Explore the vast range of titles available.

Spiking neural networks combine analog computation with event-based communication using discrete spikes. While the impressive advances of deep learning are enabled by training non-spiking artificial neural networks using the backpropagation algorithm, applying this algorithm to spiking networks was previously hindered by the existence of discrete spike events and discontinuities. For the first time, this work derives the backpropagation algorithm for a continuous-time spiking neural network and a general loss function by applying the adjoint method together with the proper partial derivative jumps, allowing for backpropagation through discrete spike events without approximations. This algorithm, EventProp, backpropagates errors at spike times in order to compute the exact gradient in an event-based, temporally and spatially sparse fashion. We use gradients computed via EventProp to train networks on the Yin-Yang and MNIST datasets using either a spike time or voltage based loss function and report competitive performance. Our work supports the rigorous study of gradient-based learning algorithms in spiking neural networks and provides insights toward their implementation in novel brain-inspired hardware.

Nations have been competing in sporting competitions for centuries. Therefore, explaining the success of different countries has a long history in sports science. At first, researchers tried to explain success patterns with the help of divergent geographical factors. Later, literature included other determinants on the macro-level which provide evidence that especially the GDP as a proxy for the prosperity of a country has a significant impact on success in sports. Within this broader field of research, also specialization patterns in sports developed into an important topic of research. In line with the literature on factors which lead to (national) success, so far, the discussion mostly concentrates on determinants on a macro-level. We identify the problem that different specialization patterns can be observed in countries that have similar factors on the macro-level, as well. There seems to be a research gap concerning the influencing factors on a meso-level. As a result, the aim of this paper is to show which determinants on the meso-level can affect sports specialization patterns. We provide a model based on the findings of lobbying theory that explains not only different specialization patterns between, e.g., Europe and Africa, but also different specialization patterns within a continent and dissimilar patterns of countries with a similar macro-level can be understood. Overall, our paper contributes to the discussion on specialization in elite sports from an economic perspective, so that future research can build on our work, in particular concerning empirical tests of our approach.

Immunofluorescence microscopy is routinely used in the diagnosis of and research on renal impairments. However, this highly specific technique is restricted in its maximum resolution to about 250 nm in the lateral and 700 nm in the axial directions and thus not sufficient to investigate the fine subcellular structure of the kidney’s glomerular filtration barrier. In contrast, electron microscopy offers high resolution, but this comes at the cost of poor preservation of immunogenic epitopes and antibody penetration alongside a low throughput. Many of these drawbacks were overcome with the advent of super-resolution microscopy methods. So far, four different super-resolution approaches have been used to study the kidney: single-molecule localization microscopy (SMLM), stimulated emission depletion (STED) microscopy, structured illumination microscopy (SIM), and expansion microscopy (ExM), however, using different preservation methods and widely varying labelling strategies. In this work, all four methods were applied and critically compared on kidney slices obtained from samples treated with the most commonly used preservation technique: fixation by formalin and embedding in paraffin (FFPE). Strengths and weaknesses, as well as the practicalities of each method, are discussed to enable users of super-resolution microscopy in renal research make an informed decision on the best choice of technique. The methods discussed enable the efficient investigation of biopsies stored in kidney banks around the world.

The addressing of a particular qubit within a quantum register is a key pre-requisite for scalable quantum computing. In general, executing a quantum gate with a single qubit, or a subset of qubits, affects the quantum states of all other qubits. This reduced fidelity of the whole-quantum register could prevent the application of quantum error correction protocols and thus preclude scalability. Here we demonstrate addressing of individual qubits within a quantum byte (eight qubits) and measure the error induced in all non-addressed qubits (cross-talk) associated with the application of single-qubit gates. The quantum byte is implemented using microwave-driven hyperfine qubits of (171)Yb(+) ions confined in a Paul trap augmented with a magnetic gradient field. The measured cross-talk is on the order of 10(-5) and therefore below the threshold commonly agreed sufficient to efficiently realize fault-tolerant quantum computing. Hence, our results demonstrate how this threshold can be overcome with respect to cross-talk.

Extrinsic cues trigger the local translation of specific mRNAs in growing axons via cell surface receptors. The coupling of ribosomes to receptors has been proposed as a mechanism linking signals to local translation but it is not known how broadly this mechanism operates, nor whether it can selectively regulate mRNA translation. We report that receptor-ribosome coupling is employed by multiple guidance cue receptors and this interaction is mRNA-dependent. We find that different receptors associate with distinct sets of mRNAs and RNA-binding proteins. Cue stimulation of growing Xenopus retinal ganglion cell axons induces rapid dissociation of ribosomes from receptors and the selective translation of receptor-specific mRNAs. Further, we show that receptor-ribosome dissociation and cue-induced selective translation are inhibited by co-exposure to translation-repressive cues, suggesting a novel mode of signal integration. Our findings reveal receptor-specific interactomes and suggest a generalizable model for cue-selective control of the local proteome.

The morphological changes that occur in myxomatous mitral valve disease (MMVD) involve various components, ultimately leading to the impairment of mitral valve (MV) function. In this context, intrinsic mitral annular abnormalities are increasingly recognized, such as a mitral annular disjunction (MAD), a specific anatomical abnormality whereby there is a distinct separation between the mitral annulus and the left atrial wall and the basal portion of the posterolateral left ventricular myocardium. In recent years, several studies have suggested that MAD contributes to myxomatous degeneration of the mitral leaflets, and there is growing evidence that MAD is associated with ventricular arrhythmias and sudden cardiac death. In this review, the morphological characteristics of MAD and imaging tools for diagnosis will be described, and the clinical and functional aspects of the coincidence of MAD and myxomatous MVP will be discussed.

Background The right ventricle (RV) and tricuspid valve (TV) have historically been neglected in cardiovascular research and clinical practice. However, growing evidence has established RV dysfunction and tricuspid regurgitation (TR) as independent predictors of mortality and morbidity across a range of cardiac pathologies. The emergence of transcatheter tricuspid valve interventions (TTVI) has further emphasized the need for accurate and reproducible assessment of RV function in the presence of TR. Objective To provide a comprehensive review of current echocardiographic approaches of RV assessment in the context of TR. This review highlights their strengths, limitations, and clinical relevance. We focus particularly on advanced imaging modalities and their role in patient selection and outcome prediction following TTVI. Methods We review contemporary literature on RV anatomy and pathophysiology and critically evaluate echocardiographic modalities, including two-dimensional (2D) indices, three-dimensional (3D) volumetry, strain imaging, and noninvasive RV-pulmonary artery (PA) coupling surrogates, for their role in diagnosing RV dysfunction, guiding risk stratification, and predicting clinical outcomes in patients considered for TTVI. Results Conventional echocardiographic measures of RV function such as tricuspid annular plane systolic excursion (TAPSE) and fractional area change (FAC) are limited by geometric assumptions, regional motion bias, and load dependence. Emerging echocardiographic techniques, including 3D imaging, free wall longitudinal strain (FWLS), effective RV ejection fraction (eRVEF), and RV-PA coupling indices, demonstrate improved accuracy and prognostic utility. In patients with TR, progressive RV remodeling, altered contraction patterns, and altered ventricular interdependence contribute to clinical decompensation. While TTVI provides hemodynamic and symptomatic benefit, it can also reveal latent RV dysfunction, underscoring the importance of thorough pre- and postprocedural evaluation. Conclusion Accurate assessment of RV structure and function is critical for optimal management of TR, particularly in candidates for TTVI. A multiparametric echocardiographic strategy that integrates advanced imaging techniques with functional indices provides a more complete characterization of RV performance, supports procedural planning, and improves risk stratification. Future research should aim to establish TR-specific thresholds, validate emerging functional markers, and develop standardized, evidence-based algorithms to guide clinical decision-making.

This paper presents a database that includes information on national recipes and their ingredients for 171 countries, measures for food taste similarities between all 171 countries as well as bilateral migration and agro-food trade data for 5 years. The database can be used for analyzing e.g., the relation between food preferences and international trade or food preferences and health outcomes (e.g., obesity) across countries.

Obesity promotes the development of insulin resistance and increases the incidence of colitis-associated cancer (CAC), but whether a blunted insulin action specifically in intestinal epithelial cells (IECs) affects CAC is unknown. Here, we show that obesity impairs insulin sensitivity in IECs and that mice with IEC-specific inactivation of the insulin and IGF1 receptors exhibit enhanced CAC development as a consequence of impaired restoration of gut barrier function. Blunted insulin signalling retains the transcription factor FOXO1 in the nucleus to inhibit expression of Dsc3 , thereby impairing desmosome formation and epithelial integrity. Both IEC-specific nuclear FoxO1ADA expression and IEC-specific Dsc3 inactivation recapitulate the impaired intestinal integrity and increased CAC burden. Spontaneous colonic tumour formation and compromised intestinal integrity are also observed upon IEC-specific coexpression of FoxO1ADA and a stable Myc variant, thus suggesting a molecular mechanism through which impaired insulin action and nuclear FOXO1 in IECs promotes CAC. Obesity is associated with an increased risk of colitis-associated cancer (CAC). Here Ostermann et al. show that a high-fat diet induces insulin resistance in intestinal epithelial cells (IECs) and that genetic inactivation of insulin and IGF1 signalling in IECs impairs intestinal regeneration and enhances tumour formation in a CAC mouse model.

Transcatheter techniques for the treatment of tricuspid regurgitation (TR) are being more frequently used and several new devices are in development. Since 90% of patients with TR have secondary TR, catheter based systems which reduce the dilated tricuspid annulus area are of particular interest. In order to perform an annuloplasty procedure effectively and safely, knowledge about the anatomy of the tricuspid valve apparatus and especially of the annulus in relation to the important neighboring structures such as the aortic root, the RCA, the electrical pathways and the CS is fundamental. In addition, comprehensive understanding of the device itself, the delivery system, its maneuverability and the individual procedural steps is required. Furthermore, the use of multi-modality imaging is important. For each step of the procedure the appropriate imaging modality as well as the optimal; imaging planes are crucial to provide the necessary information to best guide the individual procedural step.