In this paper, we studied and validated a simple heart beat classifier based on ECG feature models selected with the focus on an improved generalization capability. We considered features from the RR ...series, as well as features computed from the ECG samples and different scales of the wavelet transform, at both avail able leads. The classification performance and generalization were studied using publicly available databases: the MIT-BIH Arrhythmia, the MIT-BIH Supraventricular Arrhythmia, and the St. Pe tersburg Institute of Cardiological Technics (INCART) databases. The Association for the Advancement of Medical Instrumentation recommendations for class labeling and results presentation were followed. A floating feature selection algorithm was used to obtain the best performing and generalizing models in the training and validation sets for different search configurations. The best model found comprehends eight features, was trained in a partition of the MIT-BIH Arrhythmia, and was evaluated in a completely disjoint partition of the same database. The results obtained were: global accuracy of 93%; for normal beats, sensitivity (S) 95%, positive predictive value (P + ) 98%; for supraventricular beats, S 11%, P + 39%; and for ventricular beats S 81%, P + 87%. In order to test the generalization capability, performance was also evaluated in the INCART, with results comparable to those obtained in the test set. This classifier model has fewer features and performs better than other state-of-the-art methods with results suggesting better generalization capability.
Gender‐responsive budgeting (GRB) has been introduced in over 80 countries to mitigate gender inequities. We evaluate if these reforms can influence policy making and enhance gender‐oriented ...accountability. Our analysis follows the process‐tracing methodology and includes over 20 in‐depth interviews. Our findings show significant public administration obstacles to GRB, but success is possible in institutions with proper leadership, human, and technological resources. This study advances our understanding of the operational limits of GRB, highlights areas for future research on equity‐oriented reforms, and sheds light on issues that practitioners need to account for as they strive to further gender equity.
Resumen
El presupuesto sensible al género (GRB, por sus siglas en inglés) se ha introducido en más de 80 países para mitigar las desigualdades de género. En este estudio evaluamos si estas reformas pueden influir en la formulación de políticas y mejorar la rendición de cuentas orientada al género. Nuestro análisis se basa en la metodología de process‐tracing e incluye más de veinte entrevistas en profundidad. Nuestros hallazgos muestran que debilidades de la administración pública resultan en obstáculos significativos para el GRB, pero también que las reformas de GRB pueden ser exitosas en instituciones con los niveles apropiados de liderazgo, recursos humanos y sistemas tecnológicos. Este estudio avanza nuestra comprensión de los límites operativos del GRB, destaca áreas para futuras investigaciones sobre reformas orientadas a la equidad y clarifica los obstáculos que los funcionarios públicos deben tener en cuenta a medida que se esfuerzan por promover la equidad de género.
The stabilization of elusive monomeric species containing multiple boron‐chalcogen bonds has motivated the investigation of sophisticated ligand systems in the past few years. Recently, a series of ...neutral, Lewis acid‐free chalcogenboranes were prepared by incorporation of an amido imidazoline‐2‐imine as the supporting ligand (Frank et al., Angew. Chem. Int. Ed. 2021, 60, 4633), resulting in well‐defined molecular entities with pronounced multiple bond character, B=X (X=O, S, Se, Te). In view of the potential use of N‐heterocyclic boranes (NHB=X) as ligands in catalysis and fine chemistry, we evaluated in this work the bonding properties of the new B=X compounds based on a π‐backdonation model. The electronic properties of systems in question were modulated via systematic modifications of the NHB ring with respect to ligand variation, saturation, size, and heteroatom substitutions. Investigations into the B=X bond length and order, calculated by means of density functional theory methods, reveal enhanced B=X bonding properties for NHB rings with high electron delocalization in the NHB ring and bearing electron‐withdrawing substituents; a fact that was also confirmed by computational assessment of electron interactions of the B=X species with a dicarbonyl manganese complex. We expect that the analysis will contribute to the rational optimization of existing ligands as well as the development of new moieties, which would further allow for exploration of new boron chemistry.
Electronic effects in the boron‐chalcogen multiple bonds through ligand variation of a series of new chalcogenboranes stabilized by N,N’‐chelating amido imidazoline‐2‐imine ligands were studied by DFT approach. Electron‐withdrawing substituents and electron delocalization yield the shortest B=X bond lengths and the highest B=X bond orders.
This study tackles the ECG classification problem by means of a methodology, which is able to enhance classification performance while simultaneously reducing the computational resources, making it ...specially adequate for its application in the improvement of ambulatory settings. For this purpose, the sequential forward floating search (SFFS) algorithm is applied with a new criterion function index based on linear discriminants. This criterion has been devised specifically to be a quality indicator in ECG arrhythmia classification. Based on this measure, a comprehensive feature set is analyzed with the SFFS algorithm, and the most suitable subset returned is additionally evaluated with a multilayer perceptron (MLP) to assess the robustness of the model. Aiming at obtaining meaningful estimates of the real-world performance and facilitating comparison with similar studies, the present contribution follows the Association for the Advancement of Medical Instrumentation standard EC57:1998 and the same interpatient division scheme used in several previous studies. Results show that by applying the proposed methods, the performance obtained in similar studies under the same constraints can be exceeded, while keeping the requirements suitable for ambulatory monitoring.
The dissociative mechanism of initiation for a series of Hoveyda‐Grubbs type metathesis catalysts modified at the para and meta positions in the isopropoxybenzylidene ligand is investigated by means ...of DFT calculations. The electron donating/withdrawing capacity of the ligand was screened through the incorporation of various substituents such as halogens, nitro, alkoxides, ketones, esters, amines, and amides. Variations in structural parameters, energy barriers for the Ru−O bond dissociation, and Ru−O bond strength were examined as a function of the Hammett constant. It was found that electronic properties of the catalysts such as chemical potential, hardness, and electrophilicity correlate linearly with the dissociative energy barriers. These findings enable a systematic rationalization and prediction of rate of precatalyst initiation through the calculation of only the HOMO‐LUMO gap of catalysts, as the faster the initiation, the more electrophilic the catalyst.
The initiation rate of olefin metathesis evaluated through a dissociative mechanism is rationalized and predicted by means of the electrophilicity of the Hoveyda‐Grubbs catalyst, as the faster the initiation, the more electrophilic the catalyst.
This study aimed to determine the effects of exogenous application of salicylic acid (SA) on the toxic effects of salt in relation to ethylene and polyamine synthesis, and to correlate these traits ...with the expression of genes involved in ethylene and polyamine metabolism in two tomato species differing in their sensitivity to salt stress, Solanum lycopersicum cv Ailsa Craig and its wild salt‐resistant relative Solanum chilense. In S. chilense, treatment with 125 mM NaCl improved plant growth, increased production of ethylene, endogenous salicylic acid and spermine. The production was related to a modification of expression of genes involved in ethylene and polyamine metabolism. In contrast, salinity decreased plant growth in S. lycopersicum without affecting endogenous ethylene, salicylic or polyamine concentrations. Exogenous application of salicylic acid at 0.01 mM enhanced shoot growth in both species and affected ethylene and polyamine production in S. chilense. Concomitant application of NaCl and salicylic acid improved osmotic adjustment, thus suggesting that salt and SA may act in synergy on osmolyte synthesis. However, the beneficial impact of exogenous application of salicylic acid was mitigated by salt stress since NaCl impaired endogenous SA accumulation in the shoot and salicylic acid did not improve plant growth in salt‐treated plants. Our results thus revealed that both species respond differently to salinity and that salicylic acid, ethylene and polyamine metabolisms are involved in salt resistance in S. chilense.
While R2C=N−R double bonds in organic imines are well established, the related iminoboranes R‐B=N−R are either prone to oligomerization or can only be stabilized at sufficient steric congestion. In ...particular, the examples of unsubstituted parent B=N‐H entity are rare. We demonstrate that the amino imidazoline‐2‐imine ligand system (HAmIm) not only gives rise to the isolation of a parent (AmIm)B=N−H iminoborane, but also to species of type (AmIm)B=N‐SiMe3 with concomitant stabilization by lithium bromide. The double bond character in these systems is unambiguously corroborated by DFT calculations. The steric accessibility of the (AmIm)B=NH unit allows facile reactivity including metathesis reactions with C=O and C=S bonds, nucleophilic addition toward organic and organometallic carbonyl compounds, but also oxidative N−N coupling within a dimeric unit. Thus, the chemical behavior of the (AmIm)B=N−H and (AmIm)B=N‐SiMe3 is distinctly different from that of organic imines.
Imine or not Imine? We present a rare example of a parent iminoborane with the unfunctionalized B=NH entity. The reactivity of this rare compound class shows remarkable differences to boron's neighbor element carbon as found in organic imines.
Predictive catalysis must be the tool that does not replace experiments, but acts as a selective agent, so that synthetic strategies of maximum profitability are used in the laboratory in a surgical ...way. Here, nanotechnology has been used in olefin metathesis from homogeneous Ru‐NHC catalysts, specifically annulating a C60 fullerene to the NHC ligand. Based on results with the C60 in the backbone, a sterile change with respect to the catalysis of the metal center, an attempt has been made to bring C60 closer to the metal, by attaching it to one of the two C−N bonds of the imidazole group of the SIMes (1,3‐bis(2,4,6‐trimethylphenyl)imidazolin‐2‐ylidene) ligand (reference NHC ligand of the 2nd generation Grubbs catalysts) to increase the steric pressure of C60 in the first sphere of reactivity of the metal. The DFT calculated thermodynamics and the kinetics of SIMes‐derived systems show that they are efficient catalysts for olefin metathesis.
Annulating C60 fullerenes in NHC ligands enhances the catalysis of Ru‐based olefin metathesis catalysis.
A decade of genetic association studies in multiple organisms suggests that most complex traits are polygenic; that is, they have a genetic architecture determined by numerous loci, each with small ...effect‐size. Thus, determining the degree of polygenicity and its variation across traits, environments and time is crucial to understand the genetic basis of phenotypic variation. We applied multilocus approaches to estimate the degree of polygenicity of fitness‐related traits in a long‐lived plant (Pinus pinaster Ait., maritime pine) and to analyse this variation across environments and years. We evaluated five categories of fitness‐related traits (survival, height, phenology, functional, and biotic‐stress response) in a clonal common‐garden network planted in contrasted environments (over 20,500 trees). Most of the analysed traits showed evidence of local adaptation based on Qst–Fst comparisons. We further observed a remarkably stable degree of polygenicity, averaging 6% (range of 0%–27%), across traits, environments and years. We detected evidence of negative selection, which could explain, at least partially, the high degree of polygenicity. Because polygenic adaptation can occur rapidly, our results suggest that current predictions on the capacity of natural forest tree populations to adapt to new environments should be revised, especially in the current context of climate change.
PDF