-46681-1_17[Abstract]: A billion stars: this is the approximate amount of visible objects estimated to be observed by the Gaia satellite, representing roughly 1 % of the objects in the Galaxy. It constitutes the biggest amount of data gathered to date: by the end of the mission, the data archive will exceed 1 Petabyte. Now, in order to process this data, the Gaia mission conceived the Data Processing and Analysis Consortium, which will apply data mining techniques such as Self-Organizing Maps. This paper shows a useful technique for source clustering, focusing on the development of an advanced visualization tool based on this technique

Errors in the measurement systems with the inclusion of single-phase loads at 220V in three-phase distribution networks

[EN] This research analyzes the problems presented by the measurement systems in one Phase three wires electrical distribution networks when single-phase loads are connected to 220V and proposes to replace the equation to eliminate the error that occurs in the energy meter. This case of study was given in Ecuador due to the massive inclusion of induction cookers through the change of the energy matrix promoted by the state since this account with more than 90 of hydroelectric energy to meet their electric demand. It is important to explain that this research does not include in the state of the art the problem and the solutions, because of this novelty was presented promptly in Ecuador due to the technical conditions of the energy distribution system, at the voltage level versus the construction voltage of the single-phase loads that in the case of induction, cookers were imported from countries that handle 220V single-phase voltages. This consequence does not present a choice, it is ethical for those responsible for the measurement systems of the Utility, to present a solution to the inconvenience of how it is developed in this investigation.This work was supported by Universitat Politectica de Valencia in Valencia (Spain), the Smart University 2.0 Research Group of the Universidad Catolica de Cuenca (Ecuador), and the Utility CENTROSUR for the data, equipment and laboratory to perform the tests (Ecuador).Toledo, MA.; Álvarez, C.; Morales, DX.; Arias, C. (2019). Errors in the measurement systems with the inclusion of single-phase loads at 220V in three-phase distribution networks. IEEE. 1-7. https://doi.org/10.1109/CHILECON47746.2019.8987564S1

A comparison of robust Kalman filtering methods for artifact correction in heart rate variability analysis

La variabilidad de la frecuencia cardiaca (HRV) ha recibido una atención considerable por mucho años, ya que esta proporciona un valor cuantitativo para examinar el ritmo sinusal modulado para el sistema nervioso autónomo (SNA). El SNA juega un papel importante en campos clínicos y fisiológicos. El análisis de la HRV se puede realizar calculando varias medidas tanto en el domino del tiempo como en la frecuencia. Sin embargo, el cálculo de estas medidas se puede ver afectado por la presencia de artefactos o latidos ectópicos en registros de electrocardiogramas (ECG). Esto es particularmente cierto para registros ECG desde un monitor Holter. El objetivo de este trabajo fue estudiar el rendimiento de varios filtros de Kalman robustos para la corrección de artefactos. Para nuestros experimentos, se usaron dos bases de datos reales: el primer conjunto de datos incluye 10 series de tiempo de intervalos RR a partir de un generador de series de tiempo de intervalos RR realista. La segunda base de datos contiene 10 conjuntos de series de intervalos RR de cinco pacientes sanos y cinco pacientes que sufren una insuficiencia cardiaca congestiva. Se calculó la desviación estándar de los intervalos RR a partir de las señales filtradas. Los resultados se compararon con un reconocido software de procesamiento, mostrando comportamientos y valores similares. Adicionalmente, los métodos propuestos ofrecen resultados satisfactorios en comparación con el filtro de Kalman estándar.Heart rate variability (HRV) has received considerable attention for many years, since it provides a quantitative marker for examining the sinus rhythm modulated by the autonomic nervous system (ANS). The ANS plays an important role in clinical and physiological fields. HRV analysis can be performed by computing several time and frequency domain measurements. However, the computation of such measurements can be affected by the presence of artifacts or ectopic beats in the electrocardiogram (ECG) recording. This is particularly true for ECG recordings from Holter monitors. The aim of this work was to study the performance of several robust Kalman filters for artifact correction in Inter-beat (RR) interval time series. For our experiments, two data sets were used: the first data set included 10 RR interval time series from a realistic RR interval time series generator. The second database contains 10 sets of RR interval series from five healthy patients and five patients suffering from congestive heart failure. The standard deviation of the RR interval was computed over the filtered signals. Results were compared with a state of the art processing software, showing similar values and behavior. In addition, the proposed methods offer satisfactory results in contrast to standard Kalman filtering

Modelling the spatial variation of vital rates: An evaluation of the strengths and weaknesses of correlative species distribution models

P. 841-853Aim: Species distribution models based on breeding occurrence data allow for identifying both environmental drivers and geographic areas potentially relevant for breeding. However, the interpretation of model predictions in terms of reproductive performance should be further investigated, as this information is crucial for conservation planning. We evaluated the strengths and weaknesses of a correlative modelling approach based on breeding occurrence data (presence–absence) against another approach based on vital rates’ data (breeding success) for gaining insights on species persistence in the case of Great Bustards (Otis tarda). Location: Spain. Methods: Breeding occurrence and breeding success were independently modelled using generalized linear models and multimodel inference analyses. Sensitivities to the way in which the population parameter (breeding success) was defined were explored by building five versions of the dependent variable. We evaluated differences in model performance and identified areas of congruence for breeding occurrence and breeding success. Results: The agreement between the spatial predictions achieved by breeding occurrence and breeding success models differed substantially across databases, with the largest differences in occupied breeding areas. The deviance explained by the breeding occurrence model was 64.98% and ranged from 7.83% to 62.27% for the breeding success models. Model performance was higher for models calibrated within potential than within occupied breeding areas. Main conclusions: The combination of data on both breeding occurrence and breeding success into a species distribution modelling framework showed the limitations of breeding occurrence models for inferring reproductive parameters. The definition of the population parameter as dependent variable was a key factor that strongly affected the inference of vital rates’ models. The approach allowed for discriminating between areas and landscape attributes necessary for the long-term species persistence from others that may be relevant, but not so much for reproductive performance